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21.
采用许瓦兹-克里斯托福变换,求得了以椭圆锥为发射体的真空微电子二极管区域的电位分布的解析解。采用自由电子模型,运用WKB近似,对真空微电子二极管的表面势垒和隧道电流进行了理论研究,求得了表面势垒和隧道电流的表达式,并进行了数值计算。 相似文献
22.
通过对淤泥质粘土层地基两种处理方案的效果的比较,提出针对淤泥质粘土层地基进行处理的较理想方案. 相似文献
23.
将吸气罩流场计算区域分成两个子区域,分别推导出各子区域边界积分方程,并将各子区域方程组合成一个方程,利用边界元法进行求解. 相似文献
24.
25.
针对目前实验研究中出现对真空预冷和减压冷藏2种技术的混淆,文中从真空预冷和减压贮藏的基本原理和运
行时系统负荷差异产生的根本原因上对2种技术予以区分。结合不同类型真空泵的使用特点和不足,对减压冷藏系统
的真空部分进行了详细的设计校核。本文提供的设计和校核方法可为减压冷藏装置真空系统的选型设计提供参考。 相似文献
26.
文章通过氧化工艺对真空电弧沉积TiN薄膜组织与性能的影响这一课题研究,指出在毕业论文的工作中,将专业知识运用到实际课题的研究中,有利于提高学生的综合素质. 相似文献
27.
通过对制冷系统中回热器、蒸发器和压缩机工作过程的理论分析以及对蒸发器的热设计,定量地讨论了回热器出入口条件的改变对蒸发器尺寸、压缩机功率以及制冷系统成绩系数等的影响。降低制冷工质在回热器出口处的过热度,可以减小蒸发器的尺寸,但由此带来的不利因素,是需要增制冷工质的质量流量以及提高压缩机的压缩功率。 相似文献
28.
We describe a significant practical consequence of taking anthropic biases into account in deriving predictions for rare stochastic catastrophic events. The risks associated with catastrophes such as asteroidal/cometary impacts, supervolcanic episodes, and explosions of supernovae/gamma‐ray bursts are based on their observed frequencies. As a result, the frequencies of catastrophes that destroy or are otherwise incompatible with the existence of observers are systematically underestimated. We describe the consequences of this anthropic bias for estimation of catastrophic risks, and suggest some directions for future work. 相似文献
29.
通过分析汽车真空助力器及制动主缸结构和工作原理,详细研究有关标准,设计开发出了关于助力器及主缸的综合性能试验台。试验台的开发过程中程序的编制完全采用的是Visual Basic6.0语言。该试验台能满足不同标准下实验方法的要求并能全面准确地体现真空助力器及主缸的各种性能。 相似文献
30.
The aim of this study is to investigate changes in the vascular system and hemodynamics between patients with organic erectile dysfunction (ED) (DM type I and II), as well as to compare the quality of sexual life between those two groups after the treatment with vacuum erection device (VED). Study enrolled 50 males with DM, aged from 35 to 67 years, who have attended the urologic clinic due to inability to attain and maintain an erection of the penis sufficient to permit satisfactory sexual intercourse. Patients were using VED and six months later were assessed for therapy results. The International Index of Erectile Function (IIEF) was used to quantify erectile dysfunction. Alprostadil injection test was also used, with Doppler color flow imaging system, to evaluate the peak systolic velocity (PSV) and diameter of cavernosal artery (DCA). Significantly higher values of PSV were obtained in patients with DM type II. Also, DCA showed significant difference between two groups of patients. There was significant improvement in three items of IIEF after six months of treatment among both groups of examinees. Patients with DM type I had more serious risk for development of arteriogenic ED. VED could be a good alternative therapy for patients who denied peroral therapy. 相似文献