超大容量双电层电容器的研制

双电层电容器是一种功率密度高和能量密度大的新型储能元件。研究以活性炭为材料的双电层电容器的制作，对制作压力、活性物质涂载量及电解液浓度进行了研究，摸索出电容器的制作工艺。实验过程中采用循环伏安、交流阻抗和恒电流充放电方法对电极和电容器进行性能测试。结论是活性炭电极在制作压力为20MPa，活性物质涂载量为30mg／cm^2，电解液为7moL／L的KOH水溶液时性能最优。实验单体小电容器的比容量可达54．01F／g，并研制出容量高达1247．32F的超大容量电容器。     

加湿除湿脱盐系统的热力学分析及实验研究

基于加湿除湿(HDH)原理,搭建在低温常压下运行的新型脱盐系统,详细介绍系统的结构和工作原理. 在相关假设的基础上对加湿除湿过程进行热力学分析,开展空气循环体积流量、进料体积流量和料液温度等操作参数对系统产水性能影响的实验研究. 实验结果表明,系统产水量随着料液温度和进料体积流量的增加而增大;与预期相反,系统产水量随空气循环体积流量的增加而先增大后减小;当进料体积流量为60 L/h、料液温度为57 °C、空气循环体积流量为180 m³/h时,系统最大产水量和脱盐率分别达到1.7 kg/h、大于99.99%;当料液温度为38 °C时,系统最大造水比和单位体积产水能耗分别为3.8、166 kW·h/m³. 由于具有结构紧凑、模块化设计、操作简单、维护成本低、可以与可再生能源结合等特点,该系统在海水淡化领域颇具竞争力. 上述研究表明,该系统虽然有很大的提升空间,但很有希望应用于分散式小规模淡水生产.     

Influence of polyethylene glycol on pore structure and electric double-layer capacitance of carbon xerogel

Mesoporous polyethylene glycol-resorcinol and formaldehyde(PEG-RF) carbon xerogels were prepared by a new polymer blend method in which PEG-RF mixed organic xerogels were synthesized by blending thermally unstable polyethylene glycol with organic monomers, resorcinol and formaldehyde and then subjected to pyrolization at 1 000℃. The influences of mass ratio of PEG to the theoretical yield of RF xerogel, m(PEG)/m(RF) and the relative molecular mass of PEG on the pore structure and electric double layer capacitance(EDLC) performance of PEG-RF carbon xerogels were investigated. The results show that PEG under different conditions leads to the difference of phase separation structure of the polymer blend and thus the change of pore structure of PEG-RF carbon xerogels. Specific surface area and capacity of PEG-RF carbon xerogels in 300/60 H2SO4 solution can reach 755 m^2/g and 150 F/g, respectively. Their surface can be fully utilized to form electric double layer. However, the pore structure differences of PEG-RF carbon xerogels result in their different EDLC performances. The distributed capacitance effect increases with decreasing the pore size of PEG-RF carbon xerogels.     

软件进程分解的理论分析

讨论了软件进程SP分解运算的理论基础及分解运算集合ρθ的数学表示和性质；说明了SP作为一个模块M对它分解运算的一般模型和谓词公式；分析了等价算子集ASeteq(M)及其相关结论。     

电场辅助离子扩散过程中玻璃基片的电导变化

实验研究了玻璃基片在电场辅助离子扩散过程中的电导变化规律。结果发现,由于直流电场在玻璃基片中产生的焦耳热效应,离子扩散过程中玻璃基片的温度会明显升高,玻璃基片的电导也按照相应的规律变化;在通常的离子扩散制备掩埋式光波导的过程中,玻璃基片电导值可以增加到初始值的数倍;这种玻璃基片温度及伴随的电导变化,会给玻璃基离子交换光波导制备工艺带来不可忽略的影响。     

一种微型声光电导笔的研制

针对大学化学实验,研制了一种微型声光电导笔。该电导笔采用声音和灯光同时指示导体电导的大小,具有直观、现象明显,并有半定量的指示效果;其体积较小,便于携带;不必用交流电源,操作简单、安全,实验成功率高;且造价较低,适合于推广普及。     

Adsorption of K+ from an aqueous phase onto an activated carbon used as an electric double-layer capacitor electrode

The adsorption capacity and absorption rate for electrolyte onto activated carbon are important parameters used to characterize activated carbon electric double-layer capacitor electrodes. In this paper the pore structure of typical commercial activated carbons, and various Mn-doped activated carbons prepared on a laboratory scale, are described. The pore structure was characterized by N2 adsorption/desorption isotherms. Isotherms for K+ adsorption onto these activated carbons from the aqueous phase were also obtained. The experimental, equilibrium K+ adsorption data were fitted to the Langmuir, Freundlich or Temkin equations. Adsorption of K+ onto the activated carbons was measured and plotted as a function of time. The adsorption kinetic data were modeled by either pseudo-first or pseudo-second order equations. The Elvoich equation, a liquid film diffusion and an intra-particle diffusion model were used to fit the kinetic data. The results indicate that the adsorption of K+ onto activated carbon is influenced by many factors including pore size distribution, specific surface area and the surface chemistry of the activated carbons. The Temkin equation best describes the equilibrium adsorption data. The pseudo-second order model exactly describes the whole adsorption process, which is controlled by both liquid film and intra-particle diffusion.     

30kW级航空电驱动涵道风扇设计与试验

电驱涵道风扇因其低油耗,更加符合航空绿色、高效、安全的发展目标。开展电驱动涵道风扇动力研究具有重要的工程实践意义。文章首先使用数值模拟方法对4种不同唇口构型的涵道风扇性能进行研究,并搭建动力测试平台进行验证,在回流风洞中对不同唇口构型的涵道风扇进行推力测试,研究不同唇口构型对小型电驱涵道风扇气动性能的影响。研究结果表明：不同唇口构型涵道风扇的气动差异较明显;涵道风扇唇口半径增大使涵道进气量增大进而增加涵道推力,但过大的唇口半径在较大风速（31 m/s以上）时会增加涵道风扇的风阻,在流场上表现为涵道唇口处产生漩涡结构,影响涵道风扇的气动性能;在100%油门开度、14.2 m/s风速时,相比于内敛式进气唇口,喇叭状、外扩式进气唇口构型的净推力分别提高了17.58%、12.77%;在49.3 m/s风速时,喇叭状进气唇口的风阻相比内敛式进气唇口的增加了14.85%。

     

《电工学》实验教学改革探讨

根据《电工学》实验教学的实践，提出加强实验教学研究和挖掘实验教学的潜力是培养开拓型人才的重要途径，并对实验教学中存在的问题进行了初步探讨。     

自动化电解去内交叉孔毛刺过程的仿真与实验

针对零件内部交叉孔相贯线处的毛刺去除困难的现状,利用电解加工的原理,采用插孔固定阴极式的电极布局形式,提出基于电流检测的自动电解去毛刺的方法.建立电解去毛刺的数学模型,用仿真和实验研究电解去毛刺过程中加工间隙、加工电压及加工时间对毛刺去除的影响,分析去毛刺过程中电流密度随时间的变化规律.在该电极布局形式下,毛刺与工件间的平均电流随着毛刺的去除逐渐下降,且电流曲线的斜率在毛刺完全去除后趋近于0.以此作为去除过程是否完成的判断依据,研制了自动电解去毛刺的控制系统并完成了自动化去毛刺实验.实验结果表明:该方法能够有效地对毛刺大小进行判断,可以控制加工时间进行精确的毛刺去除,成本低、安全可靠.     

Experimental study on the performance of a rotational supercavitating evaporator for desalination

Efforts have been made on experimental research of a supercavitation device for desalination,which is named rotational supercavitating evaporator(RSCE).The RSCE is characterised by the simple construction and responsive capacity control,and only requires rough filtration of the source water for scaling-and fouling-free operations.The present study has been conducted for the water flow at temperature of around 22–30°C and atmospheric pressure as the first step for investigation of the performance characteristics of RSCE.The multiply factor extremal experiments conducted with the Box-Wilson’s method have revealed the salinity of the condensate,the temperature of steam inside the supercavity,and dependence of the shape of supercavity on the rate of steam extraction and rotation speed of impeller.The shape of impeller and the expected supercavitating effects it generates have been confirmed by experimental results at the rotation speed of 5430 rpm(round per minute).The design of the steam extraction openings has been approved during the evacuation of steam.The experimental dependencies have been obtained in form of statistically valid regression equations,which can be used for engineering design of RSCE.     

电火花技术在成型磨削加工中的应用

采用电火花加工技术和计算机控制技术 ,对成型磨削的方法进行了研究 .利用高纯石墨作磨轮电极材料 ,并将其预加工成型 ;通过计算机系统控制磨轮电极与工件间的相对运动及火花放电的参数 ,完成对工件的成型磨削加工 ;利用预成型的样板刀对磨轮进行实时修整与补偿 ,可以极大的减少电极损耗对磨削精度和表面粗糙带来的不利影响 .该技术和方法较好地解决了传统方法难以加工的高硬度、易碎和易变型等零件的成型磨削问题 .文中给出了磨轮半径损耗值的估算公式     

给水温度对MSF海水淡化系统性能的影响

从理论上研究了给水温度对多级闪蒸海水淡化系统性能的影响,讨论了给水量温度对冷却不量,造水比影响及总换热面积对系统的设计与运行的影响。     

湍流条件下氧的传质过程对舰船混合电场的影响

为研究航行状态下舰船混合电场的产生机理及变化规律,基于电化学原理及流体动力学相关理论,分析湍流流场、舰船电场等多物理场耦合建模理论基础,结合轴频电场中舰船轴系机械结构等效电路电阻变化规律,最终采用边界元法建立湍流介质条件下潜艇腐蚀混合电场模型,分析不同螺旋桨转速及介质流速下舰船静电场及轴频电场变化规律。结果表明：螺旋桨转速由0 r/s增长至1、2、3、4 r/s时,螺旋桨正下方2B(B为船宽)处舰船混合电场幅值依次增长了66.5%、13%、3.7%、1.19%,且混合电场频率与螺旋桨转速一致。该模型对分析运动状态下舰船电场变化规律提供了理论参考。     

Oxidation behavior of CNTs and the electric double layer capacitor made of the CNT electrodes

Electric double layer capacitors (EDLCs) have been widely used because they have large capacitance, and are free of maintenance and free from toxic materials. After NEC corporation developed activated carbon/carbon super capacitor, they are expected to be applied to electric vehicles[1]. A unit of EDLCs is based on the double layer capacitance at solid/solution interface of high surface material. As in the case with a traditional electrolytic capacitor, the electrical energy is stored thro…     

Analysis on electric energy measuring method based on multi-resolution analysis

In recent years,with the extensive applications ofthe non-linear loads,many non-stationary stochastic sig-nals such as harmonics,inter-harmonics,and impulsesignals have been introduced into the electric network,resulting in the decline in the quality of e…     

电网信号数学描述及电能计量方法分析

分析非线性负载和冲击性负载对电能质量的影响,给出符合电网信号实际情况的、适用范围更宽的基于随机过程理论的电网信号数学描述.并据此分析了现有电能计量方法产生巨大误差的原因,提出解决问题的方案,给出仿真结果,对提高现有电能计量水平有一定的参考价值.     

基于ANSYS Workbench的电动车车架疲劳分析

为优化电动车车架设计及后续改进,通过三维软件Solidworks对电动自行车车架进行三维建模,并导入ANSYS Workbench软件从而获得有限元模型.根据车架实际试验要求,对有限元模型进行结构的静力分析,获得车架各部分应力应变情况,随后分别进行恒定载荷疲劳分析和随机载荷疲劳分析;在此基础上,对车架在不同工况环境下的寿命进行分析评估,探讨不同工况下寿命随载荷的变化情况,找出应力集中部位和容易产生失效的部位.     

大型电力网络系统抗震可靠度分析

提出了一类计算大型点权网络系统可靠度的递推分解算法。在此基础上，建议了设定地震影响场条件下的区域电力系统抗震可靠度的分析方法。文中给出的分析实例表明了递推分解算法的高效性质，也说明了区域电力系统抗震可靠性分析的重要性。     

一维光栅结构中电场分布的计算分析

光栅中的电场分布对光栅的激光损伤阈值具有重要影响,为此提出了一种计算一维光栅结构中电场分布的方法,该方法对于任意深度和占空比的光栅,均能计算得到光栅内外的电场分布.采用解析方法推导得到了计算公式,由于矩阵中元素值太小而无法求逆矩阵,应用基于增强透射矩阵的耦合波理论, 并对其计算过程进行了改进,改进方法能够直接计算得到单层光栅的电场分布.进一步将该方法运用到多层光栅结构中,能够计算光栅和介质多层薄膜混合结构的电场分布.计算结果表明,采用该方法能够直接分析计算介质反射光栅内的电场分布,不仅可以获得精确解,而且可以大大降低计算量.