全文获取类型
收费全文 | 566篇 |
免费 | 6篇 |
专业分类
教育 | 386篇 |
科学研究 | 47篇 |
各国文化 | 6篇 |
体育 | 33篇 |
文化理论 | 26篇 |
信息传播 | 74篇 |
出版年
2021年 | 4篇 |
2020年 | 9篇 |
2019年 | 12篇 |
2018年 | 21篇 |
2017年 | 20篇 |
2016年 | 13篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 141篇 |
2012年 | 8篇 |
2011年 | 14篇 |
2010年 | 8篇 |
2009年 | 11篇 |
2008年 | 5篇 |
2007年 | 9篇 |
2006年 | 12篇 |
2005年 | 12篇 |
2004年 | 12篇 |
2003年 | 15篇 |
2002年 | 19篇 |
2001年 | 13篇 |
2000年 | 9篇 |
1999年 | 13篇 |
1998年 | 9篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 8篇 |
1987年 | 3篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1971年 | 6篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 4篇 |
1966年 | 4篇 |
1943年 | 2篇 |
排序方式: 共有572条查询结果,搜索用时 15 毫秒
11.
When kindergarten children began to self-record their own progress in skills targeted across the curriculum, there was a distinct increase in their rate of achieving these skills. It is argued that this has significant implications for a comprehensive, naturalistic evaluation in the classroom, with many benefits and few costs. 相似文献
12.
Singh PP Chandra A Mahdi F Roy A Sharma P 《Indian journal of clinical biochemistry : IJCB》2010,25(3):225-243
The antioxidants are essential molecules in human system but are not miracle molecules. They are neither performance enhancers
nor can prevent or cure diseases when taken in excess. Their supplemental value is debateable. In fact, many high quality
clinical trials on antioxidant supplement have shown no effect or adverse outcomes ranging from morbidity to all cause mortality.
Several Chochrane Meta-analysis and Markov Model techniques, which are presently best available statistical models to derive
conclusive answers for comparing large number of trials, support these claims. Nevertheless none of these statistical techniques
are flawless. Hence, more efforts are needed to develop perfect statistical model to analyze the pooled data and further double
blind, placebo controlled interventional clinical trials, which are gold standard, should be implicitly conducted to get explicit
answers. Superoxide dismutase (SOD), glutathione peroxidase and catalase are termed as primary antioxidants as these scavenge
superoxide anion and hydrogen peroxide. All these three enzymes are inducible enzymes, thereby inherently meaning that body
increases or decreases their activity as per requirement. Hence there is no need to attempt to manipulate their activity nor
have such efforts been clinically useful. SOD administration has been tried in some conditions especially in cancer and myocardial
infarction but has largely failed, probably because SOD is a large molecule and can not cross cell membrane. The dietary antioxidants,
including nutrient antioxidants are chain breaking antioxidants and in tandem with enzyme antioxidants temper the reactive
oxygen species (ROS) and reactive nitrogen species (RNS) within physiological limits. Since body is able to regulate its own
requirements of enzyme antioxidants, the diet must provide adequate quantity of non-enzymic antioxidants to meet the normal
requirements and provide protection in exigent condition. So far, there is no evidence that human tissues ever experience
the torrent of reactive species and that in chronic conditions with mildly enhanced generation of reactive species, the body
can meet them squarely if antioxidants defense system in tissues is biochemically optimized. We are not yet certain about
optimal levels of antioxidants in tissues. Two ways have been used to assess them: first by dietary intake and second by measuring
plasma levels. Lately determination of plasma/serum level of antioxidants is considered better index for diagnostic and prognostic
purposes. The recommended levels for vitamin A, E and C and beta carotene are 2.2–2.8 μmol/l; 27.5–30 μmol/l; 40–50 μmol/l
and 0.4–0.5 μmol/l, respectively. The requirement and recommended blood levels of other dietary antioxidants are not established.
The resolved issues are (1) essential to scavenge excess of radical species (2) participants in redox homeostasis (3) selective
antioxidants activity against radical species (4) there is no universal antioxidant and 5) therapeutic value in case of deficiency.
The overarching issues are (1) therapeutic value as adjuvant therapy in management of diseases (2) supplemental value in developing
population (3) selective interactivity of antioxidant in different tissues and on different substrates (4) quantitative contribution
in redox balance (5) mechanisms of adverse action on excess supplementation (6) advantages and disadvantages of prooxidant
behavior of antioxidants (7) behavior in cohorts with polymorphic differences (8) interaction and intervention in radiotherapy,
diabetes and diabetic complications and cardiovascular diseases (9) preventive behavior in neurological disorders (10) benefits
of non-nutrient dietary antioxidants (11) markers to assess optimized antioxidants status (12) assessment of benefits of supplementation
in alcoholics and heavy smokers. The unresolved and intriguing issues are (1) many compounds such as vitamin A and many others
possessing both antioxidant and non-antioxidant properties contribute to both the activities in vivo or exclusively only to
non-antioxidant activity and (2) since human tissues do not experience the surge of FR, whether there is any need to develop
stronger synthetic antioxidants. Theoretically such antioxidants may do more harm than good. 相似文献
13.
14.
15.
16.
Roy Rothwell 《Research Policy》1974,3(1):30-38
A brief and constructive criticism is offered of the recent study (see preceding paper) which successfully adopted and adapted the Sussex SAPPHO ‘pair comparison’ technique to the investigation of twelve success-failure pairs in the Hungarian electronics industry. Despite some differences in methodology and differences in the industrial and political environments in which the two studies were made, the results of the Hungarian SAPPHO and the Sussex SAPPHO are remarkably similar. 相似文献
17.
Keke Lai Samuel B. Green Roy Levy Ray E. Reichenberg Yuning Xu Marilyn S. Thompson 《Structural equation modeling》2016,23(4):491-506
Two models can be nonequivalent, but fit very similarly across a wide range of data sets. These near-equivalent models, like equivalent models, should be considered rival explanations for results of a study if they represent plausible explanations for the phenomenon of interest. Prior to conducting a study, researchers should evaluate plausible models that are alternatives to those hypothesized to evaluate whether they are near-equivalent or equivalent and, in so doing, address the adequacy of the study’s methodology. To assess the extent to which alternative models for a study are empirically distinguishable, we propose 5 indexes that quantify the degree of similarity in fit between 2 models across a specified universe of data sets. These indexes compare either the maximum likelihood fit function values or the residual covariance matrices of models. Illustrations are provided to support interpretations of these similarity indexes. 相似文献
18.
Dr. Joseph J. Roy 《Clearing house (Menasha, Wis.)》2013,86(6):275-276
Teachers can help minority children close the academic achievement gap in intermediate and middle school by combining literacy instruction and content-area material. This connection improves reading achievement and increases curriculum knowledge, even if students have previously experienced difficulty with primary school reading. Fortunately, upper-elementary and middle-level learners are still naturally curious, are developing cognitively, and have acquired some basic reading skills. Teachers can therefore extend students' previous learning by using a spiral curriculum, in which curricular concepts are introduced at an appropriate level and then revisited at more challenging levels. Teachers can also increase the academic complexity for students by using strategies that include picture books, word recognition skills, intensive subject matter, vocabulary in a meaningful context, Readers Theater, and after-school activities. 相似文献
19.
Roy Fisher 《Curriculum Journal》2013,24(2):253-277
This article provides an account of ‘three generations’ of the Business Education Council (BEC)/Business and Technician (later Technology) Education Council (BTEC) curriculum as implemented in further education colleges between 1979 and 1992. There is discussion of aspects of the underlying philosophy of BEC/BTEC, the structure and content of the programmes, skills, assessment, work experience, learning strategies, and aspects of monitoring and quality control. It is argued that BEC/BTEC, through a form of vocational progressivism, successfully transformed pedagogic practices in FE during the 1980s. The advent of the National Council for Vocational Qualifications, however, and the subsequent introduction of General Advanced Vocational Qualifications in 1993 effectively marked the end of the ‘BEC/BTEC’ era and the establishment of a more directly instrumentalist approach to vocational education. 相似文献
20.