This review addresses the growing interest for potassium-ion full-cells(KIFCs)in view of the transition from potassium-ion half-cells(KIHCs)toward commercial K-ion batteries(KIBs).It focuses on the key parameters of K...This review addresses the growing interest for potassium-ion full-cells(KIFCs)in view of the transition from potassium-ion half-cells(KIHCs)toward commercial K-ion batteries(KIBs).It focuses on the key parameters of KIFCs such as the electrode/electrolyte interfaces challenge,major barriers,and recent advancements in KIFCs.The strategies for enhancing KIFC performance,including interfaces co ntrol,electrolyte optimization,electrodes capacity ratio,electrode material screening and electrode design,are discussed.The review highlights the need to evaluate KIBs in full-cell configurations as half-cell results are strongly impacted by the K metal reactivity.It also emphasizes the importance of understanding solid electrolyte interphase(SEI)formation in KIFCs and explores promising nonaqueous as well as quasiand all-solid-state electrolytes options.This review thus paves the way for practical,cost-effective,and scalable KIBs as energy storage systems by offering insights and guidance for future research.展开更多
Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless indu...Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless induction heating.By adjusting the reaction conditions,the catalyst is able to perform CO_(2)methanation reaction under autothermal process operated inside a non-adiabatic reactor,without any external energy supply.Such autothermal process is possible thanks to the high apparent density of the UO_x which allows one to confine the reaction heat in a small catalyst volume in order to confine the exothermicity of the reaction inside the catalyst and to operate the reaction at equilibrium heat in-heat out.Such autothermal operation mode allows one to significantly reduce the complexity of the process compared to that operated using adiabatic reactor,where complete insulation is required to prevent heat disequilibrium,in order to reduce as much as possible,the heat exchange with the external medium.The catalyst displays an extremely high stability as a function of time on stream as no apparent deactivation.It is expected that such new catalyst with unprecedented catalytic performance could open new era in the field of heterogeneous catalysis where traditional supports show their limitations to operate catalytic processes under severe reaction conditions.展开更多
In recent years,hard carbon materials have gained significant interest as anode materials for Na-ion batteries.Biomass waste is considered one of the most interesting,renewable,available,and cost-effective precursor t...In recent years,hard carbon materials have gained significant interest as anode materials for Na-ion batteries.Biomass waste is considered one of the most interesting,renewable,available,and cost-effective precursor to obtain hard carbon(HC);however,HC properties must be finely tuned to achieve performance comparable to those provided by Li-ion batteries.In this work,three biomass wastes(coconut shells,walnut shells,and corn silk) were evaluated as potential precursors for HC preparation involving a pyrolysis process and subsequent acid washing to remove the inorganic impurities.All obtained materials exhibited low and similar specific surface areas(<10 m^(2)·g^(-1)), but they presented different structures and surface functionalities.The walnut shell HC possessed a lower amount of inorganic impurities and oxygen-based functional groups compared to the coconut shell and corn silk HCs,leading to higher initial coulombic efficiency(iCE).The structural organization was higher in the case of the walnut shell HC,while the corn silk HC revealed a heterogeneous structure combining both highly disordered carbon and localized graphitized domains.All HCs delivered high initial reversible capacities between 293 and 315 mAh g^(-1) at 50 mA g^(-1) current rate,which remained rather stable during long-term cycling.The best capacity(293 mAh g^(-1) after 100 charge/discharge cycles) and highest capacity retention(93%) was achieved in walnut HCs in half-cells,which could be associated with its higher sp2 C content,better organized structure,and fewer impurities.An "adsorption-insertion" Na storage mechanism is suggested based on several techniques.The walnut HCs exhibited an attractive energy density of 279 Wh/kg when tested in full cells.展开更多
In a context of a virus that is transmissive by sputtering,wearing masks appear necessary to protect the wearer and to limit the propagation of the disease.Currently,we are facing the 2019-2020 coronavirus pandemic.Co...In a context of a virus that is transmissive by sputtering,wearing masks appear necessary to protect the wearer and to limit the propagation of the disease.Currently,we are facing the 2019-2020 coronavirus pandemic.Coronavirus disease 2019(COVID-19)is an infectious disease with first symptoms similar to the flu.The symptom of COVID-19 was reported first in China and very quickly spreads to the rest of the world.The COVID-19 contagiousness is known to be high by comparison with the flu.In this paper,we propose a design of a mobile application for permitting everyone having a smartphone and being able to take a picture to verify that his/her protection mask is correctly positioned on his/her face.Such application can be particularly useful for people using face protection mask for the first time and notably for children and old people.The designed method exploits Haar-like feature descriptors to detect key features of the face and a decision-making algorithm is applied.Experimental results show the potential of this method in the validation of the correct mask wearing.To the best of our knowledge,our work is the only one that currently proposes a mobile application design“CheckYourMask”for validating the correct wearing of protection mask.展开更多
One option to fight global warming is to convert our use of fossil energy into renewables such as biomass energy.However,the forest preservation and the quality of the ambient air are also two major issues.Therefore,t...One option to fight global warming is to convert our use of fossil energy into renewables such as biomass energy.However,the forest preservation and the quality of the ambient air are also two major issues.Therefore,the use of biomass waste without any supplementary emissions could represent a part of the solution.In this study,two fuels were considered for a 200 kW moving grate boiler.A multicyclone and a bag filter were fitted on the boiler.The first fuel consisted of classical wood chips whereas the second was a mixture of wood chips with sewage sludge.This second fuel presented a high ashes mass ratio compared to wood chips.The aim was to verify the possibility to burn this kind of fuel without any modification of the installation.The first relevant result is that the conventional pollutants,i.e.,CO and NOx,remained under the emissions limits even with the sewage sludge combustion.The Total Suspended Particles emissions at the exhaust were always under 5.4 mg·Nm-3 dry based corrected at 6%of O_(2),which is low with respect to the standard limitation.The majority of the ashes remained on the combustion room.However,with both fuels,about 5%of ashes mass remained in the heat exchanger.Nevertheless,the heat exchanger was more clogged with the second fuel,which produced five time more ashes.This may lead to a yield loss.Thus,sewage sludge can be used in a wood boiler without any issue if an automatic exchanger sweep is fitted on the installation.展开更多
Porous metal-based carbon nanocomposites,with a monolithic shape,were prepared by a one-pot synthesis from dissolved cellulose and metallic salts using a simple,cheap,and environmentally friendly route.Their potential...Porous metal-based carbon nanocomposites,with a monolithic shape,were prepared by a one-pot synthesis from dissolved cellulose and metallic salts using a simple,cheap,and environmentally friendly route.Their potential performances as electrochemical capacitors were tested with three metal precursors(M=Cu,Mn,and Fe)with two loadings and in an asymmetric cell for the Fe-based carbon material.Interestingly,here soluble metal precursors were not deposited on a hard cellulose template but mixed in a precooled concentrated NaOH solution where cellulose was previously dissolved,allowing for a good dispersion of the metallic species.After a freezing step where concomitant cellulose regeneration and pore ice-templating phenomena took place,followed by a carbonization step,the mixture led to a porous carbon monolith embedding well-dispersed metal-based nanoparticles having a diameter below 20 nm and present as metallic,oxide,or carbide phase(s)according to the element M.These materials were characterized by different physicochemical techniques and electrochemical tests.Their performances as supercapacitors are discussed in light of the specific behaviour of the metal-based phase and its influence on the carbon matrix properties such as mesopore formation and carbon graphitization.An asymmetric energy storage cell assembled with a Fe-based carbon electrode against a carbon xerogel electrode derived from a phenolic resin shows specific energy and power of 18.3 Wh kg^(−1)at 5 mA cm^(−2)and 1.6 kW kg^(−1)at 25 mA cm^(−2),respectively.展开更多
3D printing technologies have expanded beyond the research laboratories where they were used solely for prototyping and have become widely used in several industries.The production of custom 3D objects has significant...3D printing technologies have expanded beyond the research laboratories where they were used solely for prototyping and have become widely used in several industries.The production of custom 3D objects has significant potential in optical applications.However,this necessitates extremely specific material properties,such as transparency,homogeneity,birefringence,and surface finish.Currently,the majority of optical objects are manufactured using plastics.Moreover,the 3D printing processes using polymers to produce optical objects have significant advantages,such as limited wastage,short manufacturing time,and easy customization.However,despite extensive efforts,no technology has achieved the production of objects perfectly suited for optical applications.The objective of this review is to summarize recent advances in the field of 3D printing for optics,with an emphasis on specific developments for dedicated applications,and to explore new candidate processes.展开更多
A series of D-π-A type sulfonium salt photoacid generators with different π-conjugated structures, such as triphenyl, phenylstilbene, styryl-biphenyl, and stilbene, were designed to determine the effect of molecular...A series of D-π-A type sulfonium salt photoacid generators with different π-conjugated structures, such as triphenyl, phenylstilbene, styryl-biphenyl, and stilbene, were designed to determine the effect of molecular structures on the photochemical and photophysical properties. The mechanisms of photochemical generation of H＋ were studied by UV-Vis spectroscopy, theoretical calculations, and fluorescence spectroscopy. It is found that the frontier orbits determine the absorption, the molar extinction coefficients, and the quantum yields of photoacid generation. Triphenyl systems connected with sulfonium are beneficial to increase the quantum yields of acid generation. The photoreactivity of four sulfonium salts was further evaluated through the polymerizations of various epoxide monomers at different irradiation wavelengths （365- 425 nm） by using the real-time infrared spectroscopy with light-emitting diodes. The high quantum yields for acid generation （ФH＋ = -0.32 to 0.58） and the high molar extinction coefficients （ε = -23500 L.mol-1.cm-1 to 31000 L.mol-1.cm-1） of the sulfonium salts lead to high conversion rates （over 50%-80%）. Hence, these photoinitiators exhibit potential for the photocuring applications.展开更多
基金supported by the Agence Nationale de la Recherche,France(ANR)through the TROPIC project(ANR-19CE05-0026)。
文摘This review addresses the growing interest for potassium-ion full-cells(KIFCs)in view of the transition from potassium-ion half-cells(KIHCs)toward commercial K-ion batteries(KIBs).It focuses on the key parameters of KIFCs such as the electrode/electrolyte interfaces challenge,major barriers,and recent advancements in KIFCs.The strategies for enhancing KIFC performance,including interfaces co ntrol,electrolyte optimization,electrodes capacity ratio,electrode material screening and electrode design,are discussed.The review highlights the need to evaluate KIBs in full-cell configurations as half-cell results are strongly impacted by the K metal reactivity.It also emphasizes the importance of understanding solid electrolyte interphase(SEI)formation in KIFCs and explores promising nonaqueous as well as quasiand all-solid-state electrolytes options.This review thus paves the way for practical,cost-effective,and scalable KIBs as energy storage systems by offering insights and guidance for future research.
基金ORANO Chimie-Enrichissement Co.for the financial support of this project。
文摘Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless induction heating.By adjusting the reaction conditions,the catalyst is able to perform CO_(2)methanation reaction under autothermal process operated inside a non-adiabatic reactor,without any external energy supply.Such autothermal process is possible thanks to the high apparent density of the UO_x which allows one to confine the reaction heat in a small catalyst volume in order to confine the exothermicity of the reaction inside the catalyst and to operate the reaction at equilibrium heat in-heat out.Such autothermal operation mode allows one to significantly reduce the complexity of the process compared to that operated using adiabatic reactor,where complete insulation is required to prevent heat disequilibrium,in order to reduce as much as possible,the heat exchange with the external medium.The catalyst displays an extremely high stability as a function of time on stream as no apparent deactivation.It is expected that such new catalyst with unprecedented catalytic performance could open new era in the field of heterogeneous catalysis where traditional supports show their limitations to operate catalytic processes under severe reaction conditions.
基金financial support from the European Union’s Horizon2020 Program(project NAIADEScall:LCE10-2014,Contract no.646433)。
文摘In recent years,hard carbon materials have gained significant interest as anode materials for Na-ion batteries.Biomass waste is considered one of the most interesting,renewable,available,and cost-effective precursor to obtain hard carbon(HC);however,HC properties must be finely tuned to achieve performance comparable to those provided by Li-ion batteries.In this work,three biomass wastes(coconut shells,walnut shells,and corn silk) were evaluated as potential precursors for HC preparation involving a pyrolysis process and subsequent acid washing to remove the inorganic impurities.All obtained materials exhibited low and similar specific surface areas(<10 m^(2)·g^(-1)), but they presented different structures and surface functionalities.The walnut shell HC possessed a lower amount of inorganic impurities and oxygen-based functional groups compared to the coconut shell and corn silk HCs,leading to higher initial coulombic efficiency(iCE).The structural organization was higher in the case of the walnut shell HC,while the corn silk HC revealed a heterogeneous structure combining both highly disordered carbon and localized graphitized domains.All HCs delivered high initial reversible capacities between 293 and 315 mAh g^(-1) at 50 mA g^(-1) current rate,which remained rather stable during long-term cycling.The best capacity(293 mAh g^(-1) after 100 charge/discharge cycles) and highest capacity retention(93%) was achieved in walnut HCs in half-cells,which could be associated with its higher sp2 C content,better organized structure,and fewer impurities.An "adsorption-insertion" Na storage mechanism is suggested based on several techniques.The walnut HCs exhibited an attractive energy density of 279 Wh/kg when tested in full cells.
文摘In a context of a virus that is transmissive by sputtering,wearing masks appear necessary to protect the wearer and to limit the propagation of the disease.Currently,we are facing the 2019-2020 coronavirus pandemic.Coronavirus disease 2019(COVID-19)is an infectious disease with first symptoms similar to the flu.The symptom of COVID-19 was reported first in China and very quickly spreads to the rest of the world.The COVID-19 contagiousness is known to be high by comparison with the flu.In this paper,we propose a design of a mobile application for permitting everyone having a smartphone and being able to take a picture to verify that his/her protection mask is correctly positioned on his/her face.Such application can be particularly useful for people using face protection mask for the first time and notably for children and old people.The designed method exploits Haar-like feature descriptors to detect key features of the face and a decision-making algorithm is applied.Experimental results show the potential of this method in the validation of the correct mask wearing.To the best of our knowledge,our work is the only one that currently proposes a mobile application design“CheckYourMask”for validating the correct wearing of protection mask.
基金This study was realized thanks to the financial support of ADEME and the financial and technical support of LERMAB,especially the ERBE platform.LERMAB is supported by a grant over seen by the French National Research Agency(ANR)as part of the“Investissements d’Avenir”Program(ANR-11-LABX-0002-01.Lab of Excellence ARBRE)and is part of ICEEL.
文摘One option to fight global warming is to convert our use of fossil energy into renewables such as biomass energy.However,the forest preservation and the quality of the ambient air are also two major issues.Therefore,the use of biomass waste without any supplementary emissions could represent a part of the solution.In this study,two fuels were considered for a 200 kW moving grate boiler.A multicyclone and a bag filter were fitted on the boiler.The first fuel consisted of classical wood chips whereas the second was a mixture of wood chips with sewage sludge.This second fuel presented a high ashes mass ratio compared to wood chips.The aim was to verify the possibility to burn this kind of fuel without any modification of the installation.The first relevant result is that the conventional pollutants,i.e.,CO and NOx,remained under the emissions limits even with the sewage sludge combustion.The Total Suspended Particles emissions at the exhaust were always under 5.4 mg·Nm-3 dry based corrected at 6%of O_(2),which is low with respect to the standard limitation.The majority of the ashes remained on the combustion room.However,with both fuels,about 5%of ashes mass remained in the heat exchanger.Nevertheless,the heat exchanger was more clogged with the second fuel,which produced five time more ashes.This may lead to a yield loss.Thus,sewage sludge can be used in a wood boiler without any issue if an automatic exchanger sweep is fitted on the installation.
文摘Porous metal-based carbon nanocomposites,with a monolithic shape,were prepared by a one-pot synthesis from dissolved cellulose and metallic salts using a simple,cheap,and environmentally friendly route.Their potential performances as electrochemical capacitors were tested with three metal precursors(M=Cu,Mn,and Fe)with two loadings and in an asymmetric cell for the Fe-based carbon material.Interestingly,here soluble metal precursors were not deposited on a hard cellulose template but mixed in a precooled concentrated NaOH solution where cellulose was previously dissolved,allowing for a good dispersion of the metallic species.After a freezing step where concomitant cellulose regeneration and pore ice-templating phenomena took place,followed by a carbonization step,the mixture led to a porous carbon monolith embedding well-dispersed metal-based nanoparticles having a diameter below 20 nm and present as metallic,oxide,or carbide phase(s)according to the element M.These materials were characterized by different physicochemical techniques and electrochemical tests.Their performances as supercapacitors are discussed in light of the specific behaviour of the metal-based phase and its influence on the carbon matrix properties such as mesopore formation and carbon graphitization.An asymmetric energy storage cell assembled with a Fe-based carbon electrode against a carbon xerogel electrode derived from a phenolic resin shows specific energy and power of 18.3 Wh kg^(−1)at 5 mA cm^(−2)and 1.6 kW kg^(−1)at 25 mA cm^(−2),respectively.
文摘3D printing technologies have expanded beyond the research laboratories where they were used solely for prototyping and have become widely used in several industries.The production of custom 3D objects has significant potential in optical applications.However,this necessitates extremely specific material properties,such as transparency,homogeneity,birefringence,and surface finish.Currently,the majority of optical objects are manufactured using plastics.Moreover,the 3D printing processes using polymers to produce optical objects have significant advantages,such as limited wastage,short manufacturing time,and easy customization.However,despite extensive efforts,no technology has achieved the production of objects perfectly suited for optical applications.The objective of this review is to summarize recent advances in the field of 3D printing for optics,with an emphasis on specific developments for dedicated applications,and to explore new candidate processes.
基金financially supported by the National Natural Science Foundation of China(Nos.51173134 and 51573139)Fundamental Research Funds for the Central Universities and the Open Measuring Fund for Large Instrument and Equipment(No.0002015033)of Tongji University
文摘A series of D-π-A type sulfonium salt photoacid generators with different π-conjugated structures, such as triphenyl, phenylstilbene, styryl-biphenyl, and stilbene, were designed to determine the effect of molecular structures on the photochemical and photophysical properties. The mechanisms of photochemical generation of H＋ were studied by UV-Vis spectroscopy, theoretical calculations, and fluorescence spectroscopy. It is found that the frontier orbits determine the absorption, the molar extinction coefficients, and the quantum yields of photoacid generation. Triphenyl systems connected with sulfonium are beneficial to increase the quantum yields of acid generation. The photoreactivity of four sulfonium salts was further evaluated through the polymerizations of various epoxide monomers at different irradiation wavelengths （365- 425 nm） by using the real-time infrared spectroscopy with light-emitting diodes. The high quantum yields for acid generation （ФH＋ = -0.32 to 0.58） and the high molar extinction coefficients （ε = -23500 L.mol-1.cm-1 to 31000 L.mol-1.cm-1） of the sulfonium salts lead to high conversion rates （over 50%-80%）. Hence, these photoinitiators exhibit potential for the photocuring applications.
