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   347篇
  免费   1篇
电工技术   8篇
化学工业   26篇
金属工艺   11篇
机械仪表   15篇
建筑科学   5篇
矿业工程   2篇
能源动力   5篇
轻工业   3篇
水利工程   24篇
石油天然气   41篇
无线电   4篇
一般工业技术   46篇
冶金工业   127篇
原子能技术   21篇
自动化技术   10篇
  2021年   10篇
  2020年   3篇
  2018年   13篇
  2017年   11篇
  2016年   9篇
  2015年   5篇
  2014年   13篇
  2013年   9篇
  2012年   8篇
  2011年   9篇
  2010年   5篇
  2009年   9篇
  2008年   7篇
  2007年   14篇
  2005年   2篇
  2004年   7篇
  2003年   2篇
  2002年   8篇
  2001年   2篇
  2000年   3篇
  1998年   27篇
  1997年   7篇
  1996年   11篇
  1995年   4篇
  1994年   4篇
  1993年   7篇
  1992年   9篇
  1991年   5篇
  1990年   5篇
  1989年   2篇
  1988年   4篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1983年   3篇
  1981年   5篇
  1980年   7篇
  1979年   4篇
  1978年   6篇
  1977年   12篇
  1976年   24篇
  1975年   5篇
  1974年   5篇
  1973年   4篇
  1972年   5篇
  1971年   6篇
  1970年   3篇
  1969年   2篇
  1968年   3篇
  1965年   2篇
排序方式: 共有348条查询结果,搜索用时 15 毫秒
1.
2.
Studied in the course of one-stage epidemiologic survey of 1191 individuals were the threshold of gustatory sensitivity to table salt and nycterine natriuresis, relation of these indices to dietary habits, some risk factors for cardiovascular disorders and clinical parameters. Differing relations were established between gustatory sensitivity to table salt and natriuresis and age and gender of the examinees, the level of blood pressure, aggravated heredity in respect of arterial hypertension, smoking and alcohol abuse, this enabling one to embark upon a differential approach to dietetic correction of salt consumption.  相似文献   
3.
Disturbance of the grounding of the shaft of a turboset or its absence for technical reasons can result in failure, misoperation, limitation of the operating zone, errors or limitation of the sensitivity of devices for control and protection of exciting circuits from single-point leakage, and electroerosion of elements of the turboset structure. Measures for increasing the reliability of the grounding of the shaft are discussed. __________ Translated from élektricheskie Stantsii, No. 3, March 2006, pp. 61–66.  相似文献   
4.
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 4, pp. 34–39, April, 1992.  相似文献   
5.
6.
Cell heterogeneity of cytochemical characteristics of chromatin in the norm and after provocative factors in vitro (a heating at 45 degrees C, X-irradiation and joint actions of heating and X-ray irradiation) was investigated in the peripheral blood mononuclear cells of sheep and mouse, the lymphoid cell populations of the murine bone marrow, spleen and thymus. As a criterion of cytochemical heterogeneity were used the distinctions in the rate of staining of cell nuclei with DNA-specific dyes, that was registered by means of measurement of coefficient variation of the DNA-histogram basis peak, with a flow cytometry. Heterogeneity of cytochemical characteristics are dealt with showed a variability of spatial organization of interphase nuclei of single cells. The provocative factors bring about a decrease in the level of the cytochemical characteristics heterogeneity in the sheep mononuclear cells. In the murine cell populations studied no such equalizing of the marker of variability was revealed.  相似文献   
7.
Internal carotid aneurysms in the ophthalmic area presents a challenge in cerebrovascular neurosurgery. The study was undertaken to provide evidence for the application of intravascular aspiration during direct surgical interventions and to outline their variants used at the N. N. Burdenko Institute of Neurosurgery. The study included 4 (3 females and 1 male) patients with large and giant internal carotid aneurysms of parasphenoidal site who were treated at the Institute. Clipping of the aneurysmal neck was made by employing intravascular blood aspiration from the aneurysm. The technique proved to be effective in proximal monitoring the carotid artery at surgery. It substantially reduced aneurysmal blood flow and wall tension, thus favouring aneurysmal dissection to make clipping.  相似文献   
8.
The vacuum production of diamond drill bits is considered. The effect from the concentration of an adhesive-active element (chromium) on the diamond-tool contact strength is analyzed. It is examined how the binder affects the dependence of diamond-retaining force on the chromium content.  相似文献   
9.
The results of development work on an innovative low-capacity nuclear power plant (LCNPP) Uniterm together with substantiation of the need for a technical design of a reactor system and the basic design of the power plant are presented. The results of the work are used to determine the power range of the power generating unit where the main consumer qualities are guaranteed to be attained. Economic assessments of the development and operation of a two-block LCNPP under conditions in Russia are presented. __________ Translated from Atomnaya énergiya,Vol. 103, No. 1, pp. 44–48, July, 2007.  相似文献   
10.
Results concerning the terminal guidance algorithm at the reentry of the descent module into the Earth atmosphere are presented. This algorithm simultaneously eliminates predicted deviations in the downrange and crossrange directions. The restriction on the tolerable load factor n ?? 3 is taken into account. Three reentry angles are analyzed: the medium angle ?1.5°, the steep angle ?1.9°, and the flat angle ?1.2°. The motion of the descent module is considered in the disturbed Earth atmosphere represented by the TsNIIMash model. This model includes variations of the atmosphere density and the wind field. It is demonstrated that, depending on the reentry angle, the proposed algorithm guarantees the downrange maneuver zone in the range 1240?C1890 km and the crossrange maneuver zone of 210?C220 km on one side. The maximum guidance error at the altitude of 1 km does not exceed 0.8 km, and the average error is 0.1 km. The algorithm uses up to three bank angle reversals and uses the numerical prediction of the remaining part of the trajectory when choosing the guidance parameters. The concept of the automatic adjustment of the bank angle reference function depending on the entry angle and the prescribed distance to the target point in the maneuver zone is formulated.  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