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11.
Lanthanide-based oxysulfides and sulfide, LnTaO3.5S0.5, Ln10OS14 (Ln = La, Pr, Nd, Sm) and La4In5S13, were successively synthesized by sulfurization in a flowing H2S. The sulfurization decreased the band-gap energies from >4 eV to <3eV, because of the formation of occupied S3p orbitals on the top of valence band. In accordance with the small band gap, the H2 evolution from a 0.01 M Na2S and 0.01 M Na2SO3 solution system was observed under irradiation of light up to >500 nm. The rate of H2 evolution under light irradiation of >500 nm increased in the order of Ni/LaTaO3.5S0.5 < Ru/La10OS14 < Pt/La4In5S13.  相似文献   
12.
Application-level performance is a key to the adoption and success of the CDMA 2000. To predict this performance in advance, a detailed end-to-end simulation model of a CDMA network is built to include application traffic characteristics, network architecture, network element details using the proposed simulation methodology. We assess the user-perceived application performance when a RAN and a CN adopt different transport architectures such as ATM and IP. To evaluate the user-perceived quality of voice service, we compare the end-to-end packet delay for different vocoder schemes such as G.711, G.726 (PCM), G.726 (ADPCM), and vocoder bypass scheme. By the simulation results, the vocoder bypass scenario shows 30% performance improvement over the others. We also compare the quality of voice service with and without DPS scheduling scheme. We know that DPS scheme keep the voice delay bound even if the service traffic is high. For data packet performance, HTTP v.1.1 shows better performance than that of HTTP v.1.0 due to the pipelining and TCP persistent connection. We may conclude that IP transport technology is better solution for higher FER environment since the packet overhead of IP is smaller than that of ATM for web browsing data traffic, while it shows opposite effect to the small size voice packet in RAN architecture. We show that the 3G-1X EV-DO system gives much better packet delay performance than 3G-1X RTT. The main conclusion is that end-to-end application-level performance is affected by various elements and layers of the network and thus it must be considered in all phases of the development process. Jae-Hyun Kim He received the B.S., M.S., and Ph.D. degrees, all in computer science and engineering, from Hanyang University, Ansan, Korea, in 1991, 1993, and 1996 respectively. In 1996, he was with the Communication Research Laboratory, Tokyo, Japan, as a Visiting Scholar. From April 1997 to October 1998, he was a post-doctoral fellow at the department of electrical engineering, University of California, Los Angeles. From November 1998 to February 2003, he worked as a member of technical staff in Performance Modeling and QoS management department, Bell laboratories, Lucent Technologies, Holmdel, NJ. He has been with the department of electrical engineering, Ajou University, Suwon, Korea, as an assistant professor since 2003. His research interests include QoS issues and cross layer optimization for high-speed wireless communication. Dr. Kim was the recipient of the LGIC Thesis Prize and Samsung Human-Tech Thesis Prize in 1993 and 1997, respectively. He is a member of the Korean Institute of Communication Sciences (KICS), Korea Institute of Telematics and Electronis (KITE), Korea Information Science Society (KISS), and IEEE. Hyun-Jin Lee received the B.S. degree in electrical engineering from Ajou University, Suwon, Korea, in 2004, and is working toward the M.S. degree and Ph. D. degree in electrical engineering at Ajou University. He has been awarded Samsung Human-Tech Thesis Prize in 2004. His research interests QoS, especially network optimization and wireless packet scheduling. He is a member of the KICS. Sung-Min Oh received the B.S. and M. S. degrees in electrical engineering form Ajou University, Suwon, Korea, in 2004, and is working toward the Ph. D. degree in electrical engineering at Ajou University. His research interests QoS performance analysis and 4G network. He is a member of the KICS. Sung-Hyun Cho received his B.S., M.S., and Ph.D. in computer science and engineering from Hanyang University, Korea, in 1995, 1997, and 2001, respectively. From 2001 to 2005, he has been with Samsung Advanced Institute of Technology, where he has been engaged in the design and standardization of MAC and upper layers of B3G, IEEE 802.16e, and WiBro systems. He is currently a MAC part leader in the telecommunication R&D center of Samsung Electronics. His research interests include 4G air interface design, radio resource management, cross layer design, and handoff in wireless systems.  相似文献   
13.
苏北-南黄海盆地构造演化   总被引:13,自引:1,他引:12       下载免费PDF全文
杨琦  陈红宇 《石油实验地质》2003,25(Z1):562-565
苏北及南黄海盆地是由多期、多类盆地叠加的复合残留盆地,地质概况基本相似,成因演化近同,自元古界下扬子板块形成后,主要经历了古-中生代地台、中生代前陆盆地、走滑拉分盆地时期以及新生代断陷、坳陷盆地时期.在古生代-中生代发展过程中是一个整体,晚白垩世盆地演化出现分化,发育伸展盆地群,形成一系列叠置在中、古生代盆地之上的箕状断陷,箕状断陷的发育及分布明显受中-古生界内部先存逆冲断裂的控制.  相似文献   
14.
Like any other domain of human activity, psychology has its fads and fashions. One consequence of fads is an overconcentration of resources on specific problems or approaches, which leaves other important problems or approaches (holes) underappreciated and understudied. This article is primarily about different factors (such as negativity bias, polarization of positions, focus on internal causes of behavior, dedication to a narrow view of what science is) that result in holes and about explorations of some of these holes that have interested the author. Psychologists should look more in the holes left behind by current enthusiasms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
15.
基于神经网络的降雨径流预报   总被引:2,自引:0,他引:2  
本文将人工神经网络应用于二滩水电站以上支流鱼河的降雨径流预报,通过建模、计算、比较和分析可知,其非线性映射能力、自学习能力和灵活性,均能较好地反映降雨径流之间的非线性的、复杂的转换关系,结合流域水文特性并合理处理建模数据,值得进一步深入研究。  相似文献   
16.
Reorganisation and evolution of class hierarchies is important for object-oriented system development and has received considerable attention in the literature. The contributions of this paper are: (1) a formal study of a set of extension relations and transformations on class hierarchies; (2) a presentation of a small set of primitive transformations which form a minimal and complete basis for the extension relations; and (3) an analysis of the impact of these transformations at the object level.The study leads to a better understanding of evolution and reuse of object-oriented software and class hierarchies. It also provides a terminology and a means of classification for design reuse. The theory presented in this paper is based on the Demeter data model, which gives a concise mathematical foundation for classes and their inheritance and part-of relationships. Parts of the theory have been implemented in the Demeter System TM C++, a CASE tool for object-oriented design and programming.  相似文献   
17.
Leaching of cementitious materials leads to an increase in porosity, which has important consequences on transport and mechanical properties. The present study outlines the characterization of microstructural evolution in a mortar subjected to a chemical attack, by means of a powerful non-intrusive experimental method, namely synchrotron X-ray computed microtomography. This innovative method is used to measure the variation of porosity in a leached mortar. Having described the effects of leaching in mortar (influences on microstructure and on mechanical properties), we present the accelerated leaching process and the microtomographic analysis that have been used to monitor it. We then investigate the capacity of this method to quantify the evolution of porosity during the leaching process. The method is validated by comparison of the results obtained with data available in the literature.  相似文献   
18.
川中丘陵区一种新型小流域径流输沙模型的建立与应用   总被引:1,自引:0,他引:1  
径流输沙模型对定量评价水沙的输出响应具有重要的意义。本研究在已有研究成果的基础上,通过对四川盐亭县林山西沟小流域的径流、泥沙进行现场观测与分析,提出含沙量单位线的定义及其确定方法,建立了适应该小流域的径流输沙模型。并应用实测资料进行比较,表明模型的模拟结果可靠,模拟过程确定性系数达0.8以上,为川中丘陵区小流域径流输沙过程的预测预报提供了一个新方法。  相似文献   
19.
环件轧制中晶粒变化的计算机模拟   总被引:9,自引:1,他引:8  
金属微观结构变化影响产品机械性能。本文将金属再结晶数学模型与三维热刚塑性有限元结合起来进行模拟计算,获得了环件轧制中晶粒变化的三维分布规律,及与以往不同的轧制力和力矩变化。所用方法有普遍适用性。  相似文献   
20.
本文简要的介绍了瀑布沟工程水文分析计算主要依据站的选定和基本资料的插补延长,以及径流、洪水的分析计算方法.在可行性研究阶段水文成果(通过审查)和新设立的毛头码水文站所取得的数年水文资料的基础上,将初设阶段对可行性研究阶段的水文分析计算方法和成果进行验证和补充的情况重点予以介绍.  相似文献   
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