全文获取类型
收费全文 | 2196篇 |
免费 | 96篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 37篇 |
综合类 | 6篇 |
化学工业 | 649篇 |
金属工艺 | 56篇 |
机械仪表 | 46篇 |
建筑科学 | 128篇 |
矿业工程 | 10篇 |
能源动力 | 46篇 |
轻工业 | 135篇 |
水利工程 | 9篇 |
无线电 | 148篇 |
一般工业技术 | 391篇 |
冶金工业 | 193篇 |
原子能技术 | 29篇 |
自动化技术 | 414篇 |
出版年
2023年 | 19篇 |
2022年 | 33篇 |
2021年 | 66篇 |
2020年 | 37篇 |
2019年 | 38篇 |
2018年 | 45篇 |
2017年 | 42篇 |
2016年 | 79篇 |
2015年 | 58篇 |
2014年 | 72篇 |
2013年 | 103篇 |
2012年 | 116篇 |
2011年 | 149篇 |
2010年 | 116篇 |
2009年 | 104篇 |
2008年 | 115篇 |
2007年 | 97篇 |
2006年 | 113篇 |
2005年 | 80篇 |
2004年 | 84篇 |
2003年 | 55篇 |
2002年 | 44篇 |
2001年 | 43篇 |
2000年 | 35篇 |
1999年 | 38篇 |
1998年 | 65篇 |
1997年 | 56篇 |
1996年 | 31篇 |
1995年 | 24篇 |
1994年 | 27篇 |
1993年 | 26篇 |
1992年 | 25篇 |
1991年 | 21篇 |
1990年 | 19篇 |
1989年 | 15篇 |
1988年 | 12篇 |
1987年 | 15篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 9篇 |
1983年 | 11篇 |
1982年 | 13篇 |
1981年 | 12篇 |
1980年 | 14篇 |
1979年 | 11篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 14篇 |
1974年 | 17篇 |
排序方式: 共有2297条查询结果,搜索用时 15 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.
Zdeněk Slanina Filip Uhlík Lipiao Bao Takeshi Akasaka Xing Lu Ludwik Adamowicz 《Fullerenes, Nanotubes and Carbon Nanostructures》2020,28(7):565-570
AbstractRelative populations of four energy-lowest IPR (isolated-pentagon-rule) isomers of Eu@C86 are computed using the Gibbs energy based on characteristics from density functional theory calculations (M06-2X/3-21G?~?SDD entropy term, M06-2X/6-31G*~SDD or B2PLYP(D)/6-31G*~SDD energetics). The calculations confirm that the recently isolated Eu@C1(7)-C86 species is a major isomer in a relevant temperature region. Relationship to the empty C86 cages is discussed, too. 相似文献
5.
6.
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
7.
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
8.
The focus of this paper lies in the practical aspects of voice over IP communication. VoIP configurations in the H.323 standard will be presented briefly. Following that, the fundamental protocol procedure of H.323 communication will be briefly explained. A further part of the paper will address the subject QoS (quality of service), and present the common measurement methods used in QoS. Results gained from experiments conducted in a VoIP environment will then follow. The investigations concentrate primarily on the load behavior of voice packets in relation to important parameters of this service. The results obtained are presented and evaluated in diagrams. The paper concludes with a summary. 相似文献
9.
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
10.