Cognitive load in algebra: element interactivity in solving equations

Central to equation solving is the maintenance of equivalence on both sides of the equation. However, when the process involves an interaction of multiple elements, solving an equation can impose a high cognitive load. The balance method requires operations on both sides of the equation, whereas the inverse method involves operations on one side only. In an experiment, middle school students (N?=?71) were randomly assigned to the balance and inverse methods to complete a pre-test, an acquisition phase and a post-test. Pre-test and post-test comparisons found that the inverse group outperformed the balance group for those equations that involved high element interactivity. Instructional efficiency measures further confirmed that the balance method imposed higher cognitive load. The inverse method was capable of reducing cognitive load due to the interacting elements.     

易经本义的现代数理新论

扇形"宇宙本体本源演绎图"是运用现代自然科学和中国古代数象原理相互观照的方法设计而出,它以0和1表达易经阴阳的两仪、四象和八卦。太极以坤为祖,将古老的八卦与现代数理链接起来。道与能是内涵与外延的关系,道能即宇宙的本体和本源。物质是不同维度的能量自组合的呈现和表达,三维在道能演化过程中是一个节点,与爱因斯坦的相对论公式和门捷列夫的元素周期表相互印证。宇宙有可能是能量子进行能聚变而诞生。能量维度理论可将中国古代的两种宇宙生成论和谐统一起来。     

基于WEBGIS的节能减排系统的架构构思

节能降耗、发展低碳经济是我国现阶段的经济发展的目标,节能降耗涉及行业众多,数据类型不一,数据维度多变化快,需要及时全面的掌握节能减排中的基础数据和过程数据,通过信息化的手段来实现节能减排工作的过程评价、动态监管和决策支持;WEB-GIS是成熟一种的技术架构,可以充分利用internet平台进行信息发布、数据共享和交流协作,是节能减排的信息化是一个重要手段;通过对节能减排所涉及的数据特点进行详细的分析,基于WEBGIS提出系统的架构的构思,并在此基础上提出了系统的功能模块的设计。     

不同性质的球体对超声波散射的有限元分析

为了探讨单个颗粒在连续介质中对超声波的散射特性,利用多物理场耦合的有限元方法,分别对浸没于盛满水的圆柱形容器中的刚性球、液体球及气泡球对超声波的散射进行了仿真实验研究。结果表明,因为有球体的存在,改变了超声波声强在空间的分布,刚性球和液体球的超声波发射面附近声强的分布出现明显相互间隔的三个较强区域,两个较弱区域;气泡球对超声波声强的散射特性大大异于刚性球和液体球,特别是气泡球内表面附近声强出现数量较刚性球和液体球高2个数量级的较强声强散射区域,空气球内沿轴线高度方向交替出现多次峰值与0值的声强。     

有氧运动强度监测指标特征分析与研究

研究了运动指标中的心率、代谢当量、主观感觉程度与运动能量消耗等指标特征,首先,从心率对运动负荷的基本应答特征、运用目标心率安排锻炼负荷强度、心率测量的特征、心率的运动强度监测等方面分析了心率指标特征;其次,阐述了代谢当量指标与主观感觉程度特征及其分级指标;再次,从气体代谢分析仪与心率测试法等方面分析了运动能量消耗测定方法;最后进行了总结与建议。     

长江流域碳排放量的测算及减排研究

鉴于长江流域环境保护在我国转型发展中的重要战略地位,为定量研究长江流域碳排放量的变化趋势,文章在齐绍州和付坤建立的测算方法基础上,建立了分行业、分省区、分时段测算长江流域的碳排放量及其增长率的测算方法。长江流域碳排放量的结构及其增长率变化趋势表明,总的碳排放量增长率正在不断下降。这是由于长江流域各省区正在大力发展交通、物流、通讯业等惠及民生的产业,政府系列政策的实施效果不断得到体现。     

不同天气条件下古尔班通古特沙漠南缘梭梭(Haloxylon ammodendron)群落能量通量日变化特征

基于2018年夏季在古尔班通古特沙漠南缘采用波文比系统实测的气象及能量资料,分析该区不同天气条件下梭梭群落能量特征及能量分配的日变化特征。结果表明：1） 该区夏季晴天和多云天各能量曲线变化趋势基本一致,呈单峰型,土壤热通量最小,晴天和多云天感热略高于潜热;阴天能量传输以感热为主;雨天整体热通量最小,且各能量曲线呈多峰形变化,能量传输以潜热为主。2） 白天,波文比值雨天最小,且小于1,晴天、多云天、阴天依次增大,且大于1;夜间,晴天、阴天、多云天、雨天的波文比值依次增大,均小于1。3） 不同天气条件下能量分配曲线白天变化平稳,夜间波动显著,日出和日落前后波动最为剧烈;因不同天气条件下辐射强度和日照时数的不同,曲线早、晚剧烈变化开始时间有所不同。     

Extraterrestrial artificial photosynthetic materials for in-situ resource utilization

Aerospace milestones in human history, including returning to the moon and manned Martian missions, have been implemented in recent years. Space exploration has become one of the global common goals, and to ensure the survival and development of human beings in the extraterrestrial extreme environment has been becoming the basic ability and technology of manned space exploration. For the purpose of fulfilling the goal of extraterrestrial survival, researchers in Nanjing University and the China Academy of Space Technology proposed extraterrestrial artificial photosynthesis (EAP) technology. By simulating the natural photosynthesis of green plants on the Earth, EAP converts CO₂/H₂O into fuel and O₂ in an in-situ, accelerated and controllable manner by using waste CO₂ in the confined space of spacecraft, or abundant CO₂ resources in extraterrestrial celestial environments, e.g. Mars. Thus, the material loading of manned spacecraft can be greatly reduced to support affordable and sustainable deep space exploration. In this paper, EAP technology is compared with existing methods of converting CO₂/H₂O into fuel and O₂ in the aerospace field, especially the Sabatier method and Bosch reduction method. The research progress of possible EAP materials for in-situ utilization of extraterrestrial resources are also discussed in depth. Finally, this review lists the challenges that the EAP process may encounter, which need to be focused on for future implementation and application. We expect to deepen the understanding of artificial photosynthetic materials and technologies, and aim to strongly support the development of manned spaceflight.     

能源经济学:新的挑战与应对之道——国际能源经济学会(IAEE)第四届亚洲大会综述

当今世界能源-环境-经济-社会可持续发展面临诸多新的变化与挑战,能源经济学作为新兴的交叉科学,可以发挥重要的基础性作用。国际能源经济学会(IAEE)第四届亚洲大会以"能源经济学:新的挑战与应对之道"为主题,在北京成功举办。文章系统总结了会议的丰硕成果和能源经济学领域的研究热点,分析了未来的学科发展趋势。