基于电量时序特征的旁路代自动识别和代入算法

介绍了一种基于时序特征的电能量计量计费系统（TMR）的旁路代自动识别和代入算法。首先分析了现有TMR中的旁路代处理方式，指出这些处理方式的缺陷;然后通过分析TMR旁路代发生前后电量的时序特征，提出了一种基于电量时序特征的自动旁路代算法，此算法能在旁路代事件开始时即做出正确判断，并在适当的延时后开始完成旁路电量的自动代入。该算法在江苏省电力公司TMR中获得了很好的实验效果。     

机载雷达成像中的两种改进多普勒质心估计算法

多普勒质心估计是机载脉冲多普勒雷达DBS成像技术中最为关键的步骤之一.本文针对载机惯导参数误差较大的实际情况,提出了改进的频域和时域多普勒质心估计算法.新的算法克服了传统算法受地面场景非均匀性和回波信号起伏的影响,大大提高了估计的精度.最后将这些算法用于某型脉冲多普勒雷达的实测数据,成像结果证明了算法的有效性.     

Non-contact flood discharge measurements using an X-band pulse radar (I) theory

This article describes a non-contact method for measuring surface velocity and discharge in a natural channel. The X-band pulse (9.36 GHz) radar, developed by the Applied Physics Laboratory of the University of Washington, was used to scan instantaneously the lateral distribution of surface velocity across a river section, according to Bragg scattering from short waves produced by turbulent boils on the surface of the river. Based on the assumption that the vertical velocity distribution follows a universal power or logarithmic law, the discharges were estimated.     

光纤光栅的长度对其峰值反射率的影响

利用耦合模理论,数值分析了当光纤光栅(FBG)折射率变化为均匀分布、直流切趾高斯分布时,光纤光栅长度对其峰值反射率的影响。研究结果对光纤光栅外腔半导体激光器的设计和性能优化具有重要的意义。     

On using peak amplitude and rise time for AE source characterization

Acoustic Emission (AE) signals, which are electrical version of acoustic emissions, are usually analysed using a set of signal parameters. The major objective of signal analysis is to study the characteristics of the sources of emissions. Peak amplitude(P _a ) and rise time(R _t ) are two such parameters used for source characterization. In this paper, we theoretically investigate the efficiency ofP _a andR _t to classify and characterize AE sources by modelling the input stress pulse and transducer. Analytical expressions obtained forP _a andR _t clearly indicate their use and efficiency for source characterization. It is believed that these results may be of use to investigators in areas like control systems and signal processing also     

Criterion of Magnetic Saturation and Simulation of Nonlinear Magnetization for a Linear Multi-core Pulse Transformer

The linear multi-core pulse transformer is an important primary driving source used in pulsed power apparatus for the production of dense plasma owing to its compact,relatively low-cost and easy-to-handle characteristics.The evaluation of the magnetic saturation of the transformer cores is essential to the transformer design,because the energy transfer efficiency of the transformer will degrade significantly after magnetic saturation.This work propses analytical formulas of the criterion of magnetic saturation for the cores when the transformer driver practical loads.Furthermore,an electric circuit model based on a dependent source treatment for simulating the electric behavior of the cores related to their nonlinear magnetization is developed using the initial magnetization curve of the cores.The numerical simulation with the model is used to evaluate the validity of the criterion.Both the criterion and the model are found to be in agreement with the experimental data.     

宽带抽运情况下乙醇、丙酮溶液中受激拉曼散射光谱的实验研究

研究了乙醇、丙酮两种拉曼介质在宽带抽运情况下啁啾激光脉冲的受激拉曼散射频谱特性 ,得到的一级Stokes光频谱宽度与抽运光基本相当 ,且具有较高的转换效率 ,从而表明了利用“展宽—受激拉曼散射—压缩”的办法获得波长近 1μm的飞秒级超短脉冲激光信号源的实验方案具有可行性     

Mechanical and thermal properties of HVOF sprayed Ni based alloys with carbide

The objective of the present study is to develop multi-functioned coating to the components, which are made of copper with electroplated Ni and are widely used for steel making industry. In this paper, we report the mechanical and thermal properties of Ni based superalloys with carbide sprayed by high velocity oxygen fuel (HVOF), and the detailed effects of sprayed material, spraying conditions, and initial powder structure on these properties. It was found that, among commercial Ni self-fluxing alloys (without fusing treatment), coating with a carbon content of 0.58 mass% had the most preferable properties, with a good balance of the hardness, strength, and thermal shock resistance. The thermal shock resistance depended not only on the strength of the coating but also on the volume contraction when tested at high temperatures. For the several developed Ni based superalloys with carbide, Ni20Cr8Mo5Fe–WC and Ni16Cr15Mo3–WC demonstrated the prominent adhesion strength and thermal shock resistance with high Galvanic corrosion resistance through optimized spraying condition. Also, 20 mass% NiCr–Cr₃C₂ coating sprayed by using employed relatively small primary particle succeeded in achieving the multi-superior properties; high adhesion strength, high corrosion resistance and thermal shock resistance.     

A Novel UWB Pulse Shape Modulation System

In this paper novel modified Hermite polynomial functions for use in impulse radio (ultra-wideband) communications are proposed. With these functions pulse shapes which are orthogonal and have nearly constant pulse width regardless of the pulse order are generated. These properties hold under the effects of differentiation. An M-ary communication system is constructed using these pulse shapes. A Matlab model for generating the pulses is designed and the effect of timing jitter on the performance of the system is investigated by computer simulation.     

调制脉冲声测量系统的原理及应用

本文介绍的调制脉冲声测量系统是TDS和数字测量技术的进一步发展,其特点是简化了TEF系统的实现条件,解决了全频带的测量动态问题。本系统曾在上海音像公司录音棚中进行过测量,取得了一定的效果。