全文获取类型
收费全文 | 26973篇 |
免费 | 1167篇 |
国内免费 | 19篇 |
专业分类
28159篇 |
出版年
2023年 | 148篇 |
2021年 | 242篇 |
2020年 | 447篇 |
2019年 | 538篇 |
2018年 | 726篇 |
2017年 | 683篇 |
2016年 | 777篇 |
2015年 | 527篇 |
2014年 | 708篇 |
2013年 | 2969篇 |
2012年 | 1201篇 |
2011年 | 1245篇 |
2010年 | 833篇 |
2009年 | 857篇 |
2008年 | 1198篇 |
2007年 | 1160篇 |
2006年 | 1117篇 |
2005年 | 976篇 |
2004年 | 965篇 |
2003年 | 951篇 |
2002年 | 926篇 |
2001年 | 467篇 |
2000年 | 454篇 |
1999年 | 441篇 |
1998年 | 399篇 |
1997年 | 373篇 |
1996年 | 318篇 |
1995年 | 332篇 |
1994年 | 308篇 |
1993年 | 291篇 |
1992年 | 295篇 |
1991年 | 276篇 |
1990年 | 261篇 |
1989年 | 238篇 |
1988年 | 215篇 |
1987年 | 238篇 |
1986年 | 233篇 |
1985年 | 282篇 |
1984年 | 286篇 |
1983年 | 247篇 |
1982年 | 252篇 |
1981年 | 270篇 |
1980年 | 237篇 |
1979年 | 226篇 |
1978年 | 248篇 |
1977年 | 218篇 |
1976年 | 213篇 |
1975年 | 180篇 |
1974年 | 198篇 |
1973年 | 154篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
941.
942.
Regional cerebral glucose metabolism in aphemia: A case report 总被引:1,自引:0,他引:1
Michael Kushner Martin Reivich Abass Alavi Joel Greenberg Matt Stern Robert Dann 《Brain and language》1987,31(2):201-214
Local cerebral metabolism was determined in a patient suffering aphemia following cerebral infarction using the 18FDG-PET technique. The syndrome was characterized by profound ictal nonfluency with sparing of other language functions. Speech subsequently improved so that content and grammar were appropriate but mild dysprosody persisted. Conventional CT showed no lesion of the left hemisphere while PET revealed a discrete focus of hypometabolism on the left which partially resolved on serial studies. The metabolic lesion could be localized to the region of the inferior precentral gyrus and the adjacent subcortical space. 相似文献
943.
The relationship between the personality components of psychoticism, extraversion and neuroticism, and levels of conduct disorder, delinquency and therapy responsiveness in children is investigated. A series of studies reporting short- and long-term results test Eysenck's (1970) argument that extraverts, because of their lower levels of conditionability, should feature more prominently in groups showing higher levels of conduct disorder or delinquency. The extension of that argument to include the role of psychoticism (Eysenck H.J. and Eysenck S.B.G., Psychoticism as a Dimension of Personality, Hodder & Stoughton, London, 1976) is also subjected to experimental test. Two alternative conceptions of the part played by neuroticism, either that it acts as an amplifying device (high N) or as a filter against pressure to change (low N), are considered. The results support the importance of including personality factors in the study of antisocial behaviour in children. 相似文献
944.
945.
A series of experiments were undertaken to demonstrate the dominance advantage of a territorial resident over an intruder (the prior residence effect) in the adult male Convict Cichlid (Cichlasoma nigrofasciatum) and to evaluate the effects of alcohol (ethanol) on this phenomenon. After successfully demonstrating the prior residence effect, additional experiments were conducted in which the resident or intruder was given one of three different doses of ethanol (0.15%, 0.20%, 0.35%). These doses have previously been shown to reduce or increase intraspecific aggression in this species Over the entire dosage range, drugging the intruder produced no changes in the dominance advantage of the resident. However, drugging the resident at the higher doses (0.20%, 0.35%) resulted in loss of the resident's dominance advantage. These effects were not due to impaired locomotor behavior of the drugged fish, as no abnormal motor behaviors were noted. In general, as reported in previous studies, the resident fish, whether drugged or not, typically attacked first. Also as has been previously shown, the fish that attacked (bit) first typically showed eventual dominance. The present results show that the dominance advantage of the territorial resident is not altered by giving an intruder a hypo- or hyperaggression-producing dose of alcohol. Changes in the dominance advantage occur only as a function of drugging the resident, thereby providing evidence that the behavior of the territorial resident is either directly or indirectly (reaction of the intruder to these changes) responsible for the prior residence effect. The present studies also provide some pharmacological approaches for determining the variables important in a laboratory analog of a naturally occurring instance of intraspecific aggression. 相似文献
946.
Michael T. Christensen 《Aggressive behavior》1977,3(1):17-31
Genetically sterile male Norway rats, Rattus norvegicus, were tested in the laboratory to determine both 1) behavioral characteristics, and 2) the ability of sterile males to compete aggressively and sexually with wild Norway rat males. Sterile males were larger in weight, more frequently dominant, won as many fighting encounters, were as aggressive as wild males, and mounted females more frequently. Behavioral activities were similar for both strains when compared under laboratory conditions with no apparent abnormal behavior exhibited by the sterile males. Use of sterile males in biological control programs is discussed. 相似文献
947.
948.
David P. Kuna 《Journal of the history of the behavioral sciences》1976,12(4):347-353
As early as 1896, experimental psychologists began studying the mental proccesses involved in advertising. The first psychological theory of advertising maintained, in effect, that the consumer was a nonrational, suggestible creature under the hypnotic influence of the advertising copywriter. Walter Dill Scott was the major proponent of this theory, and it was largely through his writings that advertising men learned about the psychology of suggestion. Scott's theory was consistent with a growing trend in the advertising profession toward viewing consumer behavior as irrational. Scott's efforts might also be viewed as part of the trend in the advertising profession toward seeking a scientific basis for copywriting theory and practice. 相似文献
949.
950.