全文获取类型
收费全文 | 10072篇 |
免费 | 103篇 |
国内免费 | 11篇 |
专业分类
教育 | 6963篇 |
科学研究 | 1185篇 |
各国文化 | 72篇 |
体育 | 754篇 |
综合类 | 3篇 |
文化理论 | 66篇 |
信息传播 | 1143篇 |
出版年
2022年 | 64篇 |
2021年 | 117篇 |
2020年 | 170篇 |
2019年 | 233篇 |
2018年 | 362篇 |
2017年 | 357篇 |
2016年 | 328篇 |
2015年 | 212篇 |
2014年 | 309篇 |
2013年 | 1742篇 |
2012年 | 251篇 |
2011年 | 286篇 |
2010年 | 239篇 |
2009年 | 223篇 |
2008年 | 264篇 |
2007年 | 223篇 |
2006年 | 199篇 |
2005年 | 180篇 |
2004年 | 197篇 |
2003年 | 138篇 |
2002年 | 162篇 |
2001年 | 212篇 |
2000年 | 227篇 |
1999年 | 194篇 |
1998年 | 110篇 |
1997年 | 149篇 |
1996年 | 129篇 |
1995年 | 98篇 |
1994年 | 119篇 |
1993年 | 85篇 |
1992年 | 174篇 |
1991年 | 134篇 |
1990年 | 131篇 |
1989年 | 158篇 |
1988年 | 140篇 |
1987年 | 108篇 |
1986年 | 122篇 |
1985年 | 117篇 |
1984年 | 90篇 |
1983年 | 104篇 |
1982年 | 68篇 |
1981年 | 83篇 |
1980年 | 73篇 |
1979年 | 113篇 |
1978年 | 77篇 |
1977年 | 67篇 |
1976年 | 61篇 |
1975年 | 58篇 |
1974年 | 66篇 |
1973年 | 63篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
We report a new Cretaceous multituberculate mammal with 3D auditory bones preserved. Along with other fossil and extant mammals, the unequivocal auditory bones display features potentially representing ancestral phenotypes of the mammalian middle ear. These phenotypes show that the ectotympanic and the malleus-incus complex changed notably during their retreating from the dentary at various evolutionary stages and suggest convergent evolution of some features to extant mammals. In contrast, the incudomalleolar joint was conservative in having a braced hinge configuration, which narrows the morphological gap between the quadroarticular jaw joint of non-mammalian cynodonts and the incudomalleolar articulations of extant mammals. The saddle-shaped and abutting malleus-incus complexes in therians and monotremes, respectively, could have evolved from the braced hinge joint independently. The evolutionary changes recorded in the Mesozoic mammals are largely consistent with the middle ear morphogenesis during the ontogeny of extant mammals, supporting the relation between evolution and development. 相似文献
82.
83.
This study was designed to obtain the perceptions of regular class teachers who taught children who had been in EMR programs, but had been decertified (D) and returned to regular classes in response to court cases and recent legislation. A cohort of regular class (RC) students were selected for comparative purposes. It was found that D students were placed into low ability classes; yet, teachers perceived D subjects to be significantly lower than RC students in both academic achievement and social acceptance. Only a small proportion of teachers indicated that the enrollment of D students had much impact on the regular class instructional program. However, the teachers were rather critical of the services received under the auspices of a transitional program, indicating in large part that the services were either not apparent or ineffective. 相似文献
84.
Behavior modification research in the classroom was examined by the National Commission for the Protection of Human Subjects because of the increasingly widespread use of behavioral procedures in the schools, the effectiveness of these procedures in changing academic and social behavior, and the consequent concern about potential misuse. In order to foster the responsible use of behavior modification procedures in the schools on a practical as well as a research basis, the following ethical issues being considered by researchers and the involved public are discussed: informed consent, determination of classroom goals, legitimacy of rewards and aversive controls in the classroom, conceptions of behavior modification as manipulative and mechanistic, who can implement the procedures, research design, and accountability. The authors conclude that the issues regarding protection of human subjects in behavior modification research are no different from other treatment-oriented research with children. However, the high degree of parental and teacher involvement in both research and practice requires shared responsibility for the prevention of misuse of behavior modification procedures. 相似文献
85.
86.
It was the purpose of this investigation to examine the effects of living with a male or female head-of-household upon the arithmetic performance of fourth graders. No significant differences were found in mean scores between male and female pupils. Significant differences were found favoring those pupils living with male heads-of-households, particularly for female pupils and for pupils with IQ scores greater than 100. These findings should not be considered as simple cause and effect relationships, but rather as indicative of potential difficulty for some pupils. 相似文献
87.
88.
89.
ABSTRACTDue to budget constraints, schools in the United States have increasingly turned to community arts organizations for support. School-community arts partnership stakeholders collaborate because of shared missions to provide students with valuable arts learning experiences. Investigations of these initiatives indicate that these partnerships improve arts learning opportunities and increase public support and resources for arts education. However, not much is known about the experiences and perspectives of the arts organizations that participate in these partnerships. Coordinating collective efforts with a multitude of institutions and interests poses challenges. In this study, we examine survey data collected from arts organization administrators who participated in a large-scale school-community arts partnership initiative. We find that these organizations are generally positive about their impacts on students’ educational outcomes, but there is substantial variation in these views. We also find that organizations differ in their levels of support for these collective efforts. Sources of this variation appear to be attributable to organizations’ preexisting resources and extent to which they are established. While this difference in levels of support is potentially inevitable, we find evidence that the operations handled by the “backbone” organization, i.e. the initiative’s facilitators and overseers, can significantly influence organizations’ levels of support for these efforts. Organizations are more likely to support these collaborative efforts when they believe the backbone organization ensures transparency with initiative operations, provides regular, effective communication, and effectively resolves competing priorities. 相似文献
90.