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11.
In this study, we investigated the adjustments to posture, kinematic and temporal characteristics of performance made by lower limb amputees during the last few strides in preparation for long jump take-off. Six male unilateral trans-femoral and seven male unilateral trans-tibial amputees competing in a World Championships final were filmed in the sagittal plane using a 100-Hz digital video camera positioned so that the last three strides to take-off were visible. After digitizing using a nine-segment model, a range of kinematic variables were computed to define technique characteristics. Both the trans-femoral and trans-tibial athletes appeared to achieve their reduction in centre of mass during the flight phase between strides, and did so mainly by extending the flight time by increasing stride length, achieved by a greater flexion of the hip joint of the touch-down leg. The trans-tibial athletes appeared to adopt a technique similar to that previously reported for able-bodied athletes. They lowered their centre of mass most on their second last stride (-1.6% of body height compared with -1.4% on the last stride) and used a flexed knee at take-off on the last stride, but they were less able to control their downward velocity at touch-down (-0.4 m x s(-1)). Both this and their restricted approach speed (8.9 m x s(-1) at touch-down), rather than technique limitations, influenced their jump performance. The trans-femoral athletes lowered their centre of mass most on the last stride (-2.3% of body height compared with -1.6% on the second last stride) and, as they were unable to flex their prosthetic knee sufficiently, achieved this by abducting their prosthetic leg during the support phase, which led to a large downward velocity at touch-down (-0.6 m x s(-1)). This, combined with their slower approach velocity (7.1 m x s(-1) at touch-down), restricted their performance.  相似文献   
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The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to "pull" on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.  相似文献   
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Nonprofessional library support staff traditionally hold what are considered to be low-paying, nonchallenging positions. These negative factors make retaining creative and productive employees difficult. This article outlines the approach taken at the Medical College of Georgia's Robert B. Greenblatt, M.D. Library to devise a structure of library staff positions that becomes progressively more demanding. A new nine-level Library Staff Classification Plan resulted. This plan also enables and encourages employees to acquire more skills and to accept more responsibility in order to qualify for higher-level library positions or to advance their present position to receive comparable rewards. The plan expresses the level of responsibilities expected, the employee qualifications desired, and lists representative duties across the spectrum of typical library tasks.  相似文献   
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Two studies are reported that used multiple measures of creativity to investigate creativity differences and correlates in arts and science students. The first study examined Divergent Thinking fluency, Self-Rated Creativity and Creative Achievement in matched groups of Art and Science students. Arts students scored higher than Science students on two of the three measures. Regression analysis indicated that the educational domain demographic variable was the most consistent predictor of all three measures of creativity. The second study compared natural science, social science and arts students on two performance and two preference measures of creativity, whilst controlling for the effects of general intelligence. Results indicated only Self-Rated Creativity displayed significant group differences, with the regression analysis suggesting a stronger role of personality variables. The differences between the groups and implications for the measurement of creativity are considered.  相似文献   
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This study aims to ascertain student and staff attitudes to and perceptions of audio feedback made available via the virtual learning environment (VLE) for summative assessment. Consistent with action research and reflective practice, this study identifies best practice, highlighting issues in relation to implementation with the intention of redesigning activities in the light of the findings. It utilises four case studies where audio feedback was provided to students using the Wimba voice authoring tool within Blackboard Learn+ for various types of summative assessment. The intention was to identify how and in what context audio feedback via the VLE is effective and why. The research was undertaken via a combination of techniques, including a student survey and staff reflective logs. The findings indicate that students liked the convenience, effectiveness, flexibility and personalised nature of this feedback, but raised concerns with some aspects of the technology. This paper also makes practical recommendations for the use of the feedback mechanism, focusing on the most effective use of the digital medium, and highlights directions for future research.  相似文献   
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The scientific performance of 64 political science, sociology and marketing departments in Romania is investigated with the aid of the g-index. The assessment of departments based on the g-index shows, within each of the three types of departments that make up the population of the study, a strong polarisation between top performers (very few) and weak performers (much more numerous). This alternative assessment is also found to be largely consistent with an official ranking of departments carried out in 2011 by the Ministry of Education. To conduct the evaluation of departments the individual scientific output of 1385 staff members working in the fields of political science, sociology and marketing is first determined with the aid of the ‘Publish or Perish’ software based on the Google Scholar database. Distinct department rankings are then created within each field using a successive (second-order) g-index.  相似文献   
20.

ICTs have been increasingly involved in teaching–learning processes due to the potential offered by the tools as well as to the set of demands derived from the political and health situations of the social environment. In this sense, the introduction of virtual campuses as complex systems that centralize the entire technological component that complements traditional teaching processes has meant a change of paradigm with repercussions at the teaching and pedagogical level. In this context, the purpose of this study aims to analyze students’ perception of the use of virtual campus and how to enhance the quality of the educational process using intelligent systems. For this purpose, 318 students that use virtual campus have been surveyed. The results show that there are three variables that predominantly influence the quality of teaching–learning processes using virtual campuses: frequent contact with teachers through the platform, the digital competence of the student, and the adaptation of training content to the students’ prior knowledge. This information can be useful, as it allows them to establish guidelines to guide the practices of their teaching teams in technological environments, guaranteeing the suitability of the teaching–learning process and improving the evaluation processes and the assessment of their own educational work.

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