Perturbation theory of polar hard Gaussian overlap fluid mixtures

A perturbation theory of polar hard Gaussian overlap fluid mixture is discussed. Explicit analytic expressions for the second and third varial coefficients are given. Numerical results are estimated for the thermodynamic properties of quadrupolar hard Gaussian overlap fluid and fluid mixture. It is found that the excess free energy and internal energy depend on concentrationsc ₁,c ₂, molecular diameter ratioR, shape parameterK and the quadrupole momentsQ*₁,Q*₂.     

固定波长应变量子阱的设计与比较

针对ｌｎＧａＡｓＰ材料，我们比较了不同应变与阱宽组合的固定波长应变量子阱特性压应变下量子阱的应变量越大，阱宽越窄，其能带结构越理想张应变下主要由于电子与轻空穴的偶极矩阵元比电子与重空穴的大，以及其较大的态密度，使得张应变量子阱的微分增益比压应变和匹配量子阱的大得多如果固定的张应变量只能使第一子带为ＬＨ，第二子带为ＨＨ，则存在一个最优的阱宽，阱宽太小不能消除ＬＨＩ与ＨＨ２的耦合，阱宽太大又会带来ＬＨ３与ＨＨ２的耦合，同样会有不利影响     

Development of a novel high speed (electron-mobility) epi-n-ZnO thin films by L-MBE for III–V opto-electronic devices

Intrinsic epitaxial zinc oxide (epi-ZnO) thin films were grown by laser-molecular beam epitaxy (L-MBE), i.e., pulsed laser deposition (PLD) technique using Johnson Matthey “specpure”-grade ZnO pellets. The effects of substrate temperatures on ZnO thin film growth, electrical conductivity (σ), mobility (μ) and carrier concentration (n) were studied. As well as the feasibility of developing high quality conducting oxide thin films was also studied simultaneously. The highest conductivity was found for optimized epi-ZnO thin films is σ=0.06×10³ ohm⁻¹ cm⁻¹ (n-type) (which is almost at the edge of semiconductivity range), carrier density n=0.316×10¹⁹ cm⁻³ and mobility μ=98 cm²/V s. The electrical studies further confirmed the semiconductor characteristics of epi-n-ZnO thin films. The relationship between the optical and electrical properties were also graphically enumerated. The electrical parameter values for the films were calculated, graphically enumerated and tabulated. As a novelty point of view, we have concluded that without doping and annealing, we have obtained optimum electrical conductivity with high optical transparency (95%) for as deposited ZnO thin films using PLD. Also, this is the first time that we have applied PLD made ZnO thin films to iso-, hetero-semiconductor–insulator–semiconductor (SIS) type solar cells as transparent conducting oxide (TCO) window layer. We hope that surely these data be helpful either as a scientific or technical basis in the semiconductor processing.     

BOUNDARY AND CORNER LAYER BEHAVIOR IN SINGULARLY PERTURBED ROBIN BOUNDARY VALUE PROBLEM

This paper is concerned with boundary and corner layer behavior of the singularly perturbed Robin boundary value problem(RP) for the second-order nonlinear differential equations. The existence and asymptotic estimate of solutions of (RP) is discussed by appropriately constructing the bounding functions and using the theory of differential inequality.     

STEFAN PROBLEM WITH NONLINEAR BOUNDARY FLUX AND INTERNAL CONVECTION OF A MATERIAL

A Stefan problem with nonlinear boundary flux and internal convection of a material are considered. The existence, uniqueness and continuous dependence of globally weak solution of this problem are obtained. This paper extends the results of Fahuai Yi and T.M.Shih, relaxes restrictions that does not be to accord with reality very much on internal convection and boundary conditions in their articles.     

薄层流中的一类三阶奇摄动边值问题的渐近分析

本文研究薄层流中出现的一类三阶奇摄动数学模型．本文不采用研究其渐近等价的二阶奇摄动微分方程的方法,而利用边界层函数法,直接讨论该数学模型的渐近解,并严格地证明了解的存在唯一性和其渐近解的一致有效性．本文的结果不仅去掉了以往方法所必须的位势条件,纠正了某个不适定的假设,而且推广了以往的结果．     

纳米光学和生物单分子探测

纳米光学技术展示了纳米级探测本领，同时生物单分子探测所需要分辨尺度也是纳米数量级的，因此在生物单分子探测过程中，纳米光学发挥了巨大的作用．文章介绍了与生物单分子探测技术相关的纳米光学技术，包括量子近场光学探针技术、近场光学成像技术(包括扫描近场光学显微术及全内反射荧光显微术)和激光光钳测控技术及它们在生物单分子探测上的进展，从而在染色、成像、测控三个方面展示了纳米光学技术在生物方面的应用，并对其未来的发展方向进行了展望．     

空调器新型轴流风扇叶尖涡的研究

本文采用Navier-Stokes方程和Spalart-Allmaras湍流模型,对只在叶轮尾缘带有导流罩的低压轴流风扇进行了三维稳态内流模拟,详细分析了叶顶流场中叶尖涡的产生和发展轨迹。研究结果表明,叶尖涡在距叶尖前缘约1/4叶顶轴向弦长的吸力面附近形成,在叶轮出口附近消失,在切向约占3/4流道,近似形成一个涡环,阻塞主流.在回转面上,叶尖涡涡核先沿流线方向发展,在导流罩附近逐渐转为切向方向发展;在径向方向,叶尖涡先沿外径方向发展,在导流罩附近转向内径方向移动。空调室外机系统的不对称结构引起叶尖涡在叶轮旋转过程中的相对位移.流量的变化对叶尖涡的轴向位置影响较大,而对其径向位置的影响不明显;小流量时叶尖涡的轴向移动能力减弱,切向移动能力增强,消失位置向前缘方向移动.     

Effects of shaded facets on the performance of metal-coated etched diffraction grating demultiplexer

A finite-difference time-domain (FDTD) method combined with a periodic boundary condition is used to analyze the diffraction efficiency of an etched diffraction grating (EDG) demultiplexer coated with a metallic film at the backside. The numerical results show that the diffraction loss is mainly due to the scattering effect of shaded facets of a metal-coated grating at both the polarizations. However, the same shaded facets can produce a higher loss for a TM polarization than that for a TE polarization, which induces a higher polarization dependent loss (PDL) of the demultiplexer.