IPv6与欧洲

在推进IPv6的问题上,亚洲表现的最为积极,这是因为亚洲各国承受着巨大的IP地址方面的压力。欧洲虽然在这方面没有这样大的压力,但在互联网方面一直落后于美国,这是欧洲所不甘心的。因此,欧洲在推进IPv6方面也做了许多工作。欧洲推进IPv6的基本策略是先移动,后固定,并实施了一系列的行动计划和项目。欧洲面临的挑战主要是已经部署了数量巨大的网元、操作系统与软件应用必须予以更新、互通或取代,需要仔细规划和大量投资。     

1/f Noise separated from white noise with wavelet denoising

The low-frequency noise in the devices often appears to be a superposition of 1/f noise and white noise, which are induced by different physical mechanisms or microscopic defects. The separation of the two noises is necessary especially in the characterization of quality and reliability by means of noise measurement. The traditional separation method is usually used in frequency domain with limited frequency range, and the estimated value of exponent index γ for 1/f^γ noise has considerable error when the ratio of 1/f noise and white noise is smaller than 20 dB. In this paper, based on wavelet denoising theory, a new method is proposed to separate 1/f^γ noise from white noise in time domain and can be used to estimate γ values with much better accuracy even if the ratio of 1/f noise to white noise in low enough.     

低压电、汽两用节能加热锅炉的结构特点

通过对电、汽两用节能加热锅炉的描述,指出该设备具有投资少,无污染,能源转化率高,起停速度快,负荷调节范围大,结构简单,安全性能好并可充分利用电能等特点.     

浅谈综采工作面过陷落柱方法

通过分析陷落柱的形成机理,提出过陷落柱的有效方法,以加快综采工作面过陷落柱的速度.     

多元羧酸防皱机理的探讨

多元羧酸的防皱机理是近期织物防皱整理研究讨论的热点。其中，催化剂在体系中所起的作用现有多种说法，如催化成酐，催化成酯，以及既催化成酐又催化成酯和其他一些观点。本文就多元羧酸的防皱机理作一分析和归纳，并提出一些看法。     

电站锅炉制粉系统的爆炸原因与防范对策

火力发电厂制粉系统爆炸事故时有发生 ,重大设备损坏 ,造成了严重的经济损失。本文通过分析研究 ,找出制粉系统爆炸的原因 ,从措施上、煤的质量控制上及制粉系统结构改造上提出了防范的对策。     

Impact of nonlinear phase noise on direct-detection DQPSK WDM systems

The performance degradation of differential quadrature phase-shift keying (DQPSK) wavelength-division-multiplexed (WDM) systems due to self-phase modulation (SPM)- and cross-phase modulation (XPM)-induced nonlinear phase noise is evaluated in this letter. The XPM-induced nonlinear phase noise is approximated as Gaussian distribution and summed together with the SPM-induced nonlinear phase noise. We demonstrate that 10-Gb/s systems, whose walkoff length is larger than 40-Gb/s systems', are more sensitive to XPM-induced nonlinear phase noise than 40-Gb/s systems. Furthermore, DQPSK WDM systems show lower tolerance to both SPM- and XPM-induced nonlinear phase noise than differential phase-shift keying WDM systems.     

JOINING MECHANISMS OF β''''-Al2O3 CERAMIC AND PYREX GLASS TO Al MATRIX COMPOSITE

The bonding of β'-Al2O3 and pyrex glass to Al matrix composites by anodic bonding process is achieved. The microstructure of the bonded interface and the joining mechanisms are analyzed with scanning electron microscope (SEM), energy dispersive X-ray fluorescence spectrometer (EDX). It is observed that the bonding region across the interface consists of the metal layer, oxide transitional layer and the ceramic layer, with the transitional layer composed of surface region and sub-surface region. The bonding process can mainly be categorized into anodic bonding process and solid state diffusing process. The pile-up of the ions and its drift in the interface area are the main reasons for anode oxidation and joining of the interface. The temperature, voltage and the drift ions in the ceramic or glass during the bonding process are the essential conditions to solid state diffusing and oxide bonding at the interface. The voltages, temperature, pressure as well as the surface state are the main factors that influence the anodic bonding.     

兰州重离子加速器大型真空室

已建成的兰州重离子加速器的真空室是一个大型整体结构的超高真空容器,直径约10m,高4.5m,重65000kg,内表面积211m~2,容积100m~3,工作真空度为5×10~(-5)Pa。采用有限单元法在计算机上用SAP-5C程序对真空室受力分析进行了计算。真空室结构材料选用瑞典Uddeholm钢厂生产的316 L 超低碳不锈钢。承制此大型容器的是航天工业部风华机器厂。由于结构庞大,首先将真空室分成八大块和几小块在工厂制造,然后运至现场焊制成一整体容器并进行机械加工。所有密封焊缝均用着色渗透液,X-射线探伤和氦质谱探漏仪进行检查和探漏。