全文获取类型
收费全文 | 55817篇 |
免费 | 2334篇 |
国内免费 | 21篇 |
专业分类
58172篇 |
出版年
2020年 | 678篇 |
2019年 | 791篇 |
2018年 | 1132篇 |
2017年 | 1142篇 |
2016年 | 1195篇 |
2015年 | 855篇 |
2014年 | 1035篇 |
2013年 | 4832篇 |
2012年 | 1930篇 |
2011年 | 1930篇 |
2010年 | 1154篇 |
2009年 | 1182篇 |
2008年 | 1668篇 |
2007年 | 1629篇 |
2006年 | 1493篇 |
2005年 | 1236篇 |
2004年 | 1280篇 |
2003年 | 1227篇 |
2002年 | 1165篇 |
2001年 | 1922篇 |
2000年 | 1797篇 |
1999年 | 1342篇 |
1998年 | 617篇 |
1997年 | 530篇 |
1996年 | 610篇 |
1995年 | 549篇 |
1994年 | 543篇 |
1993年 | 526篇 |
1992年 | 1106篇 |
1991年 | 1017篇 |
1990年 | 997篇 |
1989年 | 957篇 |
1988年 | 934篇 |
1987年 | 865篇 |
1986年 | 858篇 |
1985年 | 905篇 |
1984年 | 729篇 |
1983年 | 627篇 |
1979年 | 758篇 |
1978年 | 562篇 |
1975年 | 602篇 |
1974年 | 681篇 |
1973年 | 701篇 |
1972年 | 604篇 |
1971年 | 561篇 |
1970年 | 483篇 |
1969年 | 478篇 |
1968年 | 609篇 |
1967年 | 530篇 |
1966年 | 506篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
132.
Through school-sponsored health fairs, 398 adolescents (153 males and 245 females) between the ages of 14 and 18 completed a questionnaire on their compliance with six of the U.S. Dietary Guidelines. Results indicated that adolescents report highest compliance on "eat a variety of foods" and "eat foods with adequate starch and fiber." Conversely, they indicated low compliance on "reduce sugar intake" and "reduce fat, saturated fat and cholesterol intake." Sex differences were noted on two dietary guidelines. Females reported lower compliance with respect to "maintain desirable body weight." Males, on the other hand, reported lower compliance than females on "reduce salt intake." Given the fact that the dietary guidelines of "reduce fat, saturated fat and cholesterol," "maintain desirable body weight," and "reduce salt intake" are all aimed at reducing cardiovascular risk, the low compliance reported by adolescents may have long-range health implications. 相似文献
133.
General self-esteem of adolescents from ethnic minorities in The Netherlands and the reflected appraisal process 总被引:1,自引:0,他引:1
M Verkuyten 《Adolescence》1988,23(92):863-871
This article examines the question of how the lack of differences in general self-esteem between adolescents of ethnic minorities and Dutch adolescents can be explained. Attention is focused on the reflected appraisal process. It was found that for adolescents of ethnic minorities there is a significant relationship between general self-esteem and the perceived evaluation of family members, and no such relationship with nonfamily members. For the Dutch adolescents the findings are the opposite, which may explain why adolescents of ethnic minorities in general do not have lower general self-esteem, despite low status, prejudice, and discrimination. 相似文献
134.
135.
136.
137.
138.
Perlin E 《Journal of religion and health》1988,27(4):279-284
The care of the patient with cancer requires the development not only of a medical plan, but an ethical plan as well. This plan should integrate the physician's and the patient's perceptions of medical and ethical propriety. Jewish biomedical ethical principles are based on the teaching of the Old Testament and its various interpretations. In this paper, I discuss how these principles can be used to help guide the physician caring for the patient with cancer. Other ethical systems could be applied in a similar fashion. 相似文献
139.
Jacqueline M. Golding Patricia Gongla Arlene Brownell 《American journal of community psychology》1988,16(1):39-51
Survey respondents may inaccurately report mental health service utilization for motivational and cognitive reasons. There is little evidence on accuracy of self-reports of mental health service use, and this evidence suggests that respondents tend to underreport inpatient utilization. This study addressed the question of self-report accuracy by comparing survey data from a large probability sample to data from computerized records of publicly funded mental health services. Few inaccuracies in self-reporting were detected. However, despite the use of data bases that were unusually appropriate for verifying self-reports, several problems limited the feasibility of validation. Suggestions are offered for increasing the feasibility of validation in future studies. 相似文献
140.
Processing resources and age differences in working memory 总被引:1,自引:0,他引:1
This study investigated the performance of young and old subjects on a modified version of the working memory task developed by Baddeley and Hitch (1974). Subjects were required to verify a set of sentences of varying complexity while they repeated aloud zero, two, or four words. The older subjects took longer to verify the sentences, especially when the sentences were grammatically complex, but the effect of concurrent memory load on verification latency was the same in both groups. These results cast doubt on the notion that there is an age-related decline in one general pool of processing resources. They also suggest that older people have greater difficulty with the active processing aspects, rather than with the passive holding aspects, of working memory tasks. 相似文献