全文获取类型
收费全文 | 15104篇 |
免费 | 170篇 |
国内免费 | 31篇 |
专业分类
教育 | 9723篇 |
科学研究 | 2651篇 |
各国文化 | 107篇 |
体育 | 1131篇 |
综合类 | 11篇 |
文化理论 | 104篇 |
信息传播 | 1578篇 |
出版年
2021年 | 135篇 |
2020年 | 216篇 |
2019年 | 328篇 |
2018年 | 416篇 |
2017年 | 427篇 |
2016年 | 336篇 |
2015年 | 257篇 |
2014年 | 343篇 |
2013年 | 2677篇 |
2012年 | 344篇 |
2011年 | 332篇 |
2010年 | 288篇 |
2009年 | 256篇 |
2008年 | 268篇 |
2007年 | 299篇 |
2006年 | 232篇 |
2005年 | 208篇 |
2004年 | 214篇 |
2003年 | 208篇 |
2002年 | 185篇 |
2001年 | 260篇 |
2000年 | 292篇 |
1999年 | 231篇 |
1998年 | 148篇 |
1997年 | 139篇 |
1996年 | 157篇 |
1995年 | 108篇 |
1994年 | 125篇 |
1993年 | 112篇 |
1992年 | 186篇 |
1991年 | 187篇 |
1990年 | 187篇 |
1989年 | 203篇 |
1988年 | 178篇 |
1987年 | 153篇 |
1986年 | 209篇 |
1985年 | 201篇 |
1984年 | 166篇 |
1983年 | 178篇 |
1982年 | 140篇 |
1981年 | 115篇 |
1980年 | 108篇 |
1979年 | 164篇 |
1978年 | 141篇 |
1977年 | 123篇 |
1976年 | 122篇 |
1975年 | 98篇 |
1974年 | 117篇 |
1973年 | 108篇 |
1971年 | 111篇 |
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
101.
102.
Cemal Ozemek Mitchell H. Whaley W. Holmes Finch Leonard A. Kaminsky 《European Journal of Sport Science》2017,17(5):563-570
There have been many conflicting observations between the linear or curvilinear decline in maximal heart rate (HRmax) with age. The aim of this study was to determine if linear or curvilinear equations would better describe the decline in HRmax with age in individuals of differing cardiorespiratory fitness (CRF) levels. Treadmill cardiopulmonary exercise test (CPX) results from participants (1510 men and 1134 women; 18–76 years) free of overt cardiovascular disease were retrospectively examined using cross-sectional and longitudinal study designs. Participants completing ≥2 CPX with ≥1 year between test dates were included in the longitudinal analysis (325 men and 150 women). Linear and quadratic regressions were applied to age and HRmax for the whole cohort and respective CRF groups (high, moderate, and low, relative to age and gender normative values). To test for differences among linear, quadratic, and polynomial equations, the change in R2 (cross-sectional analysis) and Bayesian information criterion (BIC) (longitudinal analysis) from the linear to the more complex models were calculated. The quadratic or polynomial regression in the cross-sectional analysis, marginally improved the variance in HRmax explained by age compared to the linear regression for the whole cohort (0.2%), moderate fit group (0.3%), and low fit group (0.8%). With no improvements in the high fit group. BIC did not improve for any CRF category in the longitudinal analysis. In conclusion, the minimal differences among linear, quadratic, and polynomial equations in the respective CRF groups, emphasizes the use of linear prediction equations to estimate HRmax. 相似文献
103.
Joshua H. Guy Andrew M. Edwards Catherine M. Miller Glen B. Deakin David B. Pyne 《Journal of sports sciences》2017,35(16):1622-1628
Prospective application of serum cytokines, lipopolysaccharide (LPS), and heat shock proteins (eHSPs) requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (7 day) reliability (at rest, n = 12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60-min cycling, 34.5°C and 70% RH, n = 20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin-6 (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and LPS. Test–retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-participant variation were IL-6 (19%, ±20%; CV, ±95% confidence limits (CL)) and LPS (23%, ±13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28–38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ±11%, P = < 0.001) and although CRP had a modest CV (12%, ±7%), it increased substantially post-exercise (P = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation. 相似文献
104.
105.
ABSTRACTThe literature on momentum is still undecided, with mixed results whether momentum exists or is only perceived to exist (“hot hand fallacy”). We explore whether momentum exists by looking at cases in which a basketball player has three consecutive free throws. A free throw is a well-defined task executed in a stable environment, allegedly giving momentum optimal chances to occur. Taking 14 NBA seasons we collected over 4500 three-free-throw sets (triplets). We obtained the outcomes of the shots as well as some additional variables about the player and the game: the player’s average free-throw percentage, home or away, and the game score and the quarter when the free throws were attempted. We first analyse the hit rates in the three shots and then proceed to regression analysis that also controls for the abovementioned variables. We address several concerns raised in the literature. All comparisons and analyses yield the same conclusion that there is no evidence for momentum in the data. 相似文献
106.
107.
Neural engineering is an emerging field of high relevance to students, teachers, and the general public. This Feature presents online resources that educators and scientists can use to introduce students to neural engineering and to integrate core ideas from the life sciences, physical sciences, social sciences, computer science, and engineering into the classroom. 相似文献
108.
The current study examined the link between academic enablers and different types of reading achievement measures. Academic enablers are skills and behaviors that support, or enable, students to perform well academically, such as engagement, interpersonal skills, motivation, and study skills. The sample in this study consisted of 61 third‐, fourth‐, and fifth‐grade students (54% male). Academic enablers were rated by classroom teachers via the Academic Competence Evaluation Scales (ACES; DiPerna & Elliott, 2000 ). Four different measures of reading achievement were included: classroom grades, global ratings of reading skills, standardized test scores, and Reading CBM scores. Results indicated that academic enablers were significantly related to each type of reading outcome. Academic enablers accounted for the greatest amount of variance for classroom grades (45%) and the least amount of variance in standardized test scores (11%). Results suggest that academic enablers are an important part of academic success in reading, particularly classroom grades, but when considering the variance accounted for by academic enablers, they alone are not likely to improve Reading CBM scores or standardized test scores. 相似文献
109.
Families immigrating to Australia face many challenges integrating into the educational system, including language barriers and interrupted schooling. We have qualitatively evaluated the educational concerns of Arabic migrants from Sudan and Iraq to Melbourne, Victoria, Australia, a city that receives a high percentage of Australia's immigrants. Using an interactive paradigm incorporating focus group discussions for thematic analysis, we concluded that the parents’ frame of reference for education was a more didactic style of learning. Parents viewed education as an essential part of the way forward for their children in Australia. However, it was stressful for them to try to cope with a new host nation's expectation of their involvement in their children's education while at the same time dealing with a language barrier. Professionals should look to empower parents with structural information about the key elements of the educational curriculum with minimal reliance on written technical language and match their expectations of parental involvement to the situation of the parents. 相似文献
110.
Dylan J.H.A. Henssen Loes van den Heuvel Guido De Jong Marc A.T.M. Vorstenbosch Anne-Marie van Cappellen van Walsum Marianne M. Van den Hurk Jan G.M. Kooloos Ronald H.M.A. Bartels 《Anatomical sciences education》2020,13(3):353-365
Neuroanatomy education is a challenging field which could benefit from modern innovations, such as augmented reality (AR) applications. This study investigates the differences on test scores, cognitive load, and motivation after neuroanatomy learning using AR applications or using cross-sections of the brain. Prior to two practical assignments, a pretest (extended matching questions, double-choice questions and a test on cross-sectional anatomy) and a mental rotation test (MRT) were completed. Sex and MRT scores were used to stratify students over the two groups. The two practical assignments were designed to study (1) general brain anatomy and (2) subcortical structures. Subsequently, participants completed a posttest similar to the pretest and a motivational questionnaire. Finally, a focus group interview was conducted to appraise participants’ perceptions. Medical and biomedical students (n = 31); 19 males (61.3%) and 12 females (38.7%), mean age 19.2 ± 1.7 years participated in this experiment. Students who worked with cross-sections (n = 16) showed significantly more improvement on test scores than students who worked with GreyMapp-AR (P = 0.035) (n = 15). Further analysis showed that this difference was primarily caused by significant improvement on the cross-sectional questions. Students in the cross-section group, moreover, experienced a significantly higher germane (P = 0.009) and extraneous cognitive load (P = 0.016) than students in the GreyMapp-AR group. No significant differences were found in motivational scores. To conclude, this study suggests that AR applications can play a role in future anatomy education as an add-on educational tool, especially in learning three-dimensional relations of anatomical structures. 相似文献