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81.
The international political economy of the hack: A closer look at markets for cybersecurity software
This article examines the development of hacking and cybersecurity software packages as commodities, based on an international political economy of vendors and clients operating in the interstices of international law. Offensive hacking and defensive cybersecurity tools offer new means for surveillance of critics, journalists, and human rights workers, especially in corrupt or authoritarian political systems. The article provides a case study of the Hacking Team, an international “cybersecurity” firm offering spyware and surveillance systems to government security agencies, which was itself hacked and “doxed” in 2015. The leak of documents contributes new knowledge of an international political economy for software products, which exploits the digital rights of targets and which could further undermine general Internet security. 相似文献
82.
Jaymee R. Shell Shawn M. K. Robbins Philippe C. Dixon Philippe J. Renaud René A. Turcotte Tom Wu 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(3):313-324
The forward skating start is a fundamental skill for male and female ice hockey players. However, performance differences by athlete’s sex cannot be fully explained by physiological variables; hence, other factors such as skating technique warrant examination. Therefore, the purpose of this study was to evaluate the body movement kinematics of ice hockey skating starts between elite male and female ice hockey participants. Male (n = 9) and female (n = 10) elite ice hockey players performed five forward skating start accelerations. An 18-camera motion capture system placed on the arena ice surface captured full-body kinematics during the first seven skating start steps within 15 meters. Males’ maximum skating speeds were greater than females. Skating technique sex differences were noted: in particular, females presented ~10° lower hip abduction throughout skating stance as well as ~10° greater knee extension at initial ice stance contact, conspicuously followed by a brief cessation in knee extension at the moment of ice contact, not evident in male skaters. Further study is warranted to explain why these skating technique differences exist in relation to factors such as differences in training, equipment, performance level, and anthropometrics. 相似文献
83.
Scott J. Pedersen Paul D. Cooley Vaughan J. Cruickshank 《Physical Education & Sport Pedagogy》2017,22(3):246-256
Background: The advent of technology use in physical education is upon us. But the implications of using exergames as a substitute for traditional physical education instruction for some students raise questions. Although exergames have the potential to increase energy expenditure and motivation in some children, it is less clear whether they can provide skill acquisition benefits that are similar to those found in traditional physical education.Purpose: In a previous experiment from our laboratory, we found that deliberate practice can significantly reduce the planning time required for lateral arm movements. The purpose of this study was to determine if exergames can produce a similar effect, by reducing the processing time required for children to initiate arm movements to the contralateral and ipsilateral space.Participants and setting: Thirty children (boys?=?15, girls?=?15), between the ages of 7 and 12 years, participated in a pre- and post-test each taking 30?min and one 30?min treatment session in a university laboratory.Research design: A repeated measures design was employed to test the effects of deliberate laterality practice on processing speed. Children were randomly assigned (n?=?10) to either a Nintendo Wii tennis contralateral movement experimental group, Nintendo Wii bowling ipsilateral movement experimental group, or handheld video-game control group. Each child participated in one 30?min treatment session.Data collection: Upper extremity choice reaction time (RT) was measured through 27 goal-directed aiming movements for each arm separately, during the pre-test and post-test. The stimulus–response trials occurred in three randomly presented directions (ipsilateral, contralateral, and midline).Data analysis: A 3 (treatment group)?×?2 (age group)?×?2 (test)?×?3 (direction) mixed design analysis of variance with repeated measures on the last two factors was used to test for significant differences, with an alpha level set at 0.05.Findings: There were no significant treatment effects on RT across all groups indicating that a short bout of exergame training was unsuccessful in improving lateral movement processing.Conclusions: Deliberate laterality practice using exergames did not improve the motor processing speed of lateral arm movements in the same manner of traditional physical education as indicated by our previous research. Explanations as to why exergames do not exhibit the same positive transfer for skill acquisition as traditional physical education instruction are discussed within this paper. 相似文献
84.
Ann M. Swartz Nora E. Miller Young IK Cho Whitney A. Welch Scott J. Strath 《European Journal of Sport Science》2017,17(2):222-230
The aim of this study is to determine changes in sedentary behaviour in response to extensive aerobic exercise training. Participants included adults who self-selected to run a marathon. Sedentary behaviour, total activity counts and physical activity (PA) intensity were assessed (Actigraph GT3X) for seven consecutive days during seven assessment periods (?3, ?2, and ?1 month prior to the marathon, within 2 weeks of the marathon, and +1, +2, and +3 months after the marathon). Models were fitted with multiple imputation data using the STATA mi module. Random intercept generalized least squares (GLS) regression models were used to determine change in sedentary behaviour with seven waves of repeated measures. Results: Twenty-three individuals (mean?±?Sx: 34.4?±?2.1y, 23.0?±?1.9% fat, 15 women, 8 men) completed the study. Marathon finishing times ranged from 185 to 344 minutes (253.2?±?9.6 minutes). Total counts in the vertical axis were 1,729,414 lower one month after the race, compared with two months prior to the race (peak training). Furthermore, counts per minute decreased by 252.7 counts·minute?1 during that same time period. Daily sedentary behaviour did not change over the seven assessment periods, after accounting for age, gender, per cent body fat, wear time, marathon finishing time, and previous marathon experience. This prospective study supports the notion that PA and sedentary behaviours are distinct, showing that sedentary behaviour was not impacted by high levels of aerobic training. 相似文献
85.
Understanding factors that motivate young athletes to continue participation in sport can help key stakeholders cultivate an environment that fosters long-term participation. This investigation sought to determine the performance and participation factors that influenced continued participation in junior cricket. Administration-level data were collected each annual season across a seven-year period by a community-level junior cricket association in Australia and analysed to identify the performance and participation-based predictors of player retention. All players were males aged <16 years. Players were categorised according to whether they remained in (or departed from) the association at the end of each playing season. A multivariate logistic regression model with a stepwise variable selection was employed to identify significant independent predictors of player retention. The number of innings batted and overs bowled were significant participation-related contributors to junior cricket player retention. Performance factors such as the number of wickets taken and the number of runs scored also significantly influenced player retention. Finally, team age group, the number of previous seasons played and age were also significant factors in player retention. This demonstrates that sufficient opportunity for children to participate in the game and expression of skills competence are key factors for retention in cricket. 相似文献
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Abstract The following paper should be seen as an addition to that provided in the Proceedings of the 7th ICTE.’ For reasons of brevity, it does not deal to any large extent with the background to the project, but details the progress of a study into the effects of introducing laptops into primary (elementary) school. The project has provided every pupil in one class with a laptop computer and has tracked the use being made of it as a curriculum tool for writing. The second phase of the project is under way, with a completion date of April 1991. 相似文献
90.