Synthesis, Structure and Performance of Li-Ni-Co-Mn-O Compounds as Cathode Materials for Lithium Ion Batteries

近年来，掺杂型的层状锂锰氧化物材料已经引起了人们的广泛关注，特别是LiMn1/3Ni1/3Co1/3O2，该材料具有价格低、热稳定性好的优势，被认为是目前最有希望取代LiCoO2的候选正极材料之一。本文采用多种结构分析、表面分析、电化学研究方法和实验手段，从合成方法、结构特征、电化学性能等多方面对锂镍锰钴氧化物系列正极材料进行了系统深入的研究，制备出性能良好的锂镍锰钴氧化系列正极材料，其电化学性能达到了我们所承担国防项目的预期指标。本文的主要研究结果如下：1.采用氢氧化物共沉淀预处理高温固相烧结法合成LiNi1/3Mn1/3Co1/3O2正极材料，并对其合成条件进行了优化。首先对不同沉淀温度下...Li-Ni-Co-Mn-O compounds, especially LiMn1/3Ni1/3Co1/3O2, are promising candidates of cathode materials for lithium ion batteries because of higher capacity, lower material cost than LiCoO2 and good thermal stability. In this study, many research methods such as structure analysis, surface analysis and electrochemical tests were applied to study the synthetic methods, structure and electrochemical ...学位：理学硕士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：20032507

Genomic Insights into the Formation of Human Populations in East Asia

厦门大学人类学研究所、厦门大学生命科学学院细胞应激生物学国家重点实验室王传超教授课题组与哈佛医学院David Reich教授团队合作，联合全球43个单位的85位共同作者组成的国际合作团队通过古DNA精细解析东亚人群形成历史。研究人员利用古DNA数据检验了东亚地区农业和语言共扩散理论，综合考古学、语言学等证据，该研究系统性地重构了东亚人群的形成、迁徙和混合历史。这是目前国内开展的东亚地区最大规模的考古基因组学研究，此次所报道的东亚地区古人基因组样本量是以往国内研究机构所发表的样本量总和的两倍，改变了东亚地区尤其是中国境内考古基因组学研究长期滞后的局面。 该研究是由王传超教授团队与哈佛医学院（David Reich教授）、德国马普人类历史科学研究所（Johannes Krause教授）、复旦大学现代人类学教育部重点实验室（李辉教授和金力院士）、维也纳大学进化人类学系（Ron Pinhasi副教授）、南洋理工大学人文学院（Hui-Yuan Yeh助理教授）、俄罗斯远东联邦大学科学博物馆（Alexander N Popov研究员）、西安交通大学（张虎勤教授）、蒙古国国家博物馆研究中心、乌兰巴托国立大学考古系、华盛顿大学人类学系、台湾成功大学考古所、加州大学人类学系等全球43个单位的85位共同作者组成的国际合作团队联合完成的。厦门大学人类学研究所、厦门大学生命科学学院细胞应激生物学国家重点实验室为论文第一完成单位。厦门大学人类学研究所韦兰海副教授、胡荣助理教授、郭健新博士后、何光林博士后和杨晓敏硕士参与了研究工作。The deep population history of East Asia remains poorly understood due to a lack of ancient DNA data and sparse sampling of present-day people1,2. We report genome-wide data from 166 East Asians dating to 6000 BCE-1000 CE and 46 present-day groups. Hunter-gatherers from Japan, the Amur River Basin, and people of Neolithic and Iron Age Taiwan and the Tibetan plateau are linked by a deeply-splitting lineage likely reflecting a Late Pleistocene coastal migration. We follow Holocene expansions from four regions. First, hunter-gatherers of Mongolia and the Amur River Basin have ancestry shared by Mongolic and Tungusic language speakers but do not carry West Liao River farmer ancestry contradicting theories that their expansion spread these proto-languages. Second, Yellow River Basin farmers at ～3000 BCE likely spread Sino-Tibetan languages as their ancestry dispersed both to Tibet where it forms up ～84% to some groups and to the Central Plain where it contributed ～59-84% to Han Chinese. Third, people from Taiwan ～1300 BCE to 800 CE derived ～75% ancestry from a lineage also common in modern Austronesian, Tai-Kadai and Austroasiatic speakers likely deriving from Yangtze River Valley farmers; ancient Taiwan people also derived ～25% ancestry from a northern lineage related to but different from Yellow River farmers implying an additional north-to-south expansion. Fourth, Yamnaya Steppe pastoralist ancestry arrived in western Mongolia after ～3000 BCE but was displaced by previously established lineages even while it persisted in western China as expected if it spread the ancestor of Tocharian Indo-European languages. Two later gene flows affected western Mongolia: after ～2000 BCE migrants with Yamnaya and European farmer ancestry, and episodic impacts of later groups with ancestry from Turan.We thank David Anthony, Ofer Bar-Yosef, Katherine Brunson, Rowan Flad, Pavel Flegontov,Qiaomei Fu, Wolfgang Haak, Iosif Lazaridis, Mark Lipson, Iain Mathieson, Richard Meadow,Inigo Olalde, Nick Patterson, Pontus Skoglund, Dan Xu, and the four reviewers for valuable comments. We thank Naruya Saitou and the Asian DNA Repository Consortium for sharing genotype data from present-day Japanese groups. We thank Toyohiro Nishimoto and Takashi Fujisawa from the Rebun Town Board of Education for sharing the Funadomari Jomon samples, and Hideyo Tanaka and Watru Nagahara from the Archeological Center of Chiba City who are excavators of the Rokutsu Jomon site. The excavations at Boisman-2 site (Boisman culture), the Pospelovo-1 site (Yankovsky culture), and the Roshino-4 site (Heishui Mohe culture) were funded by the Far Eastern Federal University and the Institute of History,Archaeology and Ethnology Far Eastern Branch of the Russian Academy of Sciences; research on Pospelovo-1 is funded by RFBR project number 18-09-40101. C.C.W was funded by the Max Planck Society, the National Natural Science Foundation of China (NSFC 31801040), the Nanqiang Outstanding Young Talents Program of Xiamen University (X2123302), the Major project of National Social Science Foundation of China (20&ZD248), a European Research Council (ERC) grant to Dan Xu (ERC-2019-ADG-883700-TRAM) and Fundamental Research Funds for the Central Universities (ZK1144). O.B. and Y.B. were funded by Russian Scientific Foundation grant 17-14-01345. H.M. was supported by the grant JSPS 16H02527. M.R. and C.C.W received funding from the ERC under the European Union’s Horizon 2020 research and innovation program (grant No 646612) to M.R. The research of C.S. is supported 30 by the Calleva Foundation and the Human Origins Research Fund. H.L was funded NSFC (91731303, 31671297), B&R International Joint Laboratory of Eurasian Anthropology (18490750300). J.K. was funded by DFG grant KR 4015/1-1, the Baden Württemberg Foundation, and the Max Planck Institute. Accelerator Mass Spectrometry radiocarbon dating work was supported by the National Science Foundation (NSF) (BCS-1460369) to D.J.K. and B.J.C. D.R. was funded by NSF grant BCS-1032255, NIH (NIGMS) grant GM100233, the Paul M. Allen Frontiers Group, John Templeton Foundation grant 61220, a gift from Jean-Francois Clin, and the Howard Hughes Medical Institute. 该研究得到了国家自然科学基金“中国东南各族群的遗传混合”、国家社科基金重大项目“多学科视角下的南岛语族的起源和形成研究”、厦门大学南强青年拔尖人才支持计划A类、中央高校基本科研业务费等资助

利用ReaxFFMD方法对煤加氢热解的探索

本文用ReaxFF MD[1]方法对煤加氢热解机理进行研究。以郑默提出的柳林煤模型化合物[2]为基础,构建了常规、真空环境、加氢柳林煤体系并进行了热解模拟。分析获得了产物分布随温度演变的规律。结果显示高温下氢气的作用(阻止结焦)开始显现。本文还对甲烷生成路径进行了分析,结果显示自氢化反应生成甲烷倾向于发生在密集的惰性体系中,而加氢体系甲烷的生成主要与氢气有关。这些结论均与文献[2][3]描述一致

ReaxFF MD模拟煤热解新方法:GPU并行与化学信息学分析

本报告介绍将GPU并行与化学信息学分析相结合、利用ReaxFF MD模拟煤热解的新方法,通过建立国际上首个GPU加速的ReaxFF MD程序GMD-Reax以及国际上第一个实现对ReaxFF MD模拟轨迹进行化学反应自动分析的工具VARxMD,实现了对大规模煤模型热解的ReaxFF MD模拟

Arc error separation and compensation technology of rectangular aspheric surface

研究了砂轮圆弧半径误差对大口径矩形轴对称非球面加工的影响。采用直线光栅式平行磨削的加工方式,建立了砂轮圆弧半径的误差分离的数学模型,分析影响面形精度的因素,根据加工及测量方式将砂轮圆弧半径误差分离出来,利用分离的砂轮圆弧半径误差更新砂轮圆弧半径,同时采用分离后的误差数据进行补偿加工。实验结果表明:对比不分离的补偿加工结果,粗磨和精磨条件下的分离误差补偿加工后的面形误差分别减小了14%和35%,该误差模型能够有效地分离出砂轮圆弧半径误差,分离误差效果明显,提高了加工的精度。To study the effect of the wheel-arc error on large-scale rectangular axisymmetric aspheric machining,the grating parallel grinding method is adopted and the mathematical model of wheel-arc error separation is built.The factors that affect the surface accuracy are analyzed and it is found that the wheel-arc error is the most sensitive in the factors.According to the grinding and measurement method,the wheel-arc error is separated.Using the new wheel-arc radius modified by separated wheel-arc error and the new compensation data subtracted from wheel-arc error,the separating error compensation grinding is carried out and proves effective.The experimental results show that the aspheric surface error decreases by 14% and 35% after separating error compensation grinding in rough and fine grinding conditions.The error model can separate the wheel-arc error effectively and the accuracy of the aspheric surface is improved.国家科技重大专项项目(2011ZX04004-061); 国家自然科学基金项目(51075343

Preparation,Characterization and Electrochemical Performance of LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) as Cathode Materials in Lithium Ion Battery

以过渡金属乙酸盐和氢氧化锂为原料,应用共沉淀或流变相预处理高温烧结法优化并制备出L iN i0.4Co0.2Mn0.4O2正极材料.X射线衍射技术(XRD)及R ietveld结构精修、扫描电子显微技术(SEM)、综合热分析(TG-DSC)表征结果和电化学测试结果表明,该材料具有单一层状结构,颗粒大小均匀,热稳定性好,首次放电比容量高达208.7 mA.h/g(2.0~4.6 V,0.1 C),电化学性能优异.非原位(ex situ)XRD测定结果表明,材料充至高电位下发生的不可逆相变造成了材料的循环容量衰减.Cathode material of LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) was prepared by mixed hydroxide or rheological reaction method at 850 ℃ within 15 h.The materials were characterized by XRD with Rietveld refinement,SEM,TG-DSC and electrochemical tests.The results showed that it has R-3m layered structure,with a high capacity and good thermal property.It delivered a specific capacity as high as 208.7 mA·h/g(2.0—4.6 V,0.1 C).Phase change of Li_(x)Ni_(0.4)Co_(0.2)Mn_(0.4)O_(2)(0<x<1) in charge-discharge process will affect the cyclic stability of the materials,especially in the first 10 circles.国家自然科学基金(批准号:20473068,29985310)资

反应分子动力学(ReaxFF MD)模拟结果分析工具VARxMD

反应分子动力学(ReaxFF MD)是一种很有潜力研究较大体系(&gt;1000个原子)复杂化学反应的方法。国际上现有的ReaxFF MD模拟结果分析工具无法让用户了解所模拟的过程中发生的化学反应细节,对于规模小或简单的反应体系进行人工分析还可以接受,但对于原子规模达到~1000-~10000的大体系模拟,反应分析功能的缺乏,将使研究者对反应机理的分析陷入困境。本文研发的反应分子动力学分析与可视化工具VARxMD(Visualization and Analysis of ReaxFF Molecular Dynamics),它是国际上第一个实现对ReaxFF MD模拟轨迹进行化学反应自动分析的工具。VARxMD是基于Qt/VTK和其它第三方库研发的跨平台图形用户界面程序,借助化学信息学的化学结构处理方法,对ReaxFF MD模拟结果轨迹中的原子、物种、成断键的分析,并结合数据可视化和分子片段结构可视化,实现对ReaxFF MD模拟结果的深度分析,可获得模拟过程中完整的化学反应信息。VARxMD已应用于煤热解和聚乙烯等复杂分子体系热解的化学反应机理探索,且VARxMD具有通用性,有望被应用于更多的体系

A Novel Flexible Dye-Sensitized Solar Cell Based on Pt Networks Counter Electrode

柔性染料敏化太阳能电池(DSSCs)作为一种新型的化学太阳能电池,因其精简的封装工艺、较低廉的价格、高的化学稳定性以及可弯折等优点而备受关注.本文介绍了一种新型的柔性DSSC的制备,其光阳极为高度有序的氧化锌(Zn O)纳米线阵列,对电极为柔性、导电、透明的网状铂(Pt networks)电极.相对于传统的铂对电极而言,这种Pt networks对电极不仅具有优异的导电能力,还展现了极好的透光性(方阻~100Ω·sq-1,~80%透光率)和催化性能,此外,Pt networks电极可构筑于任意弯曲的衬底,具有优异的机械耐弯折性能.在Zn O纳米线阵列的DSSCs的应用中,基于Pt networks膜的柔性DSSC的转化效率比铂纳米丝阵列(Pt nanofiber arrays,Pt NFs)膜高出了32%.Flexible dye-sensitized solar cells(DSSCs) have received widespread attentions in recent years because of their ease of fabrication, low production cost, relatively high chemical stability and flexibility. We report the fabrication of Zn O DSSCs based on the highly flexible, conducting, catalytic and transparent Pt networks counter electrode, and the performance of this solar cell was characterized by SEM, XRD, polarized fluorescence microscope, motor, I-V test station and electrochemical workstation. Compared to Pt nanofiber arrays(NFs), Pt networks not only show a better conductivity, but also exhibit superior transparency and catalytic activity. Furthermore, Pt networks electrode could be constructed on arbitrary flexible substrates. The fabricated flexible Zn O DSSC based on Pt networks counter electrode achieved 1.33% photoelectric conversion efficiency, which is 32% higher than that based on Pt NFs.国家自然科学基金项目(No.51502253);; 中央高校基本科研业务费(No.20720150030);; 高等学校学科创新引智计划“111计划”(No.B16029)资

硝酸脱除褐煤粉煤灰中的砷

基于砷在褐煤粉煤灰中的赋存状态,建立了酸法脱除粉煤灰中部分砷的新方法,考察了反应温度、时间、pH值等对脱砷率的影响.结果表明,褐煤灰中的砷大多富集在煤灰表面并以砷酸钙等砷酸盐形式存在,脱砷率与pH值和反应温度成反比.综合考虑脱砷率、溶损率等因素,确定酸法最优脱砷条件为pH=1、反应温度20℃、反应时间1 h,此时脱砷率为66.34%