In this paper, the kind of remanent small molecules in unsaturated polyester res(?) (UP resin) , the best extractant and the best suitalbe extractive time for measuring the content of these small molecules were studie...In this paper, the kind of remanent small molecules in unsaturated polyester res(?) (UP resin) , the best extractant and the best suitalbe extractive time for measuring the content of these small molecules were studied using ultraviolet- visible spectrophotometry ( UV-VIS method). According to the principle of additivity lightness absorption for mixid solution, the contents of samll molecules in several kinds of cured UP resin were measured. It is pointed out that the UV-VIS method in the assay quality of food grade GRP products is more suitable to China.展开更多
Owing to its high theoretical capacity and low cost,Sn has attracted significant attention in sodium-ion batteries.However,the slow kinetics of electrochemical reactions and the rapid decay of capacity resulting from ...Owing to its high theoretical capacity and low cost,Sn has attracted significant attention in sodium-ion batteries.However,the slow kinetics of electrochemical reactions and the rapid decay of capacity resulting from drastic changes in the volume of Sn,as well as persistent side reactions between Sn and the organic electrolyte during the(de)sodium process,have limited its commercialization.To improve the electrochemical performance of Sn-based materials,the bottom-up method is normally used to prepare carbon-coated nanoparticles.However,its complex preparation processes and harsh conditions make it unsuitable for practical applications.Herein,a carbon-coated hybrid crystal composite(Sn/SnO_(x)@C)was prepared using an up-bottom method with commercial Sn/SnO nanoparticles.Various effects accelerate the electrochemical kinetics and inhibit the coarsening of Sn crystals.The Sn/SnO_(x)@C composite electrode exhibited capacity retention of 80.7%even after approximately 1000 cycles(360.4 mAh·g^(−1)) at a current density of 1 A·g^(−1).The high-load Na_(3)V_(2)(PO4)3||Sn/SnO_(x)@C full cell presents a capacity retention rate of 91.7%after 150 cycles at the current density of 0.5 A·g^(−1).This work may significantly accelerate the commercialization of the Sn/SnO_(x)@C composite in sodium-ion batteries with high energy density.展开更多
文摘In this paper, the kind of remanent small molecules in unsaturated polyester res(?) (UP resin) , the best extractant and the best suitalbe extractive time for measuring the content of these small molecules were studied using ultraviolet- visible spectrophotometry ( UV-VIS method). According to the principle of additivity lightness absorption for mixid solution, the contents of samll molecules in several kinds of cured UP resin were measured. It is pointed out that the UV-VIS method in the assay quality of food grade GRP products is more suitable to China.
基金This study was financially supported by the National Natural Science Foundation of China(Nos.50835002 and 51105102).
文摘Owing to its high theoretical capacity and low cost,Sn has attracted significant attention in sodium-ion batteries.However,the slow kinetics of electrochemical reactions and the rapid decay of capacity resulting from drastic changes in the volume of Sn,as well as persistent side reactions between Sn and the organic electrolyte during the(de)sodium process,have limited its commercialization.To improve the electrochemical performance of Sn-based materials,the bottom-up method is normally used to prepare carbon-coated nanoparticles.However,its complex preparation processes and harsh conditions make it unsuitable for practical applications.Herein,a carbon-coated hybrid crystal composite(Sn/SnO_(x)@C)was prepared using an up-bottom method with commercial Sn/SnO nanoparticles.Various effects accelerate the electrochemical kinetics and inhibit the coarsening of Sn crystals.The Sn/SnO_(x)@C composite electrode exhibited capacity retention of 80.7%even after approximately 1000 cycles(360.4 mAh·g^(−1)) at a current density of 1 A·g^(−1).The high-load Na_(3)V_(2)(PO4)3||Sn/SnO_(x)@C full cell presents a capacity retention rate of 91.7%after 150 cycles at the current density of 0.5 A·g^(−1).This work may significantly accelerate the commercialization of the Sn/SnO_(x)@C composite in sodium-ion batteries with high energy density.
