首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   235篇
  免费   8篇
化学工业   41篇
金属工艺   1篇
机械仪表   2篇
建筑科学   13篇
能源动力   1篇
轻工业   18篇
水利工程   2篇
无线电   15篇
一般工业技术   33篇
冶金工业   88篇
自动化技术   29篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2020年   4篇
  2019年   7篇
  2018年   7篇
  2017年   1篇
  2016年   4篇
  2015年   1篇
  2014年   2篇
  2013年   14篇
  2012年   4篇
  2011年   14篇
  2010年   9篇
  2009年   9篇
  2008年   14篇
  2007年   14篇
  2006年   12篇
  2005年   3篇
  2004年   11篇
  2003年   8篇
  2002年   9篇
  2001年   5篇
  2000年   3篇
  1999年   5篇
  1998年   10篇
  1997年   5篇
  1996年   9篇
  1995年   3篇
  1994年   8篇
  1993年   5篇
  1992年   3篇
  1991年   2篇
  1990年   5篇
  1987年   8篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1980年   1篇
  1977年   4篇
  1976年   1篇
  1975年   1篇
  1972年   1篇
  1967年   1篇
  1966年   3篇
  1965年   1篇
  1964年   1篇
  1963年   1篇
  1962年   1篇
排序方式: 共有243条查询结果,搜索用时 0 毫秒
21.
22.
The Insect Telepresence project combines expertise from the robotics and human-computer interaction communities to create a robot exhibit that enables telepresence in scale. The underlying mission of this work is educational: to promote appreciation for insect life and small-scale complexity through exploration of live insect colonies. In this article we describe the robot hardware and software used to bring students face-to-face with insects. We also summarize the user-centered design process and formal HCI methods used to design and evaluate the Insect Telepresence robot. The complete working exhibit, now installed as a permanent robot-entomology station at the Carnegie Museum of Natural History, is presented in this paper in words and pictures.  相似文献   
23.
We investigated the nature of the effects of memory associations on alcohol use and abuse. First, we determined if effects of memory associations on drinking problems are mediated entirely through the frequency of alcohol consumption or, alternatively, if such effects are more direct. Second, personality traits were assessed to evaluate whether they were confounded with memory association in their effects or whether they might moderate the effects of memory associations on alcohol use and abuse. The results showed that memory association measures directly and independently predicted alcohol consumption; these measures indirectly predicted problems from drinking, including drunk driving. None of the assessed personality variables moderated the predictive effects of memory association. The results are consistent with the view that memory associations influence behavior through cognitive processes that are not affected by personality traits or by cognitions emanating from such traits.  相似文献   
24.
Using a representative sample of television content featuring 2,227 programs across different genres and 18 different channels, the frequency and context of altruistic actions were content analyzed. A social cognitive theory approach was taken to guide the selection of contextual variables. The results showed that 73% of the programs in the sample featured instances of helping/sharing at a rate of 2.92 incidents per hour. Further, the actions were most likely to be initiated by adult White males and many acts were depicted in a humorous, realistic, and rewarding context. In terms of channel differences, shows on children's basic cable featured not only the highest proportion of programs with one or more instances of altruism but also the highest rate per hour (4.02 acts). Differences in contextual features and channel type are discussed in terms of social cognitive theory below.  相似文献   
25.
Garlic supplementation and lipoprotein oxidation susceptibility   总被引:2,自引:0,他引:2  
Interventions which make serum lipoproteins less susceptible to oxidation may be antiatherogenic. The antioxidant properties of garlic which have been demonstratedin vitro led us to investigate the effects of garlic supplements on lipoprotein oxidation susceptibility in humans. Ten healthy volunteers were given 600 mg/d of garlic powder (6 tablets of Kwai®) for two weeks in a placebo-controlled, randomized, double-blind crossover trial. We found that although serum lipid and lipoprotein levels were not lowered in this short time period, theex vivo susceptibility of apolipoprotein B-containing lipoproteins to oxidation was significantly decreased (?34%). Because garlic has been reported to beneficially affect serum lipid levels, platelet function, fibrinolysis and blood pressure, this additional effect of retarding lipoprotein oxidation may contribute to the potential antiatherosclerotic effect of garlic.  相似文献   
26.
Demands for designing prime reliant, energy-efficient, and high-performance thermal barrier coatings (TBCs) in gas turbines have led to a growing interest toward comprehensive microstructural characterization. Here we investigate the novel use of high-energy X-rays for small-angle X-ray scattering (SAXS), together with wide-angle scattering and radiography, for the depth-resolved characterization of TBCs grown by electron beam physical vapor deposition (EB-PVD). The coating microstructure is found to consist of columns perpendicular to the substrate, extending through the thickness, with a [001] growth texture and significant intercolumnar porosity. In addition, overshadowing effects during deposition together with gas entrapment give rise to nanoscale intracolumnar porosity consisting of featherlike and globular pores. Radiography showed an increase in the total porosity, from 15% near the substrate to 25% near the coating surface, which is ascribed to an increase in the intercolumnar spacing at the top of the coating. By contrast, the small-angle scattering studies, which are sensitive to fine features, showed the pore internal surface area to be greatest near the substrate.  相似文献   
27.
The primary goal of the present study was to demonstrate how the technique of confirmatory factor analysis (CFA) could be applied to common measurement issues within the school psychology literature. Specifically, the CFA technique was used to test several alternative factor structures thought to underlie a commonly used measure of exposure to community violence. Data were collected from 242 elementary and middle-school, inner city, African American students. Results illustrate the potential benefits and limitations of applying CFA. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
28.
Peak velocities higher than 40000 cm s-1and domain wall mobilities of the order of 1500 cm s-1Oe-1were measured by the dynamic bubble collapse method in garnet films having an orthorhombic anisotropy. The orthorhombic anisotropy was realized by growing garnet films with positive magnetostriction constants under strong compression on  相似文献   
29.
We report on the fabrication and test of semiconductor cylinder fibers (SCFs). To date, we have used two semiconductors CdTe and CdS. Characterization indicates that the semiconductors survive the fabrication process. A number of fibers of each kind were fabricated with reproducible results  相似文献   
30.
The minimization of the sampling rate necessary to store a signal frequently requires filtering of unwanted higher frequency components in order to avoid aliasing errors. In many physiological situations the desired cutoff frequency is too low to be realized by a practical passive analog filter. In such a case either an active analog filter may be used, or the signal may be initially sampled at a higher rate to avoid aliasing, then numerically filtered in real-time, and the resulting smoothed signal sampled at a lower rate (the effective sampling frequency). The purpose of this communication is to describe the use of a class of low-pass digital filters which we have found useful for this purpose.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号