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   984篇
  免费   37篇
  国内免费   2篇
电工技术   32篇
化学工业   190篇
金属工艺   48篇
机械仪表   34篇
建筑科学   6篇
能源动力   41篇
轻工业   60篇
水利工程   2篇
石油天然气   2篇
无线电   95篇
一般工业技术   262篇
冶金工业   152篇
原子能技术   8篇
自动化技术   91篇
  2023年   11篇
  2022年   16篇
  2021年   21篇
  2020年   18篇
  2019年   20篇
  2018年   35篇
  2017年   36篇
  2016年   44篇
  2015年   13篇
  2014年   43篇
  2013年   94篇
  2012年   38篇
  2011年   67篇
  2010年   57篇
  2009年   43篇
  2008年   36篇
  2007年   42篇
  2006年   39篇
  2005年   36篇
  2004年   21篇
  2003年   20篇
  2002年   22篇
  2001年   16篇
  2000年   15篇
  1999年   14篇
  1998年   27篇
  1997年   16篇
  1996年   21篇
  1995年   13篇
  1994年   17篇
  1993年   9篇
  1992年   17篇
  1991年   9篇
  1990年   9篇
  1989年   5篇
  1988年   10篇
  1987年   10篇
  1986年   4篇
  1985年   5篇
  1984年   4篇
  1983年   2篇
  1982年   4篇
  1980年   5篇
  1979年   2篇
  1978年   3篇
  1976年   3篇
  1973年   3篇
  1972年   2篇
  1970年   1篇
  1969年   1篇
排序方式: 共有1023条查询结果,搜索用时 312 毫秒
1.
Neural Processing Letters - The uncertainty caused mainly by the deficiency of precision and data, artificial/human-made errors, information accessed from expert opinions or very miniature size of...  相似文献   
2.
Multimedia Tools and Applications - A secret sharing scheme partitions a secret into a set of shares and distributes them among the eligible participants, with each participant receiving one share...  相似文献   
3.
Microsystem Technologies - This paper represents low power and high speed design issues of Hamming code generation and error detection circuit using complementary metal oxide semiconductor (CMOS)...  相似文献   
4.
A three dimensional, transient model is developed for studying heat transfer, fluid flow and mass transfer for the case of a single-pass laser surface alloying process. The numerical study is performed in a co-ordinate system fixed to the laser which moves with a constant scanning speed. The coupled momentum, energy and species conservation equations are solved using a finite volume technique. Phase change processes are modelled using a fixed-grid enthalpy-porosity technique, which is capable of predicting the continuously evolving solid-liquid interface. The three-dimensional model is able to predict the species concentration distribution inside the molten pool during alloying, as well as in the entire cross section of the solidified alloy. Corresponding experimental results show a good qualitative agreement with the numerical predictions with regard to pool shape and final composition distribution.  相似文献   
5.
6.
The present study concerns the effect of copper additions on the microstructural evolution and mechanical properties of directly quenched Ti–B steels. Ti and B are added as microalloying elements with an aim of achieving adequate austenite hardenability and Cu is added to retard the austenite (γ) → ferrite (α) transformation. Therefore, the microalloying and Cu additions together allow the transformation of austenite to occur at a lower temperature, resulting in a finer microstructure containing martensitic constituents. The direct-quenching route is adopted with an aim of facilitating the nucleation of the constituent phases from the deformed austenite. In order to circumvent the hot-shortness due to the Cu addition, 0.79 wt% Ni has been added to one of the 1.5 wt% Cu microalloyed steels. The present study has demonstrated that the Ni-containing 1.5Cu–Ti–B steel is capable of providing an attractive combination of strength and ductility comparable to the high strength varieties of HSLA steels in directly quenched condition.  相似文献   
7.
The early stages in the formation of α1 plates in the ordered β′ matrix of a Cu-39 pct Zn alloy have been studied with transmission electron microscopy (TEM). The early stage plates were found to be free of stacking faults. Their contrast features are indeed those normally expected from small coherent plates. Electron microdiffraction confirms that these plates have the 9R structure characteristic of α1 with the same lattice parameters and orientation relationships reported by previous investigators at much later stages of growth. Similarly, the 9R structure was disordered, even though it was formed in an ordered matrix, again repeating previous results obtained at a later stage of growth. These results further support the view that the α1 Cu-Zn plates form by a diffusion-controlled mechanism. This article is based on a presentation made at the Pacific Rim Conference on the “Roles of Shear and Diffusion in the Formation of Plate-Shaped Transformation Products,” held December 18-22, 1992, in Kona, Hawaii, under the auspices of ASM INTERNATIONAL’S Phase Transformations Committee.  相似文献   
8.
S Chattopadhyay  P P Das 《Sadhana》1993,18(2):349-364
Reconstruction of an original continuous curve and the estimation of its parameters from the digitized version of the curve is a challenging problem, as quantization always causes some loss of information. In this paper, we have developed a scheme for reconstruction which is applicable to a class of curves having at the most two parameters. The class of curves for which the scheme works has also been characterized. We have shown that for one-parameter curves the exact domain of values of the parameter can be obtained. But in the two-parameter case, only the smallest rectangle containing the domain can be realised. The distinctive feature of our scheme is that it provides a unified approach to solve the reconstruction and the domain-finding problem for a class of curves.  相似文献   
9.
Creep energy dissipation (CED) due to crack tip creep zone is determined under steady state conditions for centre cracked thin specimen of 1.25CrO.5Mo steel, with different widths and crack length to width ratios. The creep energy rate increases when the increment in crack length Δa increases and the slope increases with increase in aspect ratio a/W and decreases with increase in width W.  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