全文获取类型
收费全文 | 4911篇 |
免费 | 538篇 |
国内免费 | 364篇 |
出版年
2024年 | 18篇 |
2023年 | 159篇 |
2022年 | 84篇 |
2021年 | 125篇 |
2020年 | 257篇 |
2019年 | 284篇 |
2018年 | 321篇 |
2017年 | 295篇 |
2016年 | 292篇 |
2015年 | 175篇 |
2014年 | 196篇 |
2013年 | 962篇 |
2012年 | 120篇 |
2011年 | 124篇 |
2010年 | 115篇 |
2009年 | 178篇 |
2008年 | 210篇 |
2007年 | 251篇 |
2006年 | 276篇 |
2005年 | 228篇 |
2004年 | 178篇 |
2003年 | 149篇 |
2002年 | 131篇 |
2001年 | 127篇 |
2000年 | 89篇 |
1999年 | 81篇 |
1998年 | 46篇 |
1997年 | 68篇 |
1996年 | 57篇 |
1995年 | 46篇 |
1994年 | 46篇 |
1993年 | 23篇 |
1992年 | 25篇 |
1991年 | 13篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 7篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 1篇 |
排序方式: 共有5813条查询结果,搜索用时 15 毫秒
41.
Shayna Skakoon-Sparling Paolo A. Palma Adhm Zahran Trevor A. Hart David M. Moore Joseph Cox Nathan J. Lachowsky Milada Dvorakova Emerich Daroya Daniel Grace 《Social and Personality Psychology Compass》2023,17(9):e12814
In March 2020, in response to the COVID-19 pandemic, Canadian provincial governments instituted a variety of public health measures that included social distancing and isolation, which may have had unintended consequeses. According to the Loneliness and Sexual Risk Model, gay, bisexual, and other men who have sex with men (GBM) often cope with loneliness through risky sexual behaviors. Previous studies have demonstrated that COVID-19 measures such as social distancing and isolation led to increases in loneliness; thus, these measures may also have led to elevated sexual risk-taking among some GBM. Participants were recruited from an ongoing cohort study on GBM health and well-being, and were included in the current analysis if they had completed relevant study questions (n = 1134). GBM who reported lower levels of social support pre-COVID-19, were younger, and lived alone each reported greater loneliness during the first year of COVID-19. Although feelings of loneliness did not predict sexual risk-taking within the first year of COVID-19, loneliness did predict greater sexual risk-taking 6 months later. Additionally, younger GBM and those living alone were more likely to engage in sexual risk-taking at both COVID-19 data collection points. These findings offer some support of the Loneliness and Sexual Risk Model; however, it is possible that the unique circumstances of the COVID-19 pandemic resulted in a temporary suspension of this association, as many GBM took steps to protect themselves and partners in the context of COVID-19. 相似文献
42.
Peter D. Mott 《Theoretical medicine and bioethics》1990,11(2):95-102
The issues involved in decision making about the aggressiveness of future medical care for older persons are explored. They are related to population trends, the heterogeneity of older persons and a variety of factors involved in individual preferences. Case studies are presented to illustrate these points, as well as a review of pertinent literature. The argument is offered that, considering these many factors, a system of flexible, individualized care by informed patient preference, is more rational than the rationing of technological services by age. 相似文献
43.
Carol Taylor 《Theoretical medicine and bioethics》1990,11(2):111-124
In this paper a case is used to demonstrate how ethical analysis enables health care professionals, patients and family members to make treatment decisions which ensure that medical technologies are used in the overall best interests of the patient. The claim is made and defended that ethical analysis can secure four beneficial outcomes when medical technologies are employed: (1) not allowing any medical technologies to be employed until the appropriate decision makers are identified and consulted; (2) insisting that medical technologies be employed not merely to promote the medical interests of the patient but rather on the basis of their ability to contribute to the overall well-being of the patient; (3) challenging caregivers to reflect on the dynamic interplay between their conscious and unconscious values and consequent determinations of what is in the patient's best interests; and (4) providing a justification for selected interventions which makes possible rational dialogue between caregivers espousing different viewpoints about treatment options. 相似文献
44.
Lindsay St. Claire 《Journal of community & applied social psychology》1993,3(3):183-195
Briefs about mentally retarded people are more negative than briefs about other social categories; professionals, such as medical doctors evaluate them most negatively of all. It was hypothesized (a) that medics' beliefs about mentally retarded people are mediated by psychological salience of their clinical social identification, rather than by personal characteristics that medics happen to share and (b) that such beliefs will bias decisions, rather than enhance accuracy. Forty-five doctors and medical students were randomly assigned to conditions designed to enhance salience of their shared clinical social identification or individual self-perceptions. Subjects completed semantic differentials about mentally retarded people and distinguished between slides of ‘mentally retarded’ and ‘normal’ children. Beliefs of subjects in the medical condition were significantly more negative than those in the personal condition. A signal detection analysis revealed no difference between conditions in subjects' ability to distinguish between children but showed that subjects in the medical condition were significantly more likely to judge a child ‘mentally retarded’ when in doubt. Results were discussed within an information processing framework and supported the idea that a salient clinical social identity can mediate beliefs that are likely to handicap patients. 相似文献
45.
Ronald C. Martella Ph.D. Ian J. Leonard B.S. Nancy E. Marchand-Martella Ph.D. Martin Agran Ph.D. 《Journal of Behavioral Education》1993,3(1):77-86
We examined the effects of a self-monitoring program on reducing the frequency of negative statements of a student with mild mental retardation who was enrolled in a self-contained classroom at a middle school. A changing criterion design was used within a multiple baseline design across two classroom periods. Additionally, the frequency of positive statements was reported. The results showed a decrease in the number of negative statements, and an increase in the number of positive statements. Maintenance data collected up to 8 weeks after the program ended indicated that the student continued to emit positive rather than negative statements. The use of this procedure to decelerate undesirable behavior is discussed. 相似文献
46.
Kimberly Hoagwood Ph.D. Ann A. Hohmann Ph.D. M.S.P.H. 《Journal of child and family studies》1993,2(3):259-268
This article describes an important new area of research on services for children and adolescents with mental disorders at the National Institute of Mental Health, the parameters of mental health services research for youth, and the opportunities that are available for grant-funded investigations in this area. 相似文献
47.
K. W. M. Fulford 《Theoretical medicine and bioethics》1993,14(4):305-320
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
48.
Jack W. Finney Kathryn M. Miller Stuart P. Adler 《Journal of applied behavior analysis》1993,26(4):471-472
Child-to-parent transmission of cytomegalovirus may be reduced by increasing protective behaviors (handwashing and glove use) and decreasing risky behaviors (intimate contact between child and parent). This study showed that an educational intervention resulted in increases in reported and objective measures of protective behaviors and decreases in reported risky behaviors. Further study must determine if changes in protective and risky behavior are maintained and prevent cytomegalovirus transmission. 相似文献
49.
Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond the effect exerted by frequency of primary reinforcement. 相似文献
50.
A range of health behaviors was related to beliefs concerning health practices and health knowledge. A questionnaire dealing with health-related practices, health beliefs and knowledge of health risk factors was answered by 166 male and 179 female students aged 18–30 years at Stockholm University. Female students reported engaging in better health behavior than males. Beliefs about the importance of health behaviors were closely related to their frequency of occurrence. There was only a weak relationship between health behaviors and knowledge of specific health matters. It is concluded that health attitudes rather than health knowledge determine health behavior. 相似文献