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   16168篇
  免费   154篇
  国内免费   15篇
教育   10519篇
科学研究   2785篇
各国文化   143篇
体育   1116篇
综合类   14篇
文化理论   174篇
信息传播   1586篇
  2021年   140篇
  2020年   194篇
  2019年   291篇
  2018年   464篇
  2017年   464篇
  2016年   474篇
  2015年   334篇
  2014年   343篇
  2013年   2545篇
  2012年   449篇
  2011年   449篇
  2010年   330篇
  2009年   264篇
  2008年   306篇
  2007年   301篇
  2006年   235篇
  2005年   871篇
  2004年   655篇
  2003年   468篇
  2002年   303篇
  2001年   264篇
  2000年   259篇
  1999年   213篇
  1998年   124篇
  1997年   128篇
  1996年   145篇
  1995年   113篇
  1994年   119篇
  1993年   132篇
  1992年   153篇
  1991年   142篇
  1990年   161篇
  1989年   169篇
  1988年   128篇
  1987年   125篇
  1986年   157篇
  1985年   160篇
  1984年   141篇
  1983年   130篇
  1982年   113篇
  1981年   102篇
  1980年   102篇
  1979年   134篇
  1978年   109篇
  1977年   102篇
  1976年   98篇
  1974年   101篇
  1973年   86篇
  1972年   77篇
  1971年   94篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
111.
The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.  相似文献   
112.
Research indicates that instructing athlete’s to focus on bodily movements (internal focus of attention [IFA]) may hinder performance, whereas instructing them to focus on the movement outcome (external focus of attention [EFA]) often enhances performance. Despite the importance of instructions in striking combat sports, limited research has examined the influence of IFA and EFA on performance in well-trained combat athletes. This study investigated the effects of different instructional cues on punching velocity (m · s?1) and normalised impact forces (N · kg?1) among intermediate (n = 8) and expert (n = 7) competitive boxers and kickboxers. Athletes completed three rounds of 12 maximal effort punches delivered to a punching integrator on three separate days. Day one was a familiarisation session with only control instructions provided. In the following two days athletes randomly received IFA, EFA or control instructions prior to each of the three rounds. Athletes punching with EFA were 4% faster and 5% more forceful than IFA (< 0.05), and 2% faster and 3% more forceful than control (< 0.05). Furthermore, experts punched 11% faster and with 13% greater force compared with intermediate athletes (< 0.05). EFA led to a positive effect on punching performance and should be favoured over IFA and control instructions.  相似文献   
113.
114.
115.
Research suggests that spatial ability may predict success in complex disciplines including anatomy, where mastery requires a firm understanding of the intricate relationships occurring along the course of veins, arteries, and nerves, as they traverse through and around bones, muscles, and organs. Debate exists on the malleability of spatial ability, and some suggest that spatial ability can be enhanced through training. It is hypothesized that spatial ability can be trained in low-performing individuals through visual guidance. To address this, training was completed through a visual guidance protocol. This protocol was based on eye-movement patterns of high-performing individuals, collected via eye-tracking as they completed an Electronic Mental Rotations Test (EMRT). The effects of guidance were evaluated using 33 individuals with low mental rotation ability, in a counterbalanced crossover design. Individuals were placed in one of two treatment groups (late or early guidance) and completed both a guided, and an unguided EMRT. A third group (no guidance/control) completed two unguided EMRTs. All groups demonstrated an increase in EMRT scores on their second test (P < 0.001); however, an interaction was observed between treatment and test iteration (P = 0.024). The effect of guidance on scores was contingent on when the guidance was applied. When guidance was applied early, scores were significantly greater than expected (P = 0.028). These findings suggest that by guiding individuals with low mental rotation ability “where” to look early in training, better search approaches may be adopted, yielding improvements in spatial reasoning scores. It is proposed that visual guidance may be applied in spatial fields, such as STEMM (science, technology, engineering, mathematics and medicine), surgery, and anatomy to improve student's interpretation of visual content. Anat Sci Educ. © 2018 American Association of Anatomists.  相似文献   
116.
ABSTRACT

Due to budget constraints, schools in the United States have increasingly turned to community arts organizations for support. School-community arts partnership stakeholders collaborate because of shared missions to provide students with valuable arts learning experiences. Investigations of these initiatives indicate that these partnerships improve arts learning opportunities and increase public support and resources for arts education. However, not much is known about the experiences and perspectives of the arts organizations that participate in these partnerships. Coordinating collective efforts with a multitude of institutions and interests poses challenges. In this study, we examine survey data collected from arts organization administrators who participated in a large-scale school-community arts partnership initiative. We find that these organizations are generally positive about their impacts on students’ educational outcomes, but there is substantial variation in these views. We also find that organizations differ in their levels of support for these collective efforts. Sources of this variation appear to be attributable to organizations’ preexisting resources and extent to which they are established. While this difference in levels of support is potentially inevitable, we find evidence that the operations handled by the “backbone” organization, i.e. the initiative’s facilitators and overseers, can significantly influence organizations’ levels of support for these efforts. Organizations are more likely to support these collaborative efforts when they believe the backbone organization ensures transparency with initiative operations, provides regular, effective communication, and effectively resolves competing priorities.  相似文献   
117.
Virtual and Augmented Realities are advancing technologies that are becoming more popular in gaming and programming communities. However, virtual reality has been in development for decades. As libraries are often at the forefront of offering new and advancing technologies to their communities, virtual and augmented reality programs have become new additions to library services. While gaming is the prominent use of these technologies, virtual and augmented reality affords many educational opportunities. Mississippi State University Libraries have recently added a virtual/augmented reality lab as part of its library program.  相似文献   
118.
The purpose of this study was to examine the factorial invariance of the Abbreviated Neighborhood Environment Walkability Scale (NEWS-A) across subgroups based on demographic, health-related, behavioral, and environmental characteristics among Nurses’ Health Study participants (N = 2,919; age M = 73.0, SD = 6.9 years) living in California, Massachusetts, and Pennsylvania. A series of multigroup confirmatory factor analyses were conducted to evaluate increasingly restrictive hypotheses of factorial invariance. Factorial invariance was supported across age, walking limitations, and neighborhood walking. Only partial scalar invariance was supported across state residence and neighborhood population density. This evidence provides support for using the NEWS-A with older women of different ages, who have different degrees of walking limitations, and who engage in different amounts of neighborhood walking. Partial scalar invariance suggests that researchers should be cautious when using the NEWS-A to compare older adults living in different states and neighborhoods with different levels of population density.  相似文献   
119.
120.
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