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   46825篇
  免费   1921篇
  国内免费   18篇
  2020年   543篇
  2019年   670篇
  2018年   942篇
  2017年   986篇
  2016年   1015篇
  2015年   702篇
  2014年   853篇
  2013年   3612篇
  2012年   1536篇
  2011年   1551篇
  2010年   994篇
  2009年   926篇
  2008年   1387篇
  2007年   1373篇
  2006年   1223篇
  2005年   1084篇
  2004年   1012篇
  2003年   953篇
  2002年   985篇
  2001年   1497篇
  2000年   1429篇
  1999年   1076篇
  1998年   467篇
  1997年   448篇
  1996年   425篇
  1995年   433篇
  1992年   905篇
  1991年   832篇
  1990年   874篇
  1989年   775篇
  1988年   810篇
  1987年   748篇
  1986年   754篇
  1985年   692篇
  1984年   647篇
  1983年   578篇
  1982年   453篇
  1979年   693篇
  1978年   483篇
  1977年   429篇
  1975年   576篇
  1974年   630篇
  1973年   680篇
  1972年   528篇
  1971年   511篇
  1970年   455篇
  1969年   518篇
  1968年   620篇
  1967年   544篇
  1966年   477篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
951.
952.
Twenty-two people who were presidential assassins and other similarly dangerous persons were assessed from information contained in Secret Service files and in published accounts. These documents were studied in order to determine common characteristics as well as other clues to the identification of potentially dangerous persons. Although there was no single pattern of development, there was a pattern of maladjustment that embraced common feelings of inadequacy or persecution, which led to similar patterns of behavior when attempting to resolve frustration. In practical terms, these profiles show:
  • 1 A systematic pattern of inadequacy in dealing with social, intellectual, and vocational challenges.
  • 2 A corresponding absence of any positive channel for achieving satisfaction or a sense of accomplishment.
In uniquely personal ways, each of these chronically frustrated individuals came to view his or her target either as the personification of the oppressive system, or as the agent through whom he or she could achieve “one great act,” or otherwise gain instant attention and status.  相似文献   
953.
Murray L. Wax 《Zygon》1984,19(1):5-20
Abstract. The English term religion is used to refer to local Christian churches, their organizations, and their practices. Nevertheless, Western anthropologists have tried to utilize it as if it were a technical term with universal applicability. Anthropologists have sought to characterize religion by several dichotomies, although their own field researches have revealed the irrelevance of such dichotomies as well as the fact that non-Western peoples do not recognize an entity equivalent to religion. Were the characteristics used by anthropologists in defining religion precisely applied to Western societies, then several other kinds of organizations, ceremonials, and practices would have as much, or even greater, claim to being included within the rubric of religion as the Christian and allied churches. The consequence of this conceptual imprecision has been the theoretical stagnation noted by eminent theorists.  相似文献   
954.
Postpartum and lactational estrus: a comparative analysis in rodentia   总被引:1,自引:0,他引:1  
Virgin rodents exhibiting cycling estrus have traditionally been used for comparative studies of reproductive behavior. However estrus occurs in other life-history contexts, some of which differ from cycling estrus (CE) in that (a) the female is disposed to behave both maternally and sexually and (b) they result in litter overlap (i.e., the simultaneous gestation and lactation of two litters). In this report, two of these other modes of estrus are examined, with emphasis on their evolutionary and ecological implications. By means of a literature search of the order Rodentia, postpartum estrus (PPE) and lactational estrus (LE) were documented in 15 families, 71 genera, and 141 species. Analysis of these data showed that PPE and LE were nonrandomly distributed across taxa. They were statistically overrepresented in the family Cricetidae and underrepresented in squirrels (Sciuridae) and in pocket mice and kangaroo rats (Heteromyidae). Analysis of the phenotypes by which PPE and LE are achieved suggests important differences between them and CE in several parameters of female reproductive effort and breeding strategy, including maternal and copulatory behavior, optimal timing of litters, and hormonal control of heat and lactation.  相似文献   
955.
956.
The traditional concept of belief is analyzed and compared with a behavior analytic concept of belief. Beliefs and belief statements are differentiated and relationships between them are examined. The often troublesome inconsistencies in people's beliefs are examined in general and explained, including the phenomena of compartmentalization and repression. Social implications are pursued relative to both punishment for inconsistency in belief and counter-controls thwarting such punishment. The role of teachers in shaping beliefs is analyzed, and appropriate teaching strategies are reviewed.  相似文献   
957.
The author focuses on the trend in the family therapy field toward an expanded view of families in the context of their social environments. Within this broader eco-system perspective attention is given to individual-family-social network interrelations with implications for the family therapist.An earlier version of this paper was presented at the American Association for Marriage and Family Therapy, Dallas, Texas, October 29, 1982. Appreciation is expressed to Alice Lynn for her comments and suggestions on an earlier draft of this paper. The author has also benefitted from discussions with Douglas Sprenkle on paradigms and contexts.  相似文献   
958.
This investigation was designed to ascertain the effects of instructions, criterion setting, and the presence of tangible rewards on the self-reinforcement process. Fifty-two third- and fourth-grade subjects were assigned to one of four treatment groups: (a) stringent instructions/criterion setting/tangible reward, (b) stringent instructions/criterion setting/no tangible reward, (c) nonstringent instructions/criterion setting/tangible reward, and (d) nonstringent instructions/no tangible reward. In the stringent-instruction conditions, subjects received social reinforcement for selecting stringent performance criteria, whereas in the non-stringent-instruction conditions, social reinforcement was withheld. Subjects in the tangible-reward groups were allowed to select a prize following the successful completion of their self-selected work performance. Subjects in the no-tangible-reward groups received no prizes for their work. All subjects performed an arithmetic task in which the number of correct problems completed, number of problems attempted, and time at task served as dependent variables across five reinforcement and two extinction trials. The results suggest that the condition of stringent instructions, criterion setting, and tangible reward was more effective in producing behavior change than the other three conditions. Perceived task difficulty and previous achievement on arithmetic task performance were shown to affect criteria selected and mathematical performance. The results are discussed in light of the contributory role of instructions, criterion setting, and tangible rewards on the self-reinforcement procedure.This study is based on a doctoral dissertation submitted to the Faculty of Arts and Sciences at the University of Pittsburgh by Helen L. Evans. Dr. Russell T. Jones was the dissertation committee chairperson. It was partially funded by an American Psychological Association Minority Fellowship awarded to the first author. Special thanks are extended to the committee members, Drs. Lloyd Bond, Robert Glaser, Johnny Matson, and Samuel M. Turner, for their assistance. The authors would like to thank Thomas DeVoge, Paul Karoly, and Samuel M. Turner for reading and commenting on an early draft of this study. Portions of this paper were presented at the 1982 APA convention.  相似文献   
959.
Three experiments are described which elaborate some of the conditions under which rats will contact and manipulate a periodically presented retractable lever. Experiment 1 demonstrated that (i) initial manipulative oral and manual contact with the lever was facilitated if the rat had previous experience of food delivery in the experimental chamber; (ii) persistence in contacting the lever on successive presentations was a function of whether food continued to be presented in the experimental environment; and (iii) food satiation significantly reduced the tendency of the rat to contact the lever even though an expectancy of food had previously been established under conditions of food deprivation. Experiment 2 suggested that the tendency to approach and contact the lever was in part a function of the local moment-to-moment conditional probability of food delivery. Experiment 3 found that the probability of contacting the lever was higher during presentation of an auditory CS signaling a high rate of food delivery than during stimuli signaling no food at all. These results are interpreted as suggesting that the food-signaling aspects of an appetitive CS and that CS's ability to generate signal-directed behaviors are experimentall separable properties.  相似文献   
960.
Introduction     
J. N. Mohanty 《Man and World》1984,17(3-4):241-243
  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