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本文着重将目前国外比较活跃的几种新型反垣克武器;软杀伤反坦克弹药,末敏弹,反坦克地雷以及智能反坦克子弹药的基本原理,作战效能,装备情况作一介绍,并对其发展方向进行了预测。 相似文献
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采用混合物作工质的J—T节流制冷机 总被引:1,自引:0,他引:1
报告了国内外采用混合物作工质的J一T节流制冷机的实验研究情况。理论计算的两个重要参数(等温节流效应和正常沸点)与这些实验的结果作了对比。另外,给出了工作在不同压力下的一种混合工质及纯氮的焓温图。从理论计算和实验的结果可以看出混合工质J一T节流制冷机比单纯工质的J一T节流制冷机有更大的制冷量和更高的热效率。 相似文献
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We have performed selective area epitaxy (SAE) of CdTe layers grown by molecular beam epitaxy using a shadow mask technique.
This technique was chosen over other SAE techniques due to its simplicity and its compatibility with multiple SAE patterning
steps. Features as small as 50 microns × 50 microns were obtained with sharp, abrupt side walls and flat mesa tops. Separations
between mesas as small as 20 microns were also obtained. Shadowing effects due to the finite thickness of the mask were reduced
by placing the CdTe source in a near normal incidence position. Intimate contact between the mask and the substrate was essential
in order to achieve good pattern definition. 相似文献
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Little is known about whether personality characteristics influence initial attraction. Because adult attachment differences influence a broad range of relationship processes, the authors examined their role in 3 experimental attraction studies. The authors tested four major attraction hypotheses--self similarity, ideal-self similarity, complementarity, and attachment security--and examined both actual and perceptual factors. Replicated analyses across samples, designs, and manipulations showed that actual security and self similarity predicted attraction. With regard to perceptual factors, ideal similarity, self similarity, and security all were significant predictors. Whereas perceptual ideal and self similarity had incremental predictive power, perceptual security's effects were subsumed by perceptual ideal similarity. Perceptual self similarity fully mediated actual attachment similarity effects, whereas ideal similarity was only a partial mediator. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
140.
Humin Cheng Jiming Ma Zhenguo Zhao Di Qiang Yongxiang Li Xi Yao 《Journal of the American Ceramic Society》1992,75(5):1123-1128
A pure, acicular lead titanate (PbTiO3 ) fine powder with a white color has been prepared by hydrothermal synthesis. It is a new phase of PbTiO3 with I 4 symmetry, cell parameters of a = 12.358 Å and b = 14.541 Å, and a density of 6.80 g.cm−3 . The influences of pH (12.5 to 14.4), Pb/Ti ratio (1.0 to 1.6) in the feedstock, reaction temperature (130° to 230°C), time (0.25 to 4 h), starting materials, and additives on the formation of acicular PbTiO3 under hydrothermal conditions have been investigated. The acicular PbTiO3 with I 4 symmetry, referred to as the PX phase, can be converted to the perovskite-type (PE phase) of PbTiO3 at about 605°C while its acicular morphology is essentially unchanged. The preferable conditions for preparing pure acicular PX-phase PbTiO3 are that the pH is 13.0 to 14.0, Pb/Ti ratio is >1.3, reaction temperature is 170° to 200°C, time is 0.5 to 1.0 h, titanium butoxide (Ti[O(CH2 )3 CH3 ]4 ) is the starting material, and poly(vinyl alcohol) is an additive. The acicular grain of the PX phase is usually less than 100 nm in diameter and more than 1000 nm in length. 相似文献