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   61350篇
  免费   2593篇
  国内免费   724篇
  2020年   721篇
  2019年   823篇
  2018年   1137篇
  2017年   1209篇
  2016年   1238篇
  2015年   876篇
  2014年   1081篇
  2013年   4635篇
  2012年   1939篇
  2011年   2040篇
  2010年   1405篇
  2009年   1295篇
  2008年   1879篇
  2007年   1907篇
  2006年   1764篇
  2005年   1513篇
  2004年   1374篇
  2003年   1271篇
  2002年   1303篇
  2001年   1721篇
  2000年   1681篇
  1999年   1306篇
  1998年   624篇
  1997年   647篇
  1996年   596篇
  1995年   595篇
  1992年   1146篇
  1991年   1015篇
  1990年   1077篇
  1989年   962篇
  1988年   1001篇
  1987年   955篇
  1986年   989篇
  1985年   933篇
  1984年   822篇
  1983年   771篇
  1979年   927篇
  1978年   679篇
  1977年   590篇
  1976年   584篇
  1975年   747篇
  1974年   858篇
  1973年   924篇
  1972年   694篇
  1971年   696篇
  1970年   636篇
  1969年   712篇
  1968年   843篇
  1967年   770篇
  1966年   713篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
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   
56.
According to the Body‐Specificity Hypothesis (BSH), people implicitly associate positive ideas with the side of space on which they are able to act more fluently with their dominant hand. Though this hypothesis has been rigorously tested across a variety of populations and tasks, the studies thus far have only been conducted in linguistic and cultural communities which favor the right over the left. Here, we tested the effect of handedness on implicit space‐valence mappings in Tibetan practitioners of Bön who show a strong religious preference for the left, in comparison to an English group. Results showed that Bön right‐handers tended to implicitly associate positive valence more strongly with their dominant side of space despite strong explicit associations between the left and goodness in their religion. This pattern of results found in Bön participants was indistinguishable from that found in English speakers. The findings of the present study support the BSH, demonstrating that space‐valence mappings in people's minds are shaped by their bodily experience, which appears to be independent of space‐valence mappings enshrined in cultural conventions.  相似文献   
57.
安东尼·吉登斯是当代国外马克思主义的代表性人物之一.在对历史事件的分析中,吉登斯既肯定了后现代主义对于宏大叙事的"解构",拒斥各种寻求普适性规律的观念及其理论形式,又承认能够对某些确定性的历史事件予以辨认与概括,尝试提出一种与马克思相异的历史解释理论.  相似文献   
58.
By roughly 6 years of age, children acquire the stereotype that men are more competent than women in science, technology, engineering, and mathematics (STEM), potentially leading to greater trust in scientific information provided by men. This study tested whether 3- to 8-year-old children differentially endorsed conflicting information about science and toys presented by male and female informants depicted as a ‘man’ and ‘woman’ (Exp1) or ‘scientists’ (Exp2). Children were expected to endorse toy testimony from gender-matched informants; thus, the key question concerned endorsement of science testimony. In Exp1 (N = 149), boys and girls showed a same-gender informant preference for toy testimony; however, girls endorsed the male informant's testimony more for science than for toys – but only when tested by a male experimenter. In Exp2 (N = 264), boys and girls showed a same-gender preference, irrespective of content. Findings suggest that STEM-related gender stereotypes might lead girls to trust scientific information presented by men over women in certain contexts.  相似文献   
59.
A time-sharing paradigm was used to study potential interference effects of concurrent successive-auditory/vocal, successive-visual/motor, simultaneous-auditory/vocal, and simultaneous-visual/motor tasks on right- and left-handed manual-motor behaviors of differential levels of difficulty. Participants were selected from each of three developmental levels from 9 through 20 years of age. Results suggested that processing style (i.e., successive or simultaneous) interacts with modality (i.e., auditory/vocal or visual/motor) in terms of lateralized interference effects; however, potential effects due to age level were obfuscated by differential concurrent-task difficulties.  相似文献   
60.
Previous work on children's intuitive knowledge about the natural world has documented their difficulty in acquiring an overarching concept of biological life that includes plants as well as humans and non‐human animals. It has also suggested that the acquisition of fundamental biological concepts like alive and die may be influenced by the language used to describe them, as evidenced by differences between English‐ and Indonesian‐speaking children's performance in tasks involving these concepts. Here, we examine one particularly important source of linguistic information available to children during this acquisition process: everyday conversations with their parents. We take a cross‐linguistic approach in analysing the evidence available to English‐ and Indonesian‐speaking children as they acquire meanings for words corresponding to the concepts alive and die . Our analysis illustrates that young children acquiring English and Indonesian are faced with distinct problems, but that parental input in both languages does little to support the acquisition of broad, inclusive biological concepts.  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