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Effect of the Sputtering Parameters on the Structure and Properties of Cu_3N Thin Film Materials

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Journal of Wuhan University of Technology(Materials science) 2010年第6期25卷 935-937页

作者：钱显毅黄致新 School of electronic Information & Electric engineering Changzhou Institute of Technology college of Physical science and Technology Cental China Normal University

Copper nitride （Cu3N） thin films were successfully deposited on glass substrates by reactive radio frequency magnetron *** effects of sputtering parameters on the structure and properties of the films were *** experimental results show that with increasing of RF power and nitrogen partial pressure,the preferential crystalline orientation of Cu3N film is changed from （111） to （100）.With increasing of substrate temperature from 70 ℃ to 2.0 ℃,the film phase is changed from Cu3N phase to *** increasing sputtering power from 80 W to 12. W,the optical energy decreases from 1.85 eV to 1.41 eV while the electrical resistivity increases from 1.45 ×102.Ω·cm to 2.99×103 Ω·cm,respectively.

关键词： copper nitride sputtering parameters structure electrical and optical properties

A self-calibration algorithm for cross array in the presence of mutual coupling

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science china(Information sciences) 2011年第4期54卷 836-848页

作者： HU XiaoQin 1,2.CHEN Hui 2.WANG YongLiang 2.& CHEN JianWen 2.1 college of electronic {2. and engineering,National University of Defense Technology,Changsha 410073,china 2.Key Lab of Wuhan Radar Academy,Wuhan 430019,china 1. college of electronic {2. and engineering National University of Defense Technology Changsha 410073 China2. Key Lab of Wuhan Radar Academy Wuhan 430019 China

In this paper,a novel blind mutual coupling self-calibration algorithm especially tailored to cross array is *** method compensates for the mutual coupling not only between sensors in each subarray but also between two *** the property of coupling matrix,the proposed method requires neither the calibration sources in known locations nor the multidimensional nonlinear *** method can jointly estimate the DOAs of the incoming signals and the unknown mutual coupling coefficients,and has high estimation precision and low computational *** analysis and computer simulations show the effectiveness of the proposed algorithm.

关键词： cross array mutual coupling self-calibration DOA estimation

DBLAR:A DISTANCE-BASED LOCATION-AIDED ROUTING FOR MANET

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Journal of electronics(china) 2009年第2期26卷 152-160页

作者： Wang Kun Wu Meng college of Communication and Information engineering nanjing University of posts and {2. nanjing 2.0003 china

In location-aided routing of Mobile Ad hoc NETworks(MANET),nodes mobility and the inaccuracy of location information may result in constant flooding,which will reduce the network *** this paper,a Distance-Based Location-Aided Routing(DBLAR) for MANET has been *** tracing the location information of destination nodes and referring to distance change between nodes to adjust route discovery dynamically,the proposed routing algorithm can avoid flooding in the whole ***,Distance Update Threshold(DUT) is set up to reach the balance between real-time ability and update overhead of location information of nodes,meanwhile,the detection of relative distance vector can achieve the goal of adjusting forwarding *** results reveal that DBLAR performs better than LAR1 in terms of packet successful delivery ratio,average end-to-end delay and routing-load,and the set of DUT and relative distance vector has a significant impact on this algorithm.

关键词： Location-aided routing Relative distance vector Mobile Ad hoc NETworks(MANET)

Surface Nanocrystallization of Magnesium Alloy AZ91D by High-Energy Shot Peening

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Journal of Wuhan University of Technology(Materials science) 2009年第4期24卷 515-519页

作者：张津 School of Materials science & engineering University of Science and Technology Beijing college of Materials science & {2. Chongqing University of Technology

High-energy shot peening （HESP）, a method to produce severe plastic deformation by high velocity flying balls, was applied on die cast magnesium alloy AZ91D. Effects of surface nanocrystallization by HESP and heat treatment at different temperatures were investigated. The mi- crostructure evolution was conducted using X-ray diffraction （XRD） and field emission scanning electronic microscopy （FESEM）. The hardness was measured by microhardness tester. The experimental results show that surface nanocrystrallization of AZ91D obtained by HESP would lead to the increase of microhardness. Low temperature heated at 100℃ for 1 h do not change the property obviously. However, both the microstructure and microhardness vary greatly after heat treatment at 400℃ for 1 h.

关键词： AZ91 D surface nanocrystallization HESP microhardnss corrosion resistance

Model-based approach for available bandwidth prediction in multi-hop wireless networks

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science china(Information sciences) 2011年第9期54卷 1916-1927页

作者： ZHAO HaiTao 1,WANG Shan 1,WEI JiBo 1,SONG An 1 & LI Ying 2.1 college of electronic {2. and engineering,National University of Defense Technology,Changsha 410073,china 2.china electronic System engineering Company,Beijing 100141,china 1. college of electronic {2. and engineering National University of Defense Technology Changsha 410073 China2. China Electronic System Engineering Company Beijing 100141 China

We present a complete and practical analytical model for the IEEE 802.11-based multi-hop wireless *** features of our model are that it first takes into account the realistic problems both from the physical and MAC (Media Access Control) layers in multi-hop wireless networks,including packet collisions,neighboring interference,hidden node problems,capture effects,non-ideal channels,non-saturated situations and multi-rate sending scenarios,which makes the analytical results more ***,it relates the network parameters to the bandwidth requirements of flows and thus is capable of directly analyzing bandwidth-sensitive ***,it provides a 'what-if' analysis,enabling us to predict the performance of the network after a new flow *** on this model,we then present and validate iterative algorithms for end-to-end available bandwidth *** the property of fast convergence and easy realization,these algorithms can give predictive estimates on the change of parameters that will affect the available bandwidth and thus enable us to obtain more accurate available bandwidth information.

关键词： available bandwidth quality of service multi-hop wireless networks IEEE 802.11 network modeling

Terahertz radiation sources based on free electron lasers and their applications

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science china(Information sciences) 2012年第1期55卷 1-15页

作者： TAN Ping1,HUANG Jiang2.LIU KaiFeng2.XIONG YongQian2.FAN MingWu1,2.1Department of electronic and Information engineering,Huazhong University of {2. and Technology,Wuhan 430074,china 2.4} of Electrical and electronic engineering,State Key Laboratory of Advanced Electromagnetic engineering and Technology,Huazhong University of {2. and Technology,Wuhan 430074,china 1. Department of electronic and Information engineering Huazhong University of Science and Technology Wuhan 430074 China2. College of Electrical and Electronic Engineering State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China

The tunability,high power and flexible picoseconds-pulse time structure of terahertz(THz)radiation make the THz free-electron laser(FEL)a very attractive THz source of coherent *** paper focuses on the development and perspectives of THz radiation sources based on the *** principles of the low gain THz FEL oscillator,the SASE THz FEL amplifier and the supperradiant THz FEL are reviewed briefly,and the key technologies of THz FEL,such as injector,accelerator,undulator and optical cavity,are discussed,*** current status of and future prospects for THz radiation sources based on the FEL are emphasized in this *** research and development have shown bright future in free-electron laser(FEL)THz radiation *** potential applications can be carried out in the field of imaging,material research,biology medicine,communication,diagnostics and many others.

关键词： terahertz source terahertz applications free electron laser

Cyclostationary Property Based Spectrum Sensing Algorithms for Primary Detection in Cognitive Radio Systems

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Journal of Shanghai Jiaotong university(science) 2009年第6期14卷 676-680页

作者：岳文静郑宝玉孟庆民 Department of electronic engineering Shanghai Jiaotong University Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications

To implement the primary signal without interference in cognitive radio systems, cognitive radios can detect the presence of the primary user in low SNR. Currently, energy detector is the most common way of spectrum sensing because of its low computational complexity. However, performunce of the method will be possibly degraded due to the uncertainty noise. This paper illustrates the benefits of one-order and two-order cyclostationary properties of primary user＇s signals in time domain. These feature detection techniques in time domain possess the advantages of simple structure and low computational complexity comparing with spectral feature detection methods. Furthermore, performance of the one-order and two-order feature detection is studied and the analytical results are given. Our analysis and numerical results show that the sensing performance of the one-order feature detection is improved significantly comparing with conventional energy detector since it is robust to noise. Meanwhile, numerical results show that the two-order feature detection technique is better than the one-order feature detection. However, this benefit comes at the cost of hardware burdens and power consumption due to the additional multiplying algorithm.

关键词： cognitive radio spectrum sensing cyclostationary feature detection

Effects of NaNbO_3-Co_2._3 Co-additive on the Properties of PZN-PZT Ceramics

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Journal of Wuhan University of Technology(Materials science) 2007年第4期22卷 722-724页

作者：邓毅华 college of Material science and {2. South China University of Technology Department of electronic science and Technology Huazhong University of Science and TechnologyWuhan 430074China

NaNbO3-Co2.3 co-added PZN-PZT （PZCNNT） ceramics were prepared using conventional solid state reaction. The piezoelectric and dielectric properties were measured. The experimental results show that the addition of 0.3mo1% Co2.3 leads to low dielectric loss （tgδ） in PZCNNT ceramics and the proper addition of NaNbO3 not only improves piezoelectric properties but also decreases intensively dielectric loss and mechanical loss. The optimal ceramic having d33=310 pC/N, kp=0.59, εr=985, tgδ=0.0034, Qm=1380 was obtained.

关键词： PZN-PZT piezoelectric constant dielectric constant dielectric loss

Robust multiuser MIMO scheduling algorithms with imperfect CSI

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science china(Information sciences) 2012年第4期55卷 815-826页

作者： MAO JunLing 1,3,GAO JinChun 1,3,LIU YuanAn 1,3,XIE Gang 2.3 & ZHANG Jian 1,3 1 School of electronic engineering,Beijing University of {2. and telecommunications,Beijing 100876,china 2.School of Information and Communication engineering,Beijing University of {2. and telecommunications,Beijing 100876,china 3 Key Lab of Universal Wireless Communications,Ministry of Education,Beijing University of {2. and telecommunications,Beijing 100876,china 1. School of electronic engineering Beijing University of Posts and Telecommunications Beijing 100876 China3. Key Lab of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China2. School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Robust multiuser multiple-input-multiple-output (MIMO) scheduling algorithms are proposed in this *** imperfect channel state information (CSI),traditional scheduling algorithms for the multiuser MIMO system based on the zero forcing precoding scheme will lose some performance due to the multi-user interference (MUI).In order to improve the system average throughput,we study the robust multiuser MIMO scheduling problem with imperfect *** the average capacity formula,we derive a robust factor which can transform the robust multiuser MIMO scheduling problem into the traditional one,thus most existing non-robust scheduling algorithms can be robust if this factor is *** results show that compared with the traditional algorithms,the proposed robust algorithms can improve the system average throughput significantly under the CSI error environment.

关键词： multiuser MIMO (MU-MIMO) scheduling robust imperfect CSI