4H-SiC MESFET结构外延生长技术

利用热壁式CVD技术生长4H-SiC MESFET结构外延材料,TMA和氮气分别用作p型和n型掺杂源.外延层厚度使用SEM进行表征,SIMS及汞探针C-V用作外延层掺杂浓度测试.通过优化生长参数,成功生长出高质量的MESFET结构外延材料并获得陡峭的过渡掺杂曲线,并给出了部分器件测试结果.     

一种基于薄膜体声波谐振器的高灵敏度质量传感器

介绍了一种针对于生物传感应用的薄膜体声波谐振(thin film bulk acoustic resonator,FBAR)质量传感器.薄膜体声波谐振器谐振频率非常高(能够达到几兆赫兹),同时具有较大的品质因数,基于这种器件的质量传感器具有非常高的质量灵敏度.首次提出了三对全金属的A1-W层作为布拉格声学反射层的FBAR,制备出了固态装配型的FBAR传感器.通过淀积不同厚度Al层顶电极分析了器件的质量灵敏度,仿真得到的质量传感器串联谐振频率在2.8 GHz附近,质量响应度达到5×10-4 ng/Hz//cm2,可以实现分子量级的质量传感.     

Multiuser beamforming based on max SINR for downlink spatial multiplexing MIMO

In this article, a method based on max signal interference noise ratio (SINR) criterion is proposed, to mitigate the interuser interference for downlink multiuser spatial multiplexing multi-input multi-output (MIMO) systems.Unlike the zero forcing (ZF) scheme in which the SNR is decreased when the interference is eliminated completely, max SINR method makes a compromise between noise and interuser interference.When the number of substreams is larger than the difference between the number of base station antennas and the sum of interference mobile station antennas, the ZF is infeasible.An existing coordinated TX-RX block diagonalization (COOR BD) method uses preprocessing at the receiver to cancel the interuser interference.However, it cannot obtain more receive diversity gain because of the preprocessing.Analysis and simulation show that the max SINR scheme has better performance than the ZF method.Moreover, when the ZF is infeasible, the max SINR scheme can obtain more receive diversity gain than COOR BD in the two-user case.     

Realistic face modeling based on multiple deformations

On the basis of the assumption that the human face belongs to a linear class, a multiple-deformation model is proposed to recover face shape from a few points on a single 2D image. Compared to the conventional methods, this study has the following advantages. First, the proposed modified 3D sparse deforming model is a noniterative approach that can compute global translation efficiently and accurately. Subsequently, the overfitting problem can be alleviated based on the proposed multiple deformation model. Finally, by keeping the main features, the texture generated is realistic. The comparison results show that this novel method outperforms the existing methods by using ground truth data and that realistic 3D faces can be recovered efficiently from a single photograph.     

移动IPv6概述

文章分析了IPV6支持移动性的优势，概述了移动IPv6协议，并对一些热点问题，如快速切换、平滑切换、移动管理、AAA和服务质量等进行了探讨。     

噪扰下数字化多频连续波雷达的测距模糊问题

数字化多频连续波测距雷达是一种新体制雷达.它具有能同时测定多个目标、便于同时得到目标多个运动参数等突出优点.为了解决增大最大测距不模糊距离与提高测距精度之间的矛盾,我们将会在多频雷达中采用参差频差关系进行测距,这样我们可以大大提高测距最大不模糊距离.但此时噪声对测距结果有着各种有待讨论的影响,包括:能否正确解模糊;对输入信号信噪比有何要求;理论测距精度有何变化;直至对参差系数有何要求等.数字化多频雷达的这些问题,本文对这些问题进行了详细的讨论,并给出了本文结论的计算机仿真结果.从而在理论上为这种雷达的深入研究提供了一个很好的基础.     

宽带接入服务器的选择配置和应用

本文主要分析了影响宽带接入服务器性能的各种因素，介绍了如何选择宽带接入服务器，并针对REDBACK公司的SMS1800和UNISPHERE公司的ERX1400两种典型宽带接入服务器说明如何进行配置，为应用宽带接入服务器提供参考。     

H原子在Si(111)-7×7表面吸附的STM研究

利用超高真空扫描隧道显微镜(UHV-STM),在液氮(78K)及液氦(4.2K)低温条件下研究了H/Si(111)-7×7吸附体系.H原子易于吸附在表面增原子(adatom)以及剩余原子(rest atom)的位置,导致表面局域电子态密度(LDOS)和STM图像发生明显的变化.利用扫描隧道谱技术(STS)测量获得了H吸...     

Service function chain embedding algorithm with wireless multicast in mobile edge computing network

To resolve the excessive system overhead and serious traffic congestion in user-oriented service function chain (SFC) embedding in mobile edge computing (MEC) networks,a content-oriented joint wireless multicast and SFC embedding algorithm was proposed for the multi-base station and multi-user edge networks with MEC servers.By involving four kinds of system overhead,including service flow,server function sustaining power,server function service power and wireless transmission power,an optimization model was proposed to jointly design SFC embedding with multicast beamforming.Firstly,with Lagrangian dual decomposition,the problem was decoupled into two independent subproblems,namely,SFC embedding and multicast beamforming.Secondly,with the L_p norm penalty term-based successive convex approximation algorithm,the integer programming-based SFC embedding problem was relaxed to an equivalent linear programming one.Finally,the non-convex beamforming optimization problem was transformed into a series of convex ones via the path following technique.Simulation results revealed that the proposed algorithm has good convergence,and is superior to both the optimal SFC embedding with unicasting and random SFC embedding with multicasting in terms of system overhead.     

LMBE法生长Mg0.2Zn0.8O及MSM型紫外探测器的制备

采用激光分子束外延(LMBE)方法在蓝宝石(0001)面生长了高质量的Mg0.2Zn0.8O薄膜,并对薄膜在空气中900℃进行了1h的退火处理,然后采用剥离方法在薄膜表面制作了Al叉指电极,制备出MSM型Mg0.2Zn0.8O光电导紫外探测器.对响应时间的测试表明,探测器的上升时间仅为14.3ns,下降时间为6.5μs.