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151.
152.
������Һ����CO2����ѧ 总被引:9,自引:0,他引:9
天然气脱除H2S和CO2是天然气净化领域经常遇到的问题。H2S与醇胺的反应属瞬间质子反应,CO2与醇胺的反应则复杂得多,醇胺溶液对H2S的选择性分离主要依靠CO2与醇胺的反应速度差异来实现。文章介绍了伯胺,仲胺,叔胺及空间位阻胺溶液反应的机理和动力学。 相似文献
153.
介绍了基于网络的家电产品故障诊断系统的硬件拓扑结构、软件平台及系统开发。系统在硬件上采用了多种网络平台搭建方式及综合连接技术,软件上采用了IDRS诊断模型和基于事例的最新诊断技术。这也是诊断研究和应用的新领域。 相似文献
154.
A highly linear electrooptic modulator has been designed, fabricated, and evaluated. The design of this modulator consists of only a simple modification to the directional coupler. Two-tone testing has demonstrated that, for an optical modulation depth of 30% per channel, the third-order intermodulation distortion is more than 30 dB lower than that of the conventional directional coupler or Mach-Zehnder modulators. This improvement was not observed to be accompanied by any increase in second harmonic distortion. Also included are results of two-tone computer simulations which predict the improvement in linearity of this device for a range of modulation depths.<> 相似文献
155.
A design-for-testability scheme for detecting CMOS analog faults was reported by Favalli et al. (see ibid., vol.25, no.5, p.1239-46, 1990). The authors propose two alternative designs, one for small circuits and another for large circuits, which require significantly less area overhead (about 1/4 to 1/3) than that of Favalli's design. With the proposed modification in the first design, the untestable problem, which occurred in Favalli's design, can be alleviated. Furthermore, the proposed schemes are also fit to be implemented in VLSI circuits 相似文献
156.
The authors derive and verify the concept of antenna focusing by a planar 'microstrip reflectarray' antenna. Experimental results from schematically distributed patch radiators with microstrip delay lines are consistent with the simulation results. The advantages and disadvantages of such an antenna are described. The measured overall antenna efficiency is approximately 48% at scan angles up to 30 degrees . These results demonstrate the feasibility of such an antenna.<> 相似文献
157.
Chang E.Y. Dean R. Proctor J. Elmer R. Pande K. 《Semiconductor Manufacturing, IEEE Transactions on》1991,4(1):66-68
A dicing process for GaAs MMIC (monolithic microwave integrated circuit) wafers using spin-on wax for wafer mounting and a hybrid process of wet chemical etching/mechanical sawing for chip dicing is described. This process minimizes ragged chip edges and reduces generation of microcracks in addition to the elimination of the plated gold burrs on the backside of the diced MMIC chips. This process gives a uniformity of -3 μm across a 2-in wafer following the completion of the whole backside process. This GaAs chip dicing technique is amenable to production because it exhibits both a very high chip yield (>90%) and nearly flawless edges 相似文献
158.
四论注入光敏器件的物理基础 总被引:2,自引:2,他引:0
叙述了从现象的发现到理论分析,然后用实验进行验证,最后利用这个现象研制成注入光敏器件的全过程,从而证明注入光敏器件有牢靠的物理基础。本文还分析了文献(1 ̄5,10)中的几个主要不同论点及欠妥的讨论方法。 相似文献
159.
To study the effect of ischemia reperfusion injury on microvascular reactivity and tissue metabolism in skeletal muscle, a Sprague-Dawley rat cremaster muscle was prepared as a tourniquet ischemia model and subjected to 2 hr ischemia followed by 1 hr reperfusion to simulate the timing of ischemia during microvascular surgery. The dose-response curve of arteriolar reactivity to norepinephrine, lipid peroxidation, and ultrastructure of capillaries was determined in both the control and postischemic reperfusion stages. Judging from the results, we summarize our observations as follows: (1) Postischemic reperfusion significantly increased arteriolar reactivity to norepinephrine, in which the EC50 for vasoconstriction decreased in all three orders of arterioles. These results suggest that reperfusion could have impaired the vasodilation control mechanism, possibly being endothelium dependent. (2) Lipid peroxidation increased sixfold in the reperfusion group, suggesting that oxygen free radicals have produced significant tissue damage under the created conditions. (3) Significant endothelial damage in the capillaries shown by electron microscope observation supports these studies, indicating that ischemia/reperfusion in clinically transplanted skeletal muscles could cause significant damage to the tissue microcirculation both physiologically and metabolically. 相似文献
160.