全文获取类型
收费全文 | 3425篇 |
免费 | 77篇 |
国内免费 | 13篇 |
专业分类
电工技术 | 58篇 |
综合类 | 2篇 |
化学工业 | 526篇 |
金属工艺 | 100篇 |
机械仪表 | 176篇 |
建筑科学 | 63篇 |
矿业工程 | 3篇 |
能源动力 | 130篇 |
轻工业 | 146篇 |
水利工程 | 37篇 |
石油天然气 | 9篇 |
无线电 | 590篇 |
一般工业技术 | 577篇 |
冶金工业 | 386篇 |
原子能技术 | 20篇 |
自动化技术 | 692篇 |
出版年
2023年 | 35篇 |
2022年 | 91篇 |
2021年 | 91篇 |
2020年 | 85篇 |
2019年 | 79篇 |
2018年 | 98篇 |
2017年 | 75篇 |
2016年 | 113篇 |
2015年 | 75篇 |
2014年 | 85篇 |
2013年 | 210篇 |
2012年 | 125篇 |
2011年 | 155篇 |
2010年 | 134篇 |
2009年 | 123篇 |
2008年 | 127篇 |
2007年 | 119篇 |
2006年 | 113篇 |
2005年 | 98篇 |
2004年 | 78篇 |
2003年 | 73篇 |
2002年 | 82篇 |
2001年 | 62篇 |
2000年 | 75篇 |
1999年 | 64篇 |
1998年 | 124篇 |
1997年 | 91篇 |
1996年 | 94篇 |
1995年 | 55篇 |
1994年 | 52篇 |
1993年 | 47篇 |
1992年 | 46篇 |
1991年 | 39篇 |
1990年 | 40篇 |
1989年 | 40篇 |
1988年 | 32篇 |
1987年 | 32篇 |
1986年 | 28篇 |
1985年 | 36篇 |
1984年 | 22篇 |
1983年 | 32篇 |
1982年 | 28篇 |
1981年 | 29篇 |
1980年 | 29篇 |
1979年 | 34篇 |
1978年 | 18篇 |
1977年 | 19篇 |
1976年 | 22篇 |
1975年 | 11篇 |
1973年 | 11篇 |
排序方式: 共有3515条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
Flynn P.J. Jain A.K. 《IEEE transactions on pattern analysis and machine intelligence》1991,13(10):1066-1075
BONSAI, a model-based 3D object recognition system, is described. It identifies and localizes 3D objects in range images of one or more parts that have been designed on a computer-aided-design (CAD) system. Recognition is performed via constrained search of the interpretation tree, using unary and binary constraints (derived automatically from the CAD models) to prune the search space. Attention is focused on the recognition procedure, but the model-building, image acquisition, and segmentation procedures are also outlined. Experiments with over 200 images demonstrate that the constrained search approach to 3D object recognition has an accuracy comparable to that of previous systems 相似文献
5.
6.
7.
ATM networks are quickly being adopted as backbones over various parts of the Internet. This article studies the dynamics and performance of the TCP/IP protocol over the ABR and UBR services of ATM networks. Specifically the buffering requirements in the ATM switches as well as the ATM edge devices. It is shown that with a good switch algorithm, ABR pushes congestion to the edges of the ATM network while UBR leaves it inside the ATM portion. As a result, the switch ABR buffer requirement for zero-packet-loss high-throughput TCP transmission is a sublinear function of the number of TCP connections 相似文献
8.
9.
We define and verify the utility of a pattern analysis procedure called sparse decomposition. This technique involves sequentially ``peeling' sparse subsets of patterns from a pattern set, where sparse subsets are sets of patterns which possess a certain degree of regularity or compactness as measured by a compactness measure c. If this is repeated until all patterns are deleted, then the sequence of decomposition ``layers' derived by this procedure provides a wealth of information from which inferences about the original pattern set may be made. A statistic P is derived from this information and is shown to be powerful in detecting clustering tendency for data in reasonably compact sampling windows. The test is applied to both synthetic and real data. 相似文献
10.
R. S. Mann S. K. Jain M. K. Dosi 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1977,27(1):198-204
The vapour phase oxidation of methanol to formaldehyde over molybdenum oxide, tungsten oxide and their mixtures has been investigated in an integral flow reactor at atmospheric pressure. The effect of several process variables on the conversion and yield were determined. A high conversion of 95.6% methanol with nearly 95% selectivity was obtained at 430°C. A rate expression has been derived from the kinetics of the reaction. 相似文献