Rendering of Surface and Volume Details in Volume Data*

Aiming at the detail rendering in volume data, a new volume illumination model, called Composed Scattering Model (CSM), is presented. In order to enhance different details in volume data, scattering intensity is decomposed into volume scattering intensity and surface scattering intensity with different weight functions. According to the Gauss probability distribution of gray and gradient of data, we propose an accurate method to detect the materials in a voxel, called composed segmentation. In addition, we discuss the principle of constructing these weight functions based on the operators defined in composed segmentation. CSM can generate images containing more details than most popular volume rendering models. This model has been applied to the direct volume rendering of 3D data sets obtained by CT and MRI. The resultant images show not only rich details but also clear boundary surfaces. CSM is demonstrated as an accurate volume rendering model suited for detail enhancement in volume data sets.     

奇异摄动系统主导极点配置的一种方法

本文将奇异摄动系统看成是存在参数扰动的广义系统的一种特殊形式，然后利用广义系统特征结构配置来使广义系统的有限闭环极点尽可能接近奇异摄动系统的闭环主导极点，从而达到近似配置奇异摄动系统主导极点的目的。本文提供的算法是数值稳定的。     

核壳型铁钴纳米复合材料的制备及其性能

采用多元醇还原工艺和自组装技术,在微米级Fe粉表面包覆纳米Co粒子,一步法制备了一种具有核壳结构的复合磁性微球,用SEM表征了其相组成和形貌,用VSM测试了磁滞回线,初步研究了磁学性能。结果表明:用该法制备的核壳型Fe/Co纳米复合材料表面包覆致密,其比饱和磁化强度和矫顽力介于微米铁粉和纳米钴粉之间。     

YC6112柴油机主轴烧瓦故障分析

根据玉柴6112机型连续出现主轴烧瓦故障，本文阐述的失效的机理及原因，通过计算提出了行之有效的改正方法。     

蒸发式空冷器的运行实践

通过了解蒸发式空冷器的工作原理和结构,在运行实践过程中,对组成设备出现的问题提出相应的解决方案,并对部分组成设备提出改进的建议,以方便检修和维护,并提出了在冬季长时间高炉休风情况下保证水温不下降过低的解决方案。     

海水注入开发中剩余油饱和度评价研究

剩余油饱和度评价是油田水淹层测井评价中的重点和难点。当油田发生水淹后,储层的润湿性、地层水电阻率都将发生较大的变化,因此剩余油饱和度评价所需的处理参数必须重新确定。以南中国海某河流相沉积油田的储层在水淹后的剩余油饱和度评价中的关键参数研究为例,通过模拟油藏条件下的岩电实验和地层混合水矿化度与实际含水率的关系,研究探索求取剩余油饱和度评价关键参数的有效方法,应用中与实际生产符合较好,为此类开发油田的剩余油饱和度的精确评价奠定了基础。     

浅谈气泡混合轻质土的特点及应用

结合高速公路的发展,分析了气泡混合轻质土的设计机理,详细地介绍了气泡混合轻质土的工程特性,阐述了气泡混合轻质土在公路建设中的应用,最后对气泡混合轻质土的应用前景进行了展望。     

部分可渗透直立圆柱的消波作用研究

本文导出了线性波浪作用于上部可渗透的直立刚性圆柱体上的水动力的解析解。在线性有势流的假定下，用特征函数展开方法求出了内部和外部流场的解。给出了不同波浪要素及结构尺寸参数下的数值结果。由结果可知，提高可渗透性可以有效消减波幅。     

Evaluation of Morphology—Stable Critical Size of KNbO3 Crystals

Skeletal form of KnbO3 crystals growing in Li2B4O7 solvent was in-situ observed at 900℃ and it was found that shallow depression started to develop on the surface of KnbO3 crystals when the crystal size exceeded several micron,typically 7 micron.Based on the quantitative criterion derived by Chernov,the estimated critical size of KNbO3 crystals was 1 micron,which was consistent with the experimental measurement.The kinetic coefficients,Kcorner and Kcr,in the criterion were experimentally obtained in the diffusive-convective and diffusive-advective flow states respectively.     

活化铁矿粉技术及其效果评价

随勘探技术发展,高压超高压油气井日益增多,高密度、超高密度钻井液使用也越来越多.室内为配制密度大干2.4 g/cm3的超高密度钻井液,采用铁矿粉作为加重剂,并通过表面活化的原理对铁矿粉进行表面处理,以提高钻井液的固相容纳能力.该活化工艺借鉴了国内外相关产品的技术特点,以优选的表面活性剂为主要活化材料,并添加了无机盐和硅酸盐作为助吸附材料,提高了活化效果.室内实验表明,用活化铁矿粉加重的钻井液体系能保持良好的流变性和悬浮能力,能保证钻进时的正常循环,并且摩阻系数也低于常规铁矿粉加重钻井液.