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The experiment was designed to find the shape of food satiation curves of the pigeon as a function of hours of deprivation or percentage of free-feeding weight, and to study the fluctuation in free-feeding weight as a function of deprivation and satiation. At a systematically and progressively increased number of hours'' deprivation, eight birds were allowed to satiate on grain presented contingent upon the emission of a pecking response. In the second part of the experiment, in which two birds were used, a similar procedure was followed except that the independent variable was percentage of free-feeding weight. These were the conclusions.1. Approximately 64% of the satiation curves were classified as straight with an abrupt stop. The next highest percentage of curves was 18% for curves classified as straight with a curvilinear stop. No “classic” satiation curves, curvilinear with curvilinear stop, were found.2. The pigeons responded at fairly constant rate during the early part of each satiation session, or they did not respond at all. The critical weight, above which they did not respond, was 85% of free feeding.  相似文献   
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Two studies were conducted to explore the degree to which single- and multiple-risk profiles were evident in samples of African American early adolescents in low-income inner-city, rural, and suburban schools. Study 1 examined early adolescent risk status (i.e., single, multiple) in relation to later adjustment in a representative sample (70% European American, 30% African American). Youth who experienced a single risk in early adolescence had moderately increased levels of school dropout and criminal arrests, whereas youth with multiple risks (i.e., combination of 2 or more risks) had significantly increased levels of school dropout, criminal arrests, and teen parenthood. Study 2 examined the extent to which single- and multiple-risk profiles were evident in cross-sectional samples of African American youth from low-income inner-city and rural areas. About one fourth of both the inner-city and rural samples of African American youth were composed of youth in the single-risk category. A significantly greater proportion of boys in the inner-city sample (20%) than boys in the rural sample (13%) experienced multiple risks. Girls across the rural and inner-city samples did not differ in terms of risk. Overall, more than 60% of African American youth in these two low-income samples did not evidence risk for later adjustment problems. Implications for research and intervention are discussed.  相似文献   
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This summary review of work from one specialized laboratory provides background for the ensuing theoretical discussion concerning experimental neurosis in one inbred strain of purebred pointers. These animals respond selectively to negative reinforcements provided adventitiously in the laboratory environment. The inherited vulnerability of this neurotic strain is contrasted with the high “immunity” of a parallel line in the same laboratory environment.  相似文献   
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AIDS (Acquired Immune Deficiency Syndrome) education is the only effective method of reducing the transmission of HIV (human immunodeficiency virus) disease. The authors of this article compare the AIDS epidemic to past epidemics, including social and political responses. Populations at risk for HIV infection are identified, and the authors discuss current social and economic factors affecting AIDS education programs. Recommendations are made and resources are identified for starting a community-based AIDS education program.  相似文献   
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Young men and women today face considerable choices as they plan for family and work. We explore college students' educational preparations, as well as their attitudes, orientations, and expectations for work and family. Although we find some changes toward a more gender-equal society, we also find potential conflicts which these individuals will have to face as they attempt to combine work and family roles. Women and men are doing equally well in college, both men and women have equal commitments to work roles, and both value family. However, both men and women expect that women will play a more prominent role in the family and men a stronger role in the workplace. The orientation and plans of these college students do not anticipate symmetrical relationships in which both men and women share household and work responsibilities.We are grateful to Brenda K. Hawks, Sue Curry Jansen, and Judith Lasker for their careful readings of earlier drafts of this paper. Special thanks go to the students in SR377/477 for their major contribution in collecting the data which are analyzed herein.  相似文献   
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Talk about past events can be classified as either reminiscing (discussing shared experiences) or recounting (discussing unshared experiences). Reminiscing may have more of a social memory function whereas recounting may also be informational. This research focused on the form of mother–child reminiscing and recounting during the preschool years. Twenty 40‐month‐old and 20 58‐month‐old children reminisced and recounted past events with their mothers. Results showed that mothers who provided more memory information during reminiscing and requested more memory information during recounting had children who reported more unique information about the events. Regardless of maternal conversational style, however, children reported more unique memory information during recounting than reminiscing. We discuss these results in terms of the importance of both forms of remembering for autobiographical memory development. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
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Conducted a qualitative investigation to identify the perceptions of risk factors for violence in a sample of inner-city African American youth. Using ethnographic analyses, themes emerging from these data included concerns about the reciprocity between drugs and violence, familial quality of life issues, gender differences in the experience of violence and risk for violence, community safety concerns, and fears about managing peer relationships specific to violence. These data are interpreted relative to the risk factors the violence prevention literature has identified among youth residing in urban environments. Findings are discussed in terms of their potential contribution to generating hypotheses for the development of theory and effective violence prevention practice.  相似文献   
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