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   1759篇
  免费   32篇
  国内免费   3篇
教育   1382篇
科学研究   36篇
各国文化   44篇
体育   97篇
综合类   2篇
文化理论   8篇
信息传播   225篇
  2023年   10篇
  2022年   12篇
  2021年   28篇
  2020年   60篇
  2019年   61篇
  2018年   91篇
  2017年   91篇
  2016年   82篇
  2015年   36篇
  2014年   78篇
  2013年   363篇
  2012年   49篇
  2011年   55篇
  2010年   47篇
  2009年   50篇
  2008年   60篇
  2007年   45篇
  2006年   43篇
  2005年   37篇
  2004年   34篇
  2003年   36篇
  2002年   48篇
  2001年   40篇
  2000年   30篇
  1999年   15篇
  1998年   13篇
  1997年   15篇
  1996年   12篇
  1995年   15篇
  1994年   15篇
  1993年   13篇
  1992年   16篇
  1991年   15篇
  1990年   11篇
  1989年   13篇
  1988年   14篇
  1987年   19篇
  1986年   6篇
  1985年   10篇
  1984年   8篇
  1983年   8篇
  1982年   7篇
  1981年   8篇
  1980年   7篇
  1979年   14篇
  1978年   7篇
  1977年   12篇
  1976年   9篇
  1975年   7篇
  1967年   3篇
排序方式: 共有1794条查询结果,搜索用时 15 毫秒
51.
BackgroundOne-hour postprandial hyperglycemia is associated with increased risk of type 2 diabetes and cardiovascular disease. Physical activity (PA) has short-term beneficial effects on post-meal glucose response. This study compared the oral glucose tolerance test results of 3 groups of people with habitually different levels of PA.MethodsThirty-one adults without diabetes (age 25.9 ± 6.6 years; body mass index 23.8 ± 3.8 kg/m2; mean ± SD) were recruited and divided into 3 groups based on self-reported PA volume and intensity: low activity < 30 min/day of moderate-intensity activity (n = 11), moderately active ≥ 30 min/day of moderate-intensity PA (n = 10), and very active ≥ 60 min/day of PA at high intensity (n = 10). Participants completed an oral glucose tolerance test (50 g glucose) with capillary blood samples obtained at baseline, 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min post-ingestion.ResultsThere were no significant differences between groups for age or body fat percentage or glycated hemoglobin (p > 0.05). The groups were significantly different in terms of baseline glucose level (p = 0.003) and, marginally, for gender (p = 0.053) and BMI (p = 0.050). There was a statistically significant effect of PA on the 1-h postprandial glucose results (p = 0.029), with differences between very active and low activity groups (p = 0.008) but not between the moderately active and low activity groups (p = 0.360), even when baseline glucose level and gender differences were accounted for. For incremental area under the curve there was no significant effect of activity group once gender and body fat percentage had been accounted for (p = 0.401). Those in the low activity group took 15 min longer to reach peak glucose level than those in the very active group (p = 0.012).ConclusionThe results suggest that high levels of PA have a beneficial effect on postprandial blood glucose profiles when compared to low and moderate levels of activity.  相似文献   
52.
Physical activity (PA) is a key element in Cystic Fibrosis (CF) treatment strategies, yet little is known as to whether activity compensation occurs. This study examined whether PA and/or sedentary time on one day were temporally associated with time spent in these intensities the following day in youth with CF. Time spent sedentary and in different PA intensities were objectively-measured for seven consecutive days in 50 youth (22 boys; 12.0 ± 2.7 years); 25 with mild-to-moderate CF and 25 age- and sex-matched controls. Multilevel analyses (day and child) were conducted using generalised linear latent and mixed models. On any given day, every additional 10 minutes spent in sedentary time or moderate-to-vigorous physical activity (MVPA) were associated with 1.9 (95%CI: ?3.6 to ?1.2) and 12.4 (95%CI: ?22.1 to ?2.9) minutes less sedentary time the following day, respectively. These temporal associations were also observed when split by group (3.1 vs. 1.9 minutes for healthy and CF, respectively). These findings indicate that youth do not compensate their PA, irrespective of disease status, between days, but may compensate their sedentary time between days. Experimental studies are warranted to fully elucidate whether compensatory responses to PA and sedentary time occur, which is fundamental for informing PA promotion strategies.  相似文献   
53.
54.
This paper, which was part of the International Association of Athletics Federations (IAAF) 2007 Nutritional Consensus Conference, briefly reviews the components of the female athlete triad (Triad): energy availability, menstrual status, and bone health. Each component of the Triad spans a continuum from health to disease, and female athletes can have symptoms related to each component of the Triad to different degrees. Low energy availability is the primary factor that impairs menstrual dysfunction and bone health in the Triad. We discuss nutritional issues associated with the Triad, focusing on intakes of macronutrients needed for good health, and stress fractures, the most common injury associated with the Triad. Finally, we briefly discuss screening and treatment for the Triad and the occurrence of the Triad in men.  相似文献   
55.
This study assessed changes in selected physiological and kinematic variables over 6 weeks of treadmill skating in an effort to understand the process of habituation to this novel training modality. Seven male, Atom-A hockey players who were injury-free and had no previous treadmill skating experience participated in the study. Players performed four 1-min skating bouts at progressively increasing speeds, each week, for 6 weeks. One speed (10.5 km/h) was repeated weekly to allow for assessment of the habituation process. Our criteria for habituation were: a decrease in stride rate, heart rate and rating of perceived exertion, and an increase in stride length, trunk angle and vertical movement of the centre of mass, leading to a plateau, over the course of the 6-week study. Significant decreases were seen in stride rate, heart rate and ratings of perceived exertion, and significant increases were found in stride length. Some of these changes were evident after only one week of training and all were present by week 4. After 6 weeks (24 min) of exposure to treadmill skating, all participants displayed a visibly more efficient skating style.  相似文献   
56.
This article compiles original data relating to artists’ place of birth and work migration patterns using various art history dictionaries. The broad historic pattern, from the 13th to the 20th century, of the birth locations of prominent artists is examined, followed by a detailed study of the work migration patterns of prominent artists in two important situations, namely Renaissance Italy and France in part of the 19th century. The evidence indicates a marked clustering of activity of prominent artists, both arising from birth location and migration patterns. Some possible explanations for the observed patterns are briefly outlined.
John O’HaganEmail:
  相似文献   
57.
This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 +/- 24 beats per minute [bpm]) compared to team (118 +/- 24 bpm) or individual (114 +/- 18) activities. Similar results occurred for the percentage of activity time spent within a target heart rate zone (fitness 81.7 +/- 15.9%, individual 68.4 +/- 30.5%, and team 60.6 +/- 30.5%). Boys attained higher heart rates during team activities, while female students had higher rates during individual activities indicating male and female adolescents respond differently to activity types. The highest mean heart rates were observed during fitness activities.  相似文献   
58.
Workbook reading achievement of five second-grade girls was assessed under two teacher-contact contingencies. Under one contingency, teacher contacts were made during on-task behavior. Under the other contingency, differential reinforcement of an incompatible behavior (DRI) was in effect, with teacher contacts contingent on students' hand-raising behavior. Both reading achievement and time on task were greater under the on-task contingency than under DRI for hand raising.  相似文献   
59.
60.
Twenty-one dual-earner families whose preschool-aged children entered day care before 6 months of age and 19 dual-earner families whose preschool-aged children entered day care during the second year of life filled out questionnaires on the nature of their children's caregiving environment; their perceptions of the effects of day care on parent-child interaction and children's development; their overall job satisfaction; social support networks; and personal well-being, marital stress, and companionship. Mothers and fathers reported high levels of satisfaction with the caregiving environment and the effects of day care. Parental perceptions of the effects of day care on parent-child interaction and children's development did not differ as a function of time of entry into day care. Parental perceptions of selected parent-child variables were associated with job satisfaction, social support, and the marital measures. Parental perceptions of parent-child interaction were related to their perceptions of the effects of day care on children's social and cognitive skills. Mothers and fathers differed in these perceptions. There was some support for a conceptual link between marital variables and children's functioning in day care.  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