全文获取类型
收费全文 | 83232篇 |
免费 | 3060篇 |
国内免费 | 28篇 |
出版年
2019年 | 941篇 |
2018年 | 1332篇 |
2017年 | 1382篇 |
2016年 | 1558篇 |
2015年 | 1122篇 |
2014年 | 1221篇 |
2013年 | 5890篇 |
2012年 | 2441篇 |
2011年 | 2618篇 |
2010年 | 1507篇 |
2009年 | 1512篇 |
2008年 | 2194篇 |
2007年 | 2151篇 |
2006年 | 1970篇 |
2005年 | 2900篇 |
2004年 | 2205篇 |
2003年 | 1919篇 |
2002年 | 1781篇 |
2001年 | 2457篇 |
2000年 | 2405篇 |
1999年 | 1801篇 |
1998年 | 884篇 |
1997年 | 806篇 |
1996年 | 787篇 |
1992年 | 1586篇 |
1991年 | 1510篇 |
1990年 | 1488篇 |
1989年 | 1388篇 |
1988年 | 1325篇 |
1987年 | 1294篇 |
1986年 | 1389篇 |
1985年 | 1419篇 |
1984年 | 1199篇 |
1983年 | 1076篇 |
1982年 | 780篇 |
1981年 | 816篇 |
1979年 | 1271篇 |
1978年 | 933篇 |
1977年 | 762篇 |
1976年 | 750篇 |
1975年 | 1096篇 |
1974年 | 1196篇 |
1973年 | 1299篇 |
1972年 | 1112篇 |
1971年 | 1034篇 |
1970年 | 953篇 |
1969年 | 992篇 |
1968年 | 1250篇 |
1967年 | 1163篇 |
1966年 | 1024篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
Direction- and velocity-specific responses from beyond the classical receptive field in the middle temporal visual area (MT) 总被引:7,自引:0,他引:7
The true receptive field of more than 90% of neurons in the middle temporal visual area (MT) extends well beyond the classical receptive field (crf), as mapped with conventional bar or spot stimuli, and includes a surrounding region that is 50 to 100 times the area of the crf. These extensive surrounds are demonstrated by simultaneously stimulating the crf and the surround with moving stimuli. The surrounds commonly have directional and velocity-selective influences that are antagonistic to the response from the crf. The crfs of MT neurons are organized in a topographic representation of the visual field. Thus MT neurons are embedded in an orderly visuotopic array, but are capable of integrating local stimulus conditions within a global context. The extensive surrounds of MT neurons may be involved in figure-ground discrimination, preattentive vision, perceptual constancies, and depth perception through motion cues. 相似文献
942.
The present study examined the effects of the sex of the leader, the sex of the rater, and the temporal position of leader performance information on ratings of leader behavior. Male and female subjects listened to an audiotape of a male or female leader and then rated the leader's initiating structure and consideration behaviors. The position of the leader performance information was manipulated by describing the leader as successful before or after raters listened to the audiotape or not presenting raters with the performance information. Analyses indicated that the sex of the leader and/or sex of the rater biased ratings of initiating structure when the performance information was presented after the audiotape and when no leader performance information was presented. Consideration ratings were affected only by the position of the leader performance information. The results are interpreted within a cognitive/implicit sex theory framework. Implications for leadership research are also discussed.Portions of the data analyzed in this study were collected by the second author as part of a master's thesis directed by Joseph A. Sgro. 相似文献
943.
944.
The purpose of this study was to examine the attitudes of a general population toward female participation in sports and to replicate a previous study. The two areas investigated were (1) the perception of enhancement or detraction of femininity by girls' participation in athletics, and (2) whether different sports elicited different attitudes towards female participation in athletics. A town in Iowa was sampled. The results indicated that, in general, participation in sports neither detracted from nor enhanced femininity. Furthermore, most of the people wanted their daughters to play basketball, even though it neither detracted from nor enhanced femininity. The data suggest that traditional, rigid sex-role stereotypes were transcended and the opportunity set was dominant.This study was partially funded by a grant from the University of Iowa Graduate School. Appreciation is expressed to Dr. Eldon Snyder for graciously sharing his instrument and recent work. 相似文献
945.
Peter J. Furnell 《British Journal of Guidance & Counselling》1985,13(3):248-265
A case-study of gay identity development is presented based on Kelly's personal construct theory. The subject is a married man in his early thirties. Repertory grid technique is used to investigate the subject's construing of his relationships with gay men, and Kelly's account of emotion in terms of constructs of transition is used in analysing the emotional dimensions of the subject's experience. Three dimensions of interpersonal construing emerged from the grid analysis: emotional impact, negative affect and friendship. Five aspects of the subject's emotional experience are discussed: aggression, threat, anxiety, hostility and guilt. Some implications of the study for counselling are outlined, its limitations noted, and possible avenues for further research identified. It is argued that the study serves to illustrate the value of Kelly's perspective in understanding the interpersonal and emotional dimensions of gay identity development. 相似文献
946.
Brian J. Thorne 《British Journal of Guidance & Counselling》1985,13(1):22-34
The publication in 1973 of Student Counselling in Practice signalled a new phase in the development of both careers and counselling services in the tertiary sector. The emergence of the professional careers adviser in higher education is described alongside the key role of the Association of Graduate Careers Advisory Services. The gradual professionalisation of student counselling is shown to have taken a different form, as a result of the policies of the Association for Student Counselling with its insistence on role definition and the accreditation of practitioners. Developments in further education are briefly reviewed, and a final section considers the present situation and possible future trends. 相似文献
947.
Alternation behavior, spatial discrimination, and reversal disturbances following 6-hydroxydopamine lesions in the nucleus accumbens of the rat 总被引:3,自引:0,他引:3
K Taghzouti A Louilot J P Herman M Le Moal H Simon 《Behavioral and neural biology》1985,44(3):354-363
The effects of dopaminergic depletion of the nucleus accumbens was tested in various behavioral tasks such as alternation, spatial discrimination, and reversal learning, and in an extinction paradigm in a T maze. Animals with lesions showed impairment of spontaneous alternation behavior, disturbances in the acquisition of spatial discrimination, and great difficulty in reversing previously learned habits. In the extinction phase, experimental animals are unable to adjust their behavior, and continue to choose the previously reinforced arm of the T maze. It is suggested that the nucleus accumbens plays an important role in the transition of motivation into action, and that dopamine has a facilitatory influence on the mediation of these processes. 相似文献
948.
During 46 consecutive days the daily food intake and weight were recorded in 16 male Wistar rats. On Days 31-45 one mouse was presented each rat daily. Before any experience with mice (Days 0-27) the mousekiller rats, compared with the nonkiller rats, regulated their individual food intake more closely to their homeostatic equilibria, corrected for the linear trend. This result indicates a functional difference in food intake regulation between mousekiller rats and nonkiller rats prior to any experience with mice. However, no difference in the mean food intake was found between the mousekiller and the nonkiller rats. 相似文献
949.
Aggressive behavior inhibition by serotonin and quipazine injected into the amygdala in the rat 总被引:1,自引:0,他引:1
The effects on aggressive behavior, open-field activity, and pain threshold of bilateral microinjections of serotonin (20 micrograms) and quipazine (20 micrograms), the direct serotonergic receptor agonist, into the cortico-medial amygdala were investigated in Wistar rats. Both drugs significantly prolonged the attack latency in isolated killer rats (predatory aggression model), and suppressed the incidence of aggressive postures/attacks in shock-induced fighting test (affective aggression). The only difference in the open-field behavior was the lower number of central square entries in drug-treated compared to saline-injected rats. None of the substances produced any significant change in jump threshold. It is concluded that stimulation of serotonin receptors within the amygdala produces inhibition of affective and muricidal behavior in isolated rats. The effect does not seem to be dependent on changes in general activity and pain sensitivity. 相似文献
950.
Individual differences in attribution have been little researched. Beliefs about locus of control have been taken to be stable and important differences between people. They may provide some of the background assumptions on which people base their explanations of actions, especially insofar as these explanations imply that the cause of an action was within the agent or his environment, and that the action was or was not under the agent's control. Respondents were therefore asked to fill in Rotter and Levenson locus of control questionnaires and to provide explanations or ask questions about several actions. It was hypothesized that internals would be inclined to go for explanations which were personal and implied high control, while externals would not. However, what emerged was the paradoxical finding that internals provided explanations which implied that the causes of the actions lay outside the agent, while externals provided ones which implied that the causes lay within. This result is discussed in terms of the difference between actions and outcomes, and the possibility that an important difference between people may be in the rigidity and simplicity of their beliefs about causality. 相似文献