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   131267篇
  免费   3499篇
  国内免费   566篇
工业技术   135332篇
  2024年   52篇
  2023年   584篇
  2022年   909篇
  2021年   1521篇
  2020年   1106篇
  2019年   1222篇
  2018年   15477篇
  2017年   14432篇
  2016年   11420篇
  2015年   1901篇
  2014年   2351篇
  2013年   3273篇
  2012年   6324篇
  2011年   12946篇
  2010年   10765篇
  2009年   8311篇
  2008年   9320篇
  2007年   9713篇
  2006年   2191篇
  2005年   2911篇
  2004年   2674篇
  2003年   2643篇
  2002年   1868篇
  2001年   1247篇
  2000年   1193篇
  1999年   999篇
  1998年   1644篇
  1997年   1035篇
  1996年   874篇
  1995年   580篇
  1994年   477篇
  1993年   420篇
  1992年   310篇
  1991年   304篇
  1990年   267篇
  1989年   252篇
  1988年   220篇
  1987年   174篇
  1986年   125篇
  1985年   119篇
  1984年   97篇
  1983年   70篇
  1982年   46篇
  1981年   47篇
  1976年   64篇
  1968年   47篇
  1966年   45篇
  1965年   46篇
  1955年   63篇
  1954年   68篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
6.
Mobile software applications have to cope with a particular environment that involves small size, limited resources, high autonomy requirements, competitive business models and many other challenges. To provide development guidelines that respond to these needs, several practices have been introduced; however, it is not clear how these guidelines may contribute to solve the issues present in the mobile domain. Furthermore, the rapid evolution of the mobile ecosystem challenges many of the premises upon which the proposed practices were designed. In this paper, we present a survey of the literature on software assurance practices for mobile applications, with the objective of describing them and assessing their contribution and success. We identified, organized and reviewed a body of research that spans in three levels: software development processes, software product assurance practices, and software implementation practices. By carrying out this literature survey, we reviewed the different approaches that researchers on Software Engineering have provided to address the needs that raise in the mobile software development arena. Moreover, we review the evolution of these practices, identifying how the constant changes and modernization of the mobile execution environment has impacted the methods proposed in the literature. Finally, we introduced discussion on the application of these practices in a real productive setting, opening an area for further research that may determine if practitioners have followed the proposed assurance paradigms.  相似文献   
7.
A technology for slag formation in the ladle–furnace unit is considered; the slag is based on the CaO–SiO2–MgO–Al2O3–B2O3 system. This technology permits both microalloying of the steel with boron (reduced from the oxide phase) and desulfurization of the steel. The resulting boron content in the steel is 0.001–0.008%; the sulfur content in low-alloy steel and pipe steel is low (0.004–0.010%); and the consumption of manganese ferroalloys is reduced to 0.5 kg/t for 08кп steel and 1.4 kg/t for 09Г2C steel. In addition, the proposed technology increases the strength of the rolled steel, without loss in its plasticity; and reduces the environmental impact thanks to the replacement of fluorspar by colemanite.  相似文献   
8.
9.
Variations of Incomplete Open Cubes is the major project by the twentieth-century conceptual artist Sol LeWitt. In this paper we interpret the enumerative component of the project as embeddings of graphs. This formulation permits use of an algorithm to check the completeness of the list of the structures produced by the artist. Our conclusion is that the artist found the correct number of structures (that is, 122), but that his list contains a mistake in the presentation of a pair of incomplete cubes, a discovery that appears not to have been noted before.  相似文献   
10.
Peer-to-Peer Networking and Applications - Recently, as the P2P service environment repeats evolution, its usage in mobile is rapidly increasing. Applications are being developed in various mobile...  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