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   7123篇
  免费   414篇
  国内免费   2篇
  7539篇
  2021年   59篇
  2020年   124篇
  2019年   140篇
  2018年   181篇
  2017年   239篇
  2016年   230篇
  2015年   164篇
  2014年   196篇
  2013年   811篇
  2012年   336篇
  2011年   350篇
  2010年   224篇
  2009年   231篇
  2008年   286篇
  2007年   306篇
  2006年   256篇
  2005年   257篇
  2004年   235篇
  2003年   221篇
  2002年   244篇
  2001年   114篇
  2000年   123篇
  1999年   118篇
  1998年   100篇
  1997年   88篇
  1996年   106篇
  1995年   93篇
  1994年   84篇
  1993年   72篇
  1992年   91篇
  1991年   70篇
  1990年   60篇
  1989年   59篇
  1988年   57篇
  1987年   56篇
  1986年   59篇
  1985年   72篇
  1984年   77篇
  1983年   55篇
  1982年   76篇
  1981年   78篇
  1980年   61篇
  1979年   59篇
  1978年   48篇
  1977年   85篇
  1976年   50篇
  1975年   55篇
  1974年   54篇
  1973年   52篇
  1972年   48篇
排序方式: 共有7539条查询结果,搜索用时 31 毫秒
191.
Mental rotation in the congenitally blind was investigated with a haptic letter-judgment task. Blind subjects and blindfolded, sighted subjects were presented a letter in some orientation between 0° to 300° from upright and timed while they judged whether it was a normal or mirror-image letter. Both groups showed an increasing response time with the stimulus’s departure from upright; this result was interpreted as reflecting the process of mental rotation. The results for the blind subjects suggest that mental rotation can operate on a spatial representation that does not have any specifically visual components. Further research showed that for the sighted subjects in the haptic task, the orientation of a letter is coded with respect to the position of the hand. Sighted subjects may code the orientation of the letter and then translate this code into a visual representation, or they may use a spatial representation that is not specifically visual.  相似文献   
192.
The present experiments examined the role of imagery ability in recall of either the terminal location or the distance of a preselected horizontal linear movement following changes in the recall starting position. Subjects were selected on the basis of their scores on a shortened version of the Betts Questionnaire upon Mental Imagery (Betts Q.M.I., Sheehan 1967). Both high and low imagers were assigned to one of four groups, HIL, LIL, HID, LID, the last letter indicating the movement cue (terminal location or distance moved) to be recalled. Recall of the appropriate movement cue from one of four new recall starting positions occurred after either a 5-sec or 30-sec unfilled retention interval. Analysis of constant error indicated all groups were unable to recall the specified movement cue independent of the other source of information, even when subjects were given explicit instructions to utilise an imagery strategy. The data corroborate our earlier findings that memory for self paced movements is based on an interaction of location and distance cues derived from the criterion movement.  相似文献   
193.
Review of the literature revealed two family theories of psychosomatic illness: the ‘enmeshed’ family of Minuchin and the family with affect disturbances. We interviewed twelve families, each containing a child with eczema. Most, but not all, of the families do fit in with one or other or both of the proposed interactional patterns, but the theory of a single family type, the ‘psychosomatogenic family’, is not supported. This complements the studies of individuals where specificity hypotheses have proved oversimplified.  相似文献   
194.
Do vowel-contingent selective adaptation effects for place of articulation depend on vowel identity, or on the particular formant frequencies used? An experiment is reported here which tested the adaptation effects of consonants with exactly the same formant transitions before different diphthongs. In this experiment, the phonetic identity of the vowel and the formant frequencies of the consonant are not confounded as they have been in previous studies. In the contingent adaptation condition, no phoneme boundary shifts were observed, and this is interpreted along with previous evidencefor such phoneme boundary shifts when phonetic identity of the vowel and formant frequencies are confounded as indicating that adaptation operates on the spectral representation of the stimulus. Other evidence consistent with this conclusion is that adaptation with alternating adaptors from each end of the test series produced negligible shifts, and that a single adaptor from a diphthong series different from that of the test series produced phoneme boundary shifts as large as those with a single adaptor from the same test series.  相似文献   
195.
Several authors have identified sets of axioms for a preference relation ? on a two-factor set A × X which imply that ? can be represented by specific types of numerical structures. Perhaps the two best-known of these are the additive representation, for which there are real valued functions fA on A and fX on X such that (a, x) ? (b, y) if and only if fA(a) + fX(x) > fA(b) + fX(y), and the lexicographic representation which, with A as the dominant factor, has (a, x) ? (b, y) if and only if fA(a) > fA(b) or {fA(a) = fA(b) and fX(x) > fX(y)}. Recently, Duncan Luce has combined the additive and lexicographic notions in a model for which A is the dominant factor if the difference between a and b is sufficiently large but which adheres to the additive representation when the difference between a and b lies within what might be referred to as a lexicographic threshold. The present paper specifies axioms for ? which lead to a numerical model which also has a lexicographic component but whose local tradeoff structure is governed by the additive-difference model instead of the additive model. Although the additive-difference model includes the additive model as a special case, the new lexicographic additive-difference model is not more general than Luce's model since the former has a “constant” lexicographic threshold whereas Luce's model has a “variable” lexicographic threshold. Realizations of the new model range from the completely lexicographic representation to the regular additive-difference model with no genuine lexicographic component. Axioms for the latter model are obtained from the general axioms with one slight modification.  相似文献   
196.
Intervals and tenses   总被引:1,自引:0,他引:1  
Concluding Remarks Neither question (1) nor question (2) posed on page 446 have been adequately answered in this paper. Regarding (1) we have merely given functor maps onto the object languages of physical theories and regarding (2) we have merely described the algebraic structure of observables. A more satisfactory treatment will most likely involve (1) a generalization to algebraic categories, universal algebra and model theory in such a way as to capture the full inference structure of (perhaps van Fraassen's modal) quantum logic, and (2) the introduction of the category of differentiable manifolds in order to capture the full symplectic structure of (perhaps Chernoff-Marsden's) Hamiltonian dynamics. (See van Fraassen [4] and Chernoff-Marsden [5] in Other References.)Finally, the intriguing suggestion of Finkelstein that category theory is to metaphysics what group theory is to physics deserves serious consideration. Indeed, although the theme has not been touched on explicitly in this paper it was central in motivating the project initially. However, it is more properly to be developed in a context external to a symposium on quantum logic.  相似文献   
197.
Sixty-five men and women, aged 50 to 88 years, completed Holland's Vocational Preference Inventory (VPI) and a work history questionnaire. Each participant was assigned one-letter Holland personality type codes for his or her first full-time job, longest full-time job, last job (if retired) or present job (if employed), and hobbies. In general, VPI scale scores and high point codes were consistent with the occupational codes but less consistent with the hobby code. The usefulness of Holland's vocational theory to the aged population is discussed.  相似文献   
198.
It has been consistently reported the deaf children have tremendous problems in reading English sentences. Three experiments were conducted in the present study to investigate the nature of deaf children's reading inability. The first experiment looked into the letter-decoding process. It was found that deaf subjects took longer than normal-hearing subjects in encoding and decoding alphabetic letters. The second experiment employed a sentence-picture verification paradigm. The results showed that deaf subjects adopted a visual-imagery coding strategy rather than a general linguistic coding strategy as described by H. H. Clark and W. Chase (Cognitive Psychology, 1972, 3, 472–517) and by P. A. Carpenter and M. A. Just (Memory and Cognition, 1975, 3, 465–473). However, when the sentence was presented in manual signs (Experiment 3), deaf subjects' verification time showed that they adopted a general linguistic coding strategy. Thus, deaf subjects are capable of linguistic coding strategy, but they do not apply it to process printed English sentences. A second-language hypothesis was advanced to account for the obtained data. Deaf children's reading inability was also discussed from this perspective.  相似文献   
199.
Traditional residential care environments for the elderly have been criticized because of the observed low levels of residents' engagement. Behavioural models of depression suggest an inverse relationship between engagement in pleasant activities and depression. The present study examined the relationship between depression and engagement in the residents of a home for the elderly. Correlational analyses indicated no relationship between level of depression and level of engagement but an association was found between level of depression and engagement in activities subjectively most enjoyed. There was considerable variation in the residents' perception of their behaviour; some residents viewed active engagement negatively whilst clearly enjoying behaviour that is technically disengaged. It is suggested that the results of the study emphasize the importance both of individual differences in behaviour and of covert behaviour. Implications for the engagement concept are discussed. In particular it is suggested that programmes in care environments aimed at increasing engagement in order to enhance the quality of life should focus more on the individual and on his perception of his behaviour.  相似文献   
200.
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