基于FBG的MFC电极界面产热实时监测方法研究

微生物燃料电池(Microbial Fuel Cells,MFC)在产电过程中,温度的变化是影响微生物反应的一个重要参数,为了提高MFC的产电效率,需要实时监测MFC内温度变化情况。本文采用光纤Bragg光栅(FBG)温度传感器对MFC阳极电极界面基质温度进行实时监测,研究了温度与MFC产电的关系。实验研究表明:当温度达到2.3℃时MFC产电达到最大值,基质温度在2.5摄氏度时微生物燃料电池产电基本保持平衡。采用FBG监测MFC的温度对MFC的研究进展具有一定的意义。     

针对微生物燃料电池能量采集的最优电容理论计算方法与实验研究

微生物燃料电池(Microbial Fuel Cells,MFCs)已被认可为最具前景的可替代、可再生的清洁能源之一,但是其输出电压和电流较小,几乎难以直接驱动目前任何商用电子器件.在实际应用中,通常需要能量管理系统(PowerManagement System,PMS)来存储其输出能量,然后经变换处理后间歇式的驱动负载.在PMS中,超级电容器通常被选作为电能存储器件.由于MFC输出能量有限,如何使最多的能量转存到超级电容器中成为MFC应用领域重要的研究内容.通过分析MFC反应机理,采用目前普遍公认的MFC等效电路模型,提出了一种计算最优电容值的理论方法,选用该最优电容,能够使MFC在一个充电周期内产生的平均功率最大.基于建立的单室空气阴极MFC实验系统,进行了最优电容值检验实验.理论和实验结果验证了该方法的有效性.     

燃料电池发动机二次开发控制系统的设计与实现

引言 质子交换膜燃料电池(Proton Exchange Membrane Fuel Cell:PEMFC)是一种将储存在燃料和氧化剂中的化学能转化为电能的发电装置,具有能量高、噪音小、无污染、零排放和能量转换效率高等特点,适合做电动汽车的动力能源.各国政府、企业和科研机构都致力于研究质子交换膜燃料电池电动汽车,而燃料电池发动机作为其核心目前处于突破前期,正在成为新的研发热点.     

业界热点

便携式燃料电池迈向实用化日前在美国举办的“Small Fuel Cell2004”研讨会上,众多厂商公布了各自在便携式燃料电池领域的研发进展。三星尖端电子研究所(SAIT)已试制成功输出功率为20W的燃料电池系统,可支持笔记本电脑工作10小时,三星计划在明年底投产使用燃料电池的笔记本电脑。Motorola则决定暂时中止直接甲醇型燃料电池的开发,转而加紧开发一种“甲醇改质型”燃料电池,将甲醇改质提取氢气后供给燃料电池的燃料极。德国Smart Fuel Cell公司上市的产品是平均输出功率为25W的便携式燃料电池。此外,该公司还计划在明年底上市专门面向笔…     

以氢和氧为燃料的燃料电池电动汽车

作为环境保护的对策之一,丰田汽车公司从1971年开始进行了对电动汽车的研究和开发,并于1996年10月在日本首家推出了安装着以氢为燃料的燃料电池(Fuel Cell)的电动汽车(Fuel Cell Electric Vehicle,简称FCEV),燃料电池作为划时代的动力能源而备受关注。 通过施加电压,水会被分解为氢和氧。燃料电池发电的系统就是利用水的这种电分解原理。从氢和氧两者的化学反应的过程中获得     

新型技术有望造就体积更小、重量更轻的燃料电池

由能源系统开发商CMR Fuel Cells公司(位于英国剑桥)推出的小型混合反应剂(compact mixed-reactant，CMR)技术采用了混合反应剂和流经多孔电池结构的液体，旨在大幅度地降低对燃料电池的材料要求，有望使现用电池的体积和重量实现高达90％的降幅，而且价格也更加便宜。这种更轻、更便宜的燃料电池将造就无须安装电池的便携式电子设备，而且几乎(或根本)不会对封装和成本产生任何不利的影响。     

基于动态神经网络的质子交换膜燃料电池建模方法

针对现有质子交换膜燃料电池(Proton Exchange Membrane Fuel Cell,PEMFC)模型逼近能力不足、自适应性差的问题,提出一种基于动态神经网络的PEMFC建模方法.该方法引入神经网络输出敏感度作为隐含层结构合理性判别依据,根据敏感度分析结果选择采用相应的神经元修改算法调整隐含层结构,使隐含层神经元数目根据燃料电池数据处理需求动态变化,实现模型结构与参数的双重优化.以某型双系统燃料电池测试平台实际运行数据为例进行验证,结果表明构建的PEMFC动态神经网络模型比传统模型的网络规模小、拟合精度高、收敛速度快,适用于工程化仿真应用.     

燃料电池

Y2000-62240-1 0014307电动车辆用的燃料电池的问题与进展=Fuel cell forelectric vehicles:issues and progress[会,英]/MacArthur,D.//The Fourteenth Annual Battery Con-ference on Applications and Advances.—1～4(PC)Y2000-62240-5 0014308未来的电动车辆用的燃料电池=Fuel cells for futrueelectric vehicles[会,英]/Kalhammer,F.R.&Prokopius.P.R.//The Fourteenth Annual Battery Con-ference on Applications and Advances.—5～10(PC)Y2000-62240-73 0014309直接甲醇燃料电池的最新进展=Recent advances in di-rect methanol fuel cells[会,英]/Narayanan,S.R.&Valdez.T.//The Fourteenth Annual Battery Conferenceon Applications and Advances.—73～77(PC)     

燃料电池引爆便携式革命

目前的便携式电子产品是以二次电池作为主流电力解决方案,为了寻找更具环保概念与更长使用寿命的能源,燃料电池(Fuel Cell)技术逐渐崭露头角。燃料电池其实并非只是单纯的蓄电装置,而是一个完整的发电系统,过去的研究主要是大型发电机具或是电动车的应用,近年来将燃料电池系统小型化以供3C产品之应用,则成为全球许多厂商努力的目标。燃料电池是一个全新的能源概念,称其为“电池”甚至稍嫌狭隘,燃料电池与二次电池最大的不同之处,就是可藉由直接供应燃料的方式产生电能,就像是小型的发电机;而因为目前燃料电池在瞬间电压与电流量上仍有其瓶…     

硅基微型直接甲醇燃料电池的研究

设计了一种基于MEMS技术的硅基微型直接甲醇燃料电池(DMFC),采用流体力学软件进行了DMFC三维阳极模型的模拟,利用MEMS加工技术和PDMS封装工艺实现了这种燃料电池,并在室温下对有效面积为8600μm× 8600μm的电池样品进行了性能测试.测试得到该DMFC的开路输出电压为0.5V,短路工作电流密度达到78.1mA/cm2,最大输出功率密度为3.86mW/cm2.主要参数已达到了一些电子器件的要求,具有一定的实用价值.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.