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   2004篇
  免费   459篇
  国内免费   420篇
电工技术   37篇
综合类   229篇
化学工业   18篇
金属工艺   15篇
机械仪表   197篇
建筑科学   44篇
矿业工程   12篇
能源动力   3篇
轻工业   13篇
水利工程   3篇
武器工业   16篇
无线电   144篇
一般工业技术   65篇
冶金工业   24篇
原子能技术   2篇
自动化技术   2061篇
  2023年   15篇
  2022年   24篇
  2021年   28篇
  2020年   55篇
  2019年   42篇
  2018年   40篇
  2017年   45篇
  2016年   69篇
  2015年   113篇
  2014年   147篇
  2013年   165篇
  2012年   228篇
  2011年   257篇
  2010年   299篇
  2009年   287篇
  2008年   302篇
  2007年   275篇
  2006年   174篇
  2005年   122篇
  2004年   79篇
  2003年   46篇
  2002年   20篇
  2001年   13篇
  2000年   13篇
  1999年   4篇
  1998年   2篇
  1997年   2篇
  1996年   4篇
  1995年   4篇
  1994年   3篇
  1993年   2篇
  1990年   2篇
  1988年   1篇
  1987年   1篇
排序方式: 共有2883条查询结果,搜索用时 15 毫秒
1.
Computer‐Interpretable Guidelines (CIGs) are the dominant medium for the delivery of clinical decision support, given the evidence‐based nature of their source material. Therefore, these machine‐readable versions have the ability to improve practitioner performance and conformance to standards, with availability at the point and time of care. The formalisation of Clinical Practice Guideline knowledge in a machine‐readable format is a crucial task to make it suitable for the integration in Clinical Decision Support Systems. However, the current tools for this purpose reveal shortcomings with respect to their ease of use and the support offered during CIG acquisition and editing. In this work, we characterise the current landscape of CIG acquisition tools based on the properties of guideline visualisation, organisation, simplicity, automation, manipulation of knowledge elements, and guideline storage and dissemination. Additionally, we describe the CompGuide Editor, a tool for the acquisition of CIGs in the CompGuide model for Clinical Practice Guidelines that also allows the editing of previously encoded guidelines. The Editor guides the users throughout the process of guideline encoding and does not require proficiency in any programming language. The features of the CIG encoding process are revealed through a comparison with already established tools for CIG acquisition.  相似文献   
2.
3.
4.
Our primary research hypothesis stands on a simple idea: The evolution of top-rated publications on a particular theme depends heavily on the progress and maturity of related topics. And this even when there are no clear relations or some concepts appear to cease to exist and leave place for newer ones starting many years ago. We implemented our model based on Computer Science Ontology (CSO) and analyzed 44 years of publications. Then we derived the most important concepts related to Cloud Computing (CC) from the scientific collection offered by Clarivate Analytics. Our methodology includes data extraction using advanced web crawling techniques, data preparation, statistical data analysis, and graphical representations. We obtained related concepts after aggregating the scores using the Jaccard coefficient and CSO Ontology. Our article reveals the contribution of Cloud Computing topics in research papers in leading scientific journals and the relationships between the field of Cloud Computing and the interdependent subdivisions identified in the broader framework of Computer Science.  相似文献   
5.
ABSTRACT

Many planning agencies worldwide now see climate change response as unavoidable. This paper proposes that a central task for contemporary planning theory is to guide planning practice as it develops multi-dimensional responses. We examine three theoretical constructs: anticipatory governance, legitimacy and social-ecological resilience. We argue that each conceptualises challenges climate change presents to planning practice, while providing theoretically informed options for responses. Building on this, we utilize Friedmann’s [2008. “The Uses of Planning Theory: A Bibliographic Essay.” Journal of Planning Education and Research 28 (2): 247–257. doi:10.1177/0739456X08325220] tasks for planning theory as a framework to assess the utility of planning theories to guide climate change response through practice. Associated issues are discussed, including the influence of translatable planning theories and the value of importing knowledge from other disciplines. The paper concludes that more sophisticated interplay between planning theory and practice may improve planning responses to the climate change threat. The need for planning theory to translate its conceptual discoveries to the domain of practice is key.  相似文献   
6.
通过对中国图书馆分类法和中国科学院图书馆图书分类法及测绘学叙词表等相关资料的分析,确定本体中的类和定义类的语义关系,基于Protégé工具构建测绘学科信息公共本体、测绘学科分类—中图法本体及测绘学科分类—科图法本体,在构建的本体基础上基于Oracle 11g语义技术构建测绘学科分类本体库,为进一步语义检索提供基础.  相似文献   
7.
在分析改模知识的基础上,提出了一种基于本体的聚类分析法来获得典型的改模方案,建立了注塑模改模知识领域本体,确立了用矩阵方法表达改模方案数据的数学模型。通过基于改模知识领域本体之间概念相似度的计算获得改模概念间的语义相似度、用归一化公式计算改模方案间的相似度和簇间相似度,用相似度矩阵表示改模方案间的相似度,并应用凝聚的层次聚类法进行改模方案的聚类,通过改模方案聚类粒度的确定方法获得聚类结果。以企业的改模方案数据为例,验证了该方法的有效性。  相似文献   
8.
基于本体和云模型的电能质量信息状态监测平台   总被引:1,自引:0,他引:1       下载免费PDF全文
提出了一种适用于智能电网的电能质量信息状态监测平台。将本体技术引入到该平台建设中,建立了电能质量信息状态监测领域的领域本体,借助该领域本体可以实现电能质量信息的快速检索。建立的电能质量信息状态监测检索引擎可以在领域本体的指导下从电能质量数据库中提取出符合条件的数据集合,再将定制处理后的检索结果返回给用户。平台引入了云模型技术,基于云模型完成对电能质量信息的诊断,以实现电能质量信息的状态诊断和实时监测。实例展示介绍了平台的操作界面和具体实现界面,可见该平台具有一定的工程实用价值。  相似文献   
9.
Numerous studies have demonstrated that genes, RNAs, and proteins are involved in the occurrence and development of stroke. In addition, previous studies concluded that microRNAs (miRNAs or miRs) are closely related to the pathological process of ischemic and hypoxic disease. Therefore, the aims of this study were to quantify the altered expression levels of miRNAs in the infarct region 6 h after middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia in mice using a large-scale miRNAs microarray. Firstly, MCAO-induced cerebral ischemic injuries were investigated by observing the changes of neurological deficits, infarct volume and edema ratio. One hundred and eighteen differentially expressed miRNAs were identified in the infarct region of mice following the MCAOs compared with sham group (p < 0.05 was considered as significant). Among these 118 significantly expressed microRNAs, we found that 12 miRNAs were up-regulated with fold changes lager than two, and 18 miRNAs were down-regulated with fold changes less than 0.5 in the infarct region of mice following the 6 h MCAOs, compared with the sham group. Then, these 30 miRNAs with expression in fold change larger than two or less than 0.5 was predicted, and the functions of the target genes of 30 miRNAs were analyzed using a bioinformatics method. Finally, the miRNA-gene network was established and the functional miRNA-mRNA pairs were identified, which provided insight into the roles of the specific miRNAs that regulated specified genes in the ischemic injuries. The miRNAs identified in this study may represent effective therapeutic targets for stroke, and further study of the role of these targets may increase our understanding of the mechanisms underlying ischemic injuries.  相似文献   
10.
冉婕  漆丽娟 《电子设计工程》2015,23(5):12-14,17
基于语义检索的目的,结合成语典故本体的构建,设计了一个基于成语典故本体的语义检索模型,阐述了检索模型中用户界面模块、数据存储模块、查询分析模块和检索分析模块的功能;分析了系统中的本体构建技术、分词技术及检索技术,设计并实现了词语相似度及概念相似度算法;通过语义检索系统的实验,得到较高的查全率和查准率.  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