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   2465篇
  免费   75篇
  国内免费   4篇
教育   1851篇
科学研究   87篇
各国文化   29篇
体育   189篇
综合类   1篇
文化理论   15篇
信息传播   372篇
  2023年   16篇
  2022年   19篇
  2021年   35篇
  2020年   60篇
  2019年   96篇
  2018年   114篇
  2017年   143篇
  2016年   127篇
  2015年   88篇
  2014年   113篇
  2013年   583篇
  2012年   80篇
  2011年   95篇
  2010年   65篇
  2009年   73篇
  2008年   78篇
  2007年   79篇
  2006年   71篇
  2005年   62篇
  2004年   57篇
  2003年   54篇
  2002年   33篇
  2001年   28篇
  2000年   28篇
  1999年   22篇
  1998年   14篇
  1997年   13篇
  1996年   20篇
  1995年   13篇
  1994年   13篇
  1993年   17篇
  1992年   16篇
  1991年   10篇
  1990年   13篇
  1989年   12篇
  1988年   18篇
  1987年   7篇
  1986年   12篇
  1985年   16篇
  1984年   14篇
  1983年   9篇
  1982年   10篇
  1981年   5篇
  1980年   6篇
  1979年   5篇
  1977年   8篇
  1976年   5篇
  1973年   8篇
  1970年   4篇
  1968年   7篇
排序方式: 共有2544条查询结果,搜索用时 31 毫秒
21.
In 1884, a street corner harangue by the local precinct captain precipitated a torch light parade; the coming of a presidential aspirant caused the whole countryside to erupt. This article presents some of the color, bustle, hysteria, and rhetoric which accompanied James G. Blaine's week‐long but fruitless effort to capture the electoral votes of a crucial state.  相似文献   
22.
The pigments used by the ancient Egyptians constitute the most diverse pigment palette of the ancient world. This review discusses the pigments and binders which were used, arranged principally in terms of the colours themselves, namely, the white, green, grey, black, brown, blue, red, orange, and yellow pigments. The chemical identity of these pigments is discussed with some details regarding the artefacts or time periods from which the pigment concerned has been identified. Combinations of pigments were used for creating some colours, especially: greens, pinks, blues, yellows, and a variety of pale hues by mixing primary colours with a white addition, such as calcite. The identification of ancient Egyptian pigments is often aggravated by chemical interactions between pigment and binder media, or between the pigment and environmental pollutants, or both. The nature of the binders and varnishes used in ancient Egypt is briefly discussed. The identification of green pigments from ancient Egypt is often difficult, and some of the recent research concerning the topic is reviewed. In addition to including relevant details from older literature, this review provides a synopsis of recent studies which have appeared since the last major review carried out by Lee and Quirke in 2000.  相似文献   
23.
24.
This study investigated the acute endocrine responses to a 164-km road cycling event in a hot environment. Thirty-four male experienced cyclists (49.1 ± 8.3 years, 86.8 ± 12.5 kg, 178.1 ± 5.1 cm) participating in a 164-km road cycling event were recruited. Blood samples were collected within 0.3–2.0 h before the start (PRE: ~0500–0700 h) and immediately following the ride (POST). Samples were analysed for testosterone, growth hormone (GH), cortisol and interleukin-6 (IL-6). The temperature and humidity during the event were 35.3 ± 4.9°C and 47.2 ± 14.0%, respectively. Based on the finishing time, results for the fastest (FAST, 305 ± 10 min) and the slowest (SLOW, 467 ± 31 min) quartiles were compared. At POST, testosterone concentration was significantly (P < 0.05) lower (PRE, 20.8 ± 8.6; POST, 18.2 ± 6.7 nmol · L?1), while GH (PRE, 0.3 ± 0.1; POST, 2.3 ± 0.3 µg · L?1), cortisol (PRE, 661 ± 165; POST, 1073 ± 260 nmol · L?1) and IL-6 (PRE, 4.0 ± 3.4; POST, 22.4 ± 15.2 pg · mL?1) concentrations were significantly higher than those at PRE. At POST, GH and cortisol were significantly higher for the FAST group than for the SLOW group (GH, 3.6 ± 2.0 and 1.0 ± 0.8 µg · L?1; cortisol, 1187 ± 209 and 867 ± 215 nmol · L?1). Participation in an ultra-endurance road cycling event in a hot environment induced significant acute changes in concentrations of circulating hormones, with a greater augmentation of GH and cortisol in those completing the ride fastest.  相似文献   
25.
This study examined the skill involvements of three positional groups across a junior representative rugby league season. Data were collected from 45 rugby league players (mean ± SD; age = 16.5 ± 1.0 years) currently participating in the Harold Matthews and SG Ball Cup. Players were subdivided into hit-up forwards, adjustables and outside backs. The frequency (n · min?1) of offensive, defensive and overall involvements was coded for each group using a notation system and a practical coach skill analysis tool. Multivariate analysis of variance (MANOVA) revealed a significant effect of playing position on skill involvements (F = 9.06; P < 0.001; ES = 0.41). Hit-up forwards performed a significantly greater frequency of offensive (0.31 ± 0.10), defensive (0.42 ± 0.15) and overall involvements (0.74 ± 0.19) when compared to adjustables (0.20 ± 0.08, 0.28 ± 0.08 and 0.52 ± 0.15, respectively) and outside backs (0.20 ± 0.12, 0.11 ± 0.07 and ± 0.31 ± 0.17, respectively). Further, adjustables performed a significantly greater number of defensive (0.28 ± 0.08) and overall involvements (0.52 ± 0.15) when compared to outside backs (0.11 ± 0.07 and 0.31 ± 0.17, respectively). The findings of this study suggest that it is important to consider a junior player’s positional group when analysing their skill involvements. Information gained from this study could assist in the design of specific training methodologies for junior rugby league players in high-level talent development programmes.  相似文献   
26.
The purpose of this article was to examine the validity of self-reported pedometer steps/day. Forty-seven participants were provided a New Lifestyles NL-2000 (NL-2000; Lees Summit, MO, USA) pedometer and a physical activity (PA) diary for 3 weeks, but not informed of the data-storing capabilities. For weeks 2 and 3, each participant was given a step goal of 3,000 steps/day above week 1 average. A 2 × 3 repeated measures analysis of variance (ANOVA) was used to examine differences between reported steps/day. Bland–Altman plots assessed the mean bias and limits of agreement between reporting methods. Mean self-reported and NL-2000 steps/day were 9,264 ± 3,555 and 8,971 ± 3,590 steps/day (n = 26, p > .05). Mean biases were 216 ± 1,753 (week 1), –506 ± 1,355 (week 2), and –590 ± 1,360 (week 3) steps/day. Negative mean bias values indicate higher self-reported steps/day. Mean steps/day were similar between recording methods, but large differences were observed among individuals, suggesting self-reported steps/day may be valid for PA research at the population level, but not the individual level.  相似文献   
27.
Limited tools assess positive development through university sport. Such a tool was validated in this investigation using two independent samples of Canadian university athletes. In Study 1, 605 athletes completed 99 survey items drawn from the Youth Experience Scale (YES 2.0), and separate a priori measurement models were evaluated (i.e., 99 items, YES 2.0, YES for Sport [YES-S]). Confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM) results indicated issues with model fit. Post-hoc modifications improved fit, resulting in a 46-item, 9-factor model with five positive and four negative dimensions. In Study 2, 511 athletes completed the same items. The resultant model was confirmed using both CFA (comparative fit index [CFI] = .911, standardized root mean square residual [SRMR] = .056, root mean square error of approximation [RMSEA] = .040) and ESEM (CFI = .956, SRMR = .023, RMSEA = .034). The resultant University Sport Experience Survey provides a reliable and factorially valid instrument for measuring development in university sport.  相似文献   
28.
29.
30.
Early developmental psychologists viewed iconic representation as cognitively less complex than other forms of symbolic thought. It is therefore surprising that iconic signs are not acquired more easily than arbitrary signs by young language learners. One explanation is that children younger than 3 years have difficulty interpreting iconicity. The current study assessed hearing children's ability to interpret the meaning of iconic signs. Sixty-six 2.5- to 5-year-olds who had no previous exposure to signs were required to match iconic signs to pictures of referents. Whereas few of the 2.5-year-olds recognized the meaning of the iconic signs consistently, more than half of the 3.0-year-olds and most of 3.5-year-olds performed above chance. Thus, the ability to recognize the meaning of iconic signs gradually develops during the preschool years. Implications of these findings for sign language development, receptive signed vocabulary tests, and the development of the ability to interpret iconic symbols are discussed.  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