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1.
本文研究了一种硅高频高跨导JFET的设计和制造技术，测量结果表明，所研制的器件性能基本达。到了国际上先进公司同类产品的指标参数。 相似文献
2.
《信阳师范学院学报(哲学社会科学版)》2017,(3):132-135
美国当代著名作家唐·德里罗的小说《白噪音》艺术地再现了后现代美国人的生存环境和生存状态。美国消费社会建构的三个关键领域——媒介影像、消费行为和大众文化,成为美国后现代社会的景观。《白噪音》展示了后现代美国社会的两大消费行为——看电视和购物,同时,揭示了美国大众文化甚至学术研究也趋向商业化。这些异化消费使得人们丧失了主体性,陷入了精神空虚、焦虑、孤独与异化,并导致垃圾激增、环境污染和生态灾难。 相似文献
3.
Ching Yee Choi 《International Journal of Disability, Development & Education》2005,52(4):345-360
Many researchers have stressed that the acoustic environment is crucial to the speech perception, academic performance, attention, and participation of students in classrooms. Classrooms in highly urbanised locations are especially vulnerable to noise, a major influence on the acoustic environment. The purpose of this investigation was to determine noise levels in one such urban environment, Hong Kong. The ambient noise level, and its relationship to the speech intensity levels of both teachers and students was surveyed in 47 primary school classrooms. Moreover, the presence of acoustical treatments for noise reduction and the use of classroom amplification systems were documented for each classroom. The survey found that the mean occupied noise level was 60.74 dB (A); the mean unamplified and amplified speech‐to‐noise ratios of teachers were 13.53 dB and 18.45 dB, respectively; while the mean unamplified speech‐to‐noise ratio for students was 4.13 dB. Most of the classrooms exhibited insufficient acoustical treatments to provide significant noise reduction. The listening environment in many Hong Kong primary schools was not favourable for optimal classroom learning. Recommendations for improving the acoustical environment in classrooms in highly urbanised locations such as Hong Kong are discussed. 相似文献
4.
The term noise is used to describe fluctuations about the mean deterministic stationary value of a physical quantity. It is
now being increasingly realised that noise is an important ingredient to bring order in dynamical processes. Though it appears
counterintuitive, noise seems to help in directing transport processes in biological systems at the molecular level. In Part
2 of the article, we discuss some more examples of noise assisted directed motion. 相似文献
5.
随机共振能将噪声的部分能量通过非线性系统作用转为信号的能量,从而提高输出信号的信噪比,这为解决从强噪声背景中检测提取有用弱信号问题提供了一种全新的思路和方法。将随机共振机制应用于图像复原,可以提高图像复原效果,特别是在处理被强噪声污染的图像信号时。 相似文献
6.
液压齿轮油泵噪声的诊断与控制 总被引：3，自引：0，他引：3
陈文辉 《安徽职业技术学院学报》2005,4(1):21-23
噪声是齿轮油泵常见的故障之一,解决这一故障有利于齿轮油泵正常工作。文章分析了齿轮油泵产生噪声的原因,并根据产生噪声的不同机理找出了有效的解决措施。 相似文献
7.
现代彩色静电照相数字印刷出现以不同半色调算法复制彩色图像的趋势。影响最终印刷图像噪声表现的因素包括数字半色调算法、纸张类型以及墨粉颗粒形状和尺寸的非均匀性等,其中半色调算法决定网点结构,成为本文讨论的重点。 相似文献
8.
基于低碳环保理念,通过分析婴儿车在使用过程中容易忽略的噪声及粉尘问题,采用环保隔音材料,在车体底部安装除尘空调,以太阳能为动力除尘,设计“堡”贝太阳能式降噪除尘婴儿车,以期最大限度降低噪声及粉尘对婴儿的危害。 相似文献
9.
本文从实用的角度，以具有代表性的NEC数字式寻呼机PN3PY系列机为例，说明了在生产或维修时如何对数字寻呼机进行简便有效的指标测试． 相似文献
10.
李艳 《绵阳师范学院学报》2007,26(12):79-82
美国著名当代作家唐.德里罗的小说《白噪音》被喻为"美国死亡之书",小说中的主人公杰克.格拉迪尼的死亡恐惧心理尤为突出,也是文艺理论界研究和心理学界极为关注的焦点之一。本文主要从其恐惧心理的具体表现入手,进而探讨造成这种恐惧心理的各种原因。 相似文献