首页 | 官方网站   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   11688篇
  免费   750篇
  国内免费   837篇
工业技术   13275篇
  2024年   27篇
  2023年   104篇
  2022年   205篇
  2021年   234篇
  2020年   171篇
  2019年   121篇
  2018年   104篇
  2017年   158篇
  2016年   181篇
  2015年   225篇
  2014年   522篇
  2013年   433篇
  2012年   670篇
  2011年   756篇
  2010年   729篇
  2009年   784篇
  2008年   867篇
  2007年   951篇
  2006年   937篇
  2005年   892篇
  2004年   706篇
  2003年   690篇
  2002年   481篇
  2001年   403篇
  2000年   315篇
  1999年   219篇
  1998年   175篇
  1997年   162篇
  1996年   128篇
  1995年   141篇
  1994年   129篇
  1993年   101篇
  1992年   79篇
  1991年   68篇
  1990年   43篇
  1989年   45篇
  1988年   34篇
  1987年   24篇
  1986年   21篇
  1985年   33篇
  1984年   31篇
  1983年   18篇
  1982年   10篇
  1981年   14篇
  1980年   12篇
  1979年   10篇
  1978年   11篇
  1977年   10篇
  1975年   15篇
  1971年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
一种高效的图像细化算法在焊缝跟踪中的应用   总被引:2,自引:0,他引:2  
针对焊缝跟踪图像处理的特点,研究了二值化后的图像如何进一步细化的方法;采用先对焊缝的边缘进行提取,然后从垂直于焊缝的方向进行扫描的方法,取两条边缘的中点,即是焊缝的骨架;结果表明:此算法能准确地对一幅二值图细化,满足焊缝跟踪中图像处理的要求;这种算法的突出特点是计算量小,处理速度快,非常适合于焊缝的实时处理跟踪,而且不用改写算法,既适合于黑色背景白色图像,也适合于白色背景黑色图像.本算法通过推导得到四条处理准则,在遵循这几条处理准则的基础上逐点扫描图像,按照准则来确定目标点的删除与保留,达到细化的最终目的.  相似文献   
52.
Repeated reference creates strong expectations in addressees that a speaker will continue to use the same expression for the same object. The authors investigate the root reason for these expectations by comparing a cooperativeness-based account (Grice, 1975) with a simpler consistency-based account. In two eye-tracking experiments, the authors investigated the expectations underlying the effect of precedents on comprehension. The authors show that listeners expect speakers to be consistent in their use of expressions even when these expectations cannot be motivated by the assumption of cooperativeness. The authors conclude that though this phenomenon seems to be motivated by cooperativeness, listeners' expectation that speakers be consistent in their use of expressions is governed by a general expectation of consistency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
53.
When describing scenes, speakers gaze at objects while preparing their names (Z. M. Griffin & K. Bock, 2000). In this study, the authors investigated whether gazes to referents occurred in the absence of a correspondence between visual features and word meaning. Speakers gazed significantly longer at objects before intentionally labeling them inaccurately with the names of similar things (e.g., calling a horse a dog) than when labeling them accurately. This held for grammatical subjects and objects as well as agents and patients. Moreover, the time spent gazing at a referent before labeling it with a novel word or accurate name was similar and decreased as speakers gained experience using the novel word. These results suggest that visual attention in speaking may be directed toward referents in the absence of any association between their visual forms and the words used to talk about them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
54.
55.
Designing a distributed application is an extremely complex task. Proper facilities for prototyping distributed applications can be useful in evaluating a design, and also in understanding the effect of different parameters on the performance of an application. We describe a language for prototyping distributed applications, that supports different communication primitives with specified delay, and provides primitives to aid debugging and evaluation. Our environment for executing distributed programs supports heterogeneous computation in which processes can execute on different hardware. Different source languages can be used for coding different modules of the processes. The system has a centralized control and monitoring facility which is based on the Suntools window system.  相似文献   
56.
多任务调度算法在单片机控制系统中的应用   总被引:1,自引:1,他引:0  
为了满足单片机控制系统的复杂要求 ,提出了多任务调度算法 ,通过与单任务程序结构的对比和分析 ,详细说明了多任务调度算法的实现 ,指出了应用该算法的必要性 ,并且以科研生产的实例说明其具体应用。  相似文献   
57.
本文介绍了一个基于计算机的多路信号采集、实时显示及报警系统 ,由于该系统以计算机、数据采集卡为基本硬件来完成各项仪器功能 ,因此它属于虚拟仪器的范畴。虚拟仪器是现代测量测试仪器的发展方向 ,软件系统是虚拟仪器的核心。虚拟仪器技术的优势在于可由用户定义自己的专用仪器系统 ,且功能灵活 ,很容易构建 ,所以应用越来越广泛。本文介绍了基于虚拟仪器技术的传感器信号测量及报警系统 ,给出了它的硬件构成 ,用VC++作为软件开发语言的设计方法和优点  相似文献   
58.
介绍了一种用于冰箱检测的新型测试系统,并在WIN98环境下用VB6.0实现该系统软件。该系统可以同时对四台冰箱的温度参数及其中一台冰箱的耗电量进行检测,该系统具有成本低,性能稳定的优点。  相似文献   
59.
Reviews the book, Language in the Americas by Joseph H. Greenberg (1987). Greenberg's work on universals of language has crossed disciplinary boundaries to become known to many psychologists interested in language. His equally important work in language classification, of which Language in the Americas is one part, remains unfamiliar to psychologists. This book is a pioneering work in that it is the first genetic classification of the indigenous languages of both North and South America. Greenberg maintains that all of the languages of the Americas belong to three families: Eskimo-Aleut, Na-Dene, and a family that he has named Amerind. This assertion is both important and controversial; the controversy lies in the grouping of most of the languages including all of those of South and Central America into the Amerind family. Most of Language in the Americas consists of the Amerind etymological dictionary, arranged so that the reader can assess lexical similarities within and between subgroups. Greenberg's discussion is informed, articulate, profound, and to the point. He draws on relevant sources and examples from diverse fields of knowledge. The depth and breadth of his scholarship and the clarity of his presentation create a work that is an intellectual pleasure to read. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
60.
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-23

京公网安备 11010802026262号