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941.
Low resistivity transparent conducting Al-doped ZnO films prepared by pulsed laser deposition 总被引:1,自引:0,他引:1
Hideaki Agura Akio SuzukiTatsuhiko Matsushita Takanori AokiMasahiro Okuda 《Thin solid films》2003,445(2):263-267
A series of AZO films were grown on glass substrates by a method of pulsed laser deposition using a split target divided into AZO (Al2O3: 1 wt.%) and AZO (Al2O3: 2 wt.%). The film deposition took place at a substrate temperature of 230 °C within a magnetic field applied perpendicularly to the plume. To suppress the droplet generation caused by the intense laser energy, the laser energy density was reduced to 0.75 J/cm2 (15 mJ). For an approximately 280-nm thick-AZO film grown at a target-to-substrate distance of 25 mm, we obtained the lowest resistivity of 8.54×10−5 Ω·cm and an average transmittance of more than 88% in the visible range. In the cross-sectional TEM observation and XRD spectra, the regularity in the crystal growth was generated immediately from the interface between the substrate and the film. 相似文献
942.
Proportional delay differentiation provision by bandwidth adaptation of class‐based queue scheduling
Angelos Michalas Malamati Louta Paraskevi Fafali George Karetsos Vassilios Loumos 《International Journal of Communication Systems》2004,17(7):743-761
Supporting quality of service (QoS) over the Internet is a very important issue and many mechanisms have already been devised or are under way towards achieving this goal. One of the most important approaches is the so‐called Differentiated Services (DiffServ) architecture, which provides a scalable mechanism for QoS support in a TCP/IP network. The main concept underlying DiffServ is the aggregation of traffic flows at an ingress (or egress) point of a network and the marking of the IP packets of each traffic flow according to several classification criteria. Diffserv is classified under two taxonomies: the absolute and the relative. In absolute DiffServ architecture, an admission control scheme is utilized to provide QoS as absolute bounds of specific QoS parameters. The relative DiffServ model offers also QoS guarantees per class but in reference to the guarantees given to the other classes defined. In this paper, relative proportional delay differentiation is achieved based on class‐based queueing (CBQ) scheduler. Specifically, the service rates allocated to the classes of a CBQ scheduler are frequently adjusted in order to obtain relative delay spacing among them. The model presented can also be exploited in order to meet absolute delay constraints in conjunction with relative delay differentiation provision. Simulation experiments verify that our model can attain relative as well as absolute delay differentiation provided that the preconditions posed are satisfied. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
943.
Chen Yih-Farn Huang Huale Jana Rittwik Jim Trevor Hiltunen Matti John Sam Jora Serban Muthumanickam Radhakrishnan Wei Bin 《Wireless Networks》2003,9(4):283-297
iMobile is an enterprise mobile service platform that allows resource-limited mobile devices to communicate with each other and to securely access corporate contents and services. The original iMobile architecture consists of devlets that provide protocol interfaces to different mobile devices and infolets that access and transcode information based on device profiles. iMobile Enterprise Edition (iMobile EE) is a redesign of the original iMobile architecture to address the security, scalability, and availability requirements of a large enterprise such as AT&T. iMobile EE incorporates gateways that interact with corporate authentication services, replicated iMobile servers with backend connections to corporate services, a reliable message queue that connects iMobile gateways and servers, and a comprehensive service profile database that governs operations of the mobile service platform. The iMobile EE architecture was also extended to provide personalized multimedia services, allowing mobile users to remotely control, record, and request video contents. iMobile EE aims to provide a scalable, secure, and modular software platform that makes enterprise services easily accessible to a growing list of mobile devices roaming among various wireless networks. 相似文献
944.
In earlier works on transmitter power control in cellular radio systems, the problem of whether a signal‐to‐interference ratio (SIR) threshold is achievable is determined by apparently different rules for homogeneous and heterogeneous SIR systems. In this paper, we present a unified and more universal framework for both cases. We also highlight the conditions under which a given SIR threshold vector for the heterogeneous SIR system is achievable, although so far there is no general solution to this problem. 相似文献
945.
分布式数据库系统通常采用2PL(两阶段锁定协议)来维护其一致性.本文运用Shadow-Opt方法,通过区分写操作将新旧算法结合从而保证一致性并提高性能. 相似文献
946.
Reviews the book, New Space for Women edited by Gerada R. Wekerle, Rebecca Peterson, and David Morley (1981). New Space for Women is the author's depiction of the need to formally establish a multidisciplinary field of women and the environment. The book is a collection of 17 original review articles selected from diverse areas, including urban design and planning, social services and academic research, organized under this common theme. The papers are grouped into four general themes: the domestic workplace, effects of urban design on women, women as environmental decision makers, and women as environmental activitist. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
947.
948.
本文考虑到下游梯级水库形态的变化同时受到上游梯级水库和其自身水库调蓄运用的影响,提出下游梯级河川式水库冲淤计算的方法。后经紫兰坝水库河工模型验证,表明该法精度良好,计算结果与实验比较一致。 相似文献
949.
NUMERICALSTUDYOFTURBULENTJETSCONFINEDBETWEENTWOCONCENTRICSPHERESZhangGuang-hua;TangGe-feng(TsinghuaUniversity,Beijing,100084,... 相似文献
950.
Soluble poly(2-hydroxyethyl methacrylate) and copolymers of 2-hydroxyethyl methacrylate with n-butyl acrylate and 2-hydroxypropyl acrylate of varying compositions were synthesised by solution polymerisation. The polymers were characterised by dilute solution viscometry and shear viscosity. Crosslinked membranes were prepared from these polymers by introducing crosslinks in solution state through the reaction with 1,6-hexamethylene diisocyanate at a number of different crosslinker concentrations. The membranes swollen in dimethylformamide and water were characterised by performing equilibirium swelling measurements and calculating polymer volume fraction, the molecular mass between crosslinks (M?c) and equilibrium water content (EWC) at 25°C. The calculation of M?c used an expression developed by Peppas & Lucht for equilibrium swelling. This is a modified equation of the original Flory–Rehner expression, that allows non-Gaussian distribution of chain lengths. The variation of M?c with crosslinker concentration and copolymer composition is discussed in terms of structural and molecular characteristics of these highly crosslinked networks. 相似文献