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   339篇
  免费   35篇
电工技术   2篇
化学工业   201篇
金属工艺   2篇
机械仪表   3篇
建筑科学   8篇
能源动力   15篇
轻工业   74篇
水利工程   1篇
石油天然气   1篇
无线电   8篇
一般工业技术   35篇
冶金工业   8篇
原子能技术   1篇
自动化技术   15篇
  2024年   1篇
  2023年   8篇
  2022年   70篇
  2021年   73篇
  2020年   14篇
  2019年   24篇
  2018年   14篇
  2017年   24篇
  2016年   16篇
  2015年   12篇
  2014年   15篇
  2013年   23篇
  2012年   14篇
  2011年   19篇
  2010年   8篇
  2009年   6篇
  2008年   5篇
  2007年   4篇
  2006年   2篇
  2005年   3篇
  2004年   2篇
  2003年   2篇
  2002年   4篇
  1998年   2篇
  1997年   1篇
  1995年   1篇
  1991年   1篇
  1990年   1篇
  1987年   1篇
  1986年   1篇
  1984年   2篇
  1970年   1篇
排序方式: 共有374条查询结果,搜索用时 203 毫秒
91.
The present work is concerned with magnetic convection of a paramagnetic fluid in a cubic enclosure heated and cooled from the sidewalls. The influence of a 10-T transverse magnetic field on the convection mode of a paramagnetic fluid and the heat transfer rate was investigated numerically and experimentally, and compared with gravitational natural convection. The present study clearly shows that natural convection can be enhanced and the direction of the convective flow can be changed when using a strong magnetic field in terrestrial conditions.  相似文献   
92.
The paper presents problems related to the assessment of historical objects, especially brick arch structures, in view of potential improvement of their strength using various technologies. We have presented the methodology and computer simulations used for assessment of present strain and load bearing capacity of brick arches along with a variety of reinforcement techniques. We also present arch deformation FEM analysis along with results of assessment of actual objects.  相似文献   
93.
In this study, scanning electron microscopy (SEM) has been applied for instantaneous assessment of processes occurring at the site of regenerating nerve. The technique proved to be especially useful when an artificial implant should have been observed but have not yet been extensively investigated before for assessment of nerve tissue. For in vivo studies, evaluation of implant's morphology and its neuroregenerative properties is of great importance when new prototype is developed. However, the usually applied histological techniques require separate and differently prepared samples, and therefore, the results are never a 100% comparable. In our research, we found SEM as a technique providing detailed data both on an implant behavior and the nerve regeneration process inside the implant. Observations were carried out during 12‐week period on rat sciatic nerve injury model reconstructed with nerve autografts and different tube nerve grafts. Samples were analyzed with haematoxylin‐eosin (HE), immunocytochemical staining for neurofillament and S‐100 protein, SEM, TEM, and the results were compared. SEM studies enabled to obtain characteristic pictures of the regeneration process similarly to TEM and histological studies. Schwann cell transformation and communication as well as axonal outgrowth were identified, newly created and matured axons could be recognized. Concurrent analysis of biomaterial changes in the implant (degradation, collapsing of the tube wall, migration of alginate gel) was possible. This study provides the groundwork for further use of the described technique in the nerve regeneration studies. SCANNING 35: 232‐245, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
94.
Although sex differences in the brain are prevalent, the knowledge about mechanisms underlying sex-related effects on normal and pathological brain functioning is rather poor. It is known that female and male brains differ in size and connectivity. Moreover, those differences are related to neuronal morphology, synaptic plasticity, and molecular signaling pathways. Among different processes assuring proper synapse functions are posttranslational modifications, and among them, S-palmitoylation (S-PALM) emerges as a crucial mechanism regulating synaptic integrity. Protein S-PALM is governed by a family of palmitoyl acyltransferases, also known as DHHC proteins. Here we focused on the sex-related functional importance of DHHC7 acyltransferase because of its S-PALM action over different synaptic proteins as well as sex steroid receptors. Using the mass spectrometry-based PANIMoni method, we identified sex-dependent differences in the S-PALM of synaptic proteins potentially involved in the regulation of membrane excitability and synaptic transmission as well as in the signaling of proteins involved in the structural plasticity of dendritic spines. To determine a mechanistic source for obtained sex-dependent changes in protein S-PALM, we analyzed synaptoneurosomes isolated from DHHC7-/- (DHHC7KO) female and male mice. Our data showed sex-dependent action of DHHC7 acyltransferase. Furthermore, we revealed that different S-PALM proteins control the same biological processes in male and female synapses.  相似文献   
95.
Fast and efficient procedures are increasingly important in process development since the time frame between development and market entry is reduced. The evaluation of alternatives is time consuming, but especially important to assure the choice of the optimal process. A simple and fast method to speed up process development while considering numerous alternatives has been developed using option trees. The option trees allow for easy and comprehensible evaluation of alternatives. Here the method of cascaded option trees is illustrated for the development of a biocompatible separation process.  相似文献   
96.
97.
98.
99.
100.
Clean Technologies and Environmental Policy - Nowadays, a large part of daily activities is associated with the use of fossil fuels. Therefore, the excessive exploitation and related pollution have...  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