全文获取类型
收费全文 | 3709篇 |
免费 | 159篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 50篇 |
综合类 | 10篇 |
化学工业 | 1024篇 |
金属工艺 | 80篇 |
机械仪表 | 65篇 |
建筑科学 | 207篇 |
矿业工程 | 13篇 |
能源动力 | 65篇 |
轻工业 | 338篇 |
水利工程 | 15篇 |
石油天然气 | 1篇 |
无线电 | 233篇 |
一般工业技术 | 667篇 |
冶金工业 | 346篇 |
原子能技术 | 37篇 |
自动化技术 | 728篇 |
出版年
2023年 | 42篇 |
2022年 | 62篇 |
2021年 | 119篇 |
2020年 | 61篇 |
2019年 | 80篇 |
2018年 | 77篇 |
2017年 | 82篇 |
2016年 | 112篇 |
2015年 | 90篇 |
2014年 | 135篇 |
2013年 | 177篇 |
2012年 | 221篇 |
2011年 | 262篇 |
2010年 | 187篇 |
2009年 | 176篇 |
2008年 | 214篇 |
2007年 | 185篇 |
2006年 | 162篇 |
2005年 | 133篇 |
2004年 | 126篇 |
2003年 | 92篇 |
2002年 | 81篇 |
2001年 | 70篇 |
2000年 | 64篇 |
1999年 | 59篇 |
1998年 | 107篇 |
1997年 | 80篇 |
1996年 | 46篇 |
1995年 | 50篇 |
1994年 | 41篇 |
1993年 | 41篇 |
1992年 | 37篇 |
1991年 | 30篇 |
1990年 | 20篇 |
1989年 | 24篇 |
1988年 | 17篇 |
1987年 | 17篇 |
1985年 | 17篇 |
1984年 | 14篇 |
1983年 | 21篇 |
1982年 | 19篇 |
1981年 | 17篇 |
1980年 | 18篇 |
1979年 | 17篇 |
1978年 | 14篇 |
1977年 | 17篇 |
1976年 | 18篇 |
1975年 | 22篇 |
1974年 | 19篇 |
1973年 | 15篇 |
排序方式: 共有3879条查询结果,搜索用时 31 毫秒
1.
Magnetic Resonance Materials in Physics, Biology and Medicine - To investigate the value of using diffusion-weighted imaging (DWI) and intravoxel incoherent motion DWI (IVIM-DWI) to assess the... 相似文献
2.
Gökelma Mertol Einarsrud Kristian Etienne Tranell Gabriella Friedrich Bernd 《Metallurgical and Materials Transactions B》2020,51(2):850-860
Metallurgical and Materials Transactions B - The quality requirements of aluminum products are steadily increasing, and the presence of non-metallic inclusions have a large impact on the quality of... 相似文献
3.
Dr. Emrah Kara Dr. Nis Valentin Nielsen Bergrun Eggertsdottir Dr. Bernd Thiede Dr. Sandip M. Kanse Dr. Geir Åge Løset 《Chembiochem : a European journal of chemical biology》2020,21(13):1875-1884
We describe a novel, easy and efficient combinatorial phage display peptide substrate-mining method to map the substrate specificity of proteases. The peptide library is displayed on the pVII capsid of the M13 bacteriophage, which renders pIII necessary for infectivity and efficient retrieval, in an unmodified state. As capture module, the 3XFLAG was chosen due to its very high binding efficiency to anti-FLAG mAbs and its independency of any post-translational modification. This library was tested with Factor-VII activating protease (WT-FSAP) and its single-nucleotide polymorphism variant Marburg-I (MI)-FSAP. The WT-FSAP results confirmed the previously reported Arg/Lys centered FSAP cleavage site consensus as dominant, as well as reinforcing MI-FSAP as a loss-of-function mutant. Surprisingly, rare substrate clones devoid of basic amino acids were also identified. Indeed one of these peptides was cleaved as free peptide, thus suggesting a broader range of WT-FSAP substrates than previously anticipated. 相似文献
4.
5.
Non-standard fault models often require the application of two-pattern testing. A fully-automated approach for generating a multiple scan chain-based architecture is presented so that two-pattern test sets generated for the combinational core can be applied to the sequential circuit. Test time and area overhead constraints are considered. 相似文献
6.
Christian Stephan Bernd 《AEUE-International Journal of Electronics and Communications》2006,60(1):20-24
Security for ad hoc network environments has received a lot of attention as of today. Previous work has mainly been focussing on secure routing, fairness issues, and malicious node detection. However, the issue of introducing and conserving trust relationships has received considerably less attention. In this article, we present a scalable method for the use of public key certificates and their revocation in mobile ad hoc networks (MANETs). With the LKN-ad hoc security framework (LKN-ASF) a certificate management protocol has been introduced, bringing PKI technology to MANETs. In addition a performance analysis of two different revocation approaches for MANETs will be presented. 相似文献
7.
Claudia Popien Axel Kuepper Bernd Meyer 《Journal of Network and Systems Management》1994,2(4):383-400
New requirements of growing computer networks and information systems have an influence on extended client/server models with increased functionality. This forms the basis for service management in distributed systems which is realized by a service trading concept. This paper studies the requirements derived from the Open Distributed Processing (ODP) Reference Model in order to consider an open service market. Furthermore, it examines management possibilities for describing the service trading scenario. Because of similar architectures and properties ODP services, service offers, types, exporters and traders are mapped onto management components and modeled as managed objects. Therefore, the Guidelines for the Definition of Managed Objects (GDMO) are used. The final concept allows a precise and unambiguous study of the service trading scenario and provides means for exporting and importing of service offers in a distributed environment. 相似文献
8.
Intensive fertilizer use has led to nitrate contamination of groundwater in many areas. This article examines the possibility of removing nitrates through the construction of artificial wetlands. A pilot study conducted in Denmark has found that the method is effective and economical, at least for small waterworks, though further treatment is necessary before an acceptable microbiological water quality is attained. 相似文献
9.
10.
We determine the exact power of two-prover interactive proof systems introduced by Ben-Or, Goldwasser, Kilian, and Wigderson (1988). In this system, two all-powerful noncommunicating provers convince a randomizing polynomial time verifier in polynomial time that the inputx belongs to the languageL. We show that the class of languages having tow-prover interactive proof systems is nondeterministic exponential time.We also show that to prove membership in languages inEXP, the honest provers need the power ofEXP only.The first part of the proof of the main result extends recent techniques of polynomial extrapolation used in the single prover case by Lund, Fortnow, Karloff, Nisan, and Shamir.The second part is averification scheme for multilinearity of a function in several variables held by an oracle and can be viewed as an independent result onprogram verification. Its proof rests on combinatorial techniques employing a simple isoperimetric inequality for certain graphs: 相似文献