Bubble Interaction in Thermal Boundary Layers

IntroductionBoiling is often encountered in a wide variety ofapplications,including traditional industrialprocesses,such as metallurgical quenching,flooded tube and shell evaporators,and immersioncooling of industrial components,and modern heattransfer te…     

在聚酯变形工艺中最佳的假捻器入口温度

通过举例说明在聚酯变形工艺中最佳的假捻器入口温度。     

Subcellular localization of several heavy metals of Hg, Cd and Pb in human liver

Liver, as an important metabolic and detoxicological organ of human body, can be used as a good bioindicator for evaluating body burden of environmental pollutants. Its elemental contents and their chemical forms are closely related to the status of human health and disease. In this paper, the liver samples collected from normal subjects were separated to different subcellular fractions of nuclei, mitochondria, lysosome, microsome and cytosol by differential centrifugation. Then their concentrations of heavy metals of As, Pb, Cd, and Hg were determined by atomic absorption and atomic fluorescent spectroscopy. Our results show no significant difference with literature ones when comparing their gross concentrations. In the case of their subcellular distribution, the Hg concentrations are higher in mitochondrial, microsomal and cytosolic fractions; the Cd concentrations are higher in cytosolic and mitochondrial fractions, while As highest in nuclear fraction. The highest concentration of Pb is found in microsomal fraction with similarity to Fe. Mercury in liver is mainly in the form of inorganic, and methylmercury ranged from 9% to 50% with the average value of 20.9% 13.3%. These results indicate that the cellular distribution and the accumulated target organelles are quite different among these heavy metals, which suggest their various pathways and toxic mechanism in vivo.     

全局收敛的多变量极点配置自校正控制算法

提出了一种简单的隐式多变量极点配置自校正控制算法,并证明了该控制算法具有全局收敛特性。仿真实验结果表明该自适应控制方案具有较好的控制性能。     

铋-2-[3,5-二溴-2-吡啶偶氮]-5-二乙氨基苯酚-乳化剂OP的显色反应

研究了在非离子型表面活性剂存在下铋(Ⅲ)与2-[3,5一二溴-2-吡啶偶氮]-5一二乙氨基苯酚的显色反应。在pH～2的酸性介质中,乳化剂OP能使Bi(Ⅲ)-2-[3,5一二溴-2-吡啶偶氮]-5-二乙氨基苯酚络合物增敏,其最大吸收峰位于596nm,摩尔吸光系数为1.05×10~5在乳化剂OP存在时,连续变化法和斜率比法测得络合物的组成比为Bi:R=1:2。此方法用于粗铅和铅板栅合金中Bi的测定获得满意的结果。     

低温烧结PZT压电陶瓷的研究

对ＰＺＴ压电陶瓷的低温烧结进行了研究。实验发现，在ＰＺＴ陶瓷中添加少量低 熔玻璃（ｘＢ２Ｏ３－чＢｉ２Ｏ３－ｚＣｄＯ）可使烧结温度从１２５０℃降低至９６０℃。其性能参数： Ｋｐ≥０．５２～０．５６，Ｑｍ≥１０００，ε３３Ｔ／ε０＝８００～１２００， ｔｇδ≤５×１０－３．借助于扫描电镜 （ＳＥＭ）、电子探针微区分析（ＥＰＭＡ）、Ｘ光光电子能谱分析（ＸＰＳ）和体积烧缩速率的 测量，对陶瓷显微结构、烧结机理和添加剂的作用进行了讨论，所研制的低温烧结瓷料 巳用于制备独石压电陶瓷变压器，其空载交流升压比可高达 ９ ０００以上。     

■~((2))类密度函数在一般核下最近邻估计的一致收敛速度

柴根象在[5]中研究了■类密度函数最近邻密度估计的一致收敛速度,本文将其推广到一般核的情形,得到了同样的结果。     

中子活化分析在秦始皇陵1,3号坑兵马俑原料产地研究中的应用

选取秦始皇陵1号坑兵马俑样品20个,3号坑兵马俑样品44个,秦陵附近黏土样品20个,耀州瓷胎样品2个,进行中子活化分析(NAA),测定每个样品中32种元素的质量含量.将这批NAA数据进行模糊聚类分析,得到动态聚类图.结果表明,1号坑和3号坑兵马俑原料来源不完全相同,但它们都与秦陵附近垆土关系密切,与秦陵附近黄土关系比较疏远,与耀州瓷胎的关系甚远.由此推断秦陵1号坑和3号坑兵马俑的原料可能取自秦陵附近的某些垆土层,烧制兵马俑的窑址可能也在秦始皇陵附近.     

预混可燃气火焰传播速度的研究

采用传动的热力理论,在火焰上建立热能平衡式,该平衡式不仅考虑了新鲜混合气的热焓变化以及反应过来的热量,更进一步了考虑燃烧反应本身的放热率,采用奇异摄动法得到预混丁烷气的流火焰传播速度表达式,并与采用本生灯试验测试系统测得的预混气平均火焰传播速度进行了比较,得到了较为满意的结果。     

8090Al-Li合金δ′相的相界特征

采用小角Ｘ射线散射技术研究８０９０Ａｌ－Ｌｉ合金回火析出δ′相的相界特征．实验结果表明,合金在１６０℃时效时析出的δ′相粒子与基体之间存在过渡界面层,表明δ′相是通过Ｓｐｉｎ－ｏｄａｌ分解机理形成的,而且δ′相粒子平均半径的三次方与回火时间的关系与ＬＳＷ动力学规律不一致