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   376篇
  免费   4篇
教育   278篇
科学研究   13篇
体育   45篇
文化理论   11篇
信息传播   33篇
  2023年   2篇
  2022年   5篇
  2021年   7篇
  2020年   11篇
  2019年   14篇
  2018年   27篇
  2017年   17篇
  2016年   20篇
  2015年   7篇
  2014年   24篇
  2013年   82篇
  2012年   8篇
  2011年   12篇
  2010年   14篇
  2009年   14篇
  2008年   10篇
  2007年   11篇
  2006年   4篇
  2005年   6篇
  2004年   8篇
  2003年   3篇
  2002年   3篇
  2001年   4篇
  2000年   5篇
  1999年   4篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1995年   3篇
  1994年   6篇
  1990年   4篇
  1987年   4篇
  1986年   2篇
  1984年   2篇
  1981年   2篇
  1979年   2篇
  1978年   2篇
  1977年   1篇
  1976年   3篇
  1975年   3篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
  1969年   2篇
  1967年   1篇
  1928年   1篇
  1926年   1篇
  1925年   1篇
  1924年   1篇
  1921年   1篇
排序方式: 共有380条查询结果,搜索用时 0 毫秒
151.
The purpose of this study was to provide a more detailed analysis of performance in cross-country skiing by combining findings from a differential global positioning system (dGPS), metabolic gas measurements, speed in different sections of a ski-course and treadmill threshold data. Ten male skiers participated in a freestyle skiing field test (5.6 km), which was performed with dGPS and metabolic gas measurements. A treadmill running threshold test was also performed and the following parameters were derived: anaerobic threshold, threshold of decompensated metabolic acidosis, respiratory exchange ratio = 1, onset of blood lactate accumulation and peak oxygen uptake (VO2peak). The combined dGPS and metabolic gas measurements made detailed analysis of performance possible. The strongest correlations between the treadmill data and final skiing field test time were for VO2peak (l x min(-1)), respiratory exchange ratio = 1 (l x min(-1)) and onset of blood lactate accumulation (l x min(-1)) (r = -0.644 to - 0.750). However, all treadmill test data displayed stronger associations with speed in different stretches of the course than with final time, which stresses the value of a detailed analysis of performance in cross-country skiing. Mean oxygen uptake (VO2) in a particular stretch in relation to speed in the same stretch displayed its strongest correlation coefficients in most stretches when VO2 was presented in units litres per minute, rather than when VO2 was normalized to body mass (ml x kg(-1) x min(-1) and ml x min(-1) x kg(-2/3)). This suggests that heavy cross-country skiers have an advantage over their lighter counterparts. In one steep uphill stretch, however, VO2 (ml x min(-1) x kg(-2/3)) displayed the strongest association with speed, suggesting that in steep uphill sections light skiers could have an advantage over heavier skiers.  相似文献   
152.
Funori is a polysaccharide-based adhesive extracted from seaweeds and is generally used in the conservation of easel paintings for the consolidation of matte paint. It is appreciated since it does not change the optical properties of the consolidated materials and its mechanical properties do not change with ageing. Because of these characteristics, this research focused on the evaluation of Funori as a suitable material for the consolidation of powdering paint layers in wall paintings. Tests were carried out where Funori was applied onto painted plaster replicas, which were then artificially aged and investigated in order to evaluate the material's behaviour according to the specific properties and conditions of wall paintings. The effectiveness of the consolidation was evaluated from the point of view of adhesive power, as well as the interactions of Funori with some physical properties of the consolidated painting, such as colour and water vapour permeability and, therefore, its resistance to accelerated ageing and biological colonization. In addition, the behaviour of Funori applied on plasters contaminated with soluble salts, a frequent condition in wall paintings, was also evaluated.  相似文献   
153.
The authors examined psychological distress and relational patterns in college men and women. Peer, mentor, and community relationships; year in school; and family experiences were hypothesized to predict psychological distress, although predictive patterns were expected to differ in women and men. Overall, results supported the hypotheses. Findings are interpreted from the perspective of the relational‐cultural model. Counseling implications focus on interventions congruent with the specific relational needs of women and men.  相似文献   
154.
It was proposed that previously observed grade-related changes in children's social comparison behavior could be explained by the changing goals and meanings children assign to this behavior. Specifically, it was suggested that, as children progress through the school system, they become increasingly aware of the negative and positive aspects of social comparison and adjust their behavior in response to this awareness, as well as to increasingly salient self-evaluation goals. To examine these propositions, 106 elementary school children were observed in their classrooms and interviewed once a year for 3 years. Consistent with previous research, overt forms of social comparison were most frequent among younger children, whereas subtle forms of social comparison were most frequent among older children. Furthermore, with increasing grade children were likely to view overt forms of social comparison negatively and subtle forms as useful in meeting self-evaluation goals. Additional analyses revealed little association between perceptions of social comparison and actual social comparison behavior, except that perceiving subtle social comparison as useful for self-evaluative goals predicted engagement in such behavior 2 years later.  相似文献   
155.
This study profiles gender differences in instrumental performance self-efficacy perceptions of high school students (N?=?87) over the course of a three-day orchestra festival in which students competed against one another for rank-based seating and then rehearsed and performed as a group. Reported self-beliefs rose significantly for the sample over the course of the festival. Self-efficacy beliefs of females were significantly lower than those of males before the seating audition and first rehearsal, but were no longer different by the midpoint of the festival. Survey free-response data were coded according to Bandura's (1997 Bandura, A. 1997. Self-efficacy: The Exercise of Control. New York: W. H. Freeman. [Google Scholar]) four sources of self-efficacy. A 52% drop in the frequency of student comments regarding competitive comparison appeared at the same point in which female self-efficacy beliefs were no longer different from those of males. Results support past research to suggest that males and females may respond differently to rank-based competition versus social support.  相似文献   
156.
Inquiry-based labs have been shown to greatly increase student participation and learning within the biological sciences. One challenge is to develop effective lab exercises within the constraints of large introductory labs. We have designed a lab for first-year biology majors to address two primary goals: to provide effective learning of the unique aspects of the plant life cycle and to gain a practical knowledge of experimental design. An additional goal was to engage students regardless of their biology background. In our experience, plant biology, and the plant life cycle in particular, present a pedagogical challenge because of negative student attitudes and lack of experience with this topic. This lab uses the fern Ceratopteris richardii (C-Fern), a model system for teaching and research that is particularly useful for illustrating alternation of generations. This lab does not simply present the stages of the life cycle; it also uses knowledge of alternation of generations as a starting point for characterizing the her1 mutation that affects gametophyte sexual development. Students develop hypotheses, arrive at an appropriate experimental design, and carry out a guided inquiry on the mechanism underlying the her1 mutation. Quantitative assessment of student learning and attitudes demonstrate that this lab achieves the desired goals.  相似文献   
157.
The purpose of this study was to validate a wireless network of accelerometers and compare it to a hip-mounted accelerometer for predicting energy expenditure in a semi-structured environment. Adults (n = 25) aged 18–30 engaged in 14 sedentary, ambulatory, exercise, and lifestyle activities over a 60-min protocol while wearing a portable metabolic analyser, hip-mounted accelerometer, and wireless network of three accelerometers worn on the right wrist, thigh, and ankle. Participants chose the order and duration of activities. Artificial neural networks were created separately for the wireless network and hip accelerometer for energy expenditure prediction. The wireless network had higher correlations (r = 0.79 vs. r = 0.72, P < 0.01) but similar root mean square error (2.16 vs. 2.09 METs, P > 0.05) to the hip accelerometer. Measured (from metabolic analyser) and predicted energy expenditure from the hip accelerometer were significantly different for the 3 of the 14 activities (lying down, sweeping, and cycle fast); conversely, measured and predicted energy expenditure from the wireless network were not significantly different for any activity. In conclusion, the wireless network yielded a small improvement over the hip accelerometer, providing evidence that the wireless network can produce accurate estimates of energy expenditure in adults participating in a range of activities.  相似文献   
158.
The present article analyzes the development of the ethnic gap—with respect to the attainment of vocational degrees—over the immigration cohorts 1960–2001 by examining how social integration indicators and general secondary school education may help to explain the trend. It was found that the gap between natives and migrants increased. Above all, the large increase in the gap over cohorts between Germans and Turks is alarming. In contrast to that the gap and its increase between the group of immigrants from Central-/Eastern-/Southeastern European countries as well as from other former recruitment countries and German natives is comparably small and can to a large extent be explained by a growing gap regarding the level of general secondary education among the newer immigration cohorts and native Germans due to educational expansion and to a growing impact of the secondary school education for the achievement of vocational education. The effect of social integration plays a smaller role compared to general secondary school education and it even decreases over immigration cohorts.  相似文献   
159.
160.
This study investigated whether German learners of English as a foreign language (EFL) acquire additional recoding strategies that they do not need for recoding in the consistent German orthography. Based on the psycholinguistic grain size theory (Ziegler & Goswami, 2005) we expected students with little experience in EFL to use the same small-grain recoding strategy as in German, while more advanced students were expected to switch flexibly between small and large grain size recoding strategies when reading English nonwords. German students in Grades 5, 7, and 9, as well as university students were presented with an experimental nonword reading paradigm introduced by Goswami, Ziegler, Dalton, and Schneider (2003) which assesses the effects of language (nonwords derived from German vs. English), orthographic neighborhood, item length and presentation format (blocked vs. mixed) on reading latencies and accuracies. The data were analyzed using hierarchical linear models. The youngest age group did not use larger units to read English nonwords, but mostly applied simple grapheme-phoneme translation, as they would in their first language. University students were able to switch flexibly between large- and small size recoding strategies.  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