基于“小桥理论”的变压器油击穿防止措施研究

根据变压器油的自身特征及其在换流变运行过程中表现出来的应用特点,运用"小桥理论"对变压器油的击穿过程进行分析,指出变压器油击穿的原因和影响其绝缘性能的因素,提出防止变压器油出现击穿现象的措施和方法。     

单流环密封瓦磨损产生的影响及修复

2009年1月,惠来靖海电厂#1发电机是东方汽轮机有限公司制造的QFSN-655-2-22A型,氢气纯度越来越难以维持,排补氢量较大;密封油主油泵压力低,联起直流备用油泵,无法单泵运行。分析认为是密封瓦间隙过大所引起的,最后决定利用检修的时机,采用机加工的方法修复密封瓦。检修工作取得了预期的效果,机组启动后密封瓦工作正常。     

中石化原油进口成本降低途径分析

随着我国石油企业进口原油需求量的大幅度增加,国际石油市场油价的不断变动,进口原油的各种影响因素给国内原油需求及石化企业带来了巨大的影响。如何加强对进口原油的成本控制、节省资源、优化成本构成,已成为许多石油企业面临的重大问题。结合中国石化集团进口石油的采购成本近几年持续增高的现状,对影响其价格变化的因素进行分析,指出其降低成本的途径,以期达到控制进口原油成本,规避市场风险,增加企业效益的目的。     

股权结构与公司绩效的相关性研究——以我国A股石油类上市公司为例

我们探讨石油类上市公司的股权结构、经营绩效以及两者之间的相关性,发现对于石油类上市公司而言,前5大股东为指标表示的股权集中度与公司绩效相关性并不显著;在有国家股的石油类上市公司中,国有股、公司法人股与公司绩效正相关,且效果显著;而无国家股的石油类上市公司中,国有股显然与公司绩效不相关。提出了联系实际,建立适合本行业、本企业发展的股权结构及审慎实施国有股“减持“等优化石油类上市公司股权结构,提高其经营绩效的政策建议。     

杜仲籽中油和杜仲胶的提取工艺研究

为获得长丝杜仲胶,直接以杜仲整籽为原料,对杜仲籽不经粉碎处理。用0.5%氢氧化钠于70℃除去存在于杜仲籽表面的阻挡纤维素酶作用的角质层,然后纤维素酶在pH为4、温度为45℃时破坏籽中的纤维素细胞壁,以提高细胞的通透性,然后先在常温下用石油醚提取杜仲籽油,剩余物质再用石油醚（60~90℃）于80~85℃水浴回流提取杜仲胶,得到了优质长丝杜仲胶。同时,与直接粉碎杜仲籽再用石油醚提取两物质相比,该法油脂得率提高了23%,杜仲胶得率提高了58%。     

基于广义自回归条件异方差模型的世界原油运价风险分析

为有效评估世界原油运价风险,根据世界原油运输市场运费收益的基本特性,选用基于广义误差分布(Generalized Error Distribution,GED)的广义自回归条件异方差(Generalized Auto-Regressive Conditional Heteroskedasticity,GARCH)模型,...     

突发公共卫生事件下法医临床学线上教学模式的探索与实践

受新冠肺炎疫情影响,学生不能按时返校上课,各高校积极开展线上教学活动。该文针对法医临床学课程的线上教学内容、教学方案和线上实施过程进行阐述,主要从法医临床学线上教学平台的选择、线上教学实施、考核评价、课程思政等方面开展探索和实践,最后提出今后线上教学及线上线下教学的研究方向。     

混合学习视角下MOOC的创新研究：SPOC案例分析

MOOC是近两年教育技术领域涌现的发展最快的技术之一。随着国内外一流大学的加入,基于混合学习的MOOC创新应用研究正在萌芽,并形成了基于混合学习的SPOC应用案例。该文在对混合学习及MOOC发展现状阐述的基础上,对典型SPOC案例进行分析。从学习需求、学习计划和测量策略、学习内容准备和实施和测量结果四个方面剖析,加深对案例中蕴藏的教学设计理念的理解,并为SPOC的广泛应用奠定基础。     

Modelling blended solutions for higher education: teaching,learning, and assessment in the network and mobile technology era

The article addresses the role of network and mobile technologies in enhancing blended solutions with a view to (a) enriching the teaching/learning processes, (b) exploiting the opportunities it offers for their observability, and hence for their monitoring and formative/summative assessment. It will also discuss how such potential can only be captured by solidly integrating the process of instructional design with that of monitoring and assessment. First, the article presents the proposed conception of blended solutions, giving examples. In the second part, the article discusses a possible breakdown of blended solutions into its various components and how these can enrich both the teaching/learning and the assessment processes. Finally, it addresses the question of how to combine and/or use singly the various components of blended solutions. To conclude, implications for the implementation of blended solutions are discussed, also in relation to emerging contexts such as Massive Online Open Courses (MOOCs).     

Action learning on the edge: contributing to a master's programme in Human Resources for Health

This account of practice describes the introduction of an accredited postgraduate management qualification which used action learning as a major contribution to a blended learning approach in a fragile cross-border setting on the edge of Europe. Conventional management education has frequently been challenged on the grounds of relevance, efficacy and value. In this case, action learning was combined with other blended learning approaches over a two-year period resulting in both excellent academic performance and student satisfaction results. Student completion and progression rates were exceptional and returns to the programme sponsors and the employing organisations were high. Programme participants gained an academic qualification and through action learning also gained added value through their own personal development; became more capable as independent learners and experienced enhanced social capital within their professional community.