针对多目标的分布式多边融合定位

针对基于接收信号强度指数(Received Signal Strength Indicator,RSSI)的多目标定位问题,结合点估计与椭圆估计算法,提出一种新的分布式多边融合定位(Distributed Multi-lateral Fusion Localization,DMFL)算法.首先,通过多边定位算法进行粗定位,估计目标的大致位置.其次,基于区间分析理论在线获取泰勒展式高阶余项的边界,并通过集员递归算法求解多目标定位问题.最后,通过实验和仿真验证该算法的定位性能.结果表明,在相同的节点布置条件下,与最新的RSSI定位算法相比,该算法的定位精度更高,最大误差小于0.3 m,并可提供保证包含目标真实位置的最优区域.     

基于信号经验模态分解与分集合并的齿轮故障诊断

为了准确地进行齿轮故障诊断,结合信号经验模态分解与分集合并,提出了一种新的故障诊断方法;首先,运用经验模态分解对齿轮振动信号进行分解得到若干个分量;其次,根据分量的峭度大小以及相邻分量的峭度是否接近,筛选、合成有效分量;然后,运用等增益分集合并技术对有效分量进行合并,即将其包络进行叠加;接着,使用快速傅立叶变换得到信号包络和的频率谱;最后,根据该频率谱进行故障诊断;通过对仿真信号和齿轮断齿故障振动信号的分析,验证了方法的有效性.     

Mathematical Advancement of General Chlorine Bulk Decay Model

An accurate chlorine bulk decay model is needed to ensure that potable water meets the microbial and the chemical safeties at the treatment plant and throughout the distribution. Among the mathematical models available,the general second-order chlorine bulk decay model( GBDM) is the most fundamentally sound.Application of the GBDM,however,has been hindered by its numerous fictive parameters and lack of an analytical solution. This theoretical work removes the two obstacles. The GBDM is solved through transformation and integration. The analytical solution provides deep insights into the GBDM and facilitates the parameterization and sensitivity analysis. The background natural organic matter( NOM) is characterized with the probabilistic distribution of functional groups. It reveals that the mean of the function group distribution is correlated with the initial chlorine decay rate coefficient( κ_0). A simple formula is developed to determine κ_0 directly from the initial chlorine decay. The theoretical treatment reduces the fictive parameters to a minimum. For the common lognormal distribution,the GBDM needs only three parameters,well defined as initial chlorine demand X_0,median rate coefficient km,and heterogeneity index σ. For more complicated scenarios,composite distributions are constructed through superposition of individual distributions. A highlighted example is to predict chlorine decay in blends of different waters. With the theoretical and mathematical advancement here,the GBDM can be applied effectively to any reactive background matter in any reaction systems.     

三种基本放大电路分析与比较

模拟电路中三种基本放大电路是教学的重要内容,其应用非常广泛,它是构成其它多级放大电路的基础。本文对共发射极、共集电极、共基极三种基本放大电路的静态和动态进行了分析,同时对它们的特点及用途进行了比较。     

酞菁铜薄膜光电晶体管的制备与特性

无机光敏器件难于做成大面积光电传感器,且其生产成本高、工艺复杂,而有机光敏器件多采用二极管或平面场效应三极管结构,导致光电流增益小或驱动电压较大.针对这些问题,提出一种新的器件结构.采用真空蒸镀和溅射的方法,制备了结构为氧化铟锡(ITO)/酞菁铜(Cu Pc)/铝(Al)/酞菁铜(Cu Pc)/铜(Cu)的有机光电晶体管.对器件的光电特性进行了测试分析,结果显示晶体管的I-V特性表现出显著的不饱和特性和光敏特性.当发射极集电极偏压为3 V时,器件无光照时电流放大系数为16.5,当625 nm光照射时的电流放大系数为266.2.     

无线随钻测斜仪故障分析与解决办法

无线随钻测斜仪在现场施工中最受关注的故障是仪器不产生脉冲信号。仪器无脉冲信号可能是泥浆泵排量低、仪器座键不到位和仪器工作环境等因素产生的仪器井口测试无信号;可能是仪器脱键、钻井液液量不够以及仪器本身原因造成的仪器下钻中途测试和井底开泵测试无信号;还可能是电池剩余电量少或有强电流等干扰源引起的仪器工作中途无信号或信号弱等。现场施工中,应综合考虑所有的相关因素,准确地判断出出现问题的真正原因,并采取相应的解决方法,以减少不必要的起下钻。     

突变型P53特异性活化T细胞的诱导与扩增

采用多种细胞因子诱导外周血单核细胞分化为成熟的树突状细胞（DC,Dentritic Cell）,将成熟DC与初始T细胞共培养,并连续加入DC刺激从而避免活化的T细胞凋亡。将活化的T细胞转入包被有CD3和CD28抗体的板中,使活化T细胞进一步大量扩增。流式检测多因子诱导后DC表型发现,高表达CD83、CD11c、CD11b、CD80、CD86、CCR7、CD54,低表达CD14、CD3、CD33,说明因子成功诱导单核细胞为成熟DC。流式检测扩增的活化T细胞发现高表达CD3、CD8,含有很低量的调节性T细胞（Treg）,分泌大量的IFN-γ,表明扩增出的细胞中活化T的含量很高,为临床研究提供参考。     

Enhancement of ultrabroadband Bi NIR emission via fluorination for all wavelength amplification of optical communication

Bismuth (Bi)-doped photonic glasses and fibers with broadband near-infrared (NIR) photoemission have potential applications in tunable lasers and broadband amplifiers. Yet, when it comes to all wavelength amplification of optical communication, it remains challenging to achieve efficient Bi NIR emission in the technically relevant C- and L- bands (1530-1625 nm). Here, we propose a scheme by fluorination triggered enhancement of ultra-broadband Bi NIR emission in nitrided germanate glasses. Besides, compared to previous research, a unique and efficient Bi-activated ultra-wideband NIR emission with new emission bands peaked at ~924 and ~1520 nm under excitation of 450 nm are obtained in nitrided germanate glasses after fluorination. Moreover, the fluorination can modulate the local chemical environment by forcing the conversion of aluminum species from AlO₄ to AlO₅ and AlO₆ and consequently increase the flexibility of the glass network structure, which finally induces the conversion of Bi species and then manipulates the relative emission intensity of different Bi NIR centers. Thus, a flat and tunable emission spectrum covering the entire optical communication band is obtained by optimizing the fluoride amount. We believe this work is helpful to design the Bi-doped tunable fiber lasers and ultra-broadband amplifiers for all wavelength amplification of optical communication.     

基于改进的K-means聚类图像分割算法

介绍一种采用K—L变换、二维向量小波和改进的K—means结合的图像分割算法。阐述和分析了二维向量小波变换和Laws纹理能量测度，得出图像每个像素点可用9个纹理特性来描述的结论。运用K—means算法的思想对其进行改进，最后得出分割后的图像。试验结果证明，运用以上处理方法可显著提高分割速度和精度。     

模态声发射——声发射信号处理的得力工具

模态声发射是声发射信号处理技术的得力工具。介绍它在声发射源定位、复合材料损伤源识别、疲劳裂纹萌生和扩展的声发射监测以及日历损伤声发射评价等工程实践中的应用。