A Modified Variational-Gradient Method for Quasilinear Equations

A modified variational-gradient method is proposed and substantiated for quasilinear operator equations in a Hilbert space.     

Fabrication of Strain-Relaxed Si<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Ge<Subscript>x</Subscript>/Si(001) Buffer Layers of Low Surface Roughness

The results are presented of the fabrication of strain-relaxed graded Si_{1 − x} Ge_x/Si(001) buffer layers with a maximum Ge fraction of about 0.25 that have a low density of threading dislocations (<10⁶ cm⁻²) and low surface roughness. The buffer layers are grown by atmospheric-pressure hydride CVD. It is found that chemical mechanical polishing can reduce their surface roughness to a level comparable with that of the original Si(001) substrates. It is shown that the polished buffer layers can serve as substrates for MBE-grown SiGe/Si heterostructures.__________Translated from Mikroelektronika, Vol. 34, No. 4, 2005, pp. 243–250.Original Russian Text Copyright © 2005 by Vostokov, Drozdov, Krasil’nik, Kuznetsov, Novikov, Perevoshchikov, Shaleev.     

Etching behavior of CVD zinc selenide in inorganic acid solutions

Chemical interaction between polished surfaces of polycrystalline zinc selenide and inorganic acid solutions of various concentrations has been studied.     

Model of Primary Austenite Dendrite Structure in Hypoeutectic Cast Iron

Ｉｔｗａｓｒｅｐｏｒｔｅｄ[1] ｔｈａｔｔｈｅｍｉｃｒｏ ｓｔｅｒｅｏｓｔｒｕｃｔｕｒｅｏｆｐｒｉｍａｒｙａｕｓｔｅｎｉｔｅｉｎｃａｓｔｉｒｏｎｃｏｎｓｉｓｔｓｏｆｐｒｉｍａｒｙｓｔｅｍｓａｎｄｓｅｃｏｎｄａｒｙａｒｍｓｔｈａｔ ｇｒｏｗａｃｃｏｒｄｉｎｇｔｏｄｅｎｄｒｉｔｅｃｒｙｓｔａｌｓｂｒａｎｃｈｒｕｌｅ ,ａｎｄｓｏｍｅｏｆｐｒｉｍａｒｙａｕｓｔｅｎｉｔｅｅｖｅｎｈａｖｅｔｈｉｒｄａｒｍｓ .ＭｉｙａｋｅＨｅｔａｌ[2 ]ｐｒｏｐｏｓｅｄａｃｏｎｃｅｐｔｏｆｒｅｇｉｏｎｍｏｄｅｌｂｙｓｔｕｄｙｉｎｇ…     

Mechanism of the skeletal isomerisation of linear butenes over ferrierite: analysis of side reactions

An investigation of the effect of reaction conditions on product distribution in the skeletal isomerisation reaction of linear butenes has been carried out. The main reaction routes over ferrierite have been identified. Beside the main product isobutene, major by-product formation occurs. The unwanted reactions include dimerisation of butene to form octenes, hydrogen transfer yielding small amounts of saturated C₃ and C₄ hydrocarbons and disproportionation producing propene and pentenes. The most abundant by-products were pentene and propene, though these were not formed in equimolar amounts as could be expected. Oligomerisation experiments of propene over ferrierite produced large amounts of butene and pentene, revealing the presence of adsorbed nonene. The cracking of this surface species to hexene and propene is the most likely reaction route for the excess propene formation. This additional path to propene formation operates mainly at temperatures above 623 K.     

Ozonation of CI Reactive Black 5 using rotating packed bed and stirred tank reactor

This study investigates the ozonation of CI Reactive Black 5 (RB5) by using the rotating packed bed (RPB) and completely stirred tank reactor (CSTR) as ozone contactors. The RPB, which provides high gravitational force by adjusting the rotational speed, was employed as a novel ozone contactor. The same ozone dosage was separately introduced into either the RPB or the CSTR for the investigation, while the experimental solution was continuously circulated within the apparatus consisting of the RPB and CSTR. The decolorization and mineralization efficiencies of RB5 in the course of ozonation are compared for these two methods. Moreover, the dissolved and off‐gas ozone concentrations were simultaneously monitored for the further analysis. As a result, the ozone mass transfer rate per unit volume of the RPB was significantly higher because of its higher mass transfer coefficient and gas–liquid concentration driving force. Furthermore, ozonation kinetics was found to be independent of the gravitational magnitude of an ozone gas–liquid contactor. Therefore, the results suggest employing RPBs as ozone‐contacting devices with the advantage of volume reduction. The experimental results, which can be used for further modeling of the ozonation process in the RPB, also show the requirement of correct design for the RPB. Consequently, the present study is useful for the understanding of practical application of RPBs. Copyright © 2004 Society of Chemical Industry     

MPEG-2视频编码标准及CLM4400视频编码芯片简介

本文通过MPEG-2和MPEG-1在视频方面的比较，简略地介绍了MPEG-2视频标准，并附带介绍了C-CUBE公司的MPEG-2视频编码芯片CLM4400的功能和应用前景。     

激光平网雕刻机设计

研制了用于制作平面网版的激光雕刻机，设计了雕刻机用CO2激光器、光路系统及单片机控制系统，探讨了将图像文件转化为控制命令文件的方法。