流媒体技术在继续教育平台中的应用

在阐述了流媒体技术的基本原理的基础上，通过对主流技术的分析比较提出了以WindowsMedia为技术支撑，基于组播和点播的流媒体继续教育平台解决方案，并对资源的同步控制和安全策略作简要分析，实现一个功能丰富的继续教育平台．     

Cu（Ⅱ） effect on the conformation of regenerated silk fibroin in dilute aqueous solution

Much attention has been paid to the natural mechanism of silkworm spinning due to the impressive mechanical properties of the natural fibers. In this work, we studied the effect of Cu（Ⅱ） ions on the secondary structure of Bombyx mori regenerated silk fibroin （SF） in dilute solution by circular dichroism （CD）. The results indicate that a given amount of Cu（Ⅱ） induces the SF conformational transition from random coil to β-sheet, however, further addition of Cu（Ⅱ） is unfavorable for this conversion. Meanwhile, the conformational changes induced by Cu（Ⅱ） follow a nucleation-dependent aggregation mechanism, which is similar to that found in Prion protein （PrP） denaturation and Aβ-peptide aggregations, leading to the neurodegenerative disease. This work would help one understand further the natural spinning process of silkworm. Additionally, it would be significant for the study of the nervous system diseases, because silk fibroin, extracted in large amounts from Bombyx mori silkworm gland, could be a proper model to study PrP denaturation and Aβ-peptide aggregations.     

高精度步进压印机热误差的建模分析

为了消除由紫外光曝光所引起的步进压印机的热误差，以提高压印机的套刻对准精度，运用逐步回归分析法选取了压印机上温度测量点的数量，将压印机上布置的温度传感器从15个减少到6个，并建立了压印机温度测量关键点处的温度与压头在x、z方向热误差关系的数学模型．实验结果与模型计算结果的对比分析表明，模型的热误差预测精度在x方向可以达到899／6，而在z方向可以达到939／6．应用表明，该方法是一种在压印机热误差建模中选择温度测量关键点的有效方法，可避免热误差建模过程中的变量耦合问题，从而提高了模型的精确性．     

仿射Weyl群(E～)6的a值5的左胞腔

Coxeter群的胞腔是1979年Kazhdan和Lusztig中定义的，这些胞腔理论在代数群的表示理论中发挥了重要的作用。对一些特殊的情况，胞腔的分类已经明确地给出了，例如，对于秩为2的群参见，对于An^-参见，对于a值4的典范型和或参见.本文利用时俭益的运算算法给出了仿射Weyl群E6^-的a值等于5的所有左胞腔。     

一种高阶有理H-F插值逼近算子(Ⅲ)

本文构造了一类有理Hermite-Fejer插值算子,并给出了该算子和逼近阶。     

A new indolic antiauxin, α-(5,7-dichloroindole-3-)isobutyric acid: its chemical synthesis and biological activity

Summary A new potent antiauxin, -(5,7-dichloroindole-3-)isobutyric acid has been synthesized and shown to inhibit auxin-mediated elongation ofAvena coleoptiles and to stimulate root growth of rice seedlings. Its activity is stronger than -(p-chlorophenoxy)isobutyric acid and is comparable to that of 2,3,5-triiodobenzoic acid, which are typical antiauxins.     

过阻尼振子系统中役使原理与绝热近似的关系及适用条件的探讨——线性情况(Ⅰ)

本文指出,《协同学》中将绝热近似与役使原理等同是不妥的,前者只是后者的特例。为此给出了役使原理的新表述,并探讨两者的关系。由此可将H.Haken的理论推广于非绝热近似的情形。 应用役使原理于过阻尼振子系统中,探讨绝热近似的适用条件,引进高级绝热近似的概念,并探讨其适用条件。由此可见考虑时滞。     

Changes in erythrocyte membrane lipid composition affect the transient decrease in membrane order which accompanies insulin receptor down-regulation

We have recently demonstrated, using electron paramagnetic resonance (EPR) spectroscopy, that insulin receptor internalization in response to insulin incubation (down-regulation) in human erythrocytes is accompanied by a transient decrease in membrane order, as measured by the 2T order parameter. Since membrane lipids play such an important role in receptor internalization, we investigated the possible effects that an alteration of the normally-occurring lipid profile might have on down-regulation and the concomitant transient decrease in membrane order. Consequently, human erythrocytes enriched with cholesterol and erythrocytes from cirrhotic patients were examined, because both of these groups of cells have a higher cholesterol/phospholipid molar ratio (CH/PL) than controls. The 5-nitroxystearate spin label, which inserts into the lipid bilayer of cell membranes, was used to monitor changes in 2T for a 3-h period at 37°C. We report here that both cholesterol-enriched and cirrhotic erythrocytes do not down-regulate, as demonstrated by binding assays, and that they do not show the typical transient decrease in membrane order observed in controls. The results seem to indicate that a more ordered membrane inhibits internalization of the insulin receptor in erythrocytes, and that an increase in membrane disorder is necessary for insulin receptor down-regulation.     

Flow-induced release of adenosine 5′-triphosphate from endothelial cells of the rat mesenteric arterial bed

Adenosine 5-triphosphate (ATP) was released into the perfusate of rat isolated mesenteric arterial beds during each of two consecutive increases in flow. There was no significant difference between the amounts of ATP released on each occasion. Substance P was also released into the perfusate by increased flow, although its release was more variable. Removal of the endothelium of the mesenteric vessels with sodium deoxycholate led to a significant reduction (74%) in the amount of ATP released compared with the release before the endothelium had been removed. This suggests that the ATP released into the mesenteric arterial perfusate during increased flow arises from endothelial cells.     

Bromocriptine-induced removal of endoplasmic membranes from prolactinoma cells

Summary Adenomatous prolactin cells lose 39% of their cytoplasm volume within 7 days after the beginning of bromocriptine treatment. A simultaneous reduction of the rough-surfaced endoplasmic reticulum and the Golgi apparatus occurs. Their membranes are removed by rapid transport along the secretory pathway to the cell surface and to lysosomal destruction.We thank Prof. E. del Pozo, Sandoz Ltd, Basle, for the generous gift of injectable bromocriptine, Prof. E.R. Weibel, Dept. of Anatomy, University of Bern, for his technical advice, Dr U. Helfenstein, Institute of Biostatistics, University of Zürich, for his help in the statistical evaluation of the results and the EMDO-Foundation, Zürich, for financial support.