全文获取类型
| 收费全文 | 14987篇 |
| 免费 | 219篇 |
| 国内免费 | 119篇 |
专业分类
| 教育 | 10177篇 |
| 科学研究 | 2033篇 |
| 各国文化 | 110篇 |
| 体育 | 1369篇 |
| 综合类 | 11篇 |
| 文化理论 | 120篇 |
| 信息传播 | 1505篇 |
出版年
| 2021年 | 106篇 |
| 2020年 | 212篇 |
| 2019年 | 312篇 |
| 2018年 | 427篇 |
| 2017年 | 374篇 |
| 2016年 | 386篇 |
| 2015年 | 244篇 |
| 2014年 | 317篇 |
| 2013年 | 2639篇 |
| 2012年 | 300篇 |
| 2011年 | 337篇 |
| 2010年 | 242篇 |
| 2009年 | 241篇 |
| 2008年 | 256篇 |
| 2007年 | 290篇 |
| 2006年 | 276篇 |
| 2005年 | 271篇 |
| 2004年 | 257篇 |
| 2003年 | 250篇 |
| 2002年 | 238篇 |
| 2001年 | 256篇 |
| 2000年 | 272篇 |
| 1999年 | 274篇 |
| 1998年 | 144篇 |
| 1997年 | 148篇 |
| 1996年 | 175篇 |
| 1995年 | 152篇 |
| 1994年 | 118篇 |
| 1993年 | 126篇 |
| 1992年 | 198篇 |
| 1991年 | 197篇 |
| 1990年 | 217篇 |
| 1989年 | 239篇 |
| 1988年 | 186篇 |
| 1987年 | 212篇 |
| 1986年 | 203篇 |
| 1985年 | 226篇 |
| 1984年 | 200篇 |
| 1983年 | 197篇 |
| 1982年 | 158篇 |
| 1981年 | 147篇 |
| 1980年 | 132篇 |
| 1979年 | 227篇 |
| 1978年 | 170篇 |
| 1977年 | 165篇 |
| 1976年 | 129篇 |
| 1975年 | 124篇 |
| 1974年 | 140篇 |
| 1973年 | 121篇 |
| 1971年 | 113篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
41.
The purpose of this investigation was to describe the morphological parameters that characterize elite age group divers. Comparisons are made to normative age group data from the Coquitlam Growth Study and the constancy of important characteristics from age group to age group is examined. Data were collected on 27 male and 28 female elite divers who participated in the 1990 North American Age Group Diving Championships. Body build, body composition and skinfold corrected diameters were determined from 36 anthropometric parameters and analysed by ANOVA, t-test and Phantom z-scores procedures. All age groups except the 14- to 15-year-old males were significantly (P < or = 0.05) shorter than their norms but recorded higher androgyny index values. The estimated relative muscle mass increased significantly (P < or = 0.05) with age for males at all ages (40.8-46.3%). The 16- to 18-year-old females had a significantly (P < or = 0.05) larger relative muscle component compared to the younger age groups (40.1-38.4%). When normalized for height, active tissue development of the extremities was comparable between the sexes except in the forearm. The results indicate that at all age levels short stature is an important characteristic for divers. Analysis of regional active tissue development provides further insight into sport-specific prerequisites for success at elite levels. 相似文献
42.
43.
44.
45.
46.
E. R. Sukiasyan 《Scientific and Technical Information Processing》2008,35(1):55-61
This paper considers the background of the Library-Bibliographic Classification as the national classification system of Russia, and its history and application in the USSR. It gives the general characteristic of the LBC structure, content and system of designations, as well as the state of its present updating. 相似文献
47.
49.
50.