首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1319篇
  免费   66篇
  国内免费   2篇
电工技术   31篇
综合类   1篇
化学工业   302篇
金属工艺   22篇
机械仪表   22篇
建筑科学   106篇
矿业工程   1篇
能源动力   27篇
轻工业   119篇
水利工程   6篇
石油天然气   3篇
无线电   113篇
一般工业技术   225篇
冶金工业   159篇
原子能技术   23篇
自动化技术   227篇
  2023年   13篇
  2022年   22篇
  2021年   32篇
  2020年   13篇
  2019年   16篇
  2018年   24篇
  2017年   20篇
  2016年   41篇
  2015年   27篇
  2014年   38篇
  2013年   68篇
  2012年   61篇
  2011年   105篇
  2010年   71篇
  2009年   69篇
  2008年   77篇
  2007年   79篇
  2006年   62篇
  2005年   59篇
  2004年   48篇
  2003年   33篇
  2002年   33篇
  2001年   22篇
  2000年   19篇
  1999年   24篇
  1998年   50篇
  1997年   42篇
  1996年   28篇
  1995年   25篇
  1994年   15篇
  1993年   25篇
  1992年   13篇
  1991年   4篇
  1990年   11篇
  1989年   6篇
  1988年   6篇
  1987年   4篇
  1986年   11篇
  1985年   5篇
  1984年   5篇
  1983年   5篇
  1982年   6篇
  1981年   4篇
  1980年   3篇
  1978年   6篇
  1977年   4篇
  1976年   9篇
  1974年   6篇
  1972年   4篇
  1937年   3篇
排序方式: 共有1387条查询结果,搜索用时 15 毫秒
1.
The biorelevant PyFALGEA oligopeptide ligand, which is selective towards the epidermal growth factor receptor (EGFR), has been successfully employed as a substrate in magnetic resonance signal amplification by reversible exchange (SABRE) experiments. It is demonstrated that PyFALGEA and the iridium catalyst IMes form a PyFALGEA:IMes molecular complex. The interaction between PyFALGEA:IMes and H2 results in a ternary SABRE complex. Selective 1D EXSY experiments reveal that this complex is labile, which is an essential condition for successful hyperpolarization by SABRE. Polarization transfer from parahydrogen to PyFALGEA is observed leading to significant enhancement of the 1H NMR signals of PyFALGEA. Different iridium catalysts and peptides are inspected to discuss the influence of their molecular structures on the efficiency of hyperpolarization. It is observed that PyFALGEA oligopeptide hyperpolarization is more efficient when an iridium catalyst with a sterically less demanding NHC ligand system such as IMesBn is employed. Experiments with shorter analogues of PyFALGEA, that is, PyLGEA and PyEA, show that the bulky phenylalanine from the PyFALGEA oligopeptide causes steric hindrance in the SABRE complex, which hampers hyperpolarization with IMes. Finally, a single-scan 1H NMR SABRE experiment of PyFALGEA with IMesBn revealed a unique pattern of NMR lines in the hydride region, which can be treated as a fingerprint of this important oligopeptide.  相似文献   
2.
International Journal of Computer Vision -  相似文献   
3.
4.
This paper gives a tutorial overview of basic approaches for model validation and model structure determination.Work partially supported by the Swedish Research Council for Engineering Sciences under contract 98-654.  相似文献   
5.
In recent years, a wide range of generalized barycentric coordinates has been suggested. However, all of them lack control over derivatives. We show how the notion of barycentric coordinates can be extended to specify derivatives at control points. This is also known as Hermite interpolation. We introduce a method to modify existing barycentric coordinates to higher order barycentric coordinates and demonstrate, using higher order mean value coordinates, that our method, although conceptually simple and easy to implement, can be used to give easy and intuitive control at interactive frame rates over local space deformations such as rotations.  相似文献   
6.
Grey box identification refers to the practice of identifying dynamical systems in model structures exploiting partial prior information. This contribution reviews a method for stochastic grey box identification and surveys experiences and lessons of applying it to a number of industrial processes. Issues to be addressed include advantages and costs of introducing stochastics into the model, the question of what contribution must be expected from the model designer as opposed to what can be formalized in computer algorithms, and an outlook on future plans to resolve present shortcomings.  相似文献   
7.
A neurostimulator application-specific integrated circuit (ASIC) with scalable circuitry that can stimulate 14 channels, has been developed for an epi-retinal vision prosthesis. This ASIC was designed to allow seven identical units to be connected to control up to 98 channels, with the ability to stimulate 14 electrodes simultaneously. The neurostimulator forms part of a vision prosthesis, designed to restore vision to patients who have lost their sight due to retinal diseases such as retinitis pigmentosa and macular degeneration. For charge balance, the neurostimulator was designed to stimulate with current sources and sinks operating together, and with the ability to drive a hexagonal mosaic of electrodes to reduce the electrical crosstalk that occurs when multiple bipolar stimulation sites are active simultaneously. A hexagonal mosaic of electrodes surrounds each stimulation site and has been shown to effectively isolate each site, increasing the ability to inject localized independent charge into multiple regions simultaneously.  相似文献   
8.
An automotive engine oil viscosity sensor   总被引:1,自引:0,他引:1  
For the evaluation of the condition of automotive engine oil, the oil's viscosity is one of the most important parameters. Using microacoustic viscosity sensors, an oil-viscosity measurement can be performed on-board. In this contribution, we discuss the behavior of the viscosity of engine oil, its temperature dependence, and the resulting representation in terms of output signals of microacoustic viscosity sensors. These considerations are illustrated by means of measurement results obtained for used oil samples, which have been obtained from test cars and fresh oil samples out of different viscosity classes. Finally, the detection of the viscosity increase due to soot contamination is demonstrated.  相似文献   
9.
The Munich Community Health Service (Medical School-Service Department) conducted an alcohol prevention project in ten public secondary schools. The 423 pupils (11-17 years of age) filled in a questionnaire on alcohol and discussed it afterwards under the guidance of a school physician and a teacher using guideline information. The results of the survey are presented in this paper. Additionally, suggestions for transferring the results to conceptualize and carry out preventive measures are made. The results indicate that the first experience with alcohol occurred early in life. One-fifth of the sample had already tried alcohol at the age of six. Immediate effects of alcohol (e.g. state of drunkenness) were experienced by 35.7 percent of the sample group. Kiosks, shops, and beverage stores were named most frequently as sources for alcohol. The sources of social support varied with respect to sex and age. With increasing age of the children, parents were contacted less frequently whereas the role of peers increased. The present results supply possible paths of action for the development of successful prevention strategies, e.g. by pointing out the early age of onset as well as specific sources of alcohol acquisition.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号