三波长叠加分光光度法测定微量钯的研究

报道以2(3,5二氯2吡啶偶氮)5二甲氨基苯胺(简称为3,5diClPADMA)为显色剂,应用三波长叠加分光光度法测定微量钯的新方法。在002～16mol·L-1的H2SO4介质中,钯与试剂形成稳定的1∶1绿蓝色配合物,其在621和574nm有两个强弱不等的正吸收峰,在434nm处有一负吸收峰。3个峰的吸光度绝对值之和与钯浓度线性相关,钯浓度在0～12mg·L-1范围内符合比尔定律,表观摩尔吸光系数高达203×105L·mol-1·cm-1,比单波长法提高1倍。大量的有色金属及其它贵金属离子不干扰测定。所拟方法操作简便,灵敏度高,选择性好,用于钯精矿、合金及含钯分子筛中微量钯的直接测定,结果满意。     

地震作用下高层建筑结构的重叠分散控制研究

针对地震作用下高层建筑结构大系统控制问题,引入分散控制的策略,导出重叠分散最优控制(Overlapping Decentralized Optimal Control)算法。该方法将包含原理与线性二次型(Linear Quadratic Regulator)最优控制原理相结合,通过扩展分解控制系统及协调收缩获得重叠分散控制器。对某20层钢结构Benchmark结构模型进行数值计算与分析,结果表明,导出的重叠分散最优控制方法可以有效地抑制结构地震反应,控制效果不仅接近传统的集中控制方法,而且提高了高层结构大系统控制的鲁棒性和可靠性。本文方法可应用于大尺度高层结构振动控制中,实现高层建筑结构地震反应的可靠控制。     

基于积分渐进展开的气相色谱重叠峰快速解析法

论文提出用积分渐进展开解析气相色谱重叠峰,该方法有3个主要步骤：首先将谷峰或肩峰分成两个积分区域,得到一个子区域的积分方程和一个重叠峰面积的代数方程;然后用数值积分求出这两个方程计算中所需要的峰面积,再用积分渐进公式将积分方程展开成代数方程;最后,将这两个方程与峰高约束方程联立后,得到一个非线性代数方程组,用Gauss-Seidel迭代可以快速求解方程组,方程收敛的最大迭代次数不超过20次。仿真和实验结果表明,解析的峰高和峰面积误差均很小,峰面积最大误差低于6.44%,峰高的最大误差约为6.80%。由于该算法精度高,效率高,所以这个方法可以用于气相色谱重叠峰和一般色谱峰的实时在线解析。     

Research on Community Structure in Bus Transport Networks

We abstract the bus transport networks (BTNs) to two kinds of complex networks with space L and space P methods respectively. Using improved community detecting algorithm (PKM agglomerative algorithm), we analyze the community property of two kinds of BTNs graphs. The results show that the BTNs graph described with space L method have obvious community property, but the other kind of BTNs graph described with space P method have not. The reason is that the BTNs graph described with space P method have the intense overlapping community property and general community division algorithms can not identify this kind of community structure. To overcome this problem, we propose a novel community structure called N-depth community and present a corresponding community detecting algorithm, which can detect overlapping community. Applying the novel community structure and detecting algorithm to a BTN evolution model described with space P, whose network property agrees well with real BTNs', we get obvious community property.     

影响柱形微腔回音廊模激光抽运阈值能量的因素

将石英光纤浸入染料溶液中形成圆柱形微腔,并采用近轴向消逝场抽运的方式,激发染料溶液的激光增益。柱形微腔回音廊模(WGM)激光抽运阈值能量的高低与抽运激光的消逝场和回音廊模消逝场的空间重叠程度有直接关系,同时也需要考虑低阶与高阶回音廊模损耗的影响。通过改变染料溶液的折射率以及光纤直径,来改变回音廊模的消逝场分布,从而改变两种消逝场空间重叠的体积以及回音廊模的损耗。实验结果表明,柱腔直径不变时,存在一个最佳的溶液折射率值;同时,溶液折射率不变时,也存在一个最佳的柱腔直径,使得一阶回音廊模激光抽运阈值能量最低。     

一种叠前时间偏移并行模式的流水线改进方法

为了隐藏IO和通信延迟进而提升克希霍夫积分叠前时间偏移并行模式的性能,采用了一种流水线改进方法.针对某克希霍夫叠前时间偏移并行模式实例,提出了2种基于该改进方法的原型的设计与实现,从而提高了该实例性能.通过对典型偏移作业实验结果的分析,验证了该方法的有效性.     

X‐ray fluorescence determination of Cs,Ba, La,Ce, Nd,and Ta concentrations in rocks of various composition

The technique has been developed for the quantification of small tantalum, cesium, barium, lanthanum, cerium, and neodymium concentration in rocks with X‐ray wavelength dispersive spectrometer S8 TIGER (Bruker AXS, Germany). The optimum conditions have been chosen for registration of the analyzed elements characteristic radiation and background positions. To determine the concentrations of analyzed elements accurately, the contribution of overlapping lines to the experimental intensities of the analytical lines has been taken into account. The sample of mass about 1.2 g has been pressed into pellet by the hydraulic press. Metrological studies showed that the accuracy in the determination of the concentration of analyzed elements for the developed technique meets the requirements for methods of III accuracy class. The Ta detection limits calculated for TaL_β1‐analytical and CsL_α1‐analytical lines were 2.6 and 3.4 ppm, respectively. The detection limit of Ba, La, Ce, and Nd was (in ppm), respectively, 4.3, 2.7, 5.8, and 4.7. The metrological characteristics of the previously developed and adapted techniques were compared. Ta concentration in granite pegmatite samples has been quantified. The samples of the highest tantalum content have been investigated additionally by powder diffraction and X‐ray microprobe analysis. The X‐ray diffraction method turned out to be insensitive to the detection of mineral phase of tantalum niobates, while micro‐XRF allowed detecting its presence in tourmaline grains. Copyright © 2017 John Wiley & Sons, Ltd.     

高分辨率遥感图像SIFT和SURF算法匹配性能研究

遥感图像匹配是图像校正、拼接的基础。由于遥感图像特征相似度大,重叠区域小,遥感图像对匹配算法的要求更高。本文首先从特征检测、特征描述和特征匹配三个方面,比较了SIFT算法和SURF算法在计算速度和准确度方面性能,然后研究了算法对遥感图像重叠度、度量距离的要求,并针对SURF算法对特征方向误差敏感的特点,提出一种oSURF算法;最后利用卫星1A级条带遥感图像分析各个算法优劣性。测试结果表明,相比于SIFT算法,SURF算法计算速度为SIFT的3倍,需要的图像重叠宽度仅为1.25倍描述向量尺寸,而在保证同样匹配率的情况下,SIFT算法则需要图像重叠宽度为1.5倍描述向量尺寸。本文提出的oSURF算法在保证计算速度的同时,准确度相对于SURF算法提升5%~10%,因此,oSURF算法更适合1A级条带遥感图像的拼接。     

A parallel two-level finite element method for the Navier-Stokes equations

Based on domain decomposition, a parallel two-level finite element method for the stationary Navier-Stokes equations is proposed and analyzed. The basic idea of the method is first to solve the Navier-Stokes equations on a coarse grid, then to solve the resulted residual equations in parallel on a fine grid. This method has low communication complexity. It can be implemented easily. By local a priori error estimate for finite element discretizations, error bounds of the approximate solution are derived. Numerical results are also given to illustrate the high efficiency of the method.     

免疫算法: 一种新的多组分重叠色谱信号的解析方法

色谱及其联用技术的快速发展使其成为复杂样品分析的重要手段,但在复杂样品分析中仍难以避免多组分色谱信号的重叠。化学计量学利用数学方法对复杂重叠信号进行解析,为复杂样品的色谱分析提供了新的手段。本文对免疫算法研究的近期进展进行了总结,并以具体的实例介绍了其在多组分重叠色谱信号解析方面的应用。