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   35526篇
  免费   690篇
  国内免费   3篇
  36219篇
  2019年   362篇
  2018年   562篇
  2017年   564篇
  2016年   583篇
  2015年   432篇
  2014年   524篇
  2013年   2510篇
  2012年   895篇
  2011年   983篇
  2010年   642篇
  2009年   577篇
  2008年   892篇
  2007年   812篇
  2006年   774篇
  2005年   659篇
  2004年   650篇
  2003年   621篇
  2002年   650篇
  2001年   1031篇
  2000年   994篇
  1999年   745篇
  1998年   355篇
  1997年   351篇
  1996年   355篇
  1992年   679篇
  1991年   645篇
  1990年   628篇
  1989年   600篇
  1988年   623篇
  1987年   558篇
  1986年   599篇
  1985年   580篇
  1984年   526篇
  1983年   437篇
  1982年   358篇
  1981年   353篇
  1979年   538篇
  1978年   414篇
  1977年   374篇
  1976年   370篇
  1975年   460篇
  1974年   573篇
  1973年   618篇
  1972年   485篇
  1971年   489篇
  1970年   441篇
  1969年   481篇
  1968年   601篇
  1967年   516篇
  1966年   540篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
212.
This study investigated the effect of EMG biofeedback training in reducing muscle tension among subjects who displayed Type A behavior. 22 Type A college students (19 to 22 yr. old) were randomly assigned to either a biofeedback group or a control group. After 6 wk. of training, Type A subjects showed a significant reduction in muscle tension for both resting and aroused states; however, the reduction of muscle tension did not result in reduction of Type A behavior patterns.  相似文献   
213.
9 stutterers and 9 nonstutterers were administered a dichotic digits test under conditions of free recall and directed attention. Analysis indicated right-ear preference for both groups and no differences between the free recall and directed listening conditions. Results are discussed in relation to previous studies in which dichotic digit-stimuli were presented to stutterers.  相似文献   
214.
In three experiments, subjects learned to classify dot patterns into three categories represented by either three, six, or nine exemplars. Following learning, subjects were tested on an additional set of patterns, which included patterns from the learning phase, the category objective prototypes, and new distortions of the objective prototypes. Also included in the test set were empirical prototypes and distortions of empirical prototypes. Empirical prototypes were derived by averaging feature values of category exemplars in the learning phase. The overall results revealed that empirical prototypes were classified more accurately than were objective prototypes. In addition, a pattern of convergence in error rates was observed for distortions of the objective and empirical prototypes as category set size increased, but this same pattern was not observed for the objective and empirical prototypes themselves. This lack of convergence for the prototypes is inconsistent with explanations of the category set size effect that rely on the central limit theorem.  相似文献   
215.
D. Scott in his paper [5] on the mathematical models for the Church-Curry -calculus proved the following theorem.A topological space X. is an absolute extensor for the category of all topological spaces iff a contraction of X. is a topological space of Scott's open sets in a continuous lattice.In this paper we prove a generalization of this theorem for the category of , -closure spaces. The main theorem says that, for some cardinal numbers , , absolute extensors for the category of , -closure spaces are exactly , -closure spaces of , -filters in , >-semidistributive lattices (Theorem 3.5).If = and = we obtain Scott's Theorem (Corollary 2.1). If = 0 and = we obtain a characterization of closure spaces of filters in a complete Heyting lattice (Corollary 3.4). If = 0 and = we obtain a characterization of closure space of all principial filters in a completely distributive complete lattice (Corollary 3.3).  相似文献   
216.
Truth and proof: The Platonism of mathematics   总被引:1,自引:0,他引:1  
W. W. Tait 《Synthese》1986,69(3):341-370
  相似文献   
217.
Functional measurement analyses and psychophysical techniques were used to assess how separate, cross-modal, aversive events are integrated in judgements of pain. Subjects made magnitude estimations of noxious stimuli produced by a 6 X 6 factorial design of electric shocks and loud tones. Group data and most of the individual results were consistent with a model of linear pain summation: The estimates of pain approximated the linear sum of the pain estimates of the individual electrocutaneous and auditory components. The relation between painful sensation and current intensity could be described by a mildly expansive power function with an exponent of about 1.1. Auditorily produced painful sensation related to sound pressure level by a mildly compressive power function with an exponent of about 0.90 as a representative figure. Results are interpreted in terms of a functional theory of pain. Noxious events are first transformed to psychological scale values via stimulus-specific psychophysical transfer functions. The outputs of these functions are then combined with other pain-related internal representations of either sensory or cognitive origin, according to simple algebraic models.  相似文献   
218.
Participants completed the Rotter internal/external (IE) instrument using three different response formats before and after completion of the Outward Bound program, and were evaluated by external observers at the end of the intervention. Multitrait-multimethod analyses indicated that five specific IE facets identified in previous research were consistently distinguished with each of the response formats. While responses were substantially more internal after the intervention, effect sizes varied with the IE facet and with the response format. Observer responses were significantly correlated with self-responses, and provided additional support for the construct validity of responses to the Rotter instrument and the interpretation of the intervention effect. Nevertheless, problems with the Rotter instrument were identified, and the implications for further research were discussed.  相似文献   
219.
Two basic assumptions of the Circumplex Model of family systems were evaluated: (1) Healthy families evidence balanced degrees of cohesion and adaptability, whereas problem families evidence extreme degrees, and (2) families with balanced degrees of cohesion and adaptability possess more positive communication skills than families with extreme degrees. Subjects were 58 mother-son dyads from father-absent families. In 29 of the families the adolescent was a juvenile offender, while in the remaining families there was no history of arrest or psychiatric referral. The dyads completed the Family Adaptability and Cohesion Scales (FACES) and an unrevealed differences interaction task. FACES was highly proficient at differentiating delinquent from nondelinquent families. Moreover, in families with balanced degrees of cohesion and adaptability, the mothers' communication was significantly more supportive and explicit, and the dyads evidenced significantly greater warmth and affection than dyads with extreme degrees.This research was supported by funding to the Department of Psychology at Memphis State University granted through the Centers of Excellence Program of the State of Tennessee. We thank the staff of the Memphis-Metro Youth Diversion Project for their consideration and assistance.  相似文献   
220.
Despite speculation that sucrose consumption affects behavior, little empirical information is available. Accordingly, this study investigated the effect of sucrose consumption on the behavior of eight preschool children. Children were tested individually using a double-blind, crossover design. On separate mornings each child received 6 ounces of juice, sweetened on one morning with sucrose and on the other with an artificial sweetener. Children were observed for 90 minutes following the drinks, alternating between 15-minute sessions of work on structured tasks and 15-minute sessions of free play. Following the sucrose drink the children showed a decrement in performance in the structured testing situation, and they demonstrated more inappropriate behavior during free play. These differences in behavior were most pronounced approximately 45 to 60 minutes after the drinks. Thus, the study provides objective evidence in young children of a rather subtle, yet significant, time-dependent behavior effect of sucrose ingestion.This research was funded in part by grants from the General Research Grants Committee, University Hospital, Boston University Medical Center, and from the University of Connecticut Research Foundation. The project was conducted at the Clinical Research Center, Massachusetts Institute of Technology (National Institute of Health/General Clinical Research Center Grant 5M01-RR00088-20). We would like to express our appreciation to the many staff members of the Clinical Research Center for their extensive cooperation in helping us to plan and carry out this study, and to the director and staff of Technology Children's Center for their assistance in helping us to reach interested families. We also would like to thank the parents and children who participated in the study. Portions of this paper were presented at the annual meeting of the American Psychological Association, Toronto, August 1984.  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