全文获取类型
收费全文 | 558篇 |
免费 | 18篇 |
专业分类
教育 | 431篇 |
科学研究 | 23篇 |
各国文化 | 14篇 |
体育 | 65篇 |
文化理论 | 11篇 |
信息传播 | 32篇 |
出版年
2023年 | 8篇 |
2022年 | 8篇 |
2021年 | 22篇 |
2020年 | 33篇 |
2019年 | 53篇 |
2018年 | 49篇 |
2017年 | 68篇 |
2016年 | 43篇 |
2015年 | 26篇 |
2014年 | 38篇 |
2013年 | 108篇 |
2012年 | 17篇 |
2011年 | 13篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 14篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1977年 | 3篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有576条查询结果,搜索用时 15 毫秒
91.
Aurelio Cabello-Garrido Enrique España-Ramos Ángel Blanco-López 《International Journal of Science and Mathematics Education》2018,16(7):1269-1289
This paper describes the application of the methodology developed in research on learning progressions to a health-related topic. More specifically, we present a human nutrition learning progression as a hypothesis that now requires empirical validation. The study involved three phases. In the first phase, we analysed the existing literature in the domain of human nutrition. Based on this analysis, phase 2 then involved drawing up a learning progression for this domain and identifying the learning targets and progress variables, as well as the upper and lower anchors. The analysis led us to identify five progress variables, associated with the development of the concepts of food, nutrient, energy and diet, as well as with the ability to classify foods according to their nutrients. Finally, in phase 3, we identified and described the pathways that students may follow in relation to each progress variable. Given its focus on a topic closely linked to personal health, the learning progression may be useful not only as a component of teaching modules that aim to improve scientific literacy but also as a platform for future health education campaigns that seek to promote healthy eating habits among different sectors of the population. 相似文献
92.
Manuel Toral Ibañez Margarita Caru Miguel A. Herrera Luis Gonzalez Luis M. Martin Jorge Miranda Rafael M. Navarro-Cerrillo 《Journal of Zhejiang University. Science. B》2009,10(2):112-119
A protocol of polymerase chain reaction-random amplified polymorphic DNAs (PCR-RAPDs) was established to analyse the gene
diversity and genotype identification for clones of Sequoia sempervirens (D. Don) Endl. in Chile. Ten (out of 34) clones from introduction trial located in Voipir-Villarrica, Chile, were studied.
The PCR-RAPDs technique and a modified hexadecyltrimethylammonium bromide (CTAB) protocol were used for genomic DNA extraction.
The PCR tests were carried out employing 10-mer random primers. The amplification products were detected by electrophoresis
in agarose gels. Forty nine polymorphic bands were obtained with the selected primers (BG04, BF07, BF12, BF13, and BF14) and
were ordered according to their molecular size. The genetic similarity between samples was calculated by the Jaccard index
and a dendrogram was constructed using a cluster analysis of unweighted pair group method using arithmetic averages (UPGMA).
Of the primers tested, 5 (out of 60) RAPD primers were selected for their reproducibility and high polymorphism. A total of
49 polymorphic RAPD bands were detected out of 252 bands. The genetic similarity analysis demonstrates an extensive genetic
variability between the tested clones and the dendrogram depicts the genetic relationships among the clones, suggesting a
geographic relationship. The results indicate that the RAPD markers permitted the identification of the assayed clones, although
they are derived from the same geographic origin.
Project (No. CONICYT-FONDEF PROYECT D01 I 1008) supported by the National Commission of Science and Research of Chile 相似文献
93.
ABSTRACTThis study identified clusters of adolescents who share similar cardiorespiratory fitness levels and analysed the relationships between cardiorespiratory fitness, inhibition, and math fluency in each of the clusters. The subjects were 490 high-school students aged 10–16 years. The mean age was 13.82 years (SD = 1.12). Latent class analysis identified three clusters with high, medium, and low levels of cardiorespiratory fitness. The high-fitness cluster achieved higher scores in inhibition and math fluency than the low-fitness cluster. Path analysis revealed that the influence of cardiorespiratory fitness on inhibition was non-existent in the three clusters. The effect of inhibition on math fluency was positive and significant in all three cardiorespiratory fitness levels. Cardiorespiratory fitness had a direct, positive, and significant effect on math fluency only in the high-fitness cluster. Therefore, a high level of cardiorespiratory fitness is a significant determining factor in the explanation of math fluency. These results indicate that inhibition does not mediate the relationship between cardiorespiratory fitness and math fluency. However, the benefits of cardiorespiratory fitness affect math fluency, which has important implications for the educational environment and the teaching/learning process. 相似文献
94.
Guillermo Fernández-Anaya José-Job Flores-Godoy Armando-Fabian Lugo-Peñaloza Rodrígo Muñoz-Vega 《Journal of The Franklin Institute》2013,350(10):2881-2900
This paper studies the stabilization and passification of a class of distributed-order linear time-invariant systems, by using methods of preservation in the frequency domain. Results about preservation of stability and passivity of classical linear time-invariant systems are extended to one more general family of matrix functions. Based on these results, a new approach to the problems of stabilization and passification of distributed-order linear time-invariant systems is presented. Also a result that extends the known techniques for pole placement of classical linear time-invariant systems to the new class of distributed-order linear time-invariant systems is given. Examples are given to show the validity of theoretical results. 相似文献
95.
96.
97.
98.
Montserrat Castelló Marta Pardo Anna Sala-Bubaré Núria Suñe-Soler 《Higher Education》2017,74(6):1053-1068
Despite the increasing popularity of doctoral education, many students do not complete their studies, and very little information is available about them. Understanding why some students consider that they do not want to, or cannot, continue with their studies is essential to reduce dropout rates and to improve the overall quality of doctoral programmes. This study focuses on the motives students give for considering dropping out of their doctoral degree. Participants were 724 social sciences doctoral students from 56 Spanish universities, who responded to a questionnaire containing doctoral degree conditions questions and an open-ended question on motives for dropping out. Results showed that a third of the sample, mainly the youngest, female and part time students, stated that they had intended to drop out. The most frequent motives for considering dropping out were difficulties in achieving a balance between work, personal life and doctoral studies and problems with socialization. Overall, results offer a complex picture that has implications for the design of doctoral programmes, such as the conditions and demands of part-time doctoral studies or the implementation of educational proposals that facilitate students’ academic and personal integration into the scientific community in order to prevent the development of a culture of institutional neglect. 相似文献
99.
Carmen M. Martínez-Roldán Sandra Quiñones 《Journal of Language, Identity & Education》2016,15(3):151-164
In this article, we share findings from a critical qualitative study aimed at better understanding the ways that language, history, and geography mediate our work and identities as educational researchers. As scholars whose particular sociocultural and political histories are often absent in scholarly discussions about language and education, we use the intergenerational sharing of testimonios as both methodology and narrative development to gain a deeper understanding of experiences involving the learning and use of English that influence our academic careers. We theorize our experiences as resisting erasure and contribute to Latina epistemology scholarship and critical educational research about Puerto Ricans in the United States. Moreover, we forward the concept of funds of knowledge as a professional practice. Telling our stories and developing mentoring networks is necessary for our individual and collective functioning and well-being as scholars; it cultivates solidarity as a means of thriving in the academy. 相似文献
100.
A developmental perspective on full- versus part-day kindergarten and children's academic trajectories through fifth grade 总被引:1,自引:0,他引:1
Children's kindergarten experiences are increasingly taking place in full- versus part-day programs, yet important questions remain about whether there are significant and meaningful benefits to full-day kindergarten. Using the Early Childhood Longitudinal Study's Kindergarten Cohort ( N = 13,776), this study takes a developmental approach to examining associations between kindergarten program type and academic trajectories from kindergarten (ages 4–6 years) through 5th grade (ages 9–12 years). Full-day kindergarten was associated with greater growth of reading and math skills from fall until spring of kindergarten. Initial academic benefits diminished soon after kindergarten. The fade-out of the full-day advantage is in part explained by differences in the children who attend part- and full-day kindergarten as well as school characteristics. 相似文献