Controllable Fabrication and Their Lithium Storage and Catalytic Properties of ZnO-Based Hybrid Hollow Micro-nanostructures

过渡金属氧化物作为锂离子电池负极材料时具有比传统的石墨负极更高的理论容量和更好的安全性能，在过去的一二十年里备受研究人员的青睐。在各种过渡金属氧化物中，ZnO除了具有原料丰富、加工成本低廉、无毒性、生物兼容性好、简单易制、形貌多样等优点外，作为锂离子电池负极材料时，还能通过转移反应和合金化反应贡献出高的理论容量（978mAhg-1），这几乎是石墨负极理论容量的三倍，是一种非常有应用前景的负极材料。但是到目前为止相比于NiO、Co3O4等过渡金属氧化物，ZnO微纳米材料的锂存储性能研究较为少见。这主要是由于在充放电循环过程中ZnO材料的体积变化非常大，可达到228%以上。ZnO电极材料剧烈的体积...In the past decades, transition metal oxides have achieved enormous research interest for using as the anode materials in lithium ion batteries due to their higher theoretical capacity and safety in comparison with the conventional graphite-based anodes. In addition to the merits of rich resource, non-toxicity, low processing cost and diverse morphology, ZnO, as a fascinating member of transition ...学位：工学博士院系专业：材料学院_材料物理与化学学号：2072012015331

Project Basic research on high efficiency energy storage devices based on nanostructured materials

2016年2月国家科技部组织编制了纳米科技重点专项实施方案并发布了2016年度项目申报指南。通过形式审查、函评、视频答辩等申报环节,纳米科技重点; 专项最终在7个研究方向上启动了43个项目。针对指南中5.2纳米能量存储材料及器件,由厦门大学牵头,联合武汉理工大学、华南理工大学及中山大学,组织; 申报的高效纳米储能材料与器件的基础研究项目获得了支持。本文介绍了高效纳米储能材料与器件的基础研究项目的目的与意义,研究目标,拟解决的关键科学问题; ,研究内容与考核指标,研究团队与研究基础,研究挑战和项目预期效益。Ministry of Science and Technology of the Peoples Republic of China; organizes nano science and technology key implementation project in Feb.; 2016 and releases the annual project declaration Guide. Totally 43; projects focusing on seven different research areas are announced in; Jun. 2016. A research team led by Prof. PENG Dongliang from Xiamen; University with the project title of Basic research on high efficiency; energy storage devices based on nanostructured materials has been; funded. In this project, scientific and technological issues concerning; advanced lithium ion batteries will be studied, aiming to greatly; improve their energy density (3400 W·h/kg) and cycling stability (3500; cycles).国家重点研发计划项

Hollow micro/nanostructures metal oxide as advanced anodes for lithium-ion batteries

电动汽车和智能电网的快速发展对锂离子电池提出了更高的要求,即在拥有高能量密度和高功率密度的同时,兼有快速充放电和较高的安全性能。电极材料是电池性; 能的关键,金属氧化物因为拥有较高的比容量和安全性能,已经成为有希望替代传统商用石墨负极的新型电极材料。然而,金属氧化物负极的循环结构稳定性较差、; 电导率低,由此导致差的循环及倍率性能,极大地阻碍了其商业化应用。近年来,拥有微纳米空心结构的金属氧化物显示出了优异的电化学性能。本文介绍了制备空; 心结构金属氧化物的常用方法,讨论了各种方法的优缺点,并列举了常见空心结构金属氧化物作为锂离子电池负极时的性能表现,最后对空心结构金属氧化物未来的; 发展方向和发展前景予以展望。More efforts are needed to upgrade the performances of lithium-ion; batteries (LIBs) for their further applications in various large; electrical appliances such as electric vehicles and smart grid as these; devices require high capacity, power density, high rate capability and; especially safety. Electrode materials are the key to the performance of; LIBs. Recently, metal oxides with much higher capacities and better; safety have the prospect of becoming alternative anode materials of; commercial graphite. However, the intrinsic low charge/ionic; conductivity and poor cycling structural stability lead to poor cycling; and rate performances, which greatly hinder their commercial; applications. To overcome these disadvantages of metal oxide anodes for; LIBs, several strategies have been developed during the past decade.; Among them, metal oxide hollow micro-nanostructures exhibit excellent; electrochemical properties as anode material for LIBs. In this review,; we first describe the current commonly preparation methods to synthesize; metal oxide hollow structures and comment on their advantages and; shortages. According to some typical examples, we show the promising use; of metal oxides hollow-structured anode materials for LIBs. Finally, the; direction and prospect of metal oxide hollow micro-nanostructures using; as anode materials are further discussed.国家重点研究计划纳米科技重点专项; 国家自然科学基金; 福建省自然科学基金项目; 厦门大学校长基

富锂锰基正极材料研究进展

目前富锂锰基正极材料以其高比容量(>250mAh/g)、高工作电压、低成本、环境友好等优点受到了学术界的极大关注,是极具潜力的下一代锂离子电池正极材料。然而,循环过程中富锂锰基正极材料存在首次库仑效率低、倍率性能差、容量与电压衰减严重等缺点,使其实际应用受到了极大限制。经过几年来的深入研究,人们对富锂锰基正极材料的理论认识逐步加深,发展了针对富锂锰基正极材料各种缺点的改性方法,取得了一系列重要进展。本文总结了近几年来学术界在富锂锰基正极材料方面的重要研究进展,包括放电比容量、首次库仑效率、循环性能、倍率性能、电压稳定性,总结了针对富锂锰基正极材料的各种实验表征手段。此外,还介绍了富锂锰基正极材料在理论研究方面的重要方法以及在全电池方面的应用。最后,基于目前的实验进展和理论认知,对富锂锰基正极材料今后的发展进行了展望。国家重点研发计划“纳米科技”重点专项(2016YFA0202600

Study of Lithium Storage Properties for Yolk-shell ZnO-NiO-ZnCo_2O_4 Composite Microspheres

通过简单的液相吸附法合成夹心结构的柠檬酸锌镍钴微米球并以此为自模板在空气中煅烧制备了夹心结构的znO-nIO-znCO2O4混合微米球.通过X射线衍射(Xrd)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等研究方法对合成样品的物相、形貌、结构及成分进行了表征.用作锂离子电池负极材料时,夹心结构的znO-nIO-znCO2O4混合微米球显示出良好的锂存储性能.在100MA/g电流密度下充放电循环140次后夹心结构混合微米球的比容量达到1 194MAH/g.混合微米球优越的锂存储性能与其独特的夹心结构、小的纳米组成单元以及不同成分间的协同效应密切相关.Yolk-shell ZnO-NiO-ZnCo2O4 composite microspheres were successfully synthesized with calcination of yolk-shell zincnickel-cobalt citrate microspheres precursor in air.The precursor was pre-produced through a two-step consecutive aging process of zinc citrate solid microspheres in nickel nitrate and cobalt nitrate solution.X-ray diffraction(XRD),scanning electron microscopy(SEM)and transmission electron microscopy(TEM)were applied to characterize the morphologies,structures and compositions of the as-obtained samples.When used as the anode materials for lithium ion batteries,the harvested yolk-shell ZnO-NiO-ZnCo2O4 composite microspheres exhibited good electrochemical properties.After 140 cycles,a high specific capacity of about 1 194mAh/g could be reached at a current density of 100 mA/g.The special yolk-shell configuration,the synergetic effect between ZnO,NiO and ZnCo2O4 nanoparticles,and the nanometer-sized building blocks of composite microspheres were responsible for excellent lithium storage properties.国家重大科学研究计划项目(2012CB933103); 国家自然科学基金(51171158;51371154); 中央高校基础业务专项(201312G003

Direct Wafer Bond of GaAs/InP Materials and Devices

　采用三步法在GaAs衬底上实现InP材料的键合,通过X 射线光电子谱(XPS)对样品键合界面进行化学价态和深度分布分析。结果表明,键合温度小于450℃时,样品界面主要由三维氢键网络组成;大于450℃时界面处发生互扩散,Ⅴ族元素主要在界面处富集,而Ⅲ族元素具有较深的扩散。因此提出界面层以InGaAs、InGaP为主,这种界面化学态的变化对样品的I V特性和键合强度都具有实质意义的影响,同时由于异质结带阶的存在,要获得良好的电学性质和强度,键合温度并不是越高越好,而是存在一个最佳温度。最后,在GaAs衬底上成功地键合了InGaAs/InP光电探测器。GaAs/InP materials are successfully bonded at 350 ℃ by three-step method. The chemical states and depth profile of bonded InP/GaAs interface are analyzed by using X-ray photoelectron spectroscopy (XPS). The results show that the bonded interface is made from the networks of hydrogen when the annealing temperature below 450 ℃, but the interdiffusion at InGaAs (or/and InGaP) interface is carried out when the temperature above 450 ℃, and the I-V characteristics and bonding strengths depend strongly on the change of chemical states. To obtain excellent I-V characteristics and bonding energy, the annealing temperature should be optimized. Based on our experimental results and the discussions, the mechanism of GaAs/InP direct bonding is proposed. In the end, InGaAs/InP detectors are successfully bonded on the GaAs substrate at 450 ℃.国家自然科学基金资助项目(60006004)

5种植物对铀的积累特征差异研究

采用盆栽试验,研究不同铀浓度(0、1、5、20 mg/kg)胁迫下,苜蓿、黑麦草、高丹草、苏丹草和印度芥菜的光合色素、可溶性蛋白质和丙二醛(MDA)含量的变化,以及植物地上部分和根部对铀的富集量。结果表明,低浓度铀可刺激植物光合色素和可溶性蛋白质含量的增加,但随着铀浓度的增加,植物光合色素和可溶性蛋白质含量逐渐下降。铀胁迫诱导植物体内MDA含量呈明显升高的趋势

黑麦草对铀胁迫的生理响应及其积累特征研究

针对铀矿冶地域周边低放土壤的植物修复问题,采用盆栽试验,研究了黑麦草在不同质量比(0、1 mg/kg、5 mg/kg、20 mg/kg)铀胁迫下的生长响应、抗氧化体系酶活性的变化及对铀的积累特征。结果表明,低质量比(土壤铀质量比为1 mg/kg)铀胁迫下,黑麦草叶绿素a、叶绿素b和类胡萝卜素质量比增加,但随土壤中铀质量比增加,植物光合色素质量比逐渐下降。当土壤铀质量比为1 mg/kg时,黑麦草茎叶和根部的可溶性蛋白质质量比均较对照组略有增加,随土壤铀质量比增加,当土壤铀质量比为5 mg/kg和20 mg/kg时,黑麦草茎叶和根部的可溶性蛋白质质量比均呈降低趋势,且均低于对照组。铀胁迫诱导植物体内丙二醛(MDA)质量比呈明显升高的趋势。当土壤铀质量比低于5 mg/kg时,铀胁迫茎叶和根部的抗氧化体系酶(过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT))活性提高,当土壤铀质量比为20 mg/kg时,黑麦草茎叶和根部的POD、SOD、CAT活性大幅降低。黑麦草对铀的富集量随铀质量比增加而增加,土壤铀质量比为20 mg/kg时,黑麦草对铀的生物富集量达到最大值,其中,地上部铀质量比为70.94 mg/kg,根部铀质量比为338.37 mg/kg。铀质量比在黑麦草体内分布为地上部小于根部

哈密地区冰川变化趋势分析/Change Trend of Glaciers in the Hami Region[J]

雪冰融水是哈密地区地表径流的一种主要方式.受全球气候变暖的影响,哈密地区的冰川处于加速融化的阶段,水资源成为哈密地区发展的主要瓶颈.通过对哈密地区冰川物质平衡、面积、厚度、冰川区水文气象等参数的观测,预测冰川水文和水资源的变化,为更好地利用好哈密地区有限的水资源,为可持续发展,提出应对措施