Method for array gain and phase uncertainties calibration based on ISM and ESPRIT

A now method for array calibration of array gain and phase uncertainties, which severely degrade the performance of spatial spectrum estimation, is presented. The method is based on the idea of the instrumental sensors method (ISM), two well-calibrated sensors are added into the original array. By applying the principle of estimation of signal parameters via rotational invariance techniques (ESPRIT), the direction-of-arrivals (DOAs) and uncertainties can be estimated simultaneously through eigen-decomposition. Compared with the conventional ones, this now method has less computational complexity while has higher estimation precision, what's more, it can overcome the problem of ambiguity. Both theoretical analysis and computer simulations show the effectiveness of the proposed method.     

Unique synthesis of graphene-based materials for clean energy and biological sensing applications

Graphene has unique physical properties,and a variety of proof-of-concept devices based on graphene have been demonstated.A prerequisite for the application of graphene is its production in a controlled manner because the number of graphene layers and the defects in these layers significantly influence transport properties.In this paper,we briefly review our recent work on the controlled synthesis of graphene and graphene-based composites,the development of methods to characterize graphene layers,and the use of graphene in clean energy applications and for rapid DNA sequencing.For example,we have used Auger electron spectroscopy to characterize the number and structure of graphene layers,produced single-layer graphene over a whole Ni film substrate,synthesized well-dispersed reduced graphene oxide that was uniformly grafted with unique gold nanodots,and fabricated graphene nanoscrolls.We have also explored applications of graphene in organic solar cells and direct,ultrafast DNA sequencing.Finally,we address the challenges that graphene still face in its synthesis and clean energy and biological sensing applications.     

微波多普勒雷达海浪参数提取算法

根据海浪混合表面散射理论和线性波理论,利用3种规模波对微波多普勒谱的不同贡献,推导出海浪谱与径向速度转换函数,得到了一种适用于多普勒雷达的海浪谱以及海浪参数提取算法．该算法从海洋回波的多普勒谱中获取径向速度序列,根据海浪速度谱与海浪谱之间的转换关系推导海浪谱,再用谱矩法计算相应的海浪参数．运用该算法分别对微波多普勒谱雷达的模拟与实测数据进行处理,实现了有效浪高和平均海浪周期的高精度提取,证实了该算法在微波段多普勒雷达的海浪参数反演中的准确性．     

反潜CGF系统中吊声传感器的建模方法

提出一种计算机生成兵力(CGF)系统中传感器模型的建模方法。以声纳方程为基础,综合考虑海洋环境及目标声特性,分别建立主、被动式的吊声传感器模型。利用海洋环境数据训练径向基神经网络(简称RBF网络),实时解算不同环境参数时的噪声级。在主动式吊声模型中,考虑声纳的波束方向,便于对目标进行定向等运动分析。通过MATLAB仿真,验证此模型的性能指标优于现有模型的性能,有效为反潜CGF系统服务。     

海洋环境监测中的光纤化学／生物传感技术

通过光纤溶解氧、pH、湿度等化学传感探头及发光菌水质毒性监测生物传感探头的研制,开发出了一类能用于环境监测的新型传感器。其创新之处在于传感探头的设计与包装,以及数种可逆性、选择性、稳定性、使用寿命、响应时间、灵敏度等响应特性具佳的化学及生物传感膜的配方和制作技术。利用这些技术,通过对光纤探头的设计与包装,可以实现在现场及实验室模拟条件下对样品的选择性检测。研制的传感器能广泛应用于海洋污染调查、内河水质评价、水产养殖、工矿企业水气排污自检等诸多方面。     

视觉系统在窄间隙焊缝自动跟踪的研究

本文论述了一种经济有效的视觉系统的研究及其在窄间隙 TIG 焊接中焊缝自动跟踪的应用。该系统以 IBM-PC AT 为主机带有图像存取扩充板,用 CCD 摄像机摄取电弧区域及焊接坡口的图像,然后把它数字化,化为具有7位(即128级)灰暗度的256×256个像点(成像素),并存入图像存取板。IBM PC 对获得的数字图像进行实时图像处理,应用了寻边及模板耦合两种方法所得到的视觉信息被反馈到焊接控制器进而对焊接过程进行有效的焊缝自动跟踪。     

射手-机枪相互作用关系的研究

为了对抵肩射击时射手与机枪之间相互作用关系进行定量研究,该文首次提出了通过理论和实验建立射手系统数学模型的方法,从而也为进一步包括射手在内的机枪系统动力学问题打下了必要的基础。实例结果证明了该文所提方法的正确性和有效性。     

生物碱－半导体场效应传感器的研制及应用

研制了生物碱（秋水仙碱或毛果芸香碱）－半导体场效应传感器，并测得了器件的浓度线性范围：２．５０×１０－５～４．００×１０－３ｍｏｌ／Ｌ（秋水仙碱）；９．９０×１０－５～５．０５×１０－３ｍｏｌ／Ｌ（毛果芸香碱）．该传感器可应用于药物制剂中秋水仙碱的测定．方法简便，效果良好．     

提高磁光大电流传感器动态范围的探讨

在简述磁光大电流传感器原理的基础上，提出了用软件方法；通过非线性校正和程控放大扩展该传感器动态范围的新方法，并给出了实验室测试结果。     

基于梯形波反电动势的BLDCM霍尔位置矫正策略

主要阐述了一种无刷直流电机(BLDCM)的霍尔传感器位置在线矫正策略.传统的BLDCM的霍尔传感器的矫正方式多为直接在电机本体上移动霍尔传感器,这种方式需要拆卸电机,因而在电机调试过程中是相当复杂的.本文主要通过母线电压和母线电流来获取电机换相过程的时间,确定霍尔位置传感器的最优超前角,达到在线修正霍尔位置的目的.最后以含3个霍尔位置传感器的三相两导通模式的BLDCM为仿真对象,并通过Matlab仿真平台对所提出策略加以验证,仿真结果证明该策略能够有效地在线修正霍尔位置偏移角,使得电机的相电流趋于平稳并达到正常运行模式,最后证实了方案的可行性与有效性.