sum from n=1 to n(i~ma~i)的解析求和公式

给出当m为正整数时的解析求和公式并提出了L三角形的非线性数字邻居关系,较好地揭示了其系数关系．     

Reading Arabic texts: Effects of text type,reader type and vowelization

While much is known about Latin orthography little is known about Arabic orthography. This study investigates the effect of vowels on reading accuracy in Arabic orthography. Participants were 64 native Arabic speakers. Four kinds of written Arabic texts were administered: narrative, informative, poetic and Koranic. Three texts of each kind were presented in three reading conditions: correctly vowelized, unvowelized and wrongly vowelized. Results indicated that vowels had a significant effect on reading accuracy of poor and skilled readers in reading each of the four kinds of texts. The results are discussed in light of the concept that more cross-cultural considerations should be made in reading theory today.     

Contributions to a molecular phylogeny and systematics of Anemone and related genera (Ranunculaceae-Anemoninae)

 Plastid atpB/rbcL intergenic spacer sequences were obtained from 21 selected taxa and one hybrid of Anemoninae (Anemone, Pulsatilla, Hepatica) and compared with Ficaria (Ranun- culinae) as an outgroup. From the resulting matrix (1226 bp) a single most parsimonious tree was obtained (Fig. 1 ). The branching of this tree is confirmed by many informative indels and appears largely congruent with past plastid restriction analyses. Several new taxa are added. The monophyly of the Anemoninae and their early split into two major clades is supported: clade I with the chromo- some base number x = 8, clade Ⅱ with the reduced x = 7. Clade Ⅰ is made up of the basal Pulsatilla and the Rivularis + Vitifolia groups. The Multifida group links to the crown groups Coronaria, Blanda and Nemorosa. Clade Ⅱ consists of the basal Dichotoma group, followed by Hepatica, and finally by the N. Hemisphere Narcissiflora and the S. Hemisphere Antucensis groups as sisters. The problems of the Anemoninae ancestry, phylogenetic differentiation, and recent attempts for systemat- ic classification are critically discussed. In view of the still incomplete sampling of DNA data, aconservative and informal approach to classification problems is recommended.     

一种进口胶粘剂溶剂的剖析

采用化学法和FT IR、GC/MS等现代测试技术 ,分析、测定了透明型光学用胶粘剂 (简称光学胶 )溶剂的化学结构为苯乙烯 (C6 H6 CHCH2 ) .     

The impact of student misconceptions on student persistence in a MOOC

Massive Online Open Courses (MOOCs) provide opportunities to learn a vast range of subjects. Because MOOCs are open to anyone with computer access and rarely have prerequisite requirements, the range of student backgrounds can be far more varied than in conventional classroom-based courses. Prior studies have shown that misconceptions have a huge impact on students' learning performance; however, no study has empirically examined the relationship between misconceptions and learning persistence. This study of 12,913 MOOC-takers examines how students' misconceptions about the upcoming course material affect course completion. Using a survival analysis approach, we found that, controlling for the score in a pre-course test, students holding more misconceptions had a higher dropout rate at the start of the course, an effect that diminished over time. Other student variables were found to have a positive impact on survival that persisted throughout the entire course: U.S. location, higher age, an intention to complete, better English skills, prior familiarity with the subject, motivation to earn a certificate, and score and time spent on the previous problem set (homework). By contrast, student gender, education level, number of previous MOOCs completed, and motivation to participate in online discussion forums did not affect survival.     

Teaching for social justice: A research synthesis on Asian American and Pacific Islander teachers in U.S. schools

This article examines social justice in teaching and teacher education with a focus on the experiences, pedagogies, and instructional practices of Asian American and Pacific Islander (AAPI) teachers. We synthesized 37 peer-reviewed research publications on AAPI teachers’ experiences and contributions to diversity and social justice. The results show AAPI teachers disrupting Whiteness through beliefs, pedagogies, and practices that value multiple perspectives and marginalized voices. Policy implications include supporting cultural and linguistic diversity in teacher education programs and schools and providing opportunities for teachers to engage in critical praxis regarding their racial identities and issues of equity in education.     

Game-Based Learning in Virtual Worlds: A Multiuser Online Game for Medical Undergraduate Radiology Education within Second Life

Game-based learning can have a positive impact on medical education, and virtual worlds have great potential for supporting immersive online games. It is necessary to reinforce current medical students' knowledge about radiological anatomy and radiological signs. To meet this need, the objectives of this study were: to design a competition-based game in the virtual world, Second Life and to analyze the students' perceptions of Second Life and the game, as well as to analyze the medium-term retention of knowledge and the potential impact on the final grades. Ninety out of 197 (45.6%) third-year medical students voluntarily participated in an online game based on self-guided presentations and multiple-choice tests over six 6-day stages. Participants and non-participants were invited to perform an evaluation questionnaire about the experience and a post-exposure knowledge test. Participants rated the experience with mean scores equal to or higher than 8.1 on a 10-point scale, highlighting the professor (9.5 ± 1.1; mean ± SD) and the virtual environment (8.9 ± 1.1). Participants had better results in the post-exposure test than non-participants (59.0 ± 13.5 versus 45.3 ± 11.5; P < 0.001) and a lower percentage of answers left blank (6.7 ± 8.4 versus 13.1 ± 12.9; P = 0.014). Competitive game-based learning within Second Life is an effective and well-accepted means of teaching core radiological anatomy and radiological signs content to medical students. The higher medium-term outcomes obtained by participants may indicate effective learning with the game. Additionally, valuable positive perceptions about the game, the educational contents, and the potential benefit for their education were discovered among non-participants.     

中华系列医学杂志学术质量控制机制应用现状调查

以中华医学会杂志社中华系列101种医学期刊作为调查对象,从公开编委会成员、责任编辑、利益冲突声明、作者贡献、原始数据和同行评审专家这6个方面切入,全面地了解目前这些医学期刊学术质量控制机制应用现状.     

主体的颠覆:拉康精神分析学中的"自我"

作为认识之主体的自我的身份无疑是哲学领域中的一个重大问题,但是这个问题在笛卡尔之前的本体论哲学中被视为不证自明的而放进了括号;认识论哲学将认识主体,也就是说将自我作为至关重要的问题提出来,但是最终还是将同一性和自主性赋予了它;语言论哲学的革命使人们得以重新思考这个问题,并对同一、自主的自我作了彻底的颠覆。但是,这种颠覆不是来自于形而上学,而是来自于拉康对弗罗伊德精神分析的创造性阐释。因为拉康的贡献,我们终于认识到,自我的同一和自主只是一种虚构和妄想,自我根本上是分裂的,因为自我其实就是一个他。自我的存在是为另一个人而建构的,建构的方式和结果使他像另一个人,而且其存在注定要被另一个人夺走。所以,自我的本质就是一种挫折。     

混合集成电路STR-S6708A工作原理

本文对电视机常用电源ICSTR-S6708A及开关电源工作原理进行了分析。