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   812篇
  免费   28篇
  国内免费   8篇
电工技术   79篇
综合类   3篇
化学工业   257篇
金属工艺   18篇
机械仪表   17篇
建筑科学   14篇
矿业工程   1篇
能源动力   37篇
轻工业   71篇
石油天然气   6篇
无线电   56篇
一般工业技术   109篇
冶金工业   36篇
原子能技术   45篇
自动化技术   99篇
  2023年   2篇
  2022年   10篇
  2021年   25篇
  2020年   8篇
  2019年   10篇
  2018年   14篇
  2017年   13篇
  2016年   16篇
  2015年   11篇
  2014年   20篇
  2013年   47篇
  2012年   38篇
  2011年   60篇
  2010年   37篇
  2009年   33篇
  2008年   42篇
  2007年   35篇
  2006年   52篇
  2005年   43篇
  2004年   20篇
  2003年   22篇
  2002年   28篇
  2001年   17篇
  2000年   25篇
  1999年   19篇
  1998年   16篇
  1997年   15篇
  1996年   17篇
  1995年   10篇
  1994年   16篇
  1993年   5篇
  1992年   9篇
  1991年   11篇
  1990年   10篇
  1989年   8篇
  1988年   8篇
  1987年   7篇
  1986年   6篇
  1985年   4篇
  1984年   9篇
  1983年   8篇
  1982年   9篇
  1980年   10篇
  1979年   5篇
  1978年   7篇
  1977年   4篇
  1975年   2篇
  1970年   1篇
  1966年   2篇
  1965年   1篇
排序方式: 共有848条查询结果,搜索用时 15 毫秒
101.
“Tracing the power flow of electricity” is a concept that has become the focus of attention recently, as the deregulation or the liberalization of the electric power market proceeds. Although a number of methods, such as “tracing method by power flow contribution,” have already been published, reactive power contribution has been little studied to date. However, applying “tracing the power flow of electricity” to ancillary service, for example compensation of reactive power, is very important. In this paper, we focus on line flows and static capacitors in particular, and study how to deal with the problem. We perform a computer simulation using a simple system and show the tracing results. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 156(1): 33–43, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/ eej.20118  相似文献   
102.
The screening of a strain which could perform lignin removal was carried out. Based on taxonomic study the isolated strain (LM‐2) was identified as Penicillium sp. LM‐2 could decolorize 0.6 g dm?3 lignin within 4 days in a shaking culture at 25 °C. The efficiency of decolorization of the lignin was over 80% in the pH range of 4.0–6.0, but was low above pH 6.2. The rise of temperature had a slight adverse effect on the lignin decolorization in the range of 25–35 °C. Lignolytic enzymes such as lignin peroxidase, manganese peroxidase and laccase were not detected in the culture broth or within the fungal cells. The lignin was removed from the high molecular weight fraction mainly by adsorption and accumulation inside the cells. © 2001 Society of Chemical Industry  相似文献   
103.
Small-angle X-ray scattering of long-period structures forming bundles   总被引:1,自引:0,他引:1  
Small-angle X-ray scattering (SAXS) patterns have been calculated based on a structure model, which consisted of the bundles of long-period structures. The proposed model has produced various scattering patterns of polymers, such as the equatorial, layer line, four-spot, droplet-shaped and triangular scattering. The 0.5th order scattering has arisen when the disorder in or between the long-period structures was large even though the structure did not have the periodicity directly related to the scattering maximum. A slight decrease in the disorder due to slip between the long-period structures has accounted for the sudden change of the SAXS pattern of a poly(ethylene terephthalate) fiber from the four-spot to the layer line scattering which was caused by a slight tensile deformation.  相似文献   
104.
105.
Summary Insoluble polymer-supported amino acids have been synthesized by simple one-pot synthesis. Amino acids were solubilized in organic solvent by trimethylsilylation. Solubilized amino acids (L-Tyr, L-Ser, D-HPG, L-Cys) having functional groups such as OH or SH were easily attached to crosslinked polystyrene beads through benzyl ether or thioether linkage. Other amino acids without extra functional groups could be attached to the polymer through benzyl amine linkage.  相似文献   
106.
107.
An algorithm for measuring an index of leakage in fluorescein fundus angiography is presented. The number of pixels whose gray level exceeds an automatically determined slice level is calculated. An automatic blood vessel elimination technique is introduced. Further, a method of measuring the short term change of leakage from a time series of the fluorescein fundus angiographs is described. Our system can also deal with the time series images obtained on different occasions (long term change).The features of this paper are: (1) this paper deals with double time sequence images (short and long term); (2) an automatic blood vessel recognition algorithm is employed.  相似文献   
108.
109.
110.
Halophilic and non-halophilic bacteria subjected to osmotic downshock, from 0.7 M NaCl to deionized water, were examined for their survival, with the uptake and utilization of the cyclic amino acid ectoine, one of the representative compatible solutes, being taken into account. The uptake of ectoine added externally and survival of the cells were monitored as a function of incubation time in the presence and absence of NaCl. The halophilic Brevibacterium sp. JCM 6894 and B. epidermidis JCM 2593 actively accumulated ectoine regardless of the presence of NaCl, which led to cell survival. Brevibacterium casei JCM 2594 belonging to the same Brevibacterium species, however, revealed Na+-dependence of its uptake activity of ectoine. Non-halophilic Escherichia coli K-12 did not accumulate ectoine, and thereby this strain failed to survive irrespective of whether NaCl was present. The physiological meanings of the downshock procedure are discussed in connection with the uptake and the subsequent utilization of ectoine.  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