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   1709篇
  免费   126篇
  国内免费   71篇
电工技术   116篇
综合类   74篇
化学工业   217篇
金属工艺   85篇
机械仪表   186篇
建筑科学   213篇
矿业工程   142篇
能源动力   100篇
轻工业   251篇
水利工程   79篇
石油天然气   174篇
武器工业   8篇
无线电   26篇
一般工业技术   133篇
冶金工业   65篇
原子能技术   21篇
自动化技术   16篇
  2024年   9篇
  2023年   24篇
  2022年   61篇
  2021年   76篇
  2020年   73篇
  2019年   42篇
  2018年   24篇
  2017年   31篇
  2016年   42篇
  2015年   52篇
  2014年   96篇
  2013年   107篇
  2012年   140篇
  2011年   164篇
  2010年   146篇
  2009年   115篇
  2008年   86篇
  2007年   102篇
  2006年   101篇
  2005年   92篇
  2004年   72篇
  2003年   66篇
  2002年   40篇
  2001年   18篇
  2000年   20篇
  1999年   13篇
  1998年   17篇
  1997年   14篇
  1996年   18篇
  1995年   10篇
  1994年   7篇
  1993年   4篇
  1992年   4篇
  1991年   10篇
  1989年   3篇
  1988年   3篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
排序方式: 共有1906条查询结果,搜索用时 218 毫秒
51.
The paper presents two types of a passive safety containment for a near future BWR. They are named Mark S and Mark X containment. One of their common merits is very low peak pressure at severe accidents without venting the containment atmosphere to the environment. The PCV pressure can be moderated within the design pressure. Another merit is the capability to submerge the PCV and the RPV above the core level. The third merit is robustness against external events such as a large commercial airplane crash. Both the containments have a passive cooling core catcher that has radial cooling channels. The Mark S containment is made of reinforced concrete and applicable to a large power BWR up to 1830 MWe. The Mark X containment has the steel secondary containment and can be cooled by natural circulation of outside air. It can accommodate a medium power BWR up to 1380 MWe. In both cases the plants have active and passive safety systems constituting in-depth hybrid safety (IDHS). The IDHS provides not only hardware diversity between active and passive safety systems but also more importantly diversity of the ultimate heat sinks between the atmosphere and the sea water. Although the plant concept discussed in the paper uses well-established technology, plant performance including economy is innovatively and evolutionally improved. Nothing is new in the hardware but everything is new in the performance.  相似文献   
52.
围岩含水条件下快速测压工艺   总被引:3,自引:0,他引:3  
围岩含水条件下,高压注浆可以实现封堵渗水裂隙,利用胶囊粘液封孔法传统与改进工艺对比测定煤层瓦斯压力,通过在平煤天安十一矿的试验与应用对比,从而在实践中论证了胶囊粘液封孔-补气法快速测压的可行性。  相似文献   
53.
结合工程实际,论述了高压燃气管道不停输封堵施工的方案选择、盘式封堵施工工艺、施工过程的环节控制,提出了改进建议。  相似文献   
54.
徐建月 《中国涂料》2011,26(12):17-19
分析了中国防水行业材料应用市场的发展现状;通过对JS防水涂料采用高压无气喷涂方式在上海3 000 m2实际项目的应用试验,分析了我国防水涂料采用机械化施工在工艺设备上具备的条件,以及给企业带来的利益;指出防水行业应更新理念、创造条件,推动防水涂料机械化施工在我国的发展进程。  相似文献   
55.
针对2号高冲电缆B相接地故障,采用惠斯登电桥和声测法,迅速将故障点查找出来,并进行处理,使2号高冲恢复正常工作。  相似文献   
56.
介绍无损检测对高压充罐的探伤方法,以及对出现缺陷的分析。  相似文献   
57.
本文对高压结晶分离技术的原理、特点、应用及其研究现状进行了综述。  相似文献   
58.
A multi-functional micro-arc plasma spraying system was developed according to aerodynamics and plasma spray theory. The soft switch IGBT (Insulated Gate Bipolar Transistor) invert technique, micro-computer control technique, convergent-divergent nozzle structure and axial powder feeding techniques have been adopted in the design of the micro-arc plasma spraying system. It is not only characterized by a small volume, a light weight, highly accurate control, high deposition efficiency and high reliability, but also has multi-functions in plasma spraying, welding and quenching. The experimental results showed that the system can produce a supersonic flame at a low power, spray Al2O3 particles at an average speed up to 430 m/s, and make nanostructured AT13 coatings with an average bonding strength of 42.7 MPa. Compared to conventional 9M plasma spraying with a higher power, the coatings with almost the same properties as those by conventional plasma spray can be deposited by multi-functional micro-arc plasma spraying with a lower power plasma arc due to an improved power supply design, spray gun structure and powder feeding method. Moreover, this system is suitable for working with thin parts and undertaking on site repairs, and as a result, the application of plasma spraying will be greatly extended.  相似文献   
59.
应用径向基概率神经网络实现高压加热器的故障诊断。介绍了RBPNN网络的结构和学习算法;总结了高加的故障集、征兆集和故障特征数据。在Matlab环境下给出了高加故障诊断的具体实例,表明该方法是一种可行有效的高加故障诊断方法。  相似文献   
60.
Drug nanocrystals are known to increase the solubility of Biopharmaceutics Classification System (BCS) class II and IV drugs. SmartCrystals are the second generation nanocrystals with particle size of less than 100 nm and increased the stability and solubility of drug and drug product. The combinative methods adopted for the preparation of SmartCrystals are reported to shorten the processing time to reduce the particle size of the drug. This study was carried out with the aim to prepare nanosuspensions of aprepitant and ibuprofen using two pretreatment methods, precipitation and ball milling in a combination of high-pressure homogenisation (HPH). Ball milling and precipitation resulted in nanosuspensions having a particle size less than 1 µ, which were subjected to high HPH. HPH further led to a reduction in the particle size. However, the precipitation method failed to reduce the size of ibuprofen particles to 1 µ.  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