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The thermodynamic property of Rare Earth Complexes with L-Threonine

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Journal of Rare Earths 1991年第4期9卷 263-267页

作者：张亚飞牛春吉倪嘉缵 Changchun Institute of Applied Chemistry Academia SinicaChangchun 130022China

In this paper the stability constants and thermodynamic parameters for complexes of rare earth elements with L-threonine have been measured systematically by potentiometry and calorimetry at 25℃ and ionic strength of 0.15 mol/L(NaCl).The thermodynamic values for protonation of the anion of L-threonine have been *** dependence of stability,enthalpy and entropy change of the complex upon atomic number of cation is investigated,and the coordination of L-threonine to rare earth is also discussed in detail.

关键词： Rare earth complex Threonine thermodynamic property

Investigation on thermodynamic property and Decomposition Kinetics of Micro and Nano RDX Explosives

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Investigation on Thermodynamic Property and Decomposition Ki...

Hydrogen storage thermodynamics and kinetics of as-cast Ce-Mg-Ni-based alloy

中国化学会第七届全国热分析动力学与热动力学学术会议

作者： Xiao-ning REN Feng-qi ZHAO Li-bai XIAO Hong-xu GAO Science and Technology on Combustion and Explosion Laboratory Xi’an Modern Chemistry Research Institute

＜正＞In recent years,the excellent properties of nanometer explosives cause world-wide attention due to the high demands of insensitive ammunition [1].With modern advanced war having higher requirements of material p... 详细信息

关键词： micro and nano explosive calorimeter μSC specific heat capacity thermodynamic property thermal analysis decomposition kinetics

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Journal of Iron and Steel Research International 2024年第3期31卷 752-766页

作者： Yan Qi Xin Zhang Jun Li Dong-liang Zhao Shi-hai Guo Yang-huan Zhang Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China China Rare Earth New Material(Weishan)Co..Ltd. Jining 277600ShandongChina Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources Inner Mongolia University of Science and TechnologyBaotou 014010Inner MongoliaChina

The reaction kinetics of alloys based on magnesium are known to be greatly improved by the partial substitution of Mg with rare earths and transition metals,particularly *** enhanced superficial hydrogen dissociation rate,the weakened Mg-H bond and the lower activation energy following element replacement are thought to be related to the better *** experimental alloys Ce5Mg_(95-x)Ni_(x)(x=5,10,15)were smelted by the vacuum induction *** phase transformation and structural evolution of experimental alloys before and after reaction with hydrogen were char-acterized by X-ray diffraction,scanning electron microscopy and transmission electron *** cast specimens contain CeMg_(12),Mg and Mg_(2)Ni phases,and the increase in Ni content results in an obvious growth of Mg_(2)Ni *** isothermal and non-isothermal hydrogenation and dehydrogenation kinetics of the experimental specimens were investi-gated using the Sievert apparatus,differential scanning calorimetry and thermal gravimetric *** activation energy may be calculated using the Arrhenius and Kissinger *** experimental alloys have been shown to have good activation properties,with a reversible hydriding and dehydriding capacities of around 5.0 wt.%in the first *** initial dehydrogenation temperature of MgH_(2) decreases from 557.5 to 537.7 K with changing Ni content from 5 to 15 at.%.The dehydrogenation activation energy also reduces from 77.09 to 62.96 kJ/mol,which explains the improved hydrogen storage performance caused by Ni *** can be shown that the impact of Ni on the decomposition enthalpy of MgH_(2) is quite modest,with the absolute enthalpy(ΔHr)only decreasing from 78.48 to 76.15 kJ/mol.

关键词： Mg-based alloy Ni content Hydrogen storage kinetics thermodynamic property Activation energy

Effects of Calcium Ions on thermodynamic Properties of Mixed Bilirubin/Cholesterol Monolayers

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Chinese Journal of Chemical Physics 2008年第2期21卷 156-162页

作者： Qiong Wu Yu-feng Tang Ye-min Li An-jian Xie Yu-hua Shen Jin-miao Zhu Chuan-hao Li Department of Science and Technology Anqing Teachers College Anqing 246011 China School of Chemistry and Chemical Engineering Anhui University Hefei 230039 China

The mixed monolayer behavior of bilirubin/cholesterol was studied through surface pressure-area （π-A） isotherms on aqueous solutions containing various concentrations of calcium ions. Based on the data of π-A isotherms, the mean area per molecule, collapse pressure, surface compressibility modulus, excess molecular areas, free energy of mixing, and excess free energy of mixing of the monolayers on different subphases were calculated. The results show an expansion in the structure of the mixed monolayer with Ca^2＋ in subphase, and non-ideal mixing of the components at the air/water interface is observed with positive deviation from the additivity rule in the excess molecular areas. The miscibility between the components is weakened with the increase of concentration of Ca^2＋ in subphase. The facts indicate the presence of coordination between Ca^2＋ and the two components. The mixed monolayer, in which the molar ratio of bilirubin to cholesterol is 3：2, is more stable from a thermodynamic point of view on pure water. But the stable 3：2 stoichiometry complex is destroyed with the increase of the concentration of Ca^2＋ in subphase. Otherwise, the mixed monolayers have more thermodynamic stability at lower surface pressure on Ca^2＋ subphase.

关键词： Bilirubin/cholesterol Mixed monolayer Calcium ion thermodynamic property Air/water interface

Substituent Effect on Infrared Spectra and thermodynamic Properties of Polynitroamino Substituted Cyclopentane and Cyclohexane

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Chinese Journal of Chemical Physics 2008年第6期21卷 526-534页

作者： Ling Qiu Xue-dong Gong He-ming Xiao Institute for Computation in Molecular and Material Science School of Chemical Engineering Nanfing University of Science and Technology Nanjing 210094 China Key Laboratory of Nuclear Medicine Ministry of Health Jiangsu Institute of Nuclear Medicine Wuxi 214063 China

Density functional theory method was employed to study the effect of the nitroamino group as a substituent in cyclopentane and cyclohexane, which usually construct polycyclic or caged nitramines. Based on the optimized molecular structures of two groups of monocyclic nitramines at the B3LYP/6-31G^＊＊ level, the infrared （IR） spectra were obtained and assigned by harmonic vibrational analysis. The calculated results agree reasonably with the available experimental data. According to the principles of statistic thermodynamics, thermodynamic properties were derived from the IR spectra, which were linearly correlated with the number of nitroamino groups as well as the temperature. The contributions of nitroamino groups to thermodynamic properties are in accord with the group additivity.

关键词： Density functional theory Substituent effect Monocyclic nitramine Infrared spectrum thermodynamic property

thermodynamic properties and heat capacity of Ru metal in HCP,FCC,BCC and liquid state

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Transactions of Nonferrous Metals Society of China 2010年第10期20卷 1950-1956页

作者：彭红建周姣连谢佑卿 School of Chemistry and Chemical Engineering Central South University School of Materials Science and Engineering Central South University

Isometric heat capacity cv and isobar heat capacity cp of Ru metal in HCP,FCC,BCC and liquid state were calculated by using pure element systematic *** results are in good agreement with joint army-navy-air force(JANAF) experimental value and the calculation result by first-principle(FP) *** the results have great differences in contrast to Scientific Group Thermodata Europe(SGTE) *** cause is found that it cannot neglect the electron devotion to heat capacity to adjust cp in one-atom(OA) *** disparity between OA method and SGTE database was *** main cause is that OA method adopts the crosspoint with iso-Ec-line and iso-a-line in hybritriangle to determine the properties,but SGTE database is obtained by extrapolation from activity measurements and critical assessment of data from a large number of binary *** properties of Ru metal in HCP,FCC,BCC and liquid state,such as entropy S,enthalpy H and Gibbs energy G were ***,the full description of thermodynamic properties from 0 K to random temperature is implemented.

关键词： Ru metal heat capacity thermodynamic property OA method

Analyses of surrogate models for calculating thermophysical properties of aviation kerosene RP-3 at supercritical pressures

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Science China(Technological Sciences) 2015年第3期58卷 510-518页

作者： XU KeKe MENG Hua School of Aeronautics and Astronautics Zhejiang University

Aviation kerosene is commonly used in combustion and regenerative engine cooling processes in propulsion and power-generation systems,including rocket,scramjet,and advanced gas turbine *** this paper,many surrogate models proposed in the open literature are examined for their applicability and accuracy in calculating thermodynamic and transport properties of the China aviation kerosene RP-3 at supercritical pressures,based on the extended corresponding-states *** enthalpy change from endothermic decomposition and low heating value from combustion of the jet fuel are also *** from a number of simple and representative surrogate models,which contain species components ranging from 1 to10,are analyzed in *** analyses indicate that a surrogate model with four species is the best choice for thermophysical property calculations under the tested conditions,with fluid temperature up to 650 K at various supercritical *** surrogate model is particularly accurate in predicting the pseudo-critical temperature of aviation kerosene RP-3 at a supercritical pressure.A simple surrogate model containing the n-decane species and a surrogate model containing 10 species are the other two acceptable *** work conducted herein is of practical importance for theoretical analyses and numerical simulations of various physicochemical processes at engine operating conditions.

关键词： thermodynamic property transport property hydrocarbon fuel combustion heat transfer pyrolysis

Thermal storage properties of Mg with synergistic effect of LaNi and TiH_(2)

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Rare Metals 2023年第5期42卷 1743-1751页

作者： Qi Wan Li-Jun Jiang Zhi-Nian Li Yang Yang Shu-Mao Wang Xiao-Peng Liu Energy Material and Technology Research Institute General Research Institute for Nonferrous MetalsBeijing100088China

The effect of LaNi and Ti on thermal storage properties of MgH_(2)was *** thermal storage performances of Mg are significantly improved by adding LaNi and *** pressure-composition-temperature(PCT)curves indicate that the formation enthalpy for Mg-15 wt%Ti-5 wt%LaNi sample is 73.00 kJ·mol^(-1),which approaches to the theoretical values of pure MgH_(2).The isothermal measurement indicates that,for the Mg-15wt%Ti-5 wt%LaNi,the first absorption reaction fraction within 2 min is 93.77%,increasing by 0.32%,0.24%and0.08%compared with those for Mg,Mg-5 wt%LaNi and Mg-15 wt%Ti,*** first desorption reaction fraction within 2 min is 73.18%,increasing by 55.91%,9.79%and 8.12%compared with those for Mg,Mg-5wt%LaNi and Mg-15 wt%Ti,***,Mg-15 wt%Ti-5 wt%LaNi has the best cyclic stability in all the *** thermal storage performances of Mg by adding both LaNi and Ti are improved mainly ascribed to synergistic effect of in situ formed La_(4)H_(12.19),Mg_(2)NiH_(4),H_(0.3)Mg_(2)Ni and TiH_(2)particles during cyclic *** above analysis demonstrates that Mg-15 wt%Ti-5wt%LaNi is suitable for using as a heat storage material.

关键词： Thermal storage Magnesium hydride thermodynamic property Kinetics performances Cyclic stability

thermodynamic properties of 3C-SiC

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Chinese Physics B 2013年第10期22卷 429-435页

作者： B.Y.Thakore S.G.Khambholja A.Y.Vahora N.K.Bhatt A.R.Jani Department of Physics Sardar Patel UniversityVallabh Vidyanagar388120GujaratIndia Indus University Ahmedabad 380001GujaratIndia

In the present paper, we report on the results of various thermodynamic properties of 3C-SiC at high pressure and temperature using first principles calculations. We use the plane-wave pseudopotential density functional theory as im- plemented in Quantum ESPRESSO code for calculating various cohesive properties in ambient condition. Further, ionic motion at a finite temperature is taken into account using the quasiharmonic Debye model. The calculated thermody- namic properties, phonon dispersion curves, and phonon densities of states at different temperatures and structural phase transitions at high pressures are found to be in good agreement with experimental and other theoretical results.

关键词： phase transition phonon dispersion curve Debye model thermodynamic property