浅议iSCSI存储网络技术及其应用

本文从存储系统技术分类、iSCSI存储网络设备分类、iSCSI协议分析、iSCSI存储网络技术的特点、iSCSI存储网络技术的应用等方面，就iSCSI存储网络技术及其应用进行论述和分析。     

支持IP-SAN远程映射与引导的固件协议栈

设计了一种基于IP存储区域网络的远程引导技术,该技术的核心是运行在裸机下的固件协议栈.针对固件协议栈运行特性,提出了一种非路由iSCSI/TCP通信协议原型,并实现了基于固件的iSCSI/TCP协议.同时提出了几种优化算法以提升远程引导性能与可靠性,包括乐观预测、固定回避重传算法和避免协议栈重入的输出请求挂起策略.建立了一种便于操作系统内核iSCSI启动器平滑接管的固件iSCSI启动器有限状态模型.通过将固件协议栈集成到IP-SAN扩展BIOS中,并应用于无本地存储设备的主机上,实现了基于IP-SAN的网络引导,测试结果表明该固件协议栈有很好的性能和可靠性,并且部署、移动和重新分配主机与存储卷之间的映射关系变得更加便利.     

基于IP的iSCSI技术发展状况

存储IP化是存储技术发展的方向，目前提出的iSCSI技术受到业界的支持，在支持Storage over IP技术的SCSI over IP(iSCSI)、Fibre Channel over IP(iFCP)和iSNS协议中，iSCSI技术是在以太网上传输SCSI指令的技术，它既有NAS在以太网传输存储信息的特性，又有SAN传输数据块的快速性，在NAS和SAN之间架设了道桥梁，在未来市场上很有可能占主导地位。因此，iSCSI也被认为是未来网络存储的一个发展方向。     

基于光纤通道和IP网络的两种存储协议转换的设计和实现

存储区域网(SAN)的产生,很好的解决了当今数据爆炸所带来的难题。两种存储区域网FCSAN和IPSAN都得了飞速的发展。FCSAN和IPSAN网络分别使用了不同的通信协议。本文主要针对FCSAN中的FCP协议和IPSAN中的iSCSI协议这两种协议之间的转换进行研究。     

无线网络中iSCSI性能的研究

在介绍和分析标准iSCSI协议体系结构的基础上,给出了在iSCSI会话中通过建立多个虚拟TCP连接且在无线局域网中的iSCSI层采用并行工作机制的优化方法,并对其性能进行了理论分析和实验测试.结果表明,与标准iSCSI相比,在无线网络中使用多连接TCP能有效的改善iSCSI协议的存储性能.     

跨部门数据共享的安全存储机制研究

作为一种新型网络存储架构,IPSAN存储网络可提供集中、统一和共享的存储服务,在跨部门数据安全共享需求日益迫切的背景下,基于IPSAN的安全存储可实现对数据共享的有效控制。文中通过对跨部门数据共享需求和IPSAN集中存储网络的应用安全研究,提出了跨部门数据安全存储方案,给出了存储资源授权访问模型,并设计了一个基于iSCSI协议的安全存储控制系统。     

新型IP网络存储器性能比较

用实验方法比较NFS、iSCSI(存储设备)、基于iSCSI协议的OSD网络(OSDN)和CAS网络(CASN)的性能,并分析它们的性能瓶颈和优化方向.实验表明,它们的性能是接近的,不同存储操作的性能是不同的:iSCSI的读操作和CASN的写操作性能显著优于其他系统;CASN相对于OSDN的读写操作性能优势随数据传送长度增加而减小.     

数据中心桥接交换机FCoE相关特性及其测试方法简介

IP协议统治了Internet,下一个目标指向了存储区域网络(SAN),开始和FC协议进行对抗,并将SCSI协议IP化,形成了iSCSI协议标准,凭借其自身的特点迅速占领了部分存储网络市场。近年FC几乎已经成了SAN的代名词,他当然不会束手就擒,你拉拢了我的盟友SCSI,我也拉拢你的盟友以太网,形成了FCoE协议。当然IP和FC也会和谈,形成了如FCIP和IFCP等协议,但和谈的产物复杂度增加,应用的不多。iSCSI和FCoE是两种主流的融合协议。思博伦通信杨涛所撰《数据中心桥接交换机FCoE相关特性及其测试方法简介》一文主要介绍了数据中心桥接交换机的FCoE相关特性,DCB分成多种,典型的DCB增加了FC或FCoE接口,将以太网和存储区域网络连接起来,就像桥一样。主机读写数据时通过FCoE协议访问存储设备,和其他设备通讯时仍使用IP等协议。     

iSCSI-SAN分级管理结构及其访问控制模型设计

介绍了基于iscsi（Internet小计算机系统接口）协议构建存储区域网的网络存储技术,分析了iSCSI—SAN（存储区域网）的通信机制和管理结构,针对典型的集中式管理结构存在的管理服务器瓶颈、单点故障和管理复杂的不足提出了iSCSI—SAN分级管理结构,通过将存储的管理工作逐级授权简化了管理工作,并能有效地解决服务器瓶颈和单点故障问题,最后根据结构特点给出了一种基于权限证书的访问控制解决方案,防止合法用户对存储数据的越权访问和未授权用户的非法访问,提高了系统的安全性。     

SCSI产品的未来?

通过在广泛普及的IP网络上传送SCSI命令,iSCSI市场终于准备好起步了。iSCSI承诺更为方便的企业内部互联网上的数据传输,以及简化长距离范围内的存储管理。在广泛的应用中,包括远程备份,远程镜像,SAN桥接和低成本的存储区域网,该技术预计可以为这些应用带来令人感到兴奋的新功能。新协议最终允许通过为光纤信道存储区域网提供一种新的低成本可选方案,以及比直连存储(DAS)更灵活的来实现快速的SAN部署。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.