Dependence of Junction Voltage Saturation on Uniformity and Quality of Laser Diode Bars

The dependence of the sinkage at the threshold of the electric derivative curve （IdV/dI-I） on the uniformity and the quality of the laser diode bar is analyzed. By using the equations derived from the equivalent circuits of the bars, the influence of the bar uniformity on the depth of the dip is investigated in theory under certain conditions. Furthermore, the experimental results based on the presented technique indicate that the depth of the dip is interrelated to the uniformity and the quality of the corresponding bar. The present technique can be used conveniently and effectively to measure the laser diode bars in practice.     

两共轴带电圆环的相互作用能和作用力

计算了两共轴均匀带电圆环的相互作用能,并求出它们之间的相互作用力,绘制出电场力的空间分布图,进而讨论了作用力和两圆环半径和中心距离等参量的关系.     

Vapour-to-Liquid Nucleation in Associating Lennard-Jones Fluids with Multiple Association Sites

The excess Helmholtz free energy functional for associating Lennard-Jones （L J） fluid is formulated in terms of a weighted density approximation for short-ranged interactions and a Weeks-Chandler-Andersen approximation for long-range attraction. Within the framework of density functional theory, phase equilibria, vapour-liquid surface tension and vapour-liquid nucleation properties including the density profile, work of formation, excess number of particles and critical supersaturation are investigated for associating LJ fluids with different numbers of association sites （M =1,2, 3, 4） per particle. The influences of association energy and association sites on phase equilibria, surface tension and vapour-liquid nucleation properties are discussed.     

BAYER COUNTER CURRENT SYSTEMS IN COMPARISON WITH CONVENTIONAL CO—CURRENT SYSTEM IN THE FIELD OF WATER TREATMENT

From an economical point of view both the quality of the ion exchange resins and the technology used in the field of industrial water treatment are important for a successful performance.In general,two different technologies have been established on the market:The main differneces between the CO-and counter current technologes will be discussed and data concerning the requirement of chemicals for regeneration and the quality of the deionized water will be opposed.In addition several different varieties of the modern counter current technologies,developed and patented by Bayer AG,will be described and the advantages,depending on the application and the demand on the quality of the deionized water,pointed out .In view of stronger regulations concerning the consumption of regeneration chemicals,and waste water,and also because of the superior quality of the produced water,the market share of counter current technologies will continue to increase world-wide.     

一类数列极限的概率求法

通过建立适当的随机模型,应用概率方法可以确定一类具有复杂结构的数列的极限,本文通过举例说明这种方法的运用     

ICP—AES法中稀土元素间的相互干扰研究

稀土元素的谱线较复杂,相互间存在着不同程度的干扰。本文着重研究了ＩＣＰ－ＡＥＳ法中,它们间的干扰情况,并用几种校正方法进行了比较。     

关于“停走”生成器概率模型中的符合率问题

本文首先建立了“停走”生成器辅出序列的概率模型,给出了“停走”生成器输出序列与其线性移位寄存器序列之间的符合率的计算公式。     

关于导体同绝缘体的相互转变

凝聚态物理学中的一个热门问题是 :导体如何变成绝缘体的 ,而绝缘体又是如何变回去成为导体的 ?这个问题对理论和实用都是极有意义的 .最近 ,美国的科学家报道了他们的实验 :他们用紫外光闪烁照射稀土元素钇和镧的氢化物 ,从而使绝缘体钇和镧的氢化物变成了光亮的导体 .五年前 ,丹麦科学家曾通过加压氢 ,使金属变成绝缘体 ,这些丹麦科学家为了寻找新的超导体 ,研究了金属氢化物ＹＨ2 ,可是没有发现超导性 ,但是却发现了在高压氢的处理下 ,光亮的金属ＹＨ2 薄膜转变成透光的绝缘体ＹＨ3 .最近丹麦科学家参与了美国科学家的工作 ,他们把用钯封…     

高分子单链凝聚成与线团相互穿透的多链凝聚态

高分子单链凝聚态由于链内链结构单元间存在范德化吸引作用,高分子链呈打圈链构象,而多链凝聚态由于链内链单元间的吸引作用被与相互穿透的近邻链的单元间吸引作用所屏蔽,高分子链呈高斯链构象。本文简要介绍单链凝聚态试样的制备方法,单链单晶体、单链玻璃体、溶胀的单链高弹态拉伸等的实验观察,并提出从单链凝聚态到多链凝聚态的转变过程问题,即高分子线团的相互穿透过程,目前还缺少基础了解。     

随机变量及其分布

1.本单元重、难点分析本单元的重点:随机变量分布列的意义,两点分布、二项分布、超几何分布、条件概率、独立重复试验等概念的理解及有关公式的运用.本单元的难点:各种概率分布的判断及应用.