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591.
Racetubes, a conventional system employing hollow glass tubes, are typically used for monitoring circadian rhythms from the model filamentous fungus, Neurospora crassa. However, a major technical limitation in using a conventional system is that racetubes are not amenable for real-time gas perturbations. In this work, we demonstrate a simple microfluidic device combined with real-time gas perturbations for monitoring circadian rhythms in Neurospora crassa using bioluminescence assays. The developed platform is a useful toolbox for investigating molecular responses under various gas conditions for Neurospora and can also be applied to other microorganisms.  相似文献   
592.
Abstract

Few studies have focused on the effect of posture during sprint start. The aim of this study was to measure the effect of the modification of horizontal distance between the blocks during sprint start on three dimensional (3D) joint angular velocity. Nine trained sprinters started using three different starting positions (bunched, medium and elongated). They were equipped with 63 passive reflective markers, and an opto-electronic Motion Analysis® system was used to collect the 3D marker trajectories. During the pushing phase on the blocks, norm of the joint angular velocity (NJAV), 3D Euler angular velocity (EAV) and pushing time on the blocks were calculated. The results demonstrated that the decrease of the block spacing induces an opposite effect on the angular velocity of joints of the lower and the upper limbs. The NJAV of the upper limbs is greater in the bunched start, whereas the NJAV of the lower limbs is smaller. The modifications of NJAV were due to a combination of the movement of the joints in the different degrees of freedom. The medium start seems to be the best compromise because it leads, in a short pushing time, to a combination of optimal joint velocities for upper and lower segments.  相似文献   
593.
ABSTRACT

This study aimed to evaluate whether an individualised sprint-training program was more effective in improving sprint performance in elite team-sport players compared to a generalised sprint-training program. Seventeen elite female handball players (23 ± 3 y, 177 ± 7 cm, 73 ± 6 kg) performed two weekly sprint training sessions over eight weeks in addition to their regular handball practice. An individualised training group (ITG, n = 9) performed a targeted sprint-training program based on their horizontal force-velocity profile from the pre-training test. Within ITG, players displaying the lowest, highest and mid-level force-velocity slope values relative to body mass were assigned to a resisted, an assisted or a mixed sprint-training program (resisted sprinting in the first half and assisted sprinting in the second half of the intervention period), respectively. A control group (CG, n = 8) performed a generalised sprint-training program. Both groups improved 30-m sprint performance by ~1% (small effect) and maximal velocity sprinting by ~2% (moderate effect). Trivial or small effect magnitudes were observed for mechanical outputs related to horizontal force- or power production. All between-group differences were trivial. In conclusion, individualised sprint-training was no more effective in improving sprint performance than a generalised sprint-training program.  相似文献   
594.
Abstract

A frequently occurring situation in college and professional football is that of a team catching up through two touchdowns after trailing by 14 points, with the game outcome being determined by the extra-point plays. For leagues allowing two-point converts, an optimal point-after strategy exists under quite reasonable assumptions, and depends upon the relative utility to the team of a win, tie, or loss and the probability of success with a (one-point) kick as opposed to a (two-point) run/pass. We illustrate with reference to the January 1984 Orange Bowl game, where the favored team followed a possibly suboptimal strategy, losing the game and the national championship.  相似文献   
595.
Members of a social group possess a shared social identity, which is individually represented as the group prototype. The prototype is the individual cognitive representation of all attributes, which best describes the group from the group members’ point of view. The aim of the study was to gather those attributes provided by group members of a soccer team and subsequently to describe and categorize them by means of a content analysis. Using one single open question, a total of 1581 attributes were assessed through n?=?278 soccer players (67?% male; M?=?23.5 years, SD?=?5.0 years) from 20 soccer teams. The data analysis was based on the qualitative content analysis described by Mayring (2010). Results show that the attributes mentioned by the team members can be divided into four distinct categories (social, psychological, sport specific, ecological). These categories result from intragroup synchronisations. Future research should examine which categories and subcategories seem to best represent the prototype in soccer teams.  相似文献   
596.
This paper explores the hypothesis that embedding a laboratory activity into a virtual environment can provide a richer experimental context and hence improve the understanding of the relationship between a theoretical model and the real world, particularly in terms of the model's strengths and weaknesses. While an identified learning objective of laboratories is to support the understanding of the relationship between models and reality, the paper illustrates that this understanding is hindered by inherently limited experiments and that there is scope for improvement. Despite the contextualisation of learning activities having been shown to support learning objectives in many fields, there is traditionally little contextual information presented during laboratory experimentation. The paper argues that the enhancing laboratory activity with contextual information affords an opportunity to improve students’ understanding of the relationship between the theoretical model and the experiment (which is effectively a proxy for the complex real world), thereby improving their understanding of the relationship between the model and reality. The authors propose that these improvements can be achieved by setting remote laboratories within context-rich virtual worlds.  相似文献   
597.
This article examines with whom political journalists interact on Twitter and what information they share. These relations are explored by combining a content analysis and a network analysis of interaction patterns. The activities published on journalists’ personal accounts are studied. Prior research has shown that elite journalists, in particular, mainly seek to remain gatekeepers and tend to normalize emerging communication spaces. Only one-quarter of the parliamentary correspondents in the German Federal Press Conference had an individual Twitter profile as of February 2014. The content analysis of all tweets published during a week in March 2014 (N?=?2210) reveals that German political journalists clearly normalize Twitter to fit existing practices: the journalists mostly tweeted about publicly relevant communication and reported in an information-oriented style. Transparency was limited on their topics of interest, and they did not provide direct opportunities for the audience to become more active in the news-creation process. The network analysis shows that the correspondents especially incorporated politicians into their regular circle of contacts. Nevertheless, the interaction networks were clearly dominated by exchanges between journalists. In this way, journalists’ tweets allow us to observe expert talks rather than encouraging users to participate in a discussion.  相似文献   
598.

Implementing peer feedback in revisions is a complex process involving first planning to fix problems and then actual implementing feedback through revisions. Both phases are influenced by features of the peer feedback itself, but potentially in different ways, and yet prior research has not examined their separate role in planning or the mediating role of planning in the relationship of feedback features and implementation. We build on a process model to investigate whether feedback features had differing relationships to plans to ignore or act on feedback versus actual implementation of feedback in the revision, and whether planning mediated the relationship of feedback features and actual implementation. Source data consisted of peer feedback comments received, revision plans made, and revisions implemented by 125 US high school students given a shared writing assignment. Comments were coded for feedback features and implementation in the revision. Multiple regression analyses revealed that having a comment containing a specific solution or a general suggestion predicted revision plans whereas having a comment containing an explanation predicted actual implementation. Planning mediated the relationship to actual implementation for the two feedback features predicting plans, suggestion and solution. Implications for practice are discussed.

  相似文献   
599.

The theory of Expansive learning and the change laboratory (CL) methodology has been developed and applied in many studies on workplace learning and educational change. There are fewer studies made on small-scale interventions, exploring the longitudinal development of expansive learning in an educational change effort. This article examines a CL intervention performed in an upper secondary school in Sweden, with a small group of teachers engaged in a participatory design project. By identifying and analysing the relationship of the seven learning actions posited by the theory of expansive learning, the aim was to contribute to the discussion of the CL methodology and the empirical usability of the theory. The results showed that the seven expansive learning actions functioned as analytical tools to map the teachers learning and development, but the analysis also showed many deviations, disruptions and occurrence of practical actions of design in the process. This challenge the notions of cyclicity and ascension in the theory of expansive learning. Cyclicity might be desirable but not necessary for expansive learning which questions the need to first grasp the problem at a conceptual level before generating concrete solutions. The Findings in this study suggests the opposite; that the entanglement and parallel movement between the abstract and the concrete was a driving force for the teachers expansive learning and the design of new curricular units.

  相似文献   
600.
Opening up educational paths and especially decoupling educational courses and final school qualifications are seen as important aspects of the modernization of Swiss education. The study presented here investigates to what extent this de-linking actually took place in the case of the Swiss canton Freiburg. 525 pupils from German-speaking schools were observed in their progress from the end of primary school (year 6) to the transfer into the upper secondary level Gymnasium (year 10) or into alternative educational routes. Indeed, almost half of the young people, who went to the Gymnasium, previously studied at a middle-level general secondary school and not the preparatory Progymnasium; a strong indication of decoupling. Furthermore, the study shows that entry into the upper secondary level Gymnasium is still possible for pupils despite weak performance at primary level. Irrespective of the evidence for an opening of the education system, the findings also show that attending a Progymnasium has a significant effect on school biographies. The chance of transferring into the upper secondary level Gymnasium is twice as high for graduates, who attended a Progymnasium, as for comparative pupils, who did not. Additionally, a privileged social background correlates with a high chance of entry into the upper secondary level Gymnasium.  相似文献   
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