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   3450篇
  免费   55篇
教育   2640篇
科学研究   167篇
各国文化   36篇
体育   303篇
综合类   2篇
文化理论   39篇
信息传播   318篇
  2023年   22篇
  2022年   52篇
  2021年   63篇
  2020年   108篇
  2019年   180篇
  2018年   217篇
  2017年   215篇
  2016年   194篇
  2015年   149篇
  2014年   130篇
  2013年   775篇
  2012年   116篇
  2011年   111篇
  2010年   67篇
  2009年   73篇
  2008年   88篇
  2007年   71篇
  2006年   62篇
  2005年   62篇
  2004年   52篇
  2003年   52篇
  2002年   50篇
  2001年   38篇
  2000年   22篇
  1999年   25篇
  1998年   23篇
  1997年   19篇
  1996年   50篇
  1995年   29篇
  1994年   35篇
  1993年   37篇
  1992年   26篇
  1991年   27篇
  1990年   28篇
  1989年   22篇
  1988年   16篇
  1987年   11篇
  1986年   13篇
  1985年   14篇
  1984年   18篇
  1983年   14篇
  1982年   12篇
  1981年   11篇
  1980年   14篇
  1979年   14篇
  1978年   9篇
  1977年   16篇
  1976年   9篇
  1970年   5篇
  1967年   5篇
排序方式: 共有3505条查询结果,搜索用时 15 毫秒
241.
242.
243.
The authors analyzed data from the School Health Policies and Programs Study 2000 to assess the associations between the presence of a district physical education coordinator and district-level physical education policies and practices recommended by federal government agencies and national organizations. The authors also examined the relationship between teacher qualifications and staff development related to physical education and self-reported implementation of recommended teachingpractices. District-level data were collected by self-administered mail questionnaires from a nationally representative sample of school districts. Classroom-level data were collected by computer-assisted personal interviews with teachers of randomly selected classes in elementary schools and randomly selected required physical education courses in middle/junior high and senior high schools. Nearly two thirds (62.2%) of districts had a physical education coordinator, and those were generally more likely than other districts to report having policies and practices that corresponded with national recommendations for high-quality physical education programs. More than two thirds of teachers (66.9%) met the criteria for teacher qualifications based on their education and certification. These teachers were more likely than others to report use of certain recommended physical education teaching practices. Teachers who participated in staff development also were more likely to use recommended teaching practices in their classrooms. Using a district physical education coordinator and teachers with appropriate qualifications as well as offering staff development opportunities on physical education may enhance school physical education programs.  相似文献   
244.
The Competitive State Anxiety Inventory-2 (CSAI-2) is one of the most frequently used instruments when assessing competitive state anxiety in sport psychology research. However, doubts have been expressed about the factorial validity of both the English and the Greek versions of the scale. Hence, a revised version of the inventory (CSAI-2R) has recently been suggested to be more psychometrically sound (Cox et al., 2003). In the present study, the aim was to evaluate the psychometric properties of the Swedish version of the CSAI-2 using confirmatory factor analyses. A total of 969 athletes (571 men and 398 women) competing in 26 different sports completed the Swedish version of the CSAI-2. Three different factor structures were evaluated: the original three-factor model (with cognitive anxiety, somatic anxiety and self-confidence), a two-factor model in which self-confidence was excluded, and a three-factor model containing 17 items (CSAI-2R). The results revealed that only the 17-item model displayed an acceptable fit to the data. Although some doubts remain about the amount of variance that can be attributed to error variance in the subscales, the results suggest that it is better to use the CSAI-2R rather than the original CSAI-2.  相似文献   
245.
246.
Two experimental procedures for positively modifying the attitudes of regular classroom children towards the handicapped were conducted. In both studies, curriculum and/or experiences with the handicapped were introduced to randomly selected groups of regular class elementary children. The curriculum consisted of literature, filmstrips, and lectures about handicapped children, while the experiences consisted of controlled integrational activities. The results indicated that the procedures were partially successful in modifying the attitudes of regular class children towards the handicapped. It was concluded that techniques must be developed systematically for achieving more positive attitudes in regular class children if “mainstreaming” is to become an effective educational concept.  相似文献   
247.
Electrosprays are a powerful technique to generate charged micro/nanodroplets. In the last century, the technique has been extensively studied, developed, and recognized with a shared Nobel price in Chemistry in 2002 for its wide spread application in mass spectrometry. However, nowadays techniques based on microfluidic devices are competing to be the next generation in atomization techniques. Therefore, an interesting development would be to integrate the electrospray technique into a microfluidic liquid-liquid device. Several works in the literature have attempted to build a microfluidic electrospray with disputable results. The main problem for its integration is the lack of knowledge of the working parameters of the liquid-liquid electrospray. The “submerged electrosprays” share similar properties as their counterparts in air. However, in the microfluidic generation of micro/nanodroplets, the liquid-liquid interfaces are normally stabilized with surface active agents, which might have critical effects on the electrospray behavior. In this work, we review the main properties of the submerged electrosprays in liquid baths with no surfactant, and we methodically study the behavior of the system for increasing surfactant concentrations. The different regimes found are then analyzed and compared with both classical and more recent experimental, theoretical and numerical studies. A very rich phenomenology is found when the surface tension is allowed to vary in the system. More concretely, the lower states of electrification achieved with the reduced surface tension regimes might be of interest in biological or biomedical applications in which excessive electrification can be hazardous for the encapsulated entities.  相似文献   
248.
Abstract High physical fitness in childhood and adolescence is positively associated with favourable health-related outcomes. Our aim was to examine the relationship between relatives' (father, mother, brother, sister, and best friend) physical activity engagement and encouragement on adolescents' physical fitness. Adolescents were part of the HELENA study, a multi-centre study conducted in 10 cities from nine European countries in 2006-2008. Participants were 3288 adolescents (48% boys, 52% girls) aged 12.5-17.5 years with valid data on at least one of the three fitness variables studied: muscular strength (standing long jump), speed/agility (4×10 m shuttle run), and cardiorespiratory fitness (20 m shuttle run). The adolescents reported their relatives' physical activity engagement and encouragement. Analysis of covariance showed that relatives' physical activity engagement (father, mother, brother, and best friend) was positively related to cardiorespiratory fitness (P?相似文献   
249.
This study examined the influence of the regression model and initial intensity of an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and the endurance performance. Sixteen non-competitive, recreational female runners performed a discontinuous incremental treadmill test. The initial speed was set at 7 km · h?1, and increased every 3 min by 1 km · h?1 with a 30-s rest between the stages used for earlobe capillary blood sample collection. Lactate-speed data were fitted by an exponential-plus-constant and a third-order polynomial equation. The lactate threshold was determined for both regression equations, using all the coordinates, excluding the first and excluding the first and second initial points. Mean speed of a 10-km road race was the performance index (3.04 ± 0.22 m · s?1). The exponentially-derived lactate threshold had a higher correlation (0.98 ≤ r ≤ 0.99) and smaller standard error of estimate (SEE) (0.04 ≤ SEE ≤ 0.05 m · s?1) with performance than the polynomially-derived equivalent (0.83 ≤ r ≤ 0.89; 0.10 ≤ SEE ≤ 0.13 m · s?1). The exponential lactate threshold was greater than the polynomial equivalent (P < 0.05). The results suggest that the exponential lactate threshold is a valid performance index that is independent of the initial intensity of the incremental test and better than the polynomial equivalent.  相似文献   
250.
As a mixture of new technologies, processes and services oriented to the citizen, e-government has become one of the most important keywords for the public sector reform with proponents claiming that it guarantees transparency, accountability and better communication between local and national administrations and their public. Few if any studies have investigated the factors that might contribute to the establishment of trusting relationship between city councils and citizens. This paper examines the relative importance and significance of three types of information communication technologies (ICTs) towards the use of e-government and the development of civic engagement. We conduct an empirical investigation of 179 Spanish official town websites (web sites in the municipalities). The research findings suggest that implementing ICT not only involves a step towards an increase in the use of e-government services by people, but also provides numerous opportunities for their civic engagement. The main conclusion of this study is that although ICT can leverage the adoption of e-government, it cannot create alone engagement with traditional activities of the local government. What is missing from this relationship is a mediating variable (adoption of e-government by government officers), which in turn can greatly help to better understand how ICT impacts relationships between governments and their citizens.  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