光纤中的四波混频及其受色散的影响

讨论了四波混频的效率及色散对四波混频的影响，并推导了四波混频光的效率公式。另外，在光纤线路中由于每段光纤的零色散波长略有不同，四波混频的发生与有均匀零色散波长光纤中的不同，本文对这种情况下的四波混频也进行了分析研究。     

紫外写入光纤光栅用特种光纤的研究

本文详细地介绍了如何加强用于制做紫外写入光纤光栅所需的特种光纤的高光敏性、温度不敏感性以及对包层模的高度抑制性等。     

Oxygen reduction reaction on nanosized manganese oxide particles dispersed on carbon in alkaline solutions

In this work a manganese oxide dispersed on a high surface area carbon powder at two ratios (Mn_yO_x/C) was evaluated as catalyst for the oxygen reduction reaction (ORR) in alkaline solutions. An impregnation method was used to prepare the catalysts, starting from a manganese nitrate precursor solution containing the carbon powder (Vulcan XC-72). A thin porous coating rotating disk electrode was employed to collect the experimental ORR polarization data and the results obtained were analyzed with the application of the flooded-agglomerate/thin film model for the catalyst layer. Results indicated that the reaction is sensitive to the manganese oxide to carbon ratio on the catalyst. The catalyst containing lower Mn_yO_x/C ratio tended to follow the peroxide pathway (2e⁻ mechanism) forming peroxide ions. When the Mn_yO_x content is increased the complete reduction of oxygen to hydroxide ions pathway (the 4e⁻ mechanism) takes place into some extent at low potentials due to the occurrence of a catalytic disproportionation of HO₂⁻.     

Design and development of a diesel and JP-8 logistic fuel processor

The paper describes the design and performance of a breadboard prototype for a 5 kW fuel-processor for powering a solid oxide fuel cell (SOFC) stack. The system was based on a small, modular catalytic Microlith auto-thermal (ATR) reactor with the versatility of operating on diesel, Jet-A or JP-8 fuels. The reforming reactor utilized Microlith substrates and catalyst technology (patented and trademarked). These reactors have demonstrated the capability of efficiently reforming liquid and gaseous hydrocarbon fuels at exceptionally high power densities. The performance characteristics of the auto-thermal reactor (ATR) have been presented along with durability data. The fuel processor integrates fuel preparation, steam generation, sulfur removal, pumps, blowers and controls. The system design was developed via ASPEN^® Engineering Suite process simulation software and was analyzed with reference to system balance requirements. Since the fuel processor has not been integrated with a fuel cell, aspects of thermal integration with the stack have not been specifically addressed.     

太阳能制氢技术研究进展

利用太阳能制氢因其具有能够有效解决能源问题、形成可持续的能源体系以及减少温室气体及有害气体的排放等优点而得到了广泛的关注。介绍了基于传统概念上太阳能制氢技术的新方法、新工艺及新材料,分析了一些技术难点,最后论述了发展太阳能制氢技术的前景并指出了今后的研究方向。     

基于Matlab/Simulink的火电厂热力系统模块化建模方法

本文以常规热平衡法为基础,引入模块建模的思想,阐述了模块化建模的开发过程,提出了一种火电厂热力系统模块化建模的方法。通过对热力系统分解、模块化,Matlab／Simulink为开发工具建立了火电厂常用设备的模型库,并给出实例验证了所提方法的正确性和可行性。     

电涡流测功机控制器控制算法研究

介绍了电涡流测功机控制器的设计开发过程,分析了控制系统模型,对系统各PID控制器进行设计和试验调试,给出了系统控制模式的控制效果。经试验验证了控制器控制效果良好,完全满足发动机台架试验对控制品质的要求。     

Periodic heat transfer by forced laminar boundary layer flow over a semi-infinite flat plate

The paper reports a study of periodic convection in a steady forced laminar boundary layer flow over a semi-infinite impermeable flat plate due to periodical variation of the wall heat flux. The Fourier transform based approach allows to obtain a transfer function for the boundary layer that can be used to solve also transient (non-periodic) heating problems, and examples are reported comparing with available studies in the open literature. The effect of periodic heating on the value of the the average heat transfer coefficient is analysed and it is found to be important for relatively high frequency fluctuations of the imposed heat flux, whereas fluctuation amplitude of the instantaneous heat transfer coefficient is non-negligible also for lower exciting frequency.     

基于混沌优化的无线定位算法研究

本文提出一种抗NLOS干扰的TDOA定位算法。基于混沌优化算法对TDOA算法做了改进,采用混沌优化算法计算初值,再利用Taylor级数展开法进行定位。根据产生混沌序列的两种映射Logistic映射和Kent映射的特点,提出了Kent-Logistic模型修正Logistic映射用于定位。在移动台距服务基站较近时,直接采用该模型进行定位。通过和传统蜂窝定位算法的仿真结果进行比较,表明提出的算法能够提高NLOS传播环境下的定位精度。