全文获取类型
收费全文 | 6567篇 |
免费 | 226篇 |
国内免费 | 13篇 |
专业分类
电工技术 | 96篇 |
综合类 | 32篇 |
化学工业 | 1702篇 |
金属工艺 | 133篇 |
机械仪表 | 113篇 |
建筑科学 | 376篇 |
矿业工程 | 23篇 |
能源动力 | 132篇 |
轻工业 | 506篇 |
水利工程 | 45篇 |
石油天然气 | 2篇 |
无线电 | 431篇 |
一般工业技术 | 1302篇 |
冶金工业 | 972篇 |
原子能技术 | 56篇 |
自动化技术 | 885篇 |
出版年
2023年 | 45篇 |
2022年 | 58篇 |
2021年 | 99篇 |
2020年 | 84篇 |
2019年 | 86篇 |
2018年 | 99篇 |
2017年 | 113篇 |
2016年 | 165篇 |
2015年 | 121篇 |
2014年 | 182篇 |
2013年 | 295篇 |
2012年 | 262篇 |
2011年 | 376篇 |
2010年 | 284篇 |
2009年 | 288篇 |
2008年 | 292篇 |
2007年 | 283篇 |
2006年 | 270篇 |
2005年 | 241篇 |
2004年 | 210篇 |
2003年 | 167篇 |
2002年 | 146篇 |
2001年 | 120篇 |
2000年 | 115篇 |
1999年 | 130篇 |
1998年 | 209篇 |
1997年 | 152篇 |
1996年 | 140篇 |
1995年 | 114篇 |
1994年 | 116篇 |
1993年 | 128篇 |
1992年 | 92篇 |
1991年 | 68篇 |
1990年 | 82篇 |
1989年 | 78篇 |
1988年 | 79篇 |
1987年 | 71篇 |
1986年 | 63篇 |
1985年 | 55篇 |
1984年 | 67篇 |
1983年 | 50篇 |
1982年 | 61篇 |
1981年 | 58篇 |
1980年 | 40篇 |
1979年 | 40篇 |
1978年 | 39篇 |
1977年 | 43篇 |
1976年 | 63篇 |
1975年 | 53篇 |
1973年 | 37篇 |
排序方式: 共有6806条查询结果,搜索用时 15 毫秒
1.
Wolfgang Wendler 《电子产品世界》2006,(17):129-130
与美国同行争分夺秒抢占市场先机不同,欧洲测量仪器厂商Rohde&Schwarz公司的产品策略则相对稳健,他们的产品更专注于功能的多样化 相似文献
2.
3.
Ohne Zusammenfassung 相似文献
4.
While Beck asserts that agility is only possible through greater discipline on the part of everyone involved, Boehm counters that you don't broaden the definition of "discipline" by rejecting parts of it. Yet, from inside extreme programming, it seems that the only way to achieve the desired results is to view the world in 'both-and" terms instead of "either-or" terms. 相似文献
5.
6.
On the suitability of agricultural by-products for the manufacture of granular activated carbon 总被引:1,自引:0,他引:1
An investigation of several agricultural by-products revealed that their suitability for activated carbon production is not determined by general material-specific features (elemental composition) but by type-specific features. A coarse-cellular structure (as in wood), which is indicated by porosities of the raw materials higher than 35% is disadvantageous. A specific change in the properties of cokes (porosity, density, hardness) is possible by varying the conditions of pyrolysis. By rapid heating in the pyrolysis step, for instance, macroporous residues are produced. Temperature and burnoff have the greatest influence on the quality of the activated carbon during the activation step. Of the investigated materials, coconut shells yield granular activated carbon of the highest quality. The following order of suitability of raw materials for activated carbon production was established: coconut shells> peach stones> plum stones> hazelnut shells> walnut shells> cherry stones. 相似文献
7.
A sensitive method for measurement of the volume of blood flow through the skin, based on the kinetics of reheating after localised cooling, is described in this paper. This method has been used to study the tuberculin reaction as a model of cutaneous delayed-type hypersensitivity (DHS) in man. Over the positive reaction there is accelerated reheating similar in kinetics and extent to that seen after maximal hyperaemia induced by intradermal injection of histamine or prostaglandin E2. The earlier phase of reheating (10-100 s) is more dependent on blood flow, whereas the later phase (100-300 s) is apparently more dependent on non-perfusion heat exchange mechanisms, including conduction. The reheat kinetic method is largely dependent on blood flow in the deep dermal vessels (diameter > 50 microns), whereas the alternative approach of measurement of the velocity of flow of erythrocytes in the microcirculation by laser Doppler (LD) flowmetry gives results biased towards the most superficial dermal circulation. Previous studies with LD flowmetry have shown that the blood velocity is greatest at the centre of weak and strong reactions, while in the most intense reactions it is raised at the centre but maximal at the periphery (central relative slowing, CRS) raising the possibility of central ischaemia. The reheat kinetics approach has now indicated that the deep dermal circulation is not impaired in CRS reactions. It is concluded that there must be partial obstruction of the parts of the microcirculation communicating between the deep and superficial dermal plexuses, presumably from the accumulation of exudate oedema in the most intense tuberculin reactions. 相似文献
8.
The choice of a highly resistive substrate for silicon millimeter-wave integrated circuits (SIMMWIC) imposed by the requirement of low RF-substrate losses requires the adaptation of a CMOS process on float zone silicon (FZ). A comparison of n- and p-channel devices realized on high resistivity substrate (p-type, 5000 Ω·cm) and standard CMOS substrates (CZ, n-type, 4-6 Ω·cm) is given. Using careful process design, we obtained device characteristics on FZ-substrates that are closely similar to those on standard material, thus allowing direct transfer of existing circuit designs 相似文献
9.
10.
Sven Beyer Christian Jacobi Daniel Kröning Dirk Leinenbach Wolfgang J. Paul 《International Journal on Software Tools for Technology Transfer (STTT)》2006,8(4-5):411-430
In the verified architecture microprocessor (VAMP) project we have designed, functionally verified, and synthesized a processor
with full DLX instruction set, delayed branch, Tomasulo scheduler, maskable nested precise interrupts, pipelined fully IEEE
compatible dual precision floating point unit with variable latency, and separate instruction and data caches. The verification
has been carried out in the theorem proving system PVS. The processor has been implemented on a Xilinx FPGA.
A shorter version of this article with the title “Instantiating uninterpreted functional units and memory system: functional
verification of the VAMP” appeared in [8]. The work reported here was done while all the authors were with Saarland University. 相似文献