首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   225篇
  免费   1篇
教育   140篇
科学研究   41篇
各国文化   1篇
体育   29篇
文化理论   5篇
信息传播   10篇
  2022年   2篇
  2021年   5篇
  2020年   5篇
  2019年   10篇
  2018年   18篇
  2017年   11篇
  2016年   9篇
  2015年   11篇
  2014年   10篇
  2013年   42篇
  2012年   9篇
  2011年   11篇
  2010年   4篇
  2009年   5篇
  2008年   7篇
  2007年   6篇
  2006年   3篇
  2005年   4篇
  2004年   3篇
  2003年   7篇
  2002年   3篇
  2000年   2篇
  1998年   2篇
  1997年   1篇
  1996年   4篇
  1994年   4篇
  1993年   1篇
  1992年   2篇
  1991年   2篇
  1990年   1篇
  1988年   2篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   3篇
  1981年   1篇
  1980年   1篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
  1972年   1篇
  1971年   2篇
  1961年   1篇
排序方式: 共有226条查询结果,搜索用时 609 毫秒
61.
Retroactive cue interference refers to situations in which a target cue X is paired with an outcome in phase 1 and a nontarget cue Z is paired with the same outcome in phase 2, with less subsequent responding to X being seen as a result of the phase 2 training. Two conditioned suppression experiments with rats were conducted to determine whether retroactive cue interference is similarly modulated by a manipulation that influences retroactive outcome interference (e.g., extinction). Both experiments used an ABC renewal-like design in which phase 1 training, phase 2 training, and testing each occurred in different contexts. Experiment 1 found that training the target association in multiple contexts without altering the number of training trials during phase 1 decreased retroactive cue interference (i.e., increased responding consistent with the target association). Experiment 2 found that training the interfering association in multiple contexts without altering the number of interference trials during phase 2 increased retroactive cue interference (i.e., decreased responding consistent with the target association). The possibility of similar mechanisms underlying cue interference and outcome interference is discussed.  相似文献   
62.
In many countries around the world, there has been an increasing emphasis on improving science education. Recent reform efforts in the USA call for teachers to integrate scientific and engineering practices into science teaching; for example, science teachers are asked to provide learning experiences for students that apply crosscutting concepts (e.g., patterns, scale) and increase understanding of disciplinary core ideas (e.g., physical science, earth science). Engineering practices and engineering design are essential elements of this new vision of science teaching and learning. This paper presents a research study that evaluates the effects of an engineering design-based science curriculum on student learning and attitudes. Three middle school life science teachers and 275 seventh grade students participated in the study. Content assessments and attitude surveys were administered before and after the implementation of the curriculum unit. Statewide mathematics test proficiency scores were included in the data analysis as well. Results provide evidence of the positive effects of implementing the engineering design-based science unit on student attitudes and learning.  相似文献   
63.
This study describes and analyses the conceptions of primary teachers and secondary teachers of Physics–Chemistry, Biology–Geology and Geography–History with respect to the concept of heritage and its teaching and learning, taking the model of teacher-researcher as the theoretical referent. The data collection instrument used was a questionnaire, designed on the basis of categories that in turn were used for the analysis of the resulting data. The results show a high degree of homogeneity in pedagogic content knowledge, in contrast to the heterogeneity of the conceptions with respect to purely content knowledge.  相似文献   
64.
QuickChange mutagenesis is the method of choice for site-directed mutagenesis (SDM) of target sequences in a plasmid. It can be applied successfully to small plasmids (up to 10 kb). However, this method cannot efficiently mutate bigger plasmids. Using KOD Hot Start polymerase in combination with high performance liquid chromatography (HPLC) purified primers, we were able to achieve SDM in big plasmids (up to 16 kb) involving not only a single base change but also multiple base changes. Moreover, only six polymerase chain reaction (PCR) cycles and 0.5 μl of polymerase (instead of 18 PCR cycles and 1.0 μl of enzyme in the standard protocol) were sufficient for the reaction.  相似文献   
65.
This article investigates legal and political issues as they relate to school vouchers serving students of color. Specifically, we draw on the empirical, historical, and legal research to examine whether school vouchers will create a more equitable system of education for poor students of color. First, we present a history of vouchers, including how they were used to support segregation. We then discuss how vouchers as a broad opportunity for educational equity for poor children (of color) might present particular challenges in light of, first, the race-neutral approach in contemporary case law and state statutes and, second, the relatively small percentage of U.S. children taking advantage of such programs. Finally, we present empirical results regarding African American families’ support and use of vouchers and a discussion of the racial politics of school vouchers. We argue that unless voucher programs and proponents address race directly, operate on a larger scale, and attend to the broader social justice issues facing urban communities, it will be difficult for such policies to support the greater good for African American children or society as a whole.  相似文献   
66.
The phenomenon of women engaging in entrepreneurship is expanding and becoming acknowledged as a valuable resource that must be institutionally and socially supported. Through entrepreneurship education, female students, as potential entrepreneurs, can develop and strengthen those skills and behaviours identified as characteristic of successful entrepreneurs. This paper explores four attributes associated with entrepreneurship (creativity, problem management, risk management, and self-confidence) of 1838 undergraduate students from 11 universities in Latin America (Mexico, Argentina, Brazil, Chile, Colombia, Costa Rica, El Salvador, Guatemala, and Uruguay) and one in Spain, used as a control group. By comparing the results for the male and female student population, self-confidence appears as an attribute that is present at the same level in both groups; statistically significant differences were reported for the other three attributes (creativity, problem management, and risk management). Entrepreneurship programmes can utilise such information to strengthen in female students those attributes for successful engagement in entrepreneurial activity.  相似文献   
67.
Book reviews     
Roger  Kerstin  D'Souza  Mario O. 《Interchange》1994,25(2):229-236
  相似文献   
68.
This qualitative study highlighted student perspectives on barriers to success at a community college located in a south Texas city. The study examined barriers to student success, the knowledge that successful students possess to overcome the barriers, and the actions that successful students undertake to overcome the barriers. Padilla's (2004 Padilla , R. V. ( 1999 ). College student retention: Focus on success . Journal of College Student Retention , 1 ( 2 ), 131145 .[Crossref] [Google Scholar]) theoretical framework and methods for modeling student success provided the conceptual framework for the study. The data analysis resulted in the development of a local student success model and an implementation model for student services at the subject campus.  相似文献   
69.
Abstract

Drug abuse by adolescents has been investigated in various surveys that reported correlations between age, gender, and activity. However, none of these studies included chemical analyses to help substantiate the statements of participants. In the present study, the urine specimens of 964 students (439 females, 525 males; mean age 22.1 years, s = 1.7), who applied to study sports sciences at university, were assessed for anabolic steroids, stimulants, and selected drugs prohibited in sports. In total, 11.2% of the urine specimens provided contained drugs covered by doping controls. The most frequently detected compound was the major metabolite of tetrahydrocannabinol (9.8%) followed by various stimulants related to amphetamine and cocaine (1.0%). Indications of anabolic steroid use were found in 0.4% of urine samples but originated from contraceptives containing norethisterone. The present study provided unambiguous data on the status quo of drug (ab)use by adolescents hoping for a career related to elite sport or sports sciences. No use of anabolic steroids was detected. However, evidence for stimulants and tetrahydrocannabinol administration was obtained, although not reported by any participant, which highlights the issue of under-reporting in surveys based solely on questionnaires.  相似文献   
70.
In a context of morphological expansion of the general population, how do athletes follow such a pattern of anthropometric growth? Is there any relation to performance? Biometric data including mass, height, body mass index (BMI) and age were collected for 50,376 American athletes representing 249,336 annual performers playing in professional baseball, football, ice hockey and basketball. Distributions by mass in National Football League (NFL) players are described by periods. Field goals have been studied in relation to players’ height in the National Basketball Association (NBA). Between 1871 and 2011, athletes from the four sports have increased significantly in mass, height and BMI, following a multi-exponential function series. Consequently, biometric differences between athletes and the general population are increasing gradually. Changes in the mass distribution within the NFL show the emergence of a biometrical specificity in relation to the field position. At the professional level, performance remains structured around precise biometric values. In the NBA, a height-attractor at 201.3 ± 6.3 cm for the best scorers is invariant, regardless of the level of play. These results suggest that laws of growth and biometrics drive high-level sport and organise performance around the specific constraint of each field position. Discrepancies between some mass and height developments question the (disproportionate) large mass increase (relative to the height increase) during the 1980s and 1990s.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号