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   13387篇
  免费   48篇
  国内免费   3篇
教育   10411篇
科学研究   1330篇
各国文化   36篇
体育   457篇
文化理论   405篇
信息传播   799篇
  2024年   3篇
  2023年   20篇
  2022年   24篇
  2021年   41篇
  2020年   66篇
  2019年   107篇
  2018年   2284篇
  2017年   2183篇
  2016年   1667篇
  2015年   161篇
  2014年   203篇
  2013年   458篇
  2012年   305篇
  2011年   765篇
  2010年   901篇
  2009年   494篇
  2008年   685篇
  2007年   1198篇
  2006年   116篇
  2005年   437篇
  2004年   479篇
  2003年   394篇
  2002年   157篇
  2001年   30篇
  2000年   37篇
  1999年   21篇
  1998年   18篇
  1997年   26篇
  1996年   11篇
  1995年   11篇
  1994年   6篇
  1993年   5篇
  1992年   6篇
  1991年   18篇
  1990年   7篇
  1989年   9篇
  1988年   6篇
  1987年   5篇
  1986年   6篇
  1985年   7篇
  1984年   3篇
  1983年   3篇
  1981年   7篇
  1980年   3篇
  1979年   6篇
  1978年   3篇
  1977年   4篇
  1976年   4篇
  1957年   2篇
  1926年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Though there is a long tradition of band members quitting the group or taking a hiatus, the rock group as an organization to produce music continues to be both popular and economically viable. The research question addressed in this paper is whether or not it is a good idea to quit or take a hiatus from the group. We begin with a discussion of the framework for understanding why groups are formed and why they may be difficult to keep together. We then discuss differences between groups in the decade of the 1960s versus today. We argue that there is something unique about the output of the group even with the changes in the structure of contracts, compensation, and consumer focus on the artist that explain the resilience of the rock band as an organizational form within which to create music. We compare the charting success of bands that have members leave the group with the charting success of the members who left the group. We identified the groups in five representative years: 1965, 1975, 1985, 1995, and 2005. We then analyzed the entire Billboard Hot 100 charting careers of those groups and the artists who quit those groups. Our main finding is that when charting success is divided equally among members, going solo pays off—there is a clear economic rationale because solo acts have greater average charting success than the original bands they started in. The other ensuing side projects: duos, collaborations, and other groups are not as lucrative as the original bands. These findings are valid for members of charting groups from each of the 5 years examined. Despite the difficulties in keeping a rock band together, there are fewer band breakups today and remaining with the group generally results in a longer and more productive charting career. Thus, the rock group remains an important organization for producing contemporary music. However, there remains a compelling incentive to go solo. Superstars may benefit from solo projects, but for the average, non-superstar group member, in many circumstances it is better for the band to stay together if the income is divided equally.  相似文献   
132.
133.
Are universities able to operate as strategic actors? An organisational sociology based approach supported by a comparative field research project identifies three types of social, cultural and cognitive processes that play a decisive role in building and implementing local capabilities required to mobilise a strategic capacity. The paper identifies how much these processes are present in the four ideal-types of universities defined by crossing their reputation and their metrics-based performance. Such a meso deterministic perspective suggests that universities may position themselves as proactive actors or principals, and not just as agents of national reforms and political demands. Nevertheless, their ability to do it varies according to their type. The paper also explores the implications of such findings for institutional leadership and steering policymakers.  相似文献   
134.
There is a crisis of valuation practices in the current academic life sciences, triggered by unsustainable growth and “hyper-competition.” Quantitative metrics in evaluating researchers are seen as replacing deeper considerations of the quality and novelty of work, as well as substantive care for the societal implications of research. Junior researchers are frequently mentioned as those most strongly affected by these dynamics. However, their own perceptions of these issues are much less frequently considered. This paper aims at contributing to a better understanding of the interplay between how research is valued and how young researchers learn to live, work and produce knowledge within academia. We thus analyze how PhD students and postdocs in the Austrian life sciences ascribe worth to people, objects and practices as they talk about their own present and future lives in research. We draw on literature from the field of valuation studies and its interest in how actors refer to different forms of valuation to account for their actions. We explore how young researchers are socialized into different valuation practices in different stages of their growing into science. Introducing the concept of “regimes of valuation” we show that PhD students relate to a wider evaluative repertoire while postdocs base their decisions on one dominant regime of valuing research. In conclusion, we discuss the implications of these findings for the epistemic and social development of the life sciences, and for other scientific fields.  相似文献   
135.
This paper proposes a learning-based method for text detection and text segmentation in natural scene images. First, the input image is decomposed into multiple connected-components (CCs) by Niblack clustering algorithm. Then all the CCs including text CCs and non-text CCs are verified on their text features by a 2-stage classification module, where most non-text CCs are discarded by an attentional cascade classifier and remaining CCs are further verified by an SVM. All the accepted CCs are output to result in text only binary image. Experiments with many images in different scenes showed satisfactory performance of our proposed method.  相似文献   
136.
137.
In sports, fast and accurate execution of movements is required. It has been shown that implicitly learned movements might be less vulnerable than explicitly learned movements to stressful and fast changing circumstances that exist at the elite sports level. The present study provides insight in explicit and implicit motor learning in youth soccer players with different expertise levels. Twenty-seven youth elite soccer players and 25 non-elite soccer players (aged 10–12) performed a serial reaction time task (SRTT). In the SRTT, one of the sequences must be learned explicitly, the other was implicitly learned. No main effect of group was found for implicit and explicit learning on mean reaction time (MRT) and accuracy. However, for MRT, an interaction was found between learning condition, learning phase and group. Analyses showed no group effects for the explicit learning condition, but youth elite soccer players showed better learning in the implicit learning condition. In particular, during implicit motor learning youth elite soccer showed faster MRTs in the early learning phase and earlier reached asymptote performance in terms of MRT. Present findings may be important for sports because children with superior implicit learning abilities in early learning phases may be able to learn more (durable) motor skills in a shorter time period as compared to other children.  相似文献   
138.
Sports clubs depend on the pooling of resources by their members. The supportive distribution of the resources within a club is facilitated in particular by the effectiveness of incremental standards. A basic prerequisite for a fair distribution of resources is a minimum of community spirit among the members. Based on a nationwide survey of football clubs and an ordinal logistic regression model, factors were determined that reflect the extent of the community spirit within a club. The opening up of the club by payment to players and perceived problems with acquiring and binding of volunteers are associated with a reduction of community spirit. In contrast, the perception that the club activities can be continued in the long term shows a positive correlation to a highly developed community spirit.  相似文献   
139.
The application of advanced engineering to tennis racket design has influenced the nature of the sport. As a result, the International Tennis Federation has established rules to limit performance, with the aim of protecting the nature of the game. This paper illustrates how changes to the racket affect the player-racket system. The review integrates engineering and biomechanical issues related to tennis racket performance, covering the biomechanical characteristics of tennis strokes, tennis racket performance, the effect of racket parameters on ball rebound and biomechanical interactions. Racket properties influence the rebound of the ball. Ball rebound speed increases with frame stiffness and as string tension decreases. Reducing inter-string contacting forces increases rebound topspin. Historical trends and predictive modelling indicate swingweights of around 0.030–0.035 kg/m2 are best for high ball speed and accuracy. To fully understand the effect of their design changes, engineers should use impact conditions in their experiments, or models, which reflect those of actual tennis strokes. Sports engineers, therefore, benefit from working closely with biomechanists to ensure realistic impact conditions.  相似文献   
140.
A non-rotational (NR) shot is now a well-known scoring move in soccer. To execute the NR shot, it is necessary to deprive the ball of any rotational forces during the impact phase. To execute the NR shot, it is natural that the force vector acting from the foot would pass through the ball’s center of gravity; however, the coordinated motion of the lower limb joint’s angular displacement and the pelvis is still unclear. The aim of this study is to estimate the coordinated leg and pelvis motion during the NR shot as compared to that during instep kicking. Four right-leg dominant college league players were asked to perform a NR shot and an instep kick a total of 10 times each. Hip, knee, and ankle joint angular displacements in the sagittal plane and pelvis yaw and roll rotational motions during both types of kicks were calculated with 14 IR reflective markers using a 3D real-time motion analysis system with a 250-Hz sampling. The Euclidean distances of the joint space of the NR shot and the instep kick were also calculated to detect similarities in the coordinated motion of the lower limb. The results showed that the lower limb joint motions in the sagittal plane were not different; however, the pelvis roll and yaw motions were apparently different, and these phenomena could simulate a pendulum motion with changes in both the vertical and horizontal displacements. These results suggest that the coordinated motion of the lower limb joint’s angular displacement shows high similarity between the NR shot and the instep kick, and the pelvis roll and yaw synchronized orientation is essential for achieving the NR shot.  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