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   270篇
  免费   22篇
化学工业   114篇
金属工艺   2篇
机械仪表   3篇
建筑科学   7篇
能源动力   6篇
轻工业   30篇
水利工程   1篇
石油天然气   1篇
无线电   18篇
一般工业技术   38篇
冶金工业   33篇
原子能技术   1篇
自动化技术   38篇
  2023年   8篇
  2022年   27篇
  2021年   26篇
  2020年   16篇
  2019年   10篇
  2018年   7篇
  2017年   8篇
  2016年   11篇
  2015年   6篇
  2014年   9篇
  2013年   19篇
  2012年   19篇
  2011年   18篇
  2010年   14篇
  2009年   12篇
  2008年   12篇
  2007年   5篇
  2006年   9篇
  2005年   2篇
  2004年   7篇
  2003年   4篇
  2002年   8篇
  1999年   1篇
  1998年   1篇
  1997年   2篇
  1996年   3篇
  1994年   3篇
  1993年   3篇
  1992年   3篇
  1990年   1篇
  1989年   4篇
  1987年   2篇
  1986年   3篇
  1985年   1篇
  1984年   3篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
排序方式: 共有292条查询结果,搜索用时 15 毫秒
91.
Field studies have not yet conclusively established how attributions affect adjustment to unanticipated traumatic events. This may be due, in part, to the adoption of several untested assumptions in most prior research. It has usually been assumed that attributional issues are important to people who experience a traumatic event, that such concern is adaptive, and that specific attributions (e.g., self-blame) influence subsequent adjustment. These assumptions were tested with longitudinal data collected over 18 mo from 124 parents whose children died of Sudden Infant Death Syndrome. By 3 wks postloss, 45% of parents were not concerned with attributional issues. These parents were less distressed and less likely to blame themselves or others for the death. Longitudinal analyses did not support the assumption that attributions influence subsequent adjustment. Rather, attributions to oneself or others appear to be symptomatic of distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
92.
Because of the increasing complexity of work in people's lives and the rapid ways in which work is changing, it is likely that all applied psychologists will need greater content knowledge about work to assist clients with issues related to work choice, entry, and adjustment. This article identifies 5 knowledge domains about work that include important information for applied psychologists. These domains are as follows: (a) economics and politics, (b) work structures, (c) globalization, (d) social factors, and (e) technology. These 5 domains are outlined, as are anticipated future trends in work. The implications of these issues for applied psychologists are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
93.
The magneto-electric effect has been studied using 1-ethyl-pyridinium bromide in both the molten state and in solution in water or ethanol. The production of stable, coloured radical cations allows one to observe their movement in the cell. From the results it is possible to establish a relationship between the magneto-electric voltage and the type and behaviour of the electrolyte, to better understand the magneto-electric effect in ionic liquid media and to explain the apparent non-reproducibility of certain results. A Lorentz force causes a deviation in the trajectory of charge carriers. This deviation in current lines produces differences in charge concentration in the cell, particularly between the measurement probes. Thus the physical significance of the observed voltage is different from that of the Hall voltage described for electronic solid conductors.  相似文献   
94.
The efficacy of full-building radiation barriers for use in climate control has been analyzed both analytically and experimentally. The mutually reinforcing results suggest that heat transfer through corrugated metal roofs can be dramatically reduced through the use of inexpensive, highly reflective sheets. The experiments were performed on two types of structures, one with a single metal roof and the other fabricated with a dual-roof system. In both cases, it was found that the radiative barriers provide excellent insulation. The reduction of heat transfer from the roof to the building proper was determined both analytically and through experiment. The excellent agreement between the two solution methods suggest that either technique is sufficient for future use.  相似文献   
95.
96.
The cobalt carbonyl [Co2(CO)8] complex is employed as a useful catalyst for the reduction of tertiary amides to the corresponding tertiary amines using 1,1,3,3‐tetramethyldisiloxane (TMDS) and poly(methylhydrosiloxane) (PMHS) as silane reagents under thermal (100 °C) or photo‐assisted conditions (UV, 350 nm at room temperature). Of particular interest, a low catalytic amount (0.5 mol%) of [Co2(CO)8] is used to perform the reaction with 2.2 equiv. of PMHS at 100 °C for 3 h. This reaction is the first example of a cobalt‐catalyzed hydrosilylation of amides.

  相似文献   

97.
Alpha-synuclein (α-syn) and leucine-rich repeat kinase 2 (LRRK2) play crucial roles in Parkinson’s disease (PD). They may functionally interact to induce the degeneration of dopaminergic (DA) neurons via mechanisms that are not yet fully understood. We previously showed that the C-terminal portion of LRRK2 (ΔLRRK2) with the G2019S mutation (ΔLRRK2G2019S) was sufficient to induce neurodegeneration of DA neurons in vivo, suggesting that mutated LRRK2 induces neurotoxicity through mechanisms that are (i) independent of the N-terminal domains and (ii) “cell-autonomous”. Here, we explored whether ΔLRRK2G2019S could modify α-syn toxicity through these two mechanisms. We used a co-transduction approach in rats with AAV vectors encoding ΔLRRK2G2019S or its “dead” kinase form, ΔLRRK2DK, and human α-syn with the A53T mutation (AAV-α-synA53T). Behavioral and histological evaluations were performed at 6- and 15-weeks post-injection. Results showed that neither form of ΔLRRK2 alone induced the degeneration of neurons at these post-injection time points. By contrast, injection of AAV-α-synA53T alone resulted in motor signs and degeneration of DA neurons. Co-injection of AAV-α-synA53T with AAV-ΔLRRK2G2019S induced DA neuron degeneration that was significantly higher than that induced by AAV-α-synA53T alone or with AAV-ΔLRRK2DK. Thus, mutated α-syn neurotoxicity can be enhanced by the C-terminal domain of LRRK2G2019 alone, through cell-autonomous mechanisms.  相似文献   
98.
99.
An efficient Grignard‐type arylation of aldehydes via aryl C H activation was achieved under mild conditions catalyzed by rhodium. The reaction provides an easy access to a wide variety of benzyl alcohols and can tolerate various functional groups as well as air and water.  相似文献   
100.
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