论大食与唐宋的商贸交往及其兴盛原因

阿巴斯王朝存在的500多年间商贸繁荣,它与唐宋两朝存在着转运贸易和朝贡贸易。贸易的路径有5条,主要贸易城市为广州、交州、泉州、扬州、长安、洛阳;贸易的商品种类丰富,有中国的丝绸、瓷器、铁器、漆器、农产品和中亚西亚的毛织品、玻璃、宝石、香料、药材和化妆品等;贸易规模宏大。大食与唐宋商贸兴盛的原因有三：一是大食国特殊的地理位置,二是伊斯兰教对商业贸易的鼓励,三是唐宋时开放的对外政策。     

Stereotypes and teacher characteristics as an explanation for the class-specific disciplinary practices of pre-service teachers

This paper explores the importance of class-related stereotypes for the discipline practice of pre-service teachers and whether stereotypes and discipline practice are related to their students' outward appearance. Pre-service teachers were asked to assign adjectives to photographs of children from the lower and middle social classes and to choose disciplinary actions for photographs of disruptive situations involving children from these classes. Results show that 40% of pre-service teachers treated children unfairly based on class affiliation, of these 50% punished lower-class children more harshly. The unfair treatment of lower-class children was linked to class-related stereotypes and to indicators of social identity.     

复杂应力条件下土与结构物相互作用接触面的力学特性

为研究外加荷载对接触面力学特性的影响,通过土与结构物相互作用的物理试验和数值模拟研究接触面最大剪应力的变化规律,运用PFC2D模拟土与结构物相互作用过程中颗粒位移和颗粒接触力的不同响应.结果表明:当法向应力一定时,最大剪应力随围压的增大而近似线性增大;当平均应力一定时,最大剪应力随法向应力的增大而近似线性增大;当法向应力一定、围压逐渐增加时,颗粒位移和颗粒接触力的分布与法向应力与围压的比值有关.     

Improving Educational Outcomes for Latinos: A Study of the Interactive Policy Effects of Representative Bureaucracy and Personnel Stability

This article seeks to determine whether 2 common management strategies, representative bureaucracy and personnel stability, can be used in combination with each other in order to improve educational policy outcomes for Latinos. Using data from Texas school districts from 1994 to 2010 and a cross-sectional longitudinal research design, I find that although each theory on its own improved outcomes for Latinos, the 2 did not have a significant combined effect. Instead I find evidence of a substitution effect that allows 1 strategy to be used in place of the other in order to improve the academic performance of Latinos.     

从语言接触看佛缘词对汉语词汇的影响

外来词是一种重要的社会语言现象。佛缘外来词与汉语的语言接触对汉语最直接、最明显的影响莫过于对其的借用与吸收。外来词的使用丰富了汉语语言的各个方面﹐使汉语表述更加简洁、完善;同时,也对汉语词汇产生了一定的影响。本文从语言接触的角度﹐分析了佛缘外来词产生的原因以及对汉语词汇的影响。     

钢轨波磨处高速轮轨滚动接触行为与波磨发展的模拟研究

研究目的：为求解钢轨（短波）波磨处的高速轮轨瞬态滚动接触建立有限元模型,研究影响高速钢轨波磨发展的重要因素。削新要点：1．求解不同牵引条件下轮轨间的瞬态法和切向滚动接触问题,并考虑真实轮轨几何和钢轨波磨,最高模拟速度达500km／h;2．基于模拟结果,解释了中国高速线路上发现的钢轨波磨很快稳定下来的现象。研究方法：1．详细分析钢轨波磨处高速轮轨瞬态滚动接触的法、切向解以及由此导致的V-M等效应力和摩擦功沿轨面的波动;2．变化波磨波长、波深及重要滚动参数如速度和牵引系数等,研究它们对波磨处滚动接触行为的影响;3．对比上述有限元模型与传统多体动力模型在波磨处的法向轮轨力结果。重要结论：1．法、切向轮轨力及法、切向接触应力均随着波磨几何呈周期性波动,但相位略有差异,V-M等效应力和摩擦功的波动形式接近切向接触应力;2．牵引系数越大,波磨处V-M等效应力和摩擦功的波动范围越大;3．名义参数下,对于所研究高铁系统,波长为80mm左右、速度为250-300km／h时波磨的动态响应最大,这与现场观测相符;4．传统多体动力模型会高估钢轨波磨激励的法向轮轨力;5．钢轨波磨会逐渐稳定下来,通过速度越高进入稳定越快。     

宋代的日月食起讫算法

梳理了宋代历法中的日月食起讫算法。详细分析《纪元历》《崇天历》《乾元历》日食泛用分和定用分算法,进而分析中国古代历法中处理时间和距离换算问题的两种不同思路。指出《崇天历》以前的历法使用线性插值算法处理日月食初亏到食甚的时间,《崇天历》以后的历法则采用二次内插法来处理;《纪元历》及其以后的历法为了简化运算,在对食延进行月亮不均匀性修正的过程中使用了近似算法。文中对《纪元历》的月食时差算法进行了讨论。,     

字母词的现状及未来--基于第5版和第6版《现代汉语词典》的比较研究

作为一部规范性汉语词典,《现代汉语词典》对字母词的收录反映了字母词在汉语中的存在现状。以美国语言学者托马森的语言接触理论为基础,采用统计分析的方法,对第5版和第6版《现代汉语词典》收录的字母词进行比较研究后发现,汉语受字母词的影响以英语为主,字母词的汉化程度较低,字母词的使用范围趋向日常化。同时,作为一种语言接触性演变,字母词的存在具有一定的合理性;字母词的未来发展受到语言接触强度和语言使用者态度的影响。     

万安方言中的“阿”字疑问句

万安县城话中“阿”字疑问句是一种比较特殊的问句形式,包括“阿P”、“阿是P”、“阿能P”三种类型.“阿P”问句一般用于未然时体,提问者持中立态度,“阿”字用于提示疑问焦点.“阿是P”问句用于未然或已然时体,提问者有主观预设.“阿能P”问句用于已然时体.“阿”字疑问句和县境内客家话的“格”字疑问句用法一致,表明县城赣方言受到客家话影响较大.     

How to guide learners' processing of multimedia lessons with pedagogical agents

Two experiments examined the effects of a pedagogical agent's (PA's) pointing gestures, eye gaze, and eye contact on learning processes (measured by learners' eye fixations on relevant elements) and learning outcomes (as measured by retention and transfer test scores) with a multimedia lesson on neural transmission. In Experiment 1, having the PA look at and point to relevant elements as she lectured led to more eye fixations on the relevant portion of the graphic and better retention and transfer test scores. Keeping eye contact with learners tended to improve retention test scores and increased their eye fixations on relevant elements when the PA also looked at and pointed to the graphic. In Experiment 2, the PA's pointing gestures as a stand-alone feature caused better retention test scores and more fixations on relevant elements of the graphic, but eye gaze direction did not. These findings help extend the embodiment principle.