全文获取类型
收费全文 | 1484篇 |
免费 | 23篇 |
专业分类
教育 | 1110篇 |
科学研究 | 105篇 |
各国文化 | 16篇 |
体育 | 63篇 |
综合类 | 2篇 |
文化理论 | 22篇 |
信息传播 | 189篇 |
出版年
2021年 | 15篇 |
2020年 | 27篇 |
2019年 | 40篇 |
2018年 | 40篇 |
2017年 | 58篇 |
2016年 | 49篇 |
2015年 | 30篇 |
2014年 | 45篇 |
2013年 | 412篇 |
2012年 | 37篇 |
2011年 | 43篇 |
2010年 | 40篇 |
2009年 | 33篇 |
2008年 | 32篇 |
2007年 | 32篇 |
2006年 | 26篇 |
2005年 | 26篇 |
2004年 | 24篇 |
2003年 | 23篇 |
2002年 | 23篇 |
2001年 | 15篇 |
2000年 | 25篇 |
1999年 | 24篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 15篇 |
1995年 | 9篇 |
1994年 | 13篇 |
1993年 | 15篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 14篇 |
1983年 | 12篇 |
1982年 | 12篇 |
1981年 | 7篇 |
1980年 | 12篇 |
1979年 | 13篇 |
1978年 | 12篇 |
1977年 | 8篇 |
1975年 | 9篇 |
1973年 | 7篇 |
1972年 | 7篇 |
1968年 | 8篇 |
1940年 | 8篇 |
1933年 | 8篇 |
排序方式: 共有1507条查询结果,搜索用时 15 毫秒
71.
BackgroundIndividuals with diabetes have greater central arterial stiffness, wave reflections, and hemodynamics, all of which promote the accelerated cardiovascular pathology seen in this population. Acute aerobic exercise has been shown to be an effective strategy for reducing central arterial stiffness, wave reflections, and hemodynamics in healthy individuals; however, the effects of acute aerobic exercise in reducing these outcomes is not well established in people with diabetes. Recently, implementation of high-intensity interval exercise (HIIE) has shown superior improvements in cardiovascular health outcomes when compared to traditional aerobic exercise. Yet, the effect of HIIE on the aforementioned outcomes in people with diabetes is not known. The purpose of this study was to (i) describe the central arterial stiffness, wave reflections, and hemodynamic responses to a bout of HIIE and moderate-intensity continuous exercise (MICE) in adults with diabetes; and (ii) compare the effects of HIIE and MICE on the aforementioned outcomes.MethodsA total of 24 adult men and women (aged 29–59 years old) with type 1 (n = 12) and type 2 (n = 12) diabetes participated in a randomized cross-over study. All participants completed the following protocols: (i) HIIE: cycling for 4 × 4 min at 85%–95% of heart rate peak (HRpeak), interspersed with 3 min of active recovery at 60%–70%HRpeak; (ii) MICE: 33 min of continuous cycling at 60%–70%HRpeak; and (iii) control (CON): lying quietly in a supine position for 30 min.ResultsA significant group × time effect was found for changes in central systolic blood pressure (F = 3.20, p = 0.01) with a transient reduction for the HIIE group but not for the MICE or CON groups. There was a significant group × time effect for changes in augmentation index at a heart rate of 75 beats/min (F = 2.32, p = 0.04) with a decrease following for HIIE and MICE but not for CON. For all other measures of central arterial stiffness and hemodynamics, no significant changes were observed (p > 0.05).ConclusionA bout of HIIE appears to lead to a greater transient reduction in central systolic blood pressure than the reduction observed following MICE; however, both HIIE and MICE improved augmentation index at a heart rate of 75 beats/min in people with diabetes. There was no significant difference in response to HIIE and MICE in all outcomes. This provides preliminary evidence on the role of HIIE on such outcomes in people with diabetes. 相似文献
72.
73.
Jenny K. Johnson 《Educational Media International》2013,50(3):125-126
Abstract The purpose of this investigation was to determine the extent to which computers assist high school students in learning English language vocabulary. The experience describes an experimental investigation conducted in a Teacher‐Training Practising Secondary School in Cameroon on the use of computer‐assisted software to teach English vocabulary. Specifically, the major thrust of this investigation was to compare the effects of using computers in the teaching of English language vocabulary with the conventional method of teaching. Students were split into two groups: an experimental group and a control group. The latter group received the conventional method while the former group was given the computer software application. Results indicated that there was very little significant difference in the academic performance of both groups. However, the experimental group demonstrated positive attitudes toward a computer and the software program. Abstract français: Le but de cette recherche était de déterminer jusqu'o[ugrave] les ordinateurs peuvent aider des étudiants d'école secondaire à apprendre le vocabulaire anglais. L'article décrit la recherche conduite dans un institut de formation des maîtres du second degré au Cameroun sur l'utilisation de logiciels pour l'enseignement du vocabulaire anglais. En fait, l'objectif majeur de cette recherche était de comparer les effets de l'emploi des ordinateurs à cette fin avec les méthodes traditionelles de formation. On a divisé les étudiants en deux groupes: expérimental et contrôle. Ce dernier a reçu cette formation traditionelle, tandis que le premier a subi des applications de logiciels. Les résultats ont montré qu'il n'y avait pas de différence significative entre les performances des deux groupes. Cependant, le groupe expérimental a fait preuve d'attitudes positives envers l'ordinateur et les programmes de logiciels. 相似文献
74.
75.
76.
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
77.
The aim of this study was to determine the level of awareness of methodological search filters among health and academic librarians in the UK and Ireland, their use of filters and views on the perceived benefits, limitations and ways to increase usage of search filters. A random proportional sample of health and academic librarians were surveyed by telephone and fax. Overall, 88% (196/224) completed the telephone survey to establish awareness and use of filters. Eighty-four per cent (51/61) completed a fax survey focusing in more depth on usability issues surrounding filters. Results indicate a high level of awareness of methodological filters, but low level of usage. Furthermore, a high level of awareness did not necessarily correlate with a high level of knowledge or understanding. Examination of responses revealed limitations and recommendations beyond those reported in the literature and highlights the relationship between understanding and effective use of filters. Improved dissemination and publication of filters is required to better inform librarians on the concept of filters and how to use them effectively. 相似文献
78.
In May 2002, the Denison Memorial Library at the University of Colorado Health Sciences Center and the J. Otto Lottes Health Sciences Library at the University of Missouri-Columbia, with funding from the National Network of Libraries of Medicine-Midcontinental Region, embarked on a collaborative, real-time reference project using the 24/7 Reference, Inc., software package. This paper describes how the project was conceived, and includes details on the service hours, staffing, training, marketing, lessons learned, and future plans for the service. 相似文献
79.
Johnson MH 《Child development》2000,71(1):75-81
One future direction for cognitive development research involves a closer integration with our knowledge about the developing brain. I present a framework for analyzing and interpreting postnatal functional brain development in human infants. Three specific hypotheses contribute to this framework, within which a variety of phenomena associated with the neural basis of perception and cognition in normal and abnormal development can be characterized. 相似文献
80.