全文获取类型
收费全文 | 2432篇 |
免费 | 55篇 |
国内免费 | 4篇 |
专业分类
教育 | 1809篇 |
科学研究 | 119篇 |
各国文化 | 60篇 |
体育 | 246篇 |
综合类 | 1篇 |
文化理论 | 28篇 |
信息传播 | 228篇 |
出版年
2022年 | 16篇 |
2021年 | 21篇 |
2020年 | 43篇 |
2019年 | 62篇 |
2018年 | 96篇 |
2017年 | 103篇 |
2016年 | 93篇 |
2015年 | 61篇 |
2014年 | 87篇 |
2013年 | 531篇 |
2012年 | 78篇 |
2011年 | 74篇 |
2010年 | 59篇 |
2009年 | 69篇 |
2008年 | 86篇 |
2007年 | 63篇 |
2006年 | 69篇 |
2005年 | 61篇 |
2004年 | 46篇 |
2003年 | 62篇 |
2002年 | 64篇 |
2001年 | 43篇 |
2000年 | 31篇 |
1999年 | 35篇 |
1998年 | 22篇 |
1997年 | 36篇 |
1996年 | 35篇 |
1995年 | 35篇 |
1994年 | 19篇 |
1993年 | 21篇 |
1992年 | 22篇 |
1991年 | 31篇 |
1990年 | 20篇 |
1989年 | 25篇 |
1988年 | 16篇 |
1987年 | 13篇 |
1986年 | 24篇 |
1985年 | 16篇 |
1984年 | 15篇 |
1983年 | 19篇 |
1982年 | 25篇 |
1981年 | 18篇 |
1980年 | 8篇 |
1979年 | 23篇 |
1978年 | 9篇 |
1977年 | 14篇 |
1976年 | 12篇 |
1974年 | 7篇 |
1972年 | 6篇 |
1967年 | 5篇 |
排序方式: 共有2491条查询结果,搜索用时 0 毫秒
31.
Stephen O. Ajayi 《Africa Education Review》2019,16(2):1-15
Four theoretical frameworks were used to explore causations of turnover amongst high school teachers in Nigeria: (1) teachers’ personal health, (2) work–family life, (3) job satisfaction, and (4) actual turnover intention. Quantitative data were obtained from 925 public high school teachers in Ogun State, South-Western Nigeria. Cronbach's Alpha reliability procedure, regression modelling and t-test were used to analyse a total of 96 causations of turnover. Ad hoc analysis returned an Alpha value of 0.78. However, this improved to 0.93 when the causation factors were reduced to 64 – those with highest item-rest and itemtotal correlations. The findings showed that job (dis)satisfaction, personal health and work– family life conflict are prominent amongst the issues that trigger the intention of Nigerian high school teachers to quit their jobs voluntarily. Insights from the findings will help funding administrators in prioritising strategic decisions around mitigating turnover. 相似文献
32.
The standard model (SM) of particle physics, comprised of the unified electroweak and quantum chromodynamic theories, accurately explains almost all experimental results related to the micro-world, and has made a number of predictions for previously unseen particles, most notably the Higgs scalar boson, that were subsequently discovered. As a result, the SM is currently universally accepted as the theory of the fundamental particles and their interactions. However, in spite of its numerous successes, the SM has a number of apparent shortcomings, including: many free parameters that must be supplied by experimental measurements; no mechanism to produce the dominance of matter over antimatter in the universe; and no explanations for gravity, the dark matter in the universe, neutrino masses, the number of particle generations, etc. Because of these shortcomings, there is considerable incentive to search for evidence for new, non-SM physics phenomena that might provide important clues about what a new, beyond the SM theory (BSM) might look like. Although the center-of-mass energies that BESIII can access are far below the energy frontier, searches for new, BSM physics are an important component of its research program. This report reviews some of the highlights from BESIII’s searches for signs of new, BSM physics by: measuring rates for processes that the SM predicts to be forbidden or very rare; searching for non-SM particles such as dark photons; performing precision tests of SM predictions; and looking for violations of the discrete symmetries C and CP in processes for which the SM expectations are immeasurably small. 相似文献
33.
Stephen J. Preece Christopher Bramah Duncan Mason 《European Journal of Sport Science》2019,19(6):784-792
The biomechanical profile of high-level endurance runners may represent a useful model that could be used for developing training programmes designed to improve running style. This study, therefore, sought to compare the biomechanical characteristics of high-performance and recreational runners. Kinematic and kinetic measurements were taken during overground running from a cohort of 14 high-performance (8 male) and 14 recreational (8 male) runners, at four speeds ranging from 3.3 to 5.6?m?s?1. Two-way ANOVA analysis was then used to explore group and speed effects and principal component analysis used to explore the interdependence of the tested variables. The data showed the high-performance runners to have a gait style characterised by an increased vertical velocity of the centre of mass and a flight time that was 11% longer than the recreational group. The high-performance group were also observed to adopt a forefoot strike pattern, to contact the ground with their foot closer to their body and to have a larger ankle moment. Importantly, although observed group differences were mostly independent of speed, the tested variables showed a high degree of interdependence suggesting an underlying unitary phenomenon. This is the first study to compare high-performance and recreational runners across a full range of kinematic and kinetic variables. The results suggest that high-performance runners maintain stride length with a prolonged aerial phase, rather than by landing with a more extended knee. These findings motivate future intervention studies that should investigate whether recreational runners could benefit from instruction to decrease shank inclination at foot contact. 相似文献
34.
35.
36.
37.
38.
Stephen E. Mawdsley 《Cultural and Social History》2016,13(2):249-265
In the late 1950s, a health charity, known as the National Foundation for Infantile Paralysis (March of Dimes), organized American teens into volunteer divisions to fight polio, as well as tame adult anxieties surrounding juvenile delinquency. The alliance that developed permitted the NFIP to increase its influence and revenue, while granting teens an opportunity to assert their cultural power and challenge negative stereotypes. Although the NFIP nurtured and at times dominated the relationship, young volunteers joined for their own reasons and shaped the program to suit their own aspirations and interests. 相似文献
39.
Stephen P Bailey Laureen Brown Elizabeth K Bailey 《Cardiopulmonary Physical Therapy Journal》2008,19(1):3-10
Individuals with chronic obstructive pulmonary disease (COPD) have been shown to benefit from participation in pulmonary rehabilitation (PR) programs that include exercise training and education. Purpose: To examine the relationship between improvements in 6 minute walk distance and perceived quality of life in individuals with COPD following completion of a PR program. Methods: The records of 139 individuals completing a PR program (3 times a week for 8 weeks) were retrospectively examined. Prior to entry and upon completion of the program each individual completed a 6 minute walk test (6MWT), the SF-36 Health survey, and the UCSD Shortness of Breath Questionnaire (SOB). SF-36 results were analyzed according to 8 subscales [Physical Functioning (PF), Role Physical (RF), Bodily Pain (BP), General Health (GH), Vitality (V), Social Functioning (SF), Role Emotional (RE), and Mental Health (MH)]. Results: PR resulted in significant improvements in 6MWTdistance (Pre = 845 ± 37 ft, Post = 1127 ± 32 ft, p < 0.001), PF (p < 0.001), RF (p = 0.001), Vitality (p = 0.002), SF (p < 0.001), RE (p = 0.037), MH (p < 0.001) and SOB (Pre = 53 ± 2, Post = 47 ± 2, p < 0.001). The change in 6MWT distance was not related to changes in PF (r = 0.17), RF (r = 0.03), GH (r = 0.03), Vitality (r = −0.001), SF (r = 0.01), RE (r = 0.06), MH (r = −0.04) or SOB (r = 0.12). The magnitude of improvement in 6MWT distance (68%) was much greater than that observed in PF (15%), RF (16%), GH (6%), VT (18%), SF (20%), RE (14%), MH (14%), or SOB (8%). Conclusions: PR has a positive impact on 6 minute walk distance and perceived quality of life in individuals with COPD; however, changes in 6 minute walk distance appear to have no relationship to changes in perceived quality of life. 相似文献
40.
The highly unsteady flow around a rowing blade in motion is examined using a three-dimensional computational fluid dynamics
(CFD) model which accounts for the interaction of the blade with the free surface of the water. The model is validated using
previous experimental results for quarter-scale blades held stationary near the surface in a water flume. Steady-state drag
and lift coefficients from the quarter-scale blade flume simulation are compared to those from a simulation of the more realistic
case of a full-scale blade in open water. The model is then modified to accommodate blade motion by simulating the unsteady
motion of the rowing shell moving through the water, and the sweep of the oar blade with respect to the shell. Qualitatively,
the motion of the free surface around the blade during a stroke shows a realistic agreement with the actual deformation encountered
during rowing. Drag and lift coefficients calculated for the blade during a stroke show that the transient hydrodynamic behaviour
of the blade in motion differs substantially from the stationary case. 相似文献