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   3596篇
  免费   195篇
  国内免费   3篇
电工技术   55篇
综合类   2篇
化学工业   602篇
金属工艺   71篇
机械仪表   43篇
建筑科学   232篇
矿业工程   27篇
能源动力   88篇
轻工业   439篇
水利工程   27篇
石油天然气   17篇
无线电   309篇
一般工业技术   576篇
冶金工业   434篇
原子能技术   30篇
自动化技术   842篇
  2023年   36篇
  2022年   33篇
  2021年   104篇
  2020年   73篇
  2019年   105篇
  2018年   132篇
  2017年   118篇
  2016年   152篇
  2015年   113篇
  2014年   153篇
  2013年   245篇
  2012年   209篇
  2011年   238篇
  2010年   178篇
  2009年   175篇
  2008年   205篇
  2007年   181篇
  2006年   156篇
  2005年   127篇
  2004年   122篇
  2003年   89篇
  2002年   114篇
  2001年   44篇
  2000年   47篇
  1999年   44篇
  1998年   73篇
  1997年   55篇
  1996年   51篇
  1995年   34篇
  1994年   38篇
  1993年   33篇
  1992年   30篇
  1991年   24篇
  1990年   24篇
  1989年   25篇
  1988年   9篇
  1987年   19篇
  1986年   18篇
  1985年   20篇
  1984年   29篇
  1983年   14篇
  1982年   13篇
  1981年   11篇
  1980年   15篇
  1979年   12篇
  1977年   7篇
  1976年   10篇
  1975年   8篇
  1974年   6篇
  1973年   6篇
排序方式: 共有3794条查询结果,搜索用时 15 毫秒
101.
102.
Recently, there has been an increasing interest in directed probabilistic logical models and a variety of formalisms for describing such models has been proposed. Although many authors provide high-level arguments to show that in principle models in their formalism can be learned from data, most of the proposed learning algorithms have not yet been studied in detail. We introduce an algorithm, generalized ordering-search, to learn both structure and conditional probability distributions (CPDs) of directed probabilistic logical models. The algorithm is based on the ordering-search algorithm for Bayesian networks. We use relational probability trees as a representation for the CPDs. We present experiments on a genetics domain, blocks world domains and the Cora dataset. Editors: Stephen Muggleton, Ramon Otero, Simon Colton.  相似文献   
103.
利用视频套件加速FPGA上的视频开发   总被引:1,自引:0,他引:1  
处理器友好型视频开发的新方法,无须VHDL或Verilog知识即可生成高度优化的结果 随着下一代视频压缩标准问世,行业从基本视频处理向更复杂的集成处理解决方案转移,达使得系统的要求超越了独立DSP力所能及的视频性能.FPGA以不到30美元的价格提供20GMACs以上的DSP性能,从而为成本敏感型军事、汽车、医疗、消费、工业和安全应用填补了这一空白.只有FPGA能够为整套端对端视频解决方案提供逻辑、嵌入式处理、OS支持和驱动器.  相似文献   
104.
We understand regulatory policy problems against the backdrop of existing implementations of a regulatory framework. There are argument schemes for proposing a policy and for criticising a proposal, rooted in a shared understanding that there is an existing regulatory framework which is implemented in social structures in society, yet has problems. The problems with the existing implementations may be attributed either to those implementations or to the constraints imposed by the regulatory framework. In this paper we propose that calls for change of regulatory policy, and case-based and statistical evidence produced in support of policy proposals, are based in model-based problem solving activities. This perspective suggests schemes for a good argument pro or con a policy proposal, while avoiding the problem of backing up claims and evidence on the policy level with a conjectural deep model of the policy domain.  相似文献   
105.
The Citywide project is exploring ways in which technology can provide people with rich and engaging digital experiences as they move through physical space, including historical experiences, performances and games. This paper describes some initial results and experiences with this project based upon two prototype demonstrators. In the first, we describe an application in which a search party explores an archaeological site, uncovering enacted scenes within the virtual world that are of a historical relevance to their particular physical location. In the second, we describe a museum experience where participants explore an outdoors location, hunting for buried virtual artifacts that they then bring back to a museum for a more detailed study. Our demonstrators employ a varied set of devices, including mobile wireless interfaces for locating hotspots of virtual activity when outdoors, to give different experiences of the virtual world depending upon location, task, available equipment and accuracy of tracking. We conclude by discussing some of the potential advantages of using an underlying shared virtual world to support interactive experiences across extended physical settings.  相似文献   
106.
This paper provides an overview of various existing approaches to automated formal analysis and verification. The most space is devoted to the approach of model checking, including its basic principles as well as the different techniques that have been proposed for dealing with the state space explosion problem in model checking. This paper, however, includes a brief discussion of theorem proving and static analysis too. All of the discussed approaches are introduced mostly on an informal level, with an attempt to provide the reader with their basic ideas and references to works where more details can be found.  相似文献   
107.
With the rise in stereoscopic 3D media, there has been concern that viewing stereoscopic 3D (S3D) content could have long-term adverse effects, but little data are available. In the first study to address this, 28 households who did not currently own a 3D TV were given a new TV set, either S3D or 2D. The 116 members of these households all underwent tests of balance, coordination and eyesight, both before they received their new TV set, and after they had owned it for 2 months. We did not detect any changes which appeared to be associated with viewing 3D TV. We conclude that viewing 3D TV does not produce detectable effects on balance, coordination or eyesight over the timescale studied.

Practitioner Summary: Concern has been expressed over possible long-term effects of stereoscopic 3D (S3D). We looked for any changes in vision, balance and coordination associated with normal home S3D TV viewing in the 2 months after first acquiring a 3D TV. We find no evidence of any changes over this timescale.  相似文献   

108.
109.
Whole exome sequencing of invasive mammary carcinomas revealed the association of mutations in PTEN and ZFHX3 tumor suppressor genes (TSGs). We generated single and combined PTEN and ZFHX3 knock-outs (KOs) in the immortalized mammary epithelial cell line MCF10A to study the role of these genes and their potential synergy in migration regulation. Inactivation of PTEN, but not ZFHX3, induced the formation of large colonies in soft agar. ZFHX3 inactivation in PTEN KO, however, increased colony numbers and normalized their size. Cell migration was affected in different ways upon PTEN and ZFHX3 KO. Inactivation of PTEN enhanced coordinated cell motility and thus, the collective migration of epithelial islets and wound healing. In contrast, ZFHX3 knockout resulted in the acquisition of uncoordinated cell movement associated with the appearance of immature adhesive junctions (AJs) and the increased expression of the mesenchymal marker vimentin. Inactivation of the two TSGs thus induces different stages of partial epithelial-to-mesenchymal transitions (EMT). Upon double KO (DKO), cells displayed still another motile state, characterized by a decreased coordination in collective migration and high levels of vimentin but a restoration of mature linear AJs. This study illustrates the plasticity of migration modes of mammary cells transformed by a combination of cancer-associated genes.  相似文献   
110.
During the past two decades, landscape has frequently been conceptualized as a distancing way of seeing space. This conceptualization is normally traced back to the rise of capitalism and various modes of artistic representation, notably in the early modern Netherlands or the northern Low Countries. Yet recent scholarly interventions have asserted that landscape in the Low Countries and elsewhere in Europe was more than a distant scenery or an artistic mode of representation. Landscape also animated practices and ideologies of political representation, platial justice and custom. The platial notion of landscape and related concepts in the northern Low Countries around 1600 is focused upon, bringing out the intimate relationships between land, water and diverging ideals and practices of justice. It is argued that artistic landscape representation provided ways to reflect upon spatio-political developments in the Netherlands. Finally, there is a brief consideration of how these theoretical and historical issues resonate with modern thinking about landscape in physical planning.  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