2.3–21 GHz broadband and high linearity distributed low noise amplifier

This paper focuses on the design of a 2.3–21 GHz Distributed Low Noise Amplifier (LNA) with low noise figure (NF), high gain (S₂₁), and high linearity (IIP3) for broadband applications. This distributed amplifier (DA) includes S/C/X/Ku/K-band, which makes it very suitable for heterodyne receivers. The proposed DA uses a 0.18 μm GaAs pHEMT process (OMMIC ED02AH) in cascade architecture with lines adaptation and equalization of phase velocity techniques, to absorb their parasitic capacitances into the gate and drain transmission lines in order to achieve wide bandwidth and to enhance gain and linearity. The proposed broadband DA achieved an excellent gain in the flatness of 13.5 ± 0.2 dB, a low noise figure of 3.44 ± 1.12 dB, and a small group delay variation of ±19.721 ps over the range of 2.3–21 GHz. The input and output reflection coefficients S₁₁ and S₂₂ are less than −10 dB. The input compression point (P_1dB) and input third-order intercept point (IIP3) are −1.5 dBm and 11.5 dBm, respectively at 13 GHz. The dissipated power is 282 mW and the core layout size is 2.2 × 0.8 mm².     

适合WSN的超宽带两步TOA估计算法

结合低速率能量检测与高速率匹配滤波的两步超宽带TOA估计算法适合WSN定位。通过采样获得低速率能量序列,找出直达路径(direct path,DP)在序列中的位置,即TOA粗估计。在该能量采样周期内进行相关滤波,由相关峰确定DP位置,即TOA精确估计。能量采样周期、能量块选择门限、相关峰检测门限是TOA估计的关键参数,对它们进行讨论,并给出一种基于最大最小能量比(MMR)的归一化门限模型。在IEEE 802.15.4a信道下的仿真结果表明：算法的运算量低于单一滤波匹配算法,精度优于基于能量检测的非相干算法     

汽车行驶记录系统中AT89C51ED2的设计与实现

本文介绍了AT89C51ED2在汽车行驶记录仪中的实现.该记录仪采用大容量闪速存储器FM1808作为存储栽体,利用定时器中断方式来实现秒间隔的数据采集与存储,利用串行口中断方式实现与微机的数据通信,通过USB HOST和IC卡实现对车辆记录数据的快速下载和出行任务的灵活设置.     

An EDBoost algorithm towards robust face recognition in JPEG compressed domain

In this paper, we describe a novel multiclass boosting algorithm, EDBoost, to achieve robust face recognition directly in JPEG compressed domain. In comparison with existing boosting algorithms, the proposed EDBoost exploits Euclidean distance (ED) to eliminate non-effective weak classifiers in each iteration of the boosted learning, and hence improves both feature selection and classifier learning by using fewer weak classifiers and producing lower error rates. When applied to face recognition, the EDBoost algorithm is capable of selecting the most discriminative DCT features directly in JPEG compressed domain to achieve high recognition performances. In addition, a new DC replacement scheme is also proposed to reduce the effect of illumination changes. In comparison with the existing techniques, the proposed scheme achieves robust face recognition without losing the important information carried by all DC coefficients. Extensive experiments support the conclusion that the proposed algorithm outperforms all representative existing techniques in terms of boosted learning, multiclass classification, lighting effect reduction and face recognition rates.     

Treatment of electroplating wastewater

To study the feasibility of treated water being used as rinsing water with CP/ED (chemical precipitation/ electrodialysis) system, the relation between concentration of Cr (Ⅵ) and conductivity of water is investigated, the effect of electrodialysis (ED) for different wastewater is also studied. And several parameters of importance that are relevant to the process are identified. Analysis of ICP (Inductively coupled plasma) and IC (Ion chromatography) shows that the main reason of conductivity increase in CP treated water is the increase of Na+ and Cl- ions. The 93.8%-100% of ions from wastewater both in ED and CP/ED systems was removed successfully. The results of experiments indicate that the CP/ED system is a feasible method for electroplating wastewater treatment, the CP/ED system used as a way of wastwater is not only in favour of environment, but also economic beneficial to achieve.     

基于MapReduce的XML编码研究

XML因其自描述性和可扩展性作为网络中一种主要数据形式得到越来越多的应用,单一XML文档数据量变得越来愈大,如何有效求解满足一定查询语义的结果是XML数据查询技术的一个核心问题,其中基于XML文档对应文档树采用的编码是影响查询效率的关键因素。本文实验过程是通过MapReduce计算框架完成,将前缀流编码作为研究对象,提出了一种新的编码MINDewey码。对比Dewey码,ED码,通过在分布式集群下编码效率提高了至少10%。     

自举式2ED020I12-F芯片在IGBT驱动电路中的应用

介绍了自举式2ED020112-F驱动芯片的内部结构和特点,对其典型应用电路做了详尽的分析,提出了自举电路中二极管和自举电容的计算方法、电流检测电路、负压电路设计方法以及应用中的一些抗干扰技术,并在实际应用中验证了这种驱动芯片性能好、体积小、价格低、可靠性高等特点。     

尼龙1010在熔融峰温等温结晶生成晶体的热性质和形态结构

用DSC、TEM、ED研究了尼龙1010在熔融峰温等温结晶生成晶体的热性质和形态结构。结果表明该晶体在DSC扫描的时间尺度范围内是稳定的,能保持原有的熔融特性,不是低熔点晶体转化而成的晶体。对该晶体进行的电子衍射,显示出对称清晰的单晶电子衍射斑点,用尼龙1010的晶胞参数标定电子衍射图,证明是单晶的电子衍射图。     

螯合性表面活性剂的制备工艺与应用性能（Ⅱ）——ED3A蝥合性表面活性剂的合成

以ED3A为亲水基团的螯合性表面活性剂同时具有良好的表面活性和络合金属离子的作用。介绍了N-酰基ED3A和N-烷基ED3A两类螯合性表面活性剂的制备工艺，并对现有各种工艺路线的优缺点做了评述，预计了其工业发展前景，展望了此类螯合性表面活性剂的发展方向。     

Formation of CuInSe2 thin films on flexible substrates by electrodeposition (ED) technique

This work reveals the formation of electrodeposition (ED) of CuInSe₂ (CIS) film on flexible substrate. Ternary compounds were co-deposited on Au coated plastic substrate from an aqueous acidic solution containing 1 mM CuCl₂, 5 mM InCl₃ and 1 mM SeO₂ adjusted to pH=1.65. It was found that the film stoichiometry improves when the growth solution consisted of 1 M triethanolamine (TEA) and 0.1 M Na-citrate. The optimal ED-CIS film was obtained after annealing at 150°C for 1 h in a nitrogen (N₂) atmosphere. Optical absorption study showed that the energy gap of the annealed material is 1.18 eV. Good and reliable quality ED-CIS film was grown in this research with the potential use in fabricating flexible solar cells. This was supported by various analytical techniques, including energy dispersive spectroscopy (EDS), X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), ultraviolet/visible spectroscopy, Fourier transform infrared spectrometer (FTIR) and photoelectrochemical (PEC) characterization.