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   528篇
  免费   46篇
  国内免费   61篇
电工技术   70篇
综合类   48篇
化学工业   68篇
金属工艺   1篇
机械仪表   6篇
建筑科学   17篇
矿业工程   3篇
能源动力   3篇
轻工业   18篇
水利工程   3篇
石油天然气   12篇
武器工业   6篇
无线电   123篇
一般工业技术   35篇
冶金工业   46篇
原子能技术   4篇
自动化技术   172篇
  2024年   3篇
  2023年   7篇
  2022年   16篇
  2021年   16篇
  2020年   15篇
  2019年   7篇
  2018年   6篇
  2017年   11篇
  2016年   15篇
  2015年   17篇
  2014年   34篇
  2013年   28篇
  2012年   42篇
  2011年   47篇
  2010年   45篇
  2009年   27篇
  2008年   21篇
  2007年   32篇
  2006年   37篇
  2005年   36篇
  2004年   18篇
  2003年   25篇
  2002年   27篇
  2001年   12篇
  2000年   16篇
  1999年   9篇
  1998年   8篇
  1997年   6篇
  1996年   5篇
  1995年   2篇
  1994年   5篇
  1993年   6篇
  1992年   3篇
  1991年   6篇
  1990年   3篇
  1989年   2篇
  1987年   2篇
  1985年   4篇
  1984年   3篇
  1983年   1篇
  1982年   2篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1976年   1篇
  1965年   1篇
  1961年   1篇
  1958年   1篇
排序方式: 共有635条查询结果,搜索用时 31 毫秒
11.
针对ARPS算法中初始预测运动矢量不够精确并且ARPS算法针对不同宏块采用相同搜索策略的问题,在深入研究ARPS算法原理的基础上,提出一种基于自适应扁平搜索模板的新的快速运动估计算法.本文在算法的初始预测运动矢量、算法提前终止准则等方面提出了新的观点和方法,同时针对物体的不同运动趋势采用不同的搜索模板.实验证明,本文提出的改进算法在不影响图像编码效率的前提下较大地降低了计算复杂度.  相似文献   
12.
A model (consisting of rv-systems), a core programming language (for developing rv-programs), several specification and analysis techniques appropriate for modeling, programming and reasoning about interactive computing systems have been recently introduced by Stefanescu using register machines and space-time duality, see [Stefanescu, G. Interactive systems with registers and voices. Fundamenta Informaticae 73 (2006), 285–306. (Early draft, School of Computing, National University of Singapore, July 2004.)]. After that, Dragoi and Stefanescu have developed structured programming techniques for rv-systems and their verification, see, e.g., [Dragoi, C., and G. Stefanescu. Structured programming for interactive rv-systems. Institute of Mathematics of the Romanian Academy, IMAR Preprint 9/2006, Bucharest 2006. Dragoi, C., and G. Stefanescu. Towards a Hoare-like logic for structured rv-programs. Institute of Mathematics of the Romanian Academy, IMAR Preprint 10/2006, Bucharest, 2006. Dragoi, C., and G. Stefanescu. Implementation and verification of ring termination detection protocols using structured rv-programs. Annals of University of Bucharest, Mathematics-Informatics Series, 55 (2006), 129–138. Dragoi, C., and G. Stefanescu. Structured interactive programs with registers and voices and their verification. Draft, Bucharest, January 2007. Dragoi, C., and G. Stefanescu. On compiling structured interactive programs with registers and voices. In: “Proc. SOFSEM 2008,” 259–270. LNCS 4910, Springer, 2008.].In the present paper a kernel programming language AGAPIA v0.1 for interactive systems is introduced. The language contains definitions for complex spatial and temporal data, arithmetic and boolean expressions, modules, and while-programming statements with their temporal, spatial, and spatio-temporal versions. In AGAPIA v0.1 one can write programs for open processes located at various sites and having their temporal windows of adequate reaction to the environment. The main technical part of the paper describes a typing system for AGAPIA v0.1 programs.  相似文献   
13.
For the blind recognition of Turbo codes in information interception, the recognition algorithm of turbo codes on trellis termination fall into following two parts. In coding structure recognition, turbo codes on trellis termination is defined as linear block codes, so the blind recognition of code length and start is achieved by analyzing the rank of codes matrix with a different number of columns and a different start; In encoder parameter recognition, by comparing the sequence matrix's column vector before and after interleaving and determining the decision threshold, the influence of error codes whose number is lower than the decision threshold is removed, and consequently, the problem of poor fault-tolerant performance in the traditional interleaving mode recognition method is solved. Simulation shows that the correct percentage of recognition is higher than 80% at 10-3 BER, and confirms the validity and reliability of the algorithm.  相似文献   
14.
朱玉璧 《安徽电力》2005,22(3):11-15
某电厂一台600MW机组在常规大修中,发现定子绕组多处水电接头漏水,检查发现水盒和空心导线等处泄漏,采取现场修理的办法,成功消除了漏水缺陷。本文详细介绍漏水处理的经过。  相似文献   
15.
We discuss several post-processing issues in molecular dynamics (MD) calculation of lattice thermal conductivity using the Green–Kubo formula. For crystals with high thermal conductivity such as SiC, converting the MD raw data on heat current fluctuations into thermal conductivity result is non-trivial. One can accelerate the process using Fast Fourier Transform and the spectral method. A few mathematical subtleties are cleared up. Due to finite data length, integration of the correlation function must be terminated before noise takes over; two termination criteria are proposed which give reasonable results for crystalline β-SiC. A simple solvable model that illustrates the above points and can be used for code-checking is presented.  相似文献   
16.
对于传统数据采集系统。由于每次采样占用DSP(Digital Signal Process)的时间,影响其数据处理及运算速度。在馈电终端单元的设计中。我们将FPGA(Field Programmable Gate Arrav)芯片与A/D芯片(MAXl25)相结合,实现成批数据的采集.并在同一FPGA芯片上实现了数字测频电路与系统控制电路。详述了上述功能的实现方法和仿真时序图。实验结果表明,在馈电终端单元中采用FPGA技术。降低了硬件外部连接的复杂程度,提高了系统的整体性能。  相似文献   
17.
With the fast development of network applications, there are more asynchronous distributed systems and more requirements for fault tolerance. Asynchrony means there is no upper bound for either message transfer or operation execution. Active replication is an effective means to enhance fault tolerant capability in distributed systems. A key component in a system is replicated and all the replicas make up of a fault-tolerant group. Members in such a group execute all client requests and then re…  相似文献   
18.
一种Agent数据库系统框架及其规则并行算法   总被引:11,自引:0,他引:11  
张茂元  卢正鼎 《软件学报》2004,15(8):1157-1164
面向对象方法描述的对象是被动的,与主动机制存在矛盾,不能很好地定义分布式主动数据库中对象的功能和特性.分布式主动数据库中的主动规则还带来了终止性、合流性的问题.首先分析面向对象方法的局限性,将Agent技术、分布式数据库、主动数据库相结合,给出一种面向Agent的分布式主动数据库系统框架.然后在这个框架基础上,提出扩展事件规则图方法和改进的Coffman-Graham规则并行算法,并分析它们的性能.分析结果表明,前者在一定程度上解决了数据库系统的终止性问题,后者在保持合流性的基础上提高了规则并行处理效率.这个框架对研究Agent技术在分布式主动数据库中的应用有一定的启示.  相似文献   
19.
We consider Facebook unfriending as a form of relationship termination with negative emotional and cognitive consequences. Specifically, ruminative and negative emotional responses are examined via an online survey of adult Facebook users who were unfriended. These responses were positively related to each other and to Facebook intensity. Rumination was positively predicted by using Facebook to connect with existing contacts and was more likely when the unfriender was a close partner. Participants also responded with greater rumination and negative emotion when they knew who unfriended them, when they thought they were unfriended for Facebook-related reasons, and when participants initiated the Facebook friend request. The contribution of these exploratory findings to our growing understanding of negative relational behaviors on Facebook are discussed.  相似文献   
20.
在分析研究H.264视频编码标准推荐的运动估计核心算法EPZS的基础上,针对该算法运动估计实时性不足的缺点,提出一种对EPZS算法进行起始搜索窗口中心点和计算终止条件判断标准的改进方法,在H.264编码器的参考模型JM10.1中,选择5个测试序列进行实验。实验结果表明,改进后的算法与原算法相比,在重建图像质量和码率接近的情况下,运动估计时间平均节省了29.314%,降低了算法的复杂度,提高了编码的实时性。  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