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   32306篇
  免费   1222篇
  国内免费   18篇
  2019年   423篇
  2018年   577篇
  2017年   636篇
  2016年   592篇
  2015年   442篇
  2014年   492篇
  2013年   2505篇
  2012年   870篇
  2011年   987篇
  2010年   656篇
  2009年   646篇
  2008年   900篇
  2007年   843篇
  2006年   781篇
  2005年   661篇
  2004年   611篇
  2003年   657篇
  2002年   613篇
  2001年   1206篇
  2000年   1194篇
  1999年   863篇
  1998年   378篇
  1997年   306篇
  1996年   305篇
  1995年   309篇
  1994年   310篇
  1992年   722篇
  1991年   697篇
  1990年   661篇
  1989年   612篇
  1988年   587篇
  1987年   580篇
  1986年   546篇
  1985年   612篇
  1984年   475篇
  1983年   374篇
  1979年   466篇
  1978年   352篇
  1977年   332篇
  1976年   305篇
  1975年   416篇
  1974年   423篇
  1973年   479篇
  1972年   384篇
  1971年   320篇
  1970年   309篇
  1969年   330篇
  1968年   381篇
  1967年   339篇
  1966年   388篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
321.
The influence of prior linguistic predictive and nonpredictive context on the comprehension of reversible passive sentences was investigated in 16 adults with aphasia. Eight subjects were classified as fluent and 8 as nonfluent. Subjects were presented with the sentences in isolation and preceded by nonpredictive and predictive contextual paragraphs. The overall results indicated that the subjects benefited significantly from the prior contextual narratives regardless of whether the paragraphs were predictive or nonpredictive. There were no significant differences between the two subject groups. The significant facilitation generated by the nonpredictive context suggests that redundancy of information may play a role in comprehension.  相似文献   
322.
A total of 178 reading disabled children were randomly assigned to one of three treatment conditions providing training in word recognition and decoding skills (DS), oral and written language (OWLS), or classroom survival skills (CSS. an alternative treatment control). Pre- and post-treatment comparisons on an array of standardized and experimental measures indicated that the two experimental treatments (DS, OWLS) resulted in improvement on selected tests significantly greater than that resulting from a third treatment intervention which controlled for treatment time and individual attention (CSS). Effects specific to each experimental treatment were identified, as well as some generalized treatment advantages shared by both experimental groups at post-test. These results indicate that some of the deficits associated with developmental dyslexia are amenable to treatment. Greater generalization of treatment effects was observed following the DS than the OWLS treatment. While DS-instructed children exhibited better word recognition skills, however, their knowledge of grapheme-phoneme correspondence rules was not improved. Several OWLS-specific effects observed on experimental reading and language measures were not replicated on standardized tests which purport to measure the same skills. These results are discussed with respect to (i) possible mechanisms by which disabled readers may acquire word recognition skills, (ii) their failure to acquire and use grapheme-phoneme correspondence rules, and (iii) a possible reduced tendency in the present population to generalize newly acquired specific knowledge to related knowledge domains.  相似文献   
323.
Two alternative hypotheses were considered concerning the process of prolonged search for an uncommon word in response to hearing its definition. One alternative is that a conscious retrieval effort brings the target progressively closer to threshold. The second is that the retrieval process is a random neural exploration outside of conscious control. A tachistoscopic probe was devised to compare word recognition thresholds after 10 sec versus 30 sec of presumed search time. Results failed to show a difference between the two delay conditions and were interpreted as inconsistent with the first alternative but consistent with the second.  相似文献   
324.
Psychological stress has been shown to affect immune system status and function, but most studies of this relationship have focused on acute stress and/or laboratory situations. The present study compared total numbers of leukocytes and lymphocyte subpopulations (determined by flow cytometry) and antibody titers to latent and nonlatent viruses among a group of chronically stressed individuals living near the damaged Three Mile Island (TMI) nuclear power plant with those of a demographically comparable control group. Urinary catecholamine and cortisol levels were also examined. Residents of the TMI area exhibited greater numbers of neutrophils, which were positively correlated with epinephrine levels. The TMI group also exhibited fewer B lymphocytes, T-suppressor/cytotoxic lymphocytes, and natural killer cells. Antibody titers to herpes simplex were significantly different across groups as well, whereas titers to nonlatent rubella virus as well as IgG and IgM levels were comparable.  相似文献   
325.
This work has received financial support from FONDECYT (Project 1111-88). The authors also acknowledge the helpful comments of Dr. Bruce Cassels.  相似文献   
326.
327.
Judith S. Bridges 《Sex roles》1989,20(3-4):205-211
In order to examine sex differences in occupational values, college women and men rated the importance of 18 job characteristics for their career choice. In addition, they indicated which three were the most important and which three were the least important. The findings showed that, in comparison to males, females attached greater importance to a large variety of values, and these results are discussed in relation to career choice.This research was supported by a grant from the University of Connecticut Research Foundation.  相似文献   
328.
Using recall of clinical protocols as a measure of expertise in medicine has yielded disappointingly small effects. Experiments using recall of clinical laboratory data are presented to provide an explanation. In one experiment, subjects either deliberately memorized or first diagnosed and then were incidentally asked for memory. With incidental instructions, experts recalled over twice as much data as did students, but with memorization instructions, student performance approximated that of experts. Experts also showed a large advantage over students in incidental recall of data that were not relevant to the problem solution. These results suggest that expert processing in this "discrete, independent inputs" domain requires effortful analysis with minimal reliance on default values, rather than relatively effortless pattern perception reported in highly visual areas of expertise. For this area, intentional memory is a misleading measure of expertise. However, incidental memory is a valuable measure of processing during diagnosis.  相似文献   
329.
330.
Twenty-four-hour sleep-wake patterns in a nursing home population   总被引:1,自引:0,他引:1  
Sleep-activity patterns were objectively recorded over a 24-hr period in 19 elderly nursing home residents. On average, both sleep and wake times were observed during every hour of the 24 recorded hours; however, the sleep pattern of the residents was fragmented so that they rarely experienced even a single hour of consolidated time spent sleeping. It is hypothesized that several independent factors, including compensation for lost sleep, increased total time in bed, weakening of social constraints, and deterioration of the circadian sleep-wake rhythm, are interacting to produce this increase in sleep fragmentation.  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