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   95842篇
  免费   3834篇
  国内免费   34篇
  2020年   988篇
  2019年   1263篇
  2018年   1704篇
  2017年   1781篇
  2016年   1848篇
  2015年   1320篇
  2014年   1628篇
  2013年   7300篇
  2012年   2992篇
  2011年   3040篇
  2010年   1915篇
  2009年   1797篇
  2008年   2708篇
  2007年   2656篇
  2006年   2432篇
  2005年   2207篇
  2004年   2075篇
  2003年   1906篇
  2002年   1949篇
  2001年   2855篇
  2000年   2667篇
  1999年   2078篇
  1998年   1017篇
  1997年   892篇
  1992年   1817篇
  1991年   1662篇
  1990年   1679篇
  1989年   1543篇
  1988年   1579篇
  1987年   1499篇
  1986年   1552篇
  1985年   1601篇
  1984年   1313篇
  1983年   1251篇
  1982年   954篇
  1981年   908篇
  1979年   1510篇
  1978年   1054篇
  1977年   958篇
  1976年   960篇
  1975年   1266篇
  1974年   1420篇
  1973年   1501篇
  1972年   1213篇
  1971年   1150篇
  1970年   1107篇
  1969年   1168篇
  1968年   1461篇
  1967年   1304篇
  1966年   1171篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
In this essay I address three ways in which Edwards can inform Christian understanding of public life. First I show how Edwards provides both philosophical and theological rationales for social engagement and thereby resists the separation of religion from public life, and use his consideration of poverty as an illustration. Part II examines Edwards's dialectical treatment of patriotism, demonstrating both its importance to the Christian life and its susceptibility to deceptive accommodation to culture. Finally, in Part III I discuss Edwards's use of "national covenant," which despite its temptation to chauvinism Edwards used to undermine national pride. In the conclusion I assess what we can use from Edwards for contemporary Christian understandings of public life.  相似文献   
65.
66.
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   
67.
The Evaluative Space Model of emotions allows for the coactivation of positive‐appetitive and negative‐avoidant systems, but few studies have examined mixed emotions in child development. Existing research suggests children's understanding of opposite valence emotion combinations emerges by approximately 11 years of age. However, it is not yet clear whether various opposite valence combinations are understood at different ages, nor whether children can understand them in others before they have experienced such mixed emotions themselves. Semi‐structured interviews with 97 children investigated whether they regarded six combinations of opposite valence mixed emotions as possible, could provide reasons for them, and report their own experience of each in the context of mother–child relationships. Both understanding that such combinations are possible and ability to provide reasons for them increased after age 6 and up to age 11, but were still incomplete in 12‐year‐olds. Understanding of different opposite valence combinations developed at different rates. At each age, fewer children who showed understanding of these combinations in others reported having had a similar experience themselves. The findings suggest a need to systematically examine a range of mixed emotions in order to develop a comprehensive theory of the development of mixed emotion understanding. They also suggest extending research into adolescence.  相似文献   
68.
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   
69.
Intention is theorized as the proximal determinant of behavior in some theories of motivation, but the need to understand predictors of action control (i.e., translating an intention into behavior) is warranted to tailor physical activity intervention efforts. The purpose of this study was to examine constructs of the transtheoretical model of behavior change (TTM) as predictors of physical activity intention-behavior profiles across 6 months in a large Canadian sample (N = 1,192). Results showed that 5 of the 8 possible intention-behavior profiles had a substantial number of participants: nonintenders, unsuccessful adopters, successful adopters, unsuccessful maintainers, and successful maintainers. Constructs of the TTM distinguished (p < .01) intention-behavior profiles. Self-efficacy and the behavioral processes of change were particularly good predictors of action control (p < .01), but disaggregated beliefs and processes identified specific intervention targets for successful physical activity adoption and maintenance. The results validate that both action planning and action control are important when understanding physical activity behavior.  相似文献   
70.
The authors used recursive partitioning methods to identify combinations of baseline characteristics that predict 2-year physical activity success in each of 3 physical activity interventions delivered in the multisite Activity Counseling Trial. The sample consisted of 874 initially sedentary primary care patients, ages 35-75 years, who were at risk for cardiovascular disease. Predictors of 2-year success were specific to each intervention and represented a range of domains, including physiological, demographic, psychosocial, health-related, and environmental variables. The results indicate how specific patient subgroups (e.g., obese, unfit individuals; high-income individuals in stable health) may respond differently to varying levels and amounts of professional assistance and support. The methods used provide a practical first step toward identifying clinically meaningful patient subgroups for further systematic investigation.  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