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   12116篇
  免费   116篇
  国内免费   11篇
教育   7783篇
科学研究   2207篇
各国文化   89篇
体育   947篇
综合类   5篇
文化理论   90篇
信息传播   1122篇
  2021年   118篇
  2020年   187篇
  2019年   291篇
  2018年   365篇
  2017年   338篇
  2016年   255篇
  2015年   196篇
  2014年   242篇
  2013年   2173篇
  2012年   261篇
  2011年   237篇
  2010年   197篇
  2009年   188篇
  2008年   184篇
  2007年   196篇
  2006年   151篇
  2005年   157篇
  2004年   143篇
  2003年   147篇
  2002年   133篇
  2001年   183篇
  2000年   183篇
  1999年   159篇
  1998年   87篇
  1997年   97篇
  1996年   113篇
  1995年   89篇
  1994年   97篇
  1993年   96篇
  1992年   138篇
  1991年   141篇
  1990年   147篇
  1989年   166篇
  1988年   122篇
  1987年   117篇
  1986年   158篇
  1985年   156篇
  1984年   130篇
  1983年   128篇
  1982年   115篇
  1981年   97篇
  1980年   104篇
  1979年   138篇
  1978年   122篇
  1977年   105篇
  1976年   103篇
  1974年   111篇
  1973年   92篇
  1972年   85篇
  1971年   109篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Lumbar-pelvic kinematics change in response to increasing rowing stroke rates, but little is known about the effect of incremental stroke rates on changes in joint kinetics and their implications for injury. The purpose of this study was to quantify the effects of incremental rowing intensities on lower limb and lumbar-pelvic kinetics. Twelve female rowers performed an incremental test on a rowing ergometer. Kinematic data of rowers’ ankle, knee, hip and lumbar-pelvic joints, as well as external forces at the handle, seat and foot-stretchers of the rowing machine were recorded. Inter-segmental moments and forces were calculated using inverse dynamics and were compared across stroke rates using repeated measures ANOVA. Rowers exhibited increases in peak ankle and L5/S1 extensor moments, reductions in peak knee moments and no change in peak hip moments, with respect to stroke rate. Large shear and compressive forces were seen at L5/S1 and increased with stroke rate (< 0.05). This coincided with increased levels of lumbar-pelvic flexion. High levels of lumbar-pelvic loading at higher stroke rates have implications with respect to injury and indicated that technique was declining, leading to increased lumbar-pelvic flexion. Such changes are not advantageous to performance and can potentially increase the risk of developing injuries.  相似文献   
92.
Motor performance is an important health resource. Review articles revealed a decline of motor performance of approximately 10?% between 1975 and 2006. In the past most of the data available for such comparisons came from ad hoc studies with non-standardized methods. Within the framework of the ”Motorik-Modul“ (MoMo) study as part of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), it is possible for the first time to directly compare two cohorts in the ages of 4–17 years in a nationally representative database for Germany. The aim of this article is to report changes in motor performance of children and adolescents in the time period 2003–2006 (cohort baseline n = 4528) compared to 2009–2012 (cohort wave 1, n = 2820). Overall, it is clearly shown that the motor performance of children and adolescents in Germany did not decrease within the observational period of 6 years. The comparison of mean values of the baseline cohort compared to those of wave 1 showed that 28 out of 52 mean values of the two cohorts with a high probability did not differ based on 95?% confidence intervals (CI). In 24 out of the 52 mean values positive changes could be noted based on the individual 95?% CI values. There were more positive changes in primary school aged children than in other age groups. Within these positive changes, most effect sizes were small to medium. The results indicate that recent activities aiming at elevating motor performance levels may have started to make an impact and should be expanded, also in secondary schools. The comparative cohort study presented in this article is currently being checked by the ongoing MoMo wave 2 survey of 2014–2017.  相似文献   
93.
94.
标记事务影响着学者们对思考与写作系统的采纳使用。程序性标记和表示性标记会阻碍这一进程的发展,描述性标记则通过简化机械性任务,让学者们将注意力集中于内容上的做法,以加快这一进程。  相似文献   
95.
This study examined the accuracy of self-attachment of the activPAL activity monitor. A convenience sample of 50 participants self-attached the monitor after being presented with written material only (WMO) and then written and video (WV) instructions; and completed a questionnaire regarding the acceptability of the instructional methods. Participants positioned the monitor lower than the instructed position on the thigh (WMO ?5.15 ± 2.75 cm, WV ?4.16 ± 2.15 cm; p = .008 difference) and approximately 2 cm laterally from the thigh midline (WMO 1.90 ± 0.92 cm; WV 2.08 ± 1.24 cm). The orientation of the device was positioned correctly along the midline (within < 1° of vertical). Acceptability was high for both instructional methods although preference was shown for the WV instruction. In conclusion, participants consistently self-attached the activPAL close to the intended placement with either instructional method. The addition of video instruction produced a slightly more accurate attachment and was preferred by the participants.  相似文献   
96.
The present study examined the sex-specific associations of moderate and vigorous physical activity (VPA) with physical fitness in 300 Japanese adolescents aged 12–14 years. Participants were asked to wear an accelerometer to evaluate physical activity (PA) levels of various intensities (i.e. moderate PA (MPA), 3–5.9 metabolic equivalents (METs); VPA, ≥6 METs; moderate to vigorous PA (MVPA), ≥3 METs). Eight fitness items were assessed (grip strength, bent-leg sit-up, sit-and-reach, side step, 50?m sprint, standing long jump, handball throw, and distance running) as part of the Japanese standardised fitness test. A fitness composite score was calculated using Japanese fitness norms, and participants were categorised according to their score from category A (most fit) to category E (least fit), with participants in categories D and E defined as having low fitness. It was found that for boys, accumulating more than 80.7?min/day of MVPA may reduce the probability of low fitness (odds ratio (ORs) [95% confidence interval (CI)]?=?0.17 [0.06–0.47], p?=?.001). For girls, accumulating only 8.4?min of VPA could reduce the likelihood of exhibiting low fitness (ORs [95% CI]?=?0.23 [0.05–0.89], p?=?.032). These results reveal that there are sex-specific differences in the relationship between PA and physical fitness in adolescents, suggesting that sex-specific PA recommendation may be needed to improve physical fitness in adolescents.  相似文献   
97.
There is conflicting evidence on the association between lower limb alignment characteristics and the incidence of running-related injury (RRI). Therefore, the primary aim of this study was to investigate the association between lower limb alignment characteristics and the incidence proportion of RRI in a convenience sample of recreational runners. A total of 89 recreational runners were included in this prospective cohort study. These participants had been running for at least six months and were injury-free at baseline. Lower limb alignment measurements were conducted in order to calculate lower limb discrepancy, Q-angle, subtalar angle and plantar index. All participants also answered a baseline and biweekly online surveys about their running routine, history of RRI and newly developed RRI over a period of 12 weeks. The prevalence of previous RRI and the 12-week incidence proportion of new RRI were calculated. Logistic regression analysis was performed to estimate the association between lower limb length discrepancy, Q-angle, subtalar angle and plantar ach index with the incidence proportion of RRI. The prevalence of previous RRI was 55.1% (n?=?49). The 12-week incidence proportion of new RRI was 27.0% (n?=?24). Muscle injuries and tendinopathies were the main types of RRI identified. The lower leg and the knee were the main anatomical regions affected. We did not find significant associations between lower limb length discrepancy, Q-angle, subtalar angle and plantar arch index and injury occurrence.  相似文献   
98.
Preschool managers’ responsibility for and leadership of systematic quality work has come to the fore in connection with changes made to the Swedish preschool curriculum. The aim of this study is to contribute to the understanding of preschool managers’ leadership and management of the systematic quality work in Swedish preschools with reference to three specific domains: (i) governance, leadership/management and organisation, (ii) content and methods and (iii) development work and collegiate learning. Using qualitative methods, 18 preschool managers’ perspectives of leading systematic quality work have been analysed in relation to previous research. The results show a tension between linear and interactive forms of governance in the systematic quality work, but also that knowledge gaps among the staff can lead to uncertainties that the preschool manager has to address. At the same time, the results show the diversity of and variation in how children’s development and increased proficiency are documented, while the documentation of the quality of the work focuses on learning environments rather than on teaching and teacher competence. In the study, there are traces of what can be characterised as leadership for learning. This needs to be investigated more closely using other methods in future research.  相似文献   
99.
This paper reveals the complex diversity that underpins ostensibly similar transnational education programmes (TNE), through a comparison of UK TNE in Malaysia and Hong Kong. It draws on data from two different yet cognate studies on the role of UK universities in delivering higher education in Asia. Some fine-grained and informative differences between the ways in which ‘value’ in TNE is constructed in different host contexts is revealed. The paper brings to light the ‘voices’ of TNE students and graduates, which are very seldom heard. The arguments adapt and extend the concepts of education as a positional good, and as cultural capital. For various instrumental, intrinsic and personal reasons the authors discuss in detail, UK TNE is more highly valued in Malaysia than in Hong Kong. The paper makes a wider contribution to knowledge on the changing landscape of international higher education and the impact on social and personal (dis)advantage.  相似文献   
100.
Control of beak opening (gape) and peck location was examined in pigeons. Feeding pecks showed accurate guidance that positioned the seed between the beaks. At the moment of contact with the seed, gape was proportional to seed diameter, although pecks with gape less than seed diameter were more frequent following an increase in seed size during a meal. There were no substantial differences between pigeons trained to keypeck with autoshaping and those trained with operant conditioning procedures. With either procedure, water reinforcement produced keypecks with the beak closed; seed reinforcers of different sizes produced means for gape proportional to the seed diameters. Black or white circular stimuli of different sizes projected as conditioning signals had little influence upon gape, but a greater percentage of responses was directed to white stimuli. These results indicate that visual stimuli elicit and orient the peck, whereas the adjustment of gape also involves the somatosensory stimuli provided during previous experience with a particular reinforcer or food type.  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