显示器件用液晶材料及其特性

由于向列相液晶的单轴光学性质并具有相当低的粘度而被广泛应用于显示器件。已合成多种类型液晶化合物,并采取多种液晶化合物混合配方,从而获得了实用的显示器件液晶材料。本文综述用于显示器件的向列相液晶材料的发展和类型,着重介绍近年来开发的新型材料,并对其特性进行分析和评价。     

四频差动激光陀螺中差分损耗的探讨

理论分析了四频差动激光陀螺中由于镜片的Ｓ－Ｐ相位和Ｑ的各向异性及光束不过水晶片光轴等因素所引起的左、右旋偏振模式间的差分损耗。这种差分损耗会导致激光陀螺中零漂的形成。这一问题的研究对陀螺性能的改进具有重要的参考价值     

Sub-Wavelength Virtual Imaging Using a Pair of 2-D L Loaded and C Loaded Transmission-Line Metamaterial Slabs

The dispersion relations and impedance expressions for both two-dimensional （2-D）/μ-negative and e-negative transmission line metamaterials, which may be paired to form a virtual image of the object, are presented. Under the conjugate matched condition, the voltage distri-butions inside and outside such paired slabs are derived for a plane-wave excitation. Green＇s functions corresponding to the voltages by a y directed elementary current source excitation are utilized to computed voltage phase and mag-nitude in all regions. The 2-D plots show that the voltage waves, the propagating waves and the evanescent waves, can pass through the conjugate matched slabs and so sub-wavelength virtual imaging has been achieved.     

EFFECT OF INCORPORATING ADDITIONAL OLEIC ACID INTO THE PLASMA MEMBRANE OF BAKER'S YEAST ON THE PERMEATION OF PYRUVIC ACID

Addition of Tween 80 to the growth medium of baker's yeast (Saccharomyces cerevisiae) under anaerobic conditions resulted in an increased content of 9-cis-octadecenoic acid (oleic acid) in a membrane preparation consisting mainly of plasma membrane. There was no significant effect on the pyruvate decarboxylation capacity of disintegrated cells, but that of intact cells was significantly enhanced, presumably because of an oleate-induced increase in the permeability of the plasma membrane to pyruvate.     

土石坝应用土工膜防渗设计的几个问题

本文就土石坝应用土工膜进行坝体防渗，对其透水性及渗漏量、土工膜防渗层与坝体间的作用、土工膜厚度的计算方法作了介绍，可供土石坝应用土工膜防渗设计参考。     

可调谐双耦合场作用下的电磁诱导负折射特性

建立了可调谐双耦合场作用下的A型四能级系统模型,研究了系统的介电常数和磁导率随耦合场参数的变化规律,并由此探讨了满足负折射的条件.结果表明,固定耦合场的拉比频率,当两个耦合场中的一个共振、另一个失谐,或两个耦合场均失谐时满足负折射条件,但它们呈现不同的负折射特性.     

Magnetic anisotropy in (Ga,Mn)As on GaAs(1 1 3)As studied by magnetotransport and ferromagnetic resonance

The magnetic anisotropy of a 40-nm-thick (Ga,Mn)As film with 5% Mn grown on GaAs(1 1 3)A is studied by means of magnetotransport and ferromagnetic resonance (FMR) spectroscopy. In addition to the cubic and a weak uniaxial in-plane anisotropy, two uniaxial out-of-plane contributions along [1 1 3] and [0 0 1] are found. Using the anisotropy parameters determined from FMR, the longitudinal and transverse resistivities measured as a function of magnetic field orientation and strength are well modelled within the framework of a single ferromagnetic domain. In particular, the low-field data which are strongly affected by sudden jumps of the magnetization are well reproduced.     

Review: Modified Atmosphere Packaging and its effects on the microbiological quality and safety of produce

Modified Atmosphere Packaging and related technologies are increasingly used to extend shelf-life of fresh produce. This paper reviews the effect of such technology on the spoilage microbiological flora and food-borne pathogens which may be present in produce and also on the organoleptic properties of the product.     

柔性有机发光器件封装材料气体渗透率的质谱法测量

柔性有机电致发光器件(FOLED)封装材料的研究已成为目前国内外FOLED研究的热点。如何测量水蒸汽、氧气和其他活性气体对FOLED封装材料的渗透率, 是FOLED封装材料研究的一个重要课题。提出用质谱分析技术解决柔性有机电致发光器件封装材料气体渗透率的测量问题, 建立了一个封装材料渗透率的质谱法测量系统。介绍了该系统的原理, 利用该系统测量了水蒸汽、氧气和二氧化碳等气体对PET塑料, 以及水蒸汽对ITO薄膜、银薄膜等材料的渗透率。所获得的实验结果与其他文献报道的数据进行了比较, 证明质谱法测量的结果是可信的。     

[110]晶向近本征硅单晶双光子吸收各向异性

以沿[110]晶向切割的近本征硅单晶为样品,通过研究样品对连续波固体激光器所产生的1.3μm的近红外光的双光子吸收所诱导的光电流对入射光偏振方向的依赖关系,研究了双光子吸收的各向异性.测得了硅单晶对该波长的光的三阶极化率张量χ(3)的各向异性系数为-0.25,两个独立分量的比值χxxxx/χxxyy的幅度为2.4,并基于前期工作所得的χxxyy的结果,进而确定了另一分量χxxxx的值大约为1.49×10-19m2/V2.