全文获取类型
收费全文 | 24226篇 |
免费 | 329篇 |
国内免费 | 61篇 |
专业分类
教育 | 17438篇 |
科学研究 | 2190篇 |
各国文化 | 216篇 |
体育 | 1725篇 |
综合类 | 45篇 |
文化理论 | 129篇 |
信息传播 | 2873篇 |
出版年
2021年 | 269篇 |
2020年 | 350篇 |
2019年 | 507篇 |
2018年 | 760篇 |
2017年 | 774篇 |
2016年 | 718篇 |
2015年 | 466篇 |
2014年 | 685篇 |
2013年 | 4596篇 |
2012年 | 631篇 |
2011年 | 672篇 |
2010年 | 576篇 |
2009年 | 557篇 |
2008年 | 604篇 |
2007年 | 557篇 |
2006年 | 557篇 |
2005年 | 501篇 |
2004年 | 407篇 |
2003年 | 363篇 |
2002年 | 347篇 |
2001年 | 523篇 |
2000年 | 449篇 |
1999年 | 398篇 |
1998年 | 239篇 |
1997年 | 273篇 |
1996年 | 263篇 |
1995年 | 207篇 |
1994年 | 238篇 |
1993年 | 200篇 |
1992年 | 350篇 |
1991年 | 312篇 |
1990年 | 330篇 |
1989年 | 344篇 |
1988年 | 286篇 |
1987年 | 269篇 |
1986年 | 283篇 |
1985年 | 276篇 |
1984年 | 254篇 |
1983年 | 249篇 |
1982年 | 189篇 |
1981年 | 202篇 |
1980年 | 186篇 |
1979年 | 283篇 |
1978年 | 216篇 |
1977年 | 170篇 |
1976年 | 168篇 |
1975年 | 156篇 |
1974年 | 157篇 |
1973年 | 154篇 |
1971年 | 152篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
N. M. Builova V. S. Egorov O. V. Kirillova L. M. Koroleva T. A. Pronina N. S. Soloshenko 《Scientific and Technical Information Processing》2007,34(6):301-304
The pilot issue of the data collection of the All-Russian Institute of Scientific and Technical Information of the Russian Academy of Sciences “Industry of Nanosystems and Nanomaterials” gives an approximate view of the state of this field of science at the beginning of 2007. The topics of articles in the pilot issue are analyzed. The directions of development of nanotechnologies are shown. The basic types of nanomaterials, the methods of their production, and their properties and applications are given. 相似文献
932.
Information asymmetry and information sharing 总被引:1,自引:0,他引:1
Gavin Clarkson Trond E. Jacobsen Archer L. Batcheller 《Government Information Quarterly》2007,24(4):827
Although much digital divide research focuses on access to technology, another cause of the divide is the lack of information awareness that we call information asymmetry. Information asymmetry often stems from inadequate information sharing and can result in negative consequences for both the information poor and the information rich. Information asymmetry has been insufficiently studied as a possible cause of underdevelopment and inequality. In response, we develop a typology to classify information asymmetry into two categories, horizontal and vertical, and then identify those information sharing practices that cause the imbalance. To illustrate the negative consequences of information asymmetry and the potential benefits of information sharing, we discuss two examples from the experiences of modern American Indian tribes. First, Indian tribes face horizontal information asymmetry when they attempt to access the capital markets, and second, they face vertical information asymmetry in terms of law enforcement data sharing. This article also describes our ongoing examination of horizontal information sharing among tribes and vertical information sharing between tribes and others sovereigns in the American polity as possible solutions to the problems created by information asymmetry. These strategic responses are embodied in two information systems, the Tribal Financial Information Clearinghouse and an Intergovernmental Tracking System for sharing law enforcement data. We conclude with a discussion of how our typology can be more generally applied to other instances of information asymmetry. 相似文献
933.
Jane Fedorowicz Janis L. Gogan Christine B. Williams 《Government Information Quarterly》2007,24(4):785
It is increasingly important for government agencies to collaborate across jurisdictional and functional boundaries. Interorganizational systems supporting interagency collaboration must accommodate a wide range of factors from the external environment and participating organizations as part of their design and operation. This paper presents the findings from a case study of CapWIN, a collaborative network created to enable first responders to share information across jurisdictional and functional boundaries as they work together during emergencies and other critical events. The study examines how aspects of the external environment and the agency context impeded or facilitated the CapWIN collaborative network and the interorganizational system (IOS) that supports it. We identify factors affecting information sharing and collaborative processes, and describe how these factors interact to enable and constrain an IOS. The paper concludes with suggestions for further research on the interplay of environmental, organizational, and technical aspects of interagency collaboration networks as they evolve over time. 相似文献
934.
935.
936.
937.
Sallis JF Calfas KJ Nichols JF Sarkin JA Johnson MF Caparosa S Thompson S Alcaraz JE 《Research quarterly for exercise and sport》1999,70(1):1-10
Project GRAD (Graduate Ready for Activity Daily) evaluates a university course to promote physical activity. In a randomized study, 338 university seniors participated in either an intervention or control course for academic credit, and posttest data were collected on 321. The control course was knowledge-oriented. The intervention course taught behavior change skills in weekly lectures and peer-led labs. Physical activity was assessed with 7-Day Physical Activity Recall interviews. The intervention had no significant effects on men. Among women, the intervention increased total physical activity during leisure, strengthening exercises, and flexibility exercise. This university course had the intended effects of promoting healthful patterns of physical activity among women, but no effects were observed on men, who were more active than women at baseline. 相似文献
938.
Collective efficacy is an important determinant of the motivation of individuals within groups, with increases in collective efficacy producing more effort in a task and greater persistence when faced with failure. To test hypotheses concerning the impact of collective efficacy on effort and persistence, participants (n = 22) were assigned to triads (consisting of the participant and two confederates) and performed three time trials on cycle ergometers. After trial 1, the participants were assigned to either a high or low collective efficacy condition, receiving appropriate bogus performance feedback. All groups received failure feedback after trial 2. Effort was assessed by performance time and maximum heart rate (HRmax) achieved during performance. A 2 (collective efficacy condition) x 3 (trials) analysis of variance with repeated measures on trials revealed significant interaction effects for both performance time and HRmax. Fisher's least significant difference post-hoc tests indicated that, following efficacy manipulation, groups low in collective efficacy significantly reduced both their performance time and HRmax, whereas groups high in collective efficacy maintained performance and HRmax. However, predictions concerning the impact of failure on persistence were not supported. Our results provide partial support for the role of collective efficacy in team sports. 相似文献
939.
Shams ML 《Medical reference services quarterly》1999,18(2):63-80
All living organisms are affected by natural or induced modifications of their surrounding physical environment. A distinct relationship exists between the health of the environment and the health of the individuals living in it. This paper presents a selection of resources about environmental health resources readily accessible on the Internet in October 1998. 相似文献
940.