Probabilistic linear models for multiresolution estimation in gray-level images

A multiresolution analysis of digital gray-level images is presented. A gray-level multi-scale framework is determined from two main assumptions: the gray scale is binary at the finest spatial resolution, and the gray levels of composed regions are obtained additively. In order to interrelate the gray-level histograms of the same image at different resolutions, probabilistic linear models are developed, which are then applied for estimation. Linear-optimization theory is used as a way of constructing such models. A general procedure for image processing is sketched, based on gray-level estimation. A versatile algorithm for nonlinear filtering is derived. Some examples of prospective applications are given.This work was partially supported by grant TIC91-646 from the DGYCIT of the Spanish Government.     

无源微波遥感用于地震预报的实验研究

对无源微波遥感用于地震预报在理论研究的基础上对不同岩性不同结构的岩石试件进行了加载实验，测量了岩石试件的微波辐射随载荷的变化．实验得出：岩石试件的微波辐射能量随岩石应力状态变化而显著变化；而且，不同的波段变化的幅度不同；同一波段不同极化方式的波随应力变化的变化量也不同；微波辐射能量的变化能够被卫星微波遥感探测器探测到．实验还发现，岩石试件临破裂前出现明显的微波辐射异常．     

多层多跨铰接框架计算

本文采用柔度矩阵法,对多层多跨铰接框架进行静力与动力分析,附有实例。与刚度法相比,其优点是使矩阵降价,方法实用,可应用于工业厂房和一般刚架设计中。     

核电厂放射性监测系统仿真的数学物理模型

较详细地介绍了在北京核电厂模拟培训中心的模拟器上建立ＲＭＳ仿真系统的工作。首先对仿真的原型进行分析和简化，建立数学物理模型，并对包括ＲＣＳ、ＰＺＲ、ＳＧ、ＣＶＣＳ等的近２０个核电厂系统进行了动态仿真建模，确定ＲＭＳ各监测点放射性水平仿真读数的计算方法，最后，给出部分仿真实验结果，以验证数学物理模型的可靠性和适用性。     

Early detection of ageing in solder joints through laser probe thermal analysis of the peltier effect

We have recently developed an optical contactless method for testing the quality of solder joints during accelerated thermal cycling ageing processes.¹ The method was based upon the measurement of the dynamic thermal behaviour of the joint to short bursts of Joule heating. It has proved to be efficient in revealing the formation of cracks at the lead-solder interface. We present a method to evaluate ageing at a much earlier stage in the cycling process. We have observed in earlier work,¹ that before cracks appear, structural changes occur in the solder at the lead-solder interface. The thermal response of the solder joint is recorded over time to a Peltier heat perturbation produced by flowing a current pulse through the interface where structural changes occur. The key point in this method is to discriminate the Peltier effect from the Joule thermal response because both effects generate heat. The variation of the early Peltier response in the thermal cycling ageing tests is seen as a quantitative signature of the structural changes in the lead-solder interface.     

光纤传感器在海洋环境监测中的应用

海洋是个特殊的环境,为许多光纤传感器提供了一个极好的应用领域。对于海洋这个特殊的“敌对”环境,光纤传感器将面临许多挑战。 本文着重介绍应用于海水温度、浊度、盐份浓度、浮游生物和溶解物光吸收量以及环境湿度等海洋环境参数监测的光纤传感器的原理、结构和特性,展望光纤传感器在海洋环境监测方面的美好前景。     

用线性状态观测器重构交流矢量控制系统中的负载扰动

在异步电动机磁场定向数学模型的基础上,给出了恒磁条件下异步电动机的解耦模型及传动系统的线性状态方程,并提出了重构负载扰动转矩的线性状态观测器。利用重构的负载转矩在矢量控制系统中进行扰动前馈,明显地提高了系统的抗负载扰动能力,从而为进一步提高矢量控制系统的动态性能开辟了一条有效的途径。     

铝合金铁相团球化熔剂的研制

研制了一种铝合金铁相团球化熔剂，在含铁量较高（１．０％－４．０％Ｆｅ）的铝合金中加入该熔剂后，可使针片状的铁相变为团球状或颗粒状组织。从而大幅度提高原合金的机械性能，δｂ和δ分别提高２０％－９０％和４０％－１００％。生产实验表明：该熔剂团球化效果好（具有长效性），极便于在生产中推广应用。     

深井重泥浆弱凝胶工艺技术初探

重泥浆强凝胶体系对钴井会产生不利影响。笔者结合川东地区的实际情况,分析了重泥浆强凝胶形成的原因和重泥浆弱凝胶的形成机制,提出了形成重泥浆弱凝胶体系的核心和设计原则,总结出了一套以正确使用泥浆添加剂并配合强有力的固控措施为主的成套深井重泥浆弱凝胶工艺技术,介绍了这套技术在川东地区的应用情况。实践证明,少用甚至不用泥浆降粘剂就可获得并维持尽可能低的静切力,使τ_s,10s为0.5—6Pα、τ_s,10min为2—12.5Pα。