西南大西洋拉氏南美南极鱼耳石形态的多样性

分析了2011年采自西南大西洋的拉氏南美南极鱼(Patagonotothen ramsayi Regan, 1913)耳石形态特征, 结果显示, 根据耳石后端、主间沟、翼叶及耳石侧表面辐射状条纹等位置存在的明显差异, 可将其耳石分为6种类型。椭圆傅里叶分析所得77个特征系数的单因素方差分析显示, 6种耳石类型两两之间差异显著(P<0.05)的特征系数可达36.4%, 表明6种类型耳石形态间存在较大差异。结合形状指标和椭圆傅里叶分析表明: (1)基于形态特征的耳石类型划分是可行的; (2)结合定量分析和定性分析可以更准确地表达拉氏南美南极鱼耳石类型多样性及其耳石形态特征; (3)椭圆傅里叶分析在拉氏南美南极鱼耳石的形态分类研究中更具优势。根据椭圆傅里叶分析重建的耳石外轮廓直观反映了6种耳石类型的差异所在。6种耳石类型在不同鱼体体长、耳石长度分布区间所占比例不同, 且同一个体的左右耳石也存在一定差异, 检测样本中左右耳石属不同类型的比例达20.2%。Ⅳ型仅出现在小个体中, 表明拉氏南美南极鱼幼体阶段耳石形态为卵圆形, 随生长发育耳石形态则渐变为梭形。各体长组中有多种类型耳石存在, 表明拉氏南美南极鱼在各生长阶段均具有耳石形态多样性。今后开展拉氏南美南极鱼耳石研究时要结合多种耳石类型进行分析, 并兼顾其左右耳石的差异。

     

安徽省地基GPS大气可降水量时空演化特征分析及应用研究

安徽地处梅雨区域,研究此区域的大气可降水量(PWV)时空分布和演化特征对理解水汽相关过程如降雨、蒸发和对流活动等起到重要的作用。笔者分析了安徽地区两个时间段(2012年6月—2012年9月和2014年6月—2014年9月)逐时GPS/PWV资料,揭示了GPS/PWV平均值和地形高度变化存在正相关。相应的GDAS资料积分得到的GDAS/PWV揭示了本区域上层大气中的PWV变化主要集中在地表到700 hPa区间。基于快速傅里叶变换(FFT)得到安徽地区6—9月份PWV具有季节性周期,13.0035天~准2周振荡等多尺度特征。进一步根据季节变化特征得出7月底是GPS/PWV值的关键转折点。最后给出了GPS/PWV和GDAS/PWV在天气预报分析中的应用研究,PWV资料对降水预报能力提高、人工影响天气、空中水资源等分析研究奠定了基础。     

n维Fourier变换及应用

本文给出了n维Fourier变换及其性质,借助于欧拉积分给出了一类高维偏微分方程的古典解。     

n维热传导方程的经典解

给出了n(n＞2)维Fourier变换及其性质,并借助它们及Euler积分给出了一类高维热传导方程的Cauchy问题的经典解.     

Frequency domain analysis and the application for extracting electroencephalogram signal characteristic waves

A new quantitative analysis method to describe the dynamic variation of electroencephalogram (EEG) signals was proposed. Based on the Fourier transformation, the method is called Fourier multi resolution analysis (FMRA). FMRA decomposes the frequency domain with a binary system and can resolve EEG signals into the basic rhythms of the four waves to study the dynamic characteristics of EEG signal rhythms. FMRA has clear physical meaning, and can obtain more information than wavelet multi resolution analysis does. FMRA can extract perfectly the rhythmic characteristics of EEG signals in the time and frequency domains.     

Transverse shape analysis of xylem ground tissues by Fourier transform image analysis I: trial for statistical expression of cell arrangements with fluctuation

Periodic cell arrangements of tracheids in Cryptomeria japonica and Agathis sp., and that of wood fibers in Magnolia obovata were examined by Fourier transform image analysis (FTIA). The angular distribution functions on power spectral patterns (PSPs) transformed from the dot maps were traced. As well as this conventional method, we developed the line convolution method and domain transformation for more correct analysis of radial and tangential arrangements. Cell arrangements became clear in Cryptomeria and Agathis. Fluctuations were expressed by the standard deviation (σ) or the relative standard deviation (σ_r) so that we could compare the characteristics of both woods. In Cryptomeria, the most provable distance between tracheids along radial files was 36.7 µm with 17% fluctuation, whereas the tangential interval was 28.3 µm with σ_r of 24%. In Agathis, the radial diameter was 35.1 µm with σ_r of 23% and the tangential interval was 41.5 µm with σ_r of 23%. In Magnolia, the maximal periodicity of wood fibers was 15.8 µm and 20.5 µm along and between radial files, respectively, although the fluctuations could not be estimated because of the remarkable interruptions by numerous vessels.     

Analytical applications of Fourier transform-infrared (FT-IR) spectroscopy in microbiology and prion research

A genuine biophysical method, Fourier transform-infrared (FT-IR) spectroscopy has become a versatile research tool in biochemistry and biomedicine. Topical applications in microbiology and prion research are impressive illustrations of the vigorous evolution of the technique. FT-IR spectroscopy has established itself as a powerful method for the rapid differentiation and identification of microorganisms, thereby contributing to both clinical medicine and the prevention of bioterrorism. It has also led to considerable progress in various other fields of basic research, not least in prion sciences. In this field, FT-IR spectroscopy has been increasingly applied as a tool for elucidating structural features of the pathological prion protein, and also to study the molecular changes induced by prions in neuronal tissue and blood. This article sets out to give a review of current examples of the analytical potential of FT-IR spectroscopy in microbiology and prion research.     

基于三阶Hanning卷积窗的谐波检测方法研究

为减少谐波分析结果的误差,提出一种基于三阶Hanning卷积窗的谐波分析方法。在用公式详细探讨加窗插值算法原理的基础上,利用Matlab仿真试验验证算法的分析精度。MATLAB仿真结果表明,三阶Hanning卷积窗具有优良的频谱抑制性能,可进行电力谐波的高精度检测。     

大灵猫、小灵猫的直针毛红外光谱比较研究

为了研究动物毛发的红外光谱学特征在动物分类中的应用。使用傅立叶红外光谱(FTIR)对大灵猫和小灵猫的毛发进行了检测和分析。结果表明：2种动物同一根直针毛从毛尖到毛根不同部位间红外图谱存在差异,说明毛发的不同部位都有受同一基因表达控制的角蛋白成份存在,但数量存在差异。2种动物直针毛中部的红外图谱具有明显的种间差异,主要表现在626~655 cm波数范围内大灵猫、小灵猫红外图谱在峰面积和峰值均有明显差异;大灵猫具有异构角蛋白构型,在640.3 cm和646.1 cm位置出现了N-H-基团的伸缩振动M形吸收峰。所以红外光谱是一种检测和分析动物毛发的有效的技术手段,在野生的动物的分类研究中有较好的应用前景。     

浅析线形非时变系统的分析方法

对线性非时变系统的3种分析方法进行了分析和比较,并且对这些分析方法的适用范围及优缺点作了对比．指出了3种分析方法之间的内在联系和区别,通过分析一个RLC电路,说明3种分析方法的具体应用．