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   179164篇
  免费   7851篇
  国内免费   163篇
  187178篇
  2021年   1534篇
  2020年   2813篇
  2019年   3475篇
  2018年   3672篇
  2017年   4106篇
  2016年   4739篇
  2015年   3952篇
  2014年   4843篇
  2013年   23729篇
  2012年   4956篇
  2011年   4029篇
  2010年   4079篇
  2009年   4876篇
  2008年   4228篇
  2007年   3849篇
  2006年   4348篇
  2005年   4279篇
  2004年   3753篇
  2003年   3416篇
  2002年   3208篇
  2001年   3413篇
  2000年   3250篇
  1999年   3274篇
  1998年   2840篇
  1997年   2696篇
  1996年   2596篇
  1995年   2456篇
  1994年   2404篇
  1993年   2359篇
  1992年   2712篇
  1991年   2508篇
  1990年   2398篇
  1989年   2275篇
  1988年   2281篇
  1987年   2291篇
  1986年   2250篇
  1985年   2439篇
  1984年   2558篇
  1983年   2362篇
  1982年   2398篇
  1981年   2361篇
  1980年   2220篇
  1979年   2294篇
  1978年   2229篇
  1977年   2181篇
  1976年   2000篇
  1975年   2055篇
  1974年   2114篇
  1973年   2008篇
  1972年   1543篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
OBJECTIVE: This report reviews the evidence that informs the role of health and mental health care providers in addressing youth smoking cessation. DESIGN: Qualitative literature review. RESULTS: Physicians do not consistently screen adolescents for tobacco use and fail to provide recommended cessation advice. Challenges to addressing smoking cessation include the need for procedures to ensure confidentiality and the existence of competing demands to provide other services. Few published studies have specifically addressed the effectiveness of clinical interventions. Interventions that require return visits or follow-up phone contacts are technically difficult to implement in this population. Successful interventions may require resources not available in nonresearch settings. Most studies have used brief clinical intervention as a control condition, making it impossible to evaluate its effectiveness. CONCLUSION: There is little evidence that supports current clinical smoking cessation guidelines for adolescents. More research is needed to develop inexpensive, efficient clinical interventions that can provide youths access to smoking cessation help. Future challenges include reorganizing clinical systems to offer greater counseling by support staff or in electronic formats and to provide effective booster messages and follow-up care in a population that is difficult to track.  相似文献   
132.
133.
An electronic apparatus using infrared beams for monitoring the movements of individual bees under dark conditions is described. The searching behavior of workers in an arena was monitored over 2-h periods. Mean ambulatory velocity for one bee over a distance of 100 mm was 45.6±1.51 mm/sec (n=45). Thigmokinesis and temporal activity patterns are illustrated.  相似文献   
134.
135.
136.
137.
陈莲笙道长生于1917年10月25日,上海市人.历任中国道教协会副会长,中国道教协会顾问,上海市道教协会会长.上海市道教协会名誉会长,上海城隍庙住持,上海道学院院长,<上海道教>杂志主编,上海市宗教学会理事,上海市政协第七届委员,上海市政协第八、九届常委等职.  相似文献   
138.
This study addresses the demands of alternating bimanual syncopation, a coordination mode in which the two hands move in alternation while tapping in antiphase with a metronomic tone sequence. Musically trained participants were required to engage in alternating bimanual syncopation and five other coordination modes: unimanual syncopation where taps are made (with the left or right hand) after every tone; unimanual syncopation where taps are made after every other tone; bimanual synchronization with alternating hands; unimanual synchronized tapping with every tone; and unimanual tapping with every other tone. Variability in tap timing was greatest overall for alternating bimanual syncopation, indicating that it is the most difficult. This appears to be due to instability arising from the simultaneous presence of two levels of antiphase coordination (one between the pacing sequence and the hands, the other between the two hands) rather than factors relating to movement frequency or dexterity limits of the nonpreferred hand.  相似文献   
139.
This essay will focus on the Buddhist metaphysics of experience which is generally glossed over due to the excessive concern for the ultimate goal in Buddhism, nirvīna , and in consequence of which the emphasis has been on the practice of; meditative discipline in aspiration for that goal. Yet neither nirvana nor meditative discipline can be understood properly without examining the full dimension of our ordinary experience. Such an examination should reveal to us the unique ways in which the Buddhist refers to the bounded and unbounded conditions of existence. All this is novel insofar as metaphysics goes and indeed it would have to be a unique form of metaphysics in order to accommodate the dual aspect of existence. The key to this metaphysics lodges in the Buddhist concept of experiential process,1 technically known as pratītyasamutpāda which is variously translated as relational origination, interrelational origination or dependent origination. It refers to the Buddhist concept of causality but, as we shall see, it is a unique concept with more than the usual Western connotation.  相似文献   
140.
The current study was designed to gain a better understanding of the nature of the relationship between substance use and sexual risk taking within a community sample of women (N = 1,004). Using confirmatory factor analysis, the authors examined the factor structure of sexual risk behaviors and substance use to determine whether they are best conceptualized as domains underlying a single, higher order, risk-taking propensity. A 2 higher order factor model (sexual risk behavior and substance use) provided the best fit to the data, suggesting that these 2 general risk domains are correlated but independent factors. Sensation seeking had large general direct effects on the 2 risk domains and large indirect effects on the 4 first-order factors and the individual indicators. Negative affect had smaller, yet still significant, effects. Impulsivity and anxiety were unrelated to sexual health risk domains.  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