车用直喷式柴油机燃油系统匹配技术的研究

车用直喷式柴油机燃油喷射系统的选型、参数合理选择和优化及其与整机的匹配试验工作量大 ,要求越来越高 ,是柴油机设计、改进和性能开发过程中最关键的工作。本文从现代车用直喷式柴油机的特点及其对燃油喷射系统的要求出发 ,详细阐述了喷射系统的匹配过程和基本步骤、匹配的流程、采用的主要方法以及常用的主要技术手段。     

基于32位RJSC处理器之SoC平台的Linux操作系统实现

介绍了如何在兼容ARM V4指令集的32位RISC处理器（FA526）所构建的SoC平台上（即FIE8100），运用智原科技所提价的FA526-Linux开发包通过armboot装载Linux操作系统。使开发人员可以在基于FIE8100 SoC的仿真平台-MediaCreative！在进行二次开发和验证的设计方法。     

柴油喷射系统的发展现状及潜力（下）

车用柴油机现在正面临降低有害排放和优化燃油经济性的重大挑战。对于柴油机技术来说 ,喷油系统技术的发展已成为柴油机达到排放指标的决定性因素。喷射压力已从 5 0MPa逐步增加到了 2 0 0MPa ,高控制柔性的喷油系统必须能够进行多次喷射和喷油规律控制。喷油系统本身具有高的效率是非常重要的。为了喷油系统的进一步发展 ,新技术如变喷孔面积的喷油嘴技术和新的执行器技术等等是关键的因素。用柔性控制的喷油系统 ,就有可能获得最佳的排放组合和燃油经济性的折中。     

基于FIE8180芯片H.264视频记录系统设计

视频压缩协议H.264能比其它视频压缩协议表现出更好的性能,更能适应无线多媒体和网络多媒体的应用需求.本文设计出一种以FIE8180为核心处理器,辅以外围电路的H.264视频记录系统.由于FIE8180是基于SoC结构的H.264/MPGA多媒体数字信号编解码器,使得整个视频记录系统速度快、功耗低、工作稳定.     

基于32位超高速RISC体系处理器之SoC平台的Linux2.6操作系统

本文介绍如何在兼容ARMV4指令集的32位超高速RISC处理器（FA626）所构建的SoC平台上（即FIE8180），运用智原科技所提供的FA626-Linux开发包通过armboot装载Linux2．6操作系统。使开发人员可以在基于FIE8180 SoC的仿真平台-MediaCreative!上进行二次开发和验证设计。     

New Technique for Estimating and Suppressing Narrowband Interference in DSSS Systems

A generalized approach for narrowband interference （NBI） suppression in direct sequence spread spectrum （DSSS） communication systems using adaptive infinite impulse response （IIR） filter is presented. The excision filter coefficients depend on both the jammer power and its instantaneous frequency. The dependency of the filter construction on the jammer power is significant as it allows optimal tradeoff between interference removal and signal distortion by maximizing the receiver signal to noise ratio improvement（SNRI）. Instead of traditional adaptive line enhancer （ALE） estimator, a preferable NBI estimator-Fourier interpolation estimator （FIE） is proposed. Closed-form expressions of the SNR improvement and theoretical bit error rate （BER） based on the assumption that the output of the correlator is Gaussian distributed are both derived. Performance results obtained by numerical simulation are also presented and compared with theoretical results.     

柴油喷射系统的发展现状及潜力（上）

车用柴油机现在正面临降低有害排放和优化燃油经济性的重大挑战。对于柴油机技术来说 ,喷油系统技术的发展已成为柴油机达到排放指标的决定性因素。喷射压力已从 5 0MPa逐步增加到了 2 0 0MPa ,高控制柔性的喷油系统必须能够进行多次喷射和喷油规律控制。喷油系统本身具有高的效率是非常重要的。为了喷油系统的进一步发展 ,新技术如变喷孔面积的喷油嘴技术和新的执行器技术等等是关键的因素。用柔性控制的喷油系统 ,就有可能获得最佳的排放组合和燃油经济性的折中     

基于查找表和SF CORDIC的高精度正余弦函数求值方法

常用查找表法和CORDIC算法在FPGA上实现正余弦函数求值.查找表法实现简单,输出延迟小,但随着计算精度的提高,存储资源需求呈指数增长;传统的CORDIC方法硬件资源消耗大,且输出时延长.论文提出一种新方法,将查找表和SF-CORDIC算法相结合,以查表所得中间向量为迭代初始向量,对剩余旋转角应用SF-CORDIC算法,迭代系数取0或1,减少了x、y通路的计算开销和舍入误差;并对z通路使用加减交替法提前生成剩余旋转角,以减少每级流水线的延迟.所需查找表的地址位数和迭代次数分别较常规查表法和CORDIC算法减少一半左右.基于FPGA完成了算法的设计、仿真与误差分析,结果表明该方法可利用较少的硬件资源和存储资源实现较高精度和较低时延的正余弦函数求值.     

The potential of di-methyl ether (DME) as an alternative fuel for compression-ignition engines: A review

This paper reviews the properties and application of di-methyl ether (DME) as a candidate fuel for compression-ignition engines. DME is produced by the conversion of various feedstock such as natural gas, coal, oil residues and bio-mass. To determine the technical feasibility of DME, the review compares its key properties with those of diesel fuel that are relevant to this application. DME’s diesel engine-compatible properties are its high cetane number and low auto-ignition temperature. In addition, its simple chemical structure and high oxygen content result in soot-free combustion in engines. Fuel injection of DME can be achieved through both conventional mechanical and current common-rail systems but requires slight modification of the standard system to prevent corrosion and overcome low lubricity. The spray characteristics of DME enable its application to compression-ignition engines despite some differences in its properties such as easier evaporation and lower density. Overall, the low particulate matter production of DME provides adequate justification for its consideration as a candidate fuel in compression-ignition engines. Recent research and development shows comparable output performance to a diesel fuel led engine but with lower particulate emissions. NO_x emissions from DME-fuelled engines can meet future regulations with high exhaust gas recirculation in combination with a lean NO_x trap. Although more development work has focused on medium or heavy-duty engines, this paper provides a comprehensive review of the technical feasibility of DME as a candidate fuel for environmentally-friendly compression-ignition engines independent of size or application.