Poly（vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） based composite polymer electrolyte （CPE） modified with CeO2, La2O3 and Y2O3 nano-rare earth oxides was prepared by phase inversion technique. Physical...Poly（vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） based composite polymer electrolyte （CPE） modified with CeO2, La2O3 and Y2O3 nano-rare earth oxides was prepared by phase inversion technique. Physical and chemical properties of the modified CPEs were studied by SEM, TG-DSC and electrochemical methods. The results show that the CPE modified with 10% La2O3 （mass fraction） has the best practical applicability, which indicates that the thermal and electrochemical stability can reach over 400 ℃ and 4.5 V, respectively, and temperature dependence of ionic conductivity follows Vogel-Tamman-Fulcher （VTF） relationship and ionic conductivity at room temperature is up to 3.3 mS/cm. The interfacial resistance Ri reaches a stable value about 557 Ω after 6 d storage.展开更多
Poly(ethylene- co -chlorotrifluoroethylene) with a 1∶1 molar ratio of ethylene and chlorotrifluoroethylene in composition, PECTFE, is a statistically alternating copolymer widely used in cable coating industry. PECTF...Poly(ethylene- co -chlorotrifluoroethylene) with a 1∶1 molar ratio of ethylene and chlorotrifluoroethylene in composition, PECTFE, is a statistically alternating copolymer widely used in cable coating industry. PECTFE has been commonly characterized as a semicrystalline polymer with crystals melting at 238 ℃. Differential scanning calorimetry, thermal mechanical analysis and dynamic mechanical analysis indicated that PECTFE undergoes a reversible solid-solid transition during cooling and heating in the temperature range between 100 ℃ and 200 ℃. Based on detailed structural analysis via wide angle X-ray diffraction and electron diffraction techniques, we proposed that PECTFE possesses a hexagonal phase above 200 ℃( a =0 60 nm, c =0 49 nm) and an orthorhombic phase( a =0 99 nm, b =0 57 nm, c =0 49 nm) at room temperature.展开更多
Methoxy poly(ethylene glycol)-poly(D,L-lactide) block copolymers (PEG-PLA) were prepared through ring-opening polymerization.The oil in water suspension method was used to prepare block copolymer micelles. The critica...Methoxy poly(ethylene glycol)-poly(D,L-lactide) block copolymers (PEG-PLA) were prepared through ring-opening polymerization.The oil in water suspension method was used to prepare block copolymer micelles. The critical micelle concentration (CMC) by fluorescence spectroscopy was 0.0056 mg·ml -1 . The physical state of the inner core region of micelles was characterized with 1HNMR. The size of indomethacin (IMC) loaded micelles measured by dynamic light scattering (DLS) showed narrow monodisperse size distribution and the average diameters were less than 50 nm. In addition, the nanoparticles with relatively high drug loading content (DLC) were obtained.展开更多
In depth study of NO reveals that NO is a bioactive molecule that exerts a number of roles in many physiological and pathological process.NO is produced in response to drought,salinity,temperature shock and pathogen a...In depth study of NO reveals that NO is a bioactive molecule that exerts a number of roles in many physiological and pathological process.NO is produced in response to drought,salinity,temperature shock and pathogen attack.NO rapidly reacts with ROS,ABA and other hormones and directly or indirectly regulate ethylene biosynthesis.The authors review the response of between plant NO and kinds of stresses,and possible mechanism was discussed.展开更多
基金Project(2011FJ1005)supported by the Major Provincial Science and Technology Program of Hunan Province,ChinaProject(2010qzzd0101)supported by the Central College on the 2010 Operational Costs of Basic Research Program,China
文摘Poly（vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） based composite polymer electrolyte （CPE） modified with CeO2, La2O3 and Y2O3 nano-rare earth oxides was prepared by phase inversion technique. Physical and chemical properties of the modified CPEs were studied by SEM, TG-DSC and electrochemical methods. The results show that the CPE modified with 10% La2O3 （mass fraction） has the best practical applicability, which indicates that the thermal and electrochemical stability can reach over 400 ℃ and 4.5 V, respectively, and temperature dependence of ionic conductivity follows Vogel-Tamman-Fulcher （VTF） relationship and ionic conductivity at room temperature is up to 3.3 mS/cm. The interfacial resistance Ri reaches a stable value about 557 Ω after 6 d storage.
文摘Poly(ethylene- co -chlorotrifluoroethylene) with a 1∶1 molar ratio of ethylene and chlorotrifluoroethylene in composition, PECTFE, is a statistically alternating copolymer widely used in cable coating industry. PECTFE has been commonly characterized as a semicrystalline polymer with crystals melting at 238 ℃. Differential scanning calorimetry, thermal mechanical analysis and dynamic mechanical analysis indicated that PECTFE undergoes a reversible solid-solid transition during cooling and heating in the temperature range between 100 ℃ and 200 ℃. Based on detailed structural analysis via wide angle X-ray diffraction and electron diffraction techniques, we proposed that PECTFE possesses a hexagonal phase above 200 ℃( a =0 60 nm, c =0 49 nm) and an orthorhombic phase( a =0 99 nm, b =0 57 nm, c =0 49 nm) at room temperature.
文摘Methoxy poly(ethylene glycol)-poly(D,L-lactide) block copolymers (PEG-PLA) were prepared through ring-opening polymerization.The oil in water suspension method was used to prepare block copolymer micelles. The critical micelle concentration (CMC) by fluorescence spectroscopy was 0.0056 mg·ml -1 . The physical state of the inner core region of micelles was characterized with 1HNMR. The size of indomethacin (IMC) loaded micelles measured by dynamic light scattering (DLS) showed narrow monodisperse size distribution and the average diameters were less than 50 nm. In addition, the nanoparticles with relatively high drug loading content (DLC) were obtained.
文摘In depth study of NO reveals that NO is a bioactive molecule that exerts a number of roles in many physiological and pathological process.NO is produced in response to drought,salinity,temperature shock and pathogen attack.NO rapidly reacts with ROS,ABA and other hormones and directly or indirectly regulate ethylene biosynthesis.The authors review the response of between plant NO and kinds of stresses,and possible mechanism was discussed.
