The Method of Dynamic Palette Construction in Realistic Visualization Systems

The paper describes the colour approximation problem and the method of dynamic palette construction is suggested for its solution. The method uses the graphic display palette based on the computed true colour of the individual picture. Some aspects of human colour perception are considered. Two metrics in colour space are introduced to estimate closeness of the suggested colour approximation. The method was applied to visualize 3D scenes generated by ray tracing.     

钢管在线测厚和应用

钢管在线测厚是近年发展较快的一项高科技技术，该设备对生产高质量的无缝钢管具有较大帮助。叙述了钢管在线测厚的基本原理和在宝钢钢管分公司张减机上使用的实绩。     

煤矿管道瓦斯流量计量技术研究

阐述了煤矿管道瓦斯流量计量技术的发展现状,分析了孔板流量计、涡街流量计、皮托管流量计、旋进漩涡流量计、V锥流量计的优缺点;针对瓦斯流量测量准确度受气体中的杂质和瓦斯体积分数变化影响的问题,提出了解决办法;建议煤矿瓦斯抽放管网中的主管、干管、支管采用V锥流量计,汇流管以及各评价单元采用多点采样的插入式流量计;指出煤矿管道瓦斯流量计量应根据不同的现场状况、工况条件及测量需求选择相应的流量计。     

基于MCS-51系列单片机时间控制器软件的设计与实现

本文设计的基于MCS-51系列单片机时间控制器主要应用AT89C51作为控制核心,采用实时时钟芯片DSl302、EipROM24C02及动态数码显示相结合。具有硬件电路简单、软件功能完善、控制系统可靠、性价比较高等特点,具有一定的使用和参考价值。     

用LG55冷轧管机轧制小直径不锈钢管孔型改进

介绍了ＬＧ５５冷轧管机使用Φ７～３２ｍｍ、Φ５０～３２ｍｍ孔型轧制小直径不锈钢管的工艺特点。试验表明，两种孔型可行，且Φ５７～３２ｍｍ孔型的综合使用效果更好。     

Development of the meshless finite volume particle method with exact and efficient calculation of interparticle area

The Finite Volume Particle Method (FVPM) is a meshless method based on a definition of interparticle area which is closely analogous to cell face area in the classical finite volume method. In previous work, the interparticle area has been computed by numerical integration, which is a source of error and is extremely expensive. We show that if the particle weight or kernel function is defined as a discontinuous top-hat function, the particle interaction vectors may be evaluated exactly and efficiently. The new formulation reduces overall computational time by a factor between 6.4 and 8.2. In numerical experiments on a viscous flow with an analytical solution, the method converges under all conditions. Significantly, in contrast with standard FVPM and SPH, error depends on particle size but not on particle overlap (as long as the computational domain is completely covered by particles). The new method is shown to be superior to standard FVPM for shock tube flow and inviscid steady transonic flow. In benchmarking on a viscous multiphase flow application, FVPM with exact interparticle area is shown to be competitive with a mesh-based volume-of-fluid solver in terms of computational time required to resolve the structure of an interface.     

Development of high‐definition aqueous polyvinylpyrrolidone photoresists for cathode ray tubes

Aqueous photoresists that are capable of higher resolutions than are currently employed by the cathode ray tube (CRT) industry were developed by combining photoactivators, which activate at shorter UV wavelengths with polyvinylpyrrolidone (PVP). Two photoactivators were synthesized: 4,4′‐diazido‐2,2′‐biphenyl disodium disulfonate (DABP), which has a maximum absorbance at 264 nm, and 4,4′‐diazido‐2,2′‐biphenylethane disodium disulfonate (DABPE), which has a maximum absorbance at 258 nm. The PVP/DABP and PVP/DABPE photoresists successfully imaged a pattern with resolution as small as 4.4 μm with photoactivator concentrations greater than 20% of the PVP concentration. Addition of silane and emulgen greatly improved the performance of the photoresists with more uniform coatings of thicknesses of up to 1.4 μm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1637–1644, 2006     

换热器管板厚度的快速计算

在化工生产中，换热器设备是应用最广泛的一种设备，且占主导地位。而在换热器设计过程中，管板厚度设计计算比较复杂。本文的特点是在满足GB151—1999《管壳式换热器》标准要求的前提下，介绍一种快速简便估算管板厚度的计算公式，从而达到快速确定管板厚度的目的。     

Scalable Realistic Rendering with Many‐Light Methods

Recent years have seen increasing attention and significant progress in many‐light rendering, a class of methods for efficient computation of global illumination. The many‐light formulation offers a unified mathematical framework for the problem reducing the full lighting transport simulation to the calculation of the direct illumination from many virtual light sources. These methods are unrivaled in their scalability: they are able to produce plausible images in a fraction of a second but also converge to the full solution over time. In this state‐of‐the‐art report, we give an easy‐to‐follow, introductory tutorial of the many‐light theory; provide a comprehensive, unified survey of the topic with a comparison of the main algorithms; discuss limitations regarding materials and light transport phenomena and present a vision to motivate and guide future research. We will cover both the fundamental concepts as well as improvements, extensions and applications of many‐light rendering.