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41.
Regarding the phenomenon of mood improvements through physical exercise, secondary analyses indicate that improvements can hardly be generalised. Rather, personal and situational factors need to be taken into consideration in order to define the effects in a more precise manner. This contribution investigates to what extent explicit motives and goals of individuals in middle adulthood can be considered as personal moderators of mood changes. Five exercise programmes were developed in a quasi-experimental design and were conducted over a 3-month intervention period. These programmes were based on the “motive-based types of sportsperson” (Sudeck, Lehnert & Conzelmann, 2011), which define groups of individuals with similar motive and goal profiles. One hundred and thirty-three individuals participated in either a programme tailor-made to their motive and goal profile or in a non-tailored programme. The influence of this motive-based tailoring was investigated based on the mood dimensions of valence, calmness and positive activation using handheld PCs during and after exercise sessions. Results indicate a moderating influence of explicit motives and goals. This moderation was however not a general one but rather depended on the exercise programmes’ specific goals and content as well as on individuals’ goals regarding recreation. These findings point towards a systematic consideration of explicit motives and goals in the planning of health and leisure sport programmes.  相似文献   
42.
The speed at which a player can swing a bat is central to the games of baseball and softball, determining, to a large extent, the hit speed of the ball. Experimental and analytical studies of bat swing speed were conducted with particular emphasis on the influence of bat moment of inertia on swing speed. Two distinct sets of experiments measured the swing speed of colege baseball and fast-pitch softball players using weighted rods and modified bats. The swing targets included flexible targets, balls on a tee and machine pitched balls. Internal mass alterations provided a range of inertial properties. The average measured speeds, from 22 to 31 m s−1, are consistent with previous studies. Bat speed approximately correlates with the moment of inertia of the bat about a vertical axis of rotation through the batter's body, the speed generally decreasing as this moment of inertia increases. The analytical model assumes pure rotation of the batter/bat system about a vertical axis through the batter's body. Aerodynamic drag of the batter's arms and the bat is included in the model. The independent variable is bat moment of inertia about the rotation axis. There is reasonable agreement between the model and the measured speeds. Detailed differences between the two suggest the importance of additional degrees of freedom in determining swing speed.  相似文献   
43.
The aims of this study were: (1) to identify the exercise intensity that corresponds to the maximal lactate steady state in adolescent endurance-trained runners; (2) to identify any differences between the sexes; and (3) to compare the maximal lactate steady state with commonly cited fixed blood lactate reference parameters. Sixteen boys and nine girls volunteered to participate in the study. They were first tested using a stepwise incremental treadmill protocol to establish the blood lactate profile and peak oxygen uptake ([Vdot]O2). Running speeds corresponding to fixed whole blood lactate concentrations of 2.0, 2.5 and 4.0?mmol?·?l?1 were calculated using linear interpolation. The maximal lactate steady state was determined from four separate 20-min constant-speed treadmill runs. The maximal lactate steady state was defined as the fastest running speed, to the nearest 0.5?km?·?h?1, where the change in blood lactate concentration between 10 and 20?min was?<0.5?mmol?·?l?1. Although the boys had to run faster than the girls to elicit the maximal lactate steady state (15.7 vs 14.3?km?·?h?1, P?<0.01), once the data were expressed relative to percent peak [Vdot]O2 (85 and 85%, respectively) and percent peak heart rate (92 and 94%, respectively), there were no differences between the sexes (P?>0.05). The running speed and percent peak [Vdot]O2 at the maximal lactate steady state were not different to those corresponding to the fixed blood lactate concentrations of 2.0 and 2.5?mmol?·?l?1 (P?>0.05), but were both lower than those at the 4.0?mmol?·?l?1 concentration (P?<0.05). In conclusion, the maximal lactate steady state corresponded to a similar relative exercise intensity as that reported in adult athletes. The running speed, percent peak [Vdot]O2 and percent peak heart rate at the maximal lactate steady state are approximated by the fixed blood lactate concentration of 2.5?mmol?·?l?1 measured during an incremental treadmill test in boys and girls.  相似文献   
44.
Abstract

This study examined the influence of pitch dimensions in small-sided soccer games in shaping opportunities for performers to maintain ball possession, pass to teammates and shoot at goal. Fifteen amateur standard male participants (M = 21.87, σ = 1.96 years) played 5 v 5 small-sided soccer games in three varying pitch conditions (28 m × 14 m, 40 m × 20 m and 52 m × 26 m). Thirty sequences of play in each condition were selected for digitisation using TACTO software, allowing the capture of bi-dimensional displacement coordinate data of all players and the ball. The values of interpersonal distance between all attackers and immediate defenders and the relative distances of defenders to intercept a shot and a pass were computed as dependent variables. Results showed existence of fewer opportunities to maintain ball possession on smaller pitches, compared to medium and larger pitches. Conversely, the different dimensions set to the pitch did not influence opportunities for players to shoot at goal, or to perform passes to other teammates. By examining the specific spatial–temporal relationships of players and key-task constraints, the data from this study explain how effects of manipulating pitch dimensions of small-sided games might enhance opportunities for acquiring specific movement and decision-making skills.  相似文献   
45.
This article examines the content and methodology of studies on Tai Chi as a sport in health care. We investigate the concept behind the rather simple name “Tai Chi,” concluding that this concept is manifold and highly variable. How did researchers deal with this variability when studying the effects of Tai Chi as a health-care intervention? We then explore how scientific research on Tai Chi has been conducted to date and draw the interim conclusion that the variability was barely taken into consideration. Our analysis of seven Tai Chi interventions reveals that two interventions referred to as Tai Chi may differ considerably in their content. The variability poses difficulty in repeating the intervention and drawing causal inferences. This problem is discussed in the current literature under the term “complexity in health-care interventions.” On the basis of a summary of this debate, we discuss the challenge of researching Tai Chi from a complex perspective—with the aim of achieving solid results that can be repeated.  相似文献   
46.
Visual art is one of the fields where, according to Bourdieu, culture is used to reproduce the class structure. Like other items in the cultural repertoire, paintings, as major examples of visual art, imply social divisions in how they are engaged with by artists, critics and audiences. Within the Bourdieusian framework, cultural engagements with paintings are interpreted as indicators of social position, since appreciation depends on a trained capacity in the family and the educational system, which is often inaccessible to less powerful sections of the population. This would imply that the sorts of paintings favoured by working-class people differ from those preferred by the middle or upper classes. More recent studies have contested the view that a gulf exists between the art tastes of different classes in ways that reproduce the class structure. The argument of the omnivore thesis that distinctions between more popular and legitimate tastes have become blurred has predominantly been based on empirical references in the field of music. This article explores this thesis on the basis of data about visual arts in the Cultural Capital and Social Exclusion project. While some differences continue to be connected to social divisions of income, education and occupational groups, important similarities are found across the board, and certain significant differences appear to relate to factors other than social class, such as ethnicity, age and gender. It is also significant that some people appear disconnected from and disinterested in paintings.  相似文献   
47.
48.
西方国家教师知识研究的演变与启示   总被引:6,自引:0,他引:6  
西方国家对教学的研究从教师的行为转向了教师的认知,而对教师认知的研究也从对教师决定、感知、思维等的研究转向了对教师知识的研究。教师的知识并不是抽象的、孤立的、离散的,而是各种类型的知识复杂地交织在一起的。目前,我国教师教育的课程改革不仅仅是课程数量的增加或减少,更重要的是通过课程内容的改革,加强学科专业课程之间的联系,通过教育实践性课程和教学案例学习实践性知识,从而整合职前教师所学的各种课程知识,使其更好地在教学中发挥作用。  相似文献   
49.
The system of higher education in the USA comprises the undergraduate programs of the colleges and the graduate programs in research universities. This distinction has no equivalent in Germany. The idea of elite education is connected exclusively with the colleges. Its meaning and functions are demonstrated with an analysis of the criteria which are used for the ranking of higher education institutions. The ranking of the colleges is addressed to the students and is based on indicators, which give expression above all to the educational priorities of the students and the alumni. The ranking of the graduate programs focuses on specific academic programs and is addressed to the members of the various academic fields and to their prospective students. A few rankings cover whole educational institutions and serve to inform the higher educational management. We use these data to identity the specifics of outstanding research universities and their role in American higher education.  相似文献   
50.
ABSTRACT

The objective of this study was to create a valid, self-reported, game-specific soccer competence scale. A structural model of perceived competence, performance measures and motivation was tested as the basis for the scale. A total of 1321 soccer players (261 females, 1060 males) ranging from 12 to 15 years (13.4 ± 1.0 years) participated in the study. They completed the Perceived Game-Specific Soccer Competence Scale (PGSSCS), self-assessments of tactical skills and motivation, as well as technical and speed and agility tests. Results of factor analyses, tests of internal consistency and correlations between PGSSCS subscales, performance measures and motivation supported the reliability and validity of the PGSSCS. The scale can be considered a suitable instrument to assess perceived game-specific competence among young soccer players.  相似文献   
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