全文获取类型
收费全文 | 2498篇 |
免费 | 18篇 |
国内免费 | 19篇 |
专业分类
教育 | 1368篇 |
科学研究 | 369篇 |
各国文化 | 3篇 |
体育 | 548篇 |
综合类 | 25篇 |
文化理论 | 5篇 |
信息传播 | 217篇 |
出版年
2024年 | 7篇 |
2023年 | 5篇 |
2022年 | 6篇 |
2016年 | 10篇 |
2015年 | 5篇 |
2014年 | 19篇 |
2013年 | 23篇 |
2012年 | 181篇 |
2011年 | 272篇 |
2010年 | 92篇 |
2009年 | 20篇 |
2008年 | 166篇 |
2007年 | 158篇 |
2006年 | 186篇 |
2005年 | 150篇 |
2004年 | 135篇 |
2003年 | 133篇 |
2002年 | 122篇 |
2001年 | 84篇 |
2000年 | 79篇 |
1999年 | 75篇 |
1998年 | 21篇 |
1997年 | 28篇 |
1996年 | 17篇 |
1995年 | 22篇 |
1994年 | 26篇 |
1993年 | 28篇 |
1992年 | 29篇 |
1991年 | 29篇 |
1990年 | 26篇 |
1989年 | 42篇 |
1988年 | 17篇 |
1987年 | 27篇 |
1986年 | 34篇 |
1985年 | 32篇 |
1984年 | 19篇 |
1983年 | 21篇 |
1982年 | 26篇 |
1981年 | 16篇 |
1979年 | 6篇 |
1960年 | 5篇 |
1959年 | 11篇 |
1958年 | 9篇 |
1957年 | 9篇 |
1956年 | 11篇 |
1955年 | 9篇 |
1954年 | 10篇 |
1951年 | 5篇 |
1948年 | 4篇 |
1937年 | 4篇 |
排序方式: 共有2535条查询结果,搜索用时 15 毫秒
101.
Christensen CL Payne VG Wughalter EH Yan JH Henehan M Jones R 《Research quarterly for exercise and sport》2003,74(2):136-142
This research examined varying levels of physical activity and psychomotor and physiological function in variously active older men. Very active moderately active, and low active participants were tested on simple (SRT) and choice reaction time (CRT), coincidence-anticipation timing (CAT), and VO2max. No significant differences for age or height were found, although percentage of fat, and weight were statistically different. Active groups were leaner and lighter. VO2max was significantly different between groups, as physically active groups yielded geater values. SRT and CAT also yielded significantly different results with more active participants showing better performance. No between-groups significant differences resulted for CRT. Generally, increased levels of physical activity were related to superior physiological outcomes and improved psychomotor peformance. 相似文献
102.
103.
104.
Stone ME Foxman C Sostack M Francar L Hall P Markwell LG 《Medical reference services quarterly》2003,22(2):93-105
The librarians at four hospital libraries describe the electronic reference service, "Ask A Librarian," offered at their institutions. The hospitals are vastly different in size and in number of library staff, and offer the "Ask A Librarian" service to different clientele. The article illustrates that both large hospitals with a large library staff and small hospitals with a solo librarian and some volunteers can offer this type of service. 相似文献
105.
106.
The aim of this study was to determine the influence of type of warm-up on metabolism and performance during high-intensity exercise. Eight males performed 30 s of intense exercise at 120% of their maximal power output followed, 1 min later, by a performance cycle to exhaustion, again at 120% of maximal power output. Exercise was preceded by active, passive or no warm-up (control). Muscle temperature, immediately before exercise, was significantly elevated after active and passive warm-ups compared to the control condition (36.9 +/- 0.18 degrees C, 36.8 +/- 0.18 degrees C and 33.6 +/- 0.25 degrees C respectively; mean +/- sx) (P< 0.05). Total oxygen consumption during the 30 s exercise bout was significantly greater in the active and passive warm-up trials than in the control trial (1017 +/- 22, 943 +/- 53 and 838 +/- 45 ml O2 respectively). Active warm-up resulted in a blunted blood lactate response during high-intensity exercise compared to the passive and control trials (change = 5.53 +/- 0.52, 8.09 +/- 0.57 and 7.90 +/- 0.38 mmol x l(-1) respectively) (P < 0.05). There was no difference in exercise time to exhaustion between the active, passive and control trials (43.9 +/- 4.1, 48.3 +/- 2.7 and 46.9 +/- 6.2 s respectively) (P= 0.69). These results indicate that, although the mechanism by which muscle temperature is elevated influences certain metabolic responses during subsequent high-intensity exercise, cycling performance is not significantly affected. 相似文献
107.
108.
The aim of this study was to assess the influence of three imposed crank rates on the attainment of peak oxygen consumption (VO2peak) and other physiological responses during incremental arm crank ergometry. Twenty physically active, although non-specifically trained, males volunteered for the study. They completed an exercise protocol using an electrically braked arm ergometer (Lode Angio, Groningen, Netherlands) at crank rates of 60, 70 and 80 rev x min(-1). The order of tests was randomized and they were separated by at least 2 days. Peak VO2 was significantly higher (P < 0.05) at 70 and 80 rev x min(-1) than at 60 rev x min(-1). Peak ventilation volume increased as a function of crank rate and was higher (P < 0.05) at 80 than at 60 rev x min(-1). Peak heart rate was higher (P < 0.05) at 70 and 80 rev x min(-1) than at 60 rev x min(-1). Furthermore, 70 and 80 rev x min(-1) resulted in an extended test time compared with 60 rev x min(-1). The greater physiological responses observed during the tests at the two faster crank rates might have been the result of a postponement of acute localized neuromuscular fatigue, allowing for more work to be completed. We recommend, therefore, that an imposed crank rate between 70 and 80 rev x min(-1) should be used to elicit VO2peak and other physiological responses in arm crank ergometry. 相似文献
109.
Because it is widely accepted that providing information online will play a major role in both the teaching and practice of medicine in the near future, a short formal course of instruction in computer skills was proposed for the incoming class of students entering medical school at the State University of New York at Stony Brook. The syllabus was developed on the basis of a set of expected outcomes, which was accepted by the dean of medicine and the curriculum committee for classes beginning in the fall of 1997. Prior to their arrival, students were asked to complete a self-assessment survey designed to elucidate their initial skill base; the returned surveys showed students to have computer skills ranging from complete novice to that of a systems engineer. The classes were taught during the first three weeks of the semester to groups of students separated on the basis of their knowledge of and comfort with computers. Areas covered included computer basics, e-mail management, MEDLINE, and Internet search tools. Each student received seven hours of hands-on training followed by a test. The syllabus and emphasis of the classes were tailored to the initial skill base but the final test was given at the same level to all students. Student participation, test scores, and course evaluations indicated that this noncredit program was successful in achieving an acceptable level of comfort in using a computer for almost all of the student body. 相似文献
110.
It has previously been shown that females incur less muscle damage than males after strenuous exercise, but limited data are available for humans. To determine possible differences between the sexes in humans, the response to high-force eccentric exercise was examined in a large sample of women (n = 83) and men (n = 82). The participants performed a bout of eccentric exercise of the elbow flexors consisting of 70 maximal repetitions. Isometric strength, resting elbow angle and muscle soreness were measured before, immediately after (except soreness) and then daily for 7 days after exercise. There was a significant loss in strength among both groups (69% for women and 63% for men) (P < 0.01) immediately after exercise; at 168 h post-exercise, women still had a 27% strength loss and men had a 24% strength loss. No significant difference in strength loss or recovery rate was found between men and women. Soreness reached peak values 32-48 h post-exercise (P < 0.01), with no significant difference between men and women. Range of motion decreased significantly until 3 days after exercise (14.6 degrees or 0.255 rad loss for women; 12.2 degrees or 0.213 rad loss for men) (P < 0.01); at 168 h post-exercise, the women and men still showed a loss of 4.8 degrees (0.084 rad) and 4.0 degrees (0.07 rad), respectively. There was a significant interaction of sex x time (P < 0.01); a post-hoc test indicated that the women experienced a greater loss in range of motion at 72 h than men and this difference was maintained to 168 h post-exercise (P < 0.01). Thus, our results do not support the contention that women have a lower response to eccentric exercise than men. 相似文献