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   33468篇
  免费   1354篇
  国内免费   9篇
  2020年   316篇
  2019年   440篇
  2018年   590篇
  2017年   604篇
  2016年   605篇
  2015年   432篇
  2014年   542篇
  2013年   2457篇
  2012年   1007篇
  2011年   1066篇
  2010年   626篇
  2009年   624篇
  2008年   927篇
  2007年   903篇
  2006年   858篇
  2005年   775篇
  2004年   755篇
  2003年   687篇
  2002年   716篇
  2001年   1038篇
  2000年   938篇
  1999年   723篇
  1998年   398篇
  1997年   328篇
  1996年   318篇
  1992年   562篇
  1991年   550篇
  1990年   535篇
  1989年   546篇
  1988年   535篇
  1987年   500篇
  1986年   528篇
  1985年   580篇
  1984年   463篇
  1983年   437篇
  1982年   366篇
  1981年   344篇
  1979年   526篇
  1978年   388篇
  1976年   362篇
  1975年   435篇
  1974年   494篇
  1973年   512篇
  1972年   407篇
  1971年   383篇
  1970年   380篇
  1969年   408篇
  1968年   489篇
  1967年   423篇
  1966年   423篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
The cyclic variation in the energy envelope of the speech signal results from the production of speech in syllables. This acoustic property is often identified as a source of information in the perception of syllable attributes, though spectral variation can also provide this information reliably. In the present study of the relative contributions of the energy and spectral envelopes in speech perception, we employed sinusoidal replicas of utterances, which permitted us to examine the roles of these acoustic properties in establishing or maintaining time-varying perceptual coherence. Three experiments were carried out to assess the independent perceptual effects of variation in sinusoidal amplitude and frequency, using sentence-length signals. In Experiment 1, we found that the fine grain of amplitude variation was not necessary for the perception of segmental and suprasegmental linguistic attributes; in Experiment 2, we found that amplitude was nonetheless effective in influencing syllable perception, and that in some circumstances it was crucial to segmental perception; in Experiment 3, we observed that coarse-grain amplitude variation, above all, proved to be extremely important in phonetic perception. We conclude that in perceiving sinusoidal replicas, the perceiver derives much from following the coherent pattern of frequency variation and gross signal energy, but probably derives rather little from tracking the precise details of the energy envelope. These findings encourage the view that the perceiver uses time-varying acoustic properties selectively in understanding speech.  相似文献   
992.
Certain theories of visual attention assume that at least one processing stage must be serial when the target of search is defined as the conjunction of two or more separable features. To explain why conjunction-search response times do not always form linearly increasing functions of display size, recent versions of this general model have posited the existence of an early parallel process that guides the serial stage toward display elements that are likely targets. Other models have relaxed the seriality assumption, allowing for a limited number of parallel decisions. In the three experiments reported here, a redundant-target detection task was used with conjunctively defined targets and display sizes of two (Experiment 1), one or two (Experiment 2), and six (Experiment 3). In all three experiments, strong evidence for parallel processing was observed. The implications for models of elementary visual processes are discussed.  相似文献   
993.
Traditional Dental Aptitude Test and academic grade point average have been shown to be poor predictors of clinical performance by dental students. To refine predictors of psychomotor skills, a wire-bending test was given to 105 freshmen at the beginning of their dental education. Grades from seven restorative preclinical courses in their freshman and sophomore years were compared to scores on wire bending and the three traditional predictors: GPA, academic aptitude, and perceptual aptitude scores. Wire-bending scores correlated significantly with six out of seven preclinical restorative courses. The predictive power for preclinical performance was doubled when wire bending was added to traditional predictors in stepwise multiple regression analysis. Wire-bending scores identified students of low performance. These preliminary results suggest that the wire-bending test shows some potential as a screening test for identifying students who may hae psychomotor difficulties, early in their dental education.  相似文献   
994.
The Test of Nonverbal Intelligence (TONI) and Wechsler Intelligence Scale for Children--Revised (WISC--R) were administered to 46 Native American and white students who were suspected by their classroom teachers of having learning handicaps. Pearson correlations between these sets of IQs ranged from .42 (TONI and WISC--R Performance) to .89 (WISC--R Verbal and Full Scale).  相似文献   
995.
Two studies examined the speed with which good spellers and poor spellers spell easy and difficult words. At both the elementary school (Grades 3 and 4) and undergraduate levels, good spellers spelled words more quickly than poor spellers. This difference appeared even for very easy words that all subjects could spell. Implications for the importance of automaticity in spelling competence are discussed.  相似文献   
996.
E L?chel 《Psyche》1990,44(9):826-847
The author presents different psychoanalytic conceptualizations of gender difference. She reviews the controversy between Freud and Jones and discusses in detail the views put forward by Montrelay, a student of Lacan, who relates early linguistic development to gender-specific differences in closeness between the child and the "mother's body".  相似文献   
997.
The power of moral ideas, here equated with superego strength, has been explained in increasingly complex terms over the course of the development of psychoanalysis. At first regarded mainly as useful in opposing oedipal instinctual demands, morality came to be seen also as opposed to aggressive wishes while at the same time capable of gratifying aggressive and libidinal forces. In this paper, I discuss the contribution to the strength of morality that comes from the effects of painful ("traumatic") experiences and from the use of moral ideas for social, adaptational purposes. In addition I consider the possibility that unchanging moral ideas can have changes in function in clinical work. A case is presented to illustrate these points.  相似文献   
998.
999.
Residents of a county nursing home underwent a forced, mass relocation. Gerontologists advised on preparation of staff and residents. No increase in residents' mortality or morbidity was found after the relocation. The highest death rate was in the anticipatory period, the year prior to the move.  相似文献   
1000.
Information search following damage to the frontal lobes   总被引:2,自引:0,他引:2  
Five adult patients with focal brain damage in different areas of the frontal lobes and five matched controls were administered a 20 Questions test. Other tests of planning, problem-solving, and decision-making were also administered to frontal lobe patients. The results indicate that damage to the frontal lobe impairs the ability to impose and utilize hierarchical organization in mental representation.  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