Reed-Solomon算法在RAID6系统中的应用

本文通过对纠错编码理论及有限域数学理论的研究分析,发现利用其二者相通的性质及运算规则,可以将基于Galois域的Reed-Solomon算法应用到RAID6(Redundant Array of Independent Disk 独立冗余磁盘阵列)磁盘阵列当中进行数据的恢复,并对此技术方法的性能进行了分析.     

炉水游离碱来源及其阻断

阐述了高压锅炉炉水中游离碱的来源。指出补给水品质不良是炉水游离碱的一个重要来源。改善补给水品质不但是消除炉水中游离碱的一种有效途径 ,而且还可以降低炉水排污率 ,具有显著的经济和社会效益。     

Surface analysis of oligothiophene films using HREELS: molecular orientation effects

The surface of evaporated films of α-oligothiophenes—quaterthiophene (4T), quinquethiophene (5T) and sexithiophene (6T)—was studied by high-resolution electron energy loss spectroscopy (HREELS), extending the common vibrational domain of energy loss to electronic excitation and secondary emission. Vibrational spectra show that the molecular orientation is not the same on graphite and gold substrates. HREELS results corroborate those obtained by reflection–absorption infrared spectroscopy (RAIRS), confirming that graphite substrates induce films where molecules lie flat on the surface, whereas gold substrates generate a molecular orientation close to perpendicularity. Using these two differently oriented samples, we demonstrate the existence of two relaxation channels for the electron surface interaction: electronic excitation and ionisation. HREELS spectra recorded with incident electron energy between 2 and 7 eV reveal that secondary electron emission originating from ionisations is always more efficient for escape directions perpendicular to the plane of the molecule. This is here associated with the π orbital origin of this emission. Copyright © 2000 John Wiley & Sons, Ltd.     

大型发电机内冷却水微碱性循环处理技术的开发与应用

介绍发电机内冷水微碱性循环处理技术的原理和方法。该技术选用特殊的离子交换树脂,并采用独特的树脂床层结构,使发电机内冷水经过处理后含有氢氧化钠,水质因此而得以调节,减缓了发电机铜线棒的腐蚀。因该系统无需加药,并且几乎不用换水和补水,故节省了人力和物力。经在4台200MW和6台300MW发电机内冷水系统应用,处理后水质均优于相关标准。     

Expanding the Scope of Protein Trans‐Splicing to Fragment Ligation of an Integral Membrane Protein: Towards Modulation of Porin‐Based Ion Channels by Chemical Modification

It's raining, it's porin : Fragment ligation of OmpF ion channels was achieved by using the split Psp‐GBD Pol intein; this allowed reconstitution of active trimeric porin. In combination with cysteine modification at an internal position, the porin's conductance properties were altered.

     

Verifiable shuffles: a formal model and a Paillier-based three-round construction with provable security

A shuffle takes a list of ciphertexts and outputs a permuted list of re-encryptions of the input ciphertexts. Mix-nets, a popular method for anonymous routing, can be constructed from a sequence of shuffles and decryption. We propose a formal model for security of verifiable shuffles and a new verifiable shuffle system based on the Paillier encryption scheme, and prove its security in the proposed dmodel. The model is general and can be extended to provide provable security for verifiable shuffle decryption.This paper is the extended version of the paper [37] presented at ACNS ‘04.     

预测钻控影响产量的多元线性回归方法

为了在原油年度规划编制中更加准确地预测钻关对产量的影响,采用多元线性回归理论,对钻关影响产量的因素,如钻关前井网密度、含水、流动系数、采油强度、油水井数比、注水强度以及地层压力等进行了回归分析,采取后退法进行了变量筛选,建立了相对最优的预测方程.通过多元线性回归显著性分析,钻关影响产量的主要因素是钻关前的井网密度,其次为含水和流动系数,影响最小的为采油强度和油水井数比.经验证,建立的回归方程预测精度高,可以满足实际要求,在今后的油田生产中,可以利用该回归方程预测钻关对产量的影响.     

Spatial distribution of lamella structure in PCL/PVB band spherulite investigated with microbeam small- and wide-angle X-ray scattering

The microbeam small- and wide-angle X-ray scattering (SAXS/WAXS) technique gives the novel information about micron-scale structural inhomogeneity of polymer crystal. By using this technique, we have studied structural inhomogeneity of lamella within the band spherulite of miscible polymer blend poly(ε caprolactone) (PCL)/poly(vinyl butyral) (PVB) and the structure development of lamella during crystallization. It is known that PCL/PVB forms very large spherulites (∼several mm in radius) with highly regular band structure because of low frequency of nucleation and that PCL/PVB crystallized at 41 °C has at least two kinds of lamella structure (150 Å, 180 Å). With an X-ray microbeam initially fixed outside near the growth front of the band spherulite, we have observed the lamella formation at the local point and have found that the larger long period grows before the appearance of the shorter long period. We have also observed that the orientation of lamella with the larger long period is different from that of lamella with the shorter long period from SAXS experiment with an X-ray microbeam scanning the band spherulite along its radial direction. Further, the discontinuity in lamella twisting was observed from scanning microbeam WAXS. Based on the experimental results, we propose two possible spatial distribution models. The result of PCL/PVB crystallized at 35 °C was also discussed.     

Electron transfer rate of redox ion controlled by electrostatic interaction with bilayer films assembled using thiolate-copper ion-carboxylate bridges

11-mercaptoundecanoic acid (MUA) monolayer and MUA-copper ion-MUA bilayer assembled using thiolate-coppcr ion-carboxylate bridges on MUA monolayer electrode were prepared, and tried to control electron transfer rate of redox ions. The soaking solution to assemble MUA on gold electrode changed from ethanolic MUA solution to 1-butanolic one, then the differential interfacial capacitance decreased from 2.5±0.1 μF cm⁻² to 1.6±0.2 μF cm⁻², and electron rate constant, k⁰ of [Co(phen)₃]³⁺ decreased from 20×10⁻⁶ cm s⁻¹ to 8.3×10⁻⁶ cm s⁻¹. These results show that highly ordered MUA monolayer can be obtained only changing soaking solvent to assemble MUA, Obtained highly ordered MUA monolayer electrode was block off completely redox anion by electrostatic repulsion and MUA film thickness. Moreover using MUA-copper ion-MUA bilayer electrode, k⁰ of [Co(phen)₃]³⁺ decreased under 1/400 against using MUA monolayer electrode, that value become to under 0.02×10⁻⁶ cm s⁻¹. This study shows that the combination of electrode surface charge and length of insulating spacers is able to control electron transfer rate of various electroactive ions.     

Convexity of reachable sets of nonlinear ordinary differential equations

A necessary and sufficient condition for the reachable set, i.e., the set of states reachable from a ball of initial states at some time, of an ordinary differential equation to be convex is presented. In particular, convexity is guaranteed if the ball of initial states is sufficiently small, an upper bound on the radius of that ball being obtained directly from the right hand side of the differential equation. In finite dimensions, the results cover the case of ellipsoids of initial states. A potential application of the results is inner and outer polyhedral approximation of reachable sets, which becomes extremely simple and almost universally applicable if these sets are known to be convex. An example demonstrates that the balls of initial states for which the latter property follows from the results are large enough to be used in actual computations.