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   157455篇
  免费   6713篇
  国内免费   105篇
  2020年   1714篇
  2019年   2102篇
  2018年   2964篇
  2017年   3030篇
  2016年   3215篇
  2015年   2280篇
  2014年   2721篇
  2013年   13186篇
  2012年   4934篇
  2011年   5136篇
  2010年   3325篇
  2009年   3371篇
  2008年   4619篇
  2007年   4689篇
  2006年   4161篇
  2005年   3777篇
  2004年   3667篇
  2003年   3409篇
  2002年   3470篇
  2001年   4712篇
  2000年   4487篇
  1999年   3505篇
  1998年   1920篇
  1997年   1674篇
  1996年   1690篇
  1995年   1546篇
  1993年   1535篇
  1992年   2932篇
  1991年   2786篇
  1990年   2767篇
  1989年   2552篇
  1988年   2493篇
  1987年   2372篇
  1986年   2435篇
  1985年   2541篇
  1984年   2181篇
  1983年   1908篇
  1982年   1503篇
  1979年   2221篇
  1978年   1690篇
  1975年   1873篇
  1974年   2117篇
  1973年   2220篇
  1972年   1856篇
  1971年   1700篇
  1970年   1551篇
  1969年   1574篇
  1968年   1978篇
  1967年   1811篇
  1966年   1646篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Gay marriages (as such) are not as yet allowed anywhere but the demand for them is increasing. Most countries take a liberal attitude towards marriage: few obstacles are put in its way. But objections to gay marriages continue to be raised. These objections are refuted and the case for gay marriage is assessed through the prism of various forms of liberalism. The normative argument for allowing gay marriage is shown to be both strong and consistent with many of the values upheld by the opponents of such unions.  相似文献   
102.
In three experiments we studied the relationship between contextual conditioning and the reinstatement of extinguished lever pressing that occurs when noncontingent food is introduced following extinction. In all three experiments the non-contingent food was presented off-baseline (with the response levers not present). On subsequent tests, with the response levers present, animals that had been exposed to food showed more reinstatement of lever pressing than control animals. This finding rules out alternative mechanisms for the reinstated responding that rely on the interaction of non-contingent food and responding, such as superstitious reinforcement or the discriminative after-effects of food. In addition, in each experiment we demonstrated that manipulations known to affect contextual conditioning (signalling the food in Experiment 1, context extinction in Experiment 2, and switching contexts in Experiment 3) reduced the reinstatement. These results are consistent with the claim that contextual conditioning is important in controlling instrumental conditioning and closely parallel findings concerning the reinstatement of Pavlovian responsing following extinction.  相似文献   
103.
We test the emotion-response congruency hypothesis, which predicts that the consequences of socially sharing one's negative emotions depend on the congruency between the shared emotion and the response that is obtained from the interaction partner. Experiment 1a shows that the response that people prefer is dependent on the specific emotion shared. Experiment 1b, however, reveals that the responses that interaction partners provide do not differ across emotions. Yet, and crucially, Experiment 2 shows that the outcomes of sharing are affected by the congruency between the response that people receive and the emotion they share, thus supporting the emotion-response congruency hypothesis. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
104.
105.
106.
OBJECTIVE: Compare the efficacy of a multicomponent social support intervention to standard-of-care counseling on medication adherence among HIV-infected patients initiating antiretroviral therapy. DESIGN: Randomized controlled trial. Generalized estimating equations tested for differences in the percentage of participants achieving 90% adherence. MAIN OUTCOME MEASURES: Pill-taking, electronically monitored over 6 consecutive months; plasma viral load (VL), assessed at 3 and 6 months following initiation of therapy. RESULTS: Of 226 participants who were randomized and began the trial, 87 (38%) were lost to the study by 6 months. The proportion of adherent participants declined steadily over time, with no time by group interaction. Sustained adherence was associated with increased odds of achieving an undetectable VL (OR=1.78; 95% CI=1.01, 3.13). In intention-to-treat analyses, a larger proportion of the intervention group than the control group was adherent (40.15% vs. 27.59%, p=.02) and achieved an undetectable VL p=.04). However, the majority of participants who remained on study experienced some reduction in VL (>or=1-log drop or undetectable), regardless of experimental condition. CONCLUSION: The multicomponent social support intervention significantly improved medication adherence over standard-of-care counseling; evidence for improved virologic outcomes was inconsistent. Early discontinuation of care and treatment may be a greater threat to the health of HIV patients than imperfect medication-taking.  相似文献   
107.
In this study, we explored the structure of pupils’ creativity in primary education following the Amusement Park Theory, by investigating undiscovered linkages between the domains of writing, mathematics, and drawing. More specifically, we examined: (a) whether some domains and general thematic areas are more closely related to each other than to others, (b) whether literacy and mathematical ability are specific underlying traits of creativity in writing and mathematics, respectively, and (c) whether intelligence and divergent thinking are related to creativity in all domains. The sample consisted of 331 Dutch 4th grade pupils. For each research question, a model was analyzed using structural equation modeling. We found creativity in mathematics and creativity in writing to be most similar, followed by creativity in mathematics and creativity in drawing, with creativity in writing and creativity in drawing being least similar. Additionally, we found evidence for several underlying traits (i.e., literacy ability and mathematical ability) and initial requirements of creativity (i.e., intelligence and divergent thinking), none of which were important for creativity in only one domain, and of which only intelligence was important for creativity in all domains. Herewith, our study provides insights regarding the complexity of the structure of creativity in primary education.  相似文献   
108.
109.
This study examined the role of illness uncertainty in pain coping among women with fibromyalgia (FM), a chronic pain condition of unknown origin. Fifty-one FM participants completed initial demographic and illness uncertainty questionnaires and underwent 10-12 weekly interviews regarding pain, coping difficulty, and coping efficacy. Main outcome measures included weekly levels of difficulty coping with FM symptoms and coping efficacy. Multilevel analyses indicated that pain elevations for those high in illness uncertainty predicted increases in coping difficulty. Furthermore, when participants had more difficulty coping, they reported lower levels of coping efficacy. Results were consistent with hypothesized effects. Illness uncertainty accompanied by episodic pain negatively influenced coping efficacy, an important resource in adaptation to FM.  相似文献   
110.
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