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   3220篇
  免费   80篇
  国内免费   24篇
电工技术   99篇
综合类   39篇
化学工业   774篇
金属工艺   72篇
机械仪表   134篇
建筑科学   118篇
矿业工程   23篇
能源动力   93篇
轻工业   299篇
水利工程   32篇
石油天然气   12篇
武器工业   2篇
无线电   291篇
一般工业技术   443篇
冶金工业   323篇
原子能技术   45篇
自动化技术   525篇
  2024年   24篇
  2023年   15篇
  2022年   50篇
  2021年   72篇
  2020年   39篇
  2019年   66篇
  2018年   67篇
  2017年   45篇
  2016年   60篇
  2015年   67篇
  2014年   86篇
  2013年   175篇
  2012年   139篇
  2011年   211篇
  2010年   195篇
  2009年   205篇
  2008年   214篇
  2007年   182篇
  2006年   147篇
  2005年   167篇
  2004年   100篇
  2003年   108篇
  2002年   105篇
  2001年   66篇
  2000年   57篇
  1999年   53篇
  1998年   84篇
  1997年   66篇
  1996年   49篇
  1995年   38篇
  1994年   37篇
  1993年   52篇
  1992年   33篇
  1991年   25篇
  1990年   27篇
  1989年   16篇
  1988年   23篇
  1987年   19篇
  1986年   9篇
  1985年   22篇
  1984年   16篇
  1983年   22篇
  1982年   9篇
  1981年   18篇
  1980年   11篇
  1979年   6篇
  1978年   3篇
  1977年   5篇
  1976年   6篇
  1973年   3篇
排序方式: 共有3324条查询结果,搜索用时 0 毫秒
991.
992.
    
Abstract— The fabrication and demonstration of field‐sequential‐color (FSC) LCDs using modules of narrow‐gap twisted‐nematic (NTN) LCDs with and without doping of newly synthesized PγCyD‐ZrO2 nanoparticles is reported. Two types of FSC‐LCDs are demonstrated: one is a direct multiplexed NTN‐LCD and the other is TFT driven. The advantages of FSC‐LCDs include their high legibility even under direct sunlight, and the mechanism for the doping of nanoparticles in LCDs is discussed.  相似文献   
993.
    
Abstract— Organic light‐emitting‐device (OLED) devices are very promising candidates for flexible‐display applications because of their organic thin‐film configuration and excellent optical and video performance. Recent progress of flexible‐OLED technologies for high‐performance full‐color active‐matrix OLED (AMOLED) displays will be presented and future challenges will be discussed. Specific focus is placed on technology components, including high‐efficiency phosphorescent OLED technology, substrates and backplanes for flexible displays, transparent compound cathode technology, conformal packaging, and the flexibility testing of these devices. Finally, the latest prototype in collaboration with LG. Phillips LCD, a flexible 4‐in. QVGA full‐color AMOLED built on amorphous‐silicon backplane, will be described.  相似文献   
994.
    
Proteins secreted from specific cancer cells have a high potential for use as tumor markers. We identified secreted proteins produced by 15 different carcinoma cell lines grown in serum-free medium using MS/MS. Proneurotensin/neuromedin N (proNT/NMN) was found in conditioned medium from four of seven small cell lung carcinoma cell lines but not from eight nonsmall cell lung carcinoma cell lines. These results indicate proNT/NMN has potential as a specific tumor marker of small cell lung carcinoma.  相似文献   
995.
    
Abstract— A double‐monochromator spectroradiometer with a photon‐counting detector will be described. The system captures spectroradiometric data with near‐perfect linearity over six decades of intensity and with wavelength uncertainties of under 0.05 nm. It enables accurate measurement of spectral radiance data and small‐area contrast with an uncertainty less than 0.002 in chromaticity (x,y) and 2% in luminance for a typical CRT spectrum.  相似文献   
996.
    
If we were to have a Grid infrastructure for visualization, what technologies would be needed to build such an infrastructure, what kind of applications would benefit from it, and what challenges are we facing in order to accomplish this goal? In this survey paper, we make use of the term ‘visual supercomputing’ to encapsulate a subject domain concerning the infrastructural technology for visualization. We consider a broad range of scientific and technological advances in computer graphics and visualization, which are relevant to visual supercomputing. We identify the state‐of‐the‐art technologies that have prepared us for building such an infrastructure. We examine a collection of applications that would benefit enormously from such an infrastructure, and discuss their technical requirements. We propose a set of challenges that may guide our strategic efforts in the coming years.  相似文献   
997.
    
Abstract— A flexible‐printed‐cable (FPC) free liquid‐crystal‐display (LCD) panel by using a capacitive‐coupling technique has been developed. A QQVGAeight‐color image was successfully displayed for the first time without attaching any signal or power cables to the panel. The receiving circuitry and capacitive‐coupling electrodes were integrated on the LCD panel using a low‐temperature polysilicon (LTPS) fabrication process. In the proposed digital coding method, the receiving circuit converts derivative waveform signals via the capacitive coupling to conventional logic‐level signals. The maximum data rate of 2.4‐Mbps × 3ch (RGB) was achieved. In addition, LTPS low‐capacitance diode bridge and regulator enabled us to obtain stable DC power of 2.4 mW on the panel from the AC‐power signal. This study is the first step towards integrating the wireless‐communication function on the display panel to achieve a high‐value‐added flat‐panel display (FPD).  相似文献   
998.
    
We propose a proof system for reasoning on certain specifications of secure authentication systems. For this purpose, a new logic, sequence-indexed linear-time temporal logic (SLTL), is obtained semantically from standard linear-time temporal logic (LTL) by adding a sequence modal operator that represents a sequence of symbols. By this sequence modal operator, we can appropriately express message flows between clients and servers and states of servers in temporal reasoning. A Gentzen-type sequent calculus for SLTL is introduced, and the completeness and cut-elimination theorems for it are proved. SLTL is also shown to be PSPACE-complete and embeddable into LTL.  相似文献   
999.
为实现在局部遮挡、光线变化等复杂背景下的目标跟踪,提出一种基于梯度方向直方图(HOG)与多实例在线学习的目标跟踪算法.利用已标定目标图像的HOG特征空间,结合局部二值模式(LBP)描述方法获取特征向量,构建初始随机蕨检测算子,采用随机多尺度采样方法跟踪每一帧的目标位置和尺寸,并基于多实例在线学习框架,通过检测到的目标样本以及附近的背景样本在线更新检测算子.将该算法与OnlineB oostingTracker,MILTracker等在线学习目标跟踪算法在多个标准视频序列中进行比较,实验结果表明,该算法在局部遮挡和光照变化的环境下具有较好的跟踪稳定性,但在抗目标旋转方面有待优化.  相似文献   
1000.
    
The transition among multiple charging states of a semiconductor's localized intrinsic/impurity defects is considered as phase transitions, and the concept of transition Gibbs free energy level (TGFEL) is proposed. Dependence of the cross section of TGFEL on its charge state is discussed. Introduction of TGFEL to replace acti- vation energy has fundamentally important consequences for semiconductor physics and devices. TGFEL involves entropy. What is to be included and not included in the entropy term consistently for all defect levels is an unre- solved open question, related to correct interpretation of various experimental data associated with various defect levels. This work is a first step towards resolving this question.  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