Electric and mechanical performances of Bi0.5Sb1.5Te3 prepared by spark plasma sintering

Thermoelectric (TE) materials are a kind of functional materials which can be used to convert directly heat energy to electricity or reversely.The thermoelectric effects hold great potential for application in power generation and refrigeration.Bi2Te3 and its alloys are well known as best TE materials currently available near room temperature.This paper studies respectively the effects of spark plasma sintering (SPS) on electric performance of Bi0.5Sb1.5Te3 thermoelectric materials that are prepared through vacuum melting and ball milling.Through X-ray Diffraction and cold field emission scanning electric microscope s4800, the phase constituent and microstructure of the TE materials samples were analyzed.Electric conductivity and power factor can be improved with the rise of Spark Plasma Sintering temperature (from 300 to 500 ℃) and pressure(from 30 to 60 MPa), and the density and mechanical strength of Bi0.5Sb1.5Te3 thermoelectric material increase, too.     

含稀土硅化铁热电材料的电学性能初探

采用悬浮真空熔炼和800℃,168h真空退火方法制备了含稀土Sm的FeSi2基金属硅化物,并对其晶体结构、See-beck系数、电阻率进行了初步研究。实验发现,名义组成为Fe0.6Sm0.4Si2的试样的热电功率因子从室温时的0.26×10-4W·m-1K-2随温度上升到500℃时的1.6×10-4W·m-1K-2,比不含Sm或含Sm量很少的对比试样高一个数量级左右。其原因被认为是由于Sm的外层4f电子的贡献。     

糠醛生产与热电联合处理糠醛废渣模式探讨

糠醛废渣问题是制约我国糠醛行业发展的瓶颈。本文运用工业协作的基本原理,对糠醛生产和热电联合处理糠醛废渣模式进行了分析探讨,对于有效解决糠醛废渣问题及糠醛行业和其它行业实践生态工业具有积极的意义。     

基于国家电网的财务管理系统的开发与研究

随着社会生产力的不断发展,越来越多的企业认识到了财务工作的重要性。企业要利用现代高效的运作方式来开发和管理组织中最重要、最昂贵的资源,实现财务管理的精细化、自动化,提高财务资源的利用率,促进企业的发展。     

Additive-aided electrochemical deposition of bismuth telluride in a basic electrolyte

A new basic electrolyte with two cationic plating additives,polydiaminourea and polyaminosulfone,was investigated for the electrochemical deposition of the bismuth telluride film on a nickel-plated copper foil.Tellurium starts to deposit at a higher potential(-0.35 V) than bismuth(-0.5 V) in this electrolyte.The tellurium-to-bismuth ratio increases while the deposition potential declines from-1 to-1.25 V, indicating a kinetically quicker bismuth deposition at higher potentials.The as-deposited film featu...     

自源无线温度检测技术的研究与应用

基于温差模块、DS18B20和红外技术的自源无线温度检测技术,利用故障发热部位与环境的温度差发电自给,解决高压现场内难以获得低压电源的问题;利用红外线传输信号,避免在高压变电站中布线和信号受高压现场的强电磁干扰.实验结果表明,半导体温差模块输出电压与温差在一定范围内呈线性关系,温差越大,输出电压越大.采用带有超低压启动器的DC/DC电压提升电路进行电压提升,解决实际应用中由于温差过小而导致的半导体温差模块输出电压过低,不足以提供所需的电压问题.     

与李代数A2相关的顶点算子代数N（k,0）及不可约模

介绍了仿射李代数A2的构造,并研究和构造了A2上Z＋-分次的顶点算子代数N（k,0）。再由A（V）理论算出了顶点算子代数L（1,0）不可约模L（1,μ）的分类情况。     

热电能源材料研究进展

在介绍热电材料的背景、发展历史、主要应用的基础上,概括了目前提高热电材料性能的方法。主要包括:通过态密度共振和能带简并来提高Seebeck系数;通过掺杂点缺陷、纳米结构和多晶晶界等方法对声子进行全方位散射来降低晶格热导率;通过基体和纳米第二相的能带对齐来维持电传输性能;使用本征低热导率材料等。最后对热电材料的研究进行了总结和展望。     

Thermoelectric properties of mechanically alloyed iron disilicides consolidated by various processes

Mn doped p-type iron disilicide powders have been produced by a mechanical alloying process. As-milled powders were of metastable state and mostly transformed to β-FeSi₂ phase by subsequent isothermal annealing. As-milled powders were consolidated by various processes such as sintering of the cold compact in vacuum, vacuum hot pressing (VHP), and spray drying/atmospheric plasma thermal spraying. Phase transitions during the processes were investigated using XRD, EDS, and SEM. As-consolidated specimens consisted of a mixture of α-Fe₂Si₅ and ε-FeSi phases, which were gradually transformed into a thermoelectric semiconducting α-FeSi₂ phase by subsequent isothermal annealing in the vicinity of 845°C in vacuum. However, some residual α and ε phases remained even after prolonged annealing. Thermoelectric properties were measured as a function of temperature and correlated with phase transformation. They showed optimum values in the vacuum hot pressed specimen due to a higher fraction of β phase and/or higher density.     

P型Sr0．5Co4-xFexSb12化合物的制备及高温热电性能

采用熔融法结合放电等离子烧结（SPS）技术合成了P型填充方钴矿化合物Sr0．5Co4-xFexSb12，并研究了Fe掺杂对该化合物高温热电性能的影响。采用X．射线衍射（XRD）及电子探针（EPMA）表征了化合物的物相及化学成分，在300～850K温度范围内测试了化合物的电导率、赛贝克系数和热导率，采用Vande Pauw方法测试了化合物的室温载流子浓度。实验结果表明，化合物的主要相组成为Sr0．5Co4-xFexSb12方钴矿相，同时含有少量FeSb2和CoSb2杂质相。化合物的赛贝克系数均为正值，表明为空穴导电。随着Fe掺杂量的增加，化合物的载流子浓度及电导率增加，赛贝克系数降低，晶格热导率降低，最小室温晶格热导率为1．97 Wm^-1K^-2。对于化合物Sr0．5Co2.32Fe1.68Sb12在850K时获得的最大热电性能指数ZT约为0．60。