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   169482篇
  免费   7686篇
  国内免费   155篇
  2021年   1496篇
  2020年   2781篇
  2019年   3455篇
  2018年   3471篇
  2017年   3933篇
  2016年   4608篇
  2015年   3946篇
  2014年   4800篇
  2013年   23523篇
  2012年   4423篇
  2011年   3480篇
  2010年   3796篇
  2009年   4740篇
  2008年   3673篇
  2007年   3235篇
  2006年   3870篇
  2005年   3875篇
  2004年   3385篇
  2003年   3026篇
  2002年   2812篇
  2001年   3134篇
  2000年   2985篇
  1999年   3041篇
  1998年   2825篇
  1997年   2662篇
  1996年   2573篇
  1995年   2409篇
  1994年   2381篇
  1993年   2329篇
  1992年   2512篇
  1991年   2384篇
  1990年   2212篇
  1989年   2133篇
  1988年   2136篇
  1987年   2149篇
  1986年   2119篇
  1985年   2339篇
  1984年   2474篇
  1983年   2253篇
  1982年   2357篇
  1981年   2322篇
  1980年   2162篇
  1979年   2161篇
  1978年   2138篇
  1977年   2118篇
  1976年   1916篇
  1975年   1934篇
  1974年   2008篇
  1973年   1872篇
  1972年   1469篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
111.
Evaluated the effect of varied physician affect on subject recall, anxiety, and perceptions in a simulated tense and ambiguous medical situation. Forty women at risk for breast cancer viewed videotapes of an oncologist presenting--with either worried or nonworried affect--mammogram results. Although the mammogram results and the oncologist were the same in both presentation, analyses indicated that, compared to the women receiving the results from a nonworried physician, the women receiving the results from a worried physician recalled significantly less information, perceived the clinical situation as significantly more severe, reported significantly higher levels of state anxiety, and had significantly higher pulse rates. These results suggest that physician affect plays a critical role in patient reaction to medical information. Implications for compliance research, patient satisfaction, and physician training are discussed.  相似文献   
112.
The ability of two species of tits to remember the location and/or features of an object was tested in a delayed-matching-to-sample procedure. Three values of retention interval between presentation of the sample stimulus and the choice--30 sec, 5 min, and 15 min--were used. Both species performed at above-chance level at all retention intervals, and there was no significant decline in accuracy with increasing interval. A pool of 100 stimulus objects was used, but the results of control trials indicated that the birds responded primarily to location rather than stimulus features of the object itseif. Although the food-storing marsh tit tended to perform at a higher level than the non-storing great tit, the only significant difference between the species was in the first 50 trials of the first treatment, when the birds were acquiring the task. The results are discussed in relation to the hypothesized special memory capacity of food-storing birds.  相似文献   
113.
114.
Journal of Religion and Health - Exposure to environmental tobacco smoke (ETS) is associated with increased risk of disease and death. Reports on ETS and religion are lacking. Data from the...  相似文献   
115.
116.
117.
As the complexity of the challenges presented by our interactions with our planet continues to grow, we must develop new modes of knowledge production. In these modes, distinctions between multidisciplinary and inter-disciplinary activities and processes have renewed importance. There are at least two distinct types of interdisciplinary activities distinguished by the disciplinary breadth they attempt to bridge. In the narrow case, reductionist processes reveal a common underlying principle or process which can serve as a Rosetta stone. In the broad case, no such common arbiter exists. Investigators must develop integrating vocabulary in the context of the full breadth of their work. His primary activities are the fostering of university-wide interdisciplinary research and curriculum programs focused on global change with the goal of developing Columbia into a world leader in issues related to global stewardship.  相似文献   
118.
119.
Three experiments, each using a single group of pigeons, are reported. In Experiment 1 subjects were initially trained with two stimuli, one of which was always followed by food, the other being reinforced according to a 50% partial reinforcement schedule. Subsequently a serial procedure was adopted in which an additional stimulus, C, was consistently followed by the partially reinforced CS. A second additional stimulus, A, was followed on half of its occurrences by the continuously reinforced CS, its remaining presentations being followed by nothing. The rate of autoshaped keypecking was substantially greater during A than during C. In the remaining experiments subjects received first-order conditioning with a single stimulus that was either partially (Experiment 2) or continuously (Experiment 3) reinforced. The stimuli A and C were then again introduced for serial autoshaping. Stimulus A was occasionally paired with the CS and occasionally followed by nothing, whereas stimulus C was always followed by the CS. As in Experiment 1, the rate of responding during A was greater than during C. It is proposed that one influence on the rate of autoshaped keypecking during a CS is the accuracy with which the immediate consequences of that CS are predicted.  相似文献   
120.
A child's adjustment to wartime stress is reliant not only on individual responses and qualities, but very significantly on the availability of support that they may receive from their parent or caregivers and quality of relationships. Strengthening parental support has the potential to be valuable. A pilot two-arm randomised controlled trial investigated the feasibility of delivering and evaluating the “Caring for Children Through Conflict and Displacement” intervention with caregivers in the West Bank. Feasibility to recruit and train non-specialist staff on-the-ground to screen families for eligibility, collect outcome data, deliver the intervention and to recruit and retain families in the study were examined. Research staff and intervention facilitators were successfully appointed in the field, screened participants and delivered the intervention to 120 caregivers, collecting outcome measures pre-and post-delivery. All families completed the outcome measures, with very little missing data. This indicated that the intervention can be delivered feasibly and evaluated with families in this humanitarian context. Preliminary outcome data showed promise that the intervention may have the potential to both improve family functioning and reduce children's problem behaviour. Implications of family-focused initiatives, particularly within a conflict/post-conflict context for the prevention of several negative health and social outcomes directions, are discussed.  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