Representational Issues in Students Learning About Evaporation

This study draws on recent research on the central role of representation in learning. While there has been considerable research on students’ understanding of evaporation, the representational issues entailed in this understanding have not been investigated in depth. The study explored students’ engagement with evaporation phenomena through various representational modes. The study indicates how a focus on representation can provide fresh insights into the conceptual task involved in learning science through an investigation of students’ responses to a structured classroom sequence and subsequent interviews over a year. A case study of one child’s learning demonstrates the way conceptual advances are integrally connected with the development of representational modes. The findings suggest that teacher-mediated negotiation of representational issues as students construct different modal accounts can support enriched learning by enabling both (a) richer conceptual understanding by students, and (b) enhanced teacher insights into students’ thinking.     

基于ESI数据的高校优势学科实证分析

长三角一体化战略为长三角的"双一流"高校发展提供了重大历史机遇。本研究在"双一流"和长三角一体化背景下,对长三角8所"双一流"高校从优势学科分布与潜力学科建设进行研究。首先,采用文献计量方法,以ESI数据为基础,对8所高校的优势学科分布情况进行分析;其次,通过学科比重方法和学科潜力指标方法,并结合长三角一体化发展需求以及8所"双一流"高校学科发展需要,探讨各个高校应着力打造和重点培育的潜力学科;最后,结合8所高校已有的优势学科和需要重点发展的潜力学科提出形成系列学科集群、建立学科联盟、特色发展的建议。     

Potential production simulation and optimal nutrient management of two hybrid rice varieties in Jinhua,Zhejiang Province,China

Potential growth of two widely-grown hybrid rice varieties in the Jinhua district of Zhejiang Province, Shanyou63 for mid-rice and Xieyou46 for late rice, was simulated using a crop growth model of WOFOST. Parameters of the rice growth in WOFOST were calibrated through field experiments from 1999 to 2002 in Jinhua. The potential yield simulated with WOFOST was about 12 t/ha for Shanyou63 and 10 t/ha for Xieyou46, which are in good agreement with the highest recorded yield obtained in this area. Under farmers practice, current yield is about 7.5 t/ha for Shanyou63 and 6.5 t/ha for Xieyou46. There is a gap between the actual rice yield and the potential yield for these two hybrid rice varieties grown in this area. The attainable target yields were set to 70% to 75% of their potential yields for the two varieties. A recently developed software ＂Nutrient Decision Support System （NuDSS）＂ for irrigated rice was used to optimize nutrient management for these two rice varieties. According to NuDSS, the optimal fertilizer N requirement for the target yields was about 150 kg/ha for Shanyou63 and about 120 kg/ha for Xieyou46, which were only about 70% of the fertilizer N application under current farmers＇ practice. Comparing with farmers＇ practice, there is great potential to increase actual rice yields and to reduce fertilizer N use rates by improving rice crop management practice in Jinhua.     

以色列的中介学习经验理论及其应用

二战后,为满足以色列儿童心理成长和能力促进的实际需要,以弗厄斯坦为代表的以色列教育学家和认知心理学家提出了中介学习经验理论并将之应用于教育实践。该理论从教授者与学习者间交互作用的视角看待学习者的认知发展与学习,主张个体的认知结构是一个开放的系统,教授者在中介学习过程中可采用多种有益的中介策略指导和训练儿童,以促进他们认知能力的提高和认知结构的改善,并推动其学习潜能的实现。该理论的实践应用包括:1)构建学习潜能评估工具,用它评价个体认知能力的改变,诊断个体的认知缺陷;2)设立工具强化程序并施之于教学中以巩固儿童已改变的认知结构。中介学习经验理论对于在测评和教学中动态把握和促进巩固儿童的潜能发展具有重要意义。     

Parents’ PTSD symptoms and child abuse potential during the perinatal period: Direct associations and mediation via relationship conflict

BackgroundPosttraumatic stress disorder (PTSD) symptoms are associated with parental aggression towards children, but little is known about the relation between parents’ PTSD symptoms and their risk for perpetrating child physical abuse during the early parenting years, when the potential for prevention of abuse may be highest.ObjectiveTo examine direct associations between mothers’ and fathers’ PTSD symptoms and child abuse potential, as well as indirect effects through couple relationship adjustment (i.e., conflict and love) in a high-risk sample of parents during the perinatal period, most of whom were first-time parents.Participants and settingFrom March 2013 to August 2016, data were collected from 150 expecting or new parental dyads in which the mother was participating in a home visiting program.MethodsData were analyzed using the Actor-Partner Interdependence Mediation Model.ResultsFor mothers and fathers, there were direct associations between PTSD symptom severity and child abuse potential (βs = .51, ps <.001), and this association for fathers was stronger at higher levels of mothers’ PTSD symptoms (β = .15, p = .03). In addition, parents’ own and their partners’ PTSD symptoms were each indirectly associated with parents’ own child abuse potential through parents’ report of interparental conflict (standardized indirect effects = .052–.069, ps = .004) but not love.ConclusionsAddressing parents’ PTSD symptoms and relationship conflict during the perinatal period using both systemic and developmental perspectives may uniquely serve to decrease the risk of child physical abuse and its myriad adverse consequences.     

渭河流域潜在蒸散量时空变化及其突变特征

本文根据渭河流域21个气象站1959年-2008年的逐日气象资料,选取FAOPenman-Monteith法计算各站潜在蒸散量,然后采用Spline插值法生成流域潜在蒸散量分布图,并利用Mann-Kendall法分析各站年潜在蒸散量长期变化趋势,最后采用Pettitt法对各站年潜在蒸散量进行突变检验。结果表明:流域多年平均年潜在蒸散量在779.1～1017.6mm之间,空间分布总体趋势为东高西低,北高南低,由东北向西南递减,其中夏季>春季>秋季>冬季;近50年来流域大部分地区潜在蒸散量呈增大趋势,西安周边小部分中下游地区出现减小趋势;流域年潜在蒸散量有两个偏大期和一个偏小期,各季值与年值变化趋势大体一致,其中夏季和春季对年值贡献最大;13个站点年潜在蒸散量在0.05显著性水平上检测到突变点,15个站点年值在1993年、1994年发生明显增大突变,4个站点在1978年、1979年出现明显减小突变。     

论我国2008年奥运会潜优势项目的确定与超常规发展策略

我国奥运优势项目和潜优势项目的研究经历了概念的提出、界定标准的建立、具体项目的认定等过程,通过对2008年奥运会我国项目实力水平的评定与优势、潜优势项目的确定,提出我国奥运会潜优势项目超常规发展策略:1)提供政策保障的"环境优化策略";2)优势项目带动潜优势项目发展的"双赢策略";3)投入倾斜、重点布局的"偏食策略";4)进一步突出女子项目优势的"凤飞策略";5)打破固定程序的"催化策略";6)聚合人力资源、优选优训的"人才支前策略".     

APF方法在船舶自动避碰中的应用

提出一种改进的人工势场(Artificial Potential Field,APF)方法,将船舶的速度和操纵特性引入到模型的引力和斥力函数中,用于实现船舶自动避碰.讨论APF中的局部最小点问题,并提出解决方法.     

飘球原理归结及其潜在威力之分析

本文以排球新规则有关发球条文为依据，运用流体力学原理，根据风洞实验、自由落体实验的结论与数据，对飘球的原理及特点进行了深入的探讨分析，揭示了现阶段挖掘飘球潜在威力的可行性与现实性。