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   32992篇
  免费   620篇
  国内免费   2篇
  33614篇
  2019年   365篇
  2018年   476篇
  2017年   519篇
  2016年   555篇
  2015年   409篇
  2014年   525篇
  2013年   2577篇
  2012年   872篇
  2011年   916篇
  2010年   645篇
  2009年   591篇
  2008年   888篇
  2007年   820篇
  2006年   789篇
  2005年   686篇
  2004年   697篇
  2003年   680篇
  2002年   737篇
  2001年   737篇
  2000年   740篇
  1999年   621篇
  1998年   389篇
  1997年   388篇
  1996年   380篇
  1995年   373篇
  1992年   578篇
  1991年   535篇
  1990年   525篇
  1989年   493篇
  1988年   495篇
  1987年   460篇
  1986年   507篇
  1985年   500篇
  1984年   472篇
  1983年   449篇
  1981年   398篇
  1979年   513篇
  1978年   437篇
  1977年   383篇
  1976年   382篇
  1975年   441篇
  1974年   531篇
  1973年   522篇
  1972年   399篇
  1971年   408篇
  1970年   372篇
  1969年   415篇
  1968年   476篇
  1967年   433篇
  1966年   449篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
981.
982.
983.
984.
In this paper, we applied the behavioral-economic concept of unit price to the study of reinforcer magnitude in an attempt to provide a consistent account of the effects of reinforcer magnitude on behavior. Recent research in the experimental analysis of behavior and in behavioral pharmacology suggests that reinforcer magnitude interacts with the schedule of reinforcement to determine response rate and total consumption. The utility of the unit-price concept thus stems from its ability to quantify this interaction as a cost-benefit ratio (i.e., unit price = characteristics of the schedule of reinforcement divided by magnitude of reinforcement). Research employing the unit-price concept has shown that as unit price increases, a positively decelerating function exists for consumption (i.e., a function with an increasingly negative slope, when plotted on log coordinates) and a bitonic function exists for response rate. Based on these findings, the present analysis applied the unit-price concept to those studies of reinforcer magnitude and drug self-administration that examined the effects of reinforcer magnitude on response rate using simple schedules of reinforcement (e.g., fixed-ratio schedule). This resulted in three findings: (a) Reinforcer-magnitude manipulations and schedule manipulations interact in a manner that can be quantified in terms of unit price as benefit and cost factors, respectively; (b) different reinforcer-magnitude manipulations are functionally interchangeable as benefit factors in the unit-price ratio; and (c) these conclusions appear warranted despite the differences in reinforcers (food or drug), species (dogs, monkeys, or rats), and schedules (interval or ratio), and despite the fact that these studies were not designed for a unit-price analysis. In methodological terms, these results provide further evidence that employing the unit-price concept is a parsimonious method for examining the effects of reinforcer magnitude. In theoretical terms, these results suggest that a single process may underlie the effect of combined reinforcer-magnitude and schedule manipulations.  相似文献   
985.
Analyses of biological concepts of disease and social conceptions of health indicate that they are structurally interdependent. This in turn suggests the need for a bridge theory of illness. The main features of such a theory are an emphasis on the logical properties of value terms, close attention to the features of the experience of illness, and an analysis of this experience as action failure, drawing directly on the internal structure of action. The practical applications of this theory are outlined for a number of problems in each of the three main practical areas, clinical work, teaching and research. In each case the resources of the theory suggest new models and generate new results. The full practical significance of the theory, however, is shown to consist in the way in which it ties together biological and social theories into an integrated picture of the conceptual structure of medicine as a whole. It is argued, finally, that practical efficiency of this kind is a test of theory not only in the philosophy of medicine but also in general philosophy.  相似文献   
986.
987.
Wide-area computer networks provide a wealth of information services that have the potential to alter the approach toward scholarship taken by both students and researchers. Although it can be argued that the translation of information from hard copy to a publicly accessible electronic form has developed slowly, the total volume of text-based information that has been digitized is already staggering. Two major challenges facing psychologists wishing to develop their skills in network use are to identify and locate pertinent information that is accessible, and to find an easy way to retrieve it. This paper is an attempt to provide an overview of network resources and services that may be of particular interest to psychologists and psychology students. Its focus is on how to learn more about the available information services, as well as how to make access as user friendly as possible.  相似文献   
988.
In this study the authors investigated the relationship between the Male Role Norm Scales (MRNS; Thompson & Pleck, 1987) and gender-related attitudes and behaviors in a sample of 367 male counselors drawn from American Counseling Association (ACA), formerly the American Association for Counseling and Development (AACD), members. Results indicated that this group of men did not, in general, endorse traditional male roles as measured by the MRNS. When a degree of affiliation with these roles was found, however, it was predictive of violence proneness, intimacy style, and degree of perceived similarity to father. Implications for training and counseling are discussed.  相似文献   
989.
This is a critical analysis of how cultivation has been conceptualized in theory and research. Cultivation indicators are examined for their meaning in texts, the meaning received by viewers, and the distinction between estimations and beliefs. The construct of television exposure is analyzed in terms of the assumptions of uniform messages and nonselective viewing, as well as the conception of time and dominance. The nature of relationship is illuminated through the assumptions of linearity, asymmetry, control variables, causation, level of generality, mainstreaming, and resonance. Recommendations are provided to suggest revisions for conceptualizing the existing theory and extending it. Suggestions for extension include reconceptualizing the effect and the relationship, developing a typology of effects, considering the context of other simultaneous influences, providing analysis over time, and examining the process of influence on individuals and on the messages.  相似文献   
990.
Adolescents tend to categorize themselves and their peers into discrete ingroups and outgroups. A comparison of ingroup versus outgroup perceptions of the characteristics of high-risk youth was investigated. Based on current stereotype research, we examined the perspective that outgroup members would hold a more extreme stereotype of high-risk youth compared to the perceptions of ingroup members. A total of 955 7th- and 10th-grade southern California adolescents completed a questionnaire regarding the characteristics of their own peer group and a high-risk group. Support was obtained for an extremity of judgement effect. Outgroup youth perceived that their high-risk peers engaged in fewer school and nonschool low-risk activities, more high-risk activities, and greater drug use than did ingroup members. Outgroup members also held perceptions of high-risk youth as less likely to hold a white-collar job than did the ingroup members. The perceptions that adolescents have of these groups may play major roles in their own social behavior. The implications of these results for future tobacco use prevention programs are considered.  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