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   578篇
  免费   1篇
电工技术   1篇
化学工业   67篇
金属工艺   3篇
机械仪表   13篇
建筑科学   2篇
轻工业   13篇
石油天然气   3篇
无线电   10篇
一般工业技术   17篇
冶金工业   437篇
原子能技术   5篇
自动化技术   8篇
  2022年   5篇
  2018年   10篇
  2017年   3篇
  2016年   3篇
  2015年   2篇
  2013年   9篇
  2012年   8篇
  2011年   14篇
  2010年   5篇
  2009年   3篇
  2008年   2篇
  2007年   4篇
  2005年   4篇
  2004年   3篇
  2002年   1篇
  2001年   1篇
  2000年   2篇
  1999年   9篇
  1998年   123篇
  1997年   64篇
  1996年   53篇
  1995年   33篇
  1994年   22篇
  1993年   29篇
  1992年   4篇
  1991年   6篇
  1990年   6篇
  1989年   8篇
  1988年   3篇
  1987年   10篇
  1986年   9篇
  1985年   6篇
  1984年   2篇
  1982年   7篇
  1981年   7篇
  1980年   6篇
  1979年   1篇
  1978年   5篇
  1977年   23篇
  1976年   31篇
  1975年   3篇
  1974年   3篇
  1973年   5篇
  1972年   1篇
  1971年   2篇
  1970年   2篇
  1969年   5篇
  1967年   3篇
  1966年   3篇
  1965年   1篇
排序方式: 共有579条查询结果,搜索用时 31 毫秒
11.
Seismic tests of full-scale mockups of fuel assemblies from the VVER-1000 reactor permit the determination of the transfer characteristics between the stimulus (acceleration of the supports) and the response of the fuel assemblies. No resonant responses of the fuel assemblies to seismic loads are observed.  相似文献   
12.
13.
Basic parameters of a queueing network are its routing matrix, arrival flow rate, and service rates at network nodes. To estimate these parameters, one has to solve a system of balance equations. In turn, a product-form limiting distribution of the number of customers at the network nodes is defined through loading factors. Therefore, in the paper we propose to estimate loading factors through estimates of the limiting distribution based on observations of the number of customers at the nodes. This makes it possible to avoid solving a system of balance equations. This algorithm is realized for Jackson networks: classical, in a random environment, with blocked transitions.  相似文献   
14.
The article presents the experience of the work on the sanitary education of the workers of the milk industry plants in Moscow and Moscow Province. The Institute's specialists had worked out basing on the studied experience the program of the full-time and external differential sanitary education of the workers of the milk industry which was approved by the Department of the State Sanitary Control of the Ministry of Health of Russia the April 22, 1998. "An exercise book for the sanitary education of the workers of the milk industry plants" was also prepared and published in 1999.  相似文献   
15.
16.
BACKGROUND: The precise mechanisms involved in islet xenograft rejection remain unknown. The purpose of the present study was to determine cellular mechanisms responsible for islet xenograft rejection in the liver to facilitate finding a procedure for prevention of immune rejection. METHODS: Hepatic mononuclear cells (MNC) as well as splenocytes, peripheral blood MNC, and thymocytes from streptozotocin-induced diabetic mice (BALB/c) rejecting the intrahepatic rat (Lewis) islet xenografts were isolated and examined by two-color FACS analysis. RESULTS: The characteristic finding of the hepatic MNC from the mice rejecting islet xenografts compared with mice receiving isografts was a significant increase in the yield as well as in the percentage of the cells expressing CD3+ interleukin-2 receptor (IL-2R) alpha- beta+, CD3+ CD8alpha+ beta+, and T cell receptor (TCR) alphabeta+ lymphocyte function-associated antigen-1+. The expression of CD3 and TCR alphabeta of these T cells was found to be of intermediate intensity (TCR(int) cells). The expansion of these TCR(int) cells occurred predominantly in the liver. There was no significant difference in the cells expressing CD3+ IL-2R alpha+, CD3+ CD4+, CD3+ TCRgammadelta+, CD3- IL-2Rbeta+ (natural killer cells), and B220+ (B cells). In vivo administration of anti-IL-2Rbeta monoclonal antibody directed to the expanded cells produced a prevention of rejection. CONCLUSIONS: These findings suggest that islet xenograft rejection in the liver from rat to mouse is an event for which the TCR(int) cells are responsible.  相似文献   
17.
AIM: This study of trimetasidine effects on plasmic hemostasis and blood biochemistry in patients with chronic heart failure (CCF) of NYHA functional class II-III. MATERIALS AND METHODS: This study enrolled 30 patients (24 males and 6 females) aged 40-72 years with class II-III CCF, postinfarction cardiosclerosis and ejection fraction under 40%. Previously the patients received perindopril (the inhibitor of angiotensin converting enzyme) in daily dose 2-4 mg, on-demand digoxin and diuretics. Trimetasidine was given in a daily dose 60 mg for 6 months. Before and after the treatment the patients' blood was examined for: levels of factors VII and X of antithrombin III coagulation, soluble fibrinomonomeric complexes (SFMC), fibrinogen, glucose, uric acid, creatinines, total cholesterol, high density lipoprotein, triglycerides, AST, ALT, LDH, acid phosphotase, gamma-GT, sodium, potassium, activated partial thrombin time. RESULTS: Initially, the patients had a 23.9% increase in the levels of factors VII and X, a 14.3% decrease of antithrombin III, 29.8 and 227.6% rise in concentrations of fibrinogen and SFMC, respectively, compared to controls. Aftertreatment values of fibrinogen, factors VII and X, SFMC fell by 21.1, 17 and 35.5%, respectively. The thrombin time arose by 17.9% (p > 0.05). Insignificant inhibition was registered in the activity of acid phosphotase and gamma-GT. Glucose, AST, ALT, LDH levels remained unchanged. Plasma creatinine tended to lowering. Total cholesterol insignificantly increased at high levels of HDL cholesterol (p > 0.05) and reduced levels of triglycerides (p > 0.05). CONCLUSIONS: Trimetasidine therapy, given after conventional treatment with diuretics, digoxin, inhibitor of angiotensin-converting enzyme, aspirin has a beneficial effect in patients with circulatory deficiency through improving hemostatic and biochemical parameters.  相似文献   
18.
19.
20.
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