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   52497篇
  免费   2106篇
  国内免费   32篇
  2020年   594篇
  2019年   745篇
  2018年   1067篇
  2017年   1077篇
  2016年   1119篇
  2015年   745篇
  2014年   927篇
  2013年   4576篇
  2012年   1670篇
  2011年   1825篇
  2010年   1058篇
  2009年   1079篇
  2008年   1654篇
  2007年   1625篇
  2006年   1431篇
  2005年   1299篇
  2004年   1280篇
  2003年   1157篇
  2002年   1200篇
  2001年   1764篇
  2000年   1662篇
  1999年   1270篇
  1998年   668篇
  1997年   576篇
  1996年   521篇
  1995年   528篇
  1994年   500篇
  1993年   517篇
  1992年   1010篇
  1991年   959篇
  1990年   945篇
  1989年   850篇
  1988年   820篇
  1987年   804篇
  1986年   806篇
  1985年   857篇
  1984年   671篇
  1983年   576篇
  1982年   472篇
  1979年   656篇
  1978年   487篇
  1976年   447篇
  1975年   589篇
  1974年   620篇
  1973年   594篇
  1972年   539篇
  1971年   474篇
  1968年   539篇
  1967年   540篇
  1966年   475篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
811.
812.
Effects of smoking on spontaneous bilateral skin conductance were studied as a consequence of interactions with set and setting. Bilateral skin conductance was recorded in six men and six women who smoked and an equal number of nonsmokers on two different days. On the first day, spontaneous electrodermal activity was recorded before and after a 10-minute rest period during which half the smokers smoked a cigarette. On the second day, one week later, spontaneous activity was again recorded before and after a 10-minute rest period during which the remaining smokers smoked a cigarette. Nonsmokers did not smoke at any time. Following smoking there was a significant negative correlation between a preference for visual over nonvisual imagery and spontaneous skin conductance responsivity in the left as compared to the right hand. Correlations were significantly different in smokers and nonsmokers. Smokers showed significantly greater preferences for either visual or nonvisual imagery than nonsmokers. Nonresponding nonsmokers were higher on the psychoticism (P) scale of the Eysenck Personality Questionnaire (EPQ) than responding nonsmokers. Smokers scored higher on P than nonsmokers. Interactions between personality, cognitive style, and the experimental situation, set, and setting were discussed in relation to the arousing effects of nicotine.  相似文献   
813.
814.
Among a sample of American college students, body image and the degree of desired weight change were associated with academic self-rankings, with social and psychological well-being, and with the development of eating difficulties. The effects of body image and desired weight change on eating disorders were generally found to be greater for women than for men, and their effects on student self-rankings of academic ability, social, and psychological traits were more pervasive for women than for men. The less attractive a woman perceived herself to be and the more weight she wanted to lose, the greater was her overall sense of academic, social, and psychological impairment. Women who had poor body images and who desired to lose weight were more likely to report eating difficulties.  相似文献   
815.
A questionnaire monitoring occupational aspiration, ethnic identification, adolescent experience, and self-esteem was administered to a large sample of Indian and Anglo-Saxon British male and female adolescents attending school in the West Midlands. The relationship between these variables and differences between the four groups were consistent with predictions derived from the social identity approach to intergroup relations and group behaviour (Tajfel & Turner, 1979). Indian males were found to possess a social mobility belief structure that mediates high occupational aspirations and keeness to marry out of their ethnic group. In contrast, Indian females were found to possess a social change belief structure associated with acceptance of the status quo and lower aspirations. Males and Anglo-Saxons reported higher self-esteem than females or Indians. The adolescent experience findings were less clear, but were consistent with the general interpretation of the data that the differences in intersex relations and gender-related experiences are contingent on ethnicity.  相似文献   
816.
In this paper, we present a BASIC program for Apple II series computers that allows the user to obtain perspective drawings of two-dimensional functions of known analytical expression. Also, we outline a procedure for obtaining perspective representations of two-dimensional arrays of data using the same program. The program should run on any computer with graphics mode with only slight modifications in the graphics commands.  相似文献   
817.
A suite of programs is described for simulating the Rescorla-Wagner (1972) model of associative learning, the Solomon and Corbit (1974) opponent-process theory, and Schull’s (1979) extension of the latter. The programs are written for the Commodore 64 computer.  相似文献   
818.
The objective of this study was to determine what amount of change in heart electrophysiology is necessary to yield a significant difference between a baseline condition and an experimental treatment condition. In a single-subject longitudinal design, a modification of at test was applied to baseline data, and the performance levels for both .05 and .01 probability levels were obtained. It was concluded that it is both ethically sound and physiologically safe to permit a subject in this type of experiment to physiologically respond at levels that would reach both the .05 and the .01 levels of significance.  相似文献   
819.
W E Thompson  R A Dodder 《Adolescence》1986,21(82):365-376
All seven variables of containment theory were operationalized for questionnaires. Data were collected from 677 adolescents in a variety of high schools and correctional institutions, and divided into categories by race and sex. Factor analysis indicated that the structure of the relationships among the seven containment variables and delinquency was substantially different among black females.  相似文献   
820.
This study measured students' attitudes toward a university's student health services (SHS) and identified factors that were related to their attitudes. A questionnaire surveying students' attitudes was administered to a sample of 150 students at the Oxford Campus of the University of Mississippi. Analysis of the data revealed that students' attitudes had a statistically significant correlation with the following variables: perceived medical care cost, amount of health information/education received during medical encounters, time spent in the waiting room of the SHS, sex of the student, and income of the student. There was no significant relationship between attitude and age.  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