High stress abrasive wear behavior of sillimanite-reinforced Al-alloy matrix composite: A factorial design approach

An attempt has been made to explore the possibility of using a natural mineral, namely sillimanite, as dispersoid for synthesizing aluminum alloy composite by solidification technique. The abrasive wear behavior of this composite has been studied through factorial design of experiments. The wear behavior of the composite (Y _composite) and the alloy (Y _alloy) is expressed in terms of the coded values of different experimental parameters like applied load (x ₁), abrasive size (x ₂), and sliding distance (x ₃) by the following linear regression equations:

提高"两课"教师素质推进高校素质教育

"两课"教育是思想政治教育的主渠道,在高校的素质教育中具有不可代替的作用."两课"教师是实施素质教育的主体力量,因此,要推进高校素质教育, 从政治、业务、创新、人格等多方面提高"两课"教师的素质刻不容缓.     

应用变速成图技术解释富台油田砂砾岩体构造

用常规速度量版进行地震时深转换,已无法满足高精度构造分析的需要。在分析胜利油区富台油田隐蔽油气藏地球物理特征的基础上,应用变速成图技术对各解释层进行变速时深转换,解决了由于砂砾岩体“速度陷阱”造成构造深度误差问题,提高了构造解释的精度,为勘探目标研究和申报储量奠定了基础。图2表1参6     

液-液分离旋流器结构选型计算

在前期对液-液旋流分离器流量压降特性实验研究的基础上,分析了结构参数、操作参数及物性参数对液-液旋流分离效率的影响;提出了液-液旋流分离器结构设计的设计方法和设计步骤,认为建立性能优良的旋流器模型数据库,是选型设计的基础和前提。     

与时俱进求实创新--大连理工大学科技楼建筑设计的思考

通过对大连理工大学科技楼设计的简述,分析了现代办公建筑的新型设计理念,考察了城市建筑发展总体趋势和基地所在区域内建筑环境氛围,并在此基础上提出了“与时俱进,求实创新”的总体设计理念,并以相应手法贯穿整个设计环节。     

国际机场石方供料峒室控制大爆破

根据机场对填方石料粒径的严格要求及石料场周围的复杂环境。我司技术人员根据多年,多次硐室大爆破成功的经验,从导洞布置方面严格要求各药室最小抵抗线均一化,从药包布置、药量分布、装药结构、起爆顺序等方面作了许多科学改进,精心设计,严密施工。终于使大爆破获得圆满成功。     

双电压合成矩阵变换器特性与电压扇区的关系分析

在双电压合成矩阵变换器中,需要将每个周期内的输入、输出电压划分成若干扇区。根据不同的划分方法,扇区的形状可以是S形或X形。首先对双电压合成方程的一般形式占空比的计算方法进行了改进。然后研究了输入、输出电压扇区形状的四种组合即{X,X}、{X,S}、{S,X}、{S,S}。针对每一种组合研究了矩阵变换器特性与相应扇区组合的关系。这些特性包括“原点开关”的存在性、最大电压增益及输入电流波形。通过分析比较得出,最佳输入、输出电压扇区组合是{S,X}。这种组合存在“原点开关”。便于实现,能够同时获得最大的电压增益和对称的正弦输入电流,功率因数可以达到1。通过仿真分析验证了结论的正确性。     

站在语言信息处理基础研究的前沿--"973"相关课题介绍

本文扼要介绍了国家重点基础研究发展规划项目"973"项目中与语言信息处理领域相关的课题"面向大规模真实文本的汉语计算理论、方法和工具"的基本情况;讨论了该课题的主要研究目标、研究内容及具体实施方案;向读者显示了该课题的若干最新进展,并指出了标准(规范)问题在语言工程中的重要性.     

BUTYL ACETATE AND YEASTS INTERACT IN ADHESION AND GERMINATION OF Botrytis cinerea CONIDIA IN VITRO AND IN FUNGAL DECAY OF GOLDEN DELICIOUS APPLE

Butyl acetate is a volatile aroma and flavor compound in apple. Conidia of three strains of Botrytis cinerea, a fungus that causes decay of apple fruit in postharvest storage, had greater adhesion to and greater germination on polycarbonate membrane filters on water inside sealed 500 cc glass jars that were injected with 4 l butyl acetate than conidia not so exposed. Conidial germination was highly correlated with conidial adhesion. The yeasts Sporobolomyces roseus and Cryptococcus laurentii, but not Saccharomyces cerevisiae, reduced the adhesion and germination promoting effect of butyl acetate. Conidia did not readily utilize butyl acetate as a food source, as shown by lack of tetrazolium violet reduction, whereas S. roseus and C. laurentii, but not S. cerevisiae did. Butyl acetate added to suspensions of conidia increased the electrical conductivity of the suspensions and increased the loss of ¹⁴C from ¹⁴C-labeled conidia compared to conidia unexposed to butyl acetate. Uptake of [¹⁴C]glucose by conidia was not increased by butyl acetate. Wounds of Golden Delicious apples inoculated with conidia (strain F-J-4) in a dilute solution of butyl acetate had greater decay than unexposed wounds. S. roseus and C. laurentii, but not S. cerevisiae, added with the conidia decreased the incidence or size of decay. Results indicated that butyl acetate increased conidial adhesion, stimulating conidial germination, and some yeasts can reduce this effect.     

适合使用压边圈的临界计算及数值模拟

在复杂的板料成形过程中,研究压边圈的规律尤其重要.以圆筒形零件为例,通过能量法给出压边圈防皱的理论依据,据此理论依据使用压边圈在板料成形过程中防皱.通过数值模拟软件Dynaform,对具体板料成形过程进行验证,得到与理论值相符的模拟结果,从而验证了理论公式的正确性.