二甲醚专用状态方程的研究

在对二甲醚实验数据进行文献调研的基础上,运用生物进化优化算法开发了二甲醚的饱和蒸汽压、饱和液密度及饱和汽密度方程和 Helmholtz 状态方程.其中二甲醚的饱和蒸汽压、饱和液密度和饱和汽密度方程的平均绝对偏差分别为 0.50%、0.38%和 0.55%.新的 Helmholtz 状态方程计算密度的偏差在液相区为 0.1%以内,临界点附近为 l%,可以很好地用于工程计算.     

A mass spectrometric study of the vaporization of cerium tribromide under Knudsen and Langmuir conditions

The molecular and ionic vaporization of cerium tribromide from the effusion cell (Knudsen conditions) and the open surface of a CeBr₃ single crystal (Langmuir conditions) were studied by high-temperature mass spectrometry. The CeBr₃ and Ce₂Br₆ molecules and the CeBr₄⁻ and Ce₂Br₇⁻ negative ions were observed as vapor constituents. The partial pressures of the molecules in saturated vapor and the ratio between the vaporization coefficients of monomers and dimers under free vaporization conditions were determined. The enthalpies and the activation energies of sublimation in the form of monomers and dimers were measured. Ion–molecular equilibria with the participation of negative ions were studied. The enthalpies of formation of molecules and ions in the gas phase were obtained.     

Photo-induced Conversion of Furylfulgide Single Crystal Under High Pressures

We have studied pressure effects on single crystal of photochromic furylfulgide for researching the possibility of photo-induced structural change. Pressure dependence of the absorption spectra was investigated up to 8.2 GPa at room temperature. Pressure-induced conversion to C-form molecules was observed at 8.2 GPa in single crystal composed only of E-form molecules, while at 5.7 GPa in single crystal containing small amount of C-form ones. Photochromic reaction was observed under high pressure as well as the ambient pressure. The dependence of absorption intensity due to C-form molecules suggests the possibly of cooperative structural change in furylfulgide single crystal at 5.5 GPa.     

Phthalocyanines as an alternative to soluble polymer-supported platforms in organic synthesis

Some small molecules, such as phthalocyanines, capable of exhibiting greatly enhanced capacities and acting as internal tags, are shown to be effective as replacements for polydisperse polyethylene glycols, in soluble polymer-supported type synthesis of some piperidine and piperazine derivatives.     

氯化锂溶液表面蒸汽压的理论及实验研究

应用经典热力学理论建立了溶液表面蒸汽压的计算模型,获得了氯化锂溶液的表面蒸汽压随温度及浓度的变化规律;建立了氯化锂溶液表面蒸汽压测量实验台,实验测量结果与理论模型完全符合,验证了本文结果的正确性.     

The vapor pressure over a binary ordered ferromagnetic alloy

The saturated vapor pressure over a binary alloy in which both atomic and magnetic ordering can occur has been calculated. The temperature dependence of the pressure exhibits special features at the magnetic and structural transformation points. From a knowledge of the temperature dependence of the vapor pressure in the high-temperature range, a number of physical characteristics of the alloy can be determined experimentally.     

Effect of chlorine on the flame spectra of rare-earth elements

The effect of CHCl₃ vapor on rare-earth metal vapors in an acetylene-air flame has been studied spectroscopically. It has been established that both the molecular spectra of the oxide molecules and the emission spectra of the atoms (Eu, Yb) are weakened in the presence of this vapor. In the case of europium and lutecium, the spectra contain new (chloride molecule) bands. Investigation of the relationship between the emission intensities of the atoms or molecules and the partial pressure of chlorine in the flame suggests that molecules of the MeCl₂ type are formed in the flame.     

Optical Properties of Thin Films of Zinc Phthalocyanines Determined by Spectroscopic Ellipsometry

Optics and Spectroscopy - The optical properties of thin films based on unsubstituted and tetrafluoro-substituted zinc phthalocyanines synthesized by physical vapor deposition are studied within...     

Cd1-xZnxTe晶体退火条件的选择及Zn压对退火晶体质量的影响

采用传统Bridgman方法和加入accelerated crucible rotation technique的Bridgman(缩写为ACRT-B)方法生长的Cd_1-xZn_xTe(x=0.04)晶体中存在有点缺陷、位错、杂质和Te沉淀等缺陷.为了减少甚至消除这些缺陷,必须将生长后的CdZnTe晶片在Cd气氛下退火.从Cd-Te和Cd_0.96Zn_0.04Te的PT相图出发,详细讨论了CdZnTe晶体的气固平衡条件,并 关键词： 1-xZn_xTe')" href="#">Cd_1-xZn_xTe 退火 气-固平衡     

Geometry-dependent electronic properties of highly fluorescent conjugated molecules

We present a combined experimental/theoretical study of the electronic properties of conjugated para-phenylene type molecules under high pressure up to 80 kbar. Pressure is used as a tool to vary the molecular geometry and intermolecular interaction. The influence of the latter two on singlet and triplet excitons as well as polarons is monitored via optical spectroscopy. We have performed band structure calculations for the planar poly(para-phenylene) and calculated the dielectric function. By varying the intermolecular distances and the length of the polymer repeat unit the observed pressure effects can be explained.     

可推算非共沸多元混合物临界区饱和蒸气压的新方程

本文根据混合工质假临界温度的推算式,推导出利用各组分等对比态温度的饱和蒸气压计算混合工质的蒸气压的新方程。推算式中的两个与混合物组成及温度有关的系数,可用非临界区用两点文献值标定．用R401系、R404A和 R407系的三元混合工质的文献值与计算值做了比较,泡点压力和露点压力的推算值的绝对偏差平均值小于1．5％。     

Optical breakdown in a liquid: The slow phase of the dynamics of cavity collapse and a noncontact technique for pressure measurement in a liquid

It is demonstrated that, in the case of optically probing the breakdown region, a pulsed signal is formed due to the acoustic pulses produced by the breakdown and collapse of the cavitation cavity. The measured dependence of the delay time of the second pulse on the hydrostatic pressure in the liquid and the pressure of saturated vapor agrees well with the theoretical dependence corresponding to the hydrodynamic model of the cavity. On the basis of the optical cavitation effect, a technique is proposed for a noncontact measurement of hydrostatic pressure in a liquid enclosed in a sealed cell. The range of applicability of the technique is evaluated.     

异丁烷的饱和蒸汽压方程及饱和液体密度方程研究

1引言臭氧层正以惊人的速度被破坏，但在世界范围内CFC和HCFC用于制冷系统尤其是冰箱的量仍然很高，为了保护环境，迫切需要寻找新的更好的制冷剂。人们在寻找新的性能优良而又无公害制冷剂的过程中，意识到了碳氢化合物的价值。联合国环境规划署制冷技术评估小组称其为“长期的、经得起考验的制冷剂’巾］。本文对其中的异丁烷进行了研究，在分析比较的基础上，给出了异丁烷的新饱和蒸汽压方程和炮和液体密度方程，为进一步研究异丁烷的统一热物性方程提供了条件。2异丁烷的饱和蒸汽压方程2．1常用饱和蒸汽压方程的比较分析表1列出了常…     

Thermophysical properties of binary mixtures of odichlorobenzene and o-chlorophenol with diethyl ether, tetrahydrofuran, cyclohexane and anisole

Measurement of density and viscosity has been used for evaluating derived parameters for binary system of o-dichlorobenzene and o-chlorophenol with diethyl ether, tetrahydrofuran, cyclohexane and anisole at the different temperatures and at atmospheric pressure. From these, excess parameters have been calculated over entire range of composition. The variation of derived parameters as well as the sign and magnitude of corresponding excess functions has been used to investigate the type and extent of interaction between the component molecules of the binary mixture.     

Thermal conductivity and thermal diffusivity of the R134a refrigerant in the liquid state

Thermal conductivity and thermal diffusivity of “ozone-safe” refrigerant R134a in liquid state within the range of temperatures 295.9–354.9 K and pressures from the liquid — vapor equilibrium line up to 4.08 MPa have been studied by high-frequency thermal-wave method. The experimental uncertainties of the temperature, pressure, thermal conductivity and thermal diffusivity measurement errors were estimated to be 0.1 K, 3 kPa, 1.5 and 2.5 %, respectively. Values of thermal conductivity and thermal diffusivity of liquid R134a on saturated line have been calculated. Approximation dependences for thermal conductivity and thermal diffusivity within the whole studied range of temperatures and pressures as well as on the saturated line have been obtained. The work was financially supported by the Russian Foundation for Basic Research (grant No. 07-08-00295-a).     

饱和蒸气压与液面形状的关系

指出了某些教材中关于饱和蒸气压与液面形状关系的微观解释的缺陷，并从能量的观点解释了饱和蒸气压与液面形状的关系。     

Effect of thermal expansion on the heat transfer in hexafluoroethane β-C2F6

Physics of the Solid State - The thermal conductivity of solid hexafluoroethane C2F6 has been investigated by the plane-layer steady-state method under saturated vapor pressure at temperatures...     

Photophysical properties of pyridyloxy phthalocyanine encapsulated in nanoparticles

Two aluminum chloride phthalocyanines with pyridyloxy substitution at α/β positions were synthesized. Their structures were characterized by infrared spectroscopy, proton nuclear magnetic resonance as well as elemental analysis. Tetra-α(β)-(2-pyridyloxy) aluminum chloride phthalocyanines were encapsulated into a diblock copolymer methoxy-poly(ethylene glycol)-block-poly(L-lysine) through a cosolvent method. The morphologies and photophysical properties of phthalocyanines encapsulated in nanoparticles were studied by transmission electron microscope, ultraviolet-visible, and fluorescence spectroscopic methods. The photophysical properties of phthalocyanines encapsulated into nanoparticles exhibited substitution positions dependence. The phthalocyanines with substitution at α positions were found to be an excellent candidate for use as photosensitizers for treatment of cancer by photodynamic therapy.     

Study of Friction between Liquid Crystals and Crystalline Surfaces by Molecular Dynamic Simulations

The lubrication characteristics of liquid crystal (LC) molecules sheared between two crystalline surfaces obtained from molecular dynamics (MD) simulations are reported in this article. We consider a coarse-grained rigid bead-necklace model of the LC molecules confined between two atomic surfaces subject to different shearing velocities. A systematic study shows that the slip length of LC lubrication changes significantly as a function of the LC-surface interaction energy, which can be well described though a theoretical curve. The slip length increases as shear rate increases at high LC-surface interaction energy. However, this trend can not be observed for low interaction energy. The orientation of the LC molecules near the surface is found to be guided by the atomics surfaces. The influence of temperature on the lubrication characteristics is also discussed in this article.     

测量激光聚变靶丸内燃料气体总量的对比状态法

推导了用对比参数表示的平衡蒸汽压力方程和平衡蒸汽密度方程，这些方程适用于D2在临界点以下的行为，计算表明，用对比状态计算露点温度下的蒸汽密度比露点法准确，用BWR方程计算充气压力比用理想气体方程合理。