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   13807篇
  免费   586篇
  国内免费   13篇
  2023年   72篇
  2021年   117篇
  2020年   214篇
  2019年   262篇
  2018年   358篇
  2017年   352篇
  2016年   374篇
  2015年   269篇
  2014年   347篇
  2013年   1536篇
  2012年   615篇
  2011年   656篇
  2010年   395篇
  2009年   419篇
  2008年   567篇
  2007年   564篇
  2006年   577篇
  2005年   520篇
  2004年   482篇
  2003年   507篇
  2002年   488篇
  2001年   246篇
  2000年   225篇
  1999年   220篇
  1998年   201篇
  1997年   215篇
  1996年   196篇
  1995年   170篇
  1994年   161篇
  1993年   154篇
  1992年   141篇
  1991年   154篇
  1990年   136篇
  1989年   125篇
  1988年   89篇
  1987年   117篇
  1986年   128篇
  1985年   162篇
  1984年   163篇
  1983年   140篇
  1982年   131篇
  1981年   143篇
  1980年   125篇
  1979年   109篇
  1978年   119篇
  1977年   109篇
  1976年   107篇
  1975年   94篇
  1974年   104篇
  1973年   85篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
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   
13.
14.
Godden  David 《Topoi》2019,38(4):725-750
Topoi - Robert Fogelin argued that the efficacy of our acts of reasons-giving depends on the normalcy of our discourse—to the extent that discourse is not normal disagreements occurring in it...  相似文献   
15.
16.
Pregnancy reflects a common experience for women in today's workforce, yet recent data suggest that some women scale back or leave the workforce following childbirth. Considering these effects on women's careers, researchers have sought to understand the underlying dynamics of these decisions. Here, we explore a paradoxical reason for weakened postpartum career attitudes: help that women receive during pregnancy. We integrate stereotype threat and benevolent sexism theories to explain how the effects of help on postpartum intentions to quit may be transmitted through reductions in work self-efficacy. In doing so, we consider the role of perceived impact—or the extent to which help interferes with versus enables women's perceived ability to continue performing their work role. Results of a weekly diary study of 105 pregnant employees suggest that work-interfering help led to decreased self-efficacy for work during the following week. Furthermore, there was an indirect effect of average help received at work during pregnancy on postpartum intentions to quit the workforce through reductions in work self-efficacy that was stronger insofar as help was work-interfering versus work-enabling. Taken together, our results highlight unintended negative consequences that occur when others provide ineffective support to women at work during pregnancy.  相似文献   
17.
Main clause phenomena (MCPs) are syntactic constructions that occur predominantly or exclusively in main clauses. I propose a processing explanation for MCPs. Sentence processing is easiest at the beginning of the sentence (requiring less search); this follows naturally from widely held assumptions about sentence processing. Because of this, a wider variety of constructions can be allowed at the beginning of the sentence without overwhelming the sentence‐processing mechanism. Unlike pragmatic and grammatical accounts of MCPs, the processing account predicts avoidance of MCPs in non‐initial main clauses (non‐initial coordinate clauses and premodified clauses). A corpus study supports these predictions, but it is somewhat inconclusive. A further corpus study examines another type of syntactic construction, premodifying adjunct phrases (“openers”); the prediction here is that less common types of opener will be especially avoided in non‐initial contexts. The prediction is confirmed, supporting the processing view of rare constructions.  相似文献   
18.
Cancellation tests are commonly used in the clinical assessment of visuospatial function, but there has been little study of task characteristics influencing performance. This study was designed to assess factors which affect cancellation performance. Sixteen healthy subjects sequentially performed four random-array letter cancellation tasks. The forms contained 50 and 100 stimuli and target:distractor (T/D) ratios of 1:4 and 1:9 with target letter “A” and randomly selected letter distractors. The primary performance measure was calculated as the number of correctly cancelled targets divided by the time to complete the task, corrected for accuracy. This measure revealed a strong effect of T/D ratio (p< .0001), with performance adversely affected by higher proportion of distractors. There was no effect of stimulus number. This suggests that T/D ratio should be considered in cancellation test design and interpretation.  相似文献   
19.
20.
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