基于盒维数的心音信号分形特征研究

在传统盒维数的基础上,从尺度变化的角度,提出一种计算心音信号时域波形分形维数的新的二进盒维数算法,并给出了算法思想和估算方法;然后用该方法对正常心音和几种典型的病态心音的分形维数进行计算,并对其分形特征进行了研究．研究结果表明：心音信号具有明显的分形特征,分形维数能够反映心音信号的复杂程度,并且能够明显地区分正常心音和病态心音．     

睡眠脑电的分形维数分析

为了研究是否用维数来描述脑功能的复杂程序,我们计算了５例正常人整夜睡眠时不同阶段的ＥＥＧ资料维数。结果显示,随着睡眠深度的增加而维数降低。这一事实和生理概念及其他作者所报道的结果相一致,故我们考虑维数分析在表示脑功能状态上有一定的理论意义。如果我们用简化法来计算维数,此法就有可能实时地应用于临床诊断。     

甘草酸提取的分形维数研究

本文从非线性动力学角度探索了甘草酸浸提过程的混沌性态,提出了浸出物甘草酸质量由扩散项和噪声项两部分组成的模型假设,估算关联维数和甘草酸的浸出均值,对天然植物有效成分的提取及数据资源挖掘具有重要的作用。     

天然黄山松种群格局的分形特征——计盒维数与信息维数

采用计盒维数和信息维数对屏南和寿宁不同群落的天然黄山松(Pinus taiwanensis)种群格局的分形特征进行比较分析.结果表明,天然黄山松种群格局具有分形特征,其计盒维数值在1.299 8～1.862 6之间,不同群落的大小次序为Q3>Q1>Q2>Q4>Q7>Q8>Q5>Q6;信息维数值在1.205 7～1.863 7之间,大小次序是Q3>Q1>Q2>Q4>Q8>Q7>Q5>Q6,屏南天然黄山松近纯林黄山松种群的计盒维数和信息维数均高于寿宁混交林,计盒维数定量描述种群占据水平空间的能力和程度,信息维数揭示种群格局强度的尺度变化及个体分布的非均匀程度,分形维数值的高低与群落环境、种群密度、种群在群落中的优势地位、个体的聚集程度及幼树个体数量等相关.黄山松种群格局分形维数随海拔呈现上下波动变化,1 250～1 270 m是更适生的海拔范围.此外,黄山松种群格局的分形特征存在一定的尺度范围,其拐点尺度是分形范围的下限尺度.     

小叶章种群分布格局的分形特征I计盒维数

应用分形理论（Ｆｒａｃｔａｌ ｔｈｅｏｒｙ）中的计盒维数（Ｂｏｘ－ｃｏｕｎｔｉｎｇ ｄｉｍｅｎｓｉｏｎ）对三江平原小叶章（Ｄｅｙｅｕｘｉａ ａｎｇｕｓｔｉｆｏｌｉａ）种群分布格局特征进行了研究。结果表明：三江平原小叶章种群分布格局具有分形特征。其计盒维数５－９月分别为１．５２４、１．７６９、１．７１１、１．６１５、１．７０１,表明其占据空间能力较强。季节动态自５月始至６月达到极大值,而后逐渐下降,     

小叶章种群分布格局的分形特征Ⅱ信息维数与关联维数

应用分形理论中的信息维数（Ｉｎｆｏｒｍａｔｉｏｎ ｄｉｍｅｎｓｏｉｎ）和关联维数（Ｃａｒｒｅｌａｔｉｏｎ ｄｉｍｅｎｓｏｉｎ）研究了三江平原小叶章（Ｄｅｙｅｕｘｉａ ａｎｇｕｓｔｉｆｌｏｉａ）种群分布格局特征。结果表明,信息维数在５～９月分别为１．４９４、１．７０９、１．６４２、１．５５３、１．６２５,表明其结构较复杂,格局强度较高。关联维数则为１．６６２、１．８６１、１．７６６、１．７５０、１．     

两种分形维数在颞下颌关节音分析中的应用

颞下颌关节（TMJ）是人体最复杂的关节之一,有着复杂的生理功能,颞下颌关节音（颚开合时TMJ产生的声音）含有丰富的有关TMJ状态的信息。利用非线性动力学的混沌与分形理论对健康人和颞下颌关节内紊乱（TMD）患者的TMJ音信号进行了分析。分别计算其波形维和相关维。结果表明,健康人TMJ音信号的两种分形维数值都明显高于TMD患者。提示,以TMJ音信号的分形维数值作为TMJ损伤及病变的一个指标是有意义的。     

兴安落叶松种格局的分形特征：计盒维数

分形维数是分形体填充空间程度的度量,种群格局计盒维数能够揭示出种群格局的空间占据程度及其尺度变化规律,拐点尺度指示出个体聚集尺度。本应用计盒维数对大兴安岭主要森林类型中兴安落叶松种群空间格局进行的研究表明,兴安落叶松种群格局均具有统计自相似性。各类兴安落叶松林中兴安落叶松种群格局具有较高的计盒维数（＞１．５,接近２）,对空间占据程度较高,建群和优势地位明显,空间占据程度的强弱次序为越桔－兴空落叶     

桂花叶片的分形特征

提供了一种叶片分形维数的测定方法,并用其测定了桂花(Osmanthus fragrans Lour)的叶片分形维数。通过分析发现：(1)桂花叶片具有典型的分形特征并且这种分形特征可以用分形理论的一般方法加以研究;(2)同一株桂花树的成熟叶片在统计意义上具有相同的分形维数;(3)对于桂花这个物种的成熟叶片在统计意义上具有相同的分形维数。由此推测同一种植物的成熟叶片(或者其他构件)具有相同分形维数。最后提出创建植物分形分类学的设想。     

兴安落叶松种群格局的分形特征信息维数

种群格局信息维数能够刻划格局强度的尺度变化程度,揭示出种群个体分布的非均匀性状况。采用信息维数对大兴安岭兴安落叶松种群格局的研究显示,各类兴安落叶松林中兴安落叶松种群格局的信息维数大小依次为越桔－兴安落叶松林（１．４８０）＞杜香－兴安落叶松林（１．３７３）＞杜鹃－兴安落叶松林（１．３２１）＞草类－兴安落叶松林（１．０９３）。虽为群落建群种,兴安落叶松种群格局的信息维数较低（＜１．５,远离２）,格局     

后河自然保护区珍稀濒危植物种群分布格局的分形特征：计盒维数

通过4种优势树种和7种珍稀树种种群的计盒维数来反映种群分布格局的分形特征．结果表明,4种优势种群的计盒维数在1．346-1．414之间,在历研究的整个常绿落叶阔叶混交林群落中占据了较大的生态空间;其中尖连蕊茶种群的计盒维数最大,占据最大的生态空间．而7种珍稀树种种群的计量续数除了金钱槭种群大于1之外,其余6个种群的计盒维数都小于1,说明它们占据生态空间的能力较小．并且这11个种群的拐点尺度都出现在5-12．5m之间．根据分形的自相似性,可以推断种群在大于拐点尺度的所有尺度上都为同一分布类型,并且在拐点前后种群的格局类型夏发生变化．种群分布格局的判定结果部分地验证了这一观点,11个物种中有5个物种的种群格局在拐点前后发生变化,另6种没有发生这种变化。     

A New Method for Calculating Net Reproductive Rate from Graph Reduction with Applications to the Control of Invasive Species

Matrix models are widely used for demographic analysis of age and stage structured biological populations. Dynamic properties of the model can be summarized by the net reproductive rate R ₀. In this paper, we introduce a new method to calculate and analyze the net reproductive rate directly from the life cycle graph of the matrix. We show, with examples, how our method of analysis of R ₀ can be used in the design of strategies for controlling invasive species.     

两种PCR方法对检测A组轮状病毒膜芯片杂交结果的影响

A组轮状病毒(rotavirus,RV)是导致拿世界婴幼儿腹泻的最主要病原,危害巨大。拟用RT-巢式PCR技术对A组RV的保守序列进行高度扩增,通过固本室内制的膜芯片杂交,实现对该病毒的检测。分别采用对称PCR和不对称PCR扩增,均可得到扩增的目的片段．对称式扩增产物杂交结果不理想。而不对称式扩增得到了大量待检单链产物,同膜芯片杂交获得了理想的杂交结果。显著地提高了对A组RV杂交检测的灵敏度。表明不对称式PCR扩增是一种制备用于芯片杂交大量单链产物的理想方法,尤其是针对富含AT的核酸检测区域。     

New methods for the assessment of mite numbers and results obtained for several textile objects

Summary The assessment of mite numbers in textile objects is important with regard to measures aimed at mite control. The standard method is to take a dust sample and to separate the mites from the dust by means of flotation. The results of mite assessment can be improved using methods based on the natural mobility of the mites; the so-called Mobility Test makes use of the intrinsic movement tendencies of the mites, whereas the Heat Escape Method uses the mobility of the mites in connection with the effects of heat. An example concernig two jackets shows the difference in results of mite assessment when using the conventional method (dust sample and flotation) on the one hand, and the new methods (Mobility Test and Heat Escape Method) on the other. It is shown that the conventional method can only supply relative mite numbers. The new methods also enable the user to monitor more efficiently the use of acaricide agents in mite control. This is demonstrated using the example of two beds and a carpet taken from a children's bedroom. The considerably higher numbers of mites suggest that the risk of the occurence of mite allergens and their penetration into the indoor air is even greater than previously assumed.     

Comparison of Two New Robust Parameter Estimation Methods for the Power Function Distribution

Estimation of any probability distribution parameters is vital because imprecise and biased estimates can be misleading. In this study, we investigate a flexible power function distribution and introduced new two methods such as, probability weighted moments, and generalized probability weighted methods for its parameters. We compare their results with L-moments, trimmed L-moments by a simulation study and a real data example based on performance measures such as, mean square error and total deviation. We concluded that all the methods perform well in the case of large sample size (n>30), however, the generalized probability weighted moment method performs better for small sample size.     

Inheritance of the Morphological Differences between Maize and Teosinte: Comparison of Results for Two F(2) Populations

Molecular marker loci (MMLs) were employed to map quantitative trait loci (QTLs) in an F(2) population derived from a cross of maize (Zea mays ssp. mays) and its probable progenitor, teosinte (Z. mays ssp. parviglumis). A total of 50 significant associations (putative QTLs) between the MMLs and nine key traits that distinguish maize and teosinte were identified. Results from this analysis are compared with our previous analysis of an F(2) population derived from a cross of a different variety of maize and another subspecies of teosinte (Z. mays ssp. mexicana). For traits that measure the architectural differences between maize and teosinte, the two F(2) populations possessed similar suites of QTLs. For traits that measure components of yield, substantially different suites of QTLs were identified in the two populations. QTLs that control about 20% or more of the phenotypic variance for a trait in one population were detected in the other population 81% of the time, while QTLs that control less than 10% of the variance in one population were detected in the other population only 28% of the time. In our previously published analysis of the maize X ssp. mexicana population, we identified five regions of the genome that control most of the key morphological differences between maize and teosinte. These same five regions also control most of the differences in the maize X ssp. parviglumis population. Results from both populations support the hypothesis that a relatively small number of loci with large effects were involved in the early evolution of the key traits that distinguish maize and teosinte. It is suggested that loci with large effects on morphology may not be a specific feature of crop evolution, but rather a common phenomenon in plant evolution whenever a species invades a new niche with reduced competition.     

Alternative Gramineous Hosts of Leptosphaeria nodorum Including Two New Records for the U. S. A.

Repeated trunk injections of tetracycline hydrochloride and oxytetra-cycline over a 27 month period, retarded the rate at which clove trees in Zanzibar, died from sudden death (SD) disease. This result provides additional support for an MLO aetiology for SD, but indicates that the tetracycline formulations and method of application, as described here, is not a feasible method of SD control in the field. Bioassay of leaf discs and root sections using agar plates seeded with Bacillus subtilis, at various times after injection, indicated that antibiotic distribution to the canopy was extensive, but that down to the roots was minimal. The proportion of leaf discs showing tetracycline activity declined over a 54 day period post-injection, from 75,% to 17%. Mean tetracycline levels in leaves per tree peaked at 2.4 μg/ml, 21 days after injection. The highest individual leaf disc level was 7 μg/ml. Most trees maintained concentrations of tetracycline inhibitory to B. subtilis growth for 2,1–41 days.