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   2669篇
  免费   205篇
  国内免费   190篇
电工技术   103篇
综合类   222篇
化学工业   94篇
金属工艺   46篇
机械仪表   196篇
建筑科学   161篇
矿业工程   31篇
能源动力   37篇
轻工业   31篇
水利工程   32篇
石油天然气   35篇
武器工业   28篇
无线电   269篇
一般工业技术   155篇
冶金工业   197篇
原子能技术   11篇
自动化技术   1416篇
  2024年   1篇
  2023年   9篇
  2022年   33篇
  2021年   34篇
  2020年   30篇
  2019年   31篇
  2018年   33篇
  2017年   52篇
  2016年   88篇
  2015年   90篇
  2014年   157篇
  2013年   161篇
  2012年   180篇
  2011年   239篇
  2010年   179篇
  2009年   175篇
  2008年   194篇
  2007年   238篇
  2006年   194篇
  2005年   140篇
  2004年   129篇
  2003年   129篇
  2002年   118篇
  2001年   73篇
  2000年   55篇
  1999年   64篇
  1998年   35篇
  1997年   31篇
  1996年   18篇
  1995年   21篇
  1994年   24篇
  1993年   10篇
  1992年   10篇
  1991年   5篇
  1990年   6篇
  1989年   9篇
  1988年   6篇
  1987年   9篇
  1986年   4篇
  1985年   7篇
  1984年   4篇
  1983年   7篇
  1982年   13篇
  1981年   8篇
  1980年   4篇
  1979年   3篇
  1978年   1篇
  1976年   3篇
排序方式: 共有3064条查询结果,搜索用时 15 毫秒
91.
为了解决多机器人系统分布式控制问题,借鉴人体内分泌系统研究的理论成果,提出基于晶格的人工内分泌系统模型.该模型以环境晶格化为基础,以细胞智能化为依托,以累加激素为纽带,以靶细胞为导向,能够适应外环境的持续变化,保持内环境的相对稳定,充分体现人体内分泌系统的自组织和自修复特性.实验结果表明,无需复杂的集中控制策略,基于该...  相似文献   
92.
在当今社会,传统的教学方式和手段使学生对C#.NET这门课程普遍感觉枯燥无味,难以达到良好的教学效果,只有采用良好的教学模式才能够激发学生学习的主动性、能够激发学生学习的热情。该文谈谈怎样使用案例教学培养学生的兴趣,培养学生的动手实践能力和创造能力,掌握C#.NET编程技术。  相似文献   
93.
计算机平面设计行业作为知识型的服务产业,在竞争日益激烈的商业社会中发挥着举足轻重的作用。Photoshop(以下简称PS)是一门实践性很强的课程,使用传统的教学方法无法达到满意的教学效果。在教学方法的探索与实践中,采用抛砖引玉引导学习法、案例教学法、情景教学法、先成果后教学法等多种教学方法,引发学生的学习兴趣,培养学生的模仿和创新能力。同时,采用分阶段教学方法,使学生更好地掌握该软件,进一步提高教学质量。  相似文献   
94.
Strategy, networks and systems in the global translation services market   总被引:1,自引:0,他引:1  
The globalisation of markets has led to an increased demand for language translation services that support and enable communication between economic partners. For example, technical documents, software systems, business documents and web sites all need to be translated into multiple languages for individual national markets, and the information that they contain changes periodically. This paper sets out a theoretical framework that describes the architectures of business processes within and between separate firms that are used to support the delivery and management of services. This is done by coordinating the fit between externally generated problem complexity, from customers, and the internally generated complexity of different potential network configuration solutions. The theoretical framework is an architecture of how complexity is generated and managed at the different structural levels and across the different processual stages of an industry. A case study of thebigword, a major international translation services company, illustrates how the framework is applied in practice. The case study analyses the implementation of an electronic market platform which enables the coordination of the different stakeholders involved in the translation services market. These stakeholders include translators, translation services companies and their clients in a global business network.  相似文献   
95.
在网页设计课程教学中,运用案例教学+项目驱动模式,以项目驱动教学活动为主线,以案例教学任务为学习目标,可以充分发挥学生主体的学习积极性与教师的主导作用,取得良好的教学效果,提高学生的综合技能与就业能力。  相似文献   
96.
该文在动态二进制搜索算法的基础上提出了一种新的防碰撞算法,该算法充分利用已得到的冲突信息,有效减小判断过程中数据的传输量。通过对新算法的分析,可知本算法相对于动态二进制搜索算法有明显的优势。  相似文献   
97.
为在现场可编程门阵列(FPGA)中实现快速高精度除法,在传统的倒数除法的基础上,提出一种改进算法.对倒数求解采用泰勒级数展开结合优化搜索逼近,求出各个分区间内的拟合一次两项式,再通过一次牛顿迭代提高精度.时序仿真结果表明,以该算法构建的除法器易于在FPGA上实现,时延仅为6个时钟周期,能达到2(-34)的有效精度和86...  相似文献   
98.
Whenever there is any fault in an automotive engine ignition system or changes of an engine condition, an automotive mechanic can conventionally perform an analysis on the ignition pattern of the engine to examine symptoms, based on specific domain knowledge (domain features of an ignition pattern). In this paper, case-based reasoning (CBR) approach is presented to help solve human diagnosis problem using not only the domain features but also the extracted features of signals captured using a computer-linked automotive scope meter. CBR expert system has the advantage that it provides user with multiple possible diagnoses, instead of a single most probable diagnosis provided by traditional network-based classifiers such as multi-layer perceptions (MLP) and support vector machines (SVM). In addition, CBR overcomes the problem of incremental and decremental knowledge update as required by both MLP and SVM. Although CBR is effective, its application for high dimensional domains is inefficient because every instance in a case library must be compared during reasoning. To overcome this inefficiency, a combination of preprocessing methods, such as wavelet packet transforms (WPT), kernel principal component analysis (KPCA) and kernel K-means (KKM) is proposed. Considering the ignition signals captured by a scope meter are very similar, WPT is used for feature extraction so that the ignition signals can be compared with the extracted features. However, there exist many redundant points in the extracted features, which may degrade the diagnosis performance. Therefore, KPCA is employed to perform a dimension reduction. In addition, the number of cases in a case library can be controlled through clustering; KKM is adopted for this purpose. In this paper, several diagnosis methods are also used for comparison including MLP, SVM and CBR. Experimental results showed that CBR using WPT and KKM generated the highest accuracy and fitted better the requirements of the expert system.  相似文献   
99.
We introduce nondeterministic graph searching with a controlled amount of nondeterminism and show how this new tool can be used in algorithm design and combinatorial analysis applying to both pathwidth and treewidth. We prove equivalence between this game-theoretic approach and graph decompositions called q -branched tree decompositions, which can be interpreted as a parameterized version of tree decompositions. Path decomposition and (standard) tree decomposition are two extreme cases of q-branched tree decompositions. The equivalence between nondeterministic graph searching and q-branched tree decomposition enables us to design an exact (exponential time) algorithm computing q-branched treewidth for all q≥0, which is thus valid for both treewidth and pathwidth. This algorithm performs as fast as the best known exact algorithm for pathwidth. Conversely, this equivalence also enables us to design a lower bound on the amount of nondeterminism required to search a graph with the minimum number of searchers. Additional support of F.V. Fomin by the Research Council of Norway. Additional supports of P. Fraigniaud from the INRIA Project “Grand Large”, and from the Project PairAPair of the ACI “Masse de Données”. Additional supports of N. Nisse from the Project Fragile of the ACI “Sécurité & Informatique”.  相似文献   
100.
Fraigniaud et al. [L. Blin, P. Fraigniaud, N. Nisse, S. Vial, Distributing chasing of network intruders, in: 13th Colloquium on Structural Information and Communication Complexity, SIROCCO, in: LNCS, vol. 4056, Springer-Verlag, 2006, pp. 70–84] introduced a new measure of difficulty for a distributed task in a network. The smallest number of bits of advice   of a distributed problem is the smallest number of bits of information that has to be available to nodes in order to accomplish the task efficiently. Our paper deals with the number of bits of advice required to perform efficiently the graph searching problem in a distributed setting. In this variant of the problem, all searchers are initially placed at a particular node of the network. The aim of the team of searchers is to clear a contaminated graph in a monotone connected way, i.e., the cleared part of the graph is permanently connected, and never decreases while the search strategy is executed. Moreover, the clearing of the graph must be performed using the optimal number of searchers, i.e. the minimum number of searchers sufficient to clear the graph in a monotone connected way in a centralized setting. We show that the minimum number of bits of advice permitting the monotone connected and optimal clearing of a network in a distributed setting is Θ(nlogn)Θ(nlogn), where nn is the number of nodes of the network. More precisely, we first provide a labelling of the vertices of any graph GG, using a total of O(nlogn)O(nlogn) bits, and a protocol using this labelling that enables the optimal number of searchers to clear GG in a monotone connected distributed way. Then, we show that this number of bits of advice is optimal: any distributed protocol requires Ω(nlogn)Ω(nlogn) bits of advice to clear a network in a monotone connected way, using an optimal number of searchers.  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