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991.
International travel is an essential part of the life of elite athletes, both for competition and training. It is also becoming increasingly common among recreational sportspersons. Long-distance travel is associated with a group of transient negative effects, collectively referred to as 'travel fatigue', which result from anxiety about the journey, the change to an individual's daily routine, and dehydration due to time spent in the dry air of the aircraft cabin. Travel fatigue lasts for only a day or so, but for those who fly across several time zones, there are also the longer-lasting difficulties associated with 'jet lag'. The problems of jet lag can last for over a week if the flight crosses 10 time zones or more, and they can reduce performance and the motivation to train effectively. Knowledge of the properties of the body clock enables the cause of the difficulties to be understood (an unadjusted body clock), and forms the basis of using light in the new time zone to promote adjustment of the body clock. Sleep loss and its effects are important components of jet lag, and attempts to promote sleep by the use of melatonin and other hypnotics are also relevant. Sleep loss is also found in those who undertake challenges that involve long periods where the normal consolidated sleep of 8 h length is not possible. Advice on sleep regimens in such circumstances is given.  相似文献   
992.
993.
Abstract

Graded exercise tests are commonly used to assess peak physiological capacities of athletes. However, unlike time trials, these tests do not provide performance information. The aim of this study was to examine the peak physiological responses of female outrigger canoeists to a 1000-m ergometer time trial and compare the time-trial performance to two graded exercise tests performed at increments of 7.5 W each minute and 15 W each two minutes respectively. 17 trained female outrigger canoeists completed the time trial on an outrigger canoe ergometer with heart rate (HR), stroke rate, power output, and oxygen consumption ([Vdot]O2) determined every 15 s. The mean (± s) time-trial time was 359 ± 33 s, with a mean power output of 65 ± 16 W and mean stroke rate of 56 ± 4 strokes · min?1. Mean values for peak [Vdot]O2, peak heart rate, and mean heart rate were 3.17 ± 0.67 litres · min?1, 177 ± 11 beats · min?1, and 164 ± 12 beats · min?1 respectively. Compared with the graded exercise tests, the time-trial elicited similar values for peak heart rate, peak power output, peak blood lactate concentration, and peak [Vdot]O2. As a time trial is sport-specific and can simultaneously quantify sprint performance and peak physiological responses in outrigger canoeing, it is suggested that a time trial be used by coaches for crew selection as it doubles as a reliable performance measure and a protocol for monitoring peak aerobic capacity of female outrigger canoeists.  相似文献   
994.
Abstract

Twenty-four players from the 1st/2nd (elite) and 24 players from the 3rd/4th (non-elite) university football teams were recruited to evaluate the Loughborough Soccer Passing Test (LSPT) and Loughborough Soccer Shooting Test (LSST) as tools to assess soccer skill. The LSPT requires players to complete 16 passes as quickly as possible. The LSST requires players to pass, control, and shoot the ball to targets on a full-sized goal. Participants completed two main trials each separated by at least one day. During both trials, the participants were given practice efforts before recording the mean of the next two (LSPT) or 10 (LSST) attempts as the performance score. For the LSPT, the mean time taken, added penalty time, and overall performance time were less in the elite players (elite: 43.6 s, s = 3.8; non-elite: 52.5 s, s = 7.4; P = 0.0001). For the LSST, there was no difference in the mean points scored per shot between groups (elite: 1.34, s = 0.46; non-elite: 1.28, s = 0.53). However, the elite players had higher mean shot speed (elite: 80 km · h?1, s = 4.5; non-elite: 74 km · h?1, s = 4.2; P < 0.0001) and performed each shot sequence faster (elite: 7.87 s, s = 0.29; non-elite: 8.07 s, s = 0.35; P = 0.037) than the non-elite players. Performance on both tests was more repeatable in elite players. In conclusion, the LSPT and LSST are valid and reliable protocols to assess differences in soccer skill performance.  相似文献   
995.
ABSTRACT

Self-talk enhances physical performance. Nothing is known however about the way that a subtle grammatical difference in self-talk, using first or second person pronouns, may effect performance. As second person self-talk supports self-regulation in non-exercise populations, we hypothesized that 10 km cycling time-trial performance would be superior following second versus first person self-talk. Using a randomized, counterbalanced, crossover design, sixteen physically active males (Mage = 21.99, SD = 3.04 years) completed a familiarization visit followed by a 10 km time-trial during two separate experimental visits using first and second person self-talk. A paired t-test revealed that second person self-talk generated significantly faster time-trial performance than first person self-talk (p = .014). This was reflected in a significantly greater power output throughout the time-trial when using second person self-talk (p = .03), despite RPE remaining similar between conditions (p = .75). This is the first evidence that strategically using grammatical pronouns when implementing self-talk can influence physical performance providing practitioners with a new aspect to consider when developing interventions. We discussed findings in the context of a self-distancing phenomenon induced by the use second person pronouns.  相似文献   
996.
Abstract

The present experiment evaluated the effects of a 27-day sit up exercise training program on adipose cell size and adiposity. Fat biopsies were taken from the abdomen, subscapular, and gluteal sites by needle aspiration in 13 experimental and 6 control male subjects before and after a five days/week progressive training regimen. Day 1 consisted of 10 bouts of 10-sec exercise, 7 sit ups/bout, with 10-sec rest intervals; on day 27, 14 bouts of 30-sec exercise were performed, 24 sit ups/bout with 10-sec rest intervals. The total number of sit ups done was 5004. Fat cells were isolated using collagenase and photographed to determine cell diameter. Repeated measures ANOVA revealed significant decreases in cell diameter at the three biopsy sites (p<.01), but no significant differences in the rate of change (pre to post) in cell diameter between sites for the experimental and control groups (p>.05). Body weight, total body fat (underwater weighing), and fatfolds and girths remained unaltered. The results demonstrate that (1) the conventional sit up exercise does not preferentially reduce adipose cell size or subcutaneous fat thickness in the abdominal region to a greater extent compared to other adipose sites, and (2) significant changes in fat cell size may occur in the absence of changes in fatfolds, girths or total body composition.  相似文献   
997.
Abstract

This study evaluated the effects of a three-year exercise program on motor performance and cognitive processing speed of previously sedentary older women, ages 57–85. Variables tested were simple and choice reaction time (CRT), balance, sit and reach flexibility, shoulder flexibility, and grip strength. Subjects participated three times a week in exercise performance classes designed to meet American College of Sports Medicine guidelines. Results indicate that performance was significantly improved on all measures during the course of the study (p < .01) except for the sit and reach test (SRT), where significance was approached (p < .027), but not reached. A comparison of the exercise subjects with a comparable group of nonexercising control subjects revealed significant interactions between treatment and time on all variables except CRT and grip strength. Pretest to posttest scores of the exercise subjects tended to improve over the three-year period, whereas the scores of the control subjects declined. Improved reaction time indicated exercise is effective in reversing or at least slowing certain age-related declines in motor performance and in speed of cognitive processing.  相似文献   
998.
Abstract

One's achievement goal orientation (e.g., task, ego) is suggested to reflect a differential focus on skill mastery and performance outcome (Duda, 1992). Goal orientation has further been suggested to be an important observer characteristic in the observational learning of motor skills (McCullagh, Weiss, & Ross, 1989). This study assessed the relationship between goal orientation and a focus on form and outcome aspects of a motor skill demonstration with college students (N = 30) having low perceived ability, knowledge, and experience in tennis. Participants viewed several videotaped demonstrations of a correctly performed tennis forehand and then visual recognition and verbal recall accuracy of form and outcome task characteristics were assessed. A canonical correlation analysis revealed a nonsignificant relationship between goal orientation and recall and recognition of form and outcome task characteristics. These results provide preliminary evidence to suggest that goal orientation may not be an important observer characteristic in the learning phase of the modeling process. Also, achievement goal orientations may not be associated with a differential focus on skill mastery or performance outcome but instead remain a reflection of divergent processes of success evaluation.  相似文献   
999.
Abstract

Based on literature identifying movement imagery, observation, and execution to elicit similar areas of neural activity, research has demonstrated that movement imagery and observation successfully prime movement execution. To investigate whether movement and observation could prime ease of imaging from an external visual-imagery perspective, an internal visual-imagery perspective, and kinesthetic modality, 36 participants (M age = 20.58; SD = 3.11; 18 women and 18 men) completed an adapted version of the Movement Imagery Questionnaire-Revised under four modes of delivery (movement prime, external observation prime, internal observation prime, and image-only). The results revealed that ease of imaging was significantly greater during the movement and observation prime conditions compared to the image-only condition (p < .05). Specifically when priming external visual imagery and internal visual imagery, observation facilitated ease of imaging only when the perspective was congruent with the imagery perspective. The results support the use of movement and observation to facilitate ease of imaging, but highlight the importance of considering the visual perspective when using observation.  相似文献   
1000.
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