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   421篇
  免费   11篇
电工技术   12篇
化学工业   101篇
金属工艺   6篇
机械仪表   24篇
建筑科学   2篇
矿业工程   2篇
能源动力   16篇
轻工业   19篇
水利工程   4篇
石油天然气   12篇
无线电   33篇
一般工业技术   115篇
冶金工业   46篇
原子能技术   4篇
自动化技术   36篇
  2024年   2篇
  2022年   8篇
  2021年   15篇
  2020年   5篇
  2019年   11篇
  2018年   10篇
  2017年   9篇
  2016年   15篇
  2015年   12篇
  2014年   14篇
  2013年   25篇
  2012年   24篇
  2011年   25篇
  2010年   20篇
  2009年   27篇
  2008年   18篇
  2007年   24篇
  2006年   15篇
  2005年   15篇
  2004年   15篇
  2003年   8篇
  2002年   8篇
  2001年   3篇
  2000年   6篇
  1999年   5篇
  1998年   6篇
  1996年   4篇
  1995年   3篇
  1993年   6篇
  1992年   2篇
  1990年   5篇
  1989年   2篇
  1988年   7篇
  1987年   3篇
  1984年   5篇
  1982年   4篇
  1980年   2篇
  1978年   5篇
  1977年   2篇
  1976年   2篇
  1974年   2篇
  1973年   3篇
  1972年   4篇
  1970年   5篇
  1968年   2篇
  1967年   2篇
  1966年   4篇
  1965年   1篇
  1964年   1篇
  1959年   1篇
排序方式: 共有432条查询结果,搜索用时 0 毫秒
1.
In the present work the formation of the interface between polycrystalline silver and thin films of titanium oxide was studied with photoelectron spectroscopy (XPS, UPS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Titanium oxide was deposited stepwise on 100 nm thick silver films by reactive magnetron sputtering allowing to study the evolution of the interface formation process. The process involves two steps: formation of thin layer of silver oxide and subsequent growth of the TiO2 film. For better understanding of the silver oxidation process, pure silver films were exposed to a low temperature Ar/O plasma for different time intervals providing a possibility to investigate early stages of the oxide film growth.  相似文献   
2.
Neuronets are considered for processing data on the state of a potentially hazardous object after an emergency. An example is given of processing the data on the state of a potentially hazardous object in increments.Translated from Izmeritel’naya Tekhnika, No. 3, pp. 6–8, March, 2005.  相似文献   
3.
Worsening of the environmental situation in many regions of Russia in recent decades is to a great degree due to production and refining of oil and gas with a high hydrogen sulfide content. Industrial methods of utilization of hydrogen sulfide are extremely irrational: it is either burned in flares or used for production of sulfur whose quality and quantity pose new problems related to its use.  相似文献   
4.
5.
6.
Phase formation in the SrF2–LaF3 system was studied at temperatures ranging from 300°C to 450°C using nitrate flux. The solubility of LaF3 in SrF2 decreases with decreasing temperature. The equilibrium width of the solid solution region Sr1−xLaxF2+x at 400°C, it is 44.6 ± 0.4 mol% LaF3 (x = 0.446), at 350°C — 38.3 ± 0.7 mol% LaF3 (x = 0.383), and decreases almost to zero at 300°C.  相似文献   
7.
In interactive theorem proving practice a significant amount of time is spent on unsuccessful proof attempts of wrong conjectures. An automatic method that reveals them by generating finite counter examples would offer an extremely valuable support for a proof engineer by saving his time and effort. In practice, such counter examples tend to be small, so usually there is no need to search for big instances. Most definitions of functions or predicates on infinite structures do not preserve the semantics if a transition to arbitrary finite substructures is made. We propose constraints which guarantee a correct axiomatization on finite structures and present an approach which uses the Alloy Analyzer to generate finite instances of theories in the theorem prover KIV. It is evaluated on the library of basic data types as well as on some challenging case studies in KIV. The technique is implemented using the Kodkod constraint solver which is a successor of Alloy.  相似文献   
8.
A considerable body of literature attests to the significance of internal controls; however, little is known on how the clustering of accounting databases can function as an internal control procedure. To explore this issue further, this paper puts forward a semi-supervised tool that is based on self-organizing map and the IASB XBRL Taxonomy. The paper validates the proposed tool via a series of experiments on an accounting database provided by a shipping company. Empirical results suggest the tool can cluster accounting databases in homogeneous and well-separated clusters that can be interpreted within an accounting context. Further investigations reveal that the tool can compress a large number of similar transactions, and also provide information comparable to that of financial statements. The findings demonstrate that the tool can be applied to verify the processing of accounting transactions as well as to assess the accuracy of financial statements, and thus supplement internal controls.  相似文献   
9.
Hepatocellular carcinoma (HCC) is a global healthcare challenge, which affects more than 815,000 new cases every year. Activated hepatic stellate cells (aHSCs) remain the principal cells that drive HCC onset and growth. aHSCs suppress the anti-tumor immune response through interaction with different immune cells. They also increase the deposition of the extracellular matrix proteins, challenging the reversion of fibrosis and increasing HCC growth and metastasis. Therapy for HCC was reported to activate HSCs, which could explain the low efficacy of current treatments. Conversely, recent studies aimed at the deactivation of HSCs show that they have been able to inhibit HCC growth. In this review article, we discuss the role of aHSCs in HCC pathophysiology and therapy. Finally, we provide suggestions for the experimental implementation of HSCs in HCC therapies.  相似文献   
10.
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