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   228篇
  免费   1篇
电工技术   4篇
综合类   1篇
化学工业   22篇
金属工艺   11篇
机械仪表   6篇
建筑科学   12篇
能源动力   7篇
轻工业   14篇
水利工程   4篇
无线电   9篇
一般工业技术   26篇
冶金工业   82篇
原子能技术   2篇
自动化技术   29篇
  2022年   3篇
  2020年   2篇
  2018年   4篇
  2017年   4篇
  2016年   3篇
  2015年   2篇
  2014年   2篇
  2013年   8篇
  2012年   5篇
  2011年   4篇
  2010年   6篇
  2009年   3篇
  2008年   4篇
  2007年   2篇
  2006年   7篇
  2005年   4篇
  2004年   7篇
  2003年   5篇
  2002年   4篇
  2001年   7篇
  2000年   5篇
  1999年   4篇
  1998年   36篇
  1997年   15篇
  1996年   13篇
  1995年   14篇
  1994年   5篇
  1993年   2篇
  1992年   4篇
  1991年   6篇
  1990年   2篇
  1989年   2篇
  1987年   2篇
  1986年   1篇
  1985年   4篇
  1984年   3篇
  1983年   4篇
  1982年   2篇
  1981年   1篇
  1980年   4篇
  1978年   3篇
  1976年   1篇
  1975年   4篇
  1973年   2篇
  1971年   2篇
  1966年   2篇
排序方式: 共有229条查询结果,搜索用时 15 毫秒
1.
The purpose of this article is to deliberate the moral and legal dilemma entailed in the weapon of the labour strike as a pressure tactic on the Israeli Finance Ministry regarding job slots, budgets and, in effect, violating the collective agreement signed by the nurses and impairing patients' treatment, as opposed to refraining from striking and suffering the heavy burden of work, the lack of trained personnel, low wages, and the inability to give patients proper, high quality treatment.  相似文献   
2.
A 62-year-old female who had a complaint of palpitation was diagnosed as bicuspid aortic stenosis and left single coronary artery by the echocardiographic examination, cardiac catheterization study and coronary artery angiography. Aortic valve replacement was performed and the patient was discharged 22 days after surgery with good post-operative course. Preoperative coronary artery angiography was important in the case of aortic valvular disease.  相似文献   
3.
The twinning of YBa2Cu3O7 (YBCO) thin films with c-axis orientation on (001) MgO, (001) SrTiO3, (012) LaAlO3, (110) NdGaO3 and (001) NdGaO3 substrates, prepared by laser ablation, has been examined using a combination of and θ/2θ scans at a four-circle diffractometer. On all substrates, except for (001) NdGaO3, the tetragonal to orthorhombal phase transition results in four different orientations of YBCO twins relating to the substrate. On (001) NdGaO3 only two different twin orientations, accompanied by a slight lattice monoclinization, has been observed.  相似文献   
4.
The cell division cycle gene CDC15 is essential for the late nuclear division in the yeast Saccharomyces cerevisiae. The amino acid sequence of the 974 amino acids/110 kDa CDC15 gene product, as deduced from the nucleotide sequence, includes an aminoterminal protein kinase domain which contains a primary sequence mosaic showing patterns specific for protein serine/threonine kinases besides those for protein tyrosine kinases. Many protein kinases non-essential for growth are known. CDC15 represents an essential protein kinase like CDC7 and CDC28. A carboxyterminal deletion of 32 amino acids renders the protein inactive.  相似文献   
5.
Friedman Y  Schweitzer N 《Applied optics》1998,37(31):7229-7234
We have studied the stability of systems of plane mirrors by using a new way to describe ray transformations caused by such systems. All stable systems comprising as many as three mirrors are described and classified. Besides the well-known corner cube, infinitely many stable retroreflecting and direction-preserving three-mirror systems have been found.  相似文献   
6.
Virtual teams (VTs) are teams whose members do not share a common workspace all of the time, and must therefore collaborate using communication and collaboration tools such as email, videoconferencing, etc. Although the body of research on VTs is quickly expanding, to date, the field has yet to produce a comprehensive and coherent foundation upon which future research can be based, and empirical findings based on a substantive sample of real VTs remain limited at this time. This study fills a void in the VT literature with respect to defining and operationalizing the construct of degree of virtuality, and responds to calls for research that studies ongoing VTs, under real conditions. Data were collected from 30 VTs working in a Canadian technology‐based organization. Degree of virtuality was defined to include three dimensions: the proportion of work time that the VT members spend working apart (team time worked virtually), the proportion of the team's members who work virtually (member virtuality) and the degree of separation of the team's members (distance virtuality). The VTs in this study were found to have varying degrees of virtuality, and although the three dimensions were not highly intercorrelated, all were found to be significantly correlated to variables that have been previously linked to VT effectiveness. The correlations were all in the expected direction (negative), indicating that higher degrees of virtuality are associated with perceived decreases in the quality of team interactions and performance. The results of this research would suggest that the more that teams move away from the proximate form, the more the traditional measures of team effectiveness are negatively impacted.  相似文献   
7.
Control of smallpox by mass vaccination was one of the most effective public health measures ever employed for eradicating a devastating infectious disease. However, new methods are needed for monitoring smallpox immunity within current vulnerable populations, and for the development of replacement vaccines for use by immunocompromized or low-responding individuals. As a measure for achieving this goal, we developed a protein microarray of the vaccinia virus proteome by using high-throughput baculovirus expression and purification of individual elements. The array was validated with therapeutic-grade, human hyperimmune sera, and these data were compared to results obtained from individuals vaccinated against smallpox using Dryvax. A high level of reproducibility with a very low background were apparent in repetitive assays that confirmed previously reported antigens and identified new proteins that may be important for neutralizing viral infection. Our results suggest that proteins recognized by antibodies from all vaccinees constituted <10% of the total vaccinia proteome.  相似文献   
8.
Rotary blanking is a method of blanking and punching with rotating tools whereby the cutting tools are fixed to a pair of rollers performing a continuous blanking operation on a strip of sheet metal. The purpose of this paper is to outline the determining conditions under which the rotary blanking process takes place and to discuss advantages, restrictions, applications and optimization of this technology.  相似文献   
9.
10.
Besides their direct impact on the respective correlated color temperature, the extinction coefficient and the quantum effi- ciency of the phosphor also have tremendous impact on the thermal load of the color conversion elements of phosphor converted LEDs under operation. Because of the low thermal conductivity of the silicone matrix in which the phosphor particles are typically embedded, the by far highest temperatures within the LED assembly are reached within the color conversion element. Based on a combined optical and thermal simulation procedure we show that in particular a larger value for the extinction coefficient might have a beneficial impact on the resulting thermal load.  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