MIMO系统中互耦影响分析

文章简要概括了MIMO系统及其信道容量，并基于矩量法重点分析了MIMO系统中天线阵元间的互耦作用对每个天线阵元辐射方向图的影响。结果表明互耦能使每个天线阵元的方向图发生畸变，所以在应用射线追踪法构建MIMO系统的信道矩阵时必须考虑互耦的影响以提高计算精度。     

Design and Implementation of An Active Multibeam Antenna System with 64 RF Channels and 256 Antenna Elements for Massive MIMO Application in 5G Wireless Communications

This paper focuses on the design and implementation of an active multibeam antenna system for massive MIMO applications in 5G wireless communications. The highly integrated active multibeam antenna system is designed and implemented at 5.8 GHz with 64 RF Channels and 256 antenna elements. The 64-channel highly integrated active multibeam antenna system provides a verification platform for digital beamforming algorithm and massive MIMO channel estimation for next generation wireless communications.     

激光等离子体产生条件的实验研究

用时间和空间分辨光谱诊断法研究了激光轰击Ｔｉ靶产生的等离子体发射光谱,测得了等离子体形成的时间,与理论符合很好;通过对不同背影气体压强环境中等离子体羽的飞行速度和电子温度的计算。讨论了背景气体在激诱导等离子体形成中的作用。     

Speaker adaptation technique for HMM model

A new speaker adaptation technique for the hidden Markov model (HMM) based on the maximum model distance (Kwong, 1998; He, 1999) approach is presented. Experimental results have shown that this technique provides good performance even with a small amount of adaptation data. When these results are compared with those from the Baum-Welch approach and the stochastic matching approaches (Sank, 1996), it is found that the presented approach provides the best performance     

Performance of thin-film transistors with ultrathin Ni-MILCpolycrystalline silicon channel layers

High-performance, low-temperature processed thin-film transistors (TFTs) with ultrathin (30-nm) metal induced laterally crystallized (MILC) channel layers were fabricated and characterized. Compared with the MILC TFTs with thicker (100 nm) channel layers, the ones with the 30-nm channel layers exhibit lower threshold voltage, steeper subthreshold slope, and higher transconductance. Furthermore, the comparatively lower off-state leakage current and the higher on-state current of the “thin” devices also imply a higher on/off ratio. At a drain voltage of 5 V, an on/off ratio of about 3×10 ⁷ was obtained for the 30-nm TFTs, which is about 100 times better than that of the 100-nm TFT's. No deliberate hydrogenation was performed on these devices     

A dual-passband filter of canonical structure for satellite applications

Due to the complex arrangement of frequency plans and spatial coverages in modern satellite communication systems, channels that are noncontiguous in frequency may be amplified by a single power amplifier and transmitted to the ground through one beam. In this letter, a dual-mode canonical filter with dual-passband is presented. The filter adopts dual-mode technique for mass and volume reduction. Canonical structure is adopted for maximum zero realization. To validate the design technique, a six-pole dual-mode dual-passband filter of canonical structure for Ka-band (30/20GHz) satellite transponder is realized. The measured frequency response of the filter shows good agreement with the computed one.     

肾脏鳞状细胞癌一例电镜观察

用电镜方法观察了一例已经甲醛固定的肾肿瘤标本,以明确诊断。发现光镜下所见的肿瘤组织内横纹肌肉瘤样细胞,电镜下可见其胞浆内有较多的张力原纤维,未见肌丝,癌细胞间可见成串的桥粒。电镜诊断为（肾脏）鳞状细胞癌。     

Memristor-based genetic algorithm for image restoration

This paper explores a way of deploying the classical algorithm named genetic algorithm (GA) with the memristor. The memristor is a type of circuit device with both characteristics of storage and computing, which provides the similarity between electronic devices and biological components, such as neurons, and the structure of the memristor-based array is similar to that of chromosomes in genetics. Besides, it provides the similarity to the image gray-value matrix that can be applied to image restoration with GA. Thus, memristor-based GA is proposed and the experiment about image restoration using memristor-based GA is carried out in this paper. And parameters, such as the size of initial population and the number of iterations, are also set different values in the experiment, which demonstrates the feasibility of implementing GA with memristors.¹     

基于TDLAS的非均匀流场温度分布的测量

基于可调谐半导体激光吸收光谱（TDLAS）温度测量技术,使用多条谱线能够实现非均匀流场的气体温度分布的测量,主要有剖面拟合和温度离散两种方法。对剖面拟合方法进行理论分析和仿真,并且假设电炉上方0.5 cm处的温度分布为二次函数ax2+bx+c,采用剖面拟合方法进行测量,与热电偶测量的温度进行对比,温度最大波动为49 K。     

基于DWT变换的语音信息隐藏技术研究

本文基于小波域低频系数模数运算,提出了一种将数字水印隐藏在公开语音中的语音信息隐藏算法.我们将降维处理后的二值水印嵌入到音频信号的低频小波系数中,然后对低频小波系数进行模数运算,并根据运算结果对音频系数值进行修改,嵌入水印.提取时按照同样方法,将音频信号小波分解得到的低频系数进行模数运算,升维后得到提取水印.仿真实验表明,该水印算法在噪声、滤波、重量化和重采样等攻击时具有较好的鲁棒性.