全文获取类型
收费全文 | 6914篇 |
免费 | 747篇 |
国内免费 | 22篇 |
专业分类
电工技术 | 99篇 |
综合类 | 7篇 |
化学工业 | 1919篇 |
金属工艺 | 238篇 |
机械仪表 | 359篇 |
建筑科学 | 153篇 |
矿业工程 | 7篇 |
能源动力 | 228篇 |
轻工业 | 754篇 |
水利工程 | 44篇 |
石油天然气 | 13篇 |
无线电 | 1002篇 |
一般工业技术 | 1509篇 |
冶金工业 | 316篇 |
原子能技术 | 121篇 |
自动化技术 | 914篇 |
出版年
2024年 | 17篇 |
2023年 | 99篇 |
2022年 | 179篇 |
2021年 | 275篇 |
2020年 | 215篇 |
2019年 | 243篇 |
2018年 | 315篇 |
2017年 | 303篇 |
2016年 | 376篇 |
2015年 | 275篇 |
2014年 | 374篇 |
2013年 | 522篇 |
2012年 | 485篇 |
2011年 | 589篇 |
2010年 | 397篇 |
2009年 | 423篇 |
2008年 | 402篇 |
2007年 | 311篇 |
2006年 | 245篇 |
2005年 | 184篇 |
2004年 | 161篇 |
2003年 | 182篇 |
2002年 | 160篇 |
2001年 | 129篇 |
2000年 | 105篇 |
1999年 | 95篇 |
1998年 | 105篇 |
1997年 | 73篇 |
1996年 | 73篇 |
1995年 | 49篇 |
1994年 | 44篇 |
1993年 | 35篇 |
1992年 | 24篇 |
1991年 | 34篇 |
1990年 | 24篇 |
1989年 | 21篇 |
1988年 | 15篇 |
1987年 | 12篇 |
1986年 | 5篇 |
1985年 | 18篇 |
1984年 | 14篇 |
1983年 | 12篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1974年 | 5篇 |
1973年 | 4篇 |
排序方式: 共有7683条查询结果,搜索用时 15 毫秒
41.
Deborah C. Blaine John D. Gurosik Seong Jin Park Randall M. German Donald F. Heaney 《Metallurgical and Materials Transactions A》2006,37(3):715-720
Sintering experiments with various molybdenum powders are rationalized using a master sintering curve concept that collapses
density, grain size, or other parameters onto a single curve. In this case, the integral work of sintering is developed and
customized for different green densities. Construction of the master sintering curve is described to show how the curve can
be normalized with respect to green density effects. Various grades of molybdenum for metal injection molding and die compaction
are included in the analysis, processed over a range of heating cycles. Die-compacted samples of varying green densities are
used to illustrate the efficacy of the new, normalized master sintering curve concept. Sintering cycle optimization is one
possible outcome from this analysis. 相似文献
42.
Coating of 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 (PMN–PT) relaxor ferroelectrics by a sol–gel method is followed by growth of epitaxial SrRuO3 (SRO) metallic oxide electrodes on SrTiO3 (STO) single-crystal substrate by pulsed laser deposition. High-quality PMN–PT films on SRO with preferred growth orientation were successfully fabricated by controlling the operation parameters. Structural properties of relaxor ferroelectric PMN–PT thin films on SRO/STO substrates have been studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). In-plane and out-of-plane alignments of the heterostructure are confirmed and the structural twinning of the materials are also revealed. 相似文献
43.
44.
45.
Paulussen-Hoogeboom Marja C.; Stams Geert Jan J. M.; Hermanns Jo M. A.; Peetsma Thea T. D. 《Canadian Metallurgical Quarterly》2007,43(2):438
This meta-analytic review (k = 62 studies; N = 7,613 mother-child dyads) shows that effect sizes for the association between child negative emotionality and parenting were generally small and were moderated by sample and measurement characteristics. The association between more child negative emotionality and less supportive parenting was relatively strong in lower socioeconomic status families, reversed in higher socioeconomic status families, and limited to studies with relatively high percentages of participants from ethnic minorities and studies using parent report to assess negative emotionality. Higher levels of child negative emotionality were associated with more restrictive control in samples with less than 75% 1st-born children, as well as in infants and preschoolers, and in studies using parent report or composite measures to assess both negative emotionality and restrictive parenting. Finally, more child negative emotionality was associated with less inductive control. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
46.
47.
Motion based object tracking with mobile camera 总被引:4,自引:0,他引:4
Kyu Won Lee Seong Won Ryu Soo Jong Lee Kyu Tae Park 《Electronics letters》1998,34(3):256-258
An efficient algorithm which detects and tracks a moving object is proposed. The global motion energy caused by camera movement is eliminated by finding the maximal matching position with the cross-correlation value between two consecutive frames using the spiral scanning technique. The region of a moving object is segmented exactly by combining the results of the temporal derivatives and edge map from one image, and the actual centroid of the moving object is determined as the mid-point of the cumulative distribution of the projection profile of the region 相似文献
48.
This paper presents the results of the Réseau futé (smart net) project, the goal of which is to use distributed AI and multi-agent techniques for network management and supervision. More precisely, these techniques have been applied to the partial automation of the dynamic processing (what is known about a network is always incomplete and can change at any time) of alarms and of various event notifications received by network management platforms. The system that we propose is able for example to automatically handle some alarms or to filter events of no-interest for a given operator. To achieve this goal, an assistant, or interface agent according to the model proposed by Patti Maes [MK93], has been realized. The goal of the assistant is first to learn, by observation, the behavior of the network supervision operator and second to reproduce such a behavior when the conditions in which the behavior has been learned are detected again. The learned information are stored using chronicles [Gha94]. A chronicle is a data-structure allowing programmers to represent sequences of events while taking temporal knowledge into account. Our assistant has been implemented and tested within Magenta which is a program, written in Smalltalk, that simulates (in a simplified way) a network management platform. This program respects roughly the gdmo and cmis standards. 相似文献
49.
50.
Yoo‐Seong Kim Woong‐Sik Kim Hak‐Nyun Choi Tae‐Geum Koh Yong‐Seog Kim 《Journal of the Society for Information Display》2007,15(3):199-204
Abstract— Among various barrier‐rib manufacturing processes, the mold‐pattern‐transfer method has potential to reduce processing cost as well as the manufacture of high‐resolution pixels. In this study, the effects of major processing variables of the mold‐pattern‐transfer process on the formation of air‐trapped pores within barrier ribs were examined. The results indicated that with an optimum combination of the processing variables, barrier ribs without trapped defects can be produced, demonstrating the possibility of reducing the number of processing steps and costs of barrier ribs. 相似文献