Facile Fabrication of Fe_3O_4@TiO_2@C Yolk–Shell Spheres as Anode Material for Lithium Ion Batteries

Transition metal oxides have been actively exploited for application in lithium ion batteries due to their facile synthesis,high specific capacity,and environmental-friendly.In this paper,Fe_3O_4@TiO_2@C yolk-shell(Y-S) spheres,used as anode material for lithium ion batteries,were successfully fabricated by Stober method.XRD patterns reveal that Fe_3O_4@TiO_2@C Y-S spheres possess a good crystallinity.But the diffraction peaks' intensity of Fe_3O_4 crystals in the composites is much weaker than that of bare Fe_3O_4 spheres,indicating that the outer anatase TiO_2@C layer can cover up the diffraction peaks of inner Fe_3O_4 spheres.The yolk-shell structure of Fe_3O_4@TiO_2@C spheres is further characterized by TEM,HAADFSTEM,and EDS mapping.The yolk-shell structure is good for improving the cycling stability of the inner Fe_3O_4 spheres during lithium ions insertion-extraction processes.When tested at 200 mA/g,the Fe_3O_4@TiO_2@C Y-S spheres can provide a stable discharge capacity of 450 mAh/g over 100 cycles,which is much better than that of bare Fe_3O_4 spheres and TiO_2@C spheres.Furthermore,cyclic voltammetry curves show that the composites have a good cycling stability compared to bare Fe_3O_4 spheres.     

幼儿科学问题解决能力的发展特点与家长教育卷入的影响

为揭示幼儿科学问题解决能力的一般发展特点及家长教育卷入的影响,本研究运用幼儿科学问题解决能力测验与家长教育卷入问卷,对福建省5所幼儿园294名幼儿及其家长进行调查。结果表明,大班幼儿的科学问题解决能力总体高于中班幼儿,男生的科学问题解决能力总体高于女生;在难度较大的任务中,大班幼儿的表现显著优于中班幼儿,在难度较小的任务中,男生的表现显著优于女生;男生和女生的科学问题解决能力在4~4.5岁阶段均平稳缓慢发展;男生的科学问题解决能力在4.5~5.5岁阶段提升较为迅速;女生的科学问题解决能力在5~6岁阶段提升较为迅速。幼儿科学问题解决能力与家长教育卷入总分以及家长讨论、家长语言认知活动参与、家长生活指导等维度得分呈显著正相关。家长语言认知活动参与、家长生活指导对幼儿科学问题解决能力具有正向预测作用。家长应关注幼儿科学问题解决能力发展的年龄特点与性别差异,加强与幼儿的语言互动,培养幼儿生活自理能力,创设具有挑战性的科学探索环境,激发幼儿科学探索兴趣,以促进幼儿科学问题解决能力的发展。     

Late Development of Early Visual Perception: No Topology-Priority in Peripheral Vision Until Age 10

Topological property (TP) is a basic geometric attribute of objects, which is preserved over continuous and one-to-one transformations and considered to be processed in early vision. This study investigated the global TP perception of 773 children aged 6–14, as compared to 179 adults. The results revealed that adults and children aged 10 or over show a TP priority trend in both central and peripheral vision, that is, less time is required to discriminate TP differences than non-TP differences. Children aged 6–8 show a TP priority trend for central stimuli, but not in their peripheral vision. The TP priority effect in peripheral vision does not emerge until age ˜10 years, and the development of central and peripheral vision seems to be different.     

转型期民办学校质量评价

文章从我国民办教育发展的现状入手,分析我国民办学校在转型期发展阶段的特征表现,提出了转型期中民办学校办学质量该如何评价的问题;并从教学质量、生活管理、学校特色、家校关系、品牌影响五个方面进行评价和分析,为民办学校的内涵发展提供借鉴意义.     

A charging management-based intelligent control strategy for extended-range electric vehicles

To fully take advantage of external charging conditions and reduce fuel consumption for extended-range electric vehicles, a charging management-based intelligent control strategy is proposed. The intelligent control strategy is applied to different driving patterns based on the various characteristics of urban roads. When the vehicle is driving on arterial roads, a constant power control strategy is applied. When the driver decides to go to a charging station, the extender-off time can be determined based on the current state of the vehicle and the distance to the charging station. When the vehicle is driving on an expressway, a power follower control strategy is applied. The range-extender engine is controlled to work over a wide variety of regions to obtain optimum fuel economy. The simulation results indicate that as the vehicle arrives at the charging station, the proposed charging management-based intelligent control strategy has made the state of charge reach the lowest permissible level after the driver made the decision to charge at the charging station. Therefore, the driver can charge the vehicle with as much clean electric energy as possible from the charging station.     

在普通生物学教学中对大学生进行素质教育的探索与实践

以普通生物学教学改革为依托 ,尝试从学科的内涵和概念的拓展入手 ,针对教学方法、教学内容进行改革 ,对学生专业知识体系的构架、科学思维能力和实验动手能力的培养、生物学思想建立等综合素质的培养进行全方位的探索 ,以期为高校素质教育的研究提供思路     

H.26 L帧内预测编码的研究与实现

介绍H.26L压缩编码标准和基于4×4子块的TML-9预测编码测试模型，写出实现算法，并用Visual C＋＋编程实现。     

递延收款方式下销售商品收入的确认与会计核算

新《企业会计准则》对递延方式分期收款销售商品业务的处理与原办法相比已产生了实质性的变化,由此对企业利润、现金流产生一定的影响。为了规范企业递延方式分期收款销售商品收入的会计核算,真实完整地提供会计信息,防范经营风险,本文结合新准则分析了递延方式分期收款销售商品收入的确认条件及会计处理要点。     

概念整合对幽默言语的阐释力

本文从认知的角度,利用概念整合网络及图表形式清晰地将幽默效果的获取这一动态的过程呈现出来,一方面丰富了国内关于幽默言语的研究,有助于人们对幽默言语的欣赏,另一方面也有助于人们对概念整合相对于概念隐喻理论的优势的了解。     

远程开放教育教学资源建设问题研究

本章从现代远程开放教育的教学规律入手，讨论了在远程教育实施过程中，远程教学工作如何以提供高质量的教学资源作为支持，来满足远程教育学习学习需要的问题。作从教学过程的实际出发，对现代远程开放教育中教学资源建设存在的问题进行讨论，同时对资源建设特色不明显、实用性不够强、适应性偏差、更新慢而不能激发学生兴趣，整合不够规范等主要问题进行了归纳、分析和总结，最后根据教学实践和教学检查中的调查研究情况，并结合学生反馈的意见提出了电大系统教学资源建设应该发挥系统优势、体现特色、提高质量、注重实用、规范整合的基本思路。