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   156351篇
  免费   6462篇
  国内免费   3227篇
电工技术   4768篇
技术理论   6篇
综合类   6687篇
化学工业   23929篇
金属工艺   8733篇
机械仪表   7806篇
建筑科学   7422篇
矿业工程   2995篇
能源动力   3351篇
轻工业   8312篇
水利工程   2284篇
石油天然气   5664篇
武器工业   472篇
无线电   16804篇
一般工业技术   25424篇
冶金工业   6539篇
原子能技术   1029篇
自动化技术   33815篇
  2024年   316篇
  2023年   1296篇
  2022年   2169篇
  2021年   2987篇
  2020年   2252篇
  2019年   2015篇
  2018年   16360篇
  2017年   15594篇
  2016年   11843篇
  2015年   3364篇
  2014年   3717篇
  2013年   4459篇
  2012年   7505篇
  2011年   14114篇
  2010年   12387篇
  2009年   9425篇
  2008年   10549篇
  2007年   11411篇
  2006年   3948篇
  2005年   4658篇
  2004年   3413篇
  2003年   3261篇
  2002年   2407篇
  2001年   1746篇
  2000年   1991篇
  1999年   2122篇
  1998年   1833篇
  1997年   1461篇
  1996年   1461篇
  1995年   1208篇
  1994年   980篇
  1993年   727篇
  1992年   562篇
  1991年   452篇
  1990年   329篇
  1989年   255篇
  1988年   235篇
  1987年   142篇
  1986年   120篇
  1985年   97篇
  1984年   66篇
  1983年   40篇
  1982年   42篇
  1968年   46篇
  1966年   42篇
  1965年   45篇
  1958年   37篇
  1957年   36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.
7.
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   
8.
9.
10.
This study evaluated several physical and sensory parameters of different types of cheese available in the Polish market. The measurements of textural properties were conducted in an Instron universal testing machine, while the colour properties of cheeses were measured using a Minolta chromameter. The chemical composition was determined by means of the near‐infrared spectroscopy (NIRs). Moreover, a trained sensory panel was invited to assess the cheese texture‐related properties. Generally, cheeses with reduced fat content were characterised by higher hardness, adhesiveness, cohesiveness and elasticity. Texture‐related parameters of cheese with canola oil were comparable to that of most of full‐fat cheeses. The correlation analysis between physical and sensory attributes related to cheese textural properties indicated the potential applications of TPA, shear and penetration tests (= 0.766, = 0.75 and = 0.765, respectively) for the evaluation of sensory properties related to the hardness. Meanwhile, the elasticity of cheese obtained from sensory evaluation was strongly correlated with the elasticity determined from the shear test (= 0.722) and moderately correlated with the elasticity from penetration test (= 0.588), indicating a need to refine the method of penetration test. In addition, cheeses exhibited higher meltability during convection heating at 230 °C than microwave heating. The values of meltability for cheese with reduced fat content were lower than those of full‐fat cheese.  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