全文获取类型
收费全文 | 466篇 |
免费 | 10篇 |
专业分类
教育 | 334篇 |
科学研究 | 17篇 |
各国文化 | 13篇 |
体育 | 65篇 |
综合类 | 1篇 |
文化理论 | 21篇 |
信息传播 | 25篇 |
出版年
2023年 | 4篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 14篇 |
2019年 | 28篇 |
2018年 | 26篇 |
2017年 | 27篇 |
2016年 | 33篇 |
2015年 | 22篇 |
2014年 | 17篇 |
2013年 | 95篇 |
2012年 | 12篇 |
2011年 | 11篇 |
2010年 | 11篇 |
2009年 | 7篇 |
2008年 | 13篇 |
2007年 | 15篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有476条查询结果,搜索用时 15 毫秒
441.
In this paper, identification of discrete-time power spectra of multi-input/multi-output (MIMO) systems in innovation models from output-only time-domain measurements is considered.A hybrid identification algorithm unifying mixed norm minimization with subspace estimation method is proposed. The proposed algorithm first estimates a covariance matrix from measurements. A significant dimension reduction is achieved in this step. Next, a regularized nuclear norm optimization problem is solved to enforce sparsity on the selection of most parsimonious model structure. A modification of the covariance estimates in the proposed algorithm generates yet another algorithm capable of handling data records with sequentially and intermittently missing values. The new and the modified identification algorithms are tested on a numerical study and a real-life application example concerned with the estimation of joint power spectral density (PSD) of parallel road tracks. 相似文献
442.
Maria Helena Martins Maria Leonor Borges Teresa Gonçalves 《International Journal of Inclusive Education》2018,22(5):527-542
In this article, we present data concerning the inclusion of students with disabilities in higher education (HE) at a Portuguese university. This research is part of a wider project designed to understand the trajectories and experiences of students with disabilities at the University of Algarve. This exploratory study raises questions about inclusion and discusses this concept based on the perspectives of academic and non-academic staff. A qualitative approach was used to provide an informative exploration of attitudes towards inclusive education and recommendations for promoting best practices therein. Data were collected using semi-structured interviews. We found positive perceptions of university staff members about the inclusion of the students with disabilities. However, more effort is needed to provide these students with opportunities to continue their academic career in HE and to promote inclusion, personal development and participation in social and economic life. Although inclusive education is on political and educational agendas, the perception of disabilities as deficits prevails. The findings of this study, therefore, reveal that changes must be implemented to effectively adopt the social and educational model of disability. 相似文献
443.
Gabriel R. Neto Jefferson S. Novaes Verônica P. Salerno Michel M. Gonçalves Gilmário R. Batista Maria S. Cirilo-Sousa 《Journal of sports sciences》2018,36(1):104-110
The aim of this study was to compare the effect of low-load resistance exercise (LLRE) with continuous and intermittent blood flow restriction (BFR) on the creatine kinase (CK), lactate dehydrogenase (LDH), protein carbonyl (PC), thiobarbituric acid-reactive substance (TBARS) and uric acid (UA) levels in military men. The study included 10 recreationally trained men aged 19 ± 0.82 years who underwent the following experimental protocols in random order on separate days (72–96 h): 4 LLRE sessions at a 20% 1RM (one-repetition maximum [1RM]) with continuous BFR (LLRE + CBFR); 4 LLRE sessions at 20% 1RM with intermittent BFR (LLRE + IBFR) and 4 high-intensity resistance exercise (HIRE) sessions at 80% 1RM. The CK and LDH (markers of muscle damage) levels were measured before exercise (BE), 24 h post-exercise and 48 h post-exercise, and the PC, TBARS and UA (markers of oxidative stress) levels were measured BE and immediately after each exercise session. There was a significant increase in CK in the HIRE 24 post-exercise samples compared with the LLRE + CBFR and LLRE + IBFR (P = 0.035, P = 0.036, respectively), as well as between HIRE 48 post-exercise and LLRE + CBFR (P = 0.049). Additionally, there was a significant increase in CK in the LLRE + CBFR samples BE and immediately after each exercise (Δ = 21.9%) and in the HIRE samples BE and immediately after each exercise, BE and 24 post-exercise, and BE and 48 post-exercise (Δ values of 35%, 177.6%, and 177.6%, respectively). However, there were no significant changes in LDH, PC, TBARS, and UA between the protocols (P > 0.05). Therefore, a physical exercise session with continuous or intermittent BFR did not promote muscle damage; moreover, neither protocol seemed to affect the oxidative stress markers. 相似文献
444.
Gerfeson Mendonça Alex Antonio Florindo Cassiano Ricardo Rech Delma Katiana Silva de Freitas José Cazuza de Farias Júnior 《Journal of sports sciences》2018,36(9):1068-1075
Little is known about the association between environmental characteristics and types of physical activity in adolescents in a Latin American context. The aim of this study was to examine the association between perceived neighborhood environmental characteristics and different types of physical activity in 2,874 adolescents from Joao Pessoa, Paraiba State, Northeastern Brazil. The types of activity measured by questionnaire (≥10 min/day) included sports, physical exercises, active commuting and recreational activities. Neighborhood characteristics were measured by a 15-item scale. Multilevel analyses showed that adolescents who reported “having places they liked to go to” (OR = 1.41; 95%CI: 1.10–1.79) and “places with opportunities to practice” (OR = 1.29; 95%CI: 1.01–1.65) were more likely to play sports. “Seeing interesting things while walking” (OR = 1.24; 95%CI: 1.01–1.53) and “Seeing other adolescents engaged in physical activity” (OR = 1.47; 95%CI: 1,05–2,06) were associated with exercises. “Seeing other adolescents engaged in physical activity” (OR = 1.47; 95%CI: 1.18–1.82), “the neighborhood is not violent” (OR = 1.29; 95%CI: 1.04–1.60) and “having places they like to go to” (OR = 1.59; 95%CI: 1.13–2.25) were positively associated and “places with opportunities to practice” (OR = 0.79; 95%CI: 0.63–0.98) inversely related to active commuting. “Seeing other adolescents engaged in physical activities” (OR = 1.31; 95%CI: 1.05–1.63) and “seeing interesting things while walking” (OR = 1.26; 95%CI: 1.02–1.56) were associated with recreational activities. Neighborhood environmental characteristics associated with the physical activity vary with the type of practices adopted by adolescents. 相似文献
445.
Differential Learning as a Key Training Approach to Improve Creative and Tactical Behavior in Soccer
Sara Santos Diogo Coutinho Bruno Gonçalves Wolfgang Schöllhorn Jaime Sampaio Nuno Leite 《Research quarterly for exercise and sport》2018,89(1):11-24
Purpose: The aim of this study was to identify the effects of a differential-learning program, embedded in small-sided games, on the creative and tactical behavior of youth soccer players. Forty players from under-13 (U13) and under-15 (U15) were allocated into control and experimental groups and were tested using a randomized pretest to posttest design using small-sided games situations. Method: The experimental group participated in a 5-month differential-learning program embodied in small-sided games situations, while the control group participated in a typical small-sided games training program. In-game creativity was assessed through notational analyses of the creative components, and the players’ positional data were used to compute tactical-derived variables. Results: The findings suggested that differential learning facilitated the development of creative components, mainly concerning attempts (U13, small; U15, small), versatility (U13, moderate; U15, small), and originality (U13, unclear; U15, small) of players’ actions. Likewise, the differential-learning approach provided a decrease in fails during the game in both experimental groups (moderate). Moreover, differential learning seemed to favor regularity in pitch-positioning behavior for the distance between players’ dyads (U13, small; U15, small), the distance to the team target (U13, moderate; U15, small), and the distance to the opponent target (U13, moderate; U15, small). Conclusions: The differential-learning program stressed creative and positional behavior in both age groups with a distinct magnitude of effects, with the U13 players demonstrating higher improvements over the U15 players. Overall, these findings confirmed that the technical variability promoted by differential learning nurtures regularity of positioning behavior. 相似文献
446.
Mounir Landolsi Lazhar Labiadh Fayçal Zarrouk Khaled Maaref Slaheddine Ghannouchi Zouhair Tabka 《European Journal of Sport Science》2018,18(9):1208-1216
The aims of this study were to (1) propose a method for evaluating shot-putters mechanical power, (2) investigate the relationship between mechanical work of hand action force (WHAF), peak power output (PPO) of different limbs and shot-put performance and (3) show which of these two parameters (WHAF, PPO) were the most appropriate to characterize the explosive abilities of the shot-putter. Twelve junior right-handed shot-putters, practised glide technique shot-put throwers (personal best?=?13.57 ± 1.72 m), participated in this study. Arm and leg force-velocity tests were performed to measure PPO. Kinematic analysis was conducted during a shot-putting event in regular conditions to quantify the WHAF at the release moment and shot-put performance. Significant correlations were found between absolute arm and leg PPO with upper and lower muscle volumes (r?=?.67; p?=?.03; r?=?.76; p?=?.01; r?=?.74, p?=?.01; r?=?.65, p?=?.04). Positive relationships were recorded between absolute arm and leg PPO and shot-put performance (r?=?.67, p?=?.02; r?=?.81, p?=?.004, respectively). Shot-put performance was also closely related to the WHAF (r?=?.93, p?=?.0001) and release velocity parameter (r?=?.86, p?=?.001). The present results confirm that force-velocity test and WHAF constitute useful tools for assessing mechanical power in throwing. The WHAF could be considered as more suitable than force-velocity test. 相似文献
447.
Huot-Marchand F Nesi X Sidney M Alberty M Pelayo P 《Sports biomechanics / International Society of Biomechanics in Sports》2005,4(1):89-99
The aim of this study was to analyse the variations of stroking parameters (speed, stroke length, stroke rate, and stroke index) associated with the 200 m front crawl competitive performance improvement. Two races completed by 17 top swimmers were analysed in the 200 m freestyle final of French or European championships, each final being separated by two years. All the swimmers' performances were bettered in the second race (mean +/- SD: 113.44 +/- 2.50 vs 111.78 +/- 2.71 s; p < 0.01) and were associated with a significant increase of stroke rate without variation of average stroke length and stroke index values (p > 0.05). Swimmers emphasized the first part of the race, with higher speed in the first three lengths, higher stroke rate in the first two lengths and lower stroke length in the first one. Stroke length and stroke rate variations were highly correlated (r = 0.98; p < 0.05). In 11 of the 17 swimmers, the improvement was concomitant with a decrease in stroke length and an increase in stroke rate. Only one swimmer's improvement was associated with a substantial increase in stroke length. These results highlighted that stroke length and stroke index cannot be considered as the only parameters linked to improvement in a 200 m crawl in adult swimmers competing at high standard. Moreover, an increase in stroke rate associated with a slight decrease in stroke length should not be considered as ineffective, especially at top standard. 相似文献
448.
European Journal of Psychology of Education - There are two kinds of preferential representations. They are connected on the one hand to the degree of typicality of the instance in relation to the... 相似文献
449.
450.