Abdelhakim Elmouwahidi

Esther Bailón-García

Agustín F Pérez-Cadenas

Alain Celzard

Vanessa Fierro

Francisco Carrasco-Marín

Carbon microspheres with tailored texture and surface chemistry as electrode materials for supercapacitors

Keywords: Carbon microsphere, CO 2 activation, Nitrogen doping, supercapacitor

Introduction

Batteries offer a high energy density and will therefore continue to provide power for many electronic devices. However, although batteries are capable of achieving remarkable energy densities, the same cannot be said for their power density, i.e., their energy storage capacity is very high, but they are not able to deliver it in short times. [START_REF] Simon | Where Do Batteries End and Supercapacitors Begin?[END_REF] Batteries must work in a linear and more constant way; otherwise, their temperature may rise and thus reduce their lifespan. Consequently, in applications that require high power in short times, for example in electric engines, batteries have a disadvantage. [START_REF] Smith | Using Supercapacitors to Improve Battery Performance[END_REF] It is at this point that supercapacitors should play a role in supporting batteries in many electric applications. [START_REF] Simon | Where Do Batteries End and Supercapacitors Begin?[END_REF][START_REF] Smith | Using Supercapacitors to Improve Battery Performance[END_REF] Indeed supercapacitors, unlike batteries, work like accumulators, delivering stored electrical energy almost instantaneously. [START_REF] Luo | Overview of Current Development in Electrical Energy Storage Technologies and the Application Potential in Power System Operation[END_REF] Moreover, the charging time of supercapacitors is very low (1 second) compared to batteries (3-5 min) [START_REF] Miller | Electrochemical Capacitors: Challenges and Opportunities for Real-World Applications[END_REF] and the supercapacitor can be charged and discharged an almost unlimited number of times. [START_REF] Elmouwahidi | Activated Carbons from KOH and H3PO4-Activation of Olive Residues and Its Application as Supercapacitor Electrodes[END_REF] Supercapacitors are ideal devices when rapid charging is required to meet a short-term energy need, whereas batteries are chosen to provide long-term energy. Therefore, attempts to couple lithium-ion batteries and supercapacitors are more than encouraging. [START_REF] Dubal | Hybrid Energy Storage: The Merging of Battery and Supercapacitor Chemistries[END_REF][START_REF] Lukatskaya | Multidimensional Materials and Device Architectures for Future Hybrid Energy Storage[END_REF] From this perspective, supercapacitors are very interesting and are the subject of extensive research for their integration in electric cars. [START_REF] Bisschoff | Integration of Battery and Super-Capacitor Banks into a Single-Power System for a Hybrid Electric Vehicle[END_REF][START_REF] Embrandiri | An Electric Vehicle Conversion Using Batteries and Ultracapacitors[END_REF] This integration of supercapacitors would also bring other advantages: supercapacitors can help to significantly reduce the recharging times of electric cars and, given their ability to perform an almost infinite number of cycles, they can protect the batteries when the engine is turned on and off, thus increasing the lifetime of the batteries. This is the reason why they are already being applied to Start-Stop systems that are so popular in the automotive market to improve vehicle efficiency and reduce fuel consumption and emissions of combustion engines. Moreover, the technology associated with supercapacitors would also have a positive impact on the amount of energy collected by regenerative braking systems. Due to their high energy capacity and short charging times, a supercapacitor provides higher energy savings and a better braking absorption performance. [START_REF] Simon | Where Do Batteries End and Supercapacitors Begin?[END_REF] These technological developments will contribute to increasing the autonomy of electric cars. Consequently, research on supercapacitors is being promoted by the automotive industry. [START_REF] Allègre | Influence of Control Strategies on Battery/Supercapacitor Hybrid Energy Storage Systems for Traction Applications[END_REF] During the last decade, several carbon-based materials have been used as supercapacitor electrodes because of their high specific surface area, high electronic conductivity, high chemical stability, and low cost. [START_REF] Frackowiak | Carbon Materials for Supercapacitor Application[END_REF][START_REF] Zhou | Nanomaterials in Advanced Batteries and Supercapacitors[END_REF][START_REF] Li | Activated Carbon Fiber Derived from Sisal with Large Specific Surface Area for High-Performance Supercapacitors[END_REF] The capacitance can be enhanced by the presence of heteroatoms in the carbon network, which is a promising way to improve their electrochemical performance. [START_REF] Liu | Nitrogen-Doped Hierarchical Porous Carbon from Wheat Straw for Supercapacitors[END_REF][START_REF] Lu | Nitrogen-Doped Carbon Polyhedra Nanopapers: An Advanced Binder-Free Electrode for High-Performance Supercapacitors[END_REF][START_REF] Yan | S-Codoped Hierarchically Porous Carbon Spheres with Well-Balanced Gravimetric/Volumetric Capacitance for Supercapacitors[END_REF] Various heteroatoms have been used to introduce surface functional groups in the carbon materials such as nitrogen, [START_REF] Vivo-Vilches | Tailoring the Surface Chemistry and Porosity of Activated Carbons: Evidence of Reorganization and Mobility of Oxygenated Surface Groups[END_REF][START_REF] Kim | In Situ Formation of Nitrogen-Doped Onion-like Carbon as Catalyst Support for Enhanced Oxygen Reduction Activity and Durability[END_REF][START_REF] Elmouwahidi | Activated Carbons from KOH-Activation of Argan (Argania Spinosa) Seed Shells as Supercapacitor Electrodes[END_REF][START_REF] Hulicova-Jurcakova | Combined Effect of Nitrogen-and Oxygen-Containing Functional Groups of Microporous Activated Carbon on Its Electrochemical Performance in Supercapacitors[END_REF] phosphorus [START_REF] Elmouwahidi | Activated Carbons from KOH and H3PO4-Activation of Olive Residues and Its Application as Supercapacitor Electrodes[END_REF][START_REF] Fan | Hydrothermal Synthesis of Phosphate-Functionalized Carbon Nanotube-Containing Carbon Composites for Supercapacitors with Highly Stable Performance[END_REF] and oxygen [START_REF] Zhao | Oxygen-Rich Hierarchical Porous Carbon Derived from Artemia Cyst Shells with Superior Electrochemical Performance[END_REF][START_REF] Calvo | The Effect of the Carbon Surface Chemistry and Electrolyte PH on the Energy Storage of Supercapacitors[END_REF] . It has been shown that nitrogen doping can enhance the carbon surface properties, namely surface polarity, electrical conductivity, and electron-donor affinity, [START_REF] Lahaye | Porous Structure and Surface Chemistry of Nitrogen Containing Carbons from Polymers[END_REF][START_REF] Yan | A High-Performance Carbon Derived from Polyaniline for Supercapacitors[END_REF] which could significantly influence its electrochemical behaviour.

Nitrogen-containing porous carbon materials have been prepared using different nitrogen precursors such as melamine [START_REF] Elmouwahidi | Activated Carbons from KOH-Activation of Argan (Argania Spinosa) Seed Shells as Supercapacitor Electrodes[END_REF] and urea, [START_REF] Zhao | Hydrogen Uptake of High Surface Area-Activated Carbons Doped with Nitrogen[END_REF] which can modify the surface chemistry of the carbon after its synthesis. [START_REF] Elmouwahidi | Activated Carbons from KOH-Activation of Argan (Argania Spinosa) Seed Shells as Supercapacitor Electrodes[END_REF][START_REF] Zhao | Hydrogen Uptake of High Surface Area-Activated Carbons Doped with Nitrogen[END_REF] Another strategy is to subject a naturally N-rich precursor to carbonization, such as melamine [START_REF] Wang | A Melamine-Assisted Chemical Blowing Synthesis of N-Doped Activated Carbon Sheets for Supercapacitor Application[END_REF][START_REF] Friedel | Preparation of Monodisperse, Submicrometer Carbon Spheres by Pyrolysis of Melamine-Formaldehyde Resin[END_REF][START_REF] Pérez-Cadenas | Surface Chemistry, Porous Texture, and Morphology of N-Doped Carbon Xerogels[END_REF] or polyaniline, for the preparation of the nitrogen-enriched carbon materials [START_REF] Yan | A High-Performance Carbon Derived from Polyaniline for Supercapacitors[END_REF][START_REF] Zhu | Microorganism-Derived Heteroatom-Doped Carbon Materials for Oxygen Reduction and Supercapacitors[END_REF][START_REF] Schur | Neue Begr??Ndung Der Theorie Der Endlichen Transformationsgruppen[END_REF] in a single-step process.

The electrochemical performance of the supercapacitor can be influenced not only by the presence of heteroatoms on the carbon surface but also by its pore size distribution and surface area. [START_REF] Eftekhari | Surface Diffusion and Adsorption in Supercapacitors[END_REF] Therefore, the presence of a large surface area with a hierarchical pore size distribution is a crucial factor for a good capacitance. Different physical and chemical activation methods have been used to improve the textural properties of carbon materials such as chemical activation with KOH, [START_REF] Elmouwahidi | Activated Carbons from KOH-Activation of Argan (Argania Spinosa) Seed Shells as Supercapacitor Electrodes[END_REF][START_REF] Zapata-Benabithe | Surface Characteristics, and Electrochemical Double-Layer Capacitance of KOH-Activated Carbon Aerogels and Their O-and N-Doped Derivatives[END_REF] H 3 PO 4 , [START_REF] Elmouwahidi | Activated Carbons from KOH and H3PO4-Activation of Olive Residues and Its Application as Supercapacitor Electrodes[END_REF][START_REF] Li | The Role of H3PO4 in the Preparation of Activated Carbon from NaOH-Treated Rice Husk Residue[END_REF] CaCl 2 or ZnCl 2 [START_REF] Caturla | Preparation of Activated Carbon by Chemical Activation with ZnCl2[END_REF][START_REF] Vargas | Characterisation of Granular Activated Carbon Prepared by Activation with CaCl2 by Means of Gas Adsorption and Immersion Calorimetry[END_REF] or physical activation of the carbonized material with an oxidizing agent such as steam [START_REF] Prakash Kumar | Preparation of Steam Activated Carbon from Rubberwood Sawdust (Hevea Brasiliensis) and Its Adsorption Kinetics[END_REF][START_REF] Rodríguez-Reinoso | The Use of Steam and CO2 as Activating Agents in the Preparation of Activated Carbons[END_REF] or CO 2 [START_REF] Rodríguez-Reinoso | The Use of Steam and CO2 as Activating Agents in the Preparation of Activated Carbons[END_REF][START_REF] Zhang | Preparation of Activated Carbon from Forest and Agricultural Residues through CO2 Activation[END_REF][START_REF] Moreno-Castilla | Chemical and Physical Activation of Olive-Mill Waste Water to Produce Activated Carbons[END_REF] . Activation of carbons under CO 2 flow is one of the most effective methods for the development of their textural properties.

In this study, we report the synthesis and the electrochemical behaviour of N-doped carbon microspheres with a highly developed surface area as electrodes of supercapacitors. For this purpose, microspheres were synthesized using a mixture of resorcinol and formaldehyde and submitted to carbonization. The as-obtained carbon microspheres were first activated with CO 2 and then functionalized with N-containing groups to improve their electrochemical performance.

The effect of activation time on the surface area, pore size distribution and surface chemistry of the carbon microspheres was studied in-depth and related to the electrochemical performance of the corresponding supercapacitor electrodes.

Materials and methods

Materials

Resorcinol (99 %, Alfa Aesar), formaldehyde (37 %, Sigma-Aldrich), n-heptano (99.8 %, VWR), Span 80 (Sigma-Aldrich), Urea (99 %, Merck). Discs of 5 mm were cut from a graphite paper (240 m, Sigma-Aldrich) and glass microfibre filters (pore size 1.6 m) to be used as electrode and grassy fibrous separator, respectively.

Preparation of carbon microspheres

Carbon xerogel microspheres were prepared by inverse-emulsion sol-gel polymerization of resorcinol and formaldehyde in an organic medium. In a typical synthesis procedure, Span® 80 non-ionic surfactant (S) was dissolved in 900 mL of n-heptane and heated at 70 ºC under reflux and stirring (450 rpm). A mixture containing resorcinol (R), formaldehyde (F) and water (W) was pre-gelled at 65 ºC for 1 h and then added dropwise into the above solution. The molar ratios of the mixture were R/F = 1/2, R/W = 1/14 and R/S = 4.5.

The gel microspheres were aged at 70 ºC for 24 h under stirring after which the suspension was filtered and the resulting filtrate was placed in acetone (5 days, changing acetone twice daily) to exchange water within the pores for acetone aiming to reduces the collapse of porosity during the subsequent drying process [START_REF] Gallegos-Suárez | On the Micro-and Mesoporosity of Carbon Aerogels and Xerogels. The Role of the Drying Conditions during the Synthesis Processes[END_REF] and to remove the Span 80. Finally, the xerogel microspheres were dried by microwave heating under argon atmosphere (Ar flow is introduced by a hole input on the back of the microwave) in periods of 1 minute at 300 W until constant weight using a Saivod MS-287W microwave oven without temperature control, and then submitted to carbonization at 900 ºC for 2 h in a tubular furnace under a 300 cm 3 min -1 N 2 flow to obtain carbon xerogel microspheres. The final carbonization temperature was reached at a heating rate of 1 ºC min -1 in order to allow a gentle removal of pyrolysis gases.

The carbon xerogel microspheres (250 mg) were then activated at 900 ºC under CO 2 flow (60 cm 3 min -1 ) for times ranging from 30 to 120 min. The activated samples were labelled as S-X, where X is the CO 2 activation time. For example, S-30 refers to carbon microspheres that were activated for 30 min.

The CO 2 activated carbon microspheres were functionalized with nitrogen groups by mixing the microspheres with urea in a mass ratio of 1:1 and were then subjected to thermal treatment at 350 ºC under air flow (300 cm 3 /min) in a tubular furnace for 3 h. The nitrogendoped samples were referred to as S-X-U, where U refers to the urea treatment. In order of comparison, a sample with prepared using more amount of urea (carbon:urea mass ratio of 1:2)

was also synthesized (S-90-2U).

Textural and chemical characterization of carbon microspheres

The textural characterization of the carbon samples was carried out by adsorption of N 2 at -196 °C and CO 2 at 0 °C using an Autosorb-1 system and an ASAP 2020 equipment from Quatachrome and Micromeritics, respectively. The carbon samples were previously degassed at 120 ºC for 24 h under vacuum. The total micropore volume (W 0 (N 2 )) and the average pore diameter (L 0 (N 2 )) and the BET area (A BET ) were determined by application of the Dubinin-Radushkevich (DR) equation and the BET method to the N 2 adsorption isotherms, respectively, and the volume (W 0 (CO 2 )) and pore diameter (L 0 (CO 2 )) of narrow micropores were calculated using the DR equation applied to the CO 2 isotherms. The pore size distribution was determined by application of the Quenched Solid Density Functional Theory (QSDFT). The total pore volume (V 0.95 ) was considered as the volume of N 2 adsorbed at P/P 0 = 0.95. Mesopore volume V meso was obtained as V 0.95 -W 0 (N 2 ).

The chemical composition of activated carbons was obtained by elemental analysis using a CHNS elemental analyzer (ThermoFlash 1112) to determine carbon, hydrogen, nitrogen and sulfur contents by combustion of the samples in a stream of pure O 2 . The oxygen content was determined by difference.

The surface chemistry of the carbon samples was characterized by X-ray photoelectron spectroscopy using an Escalab 200R system (VG Scientific Co.) equipped with a Mg K X-ray source (hν = 1253.6 eV) and hemispherical electron detector. For the analysis of the XPS peaks, the C1s peak position at 284.6 eV was used as a reference to locate the other peaks. The fitting of the XPS peaks was done by minimizing least squares using Gaussian-Lorentzian peak sharps and a Shirley's type background.

The morphology of the carbon microspheres was studied by scanning electron microscopy (SEM) and optical microscopy using a LEO (Carl Zeiss) GEMINI-1530 microscope and an OLYMPUS BX51 microscope, respectively. The images were analyzed with an appropriate software (IJ.JAR, from Java) to determine the mean diameter of carbon microspheres and the corresponding histograms. For this, a minimum of 1000 particles were analyzed from different microphotographs and their diameter was calculated assuming a perfect spherical shape.

Electrochemical characterization

Preparation of carbon electrodes

Electrodes were prepared as follows: a mixture of 90 % of carbon and 10 % of PTFE ( 60% suspension in water) binder was prepared and dried overnight at 100 ºC. 5 mg of this dried mixture (containing 4.5 mg of active material) was pasted on a 5 mm graphite disc and pressed at 5 bars for a few minutes. Electrodes were impregnated with 1 mol L -1 H 2 SO 4 for 48 h before being used for the electrochemical measurements.

Electrochemical measurements

The electrochemical measurements were carried out in an EC-lab system at 25 °C using a two-electrode system. 1 mol L -1 H 2 SO 4 was used as electrolyte and a glassy fibrous material was used as separator. The electrochemical performance was analyzed in a voltage window of 0-0.9V. Cyclic voltammetry (CV) was performed at different scan rate (0.5, 2.5, 5, 10, 20 and 30 mV s -1 ) and the gravimetric capacitance, C CV (F g -1 ), obtained as described elsewhere. [START_REF] Elmouwahidi | Activated Carbons from KOH-Activation of Argan (Argania Spinosa) Seed Shells as Supercapacitor Electrodes[END_REF][START_REF] Moreno-Castilla | Symmetric Supercapacitor Electrodes from KOH Activation of Pristine, Carbonized, and Hydrothermally Treated Melia Azedarach Stones[END_REF] The galvanostatic charge-discharge tests were performed at current densities ranging from 0.125 to 7

A g -1 and the gravimetric capacitance, C GD (F g -1 ), was calculated as reported elsewhere. [START_REF] Zapata-Benabithe | Electrochemical Performance of Cu-and Ag-Doped Carbon Aerogels[END_REF][START_REF] Zapata-Benabithe | Carbon Xerogel Microspheres and Monoliths from Resorcinol-Formaldehyde Mixtures with Varying Dilution Ratios: Preparation, Surface Characteristics, and Electrochemical Double-Layer Capacitances[END_REF] The impedance spectroscopy measurements were carried out from 1 mHz to 100 kHz with AC amplitude of 10 mv. The electrical energies, E (Wh Kg -1 ) and power densities, P(W Kg -1 ) for the two-electrode cell system were calculated as described elsewhere. [START_REF] Moreno-Castilla | Symmetric Supercapacitor Electrodes from KOH Activation of Pristine, Carbonized, and Hydrothermally Treated Melia Azedarach Stones[END_REF][START_REF] Korenblit | High-Rate Electrochemical Capacitors Based on Ordered Mesoporous Silicon Carbide-Derived Carbon[END_REF] Cycling/Ageing experiments were performed at a current density of 1 A g -1 in the potential window between 0 and 0.9 V over 12000 charge-discharge cycles. More details were included in Supporting Information.

Results and Discussions

Morphology of the materials

The morphology of the pristine carbon microspheres was analyzed by optical and scanning electron microscopy, and representative images are shown in Figure 1a,b andc,d, respectively. It is clearly observed that carbon microspheres were successfully obtained by the inverse emulsion sol-gel polymerization of resorcinol and formaldehyde. These microspheres showed a perfect spherical morphology and a homogeneous size distribution with a mean size of 18 ± 3 m (Figure 1a,b and Figure S1). Note also that, despite most of the carbon microspheres retained this spherical structure after carbonization (Figure 1c), some damaged microspheres were also observed, which allows their internal morphology to be observed (Figure 1d). A typical structure of carbon gels is observed inside the carbon microspheres, which consists of a reticulated network of interconnected nano-sized primary particles leaving a mesoporous structure between them. Besides, the fairly homogeneous size distribution of these microspheres is also important in terms of packing and electrolyte diffusion in order to make real and functional electrodes for supercapacitors. A high packing density of 0.87 g cm -3 was obtained.

Textural and chemical properties

N 2 adsorption-desorption isotherms of the CO 2 -activated samples and their respective Ndoped counterparts are depicted in Figures 2a and2b, respectively. Based on the IUPAC classification, all samples exhibit mixed type-I and type-IV isotherms, representative of micro and mesoporous materials, respectively. The volume of N 2 adsorbed at low relative pressures increased with the activation time, indicating a predominantly micropore development during the CO 2 activation process. This increase is especially pronounced after 30 min of activation; however, activation times longer than 60 min increased N 2 adsorption but to a lesser extent. A similar tendency is observed for N-doped samples (Figure 2b). Nevertheless, lower N 2 -adsorbed volumes are obtained at lower relative pressures than their respective CO 2 -activated samples, indicating that the urea treatment reduced the surface area of the sample by blocking some porosity. [START_REF] Zhao | Hydrogen Uptake of High Surface Area-Activated Carbons Doped with Nitrogen[END_REF] The effect of the CO 2 -activation time and the urea treatment on the porosity of carbon microspheres was analysed in more detail from the N 2 and CO 2 adsorption data included in Table 1. As previously commented, the CO 2 -activation treatment of pristine carbon microspheres during 30 min caused an increase of surface area of 93 %, due to the opening of the existing ultra-microporosity and the creation of new, narrower, pores (the micropore volumes determined by N 2 and CO 2 adsorption, W 0 (N 2 ) and W 0 (CO 2 ), increased whereas the mesopore volume V meso remained almost constant). It is well known that CO 2 adsorption provides information about the ultra-microporosity, i.e., micropores with a diameter narrower than 0.7 nm, while the super-microporosity is obtained from N 2 isotherm only in absence of diffusion restrictions. For pristine carbon microspheres (S-0), W 0 (N 2 ) < W 0 (CO 2 ), denoting the presence of narrow micropores or pores with constricted entrances, which prevent the access of N 2 .

However, W 0 (N 2 ) > W 0 (CO 2 ) for CO 2 -activated samples, as a consequence of pore widening.

Note that L 0 (N 2 ) also increased, corroborating this pore widening. Thus, the increase of activation time up to 90 min increased the surface area, average pore diameter and pore volume.

However, the increase in activation time from 30 to 90 min caused an increase of surface area substantially lower (18.9 %, from 30 to 60 min and 9.9 % from 60 to 90 min) compared to that observed from 0 to 30 min of activation (93 %). The surface area decreases for longer activation times such as 120 min probably due to pore widening and merging. [START_REF] Zapata-Benabithe | Surface Characteristics, and Electrochemical Double-Layer Capacitance of KOH-Activated Carbon Aerogels and Their O-and N-Doped Derivatives[END_REF] Thus, a maximum surface area was obtained after 90 min of CO 2 activation (Figure 3a). Hence, two antagonistic factors act together when the CO 2 activation time increases; one is the creation and opening of a porosity inaccessible to N 2 molecules and the other is the micropore widening and pore merging due to the disappearance of walls between adjacent pores. At low activation time, the first effect predominates and strongly increases the surface area, but by increasing the activation time the second effect starts to be important; it reduces the increase in surface area and even decreases the surface area at a very high activation time.

The micropore size distribution of CO 2 -activated carbon microspheres is shown in Figure 4a. The micropore width of pristine microspheres (S-0) is very narrow and a well-defined peak is obtained at about 0.6 nm. Thus, some porosity could be inaccessible to N 2 molecules during adsorption at -196 °C. The intensity of this peak increased after 30 min of activation treatment (S-30), indicating the creation and opening of new ultra-microporosity, which highly increases the surface area. This intensity, as well as W 0 (N 2 ) (Figure 3b), slightly decreases while wider microporosity is created by increasing the activation time to more than 60 min (Figure 4a). This means that existing pores were destroyed or opened by excessively increasing the activating time due to the deterioration of the walls between adjacent micropores, which produced a reduction of surface area and micropore volume.

Regarding N-doped samples, the treatment with urea produced a decrease of the surface area compared to their respective CO 2 -activated samples (Table 1 and Figure 3a), due to a porosity blockage induced by the N-functionalization. However, the volumes of supermicropores (0.7-2 nm, Figure 4b) and mesopores (Table 1) decreased after the urea treatment. From this, it can be concluded that N-functionalization mainly occurs in wider porosity without blocking the ultramicropores entrance and thus, N-surface groups are localized on a surface completely accessible for electrolyte ions and thus, for electrochemical reactions. Note that the volume of pores narrower than 0.7 nm, W 0 (CO 2 ), (Table 1), were not modified after the Nfunctionalization. Additionally, it is also important to highlight that the micropore width of the samples, L 0 , which ranges from 0.62 to 1.27 nm, would be fully accessible to the hydronium ions, 0.36-0.42 nm, [START_REF] Li | The Role of H3PO4 in the Preparation of Activated Carbon from NaOH-Treated Rice Husk Residue[END_REF] and hydrated bisulphate ions, 0.53 nm, [START_REF] Caturla | Preparation of Activated Carbon by Chemical Activation with ZnCl2[END_REF] produced by dissociation of the electrolyte (1 mol L -1 H 2 SO 4 ).

The chemical nature of the bulk and surface of carbon materials was studied by elemental analysis and XPS, respectively, and results are collected in Table 2. From the results, it appears that CO 2 activation treatment did not affect the chemical nature of carbon spheres. All CO 2activated samples, regardless to activation time, present a very low N (<0.5 %) and a constant oxygen (about 5.5 %) contents, which are very close to the values obtained for the pristine carbon spheres (S0). Thus, the different electrochemical behavior of CO 2 -activated samples should only be related to their different textural characteristics since their chemical nature is quite similar. On the other hand, the treatment with urea highly increased the total N fixed on the carbon microspheres, whereas the O contents were not significantly modified. The amount of N fixed was around 4.0 ± 0.5 %, independently of the CO 2 -activation time and therefore of the surface area and pore volume, except for the S-120-U sample in which the N content is slightly lower. Oxygen groups on carbon play a crucial role in the binding with nitrogen precursors, by providing active sites that promote the reaction with the N-doping molecules and N-integration in the carbon structure. [START_REF] Mou | Forming Mechanism of Nitrogen Doped Graphene Prepared by Thermal Solid-State Reaction of Graphite Oxide and Urea[END_REF][START_REF] Huang | Different Types of Nitrogen Species in Nitrogen-Doped Carbon Material: The Formation Mechanism and Catalytic Role on Oxygen Reduction Reaction[END_REF][START_REF] Li | Simultaneous Nitrogen Doping and Reduction of Graphene Oxide[END_REF][START_REF] Sheng | Catalyst-Free Synthesis of Nitrogen-Doped Graphene via Thermal Annealing Graphite Oxide with Melamine and Its Excellent Electrocatalysis[END_REF][START_REF] Li | Facile Synthesis of Nitrogen-Doped Graphene via Low-Temperature Pyrolysis: The Effects of Precursors and Annealing Ambience on Metal-Free Catalytic Oxidation[END_REF] Mou et al. [START_REF] Mou | Forming Mechanism of Nitrogen Doped Graphene Prepared by Thermal Solid-State Reaction of Graphite Oxide and Urea[END_REF] found that certain oxygen-containing functional groups in graphene oxide were responsible for reacting with the amino-groups of urea to form C-N bonds and allow N-doping. They therefore proposed that the process of formation of N-doped graphene starts with the reaction of amide and/or ammonia (produced by urea decomposition)

with oxygen-containing functional groups in graphene sheets to form amidated graphene below ∼300 °C. Then, amide N in amidated graphene is transformed to pyrrolic N and pyridinic N at the graphene edges and/or at defect sites between 300 and 500 °C. Here, the N % incorporated into the carbon network after the urea functionalization treatment of all CO 2 -treated carbon microspheres (S-X-U series) is quite similar since the oxygen content of all CO 2 -activated samples is almost the same. Even with twice the amount of urea (S-90-2U), the N content (3.9 %) was the same as that obtained when using a lower amount of urea (3.8 %). This fact seems to indicate that, in this study, the oxygen content was the limiting factor in the N-doping rather than the accessible surface area for urea functionalization.

Comparing the total and surface N contents, N E.A. and N XPS respectively, it is observed that these two values are quite similar, indicating a homogeneous N distribution along the material surface. Conversely, O E.A. is much higher than O XPS , indicating that most of this O is mainly a component of the carbon bulk structure. The nitrogen content will have an important effect on the electrochemical performance of the supercapacitors prepared. [START_REF] Wang | A Melamine-Assisted Chemical Blowing Synthesis of N-Doped Activated Carbon Sheets for Supercapacitor Application[END_REF][START_REF] Wickramaratne | Nitrogen Enriched Porous Carbon Spheres: Attractive Materials for Supercapacitor Electrodes and CO2 Adsorption[END_REF] In order to obtain additional information about the nature of the N bonding, the N 1s spectral region was deconvolved for urea-treated carbon microspheres and the corresponding results are collected in Table 2 and Figure S2. Three peaks are required for such deconvolution, which reveals the coexistence of three types of nitrogen: pyridinic-N (N-6) at 398.4 eV, pyrrolic-N or pyridone-N (N-5) at 400.1 eV, and quaternary nitrogen (N-Q) at 401.1 eV. [START_REF] Zapata-Benabithe | Surface Characteristics, and Electrochemical Double-Layer Capacitance of KOH-Activated Carbon Aerogels and Their O-and N-Doped Derivatives[END_REF][START_REF] Gorgulho | Synthesis and Characterization of Nitrogen-Doped Carbon Xerogels[END_REF][START_REF] Kiciński | Heterogeneous Carbon Gels: N-Doped Carbon Xerogels from Resorcinol and n-Containing Heterocyclic Aldehydes[END_REF] Note that N-6 and N-5 predominate (around 90 % of total N) in all urea-treated carbons. Moreover, this distribution of N functionalities does not depend on the activation time of the carbon microspheres (Table 2). N-6 and N-5 functionalities could provide chemically active sites for pseudocapacitive reactions. [START_REF] Wang | N-Doped Carbon Spheres with Hierarchical Micropore-Nanosheet Networks for High Performance Supercapacitors[END_REF] The electron-rich nature of these nitrogen sites indeed enhances the carbon basicity through a strong  delocalization in graphene layers and therefore, protons from the electrolyte can be attracted to the electrode surface and produce an enhancement in the capacitive behaviour in acidic electrolytes associated with the presence of these pseudocapacitive interactions. [START_REF] Zapata-Benabithe | Surface Characteristics, and Electrochemical Double-Layer Capacitance of KOH-Activated Carbon Aerogels and Their O-and N-Doped Derivatives[END_REF][START_REF] Hulicova | Electrochemical Performance of Nitrogen-Enriched Carbons in Aqueous and Non-Aqueous Supercapacitors[END_REF] N-Q can also increase the capacitance because graphene sheets with N-Q functionalities could be more positively charged when used as an anode material in supercapacitors, attracting more the ions charged negatively, thereby increasing the capacitance.

Alike nitrogen functional groups, oxygen functionalities also affect the capacitance of supercapacitors oxygen functionalities also affect the capacitance of supercapacitors. Therefore, O 1s spectral region was also deconvolved (Table 2 and Figure S2). In this case, two peaks are required for such deconvolution at 531 eV and 533 eV attributed to C=O and C-O bonds, respectively. However, note that O content and O-functionalities distribution is quite similar for all samples (N doped and undoped), consequently, the different electrochemical performed should be ascribed to the different textural properties and nitrogen functionalization.

Electrochemical properties

S-X-U samples combine a high surface area with a high nitrogen content and hence, the derived supercapacitors are expected to have a significant capacitive and cycling performance. curves were obtained for N-doped carbon microspheres. Moreover, the enclosed area of the CVs of N-doped samples is much higher than the one obtained for their respective CO 2 -activated samples, despite their lower surface area and narrower pore width. This suggests a decrease in the internal resistance and an enhanced specific capacitance (Table 3) after nitrogen doping [START_REF] Elessawy | Development of High-Performance Supercapacitor Based on a Novel Controllable Green Synthesis for 3D Nitrogen Doped Graphene[END_REF] that might be attributed to better ion transport, better wettability and higher electrical conductivity provided by the nitrogen functional groups. Figure 6a and b depicts the cyclic voltammograms at different scan rates for the sample S-90 and S-90-U, respectively. Note that the CV curves is deviated from the classical rectangular waveform, expected for a pure capacitor for the CO 2 treated sample (S-90), whereas this rectangular shape is maintained for N-doped sample (S-90-U) even at very high scan rate denoting the effect of the N-functional groups into the ion transport and the formation of the electrochemical double layer within the micropores.

This fact was studied in more detail by analyzing the variation of the electrode capacitance as a function of scan rate (0.5-30 mV s -1 ) displayed in Figure 5c andd. The specific electrode capacitance decreases as the scan rate increases because the formation of the electrochemical double layer (EDL) within the micropores is slower and less complete. At low scan rates, the electrolyte ions can easily diffuse and penetrate deeper into the material porosity, resulting in greater ion adsorption and therefore more effective interaction between the electrolyte and the electrode material and hence to a higher specific capacitance. [START_REF] Ali | Electrochemical Performance Studies of MnO2 Nanoflowers Recovered from Spent Battery[END_REF] As the scan rate increases, the diffusion of electrolyte ions within the porous structure of the carbon becomes more difficult, and ineffective interactions between the electrolyte and electrode material occur, therefore the specific capacitance therefore decreases. Nonetheless, it should be noted that the decrease of the specific capacitance is more pronounced in CO 2 -activated samples than in their respective Ndoped counterparts, in spite of the porosity blockage and pore width narrowing observed after functionalization. This clearly indicates that nitrogen surface groups favour capacitance retention. As commented, the electron-rich nature of N-6 and N-5 functional groups enhances the carbon basicity through a strong  delocalization in graphene layers and, therefore, the protons of the electrolyte can be attracted to the electrode surface, which promotes diffusion and adsorption of ions even at higher scan rates.

Galvanostatic charge-discharge tests were also performed and the results are shown in Figure 7. Similar conclusions can be obtained. The better capacitive behavior of N-doped samples regarding their CO 2 -activated counterparts was also evidenced by their more triangular shape. It can be clearly seen that the charge/discharge curves of N-doped carbon microspheres are linear and symmetrical with low iR drops whereas asymmetrical curves with higher iR drops are observed for CO 2 -activated samples, manifesting that the N-doping affects the currentvoltage response and the electrochemical reversibility. The higher capacitance retention of Ndoped samples is also pointed out in Figure 7c andd, indicating a lower electric resistance and a better diffusion of the electrolyte into the pore favored by the presence of N-surface groups.

The effect of the porous texture can be elucidated from Figure 5a and 7a since, as it was pointed out in the previous section, CO 2 -activated samples present a very similar surface chemistry. The enclosed area of the CVs and CPs for CO 2 -activated samples increases in the sense S-0 < S-120 < S-30 ≈ S-60 < S-90. As expected, a very low electrode capacitance, C GD and C CV (Table 3), was obtained for the pristine carbon microspheres and this value increased with the activation time up to 90 min, due to the increase of available surface area for the development of the EDL. It is well known that the gravimetric capacitance increases with the micropore volume and surface area, indicating that both are key parameters for EDL formation on carbon-derived electrodes. [START_REF] Elmouwahidi | Activated Carbons from KOH and H3PO4-Activation of Olive Residues and Its Application as Supercapacitor Electrodes[END_REF][START_REF] Zapata-Benabithe | Effect of Dilution Ratio and Drying Method of Resorcinol -Formaldehyde Carbon Gels on Their Electrocapacitive Properties in Aqueous and Non-Aqueous Electrolytes[END_REF] The specific capacitance decreased after 120 min of activation due to the decrease in surface area and the pore widening observed at high activation time. A similar trend was obtained for N-functionalized samples; the higher the surface area and micropore volume, the higher the specific capacitance. Nonetheless, the capacitance proportionally increased for all activation times after N-doping, denoting that Nfunctionalization affects the capacitance in a similar extent for all activation times due to the similar N content of all samples. In conclusion, the sample S-90-U had the best electrochemical performance because it combines high surface area and optimum pore size distribution with nitrogen functionalities, resulting in a high electrode capacitance (228 F g -1 at 0.125 A g -1 ).

Moreover, as a consequence of its high packing density, the carbon microspheres (S-90-U) exhibit large volumetric capacitance (199 F g -1 at 0.125 A g -1 ) which is very important to make real and functional electrodes for supercapacitors. This high volumetric capacitance is comparable or superior to most of the values reported in the literature (see Table 4).

The resistance to the diffusion of the electrolyte inside the carbon pores can be measured by electrochemical impedance spectroscopy, EIS. The interfacial charge transfer resistance, R CT , caused by the electric double layer capacitance and Faradaic reactions was also calculated from the two intercepts of the semicircle with the real axis, [START_REF] Elmouwahidi | Activated Carbons from Agricultural Waste Solvothermally Doped with Sulphur as Electrodes for Supercapacitors[END_REF] and the corresponding values are included in Table 5. R CT values were lower for N-functionalized carbon microspheres than for their CO 2 -activated counterparts. This The relaxation time constant (), see Table 5, which is a quantitative measure of the time necessary for the total discharge of the supercapacitors, [START_REF] Zhang | Preparation of Activated Carbon from Forest and Agricultural Residues through CO2 Activation[END_REF] can be obtained from the frequency, f 0 , at the maximum of the curves of the imaginary part of the capacitance, by the equation 1 ( 2. Smaller values of τ were obtained for N-doped samples and specifically with S-30-U and S-90-U, which indicates a better supercapacitor response.

The cyclic stability of supercapacitors is one of the main factors that can hinder their practical application. For this reason, Figure 9 shows the variation in the gravimetric electrode capacitance with the number of charge-discharge cycles at 1 A g -1 to assess the long-term stability of electrodes. All samples exhibit good long-term stability. Nonetheless, N-doped samples exhibit virtually no loss of capacitance after 12000 cycles in comparison with the 95% of capacitance retention of their CO 2 -activated counterparts (Table 3), suggesting an improved stability provided by the N-functionalization. Ragone plots obtained from galvanostatic discharge at different current densities are displayed in Figure 10 and the maximum and minimum energies and power densities are listed in Table 5. Both the maximum energy density (E max ) and the maximum power density (P max ) increased with activation time up to 90 min, which was attributed to the pore structure developing better by increasing the activation time. This maximum energy is at least twice as high for N-doped samples as for their CO 2 -activated counterparts, demonstrating the beneficial effect of N-surface groups in improving the wettability and the mobility of ions in the microporous network. The superior performance of the sample S-90-U is due to its more developed porosity associated with the presence of nitrogen surface groups.

Conclusion

Carbon microspheres having high surface areas and porosity were synthesized thanks to a simple CO 2 activation pre-treatment before N-doping. N-doped carbon microspheres, with remarkably high amounts of N functionalities, very well distributed throughout the entire carbon matrix, were prepared by mixing carbon microspheres with urea and subjecting them to a temperature of 350 °C in air. These special textural and chemical characteristics are highly desirable for high-performance supercapacitors, which in our best cases had electrode capacitances of 235 F g -1 combined with 100% cyclability after 12000 charge-discharge cycles.

Besides, the fairly homogeneous size distribution of these microspheres is also important in Table 1. BET area (A BET ), micropore volume (W 0 ), total pore volume (V 0.95 ), mesopore volume (V meso ) and average pore diameter (L 0 ) of the activated and doped samples.

Sample N 2 at -196 ºC CO 2 at 0 ºC A BET L 0 (N 2 ) W 0 (N 2 ) V 0.95 (N 2 ) V meso (N 2 ) L 0 (CO 2 ) W 0 (CO 2 ) m 2 g -1 nm cm 3 g -1 cm 3 g -1 cm 3 g -1 nm cm The gravimetric capacitance, C (F/g), was obtained from galvanostatic charge-discharge tests by equation 2: [START_REF] Zapata-Benabithe | Electrochemical Performance of Cu-and Ag-Doped Carbon Aerogels[END_REF][START_REF] Zapata-Benabithe | Carbon Xerogel Microspheres and Monoliths from Resorcinol-Formaldehyde Mixtures with Varying Dilution Ratios: Preparation, Surface Characteristics, and Electrochemical Double-Layer Capacitances[END_REF] (Eq. 2)

where I d is the discharge current, Δt the discharge time, m the total mass of the active material in the electrodes, and ΔV the voltage interval after the ohmic drop.

For performance comparisons, the gravimetric capacitances in two-electrodes configuration (2EC) were multiplied by four to obtain the expression per single electrode, (C CV and C GD , from cyclic voltammetry and galvanostatic charge-discharge tests, respectively) which is the 3electrode configuration (3EC) equivalent. [START_REF] Rufford | Double-Layer Capacitance of Waste Coffee Ground Activated Carbons in an Organic Electrolyte[END_REF] The electrical energy and the power density were calculated by using the Eq. 3 and Eq. 4, respectively for two-electrode cell: [START_REF] Korenblit | High-Rate Electrochemical Capacitors Based on Ordered Mesoporous Silicon Carbide-Derived Carbon[END_REF] (Eq. 3)

(Eq. 4)

where ΔV is the operation voltage taken as ΔV= V max -IR drop , Δt is the discharge time (h) and C are the values of the capacitances obtained from Eq. 2.

Figure 5a and b show

  Figure 5a and b show cyclic voltammograms (CVs) at 0.5 mV s -1 of the CO 2 -activated carbon

  Figure 8a and b present the EIS spectra in the form of Nyquist plots for both CO 2 -activated and N-doped carbon microspheres, respectively. The values of the equivalent series resistance (ESR) of all the samples are listed in Table 5. The ESR results in three resistances: the intrinsic resistance of the active material, the electrolyte resistance and the active material/current collector interface resistance. Since the same electrolyte, collectors, and technique were used to assemble the cell, the ESR can be related to the conductive properties of the activated carbon electrodes for comparison purposes. All samples present low ESR values, indicating a facile electron and ion transport/diffusion in the carbon porosity. However, the ESR values of the N-functionalized samples are typically the half of their respective CO 2 -activated samples indicating, as it was previously commented, that surface nitrogen groups favor the diffusion of ions and enhance the conductivity of carbon materials.

  indicates a faster charge transfer and a better accessibility of electrolyte ions into pores of the electrode materials due to the presence of N-surface groups. The R CT values for S-60-U and S-90-U are the lowest, showing that ion transport is the easiest and fastest for those samples due to the combination of a good conductivity and a good ion diffusivity provided by the N-surface groups and the large and accessible porosity provided by CO 2 -activation. It is also important to highlight that S-0 and S-0-U present the highest ESR and R ct values of their respective series due to their narrowest pore size distributions, which make it difficult for the electrolyte to diffuse within the carbon porosity.

Figure 1 .

 1 Figure 1. Optical (a and b) and SEM (c and d) images of pristine carbon microspheres.

Figure 2 .Figure 3 .Figure 4 .

 234 Figure 2. N 2 isotherms at -196 °C of (a) CO 2 -activated carbon microspheres and (b) N-doped carbon microspheres. Samples: S-0 and S-0-U (○), S-30 and S-30-U (□), S-60 and S-60-U (◇),

Figure 5 .

 5 Figure 5. Cyclic voltamograms of: (a) CO 2 -activated and (b) N-functionalized samples at a scan rate of 0.5 mV s -1 . Variation of the electrode capacitance as a function of scan rate for: (c) CO 2activated and (d) N-doped carbon microspheres. Samples: S-0 and S-0-U (○), S-30 and S-30-U

Figure 6 .Figure 7 .

 67 Figure 6. Cyclic voltamograms of: (a) CO 2 -activated and (b) N-functionalized samples at different scan rates for samples (a) S-90 and (b) S-90-U. (△), 0.5; (◇), 5; (), 10; (○), 20 and (□), 30 mV s -1 .

Figure 8 .

 8 Figure 8. Nyquist plot of the electrodes based on: (a) CO 2 -activated and (b) N-doped carbon microspheres. S-0 and S-0-U (○), S-30 and S-30-U (□), S-60 and S-60-U (◇), S-90 and S-90-U

Figure 9 .

 9 Figure 9. Variation of the gravimetric electrode capacitance (C GD ) with the number of chargedischarge cycles at a current density of 1 A g -1 in the potential window between 0 and 0.9 V for a) CO 2 -activated and b) N-doped carbon microspheres. Samples: S-0 and S-0-U (○), S-30 and S-

Figure 10 .

 10 Figure 10. Ragone plots of all carbon microspheres in 1 mol L -1 H 2 SO 4 for: (a) CO 2 -activated and (b) N-functionalized carbons microspheres. Samples: S-0 and S-0-U (○), S-30 and S-30-U

Figure S1 .

 S1 Figure S1. Particle size distribution of carbon microspheres obtained from the analysis of optical microscopy images.

Figure S2 .

 S2 Figure S2. XPS spectra of urea-treated carbon microspheres: (a) N 1s and (b) O 1s

Table 2 .

 2 Elemental analysis (E.A.) and XPS of non-doped and N-doped carbon microspheres.

	3 g -1

Funding Sources

Ministry of Science, Innovation and Universities (RTI2018-099224-B-I00) Junta de Andalucía (P12-RNM-2892 and RNM172) Generalitat Valenciana (APOSTD/2019/030) ACKNOWLEDGMENT This work was supported by Spanish Ministry of Science, Innovation and Universities -State Research Agency-_Project ref. RTI2018-099224-B-I00 and Junta de Andalucía (grant numbers

terms of packing and electrolyte diffusion in order to make real and functional electrodes for supercapacitors.

ASSOCIATED CONTENT Supporting Information. The following files are available free of charge.

Author Contributions

The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. Table 3. C CV at 0.5 mV s -1 ; C GD at 125 mA g -1 , R 2 and R 7 : capacity retention at 2 and 7 A g -1 against 0.125 A g -1 , respectively and retention capacitance after 12000 charge-discharge cycles of GCD at 0.125 A g -1 .

P12-RNM-2892, RNM172

Sample

Supplementary Materials

Gravimetric capacitances, C (F/g), were obtained from the cyclic voltammetry curves by Equation (1): [START_REF] Elmouwahidi | Activated Carbons from KOH-Activation of Argan (Argania Spinosa) Seed Shells as Supercapacitor Electrodes[END_REF][START_REF] Moreno-Castilla | Symmetric Supercapacitor Electrodes from KOH Activation of Pristine, Carbonized, and Hydrothermally Treated Melia Azedarach Stones[END_REF] (Eq. 1)

where was the area of the current (A) against time (s) curve, Δt the discharge time, m the total mass of the carbon material in the electrodes, ΔV the voltage interval after the ohmic drop.


Georges-Jean Pinault

New material extracted from revised Tocharian A texts

Complementary methods for understanding texts, and gaining the meaning of words.

1) The internal method, based on the structure of the Toch. text, and its internal logic, completed by the combinatorial method, i.e., confrontation of other Toch. texts.

2) The external method, resorting to parallel texts in other languages of Buddhism.

3) The contextual method, resorting to Indian and Buddhist culture, literature, arts, etc., and/or to the historical and cultural context of Central Asia, especially, but not exclusively, Tarim Basin. § 1. Reminder (Pinault 2019). Leaf of the MSN. A 285+281 (THT 918+914), plus little fragment THT 1408.k, giving the left corner of the leaf. OT parallel: MaitrHami V, 2 b14 to 4 a4. Sanskrit parallel: two texts at least, one (MPS) about the division and cult of the relics of the Buddha, and the other about the decadence and improvement of the living beings. Meaning of the root TA ok-(TB auk-) 'to produce, show', translated by OT b(ä)lgür-. Compare Malzahn (2010): 'to set in motion', not 'to give to drink'. Fitting all other uses of

the verb, with the immortality (TA oṅkraci) or 'the medicine of immortality' (TB sāṃtke … onwaññe) as direct object. Evident IE etymology: *h 2 e g-'to increase, let grow'.

TA yri 'fence, enclosure ' = Skt. vedikā-. Standard description of wonderful cities (Ketumatī, Kuśavatī, etc.), see MSP, Maitreyavyākaraṇa, etc.

TA wpāl = OT kül 'ashes' ; verbal noun of TA wäp ā -'to consume'. No gloss in [START_REF] Malzahn | The Tocharian Verbal System[END_REF].

TA puśeṃ, new title of the Buddha, cognate with TB puś and adjective TB puśamaṣṣe.

Derived from TA/TB puś 'Buddhahood'. Probably of Iranian origin.

N.B. While TA/TB texts are adaptations or translations of Sanskrit texts, several terms of the Buddhist terminology show some degree of Middle Iranian influence. § 2. New reading of a well-known text: Tale of the four masters of arts and the lion, part of the Puṇyavanta-jātaka. A 11 b2 to 13 a5 . Sieg 1944: 14-16 first translation by [START_REF] Sieg | Die Geschichte von den Löwenmachern in tocharischer Version[END_REF].

Description of the lion still asleep.

12 b3-5.

kākropu puk ś(twar pe)yu ; lyäṣknaṃ ywārśkā si cacp u ku : kliso pāccās poṣṣāsā ; to lap śālyiṃ kolyeyac : ākaṃ yoktsās klośäṃ tsru ; lalku śaśmu śiśri koc : śāmāṃ śiśkäṣ klisontäṣ ; śoll ats cami wākäm ṣeṣ : 1

Translation: The four feet had he all fold up, he had hidden his tail between his thighs; lying on the right side, having placed his head toward the left paw. He let hang a little the ears, provided with hairs on their tips, (but) he had his whiskers raised upwards. Only life made him different from a living sleeping lion. DN II, 164: jhāyamānassa kho pana bhagavato sarīrassa yam ahosi chavīti vā cammanti vā maṃsanti vā nhārūti va lasikāti va, tassa neva chārikā paññāyittha, na masi. DN II, 336: 'tena hi bho, imaṃ purisam anupahacca chaviñca cammañca maṃsañca nhāruñca aṭṭhiñca aṭṭhimiñjañca jīvitā voropetha, appeva nāmassa jīvaṃ nikkhamantaṃ passeyāmā' ti. In all these lists, from outside to inside, the order of terms for the skin is always: P. chavicamma-= Skt. chavi-'skin' vs. carman-'hide, skin, leather'. Then TA yats (B yetse) = chavi-vs. TA krāṃ (TB krāna) = carman-. Skt. chavi-refers to the surface of the skin, 'outer skin', to the complexion, see the evolution inside Sanskrit towards 'color'. In such binomial phrases, it was always possible to reduce the pair to a single item, for instance TB yetse or TA krāṃ. Tentative translation: (102) Through the decay (kāṣāya-) pertaining to being (sattva-), rule (kalpa-), afflictions (kleśa-), views ( ṣṭi-), and time (āyuṣ-), the mind of the living beings got lost. (103) They were, friends as well as enemies, bound to evil [and] wicked. No living beings at all indeed did refrain from evil. Kings, ministers, clerks, depraved men, judges, (people) belonging to suburbs and villages, did take wrongly the law. (104) They were avid from birth, searching for profit [and] gain. Through the greed linked to injustice, the beings in the countries were deluded. Then [if] ceremonies happen to be performed by them, wind [and] rain made troubles for them. And for these ones the canes did not ripen nor develop at right time. (105) The tree (was) producing that (weird) fruit, not having matured correctly. Following immediately that their mind got lost. They become ugly in their aspect. The afflictions held off the touching of the viaticum. Joyfulness disappeared for sure. Even by making efforts, the blessing (obtained) through the feeling of disgust was difficult (to reach). ( 106) The Buddha-lord made continuously unlimited effort in order to make these beings feeling disgust. For a long time, they were not feeling disgust, even for a single moment. This excellent sage from the Śākya-clan (= Śākyamuni) had a brother called Nanda, the beautiful one (saundara-), the younger brother of the sage from the same father. ( 107) Through huge effort [and] zeal the Buddha lord took him away from home (= from householder-life). His mind was clung to the woman, he did not consent to feel disgust. He (the Buddha) led him to the sages, thereafter he led him to the gods, afterwards, whenever he led him in hell, this one (Nanda) felt disgust. ( 108) Devadatta had learned the Law, the three baskets (tri-piṭa-) completely. Like the scallop (lit. having shell) during twelve years he observed the observance. He sat in meditation; this one rose up to the controlling of supernatural power ( -). Through the admiration, through the honors (which he received), the mind of that one turned wholly astray [and] perverse. ( 109) He went far from the way of the Law, and he tried to kill the Buddhalord. He committed the deadly sins (anantariya-); finally he fell in the Avīci hell. This one had a pupil named Kokālika, having become a monk (lit. having left home). He expressed (lit. set) blame [and] slander, in addition even on Śāriputra (lit. the son of Śāri), ( 110) and even on Maudgalyāyana. The god Brahmā himself restrained him. Even the Buddha-lord, the teacher restrained him again three times. From his way this one did not consent finally to refrain. He fell in the Mahāpadma (hell). By five hundred plowmen his own (tongue was plowed) in the hells. ( 111) Sunakṣatra crushed tiny animals; after having strewn them on the footprint of the Buddha-lord, he kept saying: 'From where has this one his virtue consisting in Buddhahood?' There was a householder called Śrīgupta, provided with means of killing. He covered for him a ditch with carpets above. He mixed poison in his (i.e., of the Buddha) meals. ( 112) Aṅgulimāla killed living beings, little less than 10.000 at once. Now he intended to kill his own mother. Through his power, the Buddha-lord went towards him at that time. Now, he decided to kill the Buddha-lord. He did not go to his goal. Then he became an Arhat: higher was the teacher. (113) There was at that time a king called Ajātaśatru, an evil one. This one, after having killed his own father, turned perversely in presence of the Buddha-lord. But finally he made the confession (deśanā-). § 4. A 381 (THT 1015). Preparation for the confession (deśanā) of a nun (bhikṣuṇī) before the assembly of monks and nuns. To be compared (partly) to A 371 (THT 915). Complete text. Verso, not in TochSprR(A), also ruled, but only part of the line 1 has been written, by a different hand: b1. /// ntāṃ āṣānikāṃ āmpe pissaṅkäṃtwe • ñuk täṣne ñomā aśi • śoṣi saṅkāvaśeṣäṃtu (blank), four next lines not written: kind of rough draft. The list of offences is not complete, nor exactly in the same order as in parallel texts: a2. sexual passion (R. 4), go-between for rendez-vous (R. 1), a3. injuring or deprecatory speech, quarrel (R. 14, R.16, R.17, R.18), corrupter of families (R. 19), accusing for a pretext (R.3), a4. being/travelling alone, day and night (R. 6-7 + R.8), crossing a river alone (R.9), renouncing the community and the 3 refuges (R. 13, R. 20).

  Etymologies. TB krāna, possibly plurale tantum, cf. mīsa 'flesh', hence *krānā. Collective shifted to singular in TA. CToch. *kärān-< *krH-n-or levelling of *k H-ōn-, cf. Lat. carō, gen. sg. carnis 'flesh' (de Vaan 2008: 94). < *'piece'. Root *(s)ker-'to cut', etc, basis of Ved. cárman-. TB yetse, TA yats < *yaetsae < * -ot--, cf. Ved. éta-'of varying color, shimmering' (vs. fem. éṇī-, noun eṇ -fem. 'antelope') < * -t-o-. Basis : * -ot-'(shimmering) color' or the like. *H = *h 1 or *h 2 , depending on other comparanda. * Remark about the composition of Tocharian narrative texts: the collage. Inserting pieces of different texts of Sanskrit origin in the main text of the story. Further instances, see the tale of the painter and the mechanical girl (Pinault 2008: 263-268): the comparison of human bodies with puppets; the list of women with whom a wise men should avoid forming any relationship. Recurrent use of lists of notions, of Sanskrit origin, alternatively inspired by Sanskrit or Middle Indic. Pervasive use of clichés and metaphors of Indian origin. § 3. Extract of the Maitreyāvadāna-vyākaraṇa. New reading of A 222 (THT 855), completed with A 239 (THT 872), belonging to 2 different manuscripts (219-238 and 239-242). A 239 overlaps partially with A 222. The end of the leaf 222 finds a decisive parallel in Maitrisimit nom bitig, Turfan (Sängim/Murtuq) recension, chapter XIX, Taf. 57 and 58 (BT IX, I: 160-162), where some details are somewhat more developed, according to habits of the Uighur translators.Meter 4 x 14 syllables: 7 (4+3)/7 (4+3).

(

  nasluneṣi retwe)[a1]ṣi ; kleśāṣi pälkäntwāṣi : praṣtaṣi śkaṃ kāṣāyyo ; spärko pältsä(k) wrasaśśi ( : 102) (cem yäsluṣ yo) naṣuṣ ; omäskeññi wośśi ṣeñc : omäske(näṣ ñañärkuṣ) ; (mā pe wra) [a2] (sa)ñ p u kaṃn atsaṃ : lāñc āmāśāñ ṣoṣtäṅkāñ ; sne-pältikāñ prakṣäntāñ (:) (āpṣātrikāñ ṣukṣeñi) ; kenpar entsuṣ märkampal : 10<3> rapurñe(yo) (cem kaknuṣ) ; [a3] (pärko) kälpä rināntāñ : sne-palṣīnäṃ rīteyo ; rutoṣ wrasa(ñ) (ypeyäntwaṃ) (:) (tmäṣ śa)mma(ṃ)tr-äm opṣlyäntu ; māsäṃśāt-äm want swase : mā cesmi śkaṃ ṣtām-kwreyunt ; [a4] praṣtā pkämṣānt mā käṃṣānt : 104 mā kälymeyā pakkunt cam ; (oko pākär ypamāṃ) ṣtām : spärksā-m pältsäk tmäk särki ; arnaṃ mäs<k>är umparñe : kleśāñ ñätkä(r) ś u k tkā(lune) ; [a5] (nakät ā)ttsek wsokone : skeyasyo pe māski ṣeṣ ; mrosk u lune(yo sākrone : 105) sne-kaś ske ypā pättāṃñkät ; cesäm wrasas mroskässi : aryu praṣtaṃ ṣom (kṣanaṃ ; mā [a6] pe) ontaṃ mrosäṃśānt : camik śpālmeṃ śākyeṣiṃ ; riṣakyāp ṣeṣ nānde ñom (:) (kāwälte yoṃ praca)r ; ṣoma-pācär (riṣa)kyāp : 106 tsopatsäṃ ske spaltäkyo ; tskāt cam (wa)ṣ(täṣ [a7] pättāṃñkät :) k u l(e)yaṃ pältsäk cacräṅku mrosäṅkātsi mā nwiññāt : wāt-äṃ (riṣaksac) ; (a)ntuṣ w(ā)t-ä(ṃ ñäktasac) : wāt-äṃ antuṣ ñareyaṃ : kuppre ontaṃ mroskat säm : (107) (devadatte) [b1] (märkampal) ; āklu ysomo tri-päräs : śaṃkum menāk śäk we pi ; puklā pāṣā(t pāp)ṣūn(e) : ly(ä)m plyask(enaṃ m)usāt säm ; räddhiṣiṃ cam yātlun(e) : ynāñmūneyo yärkantyo ; trīka(ṃ) (pä)ltsä(k) (puk ken[b2]par) (10)8 märkampalṣiṃ läc wäknäṣ ; skāy śkaṃ kossi pättāṃñkät : yāmtsā(t ānantārśäntu) ; klā särki säm aviś ñareyaṃ : gokālik ñom ṣeṣ camik ; waṣtäṣ laltu ā(kälṣäl :) [b3] (casä)s nākäm naṣṣmi säm ; śāris seyā ślak penu : 109 maudgalyāyaṃnā pe śkaṃ ; pram ñkät mättak āltsāt-äṃ : käṣṣī penu pättāṃñkät ; tri-lkwär nunak [ā]ltsāt-äṃ (:) (wäknäṣ mā) säm närkässi [b4] ; antuṣ nwāt klā mahāpadūm : āresāsyo pän kät ṣ(ñ)i ; (käntu pāto) ñareyaṃ : 110 sunakṣatre lyäklyaṃ l(wā) ; malywā yonaṃ (pättāṃñkte : ktoräṣ) [b5] craṅkäs k u cäṣ caṣi ; buddhiśparäṃ kāswone : koluneṣiṃ prayo(kyo) ; (śrigupte ñom waṣt-lmo ṣeṣ) (:) (k)ñāsyo yṣaṃ wāla-ṃ eṣäk wäs ; rarittwā-ṃ św(ā)tsintwaṃ : (111) (aṅgulimāl wra[b6]sas ko)s ; ṣom atsaṃ tmānaṃ wärce : pkāt nuṃ kossi ṣñi mācär ; yeṣäṃn anac pätt(āṃñkät :) (cämpluneyo) tām praṣtaṃ ; stāt nuṃ kossi pättāṃñkät : mā ye(ṣs ākac) (tmäṣṣ ārānt ) ; (säm [b7] pyockä)s ko(c tāk) käṣṣi (: 112) ajātaśatru ñomā ṣeṣ; wäl tām (praṣt) omäsk(eṃ :) (säm kākoräṣ ṣñi pācä)r ; kenpar spārttu pät(t)āṃñktaṃ : yāmt(s)āt sär(k)i (nu deśit) ; -------:

  Broken context: the preceding line ended with yamäṣate. Ogihara 2014: 246. Confrontation with standard lists from Pāli. Paṭisambhidāmagga II, 232: iddhekacco āpokāyaṃ … pe … tejokāyaṃ… vāyokāyaṃ … kesakāyaṃ … lomakāyaṃ … chavikāyaṃ … cammakāyaṃ … maṃsakāyaṃ … rudhirakāyaṃ … nhārukāyaṃ … aṭṭhikāyam … aṭṭhimiñjakāyaṃ aniccato anupassati, no niccato.

	katamā ca, bhikkhave, sīhaseyya? sīho bhikkhave migarājā dakkhiṇena passena seyyaṃ
	kappeti, pāde pādaṃ accādhāya, antarasatthimhi naṅguṭṭhaṃ anupakkhipitvā. so
	paṭibujjhitvā purimaṃ kāyaṃ abbhunnāmetvā pacchimaṃ kāyaṃ anuviloketi. sace,
	bhikkhave, sīho migarājā kiñci passati kāyassa vikkhittaṃ vā visaṭaṃ vā, tena, bhikkhave,
	sīho migarājā anattamano hoti. sace pana, bhikkhave, sīho migarājā na kiñci passati kāyassa
	vikkhittaṃ vā visaṭaṃ vā.
	'And what is the lion's posture? The lion, the king of beasts, lies down on his right side,
	having covered one foot with the other and tucked his tail between his thighs. When he
	awakens, he raises his front quarters and looks back at his hind quarters. If he sees any
	disorderliness or distension of his body, he is displeased. If he does not see any disorderliness
	or distension of his body, he is pleased.'
	Confirmation: lyṣäk*, dual lyäṣkäṃ*, in the locative: 'thigh' = Skt. sakthi-. TB match would
	be *lyaṣke.
	List of further body parts: 11 b6-12 a1 āyäntu śwāl /ysār yats krāṃ yokyo
	12 b2 āyäntu śwāl ysār krāṃ yokyo
	'die Knochen mit Fleisch, Blut, Haut, Fell (?) und Haar' (Schmidt 1974: 95)
	'the bones with flesh, blood, skin, outer skin, and hair' (CEToM)
	TA yats: TB yetse '(outer) skin' (Adams 2013 : 549). = chavi-according to a bilingual ms.
	Plus A 217 b6 wsā-yok yats 'gold-colored skin' = Skt. suvarṇa-cchaviḥ. Cf. Ved. híranya-
	tvac, -tvacas-, same image.
	TA krāṃ '(outer) skin' ( ?) (Carling 2019: 171a). Probably not related to TB krāñi(ye)*
	'neck' (= Skt. manyā-), cf. Adams 2013: 230.
	New possible item: TB krāna, THT 1224 (+ 1213) b1 krāna auloṃ 'k. [and] blood vessels',
	oblique plural.

).

Aṅguttara-nikāya II, 245, transl. Bodhi 2012: 612.

  (SA), part of the Prātimokṣa-sūtra rules. P. saṃghādiseṣa-'a class of offences which can be decided only by a formal conclave' (saṃgha-kamma) (PED: 667b). "wobei derRest [d.h. das Strafmaß] bei der Mönchsgemeinde liegt" (v. Hinüber 1999: 17) BHSD: 549b. 12 for the monks, 19 for the nuns. Skt. saṃghātiśeṣa-(Mahāsāṃghika). Mūlasarvāstivādin : 13 for the monks, 20 for the nuns, cf. Rockhill 1884 (= R.). Prāt., P. lesamattaṃ, quoted BHSD : 463b. Keyword laiśikam 'concerning a trifling thing' (of accusing a monk of a pārājika sin [involving expulsion from the order of monks] on the basis of some trifling matter but afterwards repenting and confessing). N.B. The TA term presupposes the analysis of the compound via MI transmission, hence borrowed (and not re-Sanskritized) *leśä, either enlarged with TA suffix -u (thus transposing Skt. laiśika-) or with ä > u in bilabial context, see late TB forms kaucu-wär, ñoru-wär (PK AS 18B) < *kaucä-, *ñorä-. -mātträr*, with redundant notation in interior position of final syllabic liquid after re-Sanskritization < *māttär/*mātträ < *mātra at word-end, crossed with MI matta. sne-sem: Skt. a-śaraṇa-, P. a-saraṇa-'without refuge' (PED: 697b). ṣmac : allative sg. of ṣäm*, 'remaining' (separate, i.e., from the community), root noun of ṣäm-'to sit, remain'.

	Tentative translation:
	[a1] With treating with homage the Arhat), the venerable one of both communities, I, the so-
	named nun, (I say:) O people! [a2] (If) I have transgressed any prescription pertaining to the
	Saṃghāvaśeṣas, some concealed, some not concealed, (such as) pertaining to lustful
	enjoyment, pertaining to passion [and] making connection for lustful enjoyment, [a3]
	pertaining to disdainful speech, pertaining to injuring of families, pertaining to only trifling
	matter (in accusing monks or nuns), pertaining to being alone amidst day [and] night, [a4]
	pertaining to going alone across a river, pertaining to standing for the suspension without
	refuge, I, the so-named nun, (if) [a5] I have transgressed those prescriptions, belonging to the
	Saṃghāvaśeṣa-sins, some concealed, some not concealed, may I have the pardon from both
	communities!
	Skt. saṃghāvaśeṣa-
	Transcription and restoration of the recto.
	a1	(yärkā yāmluneyaśśäl ārāntāṃ) āṣā(nikāṃ) āmpe pissaṅkäṃtwe • ñuk (tä)ṣne ñomā
		aśi • śoṣi saṅk(ā)vaśeṣäṃtu(ṣi śikṣāpa)t
	a2	(caṃ kätkos tām ṣomaṃ wāwluṃt ṣo)maṃ mā wāwluṃt avasrut tāpluneṣinās
		avasrut tāpluneyaṃ ritwāṣlune-na(ndṣi)nās ā-
	a3	(ppärmāt rakeṣinās ku) ⊗ ladh(v)aṃsaṃṣinās leśu-mātträrṣinās ykoṃ o(ṣeñi)
		ywārśkā snāki n(aslune)ṣī-
	a4 (nās) (snāki wär āsuk) ⊗ kätkāluneṣinās ṣmac ṣtmā(lu)neṣināṣ s(ne)-s(e)m ñuk
		täṣne ño(mā) a(śi) • to-
	a5	(säm śikṣāpatäntu kätkos tām) saṅkāvaśeṣ maṅkäṃtwāśśi • ṣomaṃ wāwluṃt ṣomaṃ
		mā wāwluṃ(tā)śśi • āmpe pissaṅkäṃtwenäṣ (kṣānti tākiṣ-ñi)

Confession formula: TB kṣānti tākoy-ñ, TA k u ṣānti tākiṣ-ñi (230 b4). TA śikṣāpat kätk-: TB śikṣapātänta kätk-.

Loans and calques from Skt. ñuk täṣne ñomā (a1.4): Skt. aham itthaṃnāmā, used in the Karmavācanā. avasrut : Skt. avasruta-(P. avassuta-) 'foul, rotten', here matching rather avaśruta-'sexually lustful' (BHSD: 76a), special use in Vinaya. PED: 84b. tāplune, lit. 'eating' : Skt. bhojana-'enjoyment, sexual intercourse' (BHSD: 412b). P. bhoganand* << Skt. nandī, P. nandī-/nandi-'joy' (BHSD: 280a, PED: 346b). P. nandi-rāga-'pleasure and lust, passionate delight'. ritwāṣlune, cf. Skt. saṃcaritra-, P. saṃcaritta-'procuring, acting as go-between in liaisons' (BHSD: 350a). kuladhvaṃsaṃ* < Skt. kuladhvaṃsana-, re-formulation of kula-dūṣaka-'injurer or spoiler of families' (BHSD : 188a), P. kula-dūsaka-'one who brings a family into bad repute' (PED: 223a). See Nolot 1999: 433-438. leśu-māträr* < < laiśa-mātra-, cf. laiśamātraṃ dharmam,

This publication belongs to the research conducted under the HisTochText project. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 788205).

Handout of a lecture held at Leiden University, Centre for Indo-European Linguistics, December 9, 2020.


Unnimaya Martin Georges Thomas

Thalakkale Veettil

Sylvie Blanc

Thierry Pigot

Susana C M Fernandes

Study of the photostability of bio-inspired biopolymers-conjugated with bioactive molecules in different aquatic environments

niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Study of the photostability of bio-inspired biopolymers-conjugated with bioactive molecules in different aquatic environments

Martin Thomas* 1,2 , Unnimaya Thalakkale Veettil 1,2 , Sylvie Blanc 1 , Thierry Pigot 1 , Susana C. M. Fernandes 1,2,3

1 IPREM, E2S UPPA, Universite de Pau et des Pays de l'Adour, CNRS, 64000 Pau, France 2 MANTA: Marine Materials Research Group, Universite de Pau et des Pays de l'Adour, E2S UPPA, 64600 Anglet, France 3 Polymer Chemistry, Department of Chemistry, Ångström Laboratory, Uppsala University, 751 21 Uppsala, Sweden *email: martin.thomas@univ-pau.fr Lower the devastating impact of the emerging pollutants in the aquatic environments, especially the sunscreen products, is a major challenge in the 21st century. The growing consciousness of the risks associated with skin exposure to ultraviolet (UV) radiation has led to an increased use of sunscreens and, consequently, introduction of new chemical compounds in the marine environment.

Sunscreens present the fastest growing sales globally (7% per year over the last 5 years), associated to the coastal areas population growth and tourism activities [1]. It is thus, particularly challenging to develop safer and innovating UV-absorbing materials derived from biological sources like mycosporine and mycosporine like amino acids [2]. These molecules are photostable, do not generate reactive oxygen species when exposed to UV radiation and have multifunctionality both in terms of therapeutic values (antioxidant ,sunscreen protection and photoprotection attributed to the high molar abosorbivity) and ecological significance (pigment in photosynthesis, intracellular nitrogen storage, etc) [3].

In our research group, we have been mimicking the functionality of some marine organisms to develop photoprotective and environmentally sustainable UV-absorbing compounds and assessing their impact in different aquatic ecosystems. To do so, we are using mycosporine and mycosporine like amino acids extracted from different marine organisms as UV-absorbing bioactive molecules and biopolymers or proteins (chitosan, collagen and hyaluronic acid) to graft these bioactive molecules via chemical coupling ie via amidation [2] and esterfication. In the present communication, we will present our recent study on the photostability of these bioactive molecules and their conjugates that was assessed by emulating the solar radiation conditions using a solar simulator. The photostabillity (abiotic degradation) was studied in pure water and in different natural matrices such as fresh, river, sea and estuary water. The photoproducts post degradation will be also discussed.

1

  Sanchez-Quilles et al, Environment International 83 (2015) 158 2 Fernandes et al, ACS Appl Mater Interfaces 7 (2015) 16558 3 Bhatia et al. Pharmacognosy Reviews, 5(10) (2011) 138.