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   614篇
  免费   12篇
教育   462篇
科学研究   38篇
各国文化   11篇
体育   55篇
文化理论   17篇
信息传播   43篇
  2024年   1篇
  2023年   4篇
  2022年   13篇
  2021年   24篇
  2020年   34篇
  2019年   25篇
  2018年   35篇
  2017年   46篇
  2016年   37篇
  2015年   30篇
  2014年   32篇
  2013年   108篇
  2012年   31篇
  2011年   34篇
  2010年   19篇
  2009年   12篇
  2008年   20篇
  2007年   14篇
  2006年   18篇
  2005年   5篇
  2004年   5篇
  2003年   6篇
  2002年   10篇
  2001年   3篇
  2000年   4篇
  1999年   5篇
  1998年   4篇
  1997年   4篇
  1996年   4篇
  1995年   5篇
  1994年   6篇
  1993年   2篇
  1992年   5篇
  1991年   3篇
  1990年   1篇
  1989年   2篇
  1988年   4篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1981年   3篇
  1980年   3篇
  1979年   2篇
排序方式: 共有626条查询结果,搜索用时 15 毫秒
611.
Strenuous physical exercise of the limb muscles commonly results in damage, especially when that exercise is intense, prolonged and includes eccentric contractions. Many factors contribute to exercise-induced muscle injury and the mechanism is likely to differ with the type of exercise. Competitive sports players are highly susceptible to this type of injury. AM3 is an orally administered immunomodulator that reduces the synthesis of proinflammatory cytokines and normalizes defective cellular immune fractions. The ability of AM3 to prevent chronic muscle injury following strenuous exercise characterized by eccentric muscle contraction was evaluated in a double-blind and randomized pilot study. Fourteen professional male volleyball players from the First Division of the Spanish Volleyball League volunteered to take part. The participants were randomized to receive either placebo (n?=?7) or AM3 (n?=?7). The physical characteristics (mean±s) of the placebo group were as follows: age 25.7±2.1 years, body mass 87.2±4.1?kg, height 1.89±0.07?m, maximal oxygen uptake 65.3±4.2?ml?·?kg?1?·?min?1. Those of the AM3 group were as follows: age 26.1±1.9 years, body mass 85.8±6.1?kg, height 1.91±0.07?m, maximal oxygen uptake 64.6±4.5?ml?·?kg?1?·?min?1. All participants were evaluated for biochemical indices of muscle damage, including concentrations of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatine kinase (CK) and its MB fraction (CK-MB), myoglobin, lactate dehydrogenase, urea, creatinine and γ-glutamyltranspeptidase, both before and 30 days after treatment (over the peak of the competitive season). In the placebo group, competitive exercise (i.e. volleyball) was accompanied by significant increases in creatine kinase (494±51 to 560±53?IU?·?l?1, P?<?0.05) and myoglobin (76.8±2.9 to 83.9±3.1?μg?·?l?1, P?<?0.05); aspartate aminotransferase (30.8±3.0 to 31.1±2.9?IU?·?l?1) and lactate dehydrogenase (380±31 to 376±29?IU?·?l?1) were relatively unchanged after the 30 days maximum effort. AM3 not only inhibited these changes, it led to a decrease from baseline serum concentrations of creatine kinase (503±49 to 316±37?IU?·?l?1, P?<?0.05) and myoglobin (80.1±3.2 to 44.1±2.6?IU?·?l?1, P?<?0.05), as well as aspartate aminotransferase (31.1±3.3 to 26.1±2.7?IU?·?l?1, P?<?0.05) and lactate dehydrogenase (368±34 to 310±3?IU?·?l?1, P?<?0.05). The concentration of CK-MB was also significantly decreased from baseline with AM3 treatment (11.6±1.2 to 5.0±0.7?IU?·?l?1, P?<?0.05), but not with placebo (11.4±1.1 to 10.8±1.4?IU?·?l?1). In conclusion, the use of immunomodulators, such as AM3, by elite sportspersons during competition significantly reduces serum concentrations of proteins associated with muscle damage.  相似文献   
612.
Abstract

The purpose of this study was to determine whether aerobic plus resistance training (AT + RT) is more effective than aerobic training (AT) at reducing inflammatory markers and cardiovascular risk in obese adolescents. A total of 139 obese adolescents were enrolled, aged 15–19 years, body mass index (BMI) ≥ 95th percentile and participated in 1 year of interdisciplinary intervention. They were randomised into two groups: AT (n = 55), AT + RT (n = 61). Blood samples were collected to analyse glycaemia, insulin, the lipid profile, leptin and adiponectin concentrations. Insulin resistance was measured by homeostasis model assessment of insulin resistance index (HOMA-IR). The AT + RT group showed better results with regard to decreased body fat mass, low-density lipoprotein concentration (LDL-c) levels, subcutaneous and visceral fat and increased body lean mass. Indeed, a reduction of hyperleptinaemia and an increase in adiponectin concentrations, promoting an improvement in the leptin/adiponectin ratio, was observed. Important clinical parameters were improved in both types of exercise; however, AT + RT was more effective in improving the visceral adiposity, metabolic profile and inflammatory markers than AT alone, suggesting clinical applications for the control of intra-abdominal obesity and cardiovascular risk in the paediatric population.  相似文献   
613.
This article aims at studying the contradictions in scientific discourse on physical education for women in France from 1880 to 1922. In 1880 a law made gymnastics compulsory at school, and physical practices became a topic of public and scientific debate. 1922 is the date of the first medical congress on women's and children's physical education. Our study is based on a corpus of more than 200 scholarly texts about physical education or sport. They discuss women, exclusively conceived in their biological functions as procreators, thus physiologically qualifying the socially constructed properties of femininity. However, as soon as the first steps towards female physical practices appeared, contradictions came up. On the one hand, some doctors wanted to preserve reproductive organs from any violent exercises. On the other hand, other doctors wanted to reinforce female bodies through sport practices.  相似文献   
614.
This is the 20th in a series of articles exploring international trends in health science librarianship in the 21st century. The focus of the present issue is the Balkan region (Serbia and Slovenia). The next regular feature will look at Russia and the Ukraine. JM  相似文献   
615.
Educational Psychology Review - Over the last decades, extensive research has given considerable attention to teachers’ burnout. Owing to its negative personal, organizational, and social...  相似文献   
616.
Children growing up in poverty are at risk for various health problems. For low-income, Mexican-American children, these risks include obesity, diabetes, and accidental injuries, 3 conditions that can largely be prevented by healthy life-styles. Despite the potential for prevention through education leading to health-promoting behaviors, very little is known about the development of health knowledge in this population. The present study examined low-income, Mexican-American children's understanding of the relation between health behavior and health status in 3 areas: nutrition, hygiene, and safety. 79 children (41 boys, 38 girls) ages 4 to 8 years participated. Children's knowledge was assessed in a structured play situation conducted in a laboratory setting. Results revealed that children knew the least about the relation between food consumption and their health, and knew the most about beneficial and harmful practices in the areas of safety and hygiene. Age and gender differences were also significant, with girls and older children more likely to provide elaborate and complex rationales for their responses. Implications of the findings for understanding the role of cognitive development and experience in the development of health knowledge are considered.  相似文献   
617.
This study models graduation rates at 4-year broad access institutions (BAIs). We examine the student body, structural-demographic, and financial characteristics that best predict 6-year graduation rates across two time periods (2008–2009 and 2014–2015). A Bayesian model averaging approach is utilized to account for uncertainty in variable selection in modeling graduation rates. Evidence suggests that graduation rates can be predicted by religious affiliation, proportion of students enrolled full-time, socioeconomic status of the student body, enrollment size and institutional revenue and expenditures. Findings also demonstrate that relatively fewer variables predict institutional graduation rates for Latina/o and African American students at 4-year BAIs. We conclude with implications for policy and key recommendations for research focused on 4-year BAIs.  相似文献   
618.
This study investigates how, and to what extent, young readers (7–8 year-olds) use text information or their prior knowledge when answering comprehension questions about narrative texts. The children were asked to explain how they found out their responses by answering the following question: “how do you know this answer?” Their answers and justifications were analysed both qualitatively and quantitatively. The text proved to be the main source of information for these readers. However, sometimes the children seemed to ignore the text and over rely on their prior knowledge to answer the questions. The procedure of asking children to justify their answers was shown to be a good way of specifying more precisely some of their problems in text comprehension. It also seemed to encourage them to look back at the text and review their responses and, as such, it could be considered a useful tool to improve children’s reading comprehension.  相似文献   
619.
Although the importance of boundary spanning in blended and online learning is widely acknowledged, most educational research has ignored whether and how students learn from others outside their assigned group. One potential approach for understanding cross-boundary knowledge sharing is Social Network Analysis (SNA). In this article, we apply four network metrics to unpack how students developed intra- and inter-group learning links, using two exemplary blended case studies in Spain and the UK. Our results indicate that SNA based upon questionnaires can provide researchers some useful indicators for a more fine-grained analysis how students develop these inter- and intra-group learning links, and which cross-boundary links are particularly important for learning performance. The mixed findings between the two case-studies suggest the relevance of pre-existing conditions and learning design. SNA metrics can provide useful information for qualitative follow-up methods, and future interventions using learning analytics approaches.  相似文献   
620.
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