The pale green powder of nickel L-threonate Ni（C4H7O5）2·2H2O was prepared from excess nickelous dihydroxycarbonate and L-threonic acid obtained by double decomposition reaction of calcium L-threonate with oxali...The pale green powder of nickel L-threonate Ni（C4H7O5）2·2H2O was prepared from excess nickelous dihydroxycarbonate and L-threonic acid obtained by double decomposition reaction of calcium L-threonate with oxalic acid at 80 ℃ for 2 h. The IR spectra indicated that Ni 2+ was in coordination with oxygen atom of the carboxyl group of L-threonic acid with coordination number of 4. The TG-DTG results showed the compound discomposes into NiO at 380 ℃ in nitrogen atmosphere. The constant volume combustion energy of the compound, ΔcE, determined by a precise rotating-bomb combustion calorimeter at 298.15 K, was （-3 515.22±1.97） kJ/mol. The standard enthalpy of combustion, ΔcH0m, and standard enthalpy of formation, ΔfH0m, were calculated to be -3 512.74±1.97 kJ/mol and -2 447.51±2.26 kJ/mol, respectively.展开更多
The PTCR(positive temperature coefficient of resistance) nanosized ceramic pow der was prepared by Sol-Gel process and characterized by XRD, DSC, SEM and BET techniques. The results showed that the nanopowder has an a...The PTCR(positive temperature coefficient of resistance) nanosized ceramic pow der was prepared by Sol-Gel process and characterized by XRD, DSC, SEM and BET techniques. The results showed that the nanopowder has an average crystallite si ze of 35nm with sphere-shaped, whose specific surface area is 27.80m2·g-1 and the crystal structure is abnormal cubical perovskite phase at room temperature. In addition, the nanopowder was pressed into pellets and then sintered accordin g to improved technique which was built based on the data of thermal analysis of the PTCR green-compact to yield PTCR ceramic materials with peculiar microstru cture and higher properties, which has a resistivity at room temperature of ～20 Ω·cm, a temperature coefficient of resistivity of ～19%·℃-1, a withstand v oltage intensity of >160V·mm-1 and a resistivity jump of >105.展开更多
Co nanowire arrays were prepared by anodic alumina oxide template,which formed during DC superposed pulse source anodization process. The structure of porous alumina template and properties of optical polarization of ...Co nanowire arrays were prepared by anodic alumina oxide template,which formed during DC superposed pulse source anodization process. The structure of porous alumina template and properties of optical polarization of Co nanowire arrays are studied with the help of the scanning electron microscope, X ray diffraction and infrared spectroscopy. The results showed that Co nanowire arrays have an excellent polarization property in near infrared region in 2700nm. We also found that the properties of optical polarization can also be controlled by adulterating kinds of electrodepositing metal and its alloys, by controlling length of nanowire, and by changing incidence angle.展开更多
The thermokinetics of liquid-liqui d reaction of samarium nitrate /dysp rosium nitrate /erbium nitrate with histidine are studied using a microcalorimeter.On the basis of experime ntal and calculated results,three t h...The thermokinetics of liquid-liqui d reaction of samarium nitrate /dysp rosium nitrate /erbium nitrate with histidine are studied using a microcalorimeter.On the basis of experime ntal and calculated results,three t hermo-dynamic parameters(the activation enthalpy,the active entropy and the activation free energy),the rate constant,three kinetic parameters(the activation energy,the pre-exponential constant and the reaction order)are obtained.The influence of temperature on the t itled reaction and the synthetic con dition of the complex have been discu ssed.展开更多
Studies of the non-isothermal decomposition of barium2,4,6-trinitroresorecinate monohydrate,Ba(TNR)·H 2 O,were carried out by means of TG-DTA,DSC and IR.The thermal decomposition mechanism and associated ki-netic...Studies of the non-isothermal decomposition of barium2,4,6-trinitroresorecinate monohydrate,Ba(TNR)·H 2 O,were carried out by means of TG-DTA,DSC and IR.The thermal decomposition mechanism and associated ki-netics were investigated.The kinetic parameters were obtained from an analysis of the DSC curves by integral and differential methods.The most probable kinetic model function of the dehydration reaction of Ba(TNR)·H 2 O was suggested by comparison of the kinetic parameters.展开更多
The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calciu...The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calcium L-threonate with oxalic acid and superfluous manganese oxide at 80℃for c ertain time.The composition of the n ew compound was determined by chemical and elemental analyses and its formu la fits Mn (C 4 H 7 O 5 ) 2 ·H 2 O,the IR spectra indicated that Mn 2+ in the compound coordinates to oxygen atom of the carboxyl group,while th e proton of the carboxyl group is dissociated,i t was assumed that the coordination n umber of Mn 2+ was 4.The results of TG-DTG showed that the compound have fairish stability,the intermediate and final product of the thermal de-composition of the compound are Mn (C 4 H 7 O 5 ) 2 and MnO 2 ,respectively.The constant volume combustion energy of the compound,Δ c E,were determined by a precise rotating-bomb calorimeter at 298.15K,it was(-3384.30±1.21)kJ·mol -1 ,its standard enthalpy of Combustio n,Δ c H m ,and standard enthalpy of formation,Δ f H m ,were calculated.They are(-3383.07±1.21)kJ·mol -1 and(-2571.68±1.63)kJ·mol -1 ,respectively.展开更多
Using KMnO4 and MnCl2·4H2O as raw materials,nanometersized KMn8O16 was prepared by solid state reaction at room temperature.XRD,SEM,FT-IR and surface area measurement techniques were used to investigate the compo...Using KMnO4 and MnCl2·4H2O as raw materials,nanometersized KMn8O16 was prepared by solid state reaction at room temperature.XRD,SEM,FT-IR and surface area measurement techniques were used to investigate the composition,size,morphology and properties of KMn8O16 powder.The results show that the powder has an average diameter of 20 nm with sphere-like and good dispersity and higher for H2O2 decomposition.展开更多
文摘The pale green powder of nickel L-threonate Ni（C4H7O5）2·2H2O was prepared from excess nickelous dihydroxycarbonate and L-threonic acid obtained by double decomposition reaction of calcium L-threonate with oxalic acid at 80 ℃ for 2 h. The IR spectra indicated that Ni 2+ was in coordination with oxygen atom of the carboxyl group of L-threonic acid with coordination number of 4. The TG-DTG results showed the compound discomposes into NiO at 380 ℃ in nitrogen atmosphere. The constant volume combustion energy of the compound, ΔcE, determined by a precise rotating-bomb combustion calorimeter at 298.15 K, was （-3 515.22±1.97） kJ/mol. The standard enthalpy of combustion, ΔcH0m, and standard enthalpy of formation, ΔfH0m, were calculated to be -3 512.74±1.97 kJ/mol and -2 447.51±2.26 kJ/mol, respectively.
文摘The PTCR(positive temperature coefficient of resistance) nanosized ceramic pow der was prepared by Sol-Gel process and characterized by XRD, DSC, SEM and BET techniques. The results showed that the nanopowder has an average crystallite si ze of 35nm with sphere-shaped, whose specific surface area is 27.80m2·g-1 and the crystal structure is abnormal cubical perovskite phase at room temperature. In addition, the nanopowder was pressed into pellets and then sintered accordin g to improved technique which was built based on the data of thermal analysis of the PTCR green-compact to yield PTCR ceramic materials with peculiar microstru cture and higher properties, which has a resistivity at room temperature of ～20 Ω·cm, a temperature coefficient of resistivity of ～19%·℃-1, a withstand v oltage intensity of >160V·mm-1 and a resistivity jump of >105.
文摘Co nanowire arrays were prepared by anodic alumina oxide template,which formed during DC superposed pulse source anodization process. The structure of porous alumina template and properties of optical polarization of Co nanowire arrays are studied with the help of the scanning electron microscope, X ray diffraction and infrared spectroscopy. The results showed that Co nanowire arrays have an excellent polarization property in near infrared region in 2700nm. We also found that the properties of optical polarization can also be controlled by adulterating kinds of electrodepositing metal and its alloys, by controlling length of nanowire, and by changing incidence angle.
文摘The thermokinetics of liquid-liqui d reaction of samarium nitrate /dysp rosium nitrate /erbium nitrate with histidine are studied using a microcalorimeter.On the basis of experime ntal and calculated results,three t hermo-dynamic parameters(the activation enthalpy,the active entropy and the activation free energy),the rate constant,three kinetic parameters(the activation energy,the pre-exponential constant and the reaction order)are obtained.The influence of temperature on the t itled reaction and the synthetic con dition of the complex have been discu ssed.
文摘Studies of the non-isothermal decomposition of barium2,4,6-trinitroresorecinate monohydrate,Ba(TNR)·H 2 O,were carried out by means of TG-DTA,DSC and IR.The thermal decomposition mechanism and associated ki-netics were investigated.The kinetic parameters were obtained from an analysis of the DSC curves by integral and differential methods.The most probable kinetic model function of the dehydration reaction of Ba(TNR)·H 2 O was suggested by comparison of the kinetic parameters.
文摘The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calcium L-threonate with oxalic acid and superfluous manganese oxide at 80℃for c ertain time.The composition of the n ew compound was determined by chemical and elemental analyses and its formu la fits Mn (C 4 H 7 O 5 ) 2 ·H 2 O,the IR spectra indicated that Mn 2+ in the compound coordinates to oxygen atom of the carboxyl group,while th e proton of the carboxyl group is dissociated,i t was assumed that the coordination n umber of Mn 2+ was 4.The results of TG-DTG showed that the compound have fairish stability,the intermediate and final product of the thermal de-composition of the compound are Mn (C 4 H 7 O 5 ) 2 and MnO 2 ,respectively.The constant volume combustion energy of the compound,Δ c E,were determined by a precise rotating-bomb calorimeter at 298.15K,it was(-3384.30±1.21)kJ·mol -1 ,its standard enthalpy of Combustio n,Δ c H m ,and standard enthalpy of formation,Δ f H m ,were calculated.They are(-3383.07±1.21)kJ·mol -1 and(-2571.68±1.63)kJ·mol -1 ,respectively.
文摘Using KMnO4 and MnCl2·4H2O as raw materials,nanometersized KMn8O16 was prepared by solid state reaction at room temperature.XRD,SEM,FT-IR and surface area measurement techniques were used to investigate the composition,size,morphology and properties of KMn8O16 powder.The results show that the powder has an average diameter of 20 nm with sphere-like and good dispersity and higher for H2O2 decomposition.
基金by the Science and Technology Foundation of Shaanxi Key Laboratory of Physico-inorganic Chemistry(No.29-3,2001)the Science and Technology Foundation of the National Defense Key Laboratory of Propellant and Explosive Combustion of China(No.514550101,2003)
