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   17344篇
  免费   1959篇
  国内免费   1440篇
电工技术   1673篇
技术理论   7篇
综合类   1846篇
化学工业   929篇
金属工艺   304篇
机械仪表   1666篇
建筑科学   1655篇
矿业工程   465篇
能源动力   514篇
轻工业   410篇
水利工程   318篇
石油天然气   440篇
武器工业   166篇
无线电   2068篇
一般工业技术   1569篇
冶金工业   522篇
原子能技术   58篇
自动化技术   6133篇
  2024年   91篇
  2023年   264篇
  2022年   480篇
  2021年   643篇
  2020年   624篇
  2019年   485篇
  2018年   430篇
  2017年   521篇
  2016年   598篇
  2015年   769篇
  2014年   1280篇
  2013年   1136篇
  2012年   1310篇
  2011年   1515篇
  2010年   1227篇
  2009年   1077篇
  2008年   1086篇
  2007年   1207篇
  2006年   1073篇
  2005年   963篇
  2004年   828篇
  2003年   669篇
  2002年   472篇
  2001年   453篇
  2000年   329篇
  1999年   258篇
  1998年   188篇
  1997年   166篇
  1996年   124篇
  1995年   106篇
  1994年   71篇
  1993年   67篇
  1992年   50篇
  1991年   33篇
  1990年   31篇
  1989年   21篇
  1988年   27篇
  1987年   8篇
  1986年   12篇
  1985年   8篇
  1984年   8篇
  1983年   7篇
  1982年   2篇
  1981年   3篇
  1980年   4篇
  1979年   2篇
  1975年   2篇
  1964年   3篇
  1956年   2篇
  1955年   1篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
According to Carl Jung, a person's symptoms occur as a result of the psyche's creative attempt to self-regulate. These symptoms are viewed as the symbol-making function of the psyche. Music therapy as a therapeutic tool is also viewed as having a symbol-making function in that the physical act of making music involves conceptualizing one's symptoms into sounds. The sound serves as a musical symbol of the symptom. The myth of Orpheus is offered as an example of how early man amplified the creative potential contained in music to heal from life's woes. The Orphic archetype illustrates that music serves as a medium for healing and as an expression of Self. That psyche can be healed by music is a reminder of the connection between music therapy and the myth of Orpheus. In using the therapeutic tool of music one can transcend, through the symbol making process inherent in music therapy, the tension of opposites that are created at the crossroads of disease and wellness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
32.
33.
Applications of the discrete element method in mechanical engineering   总被引:2,自引:0,他引:2  
Compared to other fields of engineering, in mechanical engineering, the Discrete Element Method (DEM) is not yet a well known method. Nevertheless, there is a variety of simulation problems where the method has obvious advantages due to its meshless nature. For problems where several free bodies can collide and break after having been largely deformed, the DEM is the method of choice. Neighborhood search and collision detection between bodies as well as the separation of large solids into smaller particles are naturally incorporated in the method. The main DEM algorithm consists of a relatively simple loop that basically contains the three substeps contact detection, force computation and integration. However, there exists a large variety of different algorithms to choose the substeps to compose the optimal method for a given problem. In this contribution, we describe the dynamics of particle systems together with appropriate numerical integration schemes and give an overview over different types of particle interactions that can be composed to adapt the method to fit to a given simulation problem. Surface triangulations are used to model complicated, non-convex bodies in contact with particle systems. The capabilities of the method are finally demonstrated by means of application examples. Commemorative Contribution.  相似文献   
34.
Local Exact Particle Tracing on Unstructured Grids   总被引:1,自引:0,他引:1  
For analyzing and interpreting results of flow simulations, particle tracing is a well established visualization method. In addition, it is a preliminary step for more advanced techniques such as line integral convolution. For interactive exploration of large data sets, a very efficient and reliable particle tracing method is needed. For wind channel experiments or flight simulations, large unstructured computational grids have become common practice. Traditional approachs, based on numerical integration methods of ordinary differential equations however fail to deliver sufficiently accurate path calculation at the speed required for interactive use. In this paper we extend the local exact approach of Nielson and Jung in such a way that it can be used for interactive particle tracing in large data sets of steady flow simulation experiments. This will be achieved by sophisticated preprocessing using additional memory. For further visual enhancement of the streamline we construct an implicitly defined smooth Bézier curve that is used for ray tracing. This allows us to visualize additional scalar values of the simulation as attributes to the trajectory and enables the display of high‐quality smooth curves without creating any visualization geometry and providing a good impression of the spatial situation at the same time. ACM CSS: I.3.3 Computer Graphics—Line and curve generation; I .3.7 Computer Graphics—Raytracing; G.1.2 Numerical Analysis—Spline and piecewise polynomial approximation  相似文献   
35.
Boundary objects are a critical, but understudied, theoretical construct in CSCW. Through a field study of aircraft technical support, we examined the role of boundary objects in the practical achievement of safety by service engineers. Their resolution of repair requests was preserved in the organization’s memory via three compound boundary objects. These crystallizations did not manifest a static interpretation, but instead were continually reinterpreted in light of meta-negotiations. This suggests design implications for organizational memory systems which can more fluidly represent the meta-negotiations surrounding boundary objects.  相似文献   
36.
Four experiments were conducted to investigate the relationship between the binding of visual features (as measured by their aftereffects on subsequent binding) and the learning of feature-conjunction probabilities. Both binding and learning effects were obtained, but they did not interact. Interestingly, (shape-color) binding effects disappeared with increasing practice, presumably because of the fact that only 1 of the features involved was relevant to the task. However, this instability was only observed for arbitrary, not highly overlearned combinations of simple geometric features and not for real objects (colored pictures of a banana and strawberry), where binding effects were strong and resistant to practice. These findings suggest that learning has no direct impact on the strength or resistance of bindings or on speed with which features are bound; however, learning does affect the amount of attention particular feature dimensions attract, which again can influence which features are considered in binding. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
37.
企业柔性:基于集成的观点   总被引:3,自引:0,他引:3  
从集成的思想出发分析了柔性的内涵,认为企业柔性的目标是提高企业在动态环境条件下的整体竞争优势,柔性的基础是在更大范围内的协调优化与有效集成;从系统的角度将企业柔性分为市场柔性,研发柔性,制造柔性与组织柔性四个维度,对每个维度所包括的具体内容进行了分析;建立了企业柔性的概念模型,从整体的角度出发对企业的柔性的形式与作用机制进行了描述。  相似文献   
38.
模式集成多数据库系统中需要解决的关键问题之一,己存在的大多数面向多数据库系统都采用了面向对象视图机制来建立集成模式。为了满足基于CORBA的CIMS信息集成平台呆订成的需要,本文提出了一种基于数据库管理组ODMG的ODMG-93标准的视图集成机制并通过一个完整的例子说明了这种视图机制在模式集成中的应用。  相似文献   
39.
中国民航信息系统现状及发展展望   总被引:2,自引:0,他引:2  
彭明田 《计算机工程》2005,31(Z1):61-63
介绍了中国民航信息系统的现状和与实际业务需求的差距,接着从系统设计理念、核心系统、新系统新功能和信息系统整合等多个方面详细阐述了民航信息系统的发展思路,最后强调了建立新一代民航信息系统的紧迫性,具备很强的指导意义。  相似文献   
40.
应用型机械本科专业教学体系改革研究与实践   总被引:4,自引:0,他引:4  
刘全良  顾平灿 《机电工程》2005,22(12):64-68
根据当前高等教育改革与发展的指导思想,紧紧围绕国家实施制造业信息化建设工程为背景,积极配合打造浙江先进制造业基地建设,结合现代机械专业结构调整,本着交叉、复合、应用型人才的培养目标,塑造具有宽口径、厚基础和强创新意识的人才培养理念,以数字化设计制造为核心,以机械技术、电子技术、信息技术和管理学科结合为主线,突出知识综合与创新能力,强调专业实践与专业知识的有效结合,有的放矢实施机械专业教学改革与实践。  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