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   1641980篇
  免费   33758篇
  国内免费   9654篇
工业技术   1685392篇
  2021年   17199篇
  2020年   13858篇
  2019年   16405篇
  2018年   19580篇
  2017年   19304篇
  2016年   24380篇
  2015年   20093篇
  2014年   31942篇
  2013年   91822篇
  2012年   42697篇
  2011年   57393篇
  2010年   48546篇
  2009年   56112篇
  2008年   52058篇
  2007年   49814篇
  2006年   50684篇
  2005年   45261篇
  2004年   46180篇
  2003年   45581篇
  2002年   41776篇
  2001年   38757篇
  2000年   36245篇
  1999年   36841篇
  1998年   60381篇
  1997年   48161篇
  1996年   40472篇
  1995年   35004篇
  1994年   32337篇
  1993年   31738篇
  1992年   27017篇
  1991年   24372篇
  1990年   24500篇
  1989年   23410篇
  1988年   21958篇
  1987年   20110篇
  1986年   19697篇
  1985年   22991篇
  1984年   22740篇
  1983年   20559篇
  1982年   19382篇
  1981年   19507篇
  1980年   18178篇
  1979年   18660篇
  1978年   17895篇
  1977年   18540篇
  1976年   21036篇
  1975年   16060篇
  1974年   15562篇
  1973年   15685篇
  1972年   13189篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
991.
Metallurgical and Materials Transactions B - The effect of the surface tension–viscosity dissipation driving liquid Ti flow into a B4C packed bed was analyzed at 1941 K and 2573 K. The model...  相似文献   
992.
Metallurgical and Materials Transactions B - Because of interfacial and surface tension, micron-sized liquid oxide droplets are expected to change from spherical (when fully immersed in liquid...  相似文献   
993.
994.
Past social TV (STV) system user studies usually tested a small number of trialists in lab settings in Western countries. This Asian research took a mix method approach (interview, observation, and web survey) to examine the attitudes of 76 young adults’ experiences of using a multiscreen STV system. The results show that the majority of participants preferred shifting and complementary patterns when using STV. Their favorite feature was multiscreen video teleportation via QR codes. Nearly half of participants agreed that sociability features of the STV system could facilitate their perceived social presence and sense of community, which increased adoption intention. Additionally, text messaging was selected as the preferred mode for social interactions during video viewing. Although most participants liked the user-friendly design to upload and share videos conveniently, age has a negative association with users’ receptiveness of the user generated video channel creation and aggregation feature.  相似文献   
995.
Differential graphical games have been introduced in the literature to solve state synchronization problem for linear homogeneous agents. When the agents are heterogeneous, the previous notion of graphical games cannot be used anymore and a new definition is required. In this paper, we define a novel concept of differential graphical games for linear heterogeneous agents subject to external unmodeled disturbances, which contain the previously introduced graphical game for homogeneous agents as a special case. Using our new formulation, we can solve both the output regulation and H output regulation problems. Our graphical game framework yields coupled Hamilton‐Jacobi‐Bellman equations, which are, in general, impossible to solve analytically. Therefore, we propose a new actor‐critic algorithm to solve these coupled equations numerically in real time. Moreover, we find an explicit upper bound for the overall ‐gain of the output synchronization error with respect to disturbance. We demonstrate our developments by a simulation example.  相似文献   
996.
Journal of Computer and Systems Sciences International - The effect of a significant and sudden loss of the greatest possible average traction during a vehicle’s intense acceleration is found...  相似文献   
997.
Journal of Computer and Systems Sciences International - The model for the representation of declarative and procedural knowledge of an autonomous intelligent robot is developed without reference...  相似文献   
998.
Journal of Computer and Systems Sciences International - A method for searching for an optimal law of control over a limited resource source is proposed. Among the examples of sources from the...  相似文献   
999.
Journal of Computer and Systems Sciences International - The technology for the visual inspection of aircraft surfaces using programmable unmanned aerial vehicles (drones) is presented. When...  相似文献   
1000.
Journal of Computer and Systems Sciences International - It is shown that if a robot’s body has an upper shell in the shape of a truncated cylinder, then a six-legged insectomorphic robot can...  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-23

京公网安备 11010802026262号