Fast Voronoi modeling

The common way to construct Voronoi tessellations is to compare the distances between given reference points using a given distance function. To generalize this distance-function concept we expand an existing approach which defines distance functions by their ``unit circles'. Our new approach allows modeling the ``unit circles' by a closed Spline curve. Changing the control polygon directly affects the tessellation's appearance. Typically generalized Voronoi diagrams are represented by Voronoi vertices and curves separating the individual tiles. To obtain interactive modeling we extended an existing hardware accelerated rendering approach computing a bitmap-representation using different colors for individual tiles. With our extension, we are able to use our Spline distance representations as input for a growing process. This growing process easily takes into account weighting approaches like multiplicative, additive, and even free functional weighting.     

半导体浪涌保护器基区参数探讨

讨论了半导体浪涌保护器件的基区宽度，着重分析了基区宽度与开通电压、静电电容、浪涌能力的关系，指出控制基区宽度，可有效地提高器件的浪涌能力，降低静电电容和开通电压     

一种带接口的CMOS10位电流型乘法D／A转换器

介绍了一种带接口的单片ＣＭＯＳ１０位电流型乘法Ｄ／Ａ转换器的设计及工作方式。着重阐述逻辑电平转换、控制逻辑的结构设计及其工作方式。在不修调电阻网络的情况下，该Ｄ／Ａ转换器在５Ｖ、１５Ｖ下，其线性误差、微分误差、满刻度误差均能达到１０位精度     

基于H.261的可变速率图像记录系统的实现

提出了一种基于H．261标准的输出码流速率可变的图像编码控制方法，编码器根据输出缓冲区充满度控制量化参数，同时依据图像数据量大小自动选择合适的输出码流速率，详细给出了一个图像记录系统的工程实现方案，测试结果表明，应用这一方法可在保证图像质量的前提下有效地降低图像记录数据量。     

Evaluation of effect of hydrogen on toughness of Zircaloy-2 by instrumented drop weight impact testing

Hydride-assisted degradation in fracture toughness of Zircaloy-2 was evaluated by carrying out instrumented drop-weight tests on curved Charpy specimens fabricated from virgin pressure tube. Samples were charged to 60 ppm and 225 ppm hydrogen. Ductile-to-brittle-transition behaviour was exhibited by as-received and hydrided samples. The onset of ductile-to-brittle-transition was at about 130 °C for hydrided samples, irrespective of their hydrogen content. Dynamic fracture toughness (K_ID) was estimated based on linear elastic fracture mechanics (LEFM) approach. For fractures occurring after general yielding, the fracture toughness was derived based on equivalent energy criterion. Results are supplemented with fractography. This simple procedure of impact testing appears to be promising for monitoring service-induced degradation in fracture toughness of pressure tubes.     

型钢厂试轧美标H型钢性能分析研究

分析了型钢厂试制热轧美标H型钢低温冲击韧性偏低的原因，并在此基础上提出了对生产工艺的优化与改进。     

The distribution of anthocyanins in grape skin extracts of port wine cultivars as determined by high performance liquid chromatography

The distribution of anthocyanins in methanolic skin extracts of 16 grape cultivars used for port wine production and grown at five sites in the Douro Valley in Northern Portugal has been assessed by high performance liquid chromatography. Results are confined to the seven most readily separated and identified anthocyanins and are expressed as percentages of their total (88–99% of the total integrated area). Anthocyanins based on malvidin (Mv) predominated. Of these, Mv 3-glucoside was the major pigment (33–60%), being exceeded by Mv 3-p-coumarylglucoside (2–51%) in only two cultivars; Mv 3-acetylglucoside (1–15%) was consistently the lowest. Peonidin 3-glucoside (1–27%) was prominent in four cultivars, but delphinidin 3-glucoside (1–11%), petunidin 3-glucoside (2–11%) and cyanidin 3-glucoside (trace-6%) were of low proportions throughout. The ratio Mv 3-acetylglucoside/total Mv glucosides appeared characteristic of cultivar, independent of site, and a useful aid to identification of grape cultivars. The coloured pulp of some cultivars contained peonidin 3-glucoside as a major component, present in greater proportions than in the skin; the percentage of Mv 3-p-coumarylglucoside was lower in pulp than in skin. The identities of six of the seven anthocyanins were confirmed by fast atom bombardment mass spectrometry and the structures of the Mv derivatives were determined by nuclear magnetic resonance. The formation of formyl and acetyl anthocyanin artefacts is described.     

河套盆地晚更新世以来黄河改道对高砷地下水分布的控制机制

针对河套盆地开展了历时多年的水文地质环境地质调查,利用采集的298组浅层地下水样品以及收集并甄选的382个水文地质钻孔记录分析发现:河套盆地内95%的高砷地下水(As质量浓度10μg/L)集中在黄河决口、改道形成的古河道影响带及黄河决口扇裙带。其中,盆地南部首次发现了较为集中的高砷地下水,其分布范围与黄河北岸的晚更新世以来黄河决口、改道形成的4个大型决口扇,在空间上有着良好的对应关系。黄河古河道带及决口扇裙带表现为较强的还原环境及蒸发浓缩作用以及较弱的地表水补给强度。受pH值、含铁氧化物的还原性溶解等因素影响,决口扇裙带浅层地下水中砷的含量略低于平原中部黄河古河道带。结果表明:黄河古河道带及决口扇裙带特定的沉积环境控制着地下水的水文地球化学过程,进而对高砷地下水的分布具有决定性的作用。     

基于SOPC的网络视频监控系统的设计

提出一种以Nios Ⅱ软核处理器为核心,利用SOPC技术构建硬件平台,采用H.263协议压缩视频数据的网络视频监控系统设计方案;详细分析了系统的功能需求,确定了系统设计的总体方案;按照模块化的思想,设计了各个功能模块,并给出了网络芯片DM9000A电路的具体实现,利用μClinux中的TCP/IP协议栈进行数据通信,分析H.263视频编码协议基本原理,提出在硬件上实现H.263协议的设计方法;实验结果显示系统的网络视频传输速率达到25～30fps,满足实时性的要求.本设计方法灵活、成本较低、易扩展,具有一定的实用价值.