全文获取类型
收费全文 | 14030篇 |
免费 | 166篇 |
国内免费 | 7篇 |
专业分类
教育 | 10231篇 |
科学研究 | 1216篇 |
各国文化 | 80篇 |
体育 | 1123篇 |
综合类 | 7篇 |
文化理论 | 90篇 |
信息传播 | 1456篇 |
出版年
2021年 | 103篇 |
2020年 | 154篇 |
2019年 | 257篇 |
2018年 | 353篇 |
2017年 | 364篇 |
2016年 | 332篇 |
2015年 | 205篇 |
2014年 | 280篇 |
2013年 | 2587篇 |
2012年 | 303篇 |
2011年 | 366篇 |
2010年 | 225篇 |
2009年 | 217篇 |
2008年 | 326篇 |
2007年 | 232篇 |
2006年 | 302篇 |
2005年 | 201篇 |
2004年 | 184篇 |
2003年 | 177篇 |
2002年 | 213篇 |
2001年 | 319篇 |
2000年 | 287篇 |
1999年 | 259篇 |
1998年 | 128篇 |
1997年 | 158篇 |
1996年 | 171篇 |
1995年 | 175篇 |
1994年 | 139篇 |
1993年 | 161篇 |
1992年 | 234篇 |
1991年 | 209篇 |
1990年 | 207篇 |
1989年 | 242篇 |
1988年 | 244篇 |
1987年 | 205篇 |
1986年 | 204篇 |
1985年 | 216篇 |
1984年 | 189篇 |
1983年 | 229篇 |
1982年 | 170篇 |
1981年 | 159篇 |
1980年 | 156篇 |
1979年 | 229篇 |
1978年 | 181篇 |
1977年 | 164篇 |
1976年 | 149篇 |
1975年 | 128篇 |
1974年 | 119篇 |
1973年 | 125篇 |
1971年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Five groups of undergraduate students, Dropouts (academic dismissals), Low Stopouts (voluntary leavers with low GPA), Low Persisters (continuing students with low GPA), High Stopouts (voluntary leavers with high GPA), High Persisters (continuing students with high GPA), were compared in terms of their use of various campus facilities and their responses to a checklist of personal problems. The High Stopouts and High Persisters did not differ in use of facilities. However, among the low academic performance students, the Low Persisters made significantly greater use of facilities than the Low Stopouts, who, in turn, made significantly greater use of facilities than Dropouts. These findings, for the most part, did not appear to be related to the self-reported importance of personal problems. It was concluded that among low performance students, the broad use of campus services and facilities can be taken as a measure of student integration in the college community. 相似文献
102.
Anthony A. Wright Robert G. Cook Jacquelyne J. Rivera Stephen F. Sands Juan D. Delius 《Learning & behavior》1988,16(4):436-444
Pigeons were trained to match-to-sample with several new methodologies: a large number of stimuli, computer-drawn color picture stimuli, responses monitored by a computer touch screen, stimuli presented horizontally from the floor, and grain reinforcement delivered onto the picture stimuli. Following acquisition, matching-to-sample concept learning was assessed by transfer to novel stimuli on the first exposure to pairs of novel stimuli. One group (trial-unique), trained with 152 different pictures presented once daily, showed excellent transfer (80% correct). Transfer and baseline performances were equivalent, indicating that the matching-to-sample concept had been learned. A second group (2-stimulus), trained with only two different pictures, showed no evidence of transfer. These results are discussed in terms of the effect of numbers of exemplars on previous failures to find concept learning in pigeons, and the implications of the positive finding from this experiment on abstract concept learning and evolutionary cognitive development. 相似文献
103.
104.
105.
Robert J. Jones Ph.D. Kenneth J. Gruber Ph.D. Gary D. Timbers Ph.D. 《Child abuse & neglect》1981,5(4):431-440
This study reports the results of extensive interviews with an intact sample of moderately delinquent adolescents concerning their sexual assault histories. Findings indicate a surprisingly high incidence of victimization among the females interviewed which, the authors suggest, may characterize the larger population of delinquent females. The behavioral-situational contexts of reported victimization experiences are examined for salient commonalities and the following composite rape scenerio can be cast from the data: An unsupervised, 14-year-old female, who has been consuming alcohol or marijuana, is sexually assaulted, following threat and/or force, to the point of penile-vaginal penetration, by an older male friend or acquaintance (who has also consumed alcohol or marijuana) in his home or vehicle or other place where she is inherently unprotected. Some comments are offered concerning the requirements of an effective technology of child rape prevention. 相似文献
106.
107.
Steven F. Schomberg Darwin D. Hendel Caroline L. Bassett 《Innovative Higher Education》1983,7(2):95-104
This article describes one institution's use of the College Outcome Measures Project (COMP) in comparing outcomes for graduates of traditional and non-traditional programs. The study was designed to answer three questions concerning the use of COMP in evaluating traditional and non-traditional programs. Results obtained in a study of 96 University of Minnesota graduating seniors suggest greater potential usefulness in distinguishing among institutions than in comparing outcomes of programs within an institution. The authors conclude that as new approaches and instruments for measuring college outcomes become available, criteria for instrument selection need to be shared among individuals charged with conducting outcome studies. 相似文献
108.
109.
Cognitive theory suggests that a key to expert performance lies in the internal organization of the expert's knowledge. The authors contend that the type of technical illustration used during instruction influences knowledge organization and greatly impacts students' understanding of the content. This paper describes an experimental study that tested the impact of one type of conceptual illustration on students' understanding of the structure, function, and behavior of complex technical systems. The results show that supplementing traditional technical instruction with functional flow diagrams can improve overall system understanding. The functional flow diagrams were also found to be an effective instructional aid for enhancing students' conceptual understanding of the causal behavior of systems. In addition, the use of the functional flow diagram was found to significantly improve the subjects' ability to construct conceptual models that were similar to those of an expert. The implications of using conceptual diagrams for technical instruction are discussed and recommendations for future research in this area are provided. 相似文献
110.
Mary Jane Feldman Ph.D. 《Research in higher education》1993,34(4):503-512
This study sought to evaluate preenrollment variables as predictors of one-year retention of first-time students in a community college. The purpose was to use information that is typically available when a student begins his or her college program and determine if this information can help identify students who are more likely to drop out within their first year. Based on a logistic regression model to select predictors of retention, the lower the high school GPA, the greater the chance the student will drop out. Over and above this, additional risk is associated with the age range 20–24, attending part-time, and being an ethnic minority other than Asian. When all or some of these are operating, it may be necessary to enhance these students' chances with special programs or services. 相似文献