Heat flux profile of the furnace wall of a 300 MWe CFB boiler

It is important to properly understand and calculate the distributions of the heat flux and the heat transfer coefficient in a furnace for designing a circulating fluidized bed (CFB) boiler, especially for one with supercritical parameters. An experimental study of the heat transfer in a commercial 300 MWe CFB boiler was conducted in this work. The heat flux from the bed to the waterwall was measured by a heat flux meter at four different heights. The influence of suspension density and bed temperature was analyzed by measuring the pressure profile and temperature profile in the furnace. In addition a numerical modeling study on the two phase flow in the furnace was carried out. The results indicate that the density of the solids suspension was non-uniform in the cross section at a certain height, and decreased gradually with increasing furnace height. Consequently, the distribution of heat flux in the horizontal plane was non-uniform and decreased along the height of the furnace. The heat flux showed a decreasing trend near the center.     

First successful fabrication of high-performance all-refractory-metal (Ta-Au) GaAs FET using very highly doped N+-layers and nonalloyed ohmic contacts

An all-refractory-metal GaAs MESFET (ARFET) making use of a Ta Schottky barrier with a thick gold overlayer for the source, gate and drain, and very highly doped N+-layers (2x1019 cm-3) to achieve low-resistivity nonalloyed ohmic contacts, has been successfully fabricated. These have a 400 ?m gate periphery and 0.6 ?m gate length and measured an associated gain of 10.22 dB and a noise figure of 2.14 dB at 8 GHz. The ARFETs were fabricated on epitaxial layers grown by MBE. Only one mask was used to simultaneously define source, gate and drain regions via a plasma dry-etch technique.     

用于煤浆系统研究的光子输运程序及其实验标定

本文介绍了为进行煤浆系统光子输运研究而专门设计的Ｍｏｎｔｅ Ｃａｒｌｏ程序Ｍｃｐｈｏｔ，采用实验方法对该程序进行了标定，实验结果和计算结果符合得很好。     

面向目标控制照明的合成波源偏移

应用Fourier有限差分算子，研究目标控制照明的合成波源偏移成像。平面波源与小束波源这些合成波源在目标控制照明下的偏移，都是通过增强对目标区域的有效照明来改善成像质量，通过减少非目标区域的计算冗余来提高计算效率。由分析和应用合成平面波源偏移和控制照明技术扩展开去，综合考虑平面波源和小束波源的合成与偏移，并通过有效照射合成波源的概念，分析合成波源的有利照明，进行面向目标区域的控制照明和合成波源偏移。最后，对具有速度强横向变化和陡倾角反射的复杂2D盐丘模型数据，做了相应的合成波源偏移数值试验。     

Lipase-catalysed acidolysis of lard with caprylic acid to produce structured lipid

Enzymatic acidolysis of lard with caprylic acid was investigated. Of the five lipases that were tested in the initial screening, immobilised lipase TL IM from Thermomyces lanuginosus resulted in the highest incorporation of caprylic acid into lard. This enzyme was further studied for the effect of enzyme load, organic solvent, substrate ratio, reaction time and temperature. HPLC was used to analyse the products from the acidolysis reaction. The highest incorporation was attained at 15% enzyme load. Among the solvents tested, n‐hexane was the best reaction medium for the acidolysis of lard with caprylic acid. Time course studied suggests that the incorporation of caprylic acid into lard was increased up to 37.7 mol% after 24 h. Desirable mole ratio of lard to caprylic acid was 1:2, caprylic acid incorporation up to 34.2 mol%. Temperature had no significant effect on enzyme activity in the range of 40–80 °C.     

机械CAD软件系统面向对象建模方法研究

以面向对象的减速器ＣＡＤ系统的分析建模为例，对机械ＣＡＤ系统采用面得对象技术建模的方法进行了研究，总结出此类ＣＡＤ系统面向对象建模的一般特点。     

一个具扩散的捕食模型非常数正解的存在性

考虑一个Neumann边界条件下具扩散和Holling型功能反应的捕食一被捕食模型的平衡态问题，获得了该模型正平衡态解的一些结果．首先，给出了正解的先验估计，进而，用能量方法得到其非常数正解的不存在性，用拓扑度理论得出其非常数正解的存在性结果．     

基坑深层水平位移的监测方法比选

围护结构深层水平位移监测俗称测斜,是深基坑监测的一项重要内容。本文首先介绍了测斜的工作原理,然后结合工程实例介绍了“半米双向”、“一米双向”、“半米单向”和“一米单向”4种不同的测斜方法,并对其监测结果和优缺点进行了对比分析,有助于根据不同基坑的实际情况选择最佳的监测方法,从而可以经济合理地完成监测任务,对类似工程具有借鉴意义。     

对主流自适应码率流媒体技术的分析

伴随着互联网多媒体应用的快速增长,尤其是在线视频业务的不断发展,传统的流媒体技术由于其单一的编码方式难以适应差异化的用户网络变化,极大地影响了用户体验。分析了当前在线视频业务面临的主要问题,同时介绍了新兴的自适应码率流媒体技术的特点和优势。通过对主流自适应码率流媒体和传统流媒体技术的分析和比较,表明对于OTT业务而言,标准化的自适应码率流媒体技术比传统的流媒体技术更加有优势。