High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluor...High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluoride for roasting.Under the optimal leaching conditions of a fluorine to aluminum molar ratio of 2.0,a liquid-to-solid ratio of 12,a temperature of 90℃,and time of 4 h,the fluorine leaching rate can reach 99.15%.Under the action of electrolysis,the H+is reduced to H2 in the cathode,while the remaining OH−combines with AlF^(2+)and AlF^(2+)to precipitate aluminium hydroxyfluoride hydrate.The results show that electrolysis is beneficial to reduce the impurity content of aluminium hydroxyfluoride hydrate.When the current density is 0.2 A/cm^(2),the temperature is 90℃,the stirring speed is 200 r/min,and the electrolysis endpoint pH is 3.0,the total content of Na,K and Ca impurities in the precipitation is only 0.64 wt.%.Moreover,the hydrolysis can be inhibited effectively by adding ammonium hydrogen fluoride in the mixed-roasting process.When the mass ratio of aluminium hydroxyfluoride hydrate to ammonium hydrogen fluoride is 2꞉1,the purity of the AlF3 product is even 99.51 wt.%.Conducively,the high-purity AlF_(3)can be returned to the aluminum electrolysis industry or used as a reagent.展开更多
The contraction of isolated rat and rabbit uteri induced by oxytocin and PGF2α was markedly inhibited by chlorpheniramine (Chl) and astemizolum (Ast) , both of which also decreased the resting tension of uteri, and t...The contraction of isolated rat and rabbit uteri induced by oxytocin and PGF2α was markedly inhibited by chlorpheniramine (Chl) and astemizolum (Ast) , both of which also decreased the resting tension of uteri, and their spontaneous contraction. The inhibitory effects of both drugs were dose-dependent. At high concentrations , Chl 7. 4 × 10-4 mol/L and Ast 10-4 mol/L could counteract the contraction of the uteri induced by Oxy and PGF2α, and their spontaneous contraction as well. They decreased the resting tension to the lower level. The mechanism of their non-special relaxed action on uteri could not be completely explained only by their H1-receptor blocking action. Whether they act by blocking calcium channel or by inhibiting calmodulin (CaM) remains to be further explored.展开更多
The catalyst layer is an essential component of fuel cells,exerting a decisive influence on performance,particularly under degradation processes.Characterization derived from accelerated stress tests(ASTs)provide valu...The catalyst layer is an essential component of fuel cells,exerting a decisive influence on performance,particularly under degradation processes.Characterization derived from accelerated stress tests(ASTs)provide valuable insights into the long-term degradation from the perspective of changes in physical and chemical properties,thereby offering a scientific foundation for evaluating advanced materials and strategies.In this review,multidimensional and multi-characterization application scenarios based on ASTs data are systematically summarized.Firstly,the degradation mechanism of catalyst layer(CL)under AST conditions is discussed,with an emphasis on platinum aging and carbon support corrosion.In addition,electrochemical and microphysical characterization tools applicable to different AST test protocols,such as electrochemical surface area(ECSA),electrochemical impedance spectrum(EIS)mapping combined with distribution of relaxation times(DRT),and microscopic physical evolution and tracking techniques for each internal chemical component,are also presented in detail.Finally,through the existing research progress and hotspots,the application prospect of data fusion is elaborated and the important research direction of material optimization and performance prediction based on AST data is emphasized,aiming to provide insights into the study of catalytic layer degradation in fuel cells and promote the continuous development of the field.展开更多
文摘High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluoride for roasting.Under the optimal leaching conditions of a fluorine to aluminum molar ratio of 2.0,a liquid-to-solid ratio of 12,a temperature of 90℃,and time of 4 h,the fluorine leaching rate can reach 99.15%.Under the action of electrolysis,the H+is reduced to H2 in the cathode,while the remaining OH−combines with AlF^(2+)and AlF^(2+)to precipitate aluminium hydroxyfluoride hydrate.The results show that electrolysis is beneficial to reduce the impurity content of aluminium hydroxyfluoride hydrate.When the current density is 0.2 A/cm^(2),the temperature is 90℃,the stirring speed is 200 r/min,and the electrolysis endpoint pH is 3.0,the total content of Na,K and Ca impurities in the precipitation is only 0.64 wt.%.Moreover,the hydrolysis can be inhibited effectively by adding ammonium hydrogen fluoride in the mixed-roasting process.When the mass ratio of aluminium hydroxyfluoride hydrate to ammonium hydrogen fluoride is 2꞉1,the purity of the AlF3 product is even 99.51 wt.%.Conducively,the high-purity AlF_(3)can be returned to the aluminum electrolysis industry or used as a reagent.
文摘The contraction of isolated rat and rabbit uteri induced by oxytocin and PGF2α was markedly inhibited by chlorpheniramine (Chl) and astemizolum (Ast) , both of which also decreased the resting tension of uteri, and their spontaneous contraction. The inhibitory effects of both drugs were dose-dependent. At high concentrations , Chl 7. 4 × 10-4 mol/L and Ast 10-4 mol/L could counteract the contraction of the uteri induced by Oxy and PGF2α, and their spontaneous contraction as well. They decreased the resting tension to the lower level. The mechanism of their non-special relaxed action on uteri could not be completely explained only by their H1-receptor blocking action. Whether they act by blocking calcium channel or by inhibiting calmodulin (CaM) remains to be further explored.
基金supported by National Natural Science Foundation of China(22279091)Fundamental Funds for the Central Universities。
文摘The catalyst layer is an essential component of fuel cells,exerting a decisive influence on performance,particularly under degradation processes.Characterization derived from accelerated stress tests(ASTs)provide valuable insights into the long-term degradation from the perspective of changes in physical and chemical properties,thereby offering a scientific foundation for evaluating advanced materials and strategies.In this review,multidimensional and multi-characterization application scenarios based on ASTs data are systematically summarized.Firstly,the degradation mechanism of catalyst layer(CL)under AST conditions is discussed,with an emphasis on platinum aging and carbon support corrosion.In addition,electrochemical and microphysical characterization tools applicable to different AST test protocols,such as electrochemical surface area(ECSA),electrochemical impedance spectrum(EIS)mapping combined with distribution of relaxation times(DRT),and microscopic physical evolution and tracking techniques for each internal chemical component,are also presented in detail.Finally,through the existing research progress and hotspots,the application prospect of data fusion is elaborated and the important research direction of material optimization and performance prediction based on AST data is emphasized,aiming to provide insights into the study of catalytic layer degradation in fuel cells and promote the continuous development of the field.
