Zn content is one of the most concerned factors in the development of next generation ultra-strength Al-Zn-Mg-Cu alloys owing to its essential role in precipitation strengthening.In the present work,the underlying fun...Zn content is one of the most concerned factors in the development of next generation ultra-strength Al-Zn-Mg-Cu alloys owing to its essential role in precipitation strengthening.In the present work,the underlying functions of Zn content in precipitation evolution and strengthening function of Al-Zn-Mg-Cu alloys were systematically investigated by combining multiple experiments and an integrated internalstate-variable model.The experimental results indicated that the increased Zn content in Al-Zn-Mg-Cu alloys would promote the development of precipitates and enhance aging hardening.The diffusion flux of soluble Zn and the coordination of Mg atom controlled the crystallographic microstructures evolution during precipitates nucleation,growth and transition processes.By integrating precipitation development with electrical resistivity and hardness evolutions,an improved internal-state-variable physical model was then developed for the aging responses of Al-Zn-Mg-Cu alloys.The unified model considered the intrinsic characteristics of precipitates such as crystallographic orientation,morphology,component,and distribution.The specific improvements were to balance the combined functions of Zn element and Mg element and consider the plate-like morphology and directed growth as indicated by experiments.This model was also adaptive to heat-treatment variables and chemical compositions,and owned the notable advantages to simultaneously rationalize the observed microstructural characteristics,mechanical and electrical properties following artificial aging of Al-Zn-Mg-Cu alloys.In addition,a preliminary model framework between electrical resistivity and hardness for Al-Zn-Mg-Cu alloys was established.展开更多
A type of calcium coke was developed for use in the oxy-thermal process of calcium carbide production.The calcium coke was prepared by the co-pyrolysis of coking coal and calcium carbide slag, which is a solid waste g...A type of calcium coke was developed for use in the oxy-thermal process of calcium carbide production.The calcium coke was prepared by the co-pyrolysis of coking coal and calcium carbide slag, which is a solid waste generated from the chlor-alkali industry.The characteristics of the calcium cokes under different conditions were analyzed experimentally and theoretically.The results show that the thermal strength of calcium coke increased with the increase in the coking coal proportion, and the waterproof property of calcium coke also increased with increased carbonation time.The calcium coke can increase the contact area of calcium and carbon in the calcium carbide production process.Furthermore, the pore structure of the calcium coke can enhance the diffusion of gas inside the furnace, thus improving the efficiency of the oxy-thermal technology.展开更多
The heat capacity of ionic liquids is an important physical property,and experimental measuring is usually used as a common method to obtain them.Owing to the huge number of ionic liquids that can be potentially synth...The heat capacity of ionic liquids is an important physical property,and experimental measuring is usually used as a common method to obtain them.Owing to the huge number of ionic liquids that can be potentially synthesized,it is desirable to acquire theoretical predictions.In this work,the Conductor-like Screening Model for Real Solvents(COSMO-RS)was used to predict the heat capacity of pure ionic liquids,and an intensive literature survey was conducted for providing a database to verify the prediction of COSMO-RS.The survey shows that the heat capacity is available for 117 ionic liquids at temperatures ranging 77.66-520 K since 2004,and the 4025 data points in total with the values from 76.37 to 1484 J·mol^(-1)·K^(-1) have been reported.The prediction of heat capacity with COSMO-RS can only be conducted at two temperatures(298 and 323 K).The comparison with the experimental data proves the prediction reliability of COSMO-RS,and the average relative deviation(ARD)is 8.54%.Based on the predictions at two temperatures,a linear equation was obtained for each ionic liquid,and the heat capacities at other temperatures were then estimated via interpolation and extrapolation.The acquired heat capacities at other temperatures were then compared with the experimental data,and the ARD is only 9.50%.This evidences that the heat capacity of a pure ionic liquid follows a linear equation within the temperature range of study,and COSMO-RS can be used to predict the heat capacity of ionic liquids reliably.展开更多
The CO_(2)solubilities(including CO_(2)Henry’s constant)in physical-and chemical-based ILs/DESs and the COSMO-RS models describing these properties were comprehensively collected and summarized.The summarized results...The CO_(2)solubilities(including CO_(2)Henry’s constant)in physical-and chemical-based ILs/DESs and the COSMO-RS models describing these properties were comprehensively collected and summarized.The summarized results indicate that chemical-based ILs/DESs are superior to physical-based ILs/DESs for CO_(2)capture,especially those ILs have functionalized cation and anion,and superbase DESs;some of the superbase DESs have higher CO_(2)solubilities than those of ILs;the best physical-and chemical-based ILs,as well as physical-and chemicalbased DESs are[BMIM][BF4](4.20 mol kg^(-1)),[DETAH][Im](11.91 mol kg^(-1)),[L-Arg]-Gly 1:6(4.92 mol kg^(-1))and TBD-EG 1:4(12.90 mol kg^(-1)),respectively.Besides the original COSMO-RS mainly providing qualitative predictions,six corrected COSMO-RS models have been proposed to improve the prediction performance based on the experimental data,but only one model is with universal parameters.The newly determined experimental results were further used to verify the perditions of original and corrected COSMO-RS models.The comparison indicates that the original COSMO-RS qualitatively predicts CO_(2)solubility for some but not all ILs/DESs,while the quantitative prediction is incapable at all.The original COSMO-RS is capable to predict CO_(2)Henry’s constant qualitatively for both physical-based ILs and DESs,and quantitative prediction is only available for DESs.For the corrected COSMO-RS models,only the model with universal parameters provides quantitative predictions for CO_(2)solubility in physical-based DESs,while other corrected models always show large deviations(>83%)compared with the experimental CO_(2)Henry’s constants.展开更多
Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic par...Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic parameters calculated by the multi-Gaussian-DAEM accurately represented the experimental conversion rate curves.Overall,the feedstock combustion could be divided into four stages:the decomposition of hemicellulose,cellulose,lignin,and char combustion.The hydrochar combustion could in turn be divided into three stages:the combustion of cellulose,lignin,and char.The mean activation energy ranges obtained for the cellulose,lignin,and char were 273.7-292.8,315.1-334.5,and 354.4-370 kJ/mol,respectively,with the standard deviations of 2.1-23.1,9.5-27.4,and 12.1-22.9 kJ/mol,re-spectively.The cellulose and lignin contents first increased and then decreased with increasing hydrothermal carbonization(HTC)temperature,while the mass fraction of char gradually increased.展开更多
The increasing CO_(2) emission,as the chief culprit causing numerous environmental problems,could be addressed by the electrochemical CO_(2) reduction(CO_(2)R)to the added-value carbon-based chemicals.Ionic liquids(IL...The increasing CO_(2) emission,as the chief culprit causing numerous environmental problems,could be addressed by the electrochemical CO_(2) reduction(CO_(2)R)to the added-value carbon-based chemicals.Ionic liquids(ILs)as electrolytes and co-catalysts have been widely studied to promote CO_(2)R owing to their unique advantages.Among the potential products of CO_(2)R,those only containing one carbon atom,named C1 products,including CO,CH_(3)OH,CH_(4),and syngas,are easier to achieve than others.In this study,we first summarized the research status on CO_(2)R to these C1 products,and then,the state-of-theart experimental results were used to evaluate the economic potential and environmental impact.Considering the rapid development in CO_(2)R,future scenarios with better CO_(2)R performances were reasonably assumed to predict the future business for each product.Among the studied C1 products,the research focuses on CO,where satisfactory results have been achieved.The evaluation shows that producing CO via CO_(2)R is the only profitable route at present.CH3OH and syngas of H2/CO(1:1)as the targeted products can become profitable in the foreseen future.In addition,the life cycle assessment(LCA)was used to evaluate the environmental impact,showing that CO_(2)R to CH4 is the most environmentally friendly pathway,followed by the syngas of H_(2)/CO(2:1)and CO,and the further improvement of the CO_(2)R performance can make all the studied C1 products more environmentally friendly.Overall,CO is the most promising product from both economic and environmental impact aspects.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51874127 and 51904099)the Graduate Training and Innovation Practice Base of Hunan Province。
文摘Zn content is one of the most concerned factors in the development of next generation ultra-strength Al-Zn-Mg-Cu alloys owing to its essential role in precipitation strengthening.In the present work,the underlying functions of Zn content in precipitation evolution and strengthening function of Al-Zn-Mg-Cu alloys were systematically investigated by combining multiple experiments and an integrated internalstate-variable model.The experimental results indicated that the increased Zn content in Al-Zn-Mg-Cu alloys would promote the development of precipitates and enhance aging hardening.The diffusion flux of soluble Zn and the coordination of Mg atom controlled the crystallographic microstructures evolution during precipitates nucleation,growth and transition processes.By integrating precipitation development with electrical resistivity and hardness evolutions,an improved internal-state-variable physical model was then developed for the aging responses of Al-Zn-Mg-Cu alloys.The unified model considered the intrinsic characteristics of precipitates such as crystallographic orientation,morphology,component,and distribution.The specific improvements were to balance the combined functions of Zn element and Mg element and consider the plate-like morphology and directed growth as indicated by experiments.This model was also adaptive to heat-treatment variables and chemical compositions,and owned the notable advantages to simultaneously rationalize the observed microstructural characteristics,mechanical and electrical properties following artificial aging of Al-Zn-Mg-Cu alloys.In addition,a preliminary model framework between electrical resistivity and hardness for Al-Zn-Mg-Cu alloys was established.
基金financially supported by the Natural Science Foundation of China (Nos.U1610101 and 21776288)the Green Process Manufacturing Innovation Research Institute, Chinese Academy of Sciences (No.IAGM-2019-A09)the funding support from Vinnova (Dn: 2018-05293)。
文摘A type of calcium coke was developed for use in the oxy-thermal process of calcium carbide production.The calcium coke was prepared by the co-pyrolysis of coking coal and calcium carbide slag, which is a solid waste generated from the chlor-alkali industry.The characteristics of the calcium cokes under different conditions were analyzed experimentally and theoretically.The results show that the thermal strength of calcium coke increased with the increase in the coking coal proportion, and the waterproof property of calcium coke also increased with increased carbonation time.The calcium coke can increase the contact area of calcium and carbon in the calcium carbide production process.Furthermore, the pore structure of the calcium coke can enhance the diffusion of gas inside the furnace, thus improving the efficiency of the oxy-thermal technology.
基金financially supported by the Joint Research Fund for Overseas Chinese Scholars and Scholars in Hong Kong and Macao Young Scholars(No.21729601)the National Natural Science Foundation of China(No.21838004)+2 种基金financial support from Carl Tryggers Stiftelse foundation(No.18:175)financial support from Swedish Energy Agency(P50830-1)financial support from National Natural Science Foundation of China(No.21878143)。
文摘The heat capacity of ionic liquids is an important physical property,and experimental measuring is usually used as a common method to obtain them.Owing to the huge number of ionic liquids that can be potentially synthesized,it is desirable to acquire theoretical predictions.In this work,the Conductor-like Screening Model for Real Solvents(COSMO-RS)was used to predict the heat capacity of pure ionic liquids,and an intensive literature survey was conducted for providing a database to verify the prediction of COSMO-RS.The survey shows that the heat capacity is available for 117 ionic liquids at temperatures ranging 77.66-520 K since 2004,and the 4025 data points in total with the values from 76.37 to 1484 J·mol^(-1)·K^(-1) have been reported.The prediction of heat capacity with COSMO-RS can only be conducted at two temperatures(298 and 323 K).The comparison with the experimental data proves the prediction reliability of COSMO-RS,and the average relative deviation(ARD)is 8.54%.Based on the predictions at two temperatures,a linear equation was obtained for each ionic liquid,and the heat capacities at other temperatures were then estimated via interpolation and extrapolation.The acquired heat capacities at other temperatures were then compared with the experimental data,and the ARD is only 9.50%.This evidences that the heat capacity of a pure ionic liquid follows a linear equation within the temperature range of study,and COSMO-RS can be used to predict the heat capacity of ionic liquids reliably.
基金financially supported by Carl Tryggers Stiftelse foundation(No.18:175)the financial support from the Swedish Energy Agency(P47500-1)+5 种基金K.C.Wang Education Foundation(No.GJTD-201804)the financial support from the National Natural Science Foundation of China(No.21890764)the financial supports from the National Natural Science Foundation of China(No.21838010)the financial support from the National Natural Science Foundation of China(No.21776276)the National Natural Science Foundation of China(21701024)the Foundation for Distinguished Young Talents in Higher Education of Fujian Province(GY-Z17067)
文摘The CO_(2)solubilities(including CO_(2)Henry’s constant)in physical-and chemical-based ILs/DESs and the COSMO-RS models describing these properties were comprehensively collected and summarized.The summarized results indicate that chemical-based ILs/DESs are superior to physical-based ILs/DESs for CO_(2)capture,especially those ILs have functionalized cation and anion,and superbase DESs;some of the superbase DESs have higher CO_(2)solubilities than those of ILs;the best physical-and chemical-based ILs,as well as physical-and chemicalbased DESs are[BMIM][BF4](4.20 mol kg^(-1)),[DETAH][Im](11.91 mol kg^(-1)),[L-Arg]-Gly 1:6(4.92 mol kg^(-1))and TBD-EG 1:4(12.90 mol kg^(-1)),respectively.Besides the original COSMO-RS mainly providing qualitative predictions,six corrected COSMO-RS models have been proposed to improve the prediction performance based on the experimental data,but only one model is with universal parameters.The newly determined experimental results were further used to verify the perditions of original and corrected COSMO-RS models.The comparison indicates that the original COSMO-RS qualitatively predicts CO_(2)solubility for some but not all ILs/DESs,while the quantitative prediction is incapable at all.The original COSMO-RS is capable to predict CO_(2)Henry’s constant qualitatively for both physical-based ILs and DESs,and quantitative prediction is only available for DESs.For the corrected COSMO-RS models,only the model with universal parameters provides quantitative predictions for CO_(2)solubility in physical-based DESs,while other corrected models always show large deviations(>83%)compared with the experimental CO_(2)Henry’s constants.
基金the National Nat-ural Science Foundation of China(Nos.52074029,51804026)the USTB-NTUT Joint Research Program(No.06310063)Chuan Wang would like to acknowledge the funding support from Vinnova(dnr:2017-01327).
文摘Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic parameters calculated by the multi-Gaussian-DAEM accurately represented the experimental conversion rate curves.Overall,the feedstock combustion could be divided into four stages:the decomposition of hemicellulose,cellulose,lignin,and char combustion.The hydrochar combustion could in turn be divided into three stages:the combustion of cellulose,lignin,and char.The mean activation energy ranges obtained for the cellulose,lignin,and char were 273.7-292.8,315.1-334.5,and 354.4-370 kJ/mol,respectively,with the standard deviations of 2.1-23.1,9.5-27.4,and 12.1-22.9 kJ/mol,re-spectively.The cellulose and lignin contents first increased and then decreased with increasing hydrothermal carbonization(HTC)temperature,while the mass fraction of char gradually increased.
基金This work was financially supported by the Swedish Energy Agency(51239-1 or P2020-90066).
文摘The increasing CO_(2) emission,as the chief culprit causing numerous environmental problems,could be addressed by the electrochemical CO_(2) reduction(CO_(2)R)to the added-value carbon-based chemicals.Ionic liquids(ILs)as electrolytes and co-catalysts have been widely studied to promote CO_(2)R owing to their unique advantages.Among the potential products of CO_(2)R,those only containing one carbon atom,named C1 products,including CO,CH_(3)OH,CH_(4),and syngas,are easier to achieve than others.In this study,we first summarized the research status on CO_(2)R to these C1 products,and then,the state-of-theart experimental results were used to evaluate the economic potential and environmental impact.Considering the rapid development in CO_(2)R,future scenarios with better CO_(2)R performances were reasonably assumed to predict the future business for each product.Among the studied C1 products,the research focuses on CO,where satisfactory results have been achieved.The evaluation shows that producing CO via CO_(2)R is the only profitable route at present.CH3OH and syngas of H2/CO(1:1)as the targeted products can become profitable in the foreseen future.In addition,the life cycle assessment(LCA)was used to evaluate the environmental impact,showing that CO_(2)R to CH4 is the most environmentally friendly pathway,followed by the syngas of H_(2)/CO(2:1)and CO,and the further improvement of the CO_(2)R performance can make all the studied C1 products more environmentally friendly.Overall,CO is the most promising product from both economic and environmental impact aspects.
