首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   123128篇
  免费   1919篇
  国内免费   240篇
教育   85386篇
科学研究   13740篇
各国文化   2058篇
体育   9595篇
综合类   175篇
文化理论   1138篇
信息传播   13195篇
  2021年   958篇
  2020年   1706篇
  2019年   2635篇
  2018年   3178篇
  2017年   3500篇
  2016年   3528篇
  2015年   2412篇
  2014年   3295篇
  2013年   28082篇
  2012年   2451篇
  2011年   2802篇
  2010年   2431篇
  2009年   2679篇
  2008年   2482篇
  2007年   2222篇
  2006年   2456篇
  2005年   2433篇
  2004年   3132篇
  2003年   2447篇
  2002年   2234篇
  2001年   2098篇
  2000年   1796篇
  1999年   1662篇
  1998年   1525篇
  1997年   1596篇
  1996年   1753篇
  1995年   1549篇
  1994年   1517篇
  1993年   1507篇
  1992年   1550篇
  1991年   1370篇
  1990年   1334篇
  1989年   1249篇
  1988年   1106篇
  1987年   1060篇
  1986年   1066篇
  1985年   1315篇
  1984年   1182篇
  1983年   1108篇
  1982年   1115篇
  1981年   1035篇
  1980年   980篇
  1979年   1109篇
  1978年   1065篇
  1977年   981篇
  1976年   878篇
  1975年   718篇
  1974年   713篇
  1973年   700篇
  1972年   516篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
991.
The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.  相似文献   
992.
993.
994.
This study examined whether or not activity monitor data collected as part of a typical 7-day physical activity (PA) measurement protocol can be expected to be missing at random. A total of 315 participants (9–18 years) each wore a SenseWear Armband monitor for 7 consecutive days. Participants were classified as “compliant” (86 boys and 124 girls) if they had recorded accelerometer data during 70% or more of the predefined awake time (7 AM–10 PM) on four different days; and “non-compliant” (44 boys and 51 girls) when not meeting these criteria. Linear mixed models were used to examine differences in energy expenditure (EE) levels by compliance across 10 different time periods. The results indicated that non-compliant girls were older (13.4 ± 2.9 vs. 12.2 ± 2.5) and taller (156.8 ± 10.3 vs. 152.8 ± 11.3) than their same gender compliant peers (P < .05). Comparisons of EE rates at segmented portions of the day revealed no differences between compliant and non-compliant groups (P ≥ .05). Differences in EE ranged from ?0.32 kcal · kg?1 · h?1 (before school time) to 0.62 kcal · kg?1 · h?1 (physical education class) in boys and ?0.39 kcal · kg?1 · h?1 (transportation from school) to 0.37 kcal · kg?1 · hour?1 (recess) in girls. The results showed that compliant and non-compliant individuals differed in a few demographic characteristics but exhibited similar activity patterns. This suggests that data were considered to be missing at random, but additional work is needed to confirm this observation in a representative sample of children using other types of activity monitors and protocols.  相似文献   
995.
996.
997.
998.
999.
1000.
The fin de siècle witnessed radical shifts in the intellectual and cultural landscapes of the British Isles in the context of a general revolt against Victorian values. E. E. Fournier d’Albe – physicist, spiritualist, inventor and Pan-Celticist – personified the ability of intellectuals to latch onto and advance new trends, made available by the emergent intellectual pluralism. Like many contemporaries he rejected traditional religion, but he also disdained scientific materialism, and sought a deeper metaphysical meaning to life, pursued through his various interests. Influenced by the totalising theories of figures like Herbert Spencer and Ernst Haeckel, Fournier concocted his own brand of scientific monism, rejecting materialism, embracing spiritualism, and ever optimistic in the notion of scientific progress, even in the wake of the carnage of the Great War. The article aims to give Fournier a fuller historical treatment, allowing his story to add to understanding of the milieus in which he lived and operated, and revealing how his monistic philosophy incorporated some of the disparate cultural strands explored by intellectuals in the fin de siècle reaction against conventional Victorian ideals.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号