全文获取类型
收费全文 | 8685篇 |
免费 | 135篇 |
国内免费 | 10篇 |
专业分类
教育 | 6402篇 |
科学研究 | 499篇 |
各国文化 | 160篇 |
体育 | 756篇 |
综合类 | 5篇 |
文化理论 | 136篇 |
信息传播 | 872篇 |
出版年
2023年 | 21篇 |
2022年 | 43篇 |
2021年 | 93篇 |
2020年 | 201篇 |
2019年 | 265篇 |
2018年 | 321篇 |
2017年 | 361篇 |
2016年 | 336篇 |
2015年 | 211篇 |
2014年 | 275篇 |
2013年 | 1857篇 |
2012年 | 258篇 |
2011年 | 268篇 |
2010年 | 217篇 |
2009年 | 221篇 |
2008年 | 271篇 |
2007年 | 240篇 |
2006年 | 220篇 |
2005年 | 224篇 |
2004年 | 185篇 |
2003年 | 202篇 |
2002年 | 193篇 |
2001年 | 150篇 |
2000年 | 138篇 |
1999年 | 103篇 |
1998年 | 89篇 |
1997年 | 123篇 |
1996年 | 121篇 |
1995年 | 96篇 |
1994年 | 96篇 |
1993年 | 84篇 |
1992年 | 100篇 |
1991年 | 91篇 |
1990年 | 82篇 |
1989年 | 76篇 |
1988年 | 76篇 |
1987年 | 55篇 |
1986年 | 78篇 |
1985年 | 76篇 |
1984年 | 73篇 |
1983年 | 76篇 |
1982年 | 69篇 |
1981年 | 58篇 |
1980年 | 49篇 |
1979年 | 68篇 |
1978年 | 56篇 |
1977年 | 44篇 |
1976年 | 37篇 |
1975年 | 21篇 |
1974年 | 19篇 |
排序方式: 共有8830条查询结果,搜索用时 15 毫秒
31.
Michael Rushton 《Journal of Cultural Economics》2008,32(4):293-300
This paper was presented at the symposium dedicated to the 25th anniversary of the publication of Patrons Despite Themselves: Taxpayers and Arts Policy (Feld et al. 1983), held by the Association for Cultural Economics International, Boston, June 2008. It considers alternative
means of providing indirect tax-based state support of the arts, such as the use of tax credits as opposed to tax deductions
for charitable contributions, matching grants, and support applied to specific projects. It also considers the problem of
broad-based changes to tax policy that have unintended consequences for arts organizations.
相似文献
32.
33.
Using data on the ‘career’ paths of one thousand ‘leading scientists’ from 1450 to 1900, what is conventionally called the
‘rise of modern science’ is mapped as a changing geography of scientific practice in urban networks. Four distinctive networks
of scientific practice are identified. A primate network centred on Padua and central and northern Italy in the sixteenth
century expands across the Alps to become a polycentric network in the seventeenth century, which in turn dissipates into
a weak polycentric network in the eighteenth century. The nineteenth century marks a huge change of scale as a primate network
centred on Berlin and dominated by German-speaking universities. These geographies are interpreted as core-producing processes
in Wallerstein’s modern world-system; the rise of modern scientific practice is central to the development of structures of
knowledge that relate to, but do not mirror, material changes in the system.
相似文献
David M. EvansEmail: |
34.
35.
36.
37.
Stephen P. Timoshenko 《Journal of The Franklin Institute》1943,235(4):327-349
38.
Stephen L. Yelon 《Psychology in the schools》1969,6(2):155-157
39.
BackgroundIndividuals with diabetes have greater central arterial stiffness, wave reflections, and hemodynamics, all of which promote the accelerated cardiovascular pathology seen in this population. Acute aerobic exercise has been shown to be an effective strategy for reducing central arterial stiffness, wave reflections, and hemodynamics in healthy individuals; however, the effects of acute aerobic exercise in reducing these outcomes is not well established in people with diabetes. Recently, implementation of high-intensity interval exercise (HIIE) has shown superior improvements in cardiovascular health outcomes when compared to traditional aerobic exercise. Yet, the effect of HIIE on the aforementioned outcomes in people with diabetes is not known. The purpose of this study was to (i) describe the central arterial stiffness, wave reflections, and hemodynamic responses to a bout of HIIE and moderate-intensity continuous exercise (MICE) in adults with diabetes; and (ii) compare the effects of HIIE and MICE on the aforementioned outcomes.MethodsA total of 24 adult men and women (aged 29–59 years old) with type 1 (n = 12) and type 2 (n = 12) diabetes participated in a randomized cross-over study. All participants completed the following protocols: (i) HIIE: cycling for 4 × 4 min at 85%–95% of heart rate peak (HRpeak), interspersed with 3 min of active recovery at 60%–70%HRpeak; (ii) MICE: 33 min of continuous cycling at 60%–70%HRpeak; and (iii) control (CON): lying quietly in a supine position for 30 min.ResultsA significant group × time effect was found for changes in central systolic blood pressure (F = 3.20, p = 0.01) with a transient reduction for the HIIE group but not for the MICE or CON groups. There was a significant group × time effect for changes in augmentation index at a heart rate of 75 beats/min (F = 2.32, p = 0.04) with a decrease following for HIIE and MICE but not for CON. For all other measures of central arterial stiffness and hemodynamics, no significant changes were observed (p > 0.05).ConclusionA bout of HIIE appears to lead to a greater transient reduction in central systolic blood pressure than the reduction observed following MICE; however, both HIIE and MICE improved augmentation index at a heart rate of 75 beats/min in people with diabetes. There was no significant difference in response to HIIE and MICE in all outcomes. This provides preliminary evidence on the role of HIIE on such outcomes in people with diabetes. 相似文献
40.
The WISC-R scores for groups of children identified by school personnel as needing special education services were factor analyzed according to type of classification. WISC-R factor loadings were obtained for the scores of children labeled Learning Disabled, Educable Mentally Impaired, and Emotionally Impaired, as well as groups labeled Other and None. Overall, results show the WISC-R to be factorially similar for all groups, with two principal factors emerging which correspond to the Verbal-Performance structure of the test. Significance tests among mean scale scores and IQ scores yielded few meaningful differences across groups. 相似文献