Al-Si合金中初晶Si的台阶生长

采用离心倾液法研究过共晶Ａｌ－Ｓｉ合金初晶Ｓｉ的生长形貌时发现，初晶Ｓｉ存在生长台阶，台阶的高度为数十至数百微米，从初晶Ｓｉ根部至尖端，台阶的高度逐渐变小，初晶Ｓｉ存在位错台阶生长机制．这一生长机制能够形成棱柱体或棱锥体、八面体和球形初晶Ｓｉ，以及产生初晶Ｓｉ的分枝和形成初晶Ｓｉ的生长迹线．     

Scalable group management in large-scale virtualized clusters

To save cost,more and more users choose provision resources at the granularity of virtual machines in cluster systems,especially data centres.Maintaining a consistent member view is the foundation of reliable cluster managements,and it also raises several challenge issues for large scale cluster systems deployed with virtual machines (which we call virtualized clusters).In this paper,we introduce our experience in design and implementation of scalable member view management on large-scale virtual clusters.Our research contributions include three-aspects:1 ) we propose a scalable and reliable management infrastructure that combines a peer-to-peer structure and a hierarchy structure to maintain a consistent member view in virtual clusters; 2) we present a light-weighted group membership algorithm that can reach the consistent member view within a single round of message exchange; 3 ) we design and implement a scalable membership service that can provide virtual machines and maintain a consistent member view in virtual clusters.Our work is verified on Dawning 5000A,which ranked No.10 of Top 500 super computers in November,2008.     

MATLAB图形处理在电类课程领域中的应用

主要介绍了MATLAB图形功能在信号产生、动态电路分析、模拟调制和自动控制领域的典型应用开发,扩大了MATLAB在相关领域的影响。     

大直径泥水盾构带压进仓地层加固及保压技术

通过对北京铁路地下直径线带压进仓换刀工程实例的分析，探讨了注浆加固及桩基加固在地层加固中的应用，分析了带压进仓的漏气原因并采取相应的应对措施，保证了盾构的正常施工。     

基于CAN总线嵌入式数控系统的研究

基于ARM9和MCX314AL为核心的嵌入式数控硬件平台，采用专用CAN总线局域网收发器，设计了一种新型局域网嵌入式数控系统。详细介绍了嵌入式局域网数控系统的结构和功能，并对数控系统软件进行了研究。     

单片机监控的VHF-FM二单元天线接收系统

在原有的中小规模集成电路两支路监测选择系统基础上,综合考虑了如何减少体积,提高性能价格比,给出了一种新型的单片机监控的VHF—FM二单元天线接收系统的软硬件设计结果.该系统可以添加单元形式与普通FM接收机相连,从而达到以空间分集接收技术改善接收性能的目的.本系统也可以用于车载接收机等移动接收场合.     

Geochemical characteristics and source rock of Ordovician gas reservoir, Changqing Gasfield

Carbon isotopic composition of methane in Ordovician gas reservoir in the Changqing Gasfield can reflect the dominance of Upper Paleozoic coaltype gas despite its high mature degree. The¹²C-rich ethane in the Ordovician reservoir (δ¹³C₂ < −29%), known as a marker as oiltype gas, does not indicate the Ordovician marine carbonate as main source rock, it is because of the relative less ethane content in coaltype gas than in oiltyped gas due to generation and migration. The way of Upper Paleozoic coaltype gas migrating into the Ordovician reservoir is widely through the unconformlty instead of only through the erosion groove in the weathering crust.     

应用程序封面设计方法

本文以ＶＢ５．０为例介绍了封面的设计方法，以实际的例子说明了定时器的使用方法、拉幕技巧及检测键盘和鼠标事件的方法。     

汾河上游县(市)土地撂荒现状分析及成因浅探

汾河上游的土地不仅承载着该地区人类的生产和生活,且对整个汾河流域乃至黄河中下游的生态环境有深远影响.然而,近年来该地区土地撂荒现象日渐突出,严重影响了该地区人类的生产、生活以及生态环境.研究汾河上游包含宁武县、静乐县、岚县、娄烦县、古交市等5个县(市)在内的2000年至2013年期间土地撂荒的动态变化;分析该地区土地撂荒的形成原因,主要成因有自然条件的影响、社会分配制度不够合理、基础设施投入不足等;并针对这些问题提出一些应对对策.     

嘉陵江中游农业产业结构及其合理化初探

嘉陵江中游是１个以农业为主的区域，分析其农业产业结构的变动情况，把握其变动规律，认识其现状特征，确定其合理发展方向和途径，有助于合理利用土地，改善生态环境，实现人口，资源，环境和经济社会的可持续发展。