用于AIS和GIS断路器的弹簧操作机构——从样机发展到系列产品的工艺保证

引言 越来越激烈的市场竞争引发了人们对不断革新的、性价比高和具有更多功能产品的需求,这种需求对产品设计和整个制造工艺都产生了影响.     

Characterization of microstructural changes in an Al-6.8 wt.% Mg alloy by electrical resistivity measurements

Microstructural changes in an AlMg6.8 alloy after different thermo mechanical (TMT) and sensitization treatments were investigated by electrical resistivity measurements. The electrical resistivity was most affected by the content of Mg solute atoms in the α-Al matrix, due to β-phase precipitation, while contribution of the dislocation density to the resistivity of the AlMg6.8 alloy was less pronounced. The amount and distribution of the β-phase precipitated during sensitization were found to be strongly affected by the microstructure developed under the previously applied TMTs, i.e. by the dislocation density and the primary β-phase particles in the dual (α + β) phase structure. During sensitization of the specimens with a recovered/recrystallized dual (α + β) phase structure, precipitation of randomly distributed, globular β-phase particles occurred. Sensitization of cold deformed and recrystallized single α-Al structures induced β-phase precipitation in the form of a continuous layer along the shear bands/grain boundaries.     

Anwendung der analytischen Größenausschluß-Chromatographie zur Untersuchung des Substratahbaus einer kommerziellen Pektatlyase ausErwinia carotovora

Within the scope of the characterization of a commercial pectate lyase (PAL) the pattern of substrate degradation by that enzyme was investigated with oligogalacturonic acids as well as pectins with various degrees of esterification as substrates. For this purpose an analytical size exclusion chromatographie method (HPSEC) was elaborated in order to evaluate the reaction products of the degraded substrates over the whole range of molecular weight with the main interest lying in the emerging oligogalacturonic acids. The degradation of polygalacturonic acid by PAL was additionally investigated by means of thin-layer chromatography (TLC) and viscosimetry. Furthermore spontaneous depolymerization and deesterification of the substrates occurring under the chosen conditions were examined. The PAL showed to be anendo-enzyme both by means of TLC and HPSEC. Polygalacturonic acid was broken down, mainly generating unsaturated tri- and digalacturonic acid; the corresponding monomer was not found. The mode of cleavage is discussed.     

The pha gene cluster of Rhizobium meliloti involved in pH adaptation and symbiosis encodes a novel type of K+ efflux system

Computer-aided time lapse fluorescence videomicroscopy was used to study single cell migration behavior of human aortic endothelial cells on fibronectin coated substrates of varying protein surface density. The role of receptors alpha5beta1, alpha(v)beta3, and alpha4beta1 in mediating cell adhesion and migration on fibronectin was characterized using integrin specific monoclonal antibodies. Matrix density had a direct effect on controlling the proportion of migrating cells and the directional persistence of cell movement (p<0.01). While there was relatively little influence of fibronectin surface density on absolute migration speed, the ability of endothelial cells to disperse over a surface, as measured by the dispersion coefficient, was biphasic with respect to the surface density of this matrix protein (p<0.005). Both cell speed and the proportion of migrating cells was controlled by alpha4beta1 (p<0.01). However, alpha5beta1 selectively regulated the transformation of stationary cells to those exhibiting motile behavior (p<0.05). Migratory responses on fibronectin were not influenced by blockade of the alpha(v)beta3 receptor. It is noteworthy that cell surface adhesive receptors which control commitment to a motile phenotype are not necessarily the same as those that control migration speed.     

Megacell machine

A general purpose highly parallel cellular processor, called Megacell Machine, has been studied and developed.

This paper presents the architecture of the Megacell Machine, discusses the possibilities of LSI, VLSI, WSI implementation, sketches its programming methodology and programming languages. Some application fields (image processing, matrix operations, finite-element analysis, etc.) and performance data will be mentioned.