全文获取类型
收费全文 | 21788篇 |
免费 | 276篇 |
国内免费 | 29篇 |
专业分类
教育 | 14930篇 |
科学研究 | 2595篇 |
各国文化 | 199篇 |
体育 | 1875篇 |
综合类 | 22篇 |
文化理论 | 250篇 |
信息传播 | 2222篇 |
出版年
2021年 | 199篇 |
2020年 | 312篇 |
2019年 | 432篇 |
2018年 | 610篇 |
2017年 | 648篇 |
2016年 | 565篇 |
2015年 | 385篇 |
2014年 | 551篇 |
2013年 | 3746篇 |
2012年 | 499篇 |
2011年 | 486篇 |
2010年 | 452篇 |
2009年 | 404篇 |
2008年 | 426篇 |
2007年 | 462篇 |
2006年 | 419篇 |
2005年 | 369篇 |
2004年 | 386篇 |
2003年 | 372篇 |
2002年 | 365篇 |
2001年 | 447篇 |
2000年 | 471篇 |
1999年 | 382篇 |
1998年 | 202篇 |
1997年 | 247篇 |
1996年 | 258篇 |
1995年 | 188篇 |
1994年 | 220篇 |
1993年 | 197篇 |
1992年 | 334篇 |
1991年 | 312篇 |
1990年 | 335篇 |
1989年 | 327篇 |
1988年 | 280篇 |
1987年 | 292篇 |
1986年 | 291篇 |
1985年 | 332篇 |
1984年 | 248篇 |
1983年 | 246篇 |
1982年 | 223篇 |
1981年 | 206篇 |
1980年 | 198篇 |
1979年 | 328篇 |
1978年 | 227篇 |
1977年 | 215篇 |
1976年 | 190篇 |
1975年 | 166篇 |
1974年 | 173篇 |
1973年 | 148篇 |
1971年 | 152篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Facebook is challenging professional journalism. These challenges were evident in three incidents from 2016: the allegation that Facebook privileged progressive-leaning news on its trending feature; Facebook’s removal of the Pulitzer Prize-winning “Napalm Girl” photo from the pages of prominent users; and the proliferation of “fake news” during the US presidential election. Using theoretical concepts from the field of boundary work, this paper examines how The Guardian, The New York Times, Columbia Journalism Review and Poynter editorialized Facebook’s role in these three incidents to discursively construct the boundary between the value of professional journalism to democracy and Facebook’s ascendant role in facilitating essential democratic functions. Findings reveal that these publications attempted to define Facebook as a news organization (i.e., include it within the boundaries of journalism) so that they could then criticize the company for not following duties traditionally incumbent upon news organizations (i.e., place it outside the boundaries of journalism). This paper advances scholarship that focuses on both inward and outward conceptions of boundary work, further explores the complex challenge of defining who a journalist is in the face of rapidly changing technological norms, and advances scholarship in the field of media ethics that positions ethical analysis at the institutional level. 相似文献
72.
73.
74.
75.
Eisenhauer ER Mosher EC Lamson KS Wolf HA Schwartz DG 《Health information and libraries journal》2012,29(2):152-161
Background: Somali Bantu refugees, with unique health information needs, created challenges for health and social service providers. Objectives: A service innovation was developed (i) to raise awareness, especially among local health and social service providers, about the Bantu refugees’ presence in the community, their culture, and their information needs and (ii) to deliver needed health information, emphasizing child health, to the Bantu mothers in their homes. Methods: The project consisted of: (i) a community conference targeting local health and social service providers, describing the refugees’ presence in the community, their culture, and information needs. (ii) Focus groups conducted with members of the Bantu population elicited additional information needs. (iii) Curriculum was developed based on identified needs, and (iv) the curriculum was delivered to the refugees in their homes. A clinical informationist and MP3 technology enhanced the project. Findings: Conference attendees’ evaluation responses indicated improved understanding of Bantu culture. Focus groups’ identification of health information needs provided a framework for the health education curriculum. A project website made educational materials available to other healthcare providers. Conclusions: The project raised awareness of the Bantus’ presence, culture, and information needs. Identification of other unmet needs demonstrated that additional support for refugees is required. 相似文献
76.
Miller LE Pierson LM Nickols-Richardson SM Wootten DF Selmon SE Ramp WK Herbert WG 《Research quarterly for exercise and sport》2006,77(1):58-63
This study assessed muscular torque and rate of torque development following concentric (CON) or eccentric (ECC) isokinetic training. Thirty-eight women were randomly assigned to either CON or ECC training groups. Training consisted of knee extension and flexion of the nondominant leg three times per week for 20 weeks (SD = 1). Eccentric training increased ECC knee extension and flexion peak torque more than CON training. The ECC group improved acceleration time and time to peak torque with ECC movements versus the CON group. Slow-velocity ECC isokinetic training yielded greater ECC and similar CON torque development gains versus CON training over the course of 20 weeks in young women. 相似文献
77.
Perception of kinematic characteristics of tennis strokes for anticipating stroke type and direction
The purpose of this study was to determine the sources of visual information used by highly skilled tennis players in anticipating their opponent's shots. In Experiment 1, motion analysis of the strokes showed that the relative motion between the racquet and forearm was different between the ground strokes and lobs, but there were no reliable kinematic differences when shot direction was varied. In Experiment 2, 12 skilled tennis players observed the opponent hitting strokes in a normal video or in a point-light display with different segments occluded. Players' anticipation accuracy was not degraded by the use of the point-light display. Occluding the racquet and forearm significantly reduced the participant's ability to determine the type of stroke produced. 相似文献
78.
Myers ND Wolfe EW Maier KS Feltz DL Reckase MD 《Research quarterly for exercise and sport》2006,77(4):451-463
This study extended validity evidence for multidimensional measures of coaching competency derived from the Coaching Competency Scale (CCS; Myers, Feltz, Maier, Wolfe, & Reckase, 2006) by examining use of the original rating scale structure and testing how measures related to satisfaction with the head coach within teams and between teams. Motivation, game strategy, technique, and character building comprised the dimensions of coaching competency. Data were collected from athletes (N = 585) nested within intercollegiate men's (g = 8) and women's (g = 13) soccer and women's ice hockey (g = 11) teams (G = 32). Validity concerns were observed for the original rating scale structure and the predicted positive relationship between motivation competency and satisfaction with the coach between teams. Validity evidence was offered for a condensed post hoc rating scale and the predicted relationship between motivation competency and satisfaction with the coach within teams. 相似文献
79.
Efthimiadou A Asimakopoulos B Nikolettos N Giatromanolaki A Sivridis E Lialiaris TS Papachristou DN Kontoleon E 《Journal of sports sciences》2006,24(8):849-854
Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischaemic diseases, there are still many unanswered questions, including the method of administration, the correct dose of these factors, and the duration of the therapeutic approach. Exercise has also been suggested to induce neovascularizaiton in muscles. We evaluated the angiogenetic effects of the intramuscular administration of basic-fibroblast growth factor (b-FGF) and acidic-fibroblast growth factor (a-FGF) in rat heart, compared with rats who exercised daily. In conclusion, both the intramuscular administration of b-FGF and exercise increased significantly angiogenesis in the heart in contrast to the intramuscular administration of a-FGF, which was ineffective. 相似文献
80.
The graph-theoretic field model— II. application of multi-terminal representations to field problems
This paper is a sequel to a paper entitled “The Graph-Theoretic Field Model—I: Modelling and Formulations” (1). Herein, the Theory of Multi-Terminal Representations is applied to the Graph-Theoretic Field Model to provide mathematical models of finite elements. The element models are obtained solely from the algebraic building blocks of the Graph-Theoretic Field Model, without recourse to any functional mathematics. The theory of Multi-Terminal Representations is developed for both linear and non-linear problems. Examples of the application of the theory to one- and two-dimensional field problems are presented from heat conduction and electrostatics. 相似文献