Nanoraspberry-like palladium/spongy nickel oxide for electrooxidation of five light fuels

The spongy nickel oxide (SNO) was synthesized the solution combustion method. The SNO was selected as a promoter to boost the catalytic activity of nanoraspberry-like palladium (NRPd) toward electrooxidation of five light fuels (LFs): methanol, ethanol, formaldehyde, formic acid, and ethylene glycol. The X-ray powder diffraction, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy, and field emission scanning electron microscope techniques were used for the materials characterization. In comparison with nonpromoted Pd, the NRPd-SNO electrocatalyst shown an excellent efficiency in parameters like the electrochemical active surface area and anti-CO poisoning behavior. The turnover data and the parameters, including reaction order, activation energy, and the coefficients of electron transfer and diffusion, were evaluated for the each process of LFs electrooxidation. The outcome for NRPd-SNO activity toward LFs electrooxidation was compared to some reported electrodes. The SNO increases the removal of intermediates created in the oxidation of LFs that can poison the surface of palladium catalyst. This is due to the presence of the lattice oxygens in SNO structure and Ni switching between its high and low valances. The compatibility of the adsorption process of LFs on the surface of the NRPd-SNO catalyst with different isotherms was determined by studying the Tafel polarization and calculating the surface coverage.     

基于桥连接的词典学习方法的语义解析

现阶段的语义解析方法大部分都基于组合语义,这类方法的核心就是词典。词典是词汇的集合,词汇定义了自然语言句子中词语到知识库本体中谓词的映射。语义解析一直面临着词典中词汇覆盖度不够的问题。针对此问题,该文在现有工作的基础上,提出了基于桥连接的词典学习方法,该方法能够在训练中自动引入新的词汇并加以学习,为了进一步提高新学习到的词汇的准确度,该文设计了新的词语—二元谓词的特征模板,并使用基于投票机制的核心词典获取方法。该文在两个公开数据集(WebQuestions和Free917)上进行了对比实验,实验结果表明,该文方法能够学习到新的词汇,提高词汇的覆盖度,进而提升语义解析系统的性能,特别是召回率。     

海河流域河道外生态需水研究

水土流失是海河流域较为突出的生态环境问题之一。经对比研究发现，植被覆盖度的变化会通过影响洪充量，土壤侵蚀量等因子，进而改变水土流失的状况。从提高植被覆盖度尤其是低覆盖度草地植被的角度出发，定量研究了为改善流域水土流失状况河道外生态需水的具体数额，得出海河流域现状年河道外生态耗水（降水）385亿m^3。另外，为改善河道外生态环境状况将低覆盖度草地提高地提高至中等覆盖度水平，则需要增加生态需水12．5亿m^3。     

Using Bandwidth-Space Partitioning to Improve Cell Coverage and Near-Far Unfair Access Problem in a Noise-Limited CDMA Cellular Network

This paper concerns CDMA cellular networks equipped with conventional matched filter receivers. For this type of cellular networks, two problems exist. One is the inverse relationship between the coverage and capacity, and the other one is the near-far unfair access problem. To resolve these two problems, a bandwidth-space partitioning technique is adopted. Several admission control schemes based on the bandwidth-space partitioning technique are proposed, and their performances are evaluated based on the simulation.Shih-Tsung Yang received his B.S. (1989) and M.S. (1991) degrees in electrical engineering from the National Taiwan University, and Ph.D. (1999) degree in electrical and computer engineering from University of Maryland, College Park.From 1999 to 2000, he was with SBC Technology Resourtces, Inc. where he was involved in the network architecture design for the ATM based networks. From November 2000 to May 2003, he was with Transilica/Microtune where he was involved in the design of Baseband and RF for the wireless communications. Since May 2003, Dr. Yang is now with Genesys Logic, Inc. where he is responsible for the baseband design of the WLAN and Ethernet.Dr. Yang’s research interests are in the area of Digital Communications, Communication networks and signal processing. E-mail: thomas.yang@genesyslogic.com.twAnthony Ephremides received his B.S. degree from the National Technical University of Athens (1967), and M.S. (1969) and Ph.D. (1971) degrees from Princeton University, all in Electrical Engineering. He has been at the University of Maryland since 1971, and currently holds a joint appointment as Professor in the Electrical Engineering Department and in the Institute of Systems Research (ISR) of which he is a founding member. He is co-founder of the NASA Center for Commercial Development of Space on Hybrid and Satellite Communications Networks established in 1991 at Maryland as an off-shoot of the ISR. He served as Co-Director of that Center from 1991 to 1994.He was a Visiting Professor in 1978 at the National Technical University in Athenas, Greece, and in 1979 at the EECS Department of the University of California, Berkeley, and at INRIA, France. During 1985-1986 he was on leave at MIT and ETH in Zurich, Switzerland. He was the General Chairman of the 1986 IEEE Conference on Decision and Control in Athens, Greece and of the 1991 IEEE International Symposium on Information Theory in Budapest, Hungary. He also organized two workshops on Information theory in 1984 (Hot Springs, VA) and in 1999 (Metsovo, Greece). He was the Technical Program Co-Chair of the IEEE INFOCOM in New York City in 1999 and of the IEEE International Symposium on Information theory in Sorrento, Italy in 2000. He has also been the Director of the Fairchild Scholars and Doctoral Fellows Program, an academic and research partnership program in Satellite Communications between Fairchild Industries and the University of Maryland. He won the IEEE Donald E. Fink Prize Paper Award (1992) and he was the first recipient of the Sigmobile Award of the ACM (Association of Computer Machinery) for contributions to wireless communications in 1997. He has been the President of the Information Theory Society of the IEEE (1987) and has served on its Board of Governors almost continuously from 1981 until the present. He was elected to the Board of Directors of the IEEE in 1989 and 1990. Dr. Ephremides has authored or co-authored over 100 technical journal papers and 300 technical conference presentations. He has also contributed chapters to several books and edited numerous special issues of scientific journals. He has also won awards from the Maryland Office of Technology Liaison for the commercialization of products and ideas stemming from his research. He has served on the Editorial Boards of the IEEE Transactions on Automatic Control, IEEE Transactions on Information theory, the Journal of Wireless Networks, and the International Journal of Satellite Communications.He has been the Dissertation Supervisor of over twenty Ph.D. students who now hold prominent positions in academia, industry, and research labs. He is the founder and President of Pontos, Inc., a Maryland company that provides technical consulting services, since 1980.Dr. Ephremides’ interests are in the areas of communication theory, communication systems and networks, queueing systems, signal processing, and satellite communications. His research has been continuously supported since 1971 by NSF, NASA, ONR, ARL, NRL, NSA, and Industry. E-mail: tony@eng.umd.edu     

基于E语言的外部存储器接口的功能验证

在SoC设计中，传统功能验证方法已显示出其缺点，主要问题有：复杂验证场景难以构建；边缘情况难以覆盖。针对这些问题，业界提出了一种新的功能验证方法学——受限随机矢量生成的功能验证，该方法在满足约束条件的前提下，随机产生验证矢量。本文研究了受限随机矢量生成的功能验证在SoC设计中的应用，并以基于E语言和Specman验证平台验证了SoC芯片中的外部存储器接口，给出了具体的验证环境和验证步骤。验证结果表明，复杂验证场景和边缘情况的覆盖率均达到了100％。极大地提高了验证的效率和质量。     

地面数字声音广播（DAB）及其覆盖规划的考虑

简要描述了近几年来研究开发的为移动、便携和固定接收服务的地面发射数字声音广播(DAB)系统总的特点、应达到的技术和运行要求。重点介绍了系统采用的最适合克服移动接收中出现的多径效应影响的先进源编码技术(MUSICAM)、信道编码技术(COFDM)等的基本原理、系统参数、并介绍了规划DAB业务时,在VHF/FM频段考虑的最佳频段及频谱利用改善情况,还提供了DAB单频网洛(SFN)覆盖的大体情况。其内容取材均来自1990～1992年EBU、CCIR等的最新文稿资料。     

一种新型微处理器功能验证

文中介绍一种新型微处理器的验证方法，并对相关的一些验证策略进行深入的讨论。     

基于蚁群算法的区域覆盖卫星星座优化设计

首先建立了以区域覆盖性能为目标的卫星星座参数优化模型,通过在连续域定义新的蚂蚁分类与转移策略改进了蚁群算法,使算法能够兼顾多目标优化时目标不兼容的情况,给出了基于该算法实现星座参数优化的框架。优化仿真实验验证了该算法的有效性,可为星座方案决策提供有力的支持。     

Low-resistance polysilicon process in contact application for high density devices

For the lowest resistance, it is required to have the epitaxial silicon contact between the silicon plug and the substrate and good step coverage at the high aspect-ratio contact holes, simultaneously. In this work, a double polysilicon (DPS) deposition technique was proposed for the requirements. The first, thin silicon layer is deposited in a single-wafer process chamber with an in-situ H₂-RTP (rapid thermal process) treatment for the epitaxial contact, and the second silicon layer is formed in a batch-type furnace for good step coverage. From chain resistance, Kelvin R_c, and current-voltage (I–V) measurement, the DPS process meets both low resistance and good uniformity, so that it suggests a breakthrough in the small-sized, semiconductor device application.     

黄河流域多沙粗沙区植被覆盖变化与减水减沙效益分析

通过遥感手段和数字流域模型,研究了黄河流域多沙粗沙区近10来年的植被覆盖变化及其减水减沙效益。研究表明,多沙粗沙区90年代末期与80年代末期相比,植被覆盖度增加区域大约占50%,植被覆盖度没变化区域约占48%。植被覆盖度的变化导致了流域水沙条件的变化,90年代末期植被覆盖条件下,植被措施的减水减沙百分比不高;不同的降雨过程,植被措施的减水减沙效益有一定的差别;从不同降雨过程多年平均看,近10来年植被措施年均减水2.63亿m3,减沙1.13亿t,减水减沙比为2.75,即减1亿t沙的同时减水2.75亿m3,减水百分比为7.61,减沙百分比为10.56,减沙效益大于减水效益。