基于云平台的数字资源开发与应用研究——以我校《汽车电气设备构造与维修》课程为例

"加快构建以学习者为中心的教学和学习方式,依托信息技术营造信息化教学环境,促进教学理念、教学模式和教学内容改革"是《教育信息化"十三五"规划》中提出的明确要求。本文以《汽车电气设备构造与维修》课程的信息化教学改革为例,总结了适合汽车维修专业的数字资源的设计与开发模式,以及将数字资源融入在线学习的实践研究。     

Institutional and Conceptual Barriers to Climate Change Adaptation for Coastal Cultural Heritage

Climate change is increasing the speed at which tangible coastal cultural heritage is changing in character or being lost through weathering, erosion, and inundation. Damages to coastal archeological sites, loss of access to historical sites, and the alteration of cultural landscapes will force changes in the way researchers can study sites, tourists can enjoy places, and descendant communities who have lived in particular areas for time immemorial, and local community members can utilize and relate to landscapes. In the USA, the National Park Service is a primary coastal cultural resource management organization. The National Park Service has been working on climate change adaptation for cultural resources for over a decade; however, there are few examples of parks in which long range climate change adaptation plans for cultural resources have been implemented. Building from 20 semi-structured interviews with cultural resource managers in three parks, we found that institutional structures within the National Park Service, as well as historical conceptual framings specific to the research, recreational, and interpretive values of cultural resources act as barriers to managers’ ability to design and implement climate change adaptation plans. Institutional barriers managers discussed include the dependence of climate change adaptation decisions partnership projects and the leveraging of budgetary and staff resources within NPS that may affect climate change adaptation capacity. We found that park managers often saw impacts in parks that may be associated with climate change, but found it difficult to separate normal maintenance from climate change affected deterioration, which may lead to status quo management actions rather than revised planning for a changing future regime. Conceptual barriers managers discussed revealed a conflict between preservation needs of research versus interpretive uses and while NPS guidance recommends prioritization of cultural resources for preservation at the park level, regional managers were more focused on this topic than park managers. As NPS moves forward with climate change adaptation planning, opportunities to develop and improve cultural resource preservation with new technologies, improved prioritization schemes, and include public input in resource preservation may help coastal managers overcome these barriers.     

热养护下矿物掺合料高性能混凝土强度损失和孔结构研究

为了研究热养护对矿物掺合料高性能混凝土后期强度及微观结构的影响,不同恒温时长,不同恒温温度养护下矿物掺合料高性能混凝土进行强度试验和孔结构分析。结果表明：与标对准养护相比,热养护能快速提升混凝土早期强度,但热养温度越高热养时间越长混凝土后期的强度损伤越大,孔隙率也越大。80℃热养48h后转标养28d的强度损失为50℃的4.4倍,总孔隙率为1.091倍。与标准养护和自然养护相比,后养护方式采用Ca(OH)2饱和水溶液养护,对热养混凝土的后期强度和孔径分布有一定的改善。     

二代稳性衡准纯稳性丧失直接评估方法研究(二)

针对国际海事组织(IMO)正在制定的船舶第二代完整稳性衡准中的纯稳性丧失直接评估衡准,本文提出了纵荡-横荡-横摇-首摇4自由度运动耦合的标准数学模型,进行了纯稳性丧失直接评估.该方法首先基于MMG操纵性标准方法,构建纵荡-横荡-横摇-首摇4自由度运动方程,同时考虑了舵控制方程,其次在纵荡、横荡、横摇、首摇方程右边考虑时域波浪力/力矩,且横摇方程右边进一步考虑了粘性横摇阻尼力矩和波浪中复原力臂变化.最后采用ONR内倾船进行了尾斜浪中纯稳性丧失直接数值计算,为纯稳性丧失直接稳性评估衡准的应用奠定了基础.     

半潜式钻井平台暖通空调系统防寒改造研究

文章对某半潜式钻井平台中的暖通空调系统防寒改造项目进行研究,阐述了该系统防寒评估和研究方法,对寒冷工况的热损失进行计算,并提出了系统改造方案,为相关改造工程提供了参考。     

防止电机反馈试验失控的调节方法及参数设计

根据电压和功率平衡的关系分析了牵引电动机反馈试验中的电流或电压失控现象,发现失控的原因是各电机磁场特性的差异所致,得到了不出现失控的磁场限制条件,提出采用调磁的方法来消除失控现象。对调磁装置及其技术参数进行了设计,使之能满足所有试验的调节要求。     

基于资源优化的枢纽机场中转仿真

机场资源的有限性是限制枢纽机场发展的最重要因素之一,如何能够提高中转资源的利用率已经成为改善枢纽机场中转运行效率的关键性问题.采用离散事件仿真技术根据中转航班旅客到达人数的变化实时分配中转资源,并使用SIMIO仿真软件实现了上海浦东国际机场的中转运行情况,以基于资源优化的思想,为每个航班动态指派中转资源.优化结果表明,实时分配的机场资源提高了中转资源的利用率.     

我国增值税的税收流失问题研究

不同税种的税收流失对源配置的影响程度和影响途径都是不同的,在所有的税种中,以商品税的逃税对市场资源配置的扭曲最为严重,针对我国的具体情况而言,其中尤以增值税的流失影响最大。因此,在我国目前的条件下,要减少税收流失对财政收入、资源配置、宏观调控等国民经济方面造成的危害,关键是要减少增值税的流失。增值税流失的原因主要包括正式制度供给不足和缺乏非正式制度的约束以及税收的实现机制不健全三大方面;政策措施应当包括:进一步完善相关的法制法规、建立现代税收管理体制和建设良好的社会环境三个方面。     

湖南省水资源承载力分析

采用动力学模型对湖南省未来20年各行各业的需水量进行预测,并从人口和经济承载力两个方面对湖南省水资源承载能力进行分析和评价．分析结果表明,湖南省水资源可承载能力并不理想,水资源承载能力不足以维持经济和社会的稳定发展．针对分析结果提出了提高湖南省水资源可承载能力的措施．     

电动汽车低压蓄电池自充电策略优化

电动汽车的电气架构通常包括动力电池、整车控制器VCU、蓄电池、DC/DC转换器、高压箱PDU、电池管理系统BMS、充电系统以及高压附件等,在电动汽车未启动或长期放置时,作为其内部的低压用电设备,如收音机、点烟器、仪表灯光系统、整车控制器、BMS等工作电源,对于电动汽车的正常起动起着至关重要的作用。但是,在实际使用过程中,偶尔会因蓄电池亏电,导致整车无法上高压。本文阐述一种在各种工况下的技术控制策略,避免因蓄电池亏电而导致车辆无法起动,保证车辆使用的有效性。