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   14228篇
  免费   684篇
  国内免费   7篇
  2023年   118篇
  2022年   139篇
  2021年   198篇
  2020年   274篇
  2019年   329篇
  2018年   479篇
  2017年   494篇
  2016年   475篇
  2015年   349篇
  2014年   367篇
  2013年   1563篇
  2012年   780篇
  2011年   785篇
  2010年   484篇
  2009年   379篇
  2008年   598篇
  2007年   521篇
  2006年   458篇
  2005年   442篇
  2004年   350篇
  2003年   342篇
  2002年   315篇
  2001年   314篇
  2000年   315篇
  1999年   233篇
  1998年   107篇
  1997年   82篇
  1996年   91篇
  1993年   90篇
  1992年   163篇
  1991年   159篇
  1990年   162篇
  1989年   134篇
  1988年   139篇
  1987年   128篇
  1986年   131篇
  1985年   135篇
  1984年   128篇
  1983年   102篇
  1979年   134篇
  1976年   78篇
  1975年   87篇
  1974年   118篇
  1973年   107篇
  1972年   88篇
  1971年   94篇
  1970年   84篇
  1969年   94篇
  1968年   93篇
  1967年   102篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Serial pattern learning was investigated in a variation of the task introduced by Nissen and Bullemer (1987). We presented an asterisk at 1 of 4 spatial locations on each trial, and Ss either responded with a keypress or observed the event. The first 4 blocks contained 10 repetitions of a 10- or 16-element pattern, and the 5th block contained a random sequence. The difference in response time on the 5th random block and the previous patterned block served as an indirect measure of pattern learning. A direct measure was obtained in a final test block in which Ss predicted the next asterisk position. Equivalent learning occurred for responding and observing with indirect measures, but observation was superior with direct measures. These findings indicate that knowledge of serial order can develop through simple perceptual experience, and this is more available to deliberate recall than is knowledge acquired while responding.  相似文献   
2.
3.
Cognitive neuropsychology provides a theoretical framework and methods that can be of value in the study of developmental disorders, but the "dissociation" logic at the centre of this approach is not well suited to the developmental context. This is illustrated with examples from specific language impairment. Within the developing language system there is ample evidence for interaction between levels of representation, with modularity emerging in the course of development. This means that one typically is seeking to explain a complex pattern of associated impairments, rather than highly selective deficits. For instance, a selective impairment in auditory processing can have repercussions through the language system and may lead to distinctive syntactic deficits that are seen in written as well as spoken language. Changes in the nature of representations and in the relationships between components of a developing system mean that cross-sectional data at a single point in development may be misleading indicators of the primary deficit. Furthermore, traditional cognitive neuropsychology places a disproportionate emphasis on representational (competence) deficits, with processing (performance) deficits being relatively neglected. Methods for distinguishing these two kinds of impairment are discussed, as well as other approaches for elucidating the underlying nature of developmental disorders.  相似文献   
4.
5.
Abstract: One claim about I , regularly made and almost universally endorsed, is that uses of the term are logically guaranteed to refer successfully (if they refer at all). The claim is only rarely formulated perspicuously or argued for. Such obscurity helps disguise the fact that those who profess to advance the claim actually turn out to support not a logical guarantee at all but merely high security through fortunate coincidence. This is not surprising. For we have no good reason to accept the claim – granted, any use of I is apt to refer successfully; but that can be explained by pragmatic features of its use. And we have some reason to reject the claim – it is notoriously difficult to see how genuine reference and guaranteed success do not exclude each other when considered as properties of the logic of any term.  相似文献   
6.
7.
8.
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   
9.
10.
A growing literature has observed a significant reduction in pain sensitivity among hypertensive animals and humans. It is uncertain whether a reduced sensitivity to pain can be observed in nonnotensive individuals who go on to develop high blood pressure. Blood pressure (BP) was reassessed in one hundred fifteen 19-year-old boys initially tested at age 14, when they were also presented with a pain stimulus (mechanical finger pressure). Hierarchical regression analyses indicated that information regarding pain tolerance improved prediction of changes in systolic and diastolic blood pressure beyond that afforded by differences in BP at age 14, parental history of hypertension, and body mass index. These analyses suggest that pain sensitivity may be associated with physiological processes involved in the development of sustained high blood pressure.  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