Heterogeneity in the educational impacts of natural disasters: Evidence from Hurricane Florence

In September 2018, Hurricane Florence caused widespread and extended school closures throughout North Carolina. Leveraging variation within schools over time, we explore heterogeneity in the impact of hurricane-related schooling disruption on students’ end-of-grade test scores. Impacts were not concentrated on students performing at the lowest levels in the prior year nor on those from the most disadvantaged backgrounds. Rather, the estimates suggest that most students experienced small declines in test performance irrespective of baseline human capital or demographic group.     

The effect of goal-setting prompts in a blended learning environment—evidence from a field experiment

Previous literature has shown that task-based goal-setting and distributed learning is beneficial to university-level course performance. We investigate the effects of making these insights salient to students by sending out goal-setting prompts in a blended learning environment with bi-weekly quizzes. The randomized field experiment in a large mandatory economics course shows promising results: the treated students outperform the control group. They are 18.8% (0.20 SD) more likely to pass the exam and earn 6.7% (0.19 SD) more points on the exam. While we cannot causally disentangle the effects of goal-setting from the prompt sent, we observe that treated students use the online learning platform earlier in the semester and attempt more online exercises compared to the control group. The heterogeneity analysis suggests that higher treatment effects are associated with low performance at the beginning of the course.     

论我国农业科技成果转化的影响因素

农业科技成果的转化已成为我国农业发展的重要影响因素,总体来说,我国农业科技成果的转化率偏低,这已成为各界关注的重要问题。本文分析并总结了影响我国农业科技成果转化因素的相关文献,并着重探讨了我国农民的技术吸收能力和农民的信息获取等因素对农业科技成果转化的影响。     

浅谈《江西科技志》资料长篇的资料收集

科技志是专门记载科技发展历史和现状的书籍。我省新一轮的修志工作已经开始,在修志过程中,编写资料长篇的意义非常重要,本文针对《江西科技志》的资料收集方法进行了总结。关键词:科技志;志书编纂;资料长篇;收集方法     

Natural surface design for sliding mode control with multiple discontinuous inputs

It is well known that sliding mode control is based on the definition of an invariant manifold, where the system dynamics are forced to in a finite time. Such a manifold is somewhat arbitrarily defined, as long as the system dynamics are stable on it. Computational and control effort may vary depending on selected manifold. Obviously, if a system has naturally acceptable stable dynamics around a desired equilibrium point, no control is needed unless uncertainties or disturbances are present. It would be desirable that if such a system had uncertainties or disturbances, the control effort be designed only to overcome the effect of such factors. For a system with first order dynamics and affine control input, designing a sliding mode control overcoming only such uncertainties or disturbances is a trivial task. When a higher order dynamics system is involved, unit control may be used, where the input control signals are not discontinuous, but when only discontinuous control inputs are available, a design approach is not readily available. In this paper, taking advantage of the natural stable dynamics of a system, a sliding mode control approach is introduced for designing multiple discontinuous control inputs, where the control effort overcomes only uncertainties, disturbances or unstable dynamics. Two illustrative examples are given in order to show the feasibility of the method.     

“三期”叠加背景下区域发展对科技创新效能响应的SD情景仿真*

首先对2011年全国科技创新效能进行了评估,得出虽然作为我国科技大省之一的陕西省的科技资源投入相比不小,但其科技创新效能相比全国其他省区并没有太大优势,分析其原因在于科技成果转化率不高所致;进而通过系统动力学建模原理,构建陕西经济发展的SD模型,并设定三种不同的科技成果转化率情景方案,并对选取的观测变量进行仿真,得出未来陕西省科技成果转化率需要至少提升至25%以上方能实现陕西“十二五”规划中部分约束性目标;并就如何提升陕西科技成果转化效率提出建立以政府需求和市场需求相结合的研发模式、构建产学研用协同创新的产业化研发平台、建设科技创新企业混合产权制度和完善公平的市场竞争环境三项对策建议。     

四川省地震灾区婴幼儿营养监测状况分析

作者通过对四川省青川县和彭州市两个地震灾区6-24个月龄婴幼儿健康状况的统计分析,发现该地区生长发育状况不佳,存在营养不良现象,其中贫血率较高。经过对比进行营养包6个月干预后的人群统计分析,发现营养状况稍得到改善,其中彭州市目标人群贫血改善明显,由此提出面对四川其它或其它类似贫困地震地区,由于贫困,天灾必然加剧受灾人群的营养状况,特别是贫血率状况,针对这些地区的求援,必须紧迫加强营养包的干预,而且需要持续性的干预,比较可靠的预算应该在灾难期6个月以上方有一定的作用,同时必要的管理措施有利于保证营养干预对象的稳定性,提高营养干预的有效性的。     

图书版本学及其应用

介绍了版本学的概念、研究对象及范围、与相关学科关系。阐述了图书版本学是一门求知致用之学,常运用于古籍文献整理,随着时代发展,也可运用于当代图书与电子图书中。分析了版本学在图书馆的古籍图书、现当代图书和电子图书的版本整理中的应用。     

基于图书馆学五定律的高校图书馆读者借阅权限设置合理性分析

对当前高校图书馆读者借阅权限设置的现状进行了概括总结,认为目前按读者类型分别设置借阅权限、借阅权限设置粗糙且长期固化、特殊文献只限于读者阅览或特定读者使用、读者超越借阅权限需承担一定后果等做法缺乏科学性.以图书馆学五定律理论为基础,对读者借阅权限的合理设置提出一些参考性建议.     

计算机专业多课程交叉教学研究--以《数据库》课程为例

计算机专业课程众多,且课程之间联系紧密,知识内容具有交叉性,而传统的“孤立式”教学方式未注重课程之间知识的联系,不利于学生对知识体系的系统性把握,且各门课程知识点的重叠性在一定程度上加重了学生的负担。以《数据库》课程为例,提出交叉知识点融合教学、多课程捆绑式教学、交叉综合实训课程和面向应用型人才培养目标的多课程体系群四种多课程交叉教学模式,构建多层次的多课程交叉教学模式,以促进应用型计算机专业人才的培养。