Investigation on Single-Mode–Multimode– Single-Mode Fiber Structure

This paper presents an investigation on a single-mode-multimode-single-mode fiber structure. A one-way guided-mode propagation analysis for the circular symmetry waveguide is employed to model the light propagation and the approximated formulations are derived and evaluated concerning the accuracy. Phase conjunction of the multimode interference within the fiber structure is revealed. A simple way to predict and analyze the spectral response of the structure is presented through the space to wavelength mapping with the derived approximated formulations. The prediction of spectral response is verified numerically and experimentally.     

合成氨催化剂的生产和技术

介绍了世界合成氨催化剂发展历程、新开发的合成氨催化剂种类 ,同时评述了我国化肥催化剂研发和生产近况 ,对我国化肥催化剂性能进行了评价。     

32位MIPS微处理器中乘法器的设计和实现

在Booth算法的基础上,结合MIPS 4KC微处理器中的流水线结构和乘法器的工作过程,提出了一种改进的Booth乘法器的设计方法,并采用全制定方法实现,用这种方法实现的乘法器单元具有面积小、单元电路可重复性好、版图设计工作量小、功耗低等特点.     

FATIGUE CRACK GROWTH UNDER MODE II LOADING

Abstract— The behavior of fatigue crack growth for low and medium carbon steels, an austenitic stainless steel and an aluminum alloy under pure Mode II loading was investigated experimentally, using cruciform specimens. The results show that under pure Mode II loading, fatigue crack propagation has three possibilities, namely, bifurcation into two branches, propagation along the original Mode II direction, and the mixture of these two situations, depending on the material. The growth rate da/dN vs. ΔK_II relation for Mode II propagation is similar to a Pans type law for Mode I growth. Fractographic observations by optical microscopy and SEM were made also on all specimens tested. When a crack branched, striations parallel to the crack front which were often associated with Mode I fatigue crack growth were observed and long marks parallel to the crack propagation direction were also found for slanted fracture surfaces. When a crack propagated along the original Mode II direction, many frictional marks parallel to the crack propagation direction were observed.     

带限信号高频重建的一种新的正则外推算法

本文提出生种新的带限信号的外推方法，该方法能够很好地抑制噪声干扰，且计算复杂性较低，本文给出算法，证明了收敛性，最后给出了误差计算机实验结果。     

超短脉冲在远场的时空特性

将在时间和空间上为高斯型的超短脉冲分解成不同时间频率的高斯光束．详细地分析了其远场由于时空耦合引起的光谱频移、波前弯曲等复杂的时空特征。     

计算机串行通信综述

本文着重向读者介绍目前流行的几种计算机串行通信规程，它们是ＥＩＡ－ＲＳ－２３２Ｃ、ＥＩＡ－ＲＳ－４２２Ａ、ＥＩＡ－ＲＳ－４２３Ａ、ＥＩＡ－ＲＳ－４４９、ＥＩＡ－ＲＳ－４８５、ＡＲ－ＩＮＣ－４２９等。     

C／O测井响应随源距变化的理论研究

针对井内介质分别为水、油，地层分别为３５％孔隙度饱和水砂和油砂的４种情况，采用蒙特卡罗方法模拟外径φ８９碳氧比测井仪不同源距处的非弹性散射伽马能谱。通过分析地层或井内介质不同时的Ｃ／Ｏ差值随源距变化的关系，为设计仪器推荐源距参数。     

多传感器目标识别的图像数据融合技术研究

军事和空间技术的要求促进了微光技术的发展。微光图像实时处理技术是夜技术今后发展的重要方向，本文针对微光图像与脉冲激光测距仪的数据信息实时融合与显示的方法及其实现进行了研究。给出了系统框图及工作原理，为实现探测识别、跟踪的实时性、智能化和微型化，从而为研制新一代战术侦察与火控系统提供了具体有效的技术基础。