全文获取类型
收费全文 | 22917篇 |
免费 | 361篇 |
国内免费 | 15篇 |
专业分类
教育 | 16348篇 |
科学研究 | 2032篇 |
各国文化 | 218篇 |
体育 | 1903篇 |
综合类 | 13篇 |
文化理论 | 175篇 |
信息传播 | 2604篇 |
出版年
2022年 | 180篇 |
2021年 | 261篇 |
2020年 | 382篇 |
2019年 | 602篇 |
2018年 | 827篇 |
2017年 | 800篇 |
2016年 | 700篇 |
2015年 | 420篇 |
2014年 | 658篇 |
2013年 | 4429篇 |
2012年 | 636篇 |
2011年 | 646篇 |
2010年 | 469篇 |
2009年 | 484篇 |
2008年 | 539篇 |
2007年 | 480篇 |
2006年 | 426篇 |
2005年 | 408篇 |
2004年 | 367篇 |
2003年 | 356篇 |
2002年 | 341篇 |
2001年 | 475篇 |
2000年 | 393篇 |
1999年 | 359篇 |
1998年 | 203篇 |
1997年 | 210篇 |
1996年 | 240篇 |
1995年 | 235篇 |
1994年 | 181篇 |
1993年 | 200篇 |
1992年 | 321篇 |
1991年 | 298篇 |
1990年 | 298篇 |
1989年 | 298篇 |
1988年 | 255篇 |
1987年 | 301篇 |
1986年 | 265篇 |
1985年 | 304篇 |
1984年 | 246篇 |
1983年 | 211篇 |
1982年 | 190篇 |
1981年 | 163篇 |
1980年 | 153篇 |
1979年 | 258篇 |
1978年 | 182篇 |
1977年 | 168篇 |
1976年 | 153篇 |
1975年 | 141篇 |
1974年 | 148篇 |
1971年 | 140篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
OBJECTIVE: There were two aims: First, to compare children's rates of being battered in home, by peers, and by teachers among students between China and Korea, and second, to identify particular risk factors for such violence. METHODS: Children in grades four through six in Shanghai (238 cases) and Yanji (245 cases) in China and Seoul (248 cases) and Kimpo (241 cases) in Korea were surveyed by questionnaire method. They were asked to complete the Straus' Conflict Tactics Scale and their frequencies in the three situations respectively, and other demographic items. RESULTS: Family violence during the last 1 year was experienced in 70.6% (minor 42.2%; serious 22.6%) of the children in China and 68.9% (minor 9.4%; serious 51.3%) of those in Korea. Experience rates of violence by peers were 42.7% (minor 25.7%; serious 13.7%) in China and 26.0% (minor 11.5%; serious 14.3%) in Korea. Finally, rates of corporal punishment by teachers were 51.1% (minor 28.0%; serious 4.1%) in China and 62.0% (minor 8.8%; serious 43.8%) in Korea. The most important and common risk factor for violence in one situation was the presence of violence in another situation. CONCLUSIONS: The findings indicate that the differences in children's overall experience rates were not particularly striking. However, Korean children experienced more severe forms of violence from family members and from teachers. Findings of risk factors clearly imply that there are children vulnerable to violence from multiple sources. 相似文献
992.
Educational game designers and educators are using digital games as a platform for teaching academic content, including multicultural curriculum. However, it is unclear how well digital game-based learning can coexist with the goals of multicultural education for the purpose of meeting the needs of African American children. In this essay, we raise serious questions about the use of digital games to teach about social oppression in ways that privilege the psychological well-being of African American children. We argue that digital games that intend to recreate histories of racial oppression can be harmful to African American children if they reproduce popular and problematic notions of indigenous lives and experiences. We illuminate some of the dangers of such digital games through a preliminary exploration of one digital game designed to teach about facets of African American enslavement. Our essay concludes with recommendations for culturally relevant digital game-based learning design and instruction. 相似文献
993.
Rats were exposed to two compound solutions, saline-lemon and sucrose-lemon. In Group ALT, trials with one solution alternated
with trials with the other. Group BLK received all trials with one solution before any trials with the other. Previous retardation
tests had implied that only alternating exposure would establish sucrose as an inhibitor of saline. To provide a complementary
summation test for this inhibition, in Experiment 1, all the animals received pairings of peppermint and saline and were tested
for consumption of peppermint-sucrose under sodium depletion. Consumption was increased by sodium depletion only in Group
BLK. In Experiment 2, a retardation test was used to show that presentation of saline-lemon before sucrose-lemon on each exposure
day would establish sucrose as an inhibitor of saline. Neither exposure to sucrose-lemon before saline-lemon nor alternating
exposure to sucrose and saline alone had the same effect. These results provide support for an associative theory of perceptual
learning that suggests that exposure to complex stimuli aids later discrimination partially as a result of establishing inhibitory
associations between their unique elements. 相似文献
994.
Julia D. Plummer Valerie M. Zahm Rebecca Rice 《Journal of Science Teacher Education》2010,21(4):471-493
This study investigated the impact of an open inquiry experience on elementary science methods students’ understanding of
celestial motion as well as the methods developed by students to answer their own research questions. Pre/post interviews
and assessments were used to measure change in participants’ understanding (N = 18). A qualitative approach was used to describe the nature of each participant’s investigation through an analysis of
their science journal and poster presentations. A comparison of participants’ inquiry projects with the change in their understanding
revealed that while most participants improved in both their area of inquiry and beyond, elementary science methods students
may need more guidance to reach a full scientific understanding across all aspects of celestial motion. 相似文献
995.
996.
Xiao-Ling Jin Zhongyun Zhou Matthew K.O. Lee Christy M.K. Cheung 《International Journal of Information Management》2013
This study theorized and validated a model of knowledge sharing continuance in a special type of online community, the online question answering (Q&A) community, in which knowledge exchange is reflected mainly by asking and answering specific questions. We created a model that integrated knowledge sharing factors and knowledge self-efficacy into the expectation confirmation theory. The hypotheses derived from this model were empirically validated using an online survey conducted among users of a famous online Q&A community in China, “Yahoo! Answers China”. The results suggested that users’ intention to continue sharing knowledge (i.e., answering questions) was directly influenced by users’ ex-post feelings as consisting of two dimensions: satisfaction, and knowledge self-efficacy. Based on the obtained results, we also found that knowledge self-efficacy and confirmation mediated the relationship between benefits and satisfaction. 相似文献
997.
Evaluation of college and university teaching is considered in the context of growing demands for accountability of educational institutions and particular roles of faculty in achieving goals for which these institutions are believed to be accountable. In the first of two papers,* three contemporary aprroaches to evaluation of teaching in higher education are critically reviewed. All three of these approaches-assessment of learning outcomes, assessment of teacher characteristics and analysis of pedagogical behaviors-are found to be defective on logical, theoretical and empirical grounds. A common thread of deficiency is the absence of a coherent theoretical framework for analysis of teaching and phenomena associated with teaching. Specific defecs are analyzed in each of the three approaches as well as in the ubiquitous methodology of rating of teaching performance. In analysis of evaluation by assessment of learning outcomes, teaching is shown to be neither necessary nor sufficient to subsequent learning outcomes. Assessment of teacher characteristics fails to identify those characteristics peculiarly indigenous to teaching as a generic activity. Analysis of pedagogical behaviors fails to distinguish critical teaching acts from more general teacher characteristics interpretable in terms of teacher personality. Furthermore, no adequate basis is provided for normative interpretation of data pertaining to pedagogical behaviors. The use of rating scales to provide data about teacher characteristics or pedagogical behavior rests on assumed rather than demonstrated validity of results. Evidence of validity or meaningfulness is replaced by evidence of consistency which is often spurious. The first paper concludes with an outline of requirements for a more constructive approach to the task of teacher evaluation. In a second paper, an outline of a theory of teaching is sketched which conforms to these requirements. Realization of this theoretical structure in teaching assessment report forms is described. Tentative conclusions from trial use of forms-in-development and recommendations for additional data sources are discussed in terms of their potential contribution to improvement in teaching. 相似文献
998.
Data were collected from 289 undergraduate college students at a minority‐serving institution to explore the impact of academic rational beliefs on grit and resilience. Findings from hierarchical regression analyses suggested that academic rational beliefs related to evaluation and work habits accounted for a significant amount of variance in grit. Work habits explained a significant portion of the variance in resilience. On the basis of these results, recommendations for future research and implications for college counselors are offered. 相似文献
999.
Stephen A. Stumpf Richard D. Freedman Kenneth M. Krieger 《Research in higher education》1979,11(1):13-22
The Course-Faculty Instrument (CFI) demonstrates similar measurement properties with student populations at four diverse institutions. These students agree about the nature and extent to which course and instructor attributes relate to their learning. The results suggest that: (1) a perceived learning criterion may have general relevance to students, and (2) validity extension research is an economically feasible alternative to full-scale instrument development and validation efforts. Since validity extension is practical and facilitates cross-institutional comparisons, it appears to be a more viable strategy for researching and instituting student evaluation systems than is suggested by its current usage. 相似文献
1000.
The primary objective for modeling of machining processes is to develop a predictive capability of machining performance in order to facilitate effective planning of machining operations. This capability leads to faster implementation, higher performance, quality at a lower cost. This comes about due to improved selection of machining parameters, optimal fixture design and the avoidance of tool failure. The simulation system presented simultaneously considers the effect of cutter geometry, the cutter's initial position errors, workpiece geometry, machine tool dynamics, and workpiece/fixture system dynamics on the machining process.The integration of all of the above in one model provides an off-line tool to simulate and optimize the machining parameters and the fixture configuration cutting both lead and production time. The modular nature of the simulation system presented allows for the study of many different machining processes. The cutting forces in this system are modeled using a mechanistic approach. NURBS curves and surfaces are utilized for the geometric modeling and simulation of the machining process. While a finite element method is used to model and analyze the workpiece/fixture dynamics. Two case studies are presented to demonstrate the practical application of the presented simulation. The first case presents the optimization of the fixture configuration of a generic automotive component. While the second case presents the results of simulations performed on a novel mill/grind machining process. This process is a combination of face milling and grinding in one operation. Some simulated results are presented along with experimental validation. 相似文献