Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely comme...Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB.展开更多
An Ayurvedic medicine, Liv-52 has been studied as a prophylactic against beryllium induced toxicity in rats. Administration of beryllium per se caused severe degenerative and necrotic changes in liver, kidney, lungs a...An Ayurvedic medicine, Liv-52 has been studied as a prophylactic against beryllium induced toxicity in rats. Administration of beryllium per se caused severe degenerative and necrotic changes in liver, kidney, lungs and spleen. Its administration reduced glycogen content, activity of alkaline phosphatase and adenosine triphosphatase in these oreans. On the contrary, activities of acid phosphatase and glucose-6-phosphatase were increased singificantly. In Liv-52 primed rats significant recoupment was observed in all the parameters展开更多
Modeling the application of train operation adjustment actions to recover from delays is of great importance to supporting the decision-making of dispatchers.In this study,the effects of two train operation adjustment...Modeling the application of train operation adjustment actions to recover from delays is of great importance to supporting the decision-making of dispatchers.In this study,the effects of two train operation adjustment actions on train delay recovery were explored using train operation records from scheduled and actual train timetables.First,the modeling data were sorted to extract the possible influencing factors under two typical train operation adjustment actions,namely the compression of the train dwell time at stations and the compression of the train running time in sections.Stepwise regression methods were then employed to determine the importance of the influencing factors corresponding to the train delay recovery time,namely the delay time,the scheduled supplement time,the running interval,the occurrence time,and the place where the delay occurred,under the two train operation adjustment actions.Finally,the gradient-boosted regression tree(GBRT)algorithm was applied to construct a delay recovery model to predict the delay recovery effects of the train operation adjustment actions.A comparison of the prediction results of the GBRT model with those of a random forest model confirmed the better performance of the GBRT prediction model.展开更多
Chitosan,a renewable,non-toxic,and natural cationic polyelectrolyte,can be combined with many anionic polyelectrolytes(such as sodium alginate,hyaluronic acid,xylan,and gelatin)via electrostatic forces to form chitosa...Chitosan,a renewable,non-toxic,and natural cationic polyelectrolyte,can be combined with many anionic polyelectrolytes(such as sodium alginate,hyaluronic acid,xylan,and gelatin)via electrostatic forces to form chitosan-based polyelectrolyte composites under certain conditions.This review summarizes various methods of preparing chitosan-based polyelectrolyte composites and analyzes their applications in clinical medicine and agriculture,as well as pharmaceutical,tissue,food,environmental,and textile engineering fields.The future development direction and potential of chitosan-based polyelectrolytes are also discussed.展开更多
基金This work was supported by the National Natural Science Foundation of China(52203066,51973157,61904123)the Tianjin Natural Science Foundation(18JCQNJC02900)+3 种基金the National innovation and entrepreneurship training program for college students(202310058007)the Tianjin Municipal college students’innovation and entrepreneurship training program(202310058088)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(Grant No.2018KJ196)the State Key Laboratory of Membrane and Membrane Separation,Tiangong University.
文摘Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB.
文摘An Ayurvedic medicine, Liv-52 has been studied as a prophylactic against beryllium induced toxicity in rats. Administration of beryllium per se caused severe degenerative and necrotic changes in liver, kidney, lungs and spleen. Its administration reduced glycogen content, activity of alkaline phosphatase and adenosine triphosphatase in these oreans. On the contrary, activities of acid phosphatase and glucose-6-phosphatase were increased singificantly. In Liv-52 primed rats significant recoupment was observed in all the parameters
基金the National Nature Science Foundation of China(Nos.71871188 and U1834209)the Science and Technology Department of Sichuan Province(No.2018JY0567)。
文摘Modeling the application of train operation adjustment actions to recover from delays is of great importance to supporting the decision-making of dispatchers.In this study,the effects of two train operation adjustment actions on train delay recovery were explored using train operation records from scheduled and actual train timetables.First,the modeling data were sorted to extract the possible influencing factors under two typical train operation adjustment actions,namely the compression of the train dwell time at stations and the compression of the train running time in sections.Stepwise regression methods were then employed to determine the importance of the influencing factors corresponding to the train delay recovery time,namely the delay time,the scheduled supplement time,the running interval,the occurrence time,and the place where the delay occurred,under the two train operation adjustment actions.Finally,the gradient-boosted regression tree(GBRT)algorithm was applied to construct a delay recovery model to predict the delay recovery effects of the train operation adjustment actions.A comparison of the prediction results of the GBRT model with those of a random forest model confirmed the better performance of the GBRT prediction model.
文摘Chitosan,a renewable,non-toxic,and natural cationic polyelectrolyte,can be combined with many anionic polyelectrolytes(such as sodium alginate,hyaluronic acid,xylan,and gelatin)via electrostatic forces to form chitosan-based polyelectrolyte composites under certain conditions.This review summarizes various methods of preparing chitosan-based polyelectrolyte composites and analyzes their applications in clinical medicine and agriculture,as well as pharmaceutical,tissue,food,environmental,and textile engineering fields.The future development direction and potential of chitosan-based polyelectrolytes are also discussed.
