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   204篇
  免费   4篇
教育   93篇
科学研究   26篇
体育   54篇
文化理论   20篇
信息传播   15篇
  2022年   4篇
  2021年   5篇
  2020年   6篇
  2019年   13篇
  2018年   18篇
  2017年   7篇
  2016年   10篇
  2015年   5篇
  2014年   6篇
  2013年   34篇
  2012年   14篇
  2011年   12篇
  2010年   10篇
  2009年   7篇
  2008年   3篇
  2007年   7篇
  2006年   5篇
  2005年   2篇
  2004年   3篇
  2003年   1篇
  2002年   2篇
  2001年   4篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1994年   3篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1983年   3篇
  1975年   1篇
  1973年   1篇
  1898年   1篇
  1892年   1篇
排序方式: 共有208条查询结果,搜索用时 264 毫秒
131.
The knowledge of the morphological and mechanical properties of masonry walls is very important for the refurbishment of ancient buildings, particularly when the requirements of both structural safety and historical preservation must be fulfilled. The masonry is not of homogenous material: its mechanical properties depend on stones, mortar, and texture which are very variable due to their dependence on the historical periods and the geographical area of the erection. For this reason, a deep knowledge of masonries built in different sites and historical periods is essential in order to evaluate both the capacities of bearing vertical load and the seismic vulnerability of the masonry structure. Three fundamental typologies of tuff masonry have been defined: they are the characteristics of different historical periods from the XVI to the XX century. The models are in full-scale in order to reproduce the three defined chronotypes. Original tuff stones quarried in the corresponding historical period, mortars similar to the original ones, reproduced according to ancient documents and original constructive techniques have been used for the construction of the specimens. Compression tests performed in displacement control have been carried out on the masonry models in order to determine the maximum resistance of the material and the corresponding strain, the ultimate strain and corresponding residual strength. In this paper, the procedure used for making the specimens and for experimentally evaluating the mechanical properties of post-medieval Neapolitan yellow tuff masonry are illustrated and the obtained results, even in terms of plastic capacity of these kinds of masonry, are reported.  相似文献   
132.
ABSTRACT

The aim of this study was to propose a group of parameters able to quantify not only arm coordination but also inter limb coordination. These include the well know index of coordination with the relative duration of the stroke phases and two new parameters: the Index of synchronization (Ids) between arms and legs actions; and the Index of inter limb coordination (IdIC) calculated as the relative foot position during successive arm stroke phases. These parameters were compared between experts and amateur swimmers in a maximal front crawl sprint. The influence of arm stroke in leg kick parameters was also assessed, comparing the full stroke condition with a condition without arms actions. Sixty-five per cent of expert swimmers used synchronized limb actions while 95% of amateur swimmers used non-synchronized limb motions. These synchronized expert swimmers also converged towards a specific coordination pattern between foot position and arm stroke phases. In the condition without arms, both groups changed kick rate and amplitude. The present study reveals the interdependency of arms and legs actions and the importance of coordination and synchronization between limbs. Therefore, the proposed group of overall indexes of coordination provides a more complete marker for the analysis of swimming technique.  相似文献   
133.
Abstract This study investigated effects of manipulating the number of action possibilities in a futsal passing task to understand the representativeness of practice tasks designs. Eight male senior futsal players performed a passing task in which uncertainty on passing direction for the player in possession of the ball was increased in four conditions and compared with passing data from a competitive match. Performance during a passing task and competitive futsal performance was compared using ball speed and passing accuracy data. Ball speed data were analysed by approximate entropy (ApEn) to capture their regularity in each of the four conditions and during competitive performance. Significantly high levels of regularity were observed in predetermined passes in comparison with emergent passes (i.e., passes with high number of possibilities for action). Similar results for ball speed regularity were observed between practice tasks with a high number of possibilities for action (i.e., emergent passes) and competitive performance. Similar results were observed for passing accuracy in practice tasks with a high number of possibilities for action compared to competitive performance. Increases in the number of action possibilities during practice improved action fidelity of tasks in relation to competitive performance.  相似文献   
134.
Background:Physical activity,sleep,and sedentary behaviors compose 24-h movement behaviors and have been independently associated with depressive symptoms.However,it is not clear whether it is the movement behavior itself or other contextual factors that are related to depressive symptoms.The objective of the present study was to examine the associations between self-reported and accelerometer-measured movement behaviors and depressive symptoms in adolescents.Methods:Cross-sectional data from 610 adolescents(14-18 years old)were used.Adolescents answered questions from the Center for Epidemiological Studies Depression scale and reported time spent watching videos,playing videogames,using social media,time spent in various physical activities,and daytime sleepiness.Wrist-worn accelerometers were used to measure sleep duration,sleep efficiency,sedentary time,and physical activity.Mixed-effects logistic regressions were used.Results:Almost half of the adolescents(48%)were classified as being at high risk for depression(score≥20).No significant associations were found between depressive symptoms and accelerometer-measured movement behaviors,self-reported non-sport physical activity,watching videos,and playing videogames.However,higher levels of self-reported total physical activity(odd ratio(OR)=0.92,95%confidence interval(95%CI):0.86-0.98)and volume of sports(OR=0.88,95%CI:0.79-0.97),in minutes,were associated with a lower risk of depression,while using social media for either 2.0-3.9 h/day(OR=1.77,95%CI:1.58-2.70)or>3.9 h/day(OR=1.67,95%CI:1.10-2.54),as well as higher levels of daytime sleepiness(OR=1.17,95%CI:1.12-1.22),were associated with a higher risk of depression.Conclusion:What adolescents do when they are active or sedentary may be more important than the time spent in the movement behaviors because it relates to depressive symptoms.Targeting daytime sleepiness,promoting sports,and limiting social media use may benefit adolescents.  相似文献   
135.
136.
We conducted an exploratory study evaluating the potential impact of intergenerational programming (IG) on children's socio-emotional development, behavior, school performance, and attitudes and behavior toward older adults. Children currently in kindergarten through second grade (age range: 6–8 years old) who previously attended one of two preschools of comparably high quality and serving families of similar demographic profiles were compared 1–3 years after graduating from their respective programs. One program offered intergenerational (IG) programming while the other was a traditional single-generation program (SG). Face-to-face interviews were conducted with the child and one of his/her parents in their home. In addition, a mail survey was sent to the child's school teacher. The study explored whether children exposed to IG had differential outcomes on specific measures as compared to children who attended the SG program. Results showed that children from the IG program had higher levels of social acceptance, a greater willingness to help and greater empathy for older people, slightly more positive attitudes, and better able to self-regulate their behavior than children from the SG program. Although limited by the lack of a pre–post experimental design, these results provide initial evidence that an IG program can offer additional benefits to children's development whose impact can last into the their early school age years.  相似文献   
137.
The authors analyze the efficacy of a cooperative method associated with self-regulated strategy development (SRSD) for argumentative writing compared with a SRSD single approach. Seven teachers and 230 ninth-grade students from three middle schools participated in the present study in which teachers were part of a practice-based professional development program. Schools were assigned either to the experimental group or to the comparison group. Over a three-month period, all students were taught SRSD strategies. After this period, students from the experimental group participated in a cooperative setting, whereas the comparison group followed the SRSD only. The results indicated that students in the experimental group made statistically significant greater gains in structural argumentative elements and in the quality of writing texts immediately after the intervention and one month later. Thus, the study provides evidence for the benefits of adding a cooperative setting to SRSD in implementing argumentative writing skills.  相似文献   
138.
The aim of this study was to compare the effects of 11 weeks of low-volume resistance training (LVRT) and high-volume resistance training (HVRT) on muscle strength, muscle thickness (MT), and postprandial lipaemia (PPL) in postmenopausal women. Thirty-six healthy and untrained postmenopausal women (age, 58.9 ± 5.8 years; 68.6 ± 10.3 kg; and BMI, 26.9 ± 4.8 kg · m?2) participated in resistance training 3× per week for 11 weeks (HVRT = 12; LVRT = 13; and control group = 11). Biochemical variables, both pretraining and post-training, were evaluated 16 h after the administration of an oral fat tolerance test (OFTT) and metabolic variable during [energy expenditure (EE)] and after training session [excess postexercise oxygen consumption (EPOC)]. Muscle strength (1 RM) and MT were also calculated, and no significant differences were observed between the groups for PPL (mmol · L?1 per 5 h) as measured by glucose, high-density lipoprotein, low-density lipoprotein, and total cholesterol. EE total (EE + EPOC; 6.12 ± 1.21 MJ vs. 2.26 ± 0.85 MJ), resting fat oxidation (5.52 ± 1.69 g · h?1 vs. 4.11 ± 1.12 g · h?1); MT (vastus medialis, 21.4 ± 1.8 mm vs. 18.4 ± 1.2 mm and vastus lateralis 22.3 ± 1.2 mm vs. 20.8 ± 1.3 mm); triacylglycerol (TAG) 0, 1, 2, 4; and 5 h after OFTT, TAG area under the curve (AUC) (5.79 ± 0.42 vs. 7.78 ± 0.68), and incremental AUC (?46.21 ± 14.42% vs. 7.78 ± 4.68%) were all significantly different post-training for HVRT versus LVRT, respectively (P < 0.05). The results of this investigation suggest that HVRT reduces PPL in postmenopausal women.  相似文献   
139.
140.
The purpose of this column is to keep religious educators abreast of the relevant significant research in the general field of psychology. Its implications for methods and materials in religious education are clear. Religious educators may well take advantage of every new finding in scientific research.

Each abstract or group is preceded by an evaluation and interpretative comment, which aims to guide the reader in understanding the research reported.

All of these abstracts are from PSYCHOLOGICAL ABSTRACTS, and used by permission of that periodical. The abstract number is Volume 32, Number 2, April 1958.  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