Density,viscosity and ultrasonic v elocity of solutions of four Schiff bases in 1,4-dioxane and dimethylfor -mamide(DMF )were measured at 308.15K.Various acoustical properties such as specific impedance(Z),adiabatic c...Density,viscosity and ultrasonic v elocity of solutions of four Schiff bases in 1,4-dioxane and dimethylfor -mamide(DMF )were measured at 308.15K.Various acoustical properties such as specific impedance(Z),adiabatic compressibility(κ s ),Rao’s molar sound function(R m ),the van der Waals constant (b),molar compressibility(W),intermolecular free length(L f ),relaxation strength(r),solvation number(S n ),were calculated.The results are in terpret-ed in terms of molecular interactions occurring in the solutions.展开更多
1,4-dioxane （DOA） was originally used to pretreat the lithium metal electrode in order to improve its interface stability. Electrochemical impedance spectra （EIS） measurements reveal that with DOA pretreatment, li...1,4-dioxane （DOA） was originally used to pretreat the lithium metal electrode in order to improve its interface stability. Electrochemical impedance spectra （EIS） measurements reveal that with DOA pretreatment, lithium electrode has a low and stable interfacial resistance during the storage in electrolyte for a long time. And it is also found that the pretreated lithium electrode has an improved interfacial performance in repeated charge/discharge cycles. Furthermore, it is proved by SEM that the pretreated one has smooth morphology after long-time storage or repeated charge/discharge cycles. Consequentially, because of more stable interface characteristics of lithium electrode, the rechargeable lithium cell with DOA pretreated lithium anode has an obviously enhanced discharging performance and a better cycleability, compared with that of the cell using the untreated lithium anode.展开更多
The copolymerization of DL-LA and 3-BMG was carried out in bulk with stannous 2-ethythexanoate as the catalyst. A series of copolymers with pendant protected groups were obtained and characterized by H-1-NMR and GPC a...The copolymerization of DL-LA and 3-BMG was carried out in bulk with stannous 2-ethythexanoate as the catalyst. A series of copolymers with pendant protected groups were obtained and characterized by H-1-NMR and GPC analysis. The monomer reactivity ratios were evaluated by the Fineman-Ross method and the Kelen-Tudos method and found to be r(BMG)=1.96 and r(LA)=0.37, respectively.展开更多
A method for the determination of 1,4-dioxane in washing food has been developed by using solid-phase microextraction technology coupled with gas chromatography-mass(SPME/GC-MS).The different SPME fibers were studied,...A method for the determination of 1,4-dioxane in washing food has been developed by using solid-phase microextraction technology coupled with gas chromatography-mass(SPME/GC-MS).The different SPME fibers were studied,in which the SPME of DVB/CAR/PDMS(50/30 μm) showed high sensitivity and selectivity for the determination of 1,4-dioxane.The calibration curve was y=3.53×105x+397 with the correlation coefficient of 0.998 8.The linear range was range of 0.05-50 mg/kg and the detection limit of 1,4-dioxane was 0.05 mg/kg with RSD of 1.01%(n=6).展开更多
文摘Density,viscosity and ultrasonic v elocity of solutions of four Schiff bases in 1,4-dioxane and dimethylfor -mamide(DMF )were measured at 308.15K.Various acoustical properties such as specific impedance(Z),adiabatic compressibility(κ s ),Rao’s molar sound function(R m ),the van der Waals constant (b),molar compressibility(W),intermolecular free length(L f ),relaxation strength(r),solvation number(S n ),were calculated.The results are in terpret-ed in terms of molecular interactions occurring in the solutions.
基金the Foundation of Science-Technology Research Program of Guangdong Province (No.2003C105006) the Foundation of Key Science-Technology Program of Guangdong Province (No.2003A1100101)
文摘1,4-dioxane （DOA） was originally used to pretreat the lithium metal electrode in order to improve its interface stability. Electrochemical impedance spectra （EIS） measurements reveal that with DOA pretreatment, lithium electrode has a low and stable interfacial resistance during the storage in electrolyte for a long time. And it is also found that the pretreated lithium electrode has an improved interfacial performance in repeated charge/discharge cycles. Furthermore, it is proved by SEM that the pretreated one has smooth morphology after long-time storage or repeated charge/discharge cycles. Consequentially, because of more stable interface characteristics of lithium electrode, the rechargeable lithium cell with DOA pretreated lithium anode has an obviously enhanced discharging performance and a better cycleability, compared with that of the cell using the untreated lithium anode.
基金This work was supported by the Major State Basic Research Program of China (Grant No. G1999064704).
文摘The copolymerization of DL-LA and 3-BMG was carried out in bulk with stannous 2-ethythexanoate as the catalyst. A series of copolymers with pendant protected groups were obtained and characterized by H-1-NMR and GPC analysis. The monomer reactivity ratios were evaluated by the Fineman-Ross method and the Kelen-Tudos method and found to be r(BMG)=1.96 and r(LA)=0.37, respectively.
文摘A method for the determination of 1,4-dioxane in washing food has been developed by using solid-phase microextraction technology coupled with gas chromatography-mass(SPME/GC-MS).The different SPME fibers were studied,in which the SPME of DVB/CAR/PDMS(50/30 μm) showed high sensitivity and selectivity for the determination of 1,4-dioxane.The calibration curve was y=3.53×105x+397 with the correlation coefficient of 0.998 8.The linear range was range of 0.05-50 mg/kg and the detection limit of 1,4-dioxane was 0.05 mg/kg with RSD of 1.01%(n=6).
