H.264变换编码与量化原理分析

详细分析了 H .2 64视频编码标准中的整数变换和量化过程。 H .2 64采用 4× 4整数变换 ,并将尺度调整融合在量化过程中 ,降低变换算法复杂度和减少乘法次数 ,相对于以前的编码标准更加有效     

磁浸没透镜的宽束曲轴像差分析的微分代数方法研究

微分代数是计算机数值分析领域中的一个非常有效的方法,可以实现任意高阶微分的准确计算.本文根据微分代数方法的基本原理,将其引入到磁浸没透镜的宽束曲轴像差的分析计算中,得到了任意阶曲轴像差的微分代数表达式.文中针对轴上磁场具有某种解析表达式的一个实际的磁浸没透镜系统,利用微分代数的曲轴像差分析方法,计算了它的曲轴像差,并给出了全部二阶和三阶几何像差的分布图形.     

NUMERICAL INVESTIGATION ON MUD BED-GENERATION AND IMPACTING A WALL ALONG A SLOPE

In this paper mud was treated as the Bingham fluid. In staggered grids, two-dimensional incompressible Navier-Stokes equations for non-Newtonian fluid was solved by the MAC method. Numerical simulations were conducted on mud bed-generating phenomenon and mud impacting a wall along a slope. The distributions of free surface, pressure and velocity of mud and water were obtained. The results indicate that the computed layer thickness of mud bed almost equals the theoretically predicted value. Because of the differences in constitutive relationship, the distributions of free surface are different for water and mud. The distortion of water free surface is much more complicated.     

垂直磁记录介质薄膜研制的新途径(英文)

本文阐述了铝氧化电沉积法获得磁记录材料的基本原理,研究了铝交流氧化膜中沉积磁性金属及其合金制备垂直磁记录薄膜的新途径,建立了铝交流氧化电沉积法,探讨了氧化膜的结构和磁特性的关系。     

无线局域网安全问题研究

为了提供相当于有线局域网的数据安全,IEEE802.11定义了有线等价保密(WEP)协议。然而,最近的研究发现WEP存在严重的缺陷。介绍了无线局域网存在的安全隐患,分析了WEP的结构以及WEP协议的缺陷以及可能遭受的攻击,并探讨了改进方案。     

深亚微米MOSFET衬底电流的模拟与分析

利用器件模拟手段对深亚微米ＭＯＳＦＥＴ的衬底电流进行了研究和分析，给出了有效的道长度，栅氧厚度，源漏结深，衬底掺杂浓度以及电源电压对深亚微米ＭＯＳＦＥＴ衬底电流的影响，发现电源电压对深亚微米ＭＯＳＦＥＴ的衬底电流有着强烈的影响，热载流子效应随电源电压的降低而迅速减小，当电源电压降低到一定程度时，热载流子效应不再成为影响深亚微米ＭＯＳ电路可靠性的主要问题。     

Measurements and correlation of effect of cosolvents on the solubilities of complex molecules in supercritical carbon dioxide

A new transparent microscale circulation-type high pressure equilibrium cell with on-line sampling was devised. With this apparatus, experimental solubility of molecularly complex species such as steroids (cholesterol, stigmasterol and ergosterol) and fatty acids (palmitic acid and stearic acid) in supercritical carbon dioxide(sc-C0₂) were measured. Also, to find an appropriate substance for enhancing both the polarity and the solubility power of the SC-CO₂ solvent, we arbitrarily selected three polar substances such as acetone, methanol and water and the effect of these cosolvents on the solubility of solutes in SC-CO₂ are examined. The supercritical phase equilibrium data of solute-cosolvent-sc-CO₂ systems were quantitatively correlated using a new equation of state based on the lattice fluid theory incorporated with the concept of multibody interaction. We found that the addition of tracer amount of acetone or methanol to SC-CO₂ enhances the solubility of all solutes about thirty to sixty times when compared with the case of pure sc-CO₂ However, for the case of cosolvent water, no further enhancement of the solubility of solutes was realized. Also, the versatile fittability of the equation of state proposed in this work was demonstrated with the newly measured ternary supercritical equilibrium data.     

水溶性防氧化剂在SMT用印制板上的应用

水溶性的防氧化剂是一种有机可焊性保护剂。其方法是在印制板完全阻焊、字符层的印刷，并经电检之后，通过表面浸渍在裸铜的贴片位或通孔内形成一种耐热性的有机可焊性膜层。这种有机、可焊、耐热的膜层，膜厚可达0.3-0.5mm，其分解的温度可达约300℃，传统的印制板的热风整平法亦无法满足QFP愈来愈密集的需求，同时也无法满足SMD表面平整度的要求，更无法适应PCB薄型化生产。烷基苯并咪唑的OSP法能弥补这项缺陷，因而在PCB业乃至SMT产业中得到了广泛的应用。     

a-Si/poly-Si叠层太阳能电池的空间电荷效应和稳定性分析

基于pin结构的a-Si∶H太阳能电池中的空间电荷效应,讨论了a-Si/poly-Si叠层太阳能电池的稳定性.结果表明,在光照射下,光生空穴俘获造成了a-Si∶H中正空间电荷密度的增加,从而改变了电池内部的电场分布,提高了a-Si∶H薄膜中的电场强度.空间电荷效应不会给a-Si/poly-Si叠层结构中的a-Si∶H薄膜带来准中性区(低场"死层"),也没有发生a-Si/poly-Si叠层太阳能电池的光诱导性能衰退,因而a-Si/poly-Si叠层结构太阳能电池具有较高的稳定性.