分压式电阻测量的闭环负反馈方法

提出一种反馈分压式电阻测量方法，给出了两种改进方案，分析了它们的测量误差，指出了减小误差的途径和方法。     

An algebraic method for processing colored images

An 8-valued commutative ring is developed to process colored images. Algebraic operators are defined to perform a number of operations such as the extraction of the primary colors and contours of different colors.     

Direct atomic scale analysis of the distribution of Cu valence states in Cu/γ-Al2O3 catalysts

In this paper, the microstructure of a 1 wt.% Cu/γ-Al₂O₃ catalyst that was reduced in a 4% hydrogen/argon atmosphere at temperatures of 523, 773 and 1073 K, is studied by Z-contrast imaging and electron energy-loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM). Results show that the copper species are well dispersed when the catalyst is reduced below 523 K. At 773 K, separated Cu(I) and Cu(0) species are found existing as ring-like and bulk-like particles. This appears to indicate that the copper has not been reduced to its metallic form due to the interaction between the copper oxide and the support. Large spherical particles having core-shell structures with Cu(I) in the shells and Cu(0) in the cores are generated when the catalyst is reduced at 1073 K. The formation of partially oxidized copper species upon reduction at 1073 K is attributed to the metallic copper interaction with the alumina support. This study also demonstrates that high-spatial resolution Z-contrast imaging and EELS performed simultaneously can provide unique information on the morphology and chemistry of metal species in supported metal catalysts.     

Neue Entwicklungen beim Hohlkatoden‐Gasflusssputtern. New Developments in Hollow Cathode Gas Flow Sputtering

The gas flow sputter technique was invented a few years ago particularly for the inexpensive fabrication of sophisticated ceramic layers. Meanwhile, it has matured and become increasingly powerful. Today it is on the verge of being applied in industrial fabrication processes. The present article gives an overview over the method, its characteristics and the numerous applications.     

俄气南供与天然气利用规划

介绍了俄气南供的供气方案，讨论了天然气的市场调查和价格的确定等问题。     

三元催化转化器中的现象分析与研究

在介绍和分析国内外研究现状的基础上，论述了三元催化转化器中的传递现象及化学反应动力学．探讨了三元催化转化器在暖机过程中有害物质的催化转化模型，并建议采用数学模型的方法对催化器在发动机所有工况下的工作过程进行模拟。     

块状镁基金属玻璃的研究进展

介绍了块状镁基金属玻璃的发展过程及最新的研究进展,着重阐述了块状镁基金属玻璃的几种制备方法及其性能,最后指出了今后块状镁基金属玻璃的研究重点.     

高等级公路桥头跳车的原因与技术处理

对高等级公路产生桥头跳车的原因作了分析 ,从地基土地质、台背填料、路面渗水等方面进行了论述 ,提出技术处理措施 ,并指出只有公路建设、设计、监理部门的严格把关 ,才能有效地避免桥头跳车。     

Novel blood-compatible waterborne polyurethane using chitosan as an extender

A series of novel block polymers of polyurethane (PU) and chitosan have been prepared in two steps. The first step is the preparation of PU prepolymer, obtained from polytetramethylene oxide glycol (PTMO, M_n = 1000), isophrone diisocyanate (IPDI), and 2,2′-dimethylol propionic acid (DMPA), followed by ionizing PU prepolymer with triethylamine (TEA). The second step involves PU chain-extended by water-soluble chitosan of low molecular weight (M_n = 5000) by self-emulsion polymerization method. The sizes of the latex particles, morphology, and copolymer architecture have been characterized by dynamic light scattering (DLS), general tensile test, infrared spectroscopy (IR), surface contact angle measurement, and transmission electron microscopy (TEM). Furthermore, it shows that the addition of chitosan remarkably increases anticoagulative property of PU elastomers confirmed by the recalcification time. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008