Thermodynamic analysis of the main reactions in the process of thermal decomposition ofAl(OH)3 was made using Temkin-Schwarzman's method and by means of regression analysis.
A new method for preparing fine -Al_2O_3 by thermal decomposition from hydrazine-containing aluminum salt was described.The process of the thermal decomposition of the hydrazine-containing aluminum salt was investigat...A new method for preparing fine -Al_2O_3 by thermal decomposition from hydrazine-containing aluminum salt was described.The process of the thermal decomposition of the hydrazine-containing aluminum salt was investigated by thermal analysis(TG and DTA)and the thermally decomposed products were studied by S.E.M and X-ray diffraction.The result indicated the particles of -Al_2O_3 obtained in this way at 12500℃ were<1um in size.展开更多
The Y_2O_3 thin film was applied on Fe-3Al intermetallic compound by electrodeposition and thermal decomposition. The cyclic oxidation of the Fe-3Al specimens with and without surfaceapplied Y_2O_3 thin film was carri...The Y_2O_3 thin film was applied on Fe-3Al intermetallic compound by electrodeposition and thermal decomposition. The cyclic oxidation of the Fe-3Al specimens with and without surfaceapplied Y_2O_3 thin film was carried out at 900 ℃ in air. The results show that the selective oxidation of Al in Fe-3Al was promoted, and both of the plasticity and the adhesion of the oxide scale formed on Fe3Al were improved and the high temperature oxidation resistance of Fe3Al was enhanced markedly.展开更多
Nano-fibrous Al-stabilized α-Ni(OH)2 was synthesized by the urea thermal decomposition method. The grain morphology, crystal structure, thermal stability, chemical composition and electrochemical performance of the A...Nano-fibrous Al-stabilized α-Ni(OH)2 was synthesized by the urea thermal decomposition method. The grain morphology, crystal structure, thermal stability, chemical composition and electrochemical performance of the Al-stabilized α-Ni(OH)2 were investigated. It is found that the urea thermal decomposition is an appropriate way to precipitate the Al-stabilized α-Ni(OH)2 with excellent performance. The fiber cluster TEM pattern shows that the synthesized α-Ni(OH)2 powder is composed of agglomerates of much smaller primary particles. The stabilized α-Ni(OH)2 powder with a 7.67 c-axis distance and low thermal stabilities is obtained. The FTIR spectrum shows that the materials contain absorbed water molecules, and intercalated CO32- and SO42- anions. The experimental α-Ni(OH)2 electrode exhibits excellent electrochemical redox reversibility, high special capacity, good rate discharging performance and perfect cyclic stability. Moreover, the synthesized α-Ni(OH)2 electrode also shows high discharge capacity and cyclic stability at high temperature. The electrode specific capacity remains 290 mA·h/g at 60 ℃, which is only 15 mA·h/g lower than its ambient value, and the capacity loss is 0.9 mA·h/g per charge-discharge cycle.展开更多
The heat capacities of 3-（ 2,2-dichloroethenyl）-2,2-dimethylcyclopropanecarboxylic acid （a racemic mixture, molar ratio of cis-/trans-structure is 35/65） in a temperature range from 78 to 389 K were measured with ...The heat capacities of 3-（ 2,2-dichloroethenyl）-2,2-dimethylcyclopropanecarboxylic acid （a racemic mixture, molar ratio of cis-/trans-structure is 35/65） in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% （ molar fraction）. A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and en- tropy of fusion, △fusHm, △fusSm, of the acid were determined to be （331.48±0.03 ） K, （16.321±0.031） kJ/mol, and （49.24±0.19） J/（ K·mol）, respectively. The thermodynamic functions of the sample, Ht-H298.15, Sr-S298.15 and Gr-G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric（TG） analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7.3 ×10^7 min^-1 , E =70.64 kJ/mol, respectively.展开更多
A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was stu...A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was studied and discussed by phenomenological model. It is suggested that ultrafine monodispersed colloidal particles of Y(OH)CO3 are stable only in a very narrow temporary supersaturation range ( 1<x<1 .08).展开更多
文摘Thermodynamic analysis of the main reactions in the process of thermal decomposition ofAl(OH)3 was made using Temkin-Schwarzman's method and by means of regression analysis.
文摘A new method for preparing fine -Al_2O_3 by thermal decomposition from hydrazine-containing aluminum salt was described.The process of the thermal decomposition of the hydrazine-containing aluminum salt was investigated by thermal analysis(TG and DTA)and the thermally decomposed products were studied by S.E.M and X-ray diffraction.The result indicated the particles of -Al_2O_3 obtained in this way at 12500℃ were<1um in size.
文摘The Y_2O_3 thin film was applied on Fe-3Al intermetallic compound by electrodeposition and thermal decomposition. The cyclic oxidation of the Fe-3Al specimens with and without surfaceapplied Y_2O_3 thin film was carried out at 900 ℃ in air. The results show that the selective oxidation of Al in Fe-3Al was promoted, and both of the plasticity and the adhesion of the oxide scale formed on Fe3Al were improved and the high temperature oxidation resistance of Fe3Al was enhanced markedly.
文摘Nano-fibrous Al-stabilized α-Ni(OH)2 was synthesized by the urea thermal decomposition method. The grain morphology, crystal structure, thermal stability, chemical composition and electrochemical performance of the Al-stabilized α-Ni(OH)2 were investigated. It is found that the urea thermal decomposition is an appropriate way to precipitate the Al-stabilized α-Ni(OH)2 with excellent performance. The fiber cluster TEM pattern shows that the synthesized α-Ni(OH)2 powder is composed of agglomerates of much smaller primary particles. The stabilized α-Ni(OH)2 powder with a 7.67 c-axis distance and low thermal stabilities is obtained. The FTIR spectrum shows that the materials contain absorbed water molecules, and intercalated CO32- and SO42- anions. The experimental α-Ni(OH)2 electrode exhibits excellent electrochemical redox reversibility, high special capacity, good rate discharging performance and perfect cyclic stability. Moreover, the synthesized α-Ni(OH)2 electrode also shows high discharge capacity and cyclic stability at high temperature. The electrode specific capacity remains 290 mA·h/g at 60 ℃, which is only 15 mA·h/g lower than its ambient value, and the capacity loss is 0.9 mA·h/g per charge-discharge cycle.
基金Supported by the Education Bureau Science Foundation of Liaoning Province,China(No.20040261).
文摘The heat capacities of 3-（ 2,2-dichloroethenyl）-2,2-dimethylcyclopropanecarboxylic acid （a racemic mixture, molar ratio of cis-/trans-structure is 35/65） in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% （ molar fraction）. A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and en- tropy of fusion, △fusHm, △fusSm, of the acid were determined to be （331.48±0.03 ） K, （16.321±0.031） kJ/mol, and （49.24±0.19） J/（ K·mol）, respectively. The thermodynamic functions of the sample, Ht-H298.15, Sr-S298.15 and Gr-G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric（TG） analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7.3 ×10^7 min^-1 , E =70.64 kJ/mol, respectively.
文摘A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was studied and discussed by phenomenological model. It is suggested that ultrafine monodispersed colloidal particles of Y(OH)CO3 are stable only in a very narrow temporary supersaturation range ( 1<x<1 .08).
