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   2451篇
  免费   70篇
  国内免费   5篇
电工技术   24篇
综合类   3篇
化学工业   691篇
金属工艺   34篇
机械仪表   33篇
建筑科学   175篇
矿业工程   62篇
能源动力   43篇
轻工业   235篇
水利工程   56篇
石油天然气   1篇
无线电   165篇
一般工业技术   319篇
冶金工业   253篇
原子能技术   18篇
自动化技术   414篇
  2021年   28篇
  2018年   23篇
  2017年   24篇
  2016年   61篇
  2015年   53篇
  2014年   82篇
  2013年   91篇
  2012年   135篇
  2011年   131篇
  2010年   83篇
  2009年   87篇
  2008年   98篇
  2007年   99篇
  2006年   135篇
  2005年   62篇
  2004年   50篇
  2003年   51篇
  2002年   57篇
  2001年   31篇
  2000年   41篇
  1999年   44篇
  1998年   59篇
  1997年   43篇
  1996年   38篇
  1995年   30篇
  1994年   43篇
  1993年   40篇
  1992年   32篇
  1991年   35篇
  1990年   36篇
  1989年   29篇
  1988年   29篇
  1987年   24篇
  1986年   25篇
  1985年   29篇
  1984年   36篇
  1983年   23篇
  1982年   34篇
  1981年   36篇
  1980年   25篇
  1979年   34篇
  1978年   25篇
  1977年   27篇
  1976年   38篇
  1975年   30篇
  1974年   32篇
  1973年   22篇
  1972年   21篇
  1971年   21篇
  1970年   27篇
排序方式: 共有2526条查询结果,搜索用时 31 毫秒
1.
Corynebacterium silvaticum is a newly identified animal pathogen of forest animals such as roe deer and wild boars. The species is closely related to the emerging human pathogen Corynebacterium ulcerans and the widely distributed animal pathogen Corynebacterium pseudotuberculosis. In this study, Corynebacterium silvaticum strain W25 was characterized with respect to its interaction with human cell lines. Microscopy, measurement of transepithelial electric resistance and cytotoxicity assays revealed detrimental effects of C. silvaticum to different human epithelial cell lines and to an invertebrate animal model, Galleria mellonella larvae, comparable to diphtheria toxin-secreting C. ulcerans. Furthermore, the results obtained may indicate a considerable zoonotic potential of this newly identified species.  相似文献   
2.
3.
4.
This paper analyses the characteristics of software houses as service providers. The tasks of internal IT-services are determined from these characteristics and a reporting system for the IT-controlling is outlined. The concept results from the analysis of one of the 25 largest German software houses. The paper concludes with a case study of the fiscal year 2000 IT-controlling report of the above-mentioned firm.  相似文献   
5.
6.
Rationalizing drawings for chemical apparatus . For small and medium-sized manufacturers of apparatus, producing drawings may constitute a disproportionate waste of time and personnel, particularly when no new designs are involved but only modification or improvement of drawings supplied by the customer. One possibility for rationalizing drawing is to simplify the old-fashioned approach by using symbols for frequently drawn or standard items, or by listing alphanumerically. This presumes a kind of systematization permitting determination of those symbols and their reasonable use, as well facilitating rationalization by means of data processing. There are different approaches to computer-aided drawing (from computer controlled drawing-board to interactive screens); here a CAD programme is presented which was especially developed for graphic presentation of chemical apparatus, and which can be used without learning a programming language.  相似文献   
7.
8.
Sulfonylureas have, in the past, been reported to have adverse cardiovascular effects. Glimepiride is a new sulfonylurea. In spite of stimulating less insulin secretion, it has, depending on the species, equal or higher blood glucose decreasing activity and according to preliminary studies less cardiovascular activity than glibenclamide. Further studies were performed to confirm the lower cardiovascular activity of glimepiride. The IC50 for inhibition of rilmakalim-activated KATP channel currents in isolated ventricular myocytes was 31.6 nM for glimepiride and 6.8 nM for glibenclamide. In endotoxin shock-rats at a dose of 1 x 2 mg/kg i.v., glibenclamide induced a significantly higher blood pressure increase than glimepiride. At two i.v. doses of 20 mg/kg 4 min apart, in normal rats, glibenclamide produced signs of ischemia in the ECG in nearly all animals, glimepiride almost none, in diabetic rats, glibenclamide produced in all animals a lethal cardiogenic shock preceeded by serious ECG changes, glimepiride only in one fifth of the animals. In open-chest dogs, on intracoronary infusion of equieffective blood glucose-lowering doses, glibenclamide, gliclazide and glimepiride all reduced coronary blood flow, increased coronary resistance, depressed the mechanical activity of the heart, enhanced myocardial O2-extraction, reduced the serum potassium level and induced a moderate endocardial ST-segment elevation, but glimepiride to a significantly less extent than glibenclamide and gliclazide. The presented data confirm that glimepiride at equivalent blood glucose decreasing doses has less cardiovascular activity than conventional sulfonylureas.  相似文献   
9.
10.
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