覆Co(Ⅱ)-Ni/Al(OH)x的制备、结构与电化学性能

采用化学沉淀法制备了覆Co(Ⅱ)-Ni/Al(OH)x电极材料,并用XRD、SEM和粒度分布仪研究了材料的晶体结构、表观形貌和粒度分布,以恒流充放电实验测试了以其为正极活性物质组装的MH/Ni试验电池的充放电性能.结果表明:覆Co(Ⅱ)-Ni/Al(OH)x样品具有α-Ni(OH)2型晶体结构,采用覆Co(Ⅱ)-Ni/Al(OH)x电极材料制备的MH/Ni试验电池的最高放电比容量为424.53 mAh/g,600次循环后的放电比容量(395.24 mAh/g)仍为其最高放电比容量的93.1%.     

覆钴型氢氧化镍的结构及电化学性能

采用化学沉淀法制备了不同覆钴量的铝掺杂氢氧化镍[覆Co(Ⅱ)-Ni/Al(OH)x]电极材料,并用X射线衍射光谱法(XRD)和粒度分布仪表征了其晶体结构和粒度分布,用恒流充放电实验测试了以其为正极活性物质组装成MH-Ni试验电池的充放电性能.结果表明:覆Co(Ⅱ)-Ni/Al(OH)x样品具有α-Ni(OH)2型的晶体结构,覆钻量为2%～5%的Ni/Al(OH),具有最佳的充放电性能和较高的放电容量保持率.     

正极材料α-Ni(OH)2的研究进展

α-Ni(OH)2与球形β-Ni(OH)2相比,具有电化学容量高、活性物质利用率高、循环可逆性好、可使活性物质中的Ni含量降低约30%等优点,具有环境、经济和社会意义.采用掺杂技术制备出的双氢氧化合物(LDH)具有与α-Ni(OH)2相同的结构和特性,并且稳定性好,可作为电极材料使用.综述了国内外近年来LDH的制备方法、结构及性能方面的研究进展.     

Al掺杂量对纳米Ni(OH)_2结构及电化学性能影响

采用微乳液法制备Al掺杂纳米Ni(OH)2粉体,并对其结构及电化学性能进行X射线衍射光谱法(XRD)、透射电子显微镜法(TEM)、选区电子衍射(SAED)、合金表面元素组成分布(EDAX)分析及充放电性能测试。研究结果表明:随着Al掺杂含量的提高,纳米Ni(OH)2粉体由β-Ni(OH)2逐步转变为α-Ni(OH)2,其形貌由细针状逐渐转变为球形颗粒后向不规则块片状转变。随着Al含量增加,样品的放电比容量先下降后上升再下降。当Al含量为15%时,所制备的粉体为球形纳米α-Ni(OH)2,其放电比容量高达302.25 mAh/g,且放电平台高,充电电压较低。     

掺杂金属离子的氢氧化镍的电化学性能

通过共沉淀结合水热处理法,合成了不同金属离子(Ar+、Zn2+)掺杂的正极材料氢氧化镍[Ni(OH)2].用XRD测试分析样品的结构,用恒流充放电、循环伏安及交流阻抗等测试研究样品的电化学性能.单独掺杂Zn2+,得到以β-Ni(OH)2结构为主的电极材料;单独掺杂Al3+或共同掺杂Ar+和Zn2,可以获得α-Ni(OH)2的结构.共同掺杂Al3+和Zn2+的Ni(OH)2,循环稳定性好,单个镍原子交换的电子数多,最大为1.93个,且电荷转移和质子扩散阻力小.     

锌镍电池及其α-Ni(OH)_2正极材料的研究

综述了化学均相沉淀法合成α-Ni(OH)_2的方法,在适宜的温度、p H值、镍盐浓度及添加相关的活性剂下能够得到容量高、电压大、循环性能好的α-Ni(OH)_2材料。另外,通过掺杂不同的金属盐来改变其性能,并添加Zn盐、Al盐、Mn盐、铁盐、稀土金属盐等化合物,改良α-Ni(OH)_2结构。其中掺杂Al盐得到的α-Ni(OH)_2性能最好。综述了化学沉淀法以外的一些其它合成α-Ni(OH)_2的方法。     

MH-Ni电池用b-Ni(OH)_2的表征和综合评价

介绍了表征MH-Ni电池用β-Ni(OH)2的X射线衍射(XRD)方法。利用这些方法测试和分析不同来源的β-Ni(OH)2样品。结果表明:不同制备方法和不同工艺所得β-Ni(OH)2的晶粒形状、大小和层错几率明显不同;初始β-Ni(OH)2的微结构参数与充放电性能有一定的对应关系;初始β-Ni(OH)2的微结构参数在充放电过程以及循环过程都发生变化,这种变化的进程还受充放电条件和循环条件的影响。阐明了综合评价β-Ni(OH)2的必要性和重要性,最后提出综合评价β-Ni(OH)2的宏观参数和微观参数。     

镁掺杂羟基氧化镍的制备、结构和电化学性能

首次以掺杂Mg的β-Ni(OH)2为前驱体,采用K2S2O8为氧化剂,制备出/β-羟基氧化镍镁,并应用×射线衍射光谱法(XRD)、傅里叶变换红外光谱法(FTIR)、热重-差热分析(TG-DTG)、CV和放电测试对样品的结构和电化学性能进行了表征.     

MH-Ni电池用β-Ni(OH)2的表征和综合评价

介绍了表征MH-Ni电池用β-Ni(OH)2的X射线衍射(XRD)方法.利用这些方法测试和分析不同来源的β-Ni(OH)2样品.结果表明:不同制备方法和不同工艺所得β-Ni(OH)2的晶粒形状、大小和层错几率明显不同;初始β-Ni(OH)2的微结构参数与充放电性能有一定的对应关系;初始β-Ni(OH)2的微结构参数在充放电过程以及循环过程都发生变化,这种变化的进程还受充放电条件和循环条件的影响.阐明了综合评价β-Ni(OH)2的必要性和重要性,最后提出综合评价β-Ni(OH)2的宏观参数和微观参数.     

覆钴Ni(OH)2电极在充放电循环过程中的结构变化

β-Ni(OH)2在高倍率充电或过充电时容易转化为γ-NiOOH,引起电极膨胀、变形,从而影响电池的性能和寿命.在β-Ni(OH)2微粒表面化学覆钴后能改善电极的性能,通过X射线衍射(XRD)研究发现,化学覆钴后的β-Ni(OH)2电极在充放电循环过程中其γ-NiOOH的产生能得到明显抑制;扫描电子显微镜(SEM)测试发现充放电循环后β-Ni(OH)2微粒的粉化明显减少.     

Users' Needs Lighting, Start-Up Power, Transportation, Mechanical Utilities, Heating, Refrigeration, and Production

The needs for emergency and standby power to enhance industrial and commercial power systems are frequently left wanting due to ignorance of the needs or of the systems available to satisfy the needs. This paper discusses various situations which require or desire emergency or standby power and mentions suitable systems for each application. The areas discussed include lighting, start-up power, transportation, mechanical utilities, heating, refrigeration, and production.     

Grades, Quizzes, Motivation, and Computers

The following paper describes the use of a simple FORTRAN computer program that may be used to determine course grades. The program is based on processing a set of IBM punched data cards. Each card contains the name of a student and all of his grades, including the final examination grade. The program may also be used to predict the final examination grade, based on previous quiz grades, and then, in turn, to predict the final course grade. It is thus possible to use this program periodically throughout the entire semester in order to provide the student, as well as the instructor, with a measure of his progress.     

光、城市、生活、未来……——世博轴及地下综合体工程艺术灯光景观

工程介绍 世博轴及地下综合体工程（简称世博轴）位于浦东世博园核心区。南起耀华路,跨雪野路、南环路、北环路、及浦明路,到滨江世博公园。     

Dual-rotor, radial-flux, toroidally wound, permanent-magnet machines

A novel machine family-dual-rotor, radial-flux, toroidally wound, permanent-magnet (RFTPM) machines-is proposed in order to substantially improve machine torque density and efficiency. After the principles of operation, configurations, and features are discussed, the machine design and optimization guidelines are given. A prototype has been designed, built, and tested. The measured torque density of the prototype, which well matches the design value, is almost three times of that of the induction machine with the same power of 3 hp and speed. Meanwhile the efficiency is still kept high and the material cost is kept low by using ferrite magnets. Three novel approaches are proposed to reduce the cogging torque in the RFTPM machines, whose validity is verified by finite-element analysis results and experimental measurements.     

A new soft-switched, thyristor-based, regenerative, quasi-resonant,current regulated inverter

A variety of soft-switching techniques have been proposed to reduce the switching losses and EMI problems that occur with higher switching frequencies in hard-switched converters. In this paper, a new, quasi-resonant, soft-switched, three-phase inverter is presented which uses 12 thyristors as the power electronic switches, and hence has potential for use in high-power applications. The converter is fully current-regulated, suitable for high-performance motor drive applications, and is capable of 4-quadrant operation to allow regeneration back into the DC supply. The operation and the control of the inverter are described in detail and simulation and experimental results are presented     

Microgrids: Architectures,Controls, Protection,and Demonstration

Abstract—In the recent years, there has been a growing interest in the concept of microgrids to integrate distributed generation systems and to provide higher reliability for critical loads. Several microgrid demonstration projects have been implemented to investigate further and advance this emerging concept. This article provides a detailed review of microgrid systems. It describes different architectures, including AC, DC, and hybrid systems. Various microgrid components, including sources, converters, and loads, are illustrated. Microgrid management and controls are discussed, and a modified natural droop control is described in detail. Both physical layers and standard protocols are explained for communication in the microgrid structure. The unique protection complexities have been raised and discussed in the presence of distributed generations and bidirectional power flow. A demonstration of a military microgrid system at Fort Sill is illustrated, and the experiment of a typical microgrid operation scenario is provided.