Applying File Information to Block-Level Content Addressable Storage

Content addressable storage (CAS) is a promising technology for improving storage efficiency as well as access throughput.Currently,many CAS products are implemented on the block level,which results in loss of file information.Thus,some sophisticated optimizations cannot be achieved,such as accurate fileprefetching.This paper presents a file-aware block-level storage system combined with the CAS function.In contrast with some existing file-level CAS,this system is transparent to upper-level applications,including the operating system and the file system.These features are achieved by using smart-disk technologies to help the storage system to learn the file-system layout.A prototype was implemented on an open-source virtual machine (VM) with the guest operating system being Windows XP.Tests show that this combination significantly reduces the size of the VM image file and improves the storage performance by discarding unused blocks and using a simple file-level prefetching strategy.     

Al-Fe系金属盐絮凝剂在β-SiC微粉分级中的性能研究

简要综述了无机絮凝剂的性能.根据无限微热源法合成的β-SiC微粉产品的表面性能,以及AI-Fe系金属盐絮凝剂性能,在β-SiC微粉分级分选过程中,通过加入不同种类、浓度配比的外加剂,测定其絮凝时间和溶液浊度,对比得到适合于无限微热源法合成β-SiC微粉分级分选的外加剂.结果显示,AI-Fe系金属盐絮凝剂可应用于无限微热源法合成的β-SiC微粉的分级分选过程中,在最佳配比和浓度下能够良好地加速分级沉降速度,减小操作难度,提高分级分选效率.     

Rapid Manufacturing of Sand Molds by Direct Milling

Direct milling of sand molds is an important development in rapid manufacturing of sand molds. Direct milling is an effective method for manufacturing single or small batches of cast parts. This paper describes experimental investigations to find sand blocks with the appropriate strength, to describe wear patterns of different tools (high-speed steel (HSS), carbide, and polycrystalline diamond (PCD) tools), and to analyze sand mold cutting mechanisms. The results show that the PCD tool outperformes the other tools in terms of tool life. Average flank wear and micro-tipping are the dominant tool failure modes in the sand mold milling process. With a flank wear limit of 0.3 mm, the PCD tool works continuously for about 70 h under the experimental conditions. The experimental results show that the cutting mechanism for direct milling sand molds differs from metal cutting.     

单点系泊物体长周期运动的统计研究

本文根据实测数据分析了单点系泊物体绕系泊点作360°回转的概率,统计了系泊船船向与风向的相关性。结果表明,在一般海域作360°回转的概率是很小的;船向与风向的相关系数为0.826,因此作者认为,引起360°回转的主要原因是风,实用上可以根据主风向的回转概率或风玫瑰图来推断单点系泊物体的回转概率。     

公益工商研究所始末

本文系统地介绍了由中国最大的民族资本集团——荣家企业经营的公益工商研究所的创办过程及其所进行的研究课题和所取得的成果。文中指出该所是为荣家企业的生存和发展服务的,是集工业、科技、经济于一体的研究机构。     

课程总表调排系统结构模型的解析

介绍课程总表调排系统的结构模型及其解析方法,根据结的模型中的相邻矩阵、可达性矩阵及结构矩阵的建立、分解和求解,给出多级递阶结构图,从而对课程总表的调排进行决策,并且说明课程调排的变动受到诸多因素影响和限制。这种方法可应用于计算机教学管理系统。     

小速比柔性传动理论及应用

将小速比柔性传动研究成果应用在龙门吊车大车走行传动系统上,建立了柔性传动力学模型.通过现场实测,证明了理论计算与实测结果相近。柔性传动其动载系数明显下降,抗缓冲效果良好,经过两年多实际运行消除了断轴、减速机箱体涨裂等事故。     

月桂酸氯仿溶液萃取Nd（Ⅲ）机理研究

在20±1℃、μ=0.1(NaClO_4)条件下,研究了月桂酸氯仿溶液萃取Nd(Ⅲ)机理。假定的萃取反应为:结果表明,上述萃取反应平衡式中j=1和a=0,并得到萃取反应平衡常数为