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   13479篇
  免费   425篇
  国内免费   8篇
  2019年   145篇
  2018年   245篇
  2017年   223篇
  2016年   243篇
  2015年   190篇
  2014年   196篇
  2013年   1211篇
  2012年   434篇
  2011年   428篇
  2010年   260篇
  2009年   311篇
  2008年   412篇
  2007年   452篇
  2006年   395篇
  2005年   373篇
  2004年   362篇
  2003年   394篇
  2002年   380篇
  2001年   322篇
  2000年   310篇
  1999年   271篇
  1998年   154篇
  1997年   166篇
  1996年   168篇
  1995年   170篇
  1994年   141篇
  1993年   169篇
  1992年   219篇
  1991年   209篇
  1990年   191篇
  1989年   177篇
  1988年   171篇
  1987年   192篇
  1986年   188篇
  1985年   194篇
  1984年   208篇
  1983年   200篇
  1982年   150篇
  1981年   154篇
  1980年   159篇
  1979年   201篇
  1978年   182篇
  1977年   169篇
  1976年   168篇
  1975年   157篇
  1974年   185篇
  1973年   188篇
  1972年   129篇
  1970年   118篇
  1968年   149篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
171.
The experiments examined the contributions of forebrain noradrenaline and environmental enrichment to recovery of place navigation ability in rats after hemidecortication in infancy or adulthood. Noradrenaline depletion did not affect recovery from neonatal hemidecortication, although the early hemidecortications did allow sparing of function relative to adult operates. Noradrenaline depletion also failed to attenuate the positive effects of enriched housing on otherwise normal rats. Noradrenaline depletion did retard recovery of adult hemidecorticate rats housed in standard laboratory cages, but it did not retard recovery of adult hemidecorticate rats housed in enriched environments. The results suggest that noradrenaline is importantly involved in enhancing recovery from brain damage when other sources of compensation (e.g., neonatal injury, enriched environment) are absent.  相似文献   
172.
Attitudes toward posthumous organ donation and commitment to donate   总被引:4,自引:0,他引:4  
The medical need for human organs suitable for use as transplants far exceed the supply, and is growing. More favorable attitudes about organ donation would increase people's willingness to sign posthumous donation pledges. But effective educational programs require information about the public's present views. Verbal attitude scales were constructed and administered to 110 adults, resulting in reliable measurement of two independent dimensions, prodonation and antidonation (r = .003). Cluster analysis of the instrument revealed that the positive dimension involves belief in the humanitarian benefits of organ donation and feelings of pride experienced by the donor. The negative dimension reflects fears of body mutilation and of receiving inadequate medical treatment when one's life is at risk. Pro and anti scores in combination predicted willingness to sign a donor card. A 2 X 2 analysis of variance (High-Low Positive X High-Low Negative) revealed significant main effects for both positive and negative attitude. Also, a significant interaction effect was obtained. Those subjects who had both strong positive attitudes and weak negative attitudes were especially willing to sign donor cards. Suggestions for designing educational campaigns to promote organ donation are offered.  相似文献   
173.
174.
This study tested the applicability of a cognitive-motivational model of health behavior to children's food choices. A sample of 107 elementary schoolchildren provided ratings of 15 foods in terms of possible choice criteria (e.g., how tasty or healthful specific foods were) and social or environmental influences (e.g., whether foods were eaten by friends or were easy to get). Several measures of food consumption were taken, and cognitive-developmental level was assessed. Within-person correlations were calculated between food choices and each choice criterion and social/environmental factor. These "correlational indices" of influences on food choice subsequently were used to identify five distinct subgroups in the sample. Children at the operational level of cognitive development tended to be in one of three groups characterized by health orientation in food choice, taste orientation, or multiple-motive orientation. Dietary quality was poorest in the taste-oriented group. Children at the preoperational level tended to have one of two undifferentiated patterns of values across the correlational indices. Results provide evidence of: the viability of cognitive-motivational models to explain children's food choices, the promise of within-person research methodology, and the potential for enhanced health behavior-change programs by use of population segmentation and tailored interventions.  相似文献   
175.
176.
177.
The social adjustment of the adolescent offspring of parents with bipolar affective disorder (n=41) was compared to that of the offspring of parents with nonaffective psychiatric disorders (n=22) and the offspring of normal controls (n=26). In addition, the relationship between social adjustment and cyclothymia in offspring was determined. Social adjustment was assessed using the Life Activities Inventory, a new measure developed to assess social functioning in adolescents and young adults. Cyclothymia was assessed with the General Behavior Inventory. As a group, the offspring of bipolar parents did not differ significantly from either control group on social adjustment. However, the cyclothymic offspring of bipolar parents exhibited significantly poorer social adjustment than the noncyclothymic offspring of bipolars and the offspring of psychiatric and normal controls. These findings suggest that poor social functioning in the adolescent offspring of parents with bipolar illness may be associated with the early manifestations of affective disorder. In addition, these data indicate that despite its subsyndromal intensity, cyclothymia can result in significant social impairment.This study was supported in part by National Institute of Mental Health (NIMH) Research Grant MH-39782 to Daniel N. Klein and NIMH Grants MH-33083 and MH-37195 to Richard A. Depue.  相似文献   
178.
This study examined the implications for social comparison theory of the proposition that women have lower self-confidence than men when there is a socially defined standard of performance. To this end, it was hypothesized that women would judge themselves to be similar to a lower ranked person, whereas men would judge themselves to be similar to a higher ranked person. Furthermore, it was hypothesized that women would choose to see a score lower than their own, whereas men would choose to see a score higher than their own. The results on the measure of similarity indicated that men did judge themselves to be similar to a higher ranked person, whereas women showed no consistent preferences in their judgments of similarity. The results on the choice of a comparison other were not as clear-cut.  相似文献   
179.
180.
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