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   187722篇
  免费   8343篇
  国内免费   155篇
  2020年   2776篇
  2019年   3440篇
  2018年   3655篇
  2017年   4096篇
  2016年   4699篇
  2015年   3927篇
  2014年   4802篇
  2013年   23428篇
  2012年   4965篇
  2011年   4271篇
  2010年   4084篇
  2009年   4851篇
  2008年   4402篇
  2007年   4029篇
  2006年   4480篇
  2005年   4382篇
  2004年   3867篇
  2003年   3461篇
  2002年   3320篇
  2001年   4041篇
  2000年   3906篇
  1999年   3653篇
  1998年   2888篇
  1997年   2724篇
  1996年   2639篇
  1995年   2451篇
  1994年   2414篇
  1993年   2386篇
  1992年   3037篇
  1991年   2843篇
  1990年   2687篇
  1989年   2546篇
  1988年   2535篇
  1987年   2522篇
  1986年   2558篇
  1985年   2754篇
  1984年   2749篇
  1983年   2496篇
  1982年   2444篇
  1981年   2416篇
  1980年   2245篇
  1979年   2526篇
  1978年   2327篇
  1977年   2244篇
  1976年   2049篇
  1975年   2234篇
  1974年   2314篇
  1973年   2245篇
  1972年   1830篇
  1971年   1724篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
We investigated motivational and cognitive processes of behavior change with respect to mammography screening. One hundred forty-two women (ages 40 and older) recruited from three worksites answered a 41-item questionnaire consisting of statements based on constructs from the transtheoretical model of behavior change. Principal-components analysis identified two factors: a six-item component representing positive perceptions of mammography (Pros) and a six-item component representing avoidance of mammography (Cons). Analysis of variance showed that Pros, Cons, and a derived Decisional Balance measure (Pros minus Cons) were associated with stage of mammography adoption. Results are consistent with applications of the model to smoking cessation. The model is also discussed as it relates to other theories of behavior change and as a general strategy for analyzing perceptual data pertinent to health-related actions and intentions for behavioral change.  相似文献   
54.
Range of electric vehicles (EVs) has long been considered a major barrier in acceptance of electric mobility. We examined the nature of how range is experienced in an EV and whether variables from other adaptation contexts, notably stress, have explanatory power for inter‐individual differences in what we term comfortable range. Forty EVs were leased to a sample of users for a 6‐month field study. Qualitative and quantitative analyses of range experiences were performed, including regression analyses to examine the role of stress‐buffering personality traits and coping skills in comfortable range. Users appraised range as a resource to which they could successfully adapt and that satisfied most of their daily mobility needs. However, indicators were found that suggested suboptimal range utilisation. Stress‐buffering personality traits (control beliefs, ambiguity tolerance) and coping skills (subjective range competence, daily range practice) were found to play a substantial role in comfortable range. Hence, it may be possible to overcome perceived range barriers with the assistance of psychological interventions such as information, training, and interface design. Providing drivers with a reliable usable range may be more important than enhancing maximal range in an electric mobility system.  相似文献   
55.
56.
57.
58.
59.
60.
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