He对低活性Fe-Cr-Mn(W,V)合金辐照产生点缺陷行为的影响

采用超高压电镜与离子加速器相连结的复合辐照装置,研究了注He对低活性Fe-Cr-Mn(W,V)合金辐照产生的点缺陷及二次缺陷行为的影响．实验结果表明：辐照初期形成的点缺陷与He相互作用,进而影响二次缺陷(位错、位错环和空洞)的形成;He明显促进位错密度增大和空洞核心形成,并导致空洞肿胀增加．对辐照产生的点缺陷与He相互作用的机理进行了理论分析。     

Sb,Bi和Fe对Cu-8P共晶合金熔点和组织的影响

采用NETZSCH DSC 404型差示扫描量热仪(DSC)、扫描电子显微镜(SEM)等手段研究了添加元素Sb,Bi和Fe对Cu-8P共晶合金熔点和组织的影响.实验结果表明:Sb,Bi和Fe均能降低Cu-8P合金的熔点.一定量的Sb与Cu,P形成低熔点相,从而大幅降低了Cu-8P合金的熔点,使其熔点降低近200℃;加入少量Bi后,Bi与Cu在共晶团晶界上形成熔点为270℃左右的低熔点化合物,且Bi的加入明显细化Cu-8P合金共晶团,从而使Cu-8P合金的熔点降低;加入Fe能明显细化Cu-8P合金的共晶团,使层片间距由8 μm减为2μm以下,并使共晶团由层片状向短棒状转变,虽然Fe与Cu形成熔点为806℃的高温相,但Fe的细化作用使得Cu-8P合金的熔点降低,但降低幅度不大.同时得出形成低熔点的化合物(相)和细化晶粒是降低合金熔点的有效途径.     

点扩展函数与采样频率及量化精度对图像边缘的影响分析

文章在建立理想边缘成像模型的基础上,分析研究了一般成像系统的点扩展函数与空间采样频率的关系及对图像边缘定位精度的影响,给出了边缘定位误差.同时,还分析研究了量化精度对图像边缘的移位影响,给出了移位误差.最后,给出了本文的分析研究在零件视觉精密检测的应用情况.     

严寒地区围护结构结露及最大允许传热系数

对严寒地区建筑物围护结构结露问题进行了实质性的讨沦,利用室内空气温度和湿度两个参数,在焓湿图上确定了保证建筑物围护结构内表面不出现结露现象的空气状态范围,并在此基础上导出了确定严寒地区围护结构最大允许传热系数的计算公式。     

Aggregation and surface properties of F-specific RNA phages: implication for membrane filtration processes

We report an experimental investigation of the electrokinetic properties and size variations of four F-specific bacteriophages of the types MS2, GA, Qbeta and SP (21-30 nm in diameter) over a broad range of pH values (1.5-7.5) and NaNO3 electrolyte concentrations (1-100 mM). The results obtained by dynamic light scattering show that the aggregation of SP and GA particles takes place over the whole range of pH and ionic strength conditions examined. For MS2 phages, the aggregation of MS2 particles is not observed for pH higher than the isoelectric point (pI) and large ionic strengths for which interparticular repulsive electrostatic interactions are however expected to be sufficiently screened. Aggregation of the MS2 phages, dispersed in 1 and 100 mM electrolyte concentration, occurs at pH 4, which basically corresponds to the pI as determined by electrophoresis measurements. The Qbeta particles suspended in solutions of low electrolyte concentrations aggregate at low pH values (pI approximately 3) and, unlike MS2, at large ionic strengths over the whole range of pH conditions considered in this study. These elements allow the determination of the hydrophobic sequence for the four phages SP approximately GA>Qbeta>MS2. Close inspection of the electrokinetic results reveals small to significant variations of the pI values-depending on the phage considered-with respect to the concentration of indifferent NaNO3 electrolyte. This indicates that features other than chemical and electrostatic in nature play a key role in determining the pI and more generally the electrophoretic mobility mu of viral particles. A qualitative interpretation is given and is based on the consideration of inner electro-osmotic flow within the isolated or aggregated particles. The impact of the flow properties within the particles is further in agreement with recent theoretical formalism developed for the electrokinetics of soft multiplayer particles, the phages analyzed here being some illustrative examples. The determination and qualitative interpretation of the surface properties of the viral particles as reported in the current study are commented within the context of water treatment especially concerning viral removal by membrane filtration processes.     

大型热水热网两级泵中间定压方式

介绍了定压点设置在两级串联循环泵之间的两级泵中间定压补水方式.结合工程实例,对地形复杂的供热系统,比较了采用旁通管定压补水方式、两级泵中间定压补水方式的运行效果,两级串联循环泵中间定压补水方式的效果更好.     

胞状纯铝与胞状铝合金的准静态压缩性能

测量分析了新型轻质、高强度胞状铝合金(ZL111)和胞状纯铝的压缩应力应变σ-ε曲线。结果表明：胞状铝合金的压缩屈服强度以比胞状纯铝高40％以上，其σ-ε曲线呈锯齿状，平台斜率dσ/dε比后者小；胞状铝合金的能量吸收效率峰值和峰宽均大于胞状纯铝，表明胞状铝合金是一种更为优秀的吸能材料。提出了确定泡沫金属材料致密化起始点εD的方法。     

产品形态的两次创新设计方法

产品形态设计两次创新设计方法，以形态创新为目的，针对影响创新形态设计的主要因素，建立一套系统化目标明确的设计流程，以降低不利因素的影响。在两次创新设计方法中，经过第一次创新，获得形态创新点，使产品具有新颖独特的外观形态，在第二次创新过程中，综合应用各种创新思维方法，解决创新形态实现中可能出现的问题与矛盾，以保证其顺利实现，最终获得可行的创新形态方案。并给出了一个应用实例。     

多圆弧凸轮接触点位置的计算机辅助求解

提出了一种简单有效的多圆弧凸轮机构瞬时接触点位置的计算机辅助求解方法,它通过分析凸轮与从动件的瞬时接触公法线与圆弧区域界线之间的相对关系来判断任一瞬时凸轮与从动件的接触点的位置、接触点处的曲率半径和曲率中心的位置,据此,可对凸轮机构进行高副低代和运动分析。该方法对于直动、摆动、尖顶、滚子、平底从动件凸轮机构均适用。应用被建议的方法对含平底摆动从动件圆弧凸轮的多功能家用缝纫机送料机构进行了运动分析及动态仿真,验证了该方法的有效性。     

AUTOMATED IMAGE MATCHING WITH CODED POINTS IN STEREOVISION MEASUREMENT

0 INTRODUCTIONStereovision measurement is a method to retrieve the 3Dgeometry information by using CCD camera to collect multiimages (at least two) of the tested object. During this process,firstly, a series of measuring points need to be created subjec-t…