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   13975篇
  免费   598篇
  国内免费   13篇
  2023年   75篇
  2021年   120篇
  2020年   216篇
  2019年   267篇
  2018年   361篇
  2017年   359篇
  2016年   379篇
  2015年   271篇
  2014年   351篇
  2013年   1548篇
  2012年   621篇
  2011年   662篇
  2010年   397篇
  2009年   422篇
  2008年   576篇
  2007年   568篇
  2006年   581篇
  2005年   534篇
  2004年   487篇
  2003年   508篇
  2002年   490篇
  2001年   253篇
  2000年   226篇
  1999年   221篇
  1998年   199篇
  1997年   214篇
  1996年   194篇
  1995年   170篇
  1994年   163篇
  1993年   159篇
  1992年   141篇
  1991年   154篇
  1990年   138篇
  1989年   125篇
  1988年   94篇
  1987年   120篇
  1986年   131篇
  1985年   168篇
  1984年   166篇
  1983年   143篇
  1982年   134篇
  1981年   144篇
  1980年   125篇
  1979年   113篇
  1978年   122篇
  1977年   111篇
  1976年   110篇
  1975年   95篇
  1974年   108篇
  1973年   88篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
The purpose of this meta-analysis of randomized controlled trials was to evaluate the efficacy of psychological interventions for adults with noncancerous chronic low back pain (CLBP). The authors updated and expanded upon prior meta-analyses by using broad definitions of CLBP and psychological intervention, a broad data search strategy, and state-of-the-art data analysis techniques. All relevant controlled clinical trials meeting the inclusion criteria were identified primarily through a computer-aided literature search. Two independent reviewers screened abstracts and articles for inclusion criteria and extracted relevant data. Cohen's d effect sizes were calculated by using a random effects model. Outcomes included pain intensity, emotional functioning, physical functioning (pain interference or pain-specific disability, health-related quality of life), participant ratings of global improvement, health care utilization, health care provider visits, pain medications, and employment/disability compensation status. A total of 205 effect sizes from 22 studies were pooled in 34 analyses. Positive effects of psychological interventions, contrasted with various control groups, were noted for pain intensity, pain-related interference, health-related quality of life, and depression. Cognitive-behavioral and self-regulatory treatments were specifically found to be efficacious. Multidisciplinary approaches that included a psychological component, when compared with active control conditions, were also noted to have positive short-term effects on pain interference and positive long-term effects on return to work. The results demonstrated positive effects of psychological interventions for CLBP. The rigor of the methods used, as well as the results that reflect mild to moderate heterogeneity and minimal publication bias, suggest confidence in the conclusions of this review.  相似文献   
25.
Suicide and homicide rates by age were analyzed for Canada and the United States, indicating that suicide is higher in Canada and that homicide is higher in the United States. Results indicated a positive association between homicide and suicide rates in the United States but these two rates of death were not significantly associated in Canada. Holinger (1987) had associated the relative size of the cohort to the rates of suicide and homicide in young people in the United States. The more current data in both countries did not support Holinger's results. Using the measure devised by Easterlin (1980) and Ahlburg and Schapiro (1984) –that is, the proportion of youths aged 15–24 relative to adults aged 25–64–the correlation between the size of the youth cohort and the suicide rate of youths aged 15–24 was negative. It is concluded that the two patterns in these two countries may be explained from a historical perspective.  相似文献   
26.
Given the rapid proliferation of smartphone applications and data aggregation websites, in many situations people can use decision aids to guide their choices. For example, they may consider whether to use a navigation device to check the fastest route or whether to use a price comparison website to find the cheapest deal. In what circumstances will subjects use a costly comparison decision aid (which I refer to as “checking”) to choose for them? In six studies, I investigate the impact of the number of available alternatives and checking's attractiveness on the decision to check. While at first increasing the attractiveness of checking led to higher checking rates, a further increase in the number of available alternatives (and thus checking's attractiveness) did not increase the checking rate. Surprisingly, even when checking had a 40% higher expected value compared with not checking, the observed checking rate was below 45%, contrary to risk and ambiguity aversion predictions. Furthermore, labeling the checking alternative as the default had no impact on its choice rate. I find large individual differences in decisions to check. Surprisingly, subjects' initial decisions had high predictive power over their subsequent checking rates, even after 100 trials with full feedback. I propose two simple learning models that capture well the aggregated results.  相似文献   
27.
28.
29.
30.
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