全文获取类型
收费全文 | 2062篇 |
免费 | 69篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 20篇 |
综合类 | 3篇 |
化学工业 | 557篇 |
金属工艺 | 67篇 |
机械仪表 | 38篇 |
建筑科学 | 88篇 |
矿业工程 | 18篇 |
能源动力 | 27篇 |
轻工业 | 219篇 |
水利工程 | 3篇 |
石油天然气 | 11篇 |
无线电 | 127篇 |
一般工业技术 | 370篇 |
冶金工业 | 356篇 |
原子能技术 | 23篇 |
自动化技术 | 210篇 |
出版年
2023年 | 16篇 |
2021年 | 24篇 |
2020年 | 16篇 |
2019年 | 31篇 |
2018年 | 29篇 |
2017年 | 20篇 |
2016年 | 41篇 |
2015年 | 40篇 |
2014年 | 48篇 |
2013年 | 64篇 |
2012年 | 69篇 |
2011年 | 77篇 |
2010年 | 69篇 |
2009年 | 65篇 |
2008年 | 62篇 |
2007年 | 70篇 |
2006年 | 60篇 |
2005年 | 51篇 |
2004年 | 58篇 |
2003年 | 38篇 |
2002年 | 53篇 |
2001年 | 41篇 |
2000年 | 46篇 |
1999年 | 45篇 |
1998年 | 90篇 |
1997年 | 68篇 |
1996年 | 45篇 |
1995年 | 46篇 |
1994年 | 43篇 |
1993年 | 41篇 |
1992年 | 45篇 |
1991年 | 27篇 |
1989年 | 25篇 |
1988年 | 18篇 |
1987年 | 16篇 |
1985年 | 23篇 |
1984年 | 34篇 |
1983年 | 35篇 |
1982年 | 35篇 |
1981年 | 18篇 |
1980年 | 28篇 |
1979年 | 24篇 |
1978年 | 21篇 |
1977年 | 20篇 |
1976年 | 38篇 |
1975年 | 39篇 |
1974年 | 20篇 |
1973年 | 26篇 |
1971年 | 16篇 |
1970年 | 22篇 |
排序方式: 共有2137条查询结果,搜索用时 767 毫秒
991.
A 68-year old patient presented with increasing right-sided weakness, dysarthria, pyrexia and a deteriorating general condition. CT and MRI showed about 20 round hyperdense lesions with peripheral enhancement of contrast material up to 1.5 cm in diameter. Antibiotic triple-therapy using ceftriaxone, gentamycin and metronidazole for 39 days and followed by antibiotic double-therapy using ceftriaxone and metronidazole for a further 22 days resulted in a radiologically proven reduction of the abscesses to very small remnants which disappeared completely during the follow-up period of two years. Simultaneously the general condition of the patient improved significantly. Repeated attempts at isolation of bacteria, fungi, protozoa and parasites from a subdural empyema failed. The histological examination of an abscess, which was entirely removed on occipital craniotomy, showed a structure resembling actinomycosis. 相似文献
992.
A. Driessen H. J. W. M. Hoekstra F. C. Blom F. Horst G. J. M. Krijnen J. B. P. van Schoot P. V. Lambeck Th. J. A. Popma M. B. Diemeer 《Optical Materials》1998,9(1-4):329-333
Nonlinear polymers are promising materials for high speed active integrated optics devices. In this paper we evaluate the perspectives polymer based nonlinear optical devices can offer. Special attention is directed to the materials aspects. In our experimental work we applied mainly Akzo Nobel DANS side-chain polymer that exhibits large second and third order coefficients. This material has been characterized by third harmonic generation, z-scan and pump-probe measurements. In addition, various waveguiding structures have been used to measure the nonlinear absorption (two photon absorption) on a ps time-scale. Finally an integrated optics Mach Zehnder interferometer has been realized and evaluated. It is shown that the DANS side-chain polymer has many of the desired properties: the material is easily processable in high-quality optical waveguiding structures, has low linear absorption and its nonlinearity has a pure electronic origin. More materials research has to be done to arrive at materials with higher nonlinear coefficients to allow switching at moderate light intensity ( < 1 W peak power) and also with lower nonlinear absorption coefficients. 相似文献
993.
Heinrich Wolf Horst Gieser Detlef Bonfert Markus Hauser 《Microelectronics Reliability》2006,46(9-11):1587-1590
This work describes the investigation of the ESD susceptibility of submicron air gaps which are used e.g. in filter devices. The breakdown behaviour of the air gaps is analyzed in both the HBM (Human Body Model) time domain and the CDM (Charged Device Model) time domain. Transmission Line pulsing (TLP) reproduces the different failure signatures. Furthermore, the failure model itself is explained in detail. 相似文献
994.
This paper describes a new method that utilizes technology from soft computing to understand words after any OCR software system generated the proper database. First, the problem will be defined very precisely, and then, the algorithm for solving the problem of recognizing words will be presented. Finally, examples are provided to show how the algorithm is applied to recognize different types of words. © 2001 John Wiley & Sons, Inc. 相似文献
995.
利用Φ3mm透射电镜样品测量6N级铝和铝合金经760MeV质子辐照后电阻率或电阻值的变化。讨论了造成电阻率变化的主要原因。 相似文献
996.
G J van der Horst 《Journal of the Optical Society of America》1969,59(9):1213-1217
997.
998.
Hui-Min Huang John Horst Richard Quintero 《Journal of Intelligent and Robotic Systems》1992,5(1):79-99
The drive toward increased safety for coal miners has led to the development of computer-assisted methods of underground coal mining. The development of control architectures for the control of the movement of continuous mining machines (tramming control) is an important part of this overall effort. The tramming control algorithm design described is in concert with hierarchical architecture design principles developed at National Institute of Standards and Technology (NIST), referred to as the Real-time Control Systems (RCS) methodology. The algorithm design allows for the control of both cutting and free-space movement by a continuous mining machine and allows for a high degree of human operator interaction.This work is sponsored by the U.S. Bureau of Mines under Interagency Agreement (J0189027). 相似文献
999.
The Cyclic Cystine Ladder of Theta‐Defensins as a Stable,Bifunctional Scaffold: A Proof‐of‐Concept Study Using the Integrin‐Binding RGD Motif.
下载免费PDF全文
![点击此处可从《Chembiochem : a European journal of chemical biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Anne C. Conibear Dr. Alexander Bochen Dr. K. Johan Rosengren Petar Stupar Dr. Conan Wang Prof. Dr. Horst Kessler Prof. Dr. David J. Craik 《Chembiochem : a European journal of chemical biology》2014,15(3):451-459
Peptides have the specificity and size required to target the protein–protein interactions involved in many diseases. Some cyclic peptides have been utilised as scaffolds for peptide drugs because of their stability; however, other cyclic peptide scaffolds remain to be explored. θ‐Defensins are cyclic peptides from mammals; they are characterised by a cyclic cystine ladder motif and have low haemolytic and cytotoxic activity. Here we demonstrate the potential of the cyclic cystine ladder as a scaffold for peptide drug design by introducing the integrin‐binding Arg‐Gly‐Asp (RGD) motif into the θ‐defensin RTD‐1. The most active analogue had an IC50 of 18 nM for the αvβ3 integrin as well as high serum stability, thus demonstrating that a desired bioactivity can be imparted to the cyclic cystine ladder. This study highlights how θ‐defensins can provide a stable and conformationally restrained scaffold for bioactive epitopes in a β‐strand or turn conformation. Furthermore, the symmetry of the cyclic cystine ladder presents the opportunity to design peptides with dual bioactive epitopes to increase activity and specificity. 相似文献
1000.
Back Cover: The Integrin Ligand c(RGDf(NMe)Nal) Reduces Neointimal Hyperplasia in a Polymer‐Free Drug‐Eluting Stent System (ChemMedChem 7/2014)
下载免费PDF全文
![点击此处可从《ChemMedChem》网站下载免费的PDF全文](/ch/ext_images/free.gif)