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Based on the return map and the principle of closed vectors, a new method is proposed to extract unstable periodic orbits embedded in chaotic attractors. As examples, the UPOs embedded in chaotic attractors of Logistic, Hénon and Lorenz are extracted respectively by this method. And our results of Skewed Hénon map also be compared with Nusse's. These results suggest that this method is valid for unstable periodic orbits from period one to period infinite of arbitrary dimension chaotic system. The dynamic considerations of spiking and UPO coding for individual neuron and neural system under external periodic and chaotic exciting stimulus also be studied in this dissertation. A lot of spiking phenomena, such as synchronization, period, and chaos appear alternatively with the changing of the stimulus frequency. For the small stimulus frequency the neuron could completely convey the periodic signal in synchronous anti-phase into interspike intervals sequences. For the slow time–scale chaotic input, the output two ISI sequences are reciprocally related to input signals, and their oscillation wave shape in time course can be derived from that of the input signals variation, furthermore, the similar input sequence and order of UPOs, distribution of LES and value of KYD remain in attractors reconstructed from ISI sequences.

发现周期信号在单个神经元传递过程中，随着激励频率的改变，神经元输出的峰峰间期interspike interval时间序列呈现出周期、混沌和准周期的交错变化，特别当外加激励信号频率较低时，周期信号可以通过神经元ISI序列以反相同步的周期运动形式传递下去；同时无论是周期还是混沌激励信号，在神经系统中的传递均与其自身强度和神经元之间的耦合强度的大小密切相关；快变时间尺度的混沌激励信号在耦合的神经系统传递过程中，会造成大量基本信息的丢失；而慢变时间尺度的混沌激励信号在神经系统传递中，它的非线性特征信息，如混沌吸引子、不稳定周期轨道、Lyapunov指数谱和分形维数，会通过系统输出的ISI序列部分地重现出来，如与输入慢变时间尺度的混沌激励信号相比，神经系统输出的ISI序列具有：相似几何形状的混沌吸引子、相近的Lyapunov指数谱和分形维数、局部结构相同的不稳定周期轨道的排列方式。

Due to the selenoproteins having the SECIS, we searched and filtered the expressed nucleic acid sequences of Durum Wheat from Genbank to find out the objects with SECIS and 47 object sequences was found aggregately.

鉴于目前已发现的硒蛋白均具有SECIS特征结构，首先对Genbank中的Durum Wheat表达核酸序列进行逐一筛选，找到其具有SECIS的序列，共发现47个具有SECIS特征结构的目标序列。

During the postgenomics era the information about genomic sequence and gene functions provides a new foundation for evolutionary biology and ecology As the first whole-genome sequenced plant Arabidopsis thaliana and its wild relatives have played a critical role in understanding the evolution of genomics and speciation Both A halleri and A lyrata are closely related to the model species A thaliana A halleri ssp gemmifera occurs in northeastern China Japan and Taiwan; while its sister A halleri ssp halleri is mainly distributed in Europe Geographical barriers such as Tienshan Mountain Range isolate these intraspecific sisters Likewise A lyrata ssp kamchatica and ssp lyrata occur in East Asia and North America respectively Such distribution patterns seem to be consistent with allopartic speciation The comparison between ancestral and extant polymorphism by multilocus can be informative about the population genetics of speciation In this study we collected and analyzed DNA sequences of 98 genes from four wild relatives of A thaliana A halleri ssp gemmifera A halleri ssp halleri A lyrata ssp kamchatica and A lyrata ssp lyrata The ancestral states of these four species were compared to each other in terms of level of genetic variation However the ancestral species at the time of speciation were substantially more polymorphic than the extant geographical populations The observations are not fully compatible with speciation by strict allopatry At some species pairs parapatric speciation seems more reasonable in speciation of Arabidopsis The 98 gene sequences are also used for the congruence test between gene genealogy and species phylogeny Only 28 genes support the species phylogeny but there are 23 genes supports another major genealogy { lyrata} thaliana Based on the phylogenetic position change of A lyrata ssp kamchatica and Ks value for each species pair suggested the recent directional gene flow between A halleri ssp gemmifera and A lyrata ssp kamchatica

阿拉伯芥是第一个完成基因体定序的开花植物，其基因体资讯提供植物学研究的重要依据；在解析阿拉伯芥属物种的亲缘关系以及种化机制等重要的演化议题时，阿拉伯芥近缘的野生物种自然成了不可或缺的关键；跟阿拉伯芥近缘的物种包括A halleri及A lyrata，其中A halleri ssp gemmifera主要分布於中国东北、日本以及台湾，与近缘的A halleri ssp halleri其分布於欧洲隔著天山及大陆的障蔽，而A lyrata ssp kamchatica主要分布於东北亚及台湾，与分布於北美五大湖的A lyrata ssp lyrata被北极圈所分隔，这样的分布模式暗示异域种化的可能。藉由多基因分析比较祖先物种与现生物种遗传歧异度的相关可提供讯息探讨种化时期的族群遗传结构，本研究针对A halleri ssp gemmifera、A halleri ssp halleri及A lyrata ssp kamchatica、A lyrata ssp lyrata四个物种，两对互为亚种的姊妹群，以阿拉伯芥为外群进行研究，在四个物种完成98个同源基因的分子序列，利用套装软体MCMCcoal来估算祖先物种的遗传变异，亦估算现生物种的核苷酸歧异度，观察到？多物种配对中祖先物种遗传多型性大於现生物种DNA歧异度，显示异域种化模型并无法完全解释阿拉伯芥属物种的种化模式，在某些物种配对间邻域种化模式应比异域种化更为可能；在基因树与物种树的比较，98个基因片段的亲缘模式只有28个是与已知物种树一致的，有23个基因其树状图支持{ lyrata} thaliana的型式，藉由kamchatica位置的变化以及估算各物种配对间的平均同义置换率，推测在A halleri ssp gemmifera与A lyrata ssp kamchatica间具有近代的单方向基因交流。

The results show that all the hmgr genes from pigs, cattle and chickens are astable enzyme proteins with the same gene sequence characteristics and encoding protein and physical and chemical properties; all the amino acid sequences have a high degree of homology, containing two conservative HMG-CoA binding motifs and two NADPH binding motifs; all the amino acid sequences, containing signal peptide, are secreted proteins; they are all hydrophobic transmembrane proteins with five transmembrane domains; random coil and α-helix are the main structural elements in the HMGR polypeptide chain; all the predictions of three-dimensional structure are V- shaped; there are more closer evolution relationship between the HMGR gene from pigs and cattle.

结果表明：猪、牛和鸡HMGR基因序列特点及编码蛋白质理化性质基本相同，均属不稳定类酶蛋白；保守结构域氨基酸序列具有高度的同源性，均含有保守的2个β-羟基-β-甲基戊二酸单酰辅酶A结合基序和2个还原性烟酰胺腺嘌呤二核苷酸结合基序；均有信号肽，属分泌型蛋白质；属于跨膜的疏水性蛋白，均有5个跨膜结构域；无规则卷曲和α-螺旋是HMGR多肽链中的主要结构元件；三维结构预测都呈"V"字形；猪和牛HMGR基因的进化关系最近。

In chapter 6, we present a general model for construction of families of FH sequences based on pseudorandon sequences based on GF with two-level autocorrelation function.

第5章提出基于GMW序列构造跳频序列族的模型，证明该模型得到的跳频序列族具有最佳的汉明相关性能。

And furthermore basing on the marks of biostratigraphy and chronostratigraphy and relatively reliable isotopic age of the 14 3rd-order sequences associated with time-space match relation of biostratigraphy and sedimental system, the formed time limits of the 3rd-order sequences is calculated primarily as 1.5-3Ma, mainly appearing at 2Ma.

进而，结合生物地层及沉积体系的时空匹配关系等多方面的综合分析，对14次三级海平面升降事件的生物地层和年代地层的标识和参考已发表的同位素年龄数据，初步估算出三级层序的形成时限为1.5-3Ma，集中出现在2Ma。

In this paper, we propose a new visual cryptographic method for gray-level and chromatic images without pixel expansion. We simultaneously encrypt m successive pixels (called an "encryption sequence") each time in accordance with two basis matrices. In every m encryption sequences with b blacks, we make sure that b encryption sequences are encoded by black basis matrix, and the other ones are encoded by white basis matrix.

本研究提出一种不需要像素扩展的灰阶和彩色视觉密码的技术；我们的方法利用多点同时加密的概念，每次取连续的 m 个点做为加密序列进行加密，我们的方法可以确保在 m 个具有 b 个黑点的加密序列中，一定会有 b 个加密序列是使用黑点基础矩阵加密，另外的个则使用白点基础矩阵加密，因此在叠合影像上黑与白的变化很规律。

In the fourth chapter, firstly it introduces the Boolean functions algebraic expressions of the 2-value clock-controlled stop-and-go generator and Gunther generator. It reveals the balanced property of the two kinds of Boolean functions, and studies the Walsh cycle spectrum and the autocorrelation function. It also obtains the coincidence rate of their output sequences with affine sum of some bits of input sequences, and analyzes their ability of resisting the best affine approximation cryptanalysis and differential cryptanalysis. Secondly, we properly present a new definition of the Best Affine Approximation, namely BAA on the Boolean vector functions, followed by the spectral characteristic of such defined BAA attacks through using the decomposition formula of the union distribution for random variables. A lower bound of such BAA attacks is proposed. Finally, we also study the spectral characteristic of the second kind of nonlinearity of Boolean vector functions, followed by a higher bound of such nonlinearity. Furthermore, the limited relationship between the second kind of nonlinearity of Boolean vector functions and the linear structure of the linear combination of every component is analyzed.

在第四章中，首先给出了2值密钥流"停走生成器"和"衮特生成器"中实际存在的布尔函数的代数表示，揭示了这两类布尔函数的平衡性，随后研究了它们的Walsh循环谱和自相关函数等，得到了它们的输出序列与输入序列中的某些bit的仿射项的符合率，分析了它们抵抗最佳仿射逼近攻击和差分攻击的能力；其次，我们合理地给出了布尔向量函数最佳仿射逼近的新定义，利用布尔随机变量联合分布的分解式考察了相应的谱特征，并给出了布尔向量函数与其最佳仿射逼近的符合率的一个下界；最后，我们还考察了布尔向量函数第二类非线性度的谱特征，给出了布尔向量函数第二类非线性度的一个上界，并揭示了布尔向量函数第二类非线性度与其各个分量的线性和的线性结构之间存在的制约关系。

The partial LSU rDNA (28S rDNA) sequences of eighteen species of bryozoans and the complete 28S rDNA sequences of three representative species of bryozoan lineages were amplified and sequenced.

本文对常见的18种苔藓动物的LSU(28S)rRNA基因的部分序列以及苔藓动物部分类群代表种类的28S rDNA全序列进行了PCR扩增和序列测定。

In this thesis, we gives a novel graphical representation of DNA sequences by taking four special vectors in 2-D Cartesian coordinate system to represent the four nucleic acid bases in DNA sequences, so that a DNA sequence is denoted on a plane by a directed walk.

由于在DNA计算中，信息总是通过特定长度的DNA序列来表示的，因此，选择高质量的方式来表示DNA序列就成为一个重要的问题。

Chinese traditional virtue is humility and wariness,the compliment and praise to the others should be declination

中国人的传统美德是谦虚谨慎，对别人的恭维和夸奖应是推辞。如

We bought this house on the never-never.

我们以分期付款的方式买下这座房子。