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   952篇
  免费   95篇
  国内免费   8篇
电工技术   28篇
综合类   1篇
化学工业   182篇
金属工艺   28篇
机械仪表   46篇
建筑科学   35篇
能源动力   24篇
轻工业   40篇
水利工程   19篇
石油天然气   1篇
无线电   189篇
一般工业技术   195篇
冶金工业   99篇
原子能技术   7篇
自动化技术   161篇
  2023年   17篇
  2022年   13篇
  2021年   24篇
  2020年   19篇
  2019年   35篇
  2018年   34篇
  2017年   36篇
  2016年   37篇
  2015年   24篇
  2014年   29篇
  2013年   72篇
  2012年   42篇
  2011年   64篇
  2010年   49篇
  2009年   56篇
  2008年   30篇
  2007年   46篇
  2006年   43篇
  2005年   45篇
  2004年   31篇
  2003年   19篇
  2002年   19篇
  2001年   16篇
  2000年   10篇
  1999年   18篇
  1998年   34篇
  1997年   23篇
  1996年   26篇
  1995年   9篇
  1994年   6篇
  1993年   16篇
  1992年   6篇
  1991年   11篇
  1989年   5篇
  1988年   10篇
  1987年   7篇
  1986年   7篇
  1985年   11篇
  1984年   3篇
  1982年   7篇
  1981年   5篇
  1980年   3篇
  1977年   4篇
  1976年   3篇
  1972年   2篇
  1969年   5篇
  1966年   3篇
  1965年   3篇
  1958年   2篇
  1957年   2篇
排序方式: 共有1055条查询结果,搜索用时 46 毫秒
91.
An oligonucleotide-peptide conjugate, having dual binding capability for a designated RNA, was designed. The peptide portion of the conjugate interacts with a folded domain in the RNA, whereas the oligonucleotide portion hybridizes with a nearby single-stranded region in the RNA. The dual specificity was proven in a model HIV-1 TAR RNA system using an RNase H cleavage assay to assess antisense binding to this RNA. The peptide portion of the conjugate was shown to confer increased specificity on the oligonucleotide.  相似文献   
92.
Expansion of games industry came in modern life, accompanied with innovative features in a game controller. Nowadays mobile industry is booming with the expansion of the variety of novel technologies, such as the use of 3D accelerometer sensors, high resolution cameras, the capability of connecting to wireless networks and so on. Therefore, a smartphone can be added with the game control functions to become a mobile game controller. In this paper, we propose the design and implementation of making a mobile phone as a game controller using User Datagram Protocol socket programming. This system is developed by Java 2 Standard Edition and Google Android Software Development Kits which has already provided sensor and multi-touch APIs. We successfully realize a reconfigurable mobile game controller on a mobile smartphone to interact with the existing digital games by mapping control functions on the server. Acceptable performance is shown to validate the effectiveness of our solution.  相似文献   
93.
94.
Zinc niobium oxide (ZnNb2O6) thin films were grown on ITO/glass substrate by sol-gel process. Microstructure and surface morphology of the ZnNb2O6 thin films have been studied by X-ray diffraction and scanning electron microscopy. Optical properties of the ZnNb2O6 thin films were obtained by UV-visible recording spectrophotometer. The dependence of the microstructure, optical transmittance spectra, optical band gap on annealing temperature was also investigated.  相似文献   
95.
96.
A TiO(2) nanotube layer with a periodic structure is used as a photonic crystal to greatly enhance light harvesting in TiO(2) nanotube-based dye-sensitized solar cells. Such a tube-on-tube structure fabricated by a single-step approach facilitates good physical contact, easy electrolyte infiltration, and efficient charge transport. An increase of over 50% in power conversion efficiency is obtained in comparison to reference cells without a photonic crystal layer (under similar total thickness and dye loading).  相似文献   
97.
A solar dryer for drying herbs and spices using hot air from roof-integrated solar collectors was developed. The dryer is a bin type with a rectangular perforated floor. The bin has a dimension of 1.0 m×2.0 m×0.7 m. Hot air is supplied to the dryer from fiberglass-covered solar collectors, which also function as the roof of a farmhouse. The total area of the solar collectors is 72 m2. To investigate its performance, the dryer was used to dry four batches of rosella flowers and three batches of lemon-grasses during the year 2002–2003. The dryer can be used to dry 200 kg of rosella flowers and lemon-grasses within 4 and 3 days, respectively. The products being dried in the dryer were completely protected from rains and insects and the dried products are of high quality. The solar air heater has an average daily efficiency of 35% and it performs well both as a solar collector and a roof of a farmhouse.  相似文献   
98.
A pulse energy at 100MHz is verified to be able to determine the normal and abnormal discharge during electrical discharge machining (EDMing). A band pass filter is designed to detect the energy at this frequency, and can verify which discharge pulses are normal and abnormal, respectively. A field programmable gate array (FPGA) is used to implement the discharge detection circuit, including detection of the time of ignition (Td) and discharge high‐energy. Function analysis is used to design the proportional (P) Td controller to allow the bounded variation of reference input and the feedback signals. Energy of about 100MHz can be maintained within a specified pulse width by regulating the position of the electrode, including a slight regulation and jump motion. The rate of erosion during the roughing and finishing of a die‐sinking EDM is confirmed to demonstrate the improvements obtained by the EDMing.  相似文献   
99.
100.
Interactive programming is a convenient programming style that supports fast prototyping and debugging but often results in a loss of modularity and security. This article addresses the problem of supporting reliable and modular interactive programming. A module system designed for interactive use is introduced. This module system supports separate compilation and automatic updating of module interfaces during program development. It also allows the programmer to obtain a fresh program state for reliable testing, eliminating the need to reload an entire program.A preliminary version of this article was presented at the 1992 ACM Conference on Lisp and Functional Programming.  相似文献   
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