全文获取类型
收费全文 | 429篇 |
免费 | 17篇 |
专业分类
教育 | 333篇 |
科学研究 | 21篇 |
各国文化 | 7篇 |
体育 | 48篇 |
文化理论 | 2篇 |
信息传播 | 35篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 11篇 |
2019年 | 15篇 |
2018年 | 30篇 |
2017年 | 19篇 |
2016年 | 31篇 |
2015年 | 17篇 |
2014年 | 21篇 |
2013年 | 87篇 |
2012年 | 13篇 |
2011年 | 16篇 |
2010年 | 10篇 |
2009年 | 11篇 |
2008年 | 11篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1989年 | 2篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1971年 | 2篇 |
1967年 | 3篇 |
1965年 | 2篇 |
1964年 | 2篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1935年 | 1篇 |
1921年 | 1篇 |
1880年 | 1篇 |
1875年 | 1篇 |
1860年 | 1篇 |
排序方式: 共有446条查询结果,搜索用时 15 毫秒
311.
312.
313.
314.
Fleming JJ Janardhan HP Jose A Selvakumar R 《Indian journal of clinical biochemistry : IJCB》2011,26(1):32-40
In the present study, the cause of suspected false-positive (anomalous) values for CK-MB activity, in Indian patients investigated
for ACS. Total serum CK and CK-MB activity, serum Troponin I were measured and CK-MB as a percentage of the total CK activity
(%CK-MB) calculated. CK-MB was also estimated using densitometry and CK-MB mass assay. Anomalous specimens were tested for
the presence of CK isoenzymes. In 22 healthy subjects, 11 male and female, the %CK-MB ranged from 3.6 to 30.2. In 11 male
patients, with proven ACS, the %CK-MB was from 4.0 to 17.5. The cut off for anomalous CK-MB activity values was set as >33.0%.
In 35 patients with anomalies, total CK values ranged from 39 to 231 U/L, CK-MB from 30 to 161 U/L. Investigation of CK isoenzymes,
showed 10 patients had a CK-BB band, 14 an intermediate band between CK-MM and CK-MB (macro-CK type 1), 7 had a cathodal band
(macro-CK type 2), and 3 had a band intermediate between CK-MB and CK-BB. This later band does not seem to have been previously
reported. Against the CK-MB mass assay, the activity assay showed no correlation, in 43 patients (19 M, 24 F), Pearson coefficient
(R2) was 0.006. The CK-MB immunoinhibition assay is better described as measuring “non-CK-MM activity.” A %CK-MB activity >6%
as a marker of ACS is not valid in our patient population. Laboratories should not use only CK-MB activity as a biochemical
marker of ACS. 相似文献
315.
This essay explores the growth of boxing among the African populations on the Witwatersrand region of South Africa between 1924 and 1959. It details how the sport's jump in popularity with Africans paralleled migration to Johannesburg. Africans increasingly saw boxing as an activity and skill conducive with survival in this new environment, and thus the sport grew in popularity, stature, and skill-level amongst this emergent urban population. The essay further explores the various ways that the sport was disseminated and popularized during the era, thus detailing how the sport reached both the African masses and petit-bourgeois educated elite. As their presence in Johannesburg became more and more permanent, boxing came to encompass various meanings and ideals, such as notions of discipline, independence and civility, to these urban populations. 相似文献
316.
David Fleming 《Curator: The Museum Journal》2012,55(3):251-256
317.
Elizabeth Brock Clare Milner Xuan Liu James T. Brosnan John C. Sorochan 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(4):362-379
Multiple playing surfaces and footwear used in American football warrant a better understanding of relationship between different combinations of turf and footwear. The purpose of this study was to examine effects of shoe and stud types on ground reaction force (GRF) and ankle and knee kinematics of a 180° cut and a single-leg 90° land-cut on synthetic turf. Fourteen recreational football players performed five trials of the 180° cut and 90° land-cut in three shoe conditions: non-studded running shoe, and football shoe with natural and synthetic turf studs. Variables were analyzed with a 3 × 2 (shoe × movement) repeated measures analysis of variance (p < 0.05). Peak vertical GRF (p < 0.001) and loading rate (p < 0.001) were greater during 90° land-cut than 180° cut. For 180° cut, natural turf studs produced smaller peak medial GRFs compared to synthetic turf studs and non-studded shoe (p = 0.012). For land-cut, peak eversion velocity was reduced in running shoes compared to natural (p = 0.016) and synthetic (p = 0.002) turf studs. The 90° land-cut movement resulted in greater peak vertical GRF and loading rate compared to the 180° cut. Overall, increased GRFs in the 90° land-cut movement may increase the chance of injury. 相似文献
318.
β-alanine is a common ingredient in supplements consumed by athletes. Indeed, athletes may believe that the β-alanine induced paresthesia, experienced shortly after ingestion, is associated with its ergogenic effect despite no scientific mechanism supporting this notion. The present study examined changes in cycling performance under conditions of β-alanine induced paresthesia. Eight competitive cyclists (VO2max = 61.8 ± 4.2 mL·kg·min?1) performed three practices, one baseline and four experimental trials. The experimental trials comprised a 1-km cycling time trial under four conditions with varying information (i.e., athlete informed β-alanine or placebo) and supplement content (athlete received β-alanine or placebo) delivered to the cyclist: informed β-alanine/received β-alanine, informed placebo/received β-alanine, informed β-alanine/received placebo and informed placebo/received placebo. Questionnaires were undertaken exploring the cyclists’ experience of the effects of the experimental conditions. A possibly likely increase in mean power was associated with conditions in which β-alanine was administered (±95% CL: 2.2% ± 4.0%), but these results were inconclusive for performance enhancement (p = 0.32, effect size = 0.18, smallest worthwhile change = 56% beneficial). A possibly harmful effect was observed when cyclists were correctly informed that they had ingested a placebo (–1.0% ± 1.9%). Questionnaire data suggested that β-alanine ingestion resulted in evident sensory side effects and six cyclists reported placebo effects. Acute ingestion of β-alanine is not associated with improved 1-km TT performance in competitive cyclists. These findings are in contrast to the athlete’s “belief” as cyclists reported improved energy and the ability to sustain a higher power output under conditions of β-alanine induced paresthesia. 相似文献
319.
320.
Evren Bay Sengul Sarah C. Emery Cheryl Torok Fleming Lacy Hartman Cara B. Stone 《Public Library Quarterly》2013,32(4):352-362
This research compares the fifty top-rated movies for 2000–2009 recommended by the Internet Movie Database (IMDb) with the holdings of ten medium-sized public libraries. The study shows that there was no relation between a movie's rank in the IMDb listing and the number of copies held. Relationships appeared between number of library holdings and country of production (U.S. productions favored), genre (family, sci-fi, animation, adventure favored), and Motion Picture Association of America (MPAA) rating (G, PG, PG-13 preferred). Library holdings seem to reflect preferences of IMDb raters aged 30 and older, not popular movie tastes. 相似文献