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   272篇
  免费   4篇
电工技术   4篇
化学工业   21篇
金属工艺   3篇
机械仪表   8篇
建筑科学   1篇
矿业工程   11篇
能源动力   3篇
水利工程   2篇
石油天然气   5篇
无线电   8篇
一般工业技术   39篇
冶金工业   115篇
原子能技术   8篇
自动化技术   48篇
  2022年   2篇
  2021年   3篇
  2019年   4篇
  2018年   3篇
  2017年   3篇
  2016年   3篇
  2015年   2篇
  2014年   2篇
  2013年   2篇
  2010年   3篇
  2009年   6篇
  2008年   4篇
  2007年   2篇
  2006年   3篇
  2005年   12篇
  2004年   8篇
  2003年   2篇
  2002年   10篇
  2001年   3篇
  2000年   3篇
  1999年   3篇
  1998年   28篇
  1997年   23篇
  1996年   16篇
  1995年   7篇
  1994年   4篇
  1993年   6篇
  1992年   4篇
  1990年   3篇
  1989年   1篇
  1986年   2篇
  1985年   2篇
  1984年   4篇
  1983年   5篇
  1982年   4篇
  1981年   6篇
  1980年   2篇
  1979年   3篇
  1978年   1篇
  1977年   13篇
  1976年   30篇
  1975年   4篇
  1974年   3篇
  1973年   3篇
  1972年   3篇
  1971年   2篇
  1970年   8篇
  1968年   2篇
  1963年   1篇
  1958年   1篇
排序方式: 共有276条查询结果,搜索用时 15 毫秒
101.
102.
Decrease of beta-lipoprotein resistance to copper-dependent oxidation is an important diagnostic criterion of risk of atherosclerosis. We developed a simple method for assessing resistance of heparin-precipitated beta-lipoproteins to oxidation induced by 50 microM copper ions. A strong positive correlation between the oxidation of precipitated and ultracentrifuged beta-lipoproteins in the presence of 50 and 10 microM copper ions, respectively, was revealed. In coronary patients oxidation resistance of precipitated beta-lipoproteins was decreased in comparison with that in healthy donors. The method is simple, informative, and easily available for clinical biochemical laboratories.  相似文献   
103.
The paper surveys state-of-the-art supercomputer and mini supercomputer architectures. Computer development trends and the associated problems are discussed.Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 133–141, March–April, 1992.  相似文献   
104.
Medical records of 876 servicemen of a young age who have suffered various forms of clinical diphtheria were analysed. (Lethal cases were marked in 52 cases--5.9%). A true clinical symptom complex for the diagnosis of diphtheria at pre-hospital period is as following: fever, intoxication and febrinous tonsillitis. The main cause of unfavourable outcome of the disease depends on the affection of cardiovascular, central and peripheral nerve systems by diphtheritic exotoxin. The most frequent limitations during medical care were the following: error diagnosis of angina (41%), late hospitalization and late specific treatment, insufficient doses of antidiphtheric serum, inopportune diagnosis of severe aggravations (infectious toxic shock, pneumonia).  相似文献   
105.
106.
The work was conducted on Wistar rats who had received orally the xenobiotic hexachlorocyclohexane (HClCH) in different doses. The sizes of the alveolar macrophages and type II pneumocytes as well as the parameters of macrophage phagocytosis were studies. Administration of HClCH in subtoxic doses not exceeding the pesticide residues in the food in the first two months stimulated synthesis of the surfactant and its phagocytosis by the alveolar macrophages; further administration of the primer led to exhaustion of the cell function. A toxic HClCH dose induced synchronous stimulation of the functional interaction of the alveolar macrophages and type II pneumocytes by the end of the second month. Synthesis of the surfactant and its phagocytosis were stabilized in the period of the after-effect of the drug.  相似文献   
107.
193 patients with coronary heart disease were examined to study potentialities of noninvasive diagnosis of coronary artery lesions, their location and severity using transesophageal echocardiography in combination with transesophageal stimulation. This method of stress-test proved highly sensitive (89%) and specific (84%) in noninvasive diagnosis of both location of coronary atherosclerosis and its severity (stenosis, subtotal stenosis, occlusion) and extension.  相似文献   
108.
Sera of healthy and sick persons were tested for the presence of secretory IgA (SIgA) and free secretory component (SC) SIgA was present in the blood of healthy persons in low concentrations (1.07 mg/100 mg), and free SC was absent. Infectious and somatic diseases, in which damage of the epithelial covering of the gastrointestinal and respriatory tracts was possible, were accompanied by increased blood SIgA content. There was also noted a distinct relationship between the blood SIgA concentration and the severity of infectious diseases and pneumonia supervention. In these cases the SIgA level proved to rise.  相似文献   
109.
1.  In choosing a type of steel for conditions involving repeated impacts, it is essential to allow for the reliable working reserve of the structure or the constituent elements subjected to this loading.
2.  The external form of the fractures enables us to determine the character of the breaking load. For static and single impact loading there are three zones of plastic yield situated on the three sides of the cross section (a part from the notch side). Under conditions of repeated impact loading, a fatigue crack necessarily arises, together with only two zones of plastic yield (on the vertical sides of the cross section). The area of the zones of plastic yield is much smaller than in the first two cases of loading and depends on the value of Aim.
3.  By considering the form of the fracture surface we may judge the number of loading cycles. For a small number of cycles and a high impact energy, the final fracture zone occuples a large area, the cross section has an undulating structure, and the zones of plastic yield are considerable. For low impact energies the area occupied by the fatigue crack is greater, the final fracture less undulating, the zones of plastic yield smallish, the front of the fatigue crack directed with its convexity upward, and the relaxation lines more sparsely evident. The fractures confirm that for large impact energies the fracture bears a quasistatic character and for small energies, a fatigue character.
4.  After 5·104 cycles and static completion of the fracture by bending all the samples had macro-or microfatigue cracks, so that the breaking load and the work required to complete the fracture by bending diminished.
  相似文献   
110.
Russian Engineering Research - The use of classical and parametric spectral analysis in monitoring industrial equipment—in particular, metal-cutting machines—is considered. Particular...  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