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   1701篇
  免费   64篇
  国内免费   1篇
  2019年   22篇
  2018年   39篇
  2017年   28篇
  2016年   57篇
  2015年   22篇
  2014年   30篇
  2013年   124篇
  2012年   48篇
  2011年   65篇
  2010年   37篇
  2009年   37篇
  2008年   53篇
  2007年   47篇
  2006年   52篇
  2005年   43篇
  2004年   59篇
  2003年   47篇
  2002年   53篇
  2001年   49篇
  2000年   41篇
  1999年   36篇
  1998年   23篇
  1997年   20篇
  1995年   17篇
  1994年   23篇
  1993年   23篇
  1992年   26篇
  1991年   28篇
  1990年   27篇
  1989年   19篇
  1988年   18篇
  1987年   22篇
  1986年   24篇
  1985年   28篇
  1984年   21篇
  1983年   19篇
  1982年   23篇
  1981年   20篇
  1980年   15篇
  1979年   31篇
  1978年   18篇
  1977年   19篇
  1975年   22篇
  1974年   28篇
  1973年   28篇
  1972年   25篇
  1971年   25篇
  1969年   19篇
  1968年   18篇
  1967年   17篇
排序方式: 共有1766条查询结果,搜索用时 31 毫秒
51.
Biotechnological advance is speeding the development of drugs. The approval processes for new drugs will inevitably involve a regulatory agency in making political-economic and scientific choices. Interests of specific patients and the public in general are to be considered, and enormous stakes are involved for companies concerned. A medical regulatory authority must be at once insulated from and responsive to many different mixes of singular and general interests and pressures. Access to new drugs can be spurred by the press of patient advocacy groups, but if there are well organized groups to monitor the testing and approval process for such as AIDS or cancer drugs there is often no similar group to represent patient needs. If there is no organized patient advocacy group, compassionate responsibility by a medical regulatory authority is indeed called for. Delay in the approval of new drugs for fighting severe blood infections raises the question of how to insure the compassionate responsibility of a regulatory authority.  相似文献   
52.
In this paper, it is proposed that a) psychosocial medicine is best taught in a setting that provides technical and emotional support, while seizing for teaching only those moments when the learner is most receptive; and b) that the setting should avoid the development of a separate psychosocial skills curriculum, but should take the student where he or she is and integrate the psychosocial skills into his or her everyday biomedical practice. The paper gives specific case examples in which family based psychosocial issues were preeminent in the clinical problem-solving medical residents faced.  相似文献   
53.
Ten subjects served as their own controls in two conditions of continuous, centrifugally produced hypergravity (+2 Gz) and a 1-G control condition. Before and after exposure, open-loop measures were obtained of (1) motor control, (2) visual localization, and (3) hand-eye coordination. During exposure in the visual feedback/hypergravity condition, subjects received terminal visual error-corrective feedback from their target pointing, and in the no-visual feedback/hypergravity condition they pointed open loop. As expected, the motor control measures for both experimental conditions revealed very short lived underreaching (the muscle-loading effect) at the outset of hypergravity and an equally transient negative aftereffect on returning to 1 G. The substantial (approximately 17°) initial elevator illusion experienced in both hypergravity conditions declined over the course of the exposure period, whether or not visual feedback was provided. This effect was tentatively attributed to habituation of the otoliths. Visual feedback produced a smaller additional decrement and a postexposure negative aftereffect, possible evidence for visual recalibration. Surprisingly, the target-pointing error made during hypergravity in the no-visual-feedback condition was substantially less than that predicted by subjects’ elevator illusion. This finding calls into question the neural outflow model as a complete explanation of this illusion.  相似文献   
54.
Considerable scientific evidence demonstrates the reduction in risk for neural tube defects (NTDs) associated with maternal preconceptional folic acid supplementation. The National Society of Genetic Counselors (NSGC) endorses the U.S. Public Health Service recommendations for folic acid supplementation at the 0.4 mg level for women in the general population and at the 4.0 mg level for women at high or increased risk for NTD pregnancies for at least 4 weeks prior to active pursuit of conception. We encourage targeted educational efforts and surveillance to assess results of this dietary supplementation. The NSGC further urges the Food and Drug Administration to fortify staple foodstuffs with folic acid for a population-based approach to minimize the number of NTD births.  相似文献   
55.
The current investigation examined the degree to which judges' ratings of skill, anxiety, and attractiveness are influenced by the responsivity of the confederate. High-, medium-, and low-skilled subject-pool groupings, as well as self-referred clinical groups, were exposed to either a moderately or a minimally responsive confederate. Results indicated that subjects were rated as more skillful when interacting with a moderately responsive confederate than when interacting with a minimally responsive confederate. Further, there was a groups × condition interaction for anxiety ratings such that both the high- and the medium-skilled groups appeared more anxious under the minimal condition, whereas the low-skilled and self-referred groups did not. Self-referred subjects received significantly lower attractiveness ratings than did the high- or medium-skilled groups. Implications of these results and future directions for research are discussed.This research is based on a M.S. thesis carried out by the first author under direction of the second author.  相似文献   
56.
Prominence of the brain's right-hemisphere information processing and intensity of dream experience are two theoretically related constructs that have been proposed as important psychological aspects of REM sleep. Either view is consistent with the prediction that the effect of REM deprivation will depend in part on the nature of cognitive activity that is initiated at the onset of each REM period and that "substitutes" for the interrupted REM process. In the present study, the effect of REM deprivation was more striking for female subjects given a digits task than for female subjects given a fantasy-reporting task during awakening used to induce REM deprivation for the first 6 hours of the night. High neuroticism appeared to exaggerate the effect. No corresponding pattern was observed for the male subjects. These preliminary finding may be exaggerated by cognitive activity that is functionally incongruent with those processes. The results also raise interesting questions about individual differences.  相似文献   
57.
58.
This article takes a sociological approach to a problem that has usually been considered as a psychological phenomenon. It addresses the problem of male—female interactions in work situations utilizing the organizational concepts of division of labor and legitimacy. Traditional explanations evoking sex-role socialization are reviewed and rejected for purposes of experimentation and intervention. An alternative argument, focusing on the structural arrangements of organizational settings, is presented as an explanation for behavioral effects previously attributed to inherent sex differences. The results of a pilot study are briefly described, and directions for further experimentation and possible intervention strategies are suggested.The bibliographic search and initial conceptualization of this research was supported by a grant from the Ford Foundation under the auspices of the Center for Research on Women at Stanford University. We are grateful to Miriam Rosen for much of the bibliographic work. The pilot study was supported in part by funds from the Guggenheim Foundation and by a grant from the Spencer Foundation. We also wish to thank Richard Torres and Christie Timberlake for their invaluable assistance on this project.  相似文献   
59.
Most psychological tests and inventories, particularly in personality and attitude measurement, contain common items, that is, various subscales of the test or inventory may share one or more items in common. Surprisingly, the role of common items in such a fundamental personality test attribute as reliability is not known. The present report specifically considered common-item contributions to test internal consistency reliability using extant data from the California Psychological Inventory. No negative contribution of item overlap was found. To the contrary, it was concluded that the use of common items is an economical technique for increasing the total number of items in the scales, thus increasing scale internal reliabilities without increasing the overall number of items in the inventory.  相似文献   
60.
This research examined the effects of a self-instruction intervention on the relationship between cognitive level and conceptual tempo. Preoperational and concrete operational children received the Matching Familiar Figures Test prior to and after serving in either a no training control group, a content only control group, or a self-instruction group. Children in the content only control group received the same set of self-guiding strategy statements as those in the self-instruction group but without overt rehearsal of the statements. Cognitive level and conceptual tempo were strongly related; preoperational children tended to be classified as impulsive, concrete operational chidlren, as reflective. Although cognitive level predicted overall performance, with concrete operational children being more successful and more reflective than preoperational children, the influence of training was similar for both groups. On posttest, children in the self-instruction groups made more correct responses and were more reflective than children in the other two training groups.  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