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   196669篇
  免费   8456篇
  国内免费   163篇
  2020年   2875篇
  2019年   3538篇
  2018年   3857篇
  2017年   4294篇
  2016年   4891篇
  2015年   4006篇
  2014年   4889篇
  2013年   23800篇
  2012年   5468篇
  2011年   4684篇
  2010年   4291篇
  2009年   4985篇
  2008年   4746篇
  2007年   4360篇
  2006年   4728篇
  2005年   4619篇
  2004年   4067篇
  2003年   3672篇
  2002年   3488篇
  2001年   4211篇
  2000年   4024篇
  1999年   3742篇
  1998年   2933篇
  1997年   2729篇
  1996年   2645篇
  1995年   2503篇
  1994年   2448篇
  1993年   2409篇
  1992年   3173篇
  1991年   2962篇
  1990年   2874篇
  1989年   2680篇
  1988年   2673篇
  1987年   2652篇
  1986年   2664篇
  1985年   2888篇
  1984年   2818篇
  1983年   2591篇
  1982年   2472篇
  1981年   2429篇
  1980年   2260篇
  1979年   2633篇
  1978年   2378篇
  1977年   2296篇
  1976年   2138篇
  1975年   2370篇
  1974年   2495篇
  1973年   2445篇
  1972年   1936篇
  1968年   1899篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
111.
112.
113.
114.
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   
115.
Previous research demonstrates that older adults are poor at dual tasking, but there is less agreement on whether their decrement is worse than that predicted from single-task performance. This study investigated whether task domain moderates dual-task costs in old age. In two experiments, young and older adults retrieved either previously learned associates (episodic retrieval) or overlearned category members (semantic retrieval) under single or working-memory load conditions, using cued recall (Experiment 1) and recognition (Experiment 2) procedures. In both experiments the proportional costs of dual tasking were age invariant for semantic retrieval but were particularly marked for episodic retrieval, although the size of the age effect was reduced in recognition compared to cued recall. The data suggest that age effects in dual tasking may be domain specific.  相似文献   
116.
117.
118.
Some languages create the impression of being stress timed. Claims have been made that this timing of stressed syllables enables the listener to predict the future locations of informative parts later in a sentence. The fact that phoneme monitoring is delayed when targets in a spoken sentence are displaced has been taken as supporting this claim (Meltzer, Martin, Bergfeld Mills, Imhoff and Zohar, 1976). In the present study temporal displacement was induced without introducing phonetic discontinuities. In Dutch sentences a word just in advance of a target-bearing word was replaced by another one differing in length. Results show that the temporal displacement per se did not have any effect on phoneme-monitoring reaction times. Implications for a theory of fpeech processing are discussed.  相似文献   
119.
Evaluated the effect of varied physician affect on subject recall, anxiety, and perceptions in a simulated tense and ambiguous medical situation. Forty women at risk for breast cancer viewed videotapes of an oncologist presenting--with either worried or nonworried affect--mammogram results. Although the mammogram results and the oncologist were the same in both presentation, analyses indicated that, compared to the women receiving the results from a nonworried physician, the women receiving the results from a worried physician recalled significantly less information, perceived the clinical situation as significantly more severe, reported significantly higher levels of state anxiety, and had significantly higher pulse rates. These results suggest that physician affect plays a critical role in patient reaction to medical information. Implications for compliance research, patient satisfaction, and physician training are discussed.  相似文献   
120.
The ability of two species of tits to remember the location and/or features of an object was tested in a delayed-matching-to-sample procedure. Three values of retention interval between presentation of the sample stimulus and the choice--30 sec, 5 min, and 15 min--were used. Both species performed at above-chance level at all retention intervals, and there was no significant decline in accuracy with increasing interval. A pool of 100 stimulus objects was used, but the results of control trials indicated that the birds responded primarily to location rather than stimulus features of the object itseif. Although the food-storing marsh tit tended to perform at a higher level than the non-storing great tit, the only significant difference between the species was in the first 50 trials of the first treatment, when the birds were acquiring the task. The results are discussed in relation to the hypothesized special memory capacity of food-storing birds.  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