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   3258篇
  免费   51篇
  国内免费   141篇
电工技术   92篇
综合类   32篇
化学工业   284篇
金属工艺   91篇
机械仪表   89篇
建筑科学   83篇
矿业工程   17篇
能源动力   360篇
轻工业   95篇
水利工程   11篇
石油天然气   43篇
武器工业   4篇
无线电   29篇
一般工业技术   267篇
冶金工业   29篇
原子能技术   1695篇
自动化技术   229篇
  2024年   2篇
  2023年   31篇
  2022年   70篇
  2021年   73篇
  2020年   99篇
  2019年   45篇
  2018年   50篇
  2017年   93篇
  2016年   125篇
  2015年   50篇
  2014年   122篇
  2013年   186篇
  2012年   131篇
  2011年   298篇
  2010年   145篇
  2009年   143篇
  2008年   117篇
  2007年   133篇
  2006年   128篇
  2005年   137篇
  2004年   97篇
  2003年   110篇
  2002年   114篇
  2001年   68篇
  2000年   79篇
  1999年   100篇
  1998年   80篇
  1997年   69篇
  1996年   76篇
  1995年   70篇
  1994年   48篇
  1993年   67篇
  1992年   46篇
  1991年   32篇
  1990年   46篇
  1989年   45篇
  1988年   15篇
  1987年   12篇
  1986年   10篇
  1985年   15篇
  1984年   26篇
  1983年   10篇
  1982年   11篇
  1981年   4篇
  1980年   2篇
  1977年   2篇
  1976年   5篇
  1975年   3篇
  1974年   3篇
  1973年   4篇
排序方式: 共有3450条查询结果,搜索用时 31 毫秒
31.
磁偏转电子枪研制核靶   总被引:3,自引:3,他引:0  
文章叙述了磁偏转电子枪的原理和结构以及用EQD-3型电子枪研制各种核靶的工艺过程。  相似文献   
32.
核医学成像技术中计算机的应用   总被引:2,自引:2,他引:0  
由于计算机和核医学的结合,各种成像方法的计算机化医学图像层析技术正在迅速发展,并开始广泛应用。本文介绍各类成像技术中计算机的应用,特别评述其最近进展,并提出了今后的展望。  相似文献   
33.
Different NMR techniques were combined to obtain the structure and velocity information for a systematic investigation of fixed beds with low aspect ratio (tube diameter to particle diamter, dt/dp) in the range 1.4 to 32. The structure of the void space was determined for a variety of packed beds of glass beads or regular and irregular porous pellets by magnetic resonance imaging (MRI). Based on the images the radial distribution of the voids within the bed was obtained. Ordering effects were found even for non‐spherical and polydisperse particles, and a maximum of the fluid density near the tube wall was confirmed for all pellet geometries and sizes. By combining MRI with velocity encoding, velocity profiles and distributions of flow velocity components of a single fluid phase through packed beds have been acquired. The radial velocity distribution follows an oscillatory pattern which largely reflects the ordering of the particles, which can be accessed from the density distribution of the interparticle fluid. Maximum velocities of up to four times the average value were found to occur near the tube wall. This wall effect was observed for all but the smallest particles, where the aspect ratio was dt/dp = 32. Moreover, a visualisation of flow pattern in the presence of packed particles was achieved by using a tagging technique, and the stationary flow field could be identified for an experimental time of several hours.  相似文献   
34.
介绍了863智能机器人型号之一-以核工业为应用背景的“勇士号”遥控移动式机器人的作业内容及其主要功能指标,分析了该型号的总体设计思想,同时概括总结了其操作性能,移动性能及计算机系统等方面的技术特点。  相似文献   
35.
RELAP5程序与三维时空中子动力学模型的耦合以及改进研究   总被引:2,自引:0,他引:2  
桂学文  骆邦其  蔡琦 《核动力工程》2007,28(1):49-52,86
引入堆芯物理计算的两群三维时空中子动力学模型,对RELAP5程序的点堆中子动力学模型进行了改进,同时设计了可视化界面,可方便地实现人.机交互操作.计算结果与实际应用表明,改进后的RELAP5程序计算功能和精度得到提高,使用更加方便,在核动力装置的仿真方面有很好的应用前景.  相似文献   
36.
An overview of current nuclear power generation and fuel cycle strategies in Europe is presented, with an emphasis on options for the management of separated plutonium in the medium to long term. Countries which have opted for reprocessing of spent fuel have had to contend with increasing inventories of separated plutonium. Of the various potential options for utilisation or disposition of these stockpiles, only light water reactor (LWR) mixed-oxide (MOX) fuel programmes are sufficiently technologically mature to be fully operational in several European countries at present. Such reprocessing-recycling programmes allow for a stabilisation of the overall separated plutonium stocks, but not for a significant reduction in the stockpile. Moreover, the quality of recycled plutonium decreases at each potential step of re-irradiation. Therefore, optimised or new ways of managing the plutonium stocks in the medium to long term are required. In the present overview we consider the most promising options for reactor utilisation of plutonium in both near-term future reactor and Generation IV systems.  相似文献   
37.
The Technical University of Catalonia (UPC) has been jointly working with the Asociación Nuclear Ascó-Vandellòs (ANAV) for a number of years in order to establish, qualify and use best estimate (BE) models for the reactors under the control of ANAV. ANAV is the consortium that is responsible for operation of the Ascó and Vandellòs-II reactors. The reactors are Westinghouse-design three-loop PWRs with an approximate electrical power of 1000 MW. The existing integral plant models for each plant are currently used for many different purposes among which are support of plant operation and control. Quite a number of studies have been done in order to improve both safety and plant competitiveness. Most of these dynamic analyses were carried out in relation to transients starting at nominal full power or at least, very close to full power. This paper develops a specific use of the Vandellòs-II plant model for operation and control support at low power involving new ranges of system actuation parameters. It also examines scenarios that are somewhat different from those typically analysed. The study starts showing the results of an assessment case, which is a start-up test and provides some additional qualification, and subsequently attempts to establish calculations to support both an improvement in feed water controls and to set up operating recommendations for low-load manual operation of feed water turbo-pump. Both results hopefully, will produce an outcome, which leads to an improvement in safety and reduces reactor trip probability.  相似文献   
38.
周玲 《核动力工程》2002,23(2):97-100
先进的报警系统是核电厂先进的控制室中重要的系统之一,阐述了核电厂先进的报警系统的重要性、功能和特点,并且比较详细地论述了报警信号的处理方法和显示方式。  相似文献   
39.
A mathematical model for analysis of process parameters of equipment in the second circuit of nuclear power plants is presented, and the structure of the program and principles used for analysis of the equipment are described. A mathematical model for analysis of the deaerator and steam generator is described in detail. A computational analysis of several transitional modes, which is made possible on the basis of the mathematical model in question, is also presented in this paper, and a comparison is made with test data. __________ Translated from élektricheskie Stantsii, No. 3, March 2007, pp. 16–22.  相似文献   
40.
Because of the huge volume of capital required to construct a modern electric power generating station, investment decisions have to be made with as complete an understanding of the consequences of the decision as possible. This understanding must be provided by the evaluation of future situations. A key consideration in an evaluation is the financial component. This paper attempts to use an econometric method to forecast the construction costs escalation of a standard Canadian nuclear generating station (NGS). A brief review of the history of Canadian nuclear electric power is provided. The major components of the construction costs of a Canadian NGS are studied and summarized. A database is built and indexes are prepared. Based on these indexes, an econometric forecasting model is constructed using an apparently new econometric methodology of forecasting modelling. Forecasts for a period of 40 years are generated and applications (such as alternative scenario forecasts and range forecasts) to uncertainty assessment and/or decision-making are demonstrated. The indexes, the model, and the forecasts and their applications, to the best of the author's knowledge, are the first for Canadian NGS constructions.  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