The use of carbon from waste biomass has the potential to eliminate the drawbacks of Li-S batteries and improve their overall performance.Chrome-tanned-leather-shavings(CTLS)are a readily available waste product that ...The use of carbon from waste biomass has the potential to eliminate the drawbacks of Li-S batteries and improve their overall performance.Chrome-tanned-leather-shavings(CTLS)are a readily available waste product that can be transformed into porous carbon.We prepared an ac-tivated carbon by microwave pyrolysis combined with KOH activator using the CTLS as starting materials.The carbon had a specific surface area of 556 m^(2)g^(-1) and a honeycomb-like structure.Two kinds of N-doped activated carbons were then synthesized by thermal decomposition of the activated carbon,either combined with urea,or impregnated with eth-anolamine.Both N-doped activated carbons have an in-creased number of nitrogen and amine surface groups.However,only the urea treatment was effective in improv-ing the initial capacity of the cell(1363 mAh g^(-1)),which is probably linked to the sorption of long-chain polysulfides.This investigation confirms that it is possible to use the thermal de-composition of urea to obtain carbon materials from CTLS for use as the sulfur-host cathode in Li-S batteries and improve their performance.A radial basis function neural network was fitted to provide statistical support for the experimental results,which confirmed the importance of the nitrogen content of the carbons in determining the discharge capacity of the cells.展开更多
In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon ...In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content.展开更多
Chemical warfare agents(CWAs)are extremely lethal substances used in warfare and terrorism,capable of causing permanent damage even in small doses,despite medical intervention.Therefore,detection,protection,and detoxi...Chemical warfare agents(CWAs)are extremely lethal substances used in warfare and terrorism,capable of causing permanent damage even in small doses,despite medical intervention.Therefore,detection,protection,and detoxification of CWAs are vital for the safety of first responders,military personnel,and civilians,driving significant research in this area.Herein,we designed and synthesized a poly(-diallyldimethylammonium chloride)(PDDA)mediated cupric oxide(CuO)functionalized activated carbon fabric(ACF),termed ACF@PDDA-CuO,as an adsorbent filter material for self-detoxifying chemical protective clothing.PDDA,a positively charged polyelectrolyte,effectively binds in-situ synthesized CuO to the negatively charged ACF surface,serving as a suitable binder.This study demonstrates the synergistic effects of PDDA-CuO functionalization on ACF,where PDDA treatment enhanced mechanical and comfort properties,and CuO crystal growth significantly improved detoxification efficacy against the CWA Nerve Agent Sarin.Comprehensive analyses,including FTIR,BET surface area analysis,SEM,EDS,TEM,STEM,TGA,XPS,and XRD,confirmed the uniform deposition of CuO and PDDA on the ACF surface.The Cu content on ACF@PDDA-CuO samples was measured via iodometric titration.The materials were evaluated for tensile strength,air permeability,water vapor permeability,nerve agent(Sarin)detoxification,and blister agent(Sulfur Mustard)breakthrough time to assess their applicability for protective clothing.The optimized PDDA-CuO on ACF detoxified 82.04%of Sarin within 18 h,compared to 25.22%by ACF alone,and enhanced tensile strength by 23.67%,air permeability by 24.63%,and water vapor permeability by 3.94%,while maintaining protection against Sulfur Mustard for 24 h.These findings indicate that ACF@PDDA-CuO is a promising candidate for CWA protective clothing,offering robust protection with enhanced comfort.展开更多
单级式双有源桥(dual active bridge,DAB)DC/AC变换器控制自由度多,变压器匝比、漏感、开关频率等参数相互耦合,导致变换器效率优化面临多重制约。该文分析变压器匝比、漏感与软开关范围、漏感电流有效值、漏感电流峰值之间的约束关系,...单级式双有源桥(dual active bridge,DAB)DC/AC变换器控制自由度多,变压器匝比、漏感、开关频率等参数相互耦合,导致变换器效率优化面临多重制约。该文分析变压器匝比、漏感与软开关范围、漏感电流有效值、漏感电流峰值之间的约束关系,提出直接表征DAB-DC/AC变换器效率的物理量:效率敏感因子。通过研究效率敏感因子对系统损耗的影响机理,实现变换器效率最优的硬件参数设计,为多参数耦合的单级式DAB-DC/AC变换器效率优化提供理论指导。最后通过一台450 W样机验证所提理论的正确性。展开更多
There has recently been a fundamental need to develop high efficiency microwave absorbers to reduce electro-magnet-ic pollution.It is often very difficult to obtain superior absorption with only one material,so we hav...There has recently been a fundamental need to develop high efficiency microwave absorbers to reduce electro-magnet-ic pollution.It is often very difficult to obtain superior absorption with only one material,so we have explored composites using fillers of activated carbon derived from biological material(oleaster seeds)and resin(apricot tree gum)with Fe_(3)O_(4) in a paraffin wax matrix to improve the dielectric properties and achieve a high specific surface area.A 1 mm thick layer of a Fe_(3)O_(4)+resin(FEOR),with the magnetic nanoparticles anchored to the gum,resulted in a reflection loss of−71.09 dB.We compared this with the results for composites using a filler of Fe_(3)O_(4)+activated carbon,and one with a three-component filler of Fe_(3)O_(4)+activated carbon+resin which had a very porous structure that had a direct effect on the surface polarization.However,the FEOR sample had near-ideal im-pedance matching,close to 1,which resulted in high absorption performance.In addition,the presence of defects improves mi-crowave attenuation by dipole polarization and charge carrier trapping.This work suggests the use of new types of biomaterials to in-crease microwave absorption.展开更多
Mesoporous carbon supports mitigate platinum(Pt)sulfonic poisoning through nanopore-confined Pt deposition,yet their morphological impacts on oxygen transport remain unclear.This study integrates carbon support morpho...Mesoporous carbon supports mitigate platinum(Pt)sulfonic poisoning through nanopore-confined Pt deposition,yet their morphological impacts on oxygen transport remain unclear.This study integrates carbon support morphology simulation with an enhanced agglomerate model to establish a mathematical framework elucidating pore evolution,Pt utilization,and oxygen transport in catalyst layers.Results demonstrate dominant local mass transport resistance governed by three factors:(1)active site density dictating oxygen flux;(2)ionomer film thickness defining shortest transport path;(3)ionomer-to-Pt surface area ratio modulating practical pathway length.At low ionomer-to-carbon(I/C)ratios,limited active sites elevate resistance(Factor 1 dominant).Higher I/C ratios improve the ionomer coverage but eventually thicken ionomer films,degrading transport(Factors 2–3 dominant).The results indicate that larger carbon particles result in a net increase in local transport resistance by reducing external surface area and increasing ionomer thickness.As the proportion of Pt situated in nanopores or the Pt mass fraction increases,elevated Pt density inside the nanopores exacerbates pore blockage.This leads to the increased transport resistance by reducing active sites,and increasing ionomer thickness and surface area.Lower Pt loading linearly intensifies oxygen flux resistance.The model underscores the necessity to optimize support morphology,Pt distribution,and ionomer content to prevent pore blockage while balancing catalytic activity and transport efficiency.These insights provide a systematic approach for designing high-performance mesoporous carbon catalysts.展开更多
A five steps pressure swing adsorption process was designed for acetone and toluene mixtures separation and recovery. Dynamic distributions of gas phase content and temperature were investigated. Based on the theory o...A five steps pressure swing adsorption process was designed for acetone and toluene mixtures separation and recovery. Dynamic distributions of gas phase content and temperature were investigated. Based on the theory of Soret and Dufour, a non-isothermal mathematical model was developed to simulate the PSA process. Effects of heat and mass transfer coefficients were studied. The coupled Soret and Dufour effects were also evaluated. It is found that the heat transfer coefficient has little effect on mass transfer in adsorption stage. However, it has some impacts in desorption stage. The maximum value of C/C0 increases by about 25% as heat transfer coefficient decreases. The temperature variation is less than 0.05 K with the change of mass transfer coefficient, so that the effect of mass transfer coefficient on heat transfer can be ignored. It is also concluded that the Soret and Dufour coupled effects are not obvious in pressure swing adsorption compared with fixed-bed adsorption.展开更多
文摘The use of carbon from waste biomass has the potential to eliminate the drawbacks of Li-S batteries and improve their overall performance.Chrome-tanned-leather-shavings(CTLS)are a readily available waste product that can be transformed into porous carbon.We prepared an ac-tivated carbon by microwave pyrolysis combined with KOH activator using the CTLS as starting materials.The carbon had a specific surface area of 556 m^(2)g^(-1) and a honeycomb-like structure.Two kinds of N-doped activated carbons were then synthesized by thermal decomposition of the activated carbon,either combined with urea,or impregnated with eth-anolamine.Both N-doped activated carbons have an in-creased number of nitrogen and amine surface groups.However,only the urea treatment was effective in improv-ing the initial capacity of the cell(1363 mAh g^(-1)),which is probably linked to the sorption of long-chain polysulfides.This investigation confirms that it is possible to use the thermal de-composition of urea to obtain carbon materials from CTLS for use as the sulfur-host cathode in Li-S batteries and improve their performance.A radial basis function neural network was fitted to provide statistical support for the experimental results,which confirmed the importance of the nitrogen content of the carbons in determining the discharge capacity of the cells.
基金Supported by the Special Fund for Agro-scientific Research in Public Interest in China(201503119-06-01)。
文摘In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content.
基金Defence Research and Development Establishment(DRDE),DRDO,Gwalior-474002,(India)for his keen interestencouragement.The DRDE accession number for this manuscript is DRDE-IREC-130-28/03/2024.
文摘Chemical warfare agents(CWAs)are extremely lethal substances used in warfare and terrorism,capable of causing permanent damage even in small doses,despite medical intervention.Therefore,detection,protection,and detoxification of CWAs are vital for the safety of first responders,military personnel,and civilians,driving significant research in this area.Herein,we designed and synthesized a poly(-diallyldimethylammonium chloride)(PDDA)mediated cupric oxide(CuO)functionalized activated carbon fabric(ACF),termed ACF@PDDA-CuO,as an adsorbent filter material for self-detoxifying chemical protective clothing.PDDA,a positively charged polyelectrolyte,effectively binds in-situ synthesized CuO to the negatively charged ACF surface,serving as a suitable binder.This study demonstrates the synergistic effects of PDDA-CuO functionalization on ACF,where PDDA treatment enhanced mechanical and comfort properties,and CuO crystal growth significantly improved detoxification efficacy against the CWA Nerve Agent Sarin.Comprehensive analyses,including FTIR,BET surface area analysis,SEM,EDS,TEM,STEM,TGA,XPS,and XRD,confirmed the uniform deposition of CuO and PDDA on the ACF surface.The Cu content on ACF@PDDA-CuO samples was measured via iodometric titration.The materials were evaluated for tensile strength,air permeability,water vapor permeability,nerve agent(Sarin)detoxification,and blister agent(Sulfur Mustard)breakthrough time to assess their applicability for protective clothing.The optimized PDDA-CuO on ACF detoxified 82.04%of Sarin within 18 h,compared to 25.22%by ACF alone,and enhanced tensile strength by 23.67%,air permeability by 24.63%,and water vapor permeability by 3.94%,while maintaining protection against Sulfur Mustard for 24 h.These findings indicate that ACF@PDDA-CuO is a promising candidate for CWA protective clothing,offering robust protection with enhanced comfort.
文摘单级式双有源桥(dual active bridge,DAB)DC/AC变换器控制自由度多,变压器匝比、漏感、开关频率等参数相互耦合,导致变换器效率优化面临多重制约。该文分析变压器匝比、漏感与软开关范围、漏感电流有效值、漏感电流峰值之间的约束关系,提出直接表征DAB-DC/AC变换器效率的物理量:效率敏感因子。通过研究效率敏感因子对系统损耗的影响机理,实现变换器效率最优的硬件参数设计,为多参数耦合的单级式DAB-DC/AC变换器效率优化提供理论指导。最后通过一台450 W样机验证所提理论的正确性。
基金funding from Stiftelsen Olle Engkvist Byggmastare(214-0346 and 217-0014)the Swedish Research Council(202103675)。
文摘There has recently been a fundamental need to develop high efficiency microwave absorbers to reduce electro-magnet-ic pollution.It is often very difficult to obtain superior absorption with only one material,so we have explored composites using fillers of activated carbon derived from biological material(oleaster seeds)and resin(apricot tree gum)with Fe_(3)O_(4) in a paraffin wax matrix to improve the dielectric properties and achieve a high specific surface area.A 1 mm thick layer of a Fe_(3)O_(4)+resin(FEOR),with the magnetic nanoparticles anchored to the gum,resulted in a reflection loss of−71.09 dB.We compared this with the results for composites using a filler of Fe_(3)O_(4)+activated carbon,and one with a three-component filler of Fe_(3)O_(4)+activated carbon+resin which had a very porous structure that had a direct effect on the surface polarization.However,the FEOR sample had near-ideal im-pedance matching,close to 1,which resulted in high absorption performance.In addition,the presence of defects improves mi-crowave attenuation by dipole polarization and charge carrier trapping.This work suggests the use of new types of biomaterials to in-crease microwave absorption.
基金supported by the Program of Ministry of Science and Technology of China(No.2023YFB2504200)support of Shanghai Rising-Star Program(Grant No.24QB2703200)the Major Science and Technology Projects of Yunnan Province(No.202302AH360001).
文摘Mesoporous carbon supports mitigate platinum(Pt)sulfonic poisoning through nanopore-confined Pt deposition,yet their morphological impacts on oxygen transport remain unclear.This study integrates carbon support morphology simulation with an enhanced agglomerate model to establish a mathematical framework elucidating pore evolution,Pt utilization,and oxygen transport in catalyst layers.Results demonstrate dominant local mass transport resistance governed by three factors:(1)active site density dictating oxygen flux;(2)ionomer film thickness defining shortest transport path;(3)ionomer-to-Pt surface area ratio modulating practical pathway length.At low ionomer-to-carbon(I/C)ratios,limited active sites elevate resistance(Factor 1 dominant).Higher I/C ratios improve the ionomer coverage but eventually thicken ionomer films,degrading transport(Factors 2–3 dominant).The results indicate that larger carbon particles result in a net increase in local transport resistance by reducing external surface area and increasing ionomer thickness.As the proportion of Pt situated in nanopores or the Pt mass fraction increases,elevated Pt density inside the nanopores exacerbates pore blockage.This leads to the increased transport resistance by reducing active sites,and increasing ionomer thickness and surface area.Lower Pt loading linearly intensifies oxygen flux resistance.The model underscores the necessity to optimize support morphology,Pt distribution,and ionomer content to prevent pore blockage while balancing catalytic activity and transport efficiency.These insights provide a systematic approach for designing high-performance mesoporous carbon catalysts.
基金Projects(20976200,20676154) supported by the National Natural Science Foundation of China
文摘A five steps pressure swing adsorption process was designed for acetone and toluene mixtures separation and recovery. Dynamic distributions of gas phase content and temperature were investigated. Based on the theory of Soret and Dufour, a non-isothermal mathematical model was developed to simulate the PSA process. Effects of heat and mass transfer coefficients were studied. The coupled Soret and Dufour effects were also evaluated. It is found that the heat transfer coefficient has little effect on mass transfer in adsorption stage. However, it has some impacts in desorption stage. The maximum value of C/C0 increases by about 25% as heat transfer coefficient decreases. The temperature variation is less than 0.05 K with the change of mass transfer coefficient, so that the effect of mass transfer coefficient on heat transfer can be ignored. It is also concluded that the Soret and Dufour coupled effects are not obvious in pressure swing adsorption compared with fixed-bed adsorption.
