全文获取类型
收费全文 | 5722篇 |
免费 | 638篇 |
国内免费 | 290篇 |
专业分类
电工技术 | 335篇 |
综合类 | 382篇 |
化学工业 | 1011篇 |
金属工艺 | 338篇 |
机械仪表 | 382篇 |
建筑科学 | 454篇 |
矿业工程 | 160篇 |
能源动力 | 193篇 |
轻工业 | 375篇 |
水利工程 | 115篇 |
石油天然气 | 243篇 |
武器工业 | 74篇 |
无线电 | 694篇 |
一般工业技术 | 680篇 |
冶金工业 | 365篇 |
原子能技术 | 79篇 |
自动化技术 | 770篇 |
出版年
2024年 | 45篇 |
2023年 | 124篇 |
2022年 | 239篇 |
2021年 | 369篇 |
2020年 | 243篇 |
2019年 | 181篇 |
2018年 | 234篇 |
2017年 | 217篇 |
2016年 | 228篇 |
2015年 | 271篇 |
2014年 | 359篇 |
2013年 | 357篇 |
2012年 | 445篇 |
2011年 | 418篇 |
2010年 | 375篇 |
2009年 | 314篇 |
2008年 | 255篇 |
2007年 | 236篇 |
2006年 | 236篇 |
2005年 | 189篇 |
2004年 | 164篇 |
2003年 | 134篇 |
2002年 | 131篇 |
2001年 | 107篇 |
2000年 | 106篇 |
1999年 | 115篇 |
1998年 | 96篇 |
1997年 | 88篇 |
1996年 | 61篇 |
1995年 | 58篇 |
1994年 | 55篇 |
1993年 | 36篇 |
1992年 | 31篇 |
1991年 | 19篇 |
1990年 | 20篇 |
1989年 | 17篇 |
1988年 | 14篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 3篇 |
排序方式: 共有6650条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Chih-Wea Wang Chi-Feng Wu Jin-Fu Li Cheng-Wen Wu Tony Teng Kevin Chiu Hsiao-Ping Lin 《Journal of Electronic Testing》2002,18(6):637-647
In this paper we propose a novel built-in self-test (BIST) design for embedded SRAM cores. Our contribution includes a compact and efficient BIST circuit with diagnosis support and an automatic diagnostic system. The diagnosis module of our BIST circuit can capture the error syndromes as well as fault locations for the purposes of repair and fault/failure analysis. In addition, our design provides programmability for custom March algorithms with lower hardware cost. The combination of the on-line programming mode and diagnostic system dramatically reduces the effort in design debugging and yield enhancement. We have designed and implemented test chips with our BIST design. Experimental results show that the area overhead of the proposed BIST design is only 2.4% for a 128 KB SRAM, and 0.65% for a 2 MB one. 相似文献
5.
国外农用非织造布覆盖材料的应用 总被引:4,自引:1,他引:3
非织造布在现代农业生产中占有重要地位 ,非织造布作为农用覆盖材料在柑橘、草莓、茶叶、花卉、水稻和玉米育苗以及人参栽培等多方面应用较为广泛 ,本文对国外农用非织造布覆盖材料的特点、性能以及应用情况作了介绍 相似文献
6.
数字图书馆是图书馆发展的主要方向。在我国,数字图书馆建设存在一些问题。探索解决问题的方法和途径,是摆在我们面前的一项任务。 相似文献
7.
Toughening mechanism for a rubber-toughened epoxy resin with rubber/matrix interfacial modification 总被引:1,自引:0,他引:1
For a rubber-toughened piperidine-DGEBA epoxy resin, the interface between the rubber particle and the epoxy resin matrix was modified by an epoxide end-capped carboxyl terminated butadiene and acrylonitrile random copolymer (CTBN). The end-capping epoxides used were a rigid diglycidyl ether of bisphenol-A (Epon 828), a short-chain flexible diglycidyl ether of propylene glycol (DER 736), and a long-chain flexible diglycidyl ether of propylene glycol (DER 732). The microstructures and the fracture behaviour of these rubber-modified epoxy resins were studied by transmission electron microscopy and scanning electron microscopy. Their thermal and mechanical properties were also investigated. In the rubber-modified epoxy resins, if the added CTBNs were end-capped by a flexible diglycidyl ether of propylene glycol (DER 732 or DER 736) before curing, the interfacial zone of the undeformed rubber particle, the degree of cavitation of the cavitated rubber particle on the fracture surface and the fracture energy of the toughened epoxy resin were all significantly increased. The toughening mechanism based on cavitation and localized shear yielding was considered and a mechanism for the interaction between cavitation and localized shear yielding that accounts for all the observed characteristics is proposed. 相似文献
8.
Li-Pen Yuan Chin-Chi Teng Sung-Mo Kang 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》1998,6(1):65-73
In this paper, we present a new statistical technique for estimation of average power dissipation in digital circuits. The present parametric statistical technique estimates the average power based on the assumption that the power distribution can be characterized by a preassumed function. Large error can incur when the assumption is not met. On the other hand, the existing nonparametric technique, although accurate, is too conservative and requires a large sample size in order to achieve convergence. For a good tradeoff between simulation accuracy and computational efficiency, we propose a new nonparametric technique using the properties of the order statistics. It is generally applicable to any type of circuit irrespective of its power distribution function. Compared to the existing nonparametric technique, it is much more computationally efficient since it requires a much smaller sample size to achieve the same accuracy specification. This new technique is implemented in the distribution-independent power estimation tool (DIPE). DIPE is empirically demonstrated to be more robust and accurate than the parametric technique 相似文献
9.
Business process redesign (BPR) has been widely touted as a means for leveraging the power of information technology to change business processes radically, resulting in substantial improvements in organizational effectiveness and efficiency. This study represents an early attempt at examining the strategic nature of the phenomenon. Because BPR is radical change and has the ability to alter both the competitive and operational nature of the corporation, it is critical that BPR be coordinated with corporate strategy. Through a survey of information system executives, the relationships between corporate competitive strategy and three types of BPR – intrafunctional, interfunctional and interorganizational – were examined. It was found that organizations following a cost strategy tended to do more BPR projects on interfunctional processes. Furthermore, the positive effect of a cost strategy on interfunctional BPR was found to be strengthened by the degree of integration of IS and business planning. It was also found that while interorganizational BPR was not related to a specific strategy, it was strongly related directly with IS–business planning integration. 相似文献
10.
Large elevated steel silos for the storage of bulk solids generally consist of a cylindrical vessel above a conical discharge hopper supported on a cylindrical skirt. The cone–cylinder–skirt transition junction is subject to a large circumferential compressive force which is derived from the horizontal component of the meridional tension in the conical hopper, so either a ring is provided or the shell walls are locally thickened to strengthen the junction. Extensive theoretical studies have examined the buckling and collapse strengths of these junctions, leading to theoretically based design proposals. However, no previous experimental study on steel silo transition junctions has been reported due to the considerable difficulties associated with testing these thin-shell junctions at model scale. This paper presents the results of a series of tests on cone–cylinder–skirt–ring junctions in steel silos under simulated bulk solid loading. In addition to the presentation of test results including geometric imperfections and failure behavior, the determination of buckling modes and loads based on displacement measurements is examined in detail. 相似文献