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relative stability of Boiling of FC-72 and HFE-7100 with Applications toElectronic Device Cooling

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Journal of Thermal Science 2000年第4期9卷 352-355页

作者： Z.W.LIU X.F.PENG 等 DepartmentofChemicalEngineering NationalTaiwanUniversityTaipei10617TaiwanChina DepartmentofThermalEngineering TsinghuaUniversityBeijing100084China

This paper investigates the relative stability between nucleate and film boiling modes of FC-72 and HFE-7100, which have potential to electronic device cooling applications. Equilibrium heat flux, qc, which refers to as an index for measuring the relative stability of boiling, was obtained at a liquid subcooling of 0-20 K. Experimental results reveal that (1) qc increases with liquid subcooling; (2) although the FC-72 exhibits a higher critical heat flux (CHF) than does the HFE-7100, somewhat unexpectedly, the equilibrium heat flux for the latter is greater than the former. Restated, at a prescribed heat flux, the risk to burnout for boiling of FC-72 is higher than that of HFE-7100. The shift in boiling curves interprets the experimental findings.

关键词： boiling relative stability FC-72 HFE-7100 subcooling.

Density Functional Study on Structures and relative stability of Gd（H2O）n^3＋（n=8,9）

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Chinese Journal of Chemical Physics 2009年第4期22卷 395-400,448页

作者：肖伟夏琼琼章永凡宁利新崔执凤安徽师范大学物理系芜湖241000 福州大学化学系福州350002

Density functional theory calculations were performed to study the structures and relative stability of the gadolinium complexes, Gd（H2O）n^3＋（n=8,9）, in vacuo and in aqueous solution. The polarizable continuum model with various radii for the solute cavity was used to study the relative stability in aqueous solution. The calculated molecular geometries for n=8 and 9 obtained in vacuo are consistent with those observed in experiments. It was found that while the nona-aqua complex is favored in the gas phase, in aqueous solution the octa-aqua conformation is preferred. This result, independent of the types of cavities employed, is in agreement with the experimental observation. The reliability of the present calculation was also addressed by comparing the calculated and experimental free energy of hydration, which revealed that the UA0, UAHF, and UAKS cavities are most appropriate when only the first solvation shell is treated explicitly.

关键词： Density functional theory Gadolinium hydrate relative stability Polarizable continuum model Solute cavity

Studies of Thermodynamic Properties and relative stability of Polybrominated Xanthones by Density Functional Theory

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Chinese Journal of Structural Chemistry 2010年第2期29卷 225-232页

作者：单刚李秀菊王遵尧杨郭英 State Key Laboratory of Pollution Control and Resources Reuse Department of EnvironmentNanjing University Department of Environmental Engineering Jiangxi University of Science and Technology Department of Biological and Chemical Engineering Jiaxing University

The thermodynamic properties of xanthone（XTH） and 135 polybrominated xanthones（PBXTHs） in the standard state have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 *** isodesmic reactions were designed to calculate the standard enthalpy of formation（△fHθ） and standard free energy of formation（△fGθ） of PBXTH *** relations of these thermodynamic parameters with the number and position of Br atom substitution（NPBS） were discussed,and it was found that there exist high correlation between thermodynamic parameters（entropy（Sθ）,△fHθ and △fGθ） and *** to the relative magnitude of their △fGθ,the relative stability order of PBXTH congeners was theoretically *** relative rate constants of formation reactions of PBXTH congeners were calculated,Moreover,the values of molar heat capacity at constant pressure（Cp,m） from 200 to 1000 K for PBXTH congeners were also calculated,and the temperature dependence relation of them was obtained,suggesting very good relationships between Cp,m and temperature（T,T^1 and T^2） for almost all PBXTH congeners.

关键词： polybrominated xanthone the number and position of Br atom substitution(NPBS) thermodynamic property relative stability molar heat capacity at constant pressure(Cp m)

Weak Finite Determinacy of relative Map-Germs

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Chinese Annals of Mathematics,Series B 2014年第6期35卷 991-1000页

作者： Changmei SHI Donghe PEI School of Mathematics and Statistics Northeast Normal University School of Mathematics and Computer Science Guizhou Normal College

The weak finite determinacy of relative map-germs is studied. The authors first give the concept of weak finite determination, and then give several sufficient conditions for a relative map-germ to be weak finitely determined, which is an important complement to Mather＇s work. Moreover, us an application, it is proven that the relative stable map-germs are weak finitely determined.

关键词： relative map-germs Weak finite determinacy relative stability

Gas Phase Thermodynamic Properties of Polychlorinated Xanthones Predicted with DFT Method and Cl Substituted Position

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Chinese Journal of Chemical Engineering 2010年第3期18卷 462-471页

作者：陈建挺刘辉费艾莉程维明王遵尧 State Key Laboratory of Pollution Control and Resources Reuse School of Environment Nanjing University Nanjing 210093 China School of Environmental and Safety Engineering Jiangsu Polytechnic University Changzhou 213164 China School of Biological and Chemical Engineering Jiaxing University Jiaxing 314001 China U.S. Fulbright Student Grantee School of Social and Behavioral Sciences Nanjing University Nanjing 210093 China Chery Automobile Co. Ltd Wuhu 214006 China

The gas phase thermodynamic properties of 135 polychlorinated xanthones(PCXTs)are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G***** is found that the chlorine substitution pattern strongly influences the thermodynamic properties of the *** thermodynamic properties of congeners with the same number of chlorines also depend on the chlorine substitution pattern,especially for ortho-substituted *** congeners with one phenyl ring fully chlorinated are found to be the least stable among the *** effect of the chlorine substitution pattern is quantitatively studied by considering the number and position of Cl atom substitution(NPCS).The results show that the NPCS model may be used to predict the thermodynamic properties for all 135 PCXT congeners. In addition,the values of molar heat capacities at constant pressure(cp,m)from 200 to 1000 K for PCXT congeners are calculated,and the temperature dependence relation of this parameter is obtained using the least-squares method.

关键词： polychlorinated xanthones density functional theory number and position of Cl atom substitution thermodynamic property relative stability

Thermodynamic Properties for Polybrominated Dibenzothiophenes by Density Functional Theory

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Chinese Journal of Chemical Engineering 2009年第6期17卷 999-1008页

作者：李加友柳红霞于红霞王遵尧王连生 School of Biological and Chemical Engineering Jiaxing University Jiaxing 314001 China Department of Environment Nanjing University Nanjing 214007 China

The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation （△fH^θ） and the standard Gibbs energy of formation （△fG^θ） of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents （NPBS） are discussed, and it is found that there exist good correlations between othermody namic parameters （including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ） and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure （Cp,m） for PBDT c ongelaers are calculated.

关键词： polybrominated dibenzothiophenes density functional theory method of position of substituted Br atom thermodynamic parameters relative stability

Structural, electronic, and magnetic properties of boron cluster anions doped with aluminum:B_nAl^-(2 ≤ n ≤ 9)

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Chinese Physics B 2012年第4期21卷 199-206页

作者：顾建兵杨向东王怀谦李慧芳 Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China College of Engineering Huaqiao UniversityQuanzhou 362021China

The geometrical structures, relative stabilities, electronic and magnetic properties of small BnAl-（2〈n〈9）clusters are systematicalyy investigated by using the first-principles density functional theory. The results show that the A1 atom prefers to reside either on the outer-side or above the surface, but not in the centre of the clusters in all of the most stable BnAl-（2〈n〈9） isomers and the one excess electron is strong enough to modify the geometries of some specific sizes of the neutral clusters. All the results of the analysis for the fragmentation energies, the second-order difference of energies, and the highest occupied-lowest unoccupied molecular orbital energy gaps show that B4A1- and B8A1- clusters each have a higher relative stability. Especially, the BsA1-cluster has the most enhanced chemical stability. Furthermore, both the local magnetic moments and the total magnetic moments display a pronounced oddeven oscillation with the number of boron atoms, and the magnetic effects arise mainly from the boron atoms except for the B7A1- and BgA1- clusters.

关键词： boron-aluminum cluster geometric structure relative stability density functional the- ory

Studies of Structural and Thermodynamic Properties for Polychlorinated Thianthrenes by Density Functional Theory

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Chinese Journal of Structural Chemistry 2008年第10期27卷 1255-1260页

作者：刘辉孙萍柳红霞王遵尧王连生 School of Biological and Chemical Engineering Jiaxing University State Key Laboratory of Pollution Control and Resources Reuse School of the EnvironmentNanjing University

The structural and thermodynamic （PCTAs） in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G＊ level using Gaussian 98 program. Based on the output data of Gaussian, the isodesmic reactions were designed to calculate standard enthalpy of formation （△fH^θ） and standard free energy of formation （△fH^θ） of PCTAs congeners. The relations of these thermodynamic parameters with the number and position of C1 atom substitution （Npcs） were discussed, and it was found that there exists high correlation between thermodynamic parameters （total energy （TE）, zero-point vibrational energy （ZPE）, thermal correction to energy （Eth）, heat capacity at constant volume （Cv^θ）, entropy （S^θ）, enthalpy （H^θ）, free energy （G^θ）, standard enthalpies of formation （△fH^θ） and standard Gibbs energies of formation （△fG^θ）） and Npcs. On the basis of the relative magnitude of their △fG^θ, the order of relative stability of PCTA congeners was theoretically proposed. In addition, the correlations between structural parameters and Npcs were also discussed. The good correlations were found between molecular average polarizability （α）, energy of the highest occupied molecular orbital （EHOMO）, molecular volume （Vm） and Npcs, and all R^2 values are larger than 0.95. Moreover, it was supposed that the isomer groups with higher toxicity should be Tri-CTA and TCTA.

关键词： polychlorinated thianthrenes density functional theory (DFT) the number and position of CI atom substitution (Npcs) structural and thermodynamic parameters relative stability

Theoretical Studies on the Molecular Structures and Thermodynamic Properties of Polychlorinated Acenaphthylenes

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Chinese Journal of Structural Chemistry 2011年第3期30卷 300-307页

作者：曾小兰张秀兰张义东姜永 College of Chemistry and Chemical Engineering Xinyang Normal University

Geometric structures of 135 polychlorinated acenaphthylene （PCAC） molecules were optimized using density functional theory （DFT） at the B3LYP/6-311G^＊＊ level and some thermodynamic properties of them in the ideal gas state were calculated. The relations of these thermodynamic properties with the number and position of chlorine atoms were also explored, from which the relative stability of PCAC congeners was theoretically proposed according to the magnitude of the relative standard Gibbs free energy of formation （△r,fGθ）. The results show that all PCAC isomers have planar geometric configuration. There exists intramolecular Cl···Cl weak interaction in some PCAC molecules. The change of △fHθ and fGθ of most stable PCAC isomers with increasing the number of chlorine atoms is different from that in the least stable PCAC congeners. The values of fHθ and fGθ for PCAC isomers with the same number of chlorine atoms show a strong dependence on the position of chlorine atoms and the relative stability of PCAC congeners has close relation with the intramolecular Cl···Cl nuclear repulsive interaction.

关键词： polychlorinated acenaphthylenes (PCACs) molecular structures thermodynamicproperties relative stability density functional theory (DFT)