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   59321篇
  免费   1550篇
  国内免费   12篇
  2019年   466篇
  2018年   3994篇
  2017年   3296篇
  2016年   2837篇
  2015年   701篇
  2014年   702篇
  2013年   3932篇
  2012年   1564篇
  2011年   3374篇
  2010年   3097篇
  2009年   2087篇
  2008年   2656篇
  2007年   3010篇
  2006年   873篇
  2005年   928篇
  2004年   875篇
  2003年   819篇
  2002年   742篇
  2001年   1251篇
  2000年   1235篇
  1999年   936篇
  1998年   433篇
  1996年   548篇
  1995年   496篇
  1994年   492篇
  1993年   461篇
  1992年   934篇
  1991年   825篇
  1990年   842篇
  1989年   730篇
  1988年   742篇
  1987年   719篇
  1986年   708篇
  1985年   705篇
  1984年   628篇
  1983年   518篇
  1981年   422篇
  1979年   601篇
  1978年   443篇
  1976年   411篇
  1975年   554篇
  1974年   535篇
  1973年   602篇
  1972年   573篇
  1971年   517篇
  1970年   452篇
  1969年   431篇
  1968年   553篇
  1967年   464篇
  1966年   453篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
Representation of linear orders   总被引:1,自引:0,他引:1  
Two binary classification tasks were used to explore the associative structure of linear orders. In Experiment 1, college students classified English letters as targets or nontargets, the targets being consecutive letters of the alphabet. The time to reject nontargets was a decreasing function of the distance from the target set, suggesting response interference mediated by automatic associations from the target to the nontarget letters. The way in which this interference effect depended on the placement of the boundaries between the target and nontarget sets revealed the relative strengths of individual interletter associations. In Experiment 2, students were assigned novel linear orders composed of letterlike symbols and asked to classify pairs of symbols as being adjacent or nonadjacent in the assigned sequence. Reaction time was found to be a joint function of the distance between any pair of symbols and the relative positions of those symbols within the sequence. The effects of both distance and position decreased systematically over 6 days of practice with a particular order, beginning at a level typical of unfamiliar orders and converging on a level characteristic of familiar orders such as letters and digits. These results provide an empirical unification of two previously disparate sets of findings in the literature on linear orders, those concerning familiar and unfamiliar orders, and the systematic transition between the two patterns of results suggests the gradual integration of a new associative structure.  相似文献   
922.
Detection versus discrimination of visual orientation   总被引:4,自引:0,他引:4  
D Sagi  B Julesz 《Perception》1984,13(5):619-628
The role of focused attention in vision is examined. Recent theories of attention hypothesize that serial search by focal attention is required for discrimination between different combinations of features. Experiments are reported which show that the mixture of a few (less than five) horizontal and vertical line segments embedded in an aggregate of diagonal line segments can be rapidly counted (also called 'subitizing') by a parallel (preattentive) process, while the discrimination between horizontal and vertical orientation requires serial search by shifting focal attention to each line segment. Thus detecting and counting targets that differ in orientation can be done in parallel by a preattentive process, whereas knowing 'what' the orientation of a target is (horizontal or vertical, ie of a single conspicuous feature) requires a serial search by focal attention.  相似文献   
923.
Studies were made of rapid error correction movements in eight subjects performing a visually guided tracking task involving flexion-extension movements about the elbow. Subjects were required to minimize reaction times in this two-choice task. Errors in initial movement direction occurred in about 3% of the trials. Error correction times (time from initiation to reversal of movement in incorrect direction) ranged from 30-150 ms. The first sing of correction of the error movement was a suppression of the electromyographic (EMG) activity in the muscle producing the error movement. This suppression started as early as 20-40 ms after the initiation of the error-related EMG activity and as much as 50 ms before any overt sign of limb movement. The correction of the error movement was also accompanied by an increase in the drive to the muscle which moved the arm in the correct direction. This increased activity always occurred after the initiation of the error movement. it is concluded that the first step in the error correction, suppression of drive to the muscle producing the error movement, cannot be based on information from the moving limb. It is thus suggested that this earliest response to the error movement is based on central monitoring of the commands for movement.  相似文献   
924.
Sixteen stories were read to children at ages 4, 7, and 11 years and to college freshmen (n = 24 per age level) to investigate the effects of recency and specific story content on the development of moral reasoning. The stories consisted of either positive or negative intention and either positive or negative consequence in one of four situations: rule breaking, property damage, property damage with peer interaction, or injury to a person. At each age level, half of the subjects heard the stories with the intention first and the consequence second, and half heard them in the reverse order. Analyses confirmed that in general younger children judged on consequence, whereas older children utilized intention, and that on stories containing intentional injury to a person, the younger child took intention into account. Recency effects were evidenced for both the 4- and 7-year-olds. In the 4-year-old group, however, the recency effects failed to override the salience of negative consequence in contexts of positive intention and negative consequence. This suggests that preschool children may respond primarily to the negative aspect of the story, whether intention or consequence.  相似文献   
925.
The self-injurious forehead-gouging behavior that had resulted in blindness for a profoundly retarded 27-yr-old male was successfully treated using a combination of differential reinforcement of incompatible behavior during unstructured situations and prevention of escape during compliance situations. After self-injurious behavior was reduced to a low frequency, a reduction of his daily dose of chloral hydrate was accompanied by a large increase in self-injury, but the behavior gradually returned to its previous low level. A large increase in self-injury also occurred following transfer to another living unit, but the behavior again decreased to a low frequency. Treatment gains were maintained following transfer to another residential facility with follow-up observations occurring at 1, 2, 8, 15, 22, 27 and 35 months. The multiple determination of self-injurious behavior in this one S highlights the behavioral complexity of some of these behaviors.  相似文献   
926.
Research is reviewed which suggests that hyperventilation syndrome is an underdiagnosed disorder for the presentation of many patients experiencing apparent anxiety states. In a test of this hypothesis, 21 normal individuals (9 female) underwent a 2 min period of intentional hyperventilation following a 10 min baseline phase. Hyperventilation was accompanied by increased subjective anxiety and tachycardia, and indications of peripheral vasoconstriction. Following hyperventilation, Ss experienced increased levels of state anxiety and perceived autonomic arousal, as indexed by self-report instruments. These results support the hypothesis that undiagnosed hyperventilatory phenomena may be etiologically implicated in states of pathologic anxiety.  相似文献   
927.
The five stages of family development and their phase-specific tasks as delineated by Michael A. Solomon in an article that appeared in this journal (1973) are given dramatic representation by Virginia Woolf in her novel To the Lighthouse (1927). The novel begins with the Ramsay family system arrested at the third stage of development; and it is only after the death of Mrs. Ramsay that the remaining family members begin to attend to the phase-specific tasks of stages four and five, and family development commences.  相似文献   
928.
JÜRG WILLI  M.D. 《Family process》1984,23(2):177-185
The author presents some new theoretical aspects and therapeutic implications of the concept of Couples in Collusion, (22), first published in 1975. According to this concept, the emotional attraction in the selection of a mate is based on a fascinating, mutual, and alarming theme, shared by both partners in order to be mastered together. The partners unavowedly start colluding to compensate for former frustrations and to repress fears of intimacy. After some time of living together and in defense of repressed feelings, they may enter into an escalation of the dysfunctional interactional pattern. Experience shows that severely neurotic personalities don't necessarily start colluding, provided that their partners don't gratify regressive needs or reinforce their defenses but help to cope with the frustrations of these unfulfilled regressive wishes. Therapies based on the concept of collusion aim at the improvement of intradyadic and extradyadic boundaries and the depolarization of extreme progressive-regressive behavior. These goals can be reached by both systemic and psychodynamic techniques. The concept of collusion may serve as a guide for this therapeutic process.  相似文献   
929.
930.
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