Equation of State of 20Ne gas in the temperature-range 27–36 K

The many-body phase shifts for ²⁰Ne gas are calculated for low number densities in the temperature-range 27–36?K, using the Galitskii-Migdal-Feynman formalism. These phase shifts are inserted in the Beth-Uhlenbeck formula to determine the quantum second virial coefficient. This is compared to the classical coefficient as well as to the experimental values and other theoretical results. It is used to investigate the pressure-volume-temperature behavior of the gas and to compute other thermodynamic properties – the Helmholtz free energy, total internal energy, entropy, and specific heat capacity – for a number density of 1×?10²⁷ atoms/m³. Our results show that, in cooling and compressing the system, vapor-liquid condensation always occurs.     

第一性原理研究Ni_3Al_(1-x)V_x(x=0-0.4)的力学和热力学性质

采用第一性原理方法研究了Ni_3Al_(1-x)V_x(x=0-0.4)的力学性质,发现当V含量为0.1时,Ni_3Al_(1-x)V_x的块体模量、剪切模量、杨氏模量和硬度都出现极大值,因此V掺杂对于Ni_3Al力学性能的提升具有重要作用.另外,还研究了不同压强下Ni_3Al_(0.9)V_(0.1)的吉布斯自由能、焓、熵、热容等热力学性质随温度的变化关系,结果表明:在高温高压条件下,Ni_3Al_(0.9)V_(0.1)的吉布斯自由能、焓、熵、定压热容都出现明显变化.通过计算Ni_3Al_(0.9)V_(0.1)的体膨胀系数,发现压强对于Ni_3Al_(0.9)V_(0.1)的体膨胀效应具有明显的抑制作用.     

Thermal decomposition kinetics of some transition metal coordination polymers of fumaroyl bis (paramethoxyphenylcarbamide) using DTG/DTA techniques

In the present work, thermal degradation behaviors of the Zn (II), Cd(II), and Hg(II) coordination polymers of fumaroyl bis (paramethoxyphenylcarbamide) (fbpmpc) have been investigated by using thermogravimetric (TG) analysis, differential thermal analysis (DTA) and derivative thermogravimetry (DTG) analysis under non-isothermal conditions in nitrogen atmosphere at multiple heating rates. TG–DTA study noteworthy inferred the presence of lattice water in outer sphere of all the polymers. The decomposition was carried out in three-four well-separated stages where involved the loss of water molecules in the first step followed by organic ligand. Furthermore, the kinetics and thermodynamic stabilities of multi-steps thermal degradation were evaluated. The activation energy (E_a), order of reaction (n), Arrhenius factor (A), enthalpy change (ΔH), entropy change (ΔS) and free energy change (ΔG) of coordination polymers were obtained by using the Coats–Redfern (CR) method. Ultimately, based on initial, half and final decomposition temperature, and kinetics parameters values the orders of thermal stability were estimated.     

Formation of doubly charged atomic ions in the inductively coupled plasma

Experimental and theoretical studies dealing with the formation efficiency of M²⁺ ions, which reduce the analytical signal of M⁺ ions and cause spectral interferences in the inductively coupled plasma mass spectrometry (ICP-MS), have been discussed. Inconsistencies in the results have been pointed out and goals have been formulated for further investigations necessary to correct those spectral interferences. The range of elements that form most readily M²⁺ ions has been determined. Partition functions and reduced thermodynamic potentials of atoms, M⁺ and M²⁺ ions of elements with the lowest second ionization potentials have been calculated. The Saha equation and the thermodynamic simulation were used to calculate the formation efficiency of M⁺ and M²⁺ ions for a selected group of elements in ICP. The results have been compared with experimental and theoretical data available in the literature. The accuracy of the calculations and their applicability to the prediction of the formation efficiency of M⁺ and M²⁺ ions in ICP and other spectral sources has been demonstrated. The main factors responsible for the disagreement between experimental and theoretical values of the formation efficiency of M⁺ and M²⁺ ions have been determined.     

生物质气为燃料的燃料电池理论电动势计算

The electromotive force (e.m.f.) of solid oxide fuel cells using biomass produced gas (BPG) as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2, CO, CO2 and CH4. Compared with using hydrogen as a fuel, the e.m.f.for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition, the optimum amount of H2O to add is determined at various operating temperatures.Further the e.m.f, for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared.The study reveals that when using BPG as fuel, the depression of e.m.f, for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.     

密度泛函理论和从头算方法对四唑负离子的比较研究

运用多种密度泛函理论(DFT)方法和从头算(abinitio)方法研究了四唑负离子的分子几何、电子结构、红外光谱和热力学性质.结果表明,B3LYP-DFT法与MP2-abinitio法计算结果较吻合,故可用于对四唑衍生物及其配合物的系统研究.     

金属钯表面吸附氢同位素的量子力学计算

Based on atomic and molecular reaction statics and group theory, the density functional method (B3P86) with basis sets SDD** for Pd and 6-311G** for H(D and T) have been used, and the ground states of H2(D2,T2) and PdH(PdD,PdT) are derived to be 1Σ+g(D∞v) and 2Σ+(C∞v), respectively, the dissociation energy of H2(D2,T2) and PdH(PdD,PdT) are 4.5918 and 2.6268 eV, respectively. The △Hf°,△Sf°and △Gf° from those reactions and the relationship of the equilibrium pressure with the temperature are obtained. It indicates that these results have good accordance with experimental data.     

荧光光谱法研究萘酚绿B与牛血清白蛋白相互作用特征

在不同温度下,研究了萘酚绿B(NGB)作用于牛血清白蛋白的荧光猝灭光谱、同步荧光光谱、三维荧光光谱和紫外-可见吸收光谱特征。分别用Stern-Volmer方程和Lineweaver-Burk双倒数方程等处理实验数据,证实了在试验浓度和温度范围内,NGB与BSA可相互作用形成复合物, 荧光猝灭作用符合静态猝灭作用特征,作用力主要是疏水作用力和静电作用力;得到了相互作用的相关参数K_LB,ΔHθ,ΔGθ和ΔSθ等的平均值分别为1.411×105 L·mol-1,-5.707 kJ·mol-1,-30.25 kJ·mol-1和79.95 J·K-1,结合位点数为1.258,为研究NGB对蛋白质构象的影响和在生物体内的生物学效应等提供了重要信息。     

巴比妥钠与牛血清白蛋白结合反应的热力学研究

采用荧光光谱研究了药物巴比妥钠(BBTS)和牛血清白蛋白(BSA)的相互作用机理,运用热力学方法确定了巴比妥钠和牛血清白蛋白主要是以静电力相互作用,该过程是一个熵增加、Gibbs自由能降低的自发超分子作用过程,根据Stern-Volmer方程和Lineweaver-Burk双倒数曲线方程求出了其结合常数在高温时比在低温时小,得到巴比妥钠和牛血清白蛋白的结合比为1∶1,证实了巴比妥钠和牛血清白蛋白之间的作用是生成复合物的静态猝灭过程,并且采用同步荧光技术考察了巴比妥钠对牛血清白蛋白氨基酸残基微环境的影响。     

左氧氟沙星与牛血清白蛋白相互作用的液滴荧光法研究

采用液滴荧光技术与紫外-可见光度法研究了生理pH值条件下左氧氟沙星和牛血清白蛋白的相互作用机制。左氧氟沙星对牛血清白蛋白产生荧光猝灭,且猝灭过程是由于复合物形成而引起的静态猝灭。根据Forster偶极-偶极非辐射能量转移理论算出供体-受体的结合距离为2.68 nm。由Linewear-Burk方程求出不同温度下反应时复合物的形成常数K_LB和结合位点数n及对应温度下结合反应的热力学参数,证明二者主要靠疏水作用力结合。同时采用同步荧光分析技术,对蛋白质与药物结合时构象的变化进行了探讨。