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   21202篇
  免费   42篇
  21244篇
  2024年   3篇
  2023年   9篇
  2022年   4篇
  2021年   11篇
  2020年   24篇
  2019年   33篇
  2018年   3507篇
  2017年   2836篇
  2016年   2277篇
  2015年   220篇
  2014年   105篇
  2013年   184篇
  2012年   606篇
  2011年   2434篇
  2010年   2537篇
  2009年   1496篇
  2008年   1727篇
  2007年   2221篇
  2006年   58篇
  2005年   241篇
  2004年   192篇
  2003年   138篇
  2002年   74篇
  2001年   39篇
  2000年   64篇
  1999年   18篇
  1998年   35篇
  1997年   18篇
  1996年   13篇
  1995年   5篇
  1994年   5篇
  1992年   10篇
  1991年   4篇
  1990年   11篇
  1989年   5篇
  1988年   8篇
  1987年   5篇
  1985年   3篇
  1983年   3篇
  1982年   6篇
  1981年   3篇
  1980年   4篇
  1978年   4篇
  1976年   5篇
  1975年   3篇
  1974年   3篇
  1973年   9篇
  1972年   3篇
  1969年   4篇
  1967年   2篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
The essay examines the argument advanced by E.D. Hirsch, Jr., for instituting ‘cultural literacy’ as a fundamental priority of schools. A number of confusions and equivocations in Hirsch's reasoning are identified, and the propensity of his project to indoctrinate is exposed. Among the features of Hirsch's argument shown to be troubling are his shifting construal of ‘language’, his inconsistency about the requirements of cultural literacy, and his uncritical relation to traditional images of the American past and present. The upshot is to raise the question why Hirsch's project has elicited wide support and praise.  相似文献   
22.
23.
How can we explain that an assertion on something perceived can be understood in the same manner by somebody who cannot perceive that scene? This problem bases the interest in computational linguistics in how listener modeling could possibly be harmonized with reference semantics. Mental images substituting real perception appear as a way out. The architecture of the listener model has to be adapted to the creation and use of such pictorial data structures. Furthermore, the relation between the latter and a verbal (i. e., propositional) representation must be understood. The resulting architecture of a listener model with reference semantics can be employed to solve communicational problems from three general classes in a better way, as is demonstrated by an example implementation.  相似文献   
24.
Two questions were addressed in the present study: (1) Do autistic and normally developing children exhibit regionally specific differences in electroencephalographic (EEG) activity? (2) Do subgroups of autistic children classified according to Wing and Gould's (1979) system which emphasizes degree of social impairment exhibit distinct patterns of EEG activity? Twenty-eight children with autism (5 to 18 years of age) and two groups of normally developing children (one matched on chronological age and the other on receptive language level) participated. EEG was recorded from left and right frontal, temporal, and parietal regions during an alert baseline condition. Compared to normally developing children, autistic children exhibited reduced EEG power in the frontal and temporal regions, but not in the parietal region. Differences were more prominent in the left than the right hemisphere. Furthermore, subgroups of autistic children based on Wing and Gould's system displayed distinct patterns of brain activity. Compared to autistic children classified as “active-but-odd,” “passive” autistic children displayed reduced alpha EEG power in the frontal region.  相似文献   
25.
26.
In light of information uncovered about human radiation experiments conducted during the Cold War, an important charge for the Advisory Committee on Human Radiation Experiments was to assess the current state of protections for human research subjects. This assessment was designed to enhance the Committee's ability to make informed recommendations for the improvement of future policies and practices for the protection of research subjects. The Committee's examination of current protections revealed great improvement over those from the past, yet some problems remain. Although the data collected by the Committee highlight specific areas in need of attention, the Committee's work should be viewed in part as the beginning of a series of ongoing assessments of the adequacy and effectiveness of the protections afforded to human subjects.  相似文献   
27.
The present studies investigated the relationship between prepulse effects on the modification of the brainstem startle reflex and magnitude estimates of startle-eliciting stimuli. In Experiment 1, startle eyeblink responses were elicited in 24 students, half of whom were instructed to estimate the loudness of the startle stimulus (actual intensities of 80, 90, and 100 dB) and half of whom were instructed to estimate the magnitude of their eyeblink. When weak acoustic prepulses preceded the startle-eliciting stimulus, eyeblink amplitude was inhibited, and estimates of response magnitude decreased, but estimates of startle stimulus magnitude decreased only when 100-dB startle stimuli were presented. In Experiment 2, the same startle stimuli were preceded on some trials by a vibrotactile prepulse to the hand. In conditions in which startle amplitude was inhibited, startle stimulus magnitude estimates were not affected. This suggests that the effect of acoustic prepulses on 100-dB startle stimuli in Experiment 1 may have been due to loudness assimilation, an effect independent of the prepulse inhibition of startle responding.  相似文献   
28.
Twenty-nine infants exposed in utero to methadone and 37 comparison infants were examined on the Neonatal Behavioral Assessment Scale at early and late neonatal ages. All infants were full-term at birth, over 2500 g, and not yet circumcised at the early assessment. None of the methadone-exposed infants were breast-fed or were being treated pharmacologically for withdrawal. During the first week of life, methadone-exposed neonates differed from comparison ones in motoric behavior. Relative to comparison-group infants, they were jerkier and more tremulous, tense, active, and better able to put hand in mouth. By the end of the first month these differences diminished, although there was still a tendency for the methadone-exposed infants to have elevated body tonus. Neither perinatal complications, birth weight, nor sex of infant could explain the early neonatal differences between the methadone and comparison groups. Past the early stage of acute withdrawal, neonates exposed prenatally to methadone behave not unlike their nonexposed peers.  相似文献   
29.
30.
Apparent volume for geometric solids and life-sized two dimensional representations of these solids was scaled by magnitude estimation. Data were adequately fit by power functions whose exponents were less than those previously reported for judgments of apparent length and area. Object shape and mode of presentation affected both magnitude estimations of apparent volume and the best fitting power function exponents. The influence of shape, both across object shape classes and within the cylinder shape class, appears to depend upon the relative elongation of the vertical dimension.  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