Enhanced Hardness of Transparent HAp Ceramic by Microstructure Refinement

Transparent hydroxyapatite(HAp) ceramics with the grain size ranging 86-1 300 nm were successfully synthesized by spark plasma sintering(SPS) at 925-1 200 ℃. All the sample achieved final density higher than 99.7%. The phase stability was identified by X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR). The experimental results indicate that there is no decomposition or dehydroxylation during the SPS processes. The influences of microstructure refinement on the hardness were investigated using HallPetch(H-P) relationship, and the hardness of transparent HAp ceramic increases with the decrease of grain size. It is demonstrated that the grain boundaries and defects play important roles on the hardness.     

三峡工程升船机及临时船闸高边坡施工期监测

主要分析了在施工期影响三峡工程升船机及临时船闸高边坡稳定的因素，并介绍了对高边坡安全进行仪器监测，同时开展现场巡视检查的情况。     

小浪底水库坝前漏斗区泥沙测验分析

小浪底水库坝前漏斗区的形成和发展,直接影响到枢纽建筑物的安全运行。为了保持塔前“门前清,”掌握坝前漏斗区的形成和发展,保证水库进入拦沙后期和正常运用期的正常运用,对坝前漏斗区进行了泥沙测验分析。结果表明:目前漏斗区范围内纵向坡度较缓,尚没有明显的漏斗形成,仅在坝前和塔前200m×1000m范围形成了漏斗雏形。     

主成份回归在混凝土坝无应力变形测值分析中的应用

对混凝土坝无应力变形实测资料目前常用的分析方法进行了评述,然后介绍了主成份回归分析的基本原理和方法,最后结合某工程17号坝段无应力变形实测资料展示了主成份回归在资料分析中的应用。结果表明这种方法是切实可行的,可以得到质量较高的成果。     

羊毛改性技术及应用研究

介绍了三种羊毛改性技术即氯化法，酶化法，氯化－酶化法及其优缺点比较。     

Evaluation of Morphology—Stable Critical Size of KNbO3 Crystals

Skeletal form of KnbO3 crystals growing in Li2B4O7 solvent was in-situ observed at 900℃ and it was found that shallow depression started to develop on the surface of KnbO3 crystals when the crystal size exceeded several micron,typically 7 micron.Based on the quantitative criterion derived by Chernov,the estimated critical size of KNbO3 crystals was 1 micron,which was consistent with the experimental measurement.The kinetic coefficients,Kcorner and Kcr,in the criterion were experimentally obtained in the diffusive-convective and diffusive-advective flow states respectively.     

The Effects of Filtered Channel Quality Feedback on Throughput of Proportional Fair Algorithm

1　IntroductionSchedulingalgorithmsarewidelystudiedforwirelesspacketdatasystems,whichgenerallyhavetwobasiccategories,oneisoptimizedforsystemthroughputandfairness[1～ 2 ] ,andtheotherisforthequalityofservice[3～6] .Forsystemswherepack etdataaretimedivisionmultiplexedacrossusersonthedownlink ,orfromBaseStation (BS)tomultipleMobileStations(MS) ,theBSusesschedulingalgo rithmstodecidewhichuseristransmittedto .ItisindicatedinRefs.[7,8]thatschedulingonlyoneus eratatimeisoptimalfromthepointofviewo…     

NUMERICAL SIMULATIONS OF 2D PERIODIC UNSTEADY CAVITATING FLOWS

1. INTRODUCTION Cavitation is a natural phenomenon especially existing in liquids. A cavitating flow generally involves a large number of vapor structures such as bubbles or vortices which are convecting downstream. When they reach high pressure zones, th…