41 resultados para multivariate Datenanalyse

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Rhesus macaques and stump-tailed macaques are sympatric in western Yunnan (China), coexisting or occupying habitats that show little difference. This paper tests hypotheses based on theoretical expectation from the differing biomechanical demands of terrestrial and arboreal quadrupedalism in stump-tailed macaques and rhesus macaques, respectively. Individuals of these two macaque taxa were markedly separated by the first two principal components and discriminant analyses based on 18 variables of the upper limb. The rhesus macaques appear to be more adapted for arboreal quadruped habits because of elongation of the clavicle and forearm, a larger humeral head and greater midshaft sagittal diameters of the radius and ulna.

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The optimization of the organic modifier concentration in micellar electrokinetic capillary chromatography (MECC) has been achieved by a uniform design and iterative optimization method, which has been developed for the optimization of composition of the mobile phase in high performance liquid chromatography. According to the proposed method, the uniform design technique has been applied to design the starting experiments, which can reduce the number of experiments compared with traditional simultaneous methods, such as the orthano design. The hierarchical chromatographic response function has been modified to evaluate the separation quality of a chromatogram in MECC. An iterative procedure has been adopted to search the optimal concentration of organic modifiers for improving the accuracy of retention predicted and the quality of the chromatogram. Validity of the optimization method has been proved by the separation of 31 aromatic compounds in MECC. (C) 2000 John Wiley & Sons, Inc.

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Multivariate classification methods were used to evaluate data on the concentrations of eight metals in human senile lenses measured by atomic absorption spectrometry. Principal components analysis and hierarchical clustering separated senile cataract lenses, nuclei from cataract lenses, and normal lenses into three classes on the basis of the eight elements. Stepwise discriminant analysis was applied to give discriminant functions with five selected variables. Results provided by the linear learning machine method were also satisfactory; the k-nearest neighbour method was less useful.

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新生代以来,全球气候经历了一系列的冷暖交替,呈现总体变冷的趋势。对该时期不同区域气候变化过程的深入研究有助于我们更好地理解现今全球气候变化规律。中新世是新生代古气候与古环境演变的一个重要转折时期,定量重建山东山旺中新世气候是认识和理解中国东部与东亚新近纪气候演变的一个关键环节。 将化石植物作为气候代用指标,用于研究过去全球气候变化,已经广为国际科学界接纳。国际上,定量研究第三纪气候的植物学方法按照不同原理可以划分为两大类,其各自代表分别为基于化石的现存最近亲缘类群生态适应度推演古气候参数值的共存分析法(Coexistence Approch, CA )和基于叶片形态特征与气候相关关系的叶缘分析(Leaf Margin Analysis, LMA )与气候叶片多变量程序(Climate Leaf Analysis Multivariate Program, CLAMP)。两大主流方法各有优势,也各有局限性。前人运用两大主流方法对山旺中新世植物群相同地层,同套数据的分析结果表明:LMA 和CLAMP 所估测年均温数值要显著低于CA 所估测的数值。其差异的原因既可能是LMA 和CLAMP 由于埋藏因素的影响造成估测值偏低,也可能由于CA 数据库数据主要来自于欧洲和北美而缺乏东亚的资料所致。 本论文提出了一种新的方法——分布区叠加分析(Overlapping Distribution Analysis, ODA )对山旺中新世古气候进行定量重建。ODA 采用最近亲缘类群在叠加区间的气候参数来重建化石植物所生活的当时当地的气候。其详细步骤如下:1. 鉴定化石植物和认定它们的最近亲缘类群(尽量到种级水平)。2. 调查这些最近亲缘类群的分布数据(包括经度、纬度和海拔数据)。某些类群可能会有不止一个最近亲缘类群,须将这些最近亲缘类群的分布数据合并。3. 对分布数据分析,得出包含最多类群的最大叠加区间。4. 调查在最大叠加区间中气象站点的气候数据。5. 按照公式(1)和(2)来转换年均温数据TU=T0 - (HU -H0)×Γ (1); TL=T0 - (HL -H0)×Γ (2) 其中HU (m) 是海拔叠加区间的上界; HL (m) 是海拔叠加区间的下界; H0 (m) 气象站的实测海拔; T0 (ºC) 气象站的实测年均温; TU (ºC) 在海拔叠加区间气温的下界; TL (ºC) 在海拔叠加区间气温的上界; 系数Γ 为大气垂直直减率,年均温为0.5ºC/100m,最冷月均温为 0.45ºC/100m,最热月均温为 0.6ºC/100m。同样的方法,在海拔叠加范围内最冷月均温与最热月均温范围也可以确定,而降水量则采用气象台站的原始数据。6. 在这些转换数据的基础上,得出年均温,最冷月均温,最热月均温,年较差和年平均降水量波动范围。 ODA 分析结果表明:山旺中新世时期年均温为10.9-14.5oC,年较差为21.1-22.7oC,最冷月均温为-0.5-3.3oC,最热月均温为21.9-25.0oC,年平均降水量为1107.3-1880.0mm 。同时本论文还定量恢复了山旺硅藻土矿各层的古气候参数,其所估测的古气候参数数值与CLAMP 和LMA 的结果一致,而与CA 不同。对山旺气候参数的恢复表明,虽然其中新世年均温与现在相似,但最冷月均温要高于现在。 本项研究的创新之处是选择同一个研究地点(山东山旺),依据同一套数据(化石植物的类群资料),采用国际上以不同原理为基础的主流方法,同时加入我们自己提出的新方法,进行的古气候重建,对所获得气候参数值进行对比和验证,并对其存在的差异进行分析和探讨。

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Based on the pelage characteristics and results of multivariate and univariate analyses, a new subspecies is described in this study, and a taxonomic revision of Tamiops swinhoei from China is presented. In total, 123 specimens of Tamiops swinhoei were in

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Geographic variation of Chevrier's field mouse (Apodemus chevrieri) (Milne-Edwards, 1868) (Muridae: Murinae) from southwestern China based on cranial morphometric variables. Zoological Studies 47(4): 393-401. A sample of 134 specimens of Apodemus chevrieri was investigated in the present study. Individuals were divided into male and female groups, and these were respectively subjected to multivariate analysis. Results indicated that 3 geographic populations of A. chevrieri inhabit southwestern China: a Sichuan population in western Sichuan Province; a northwestern Yunnan population ranging from northwestern Yunnan Province eastward to southern Sichuan Province; and a central Yunnan population in central Yunnan Province. In addition, a coefficient of difference analysis was performed among these 3 geographic populations. The results suggested that these 3 geographical populations of A. chevrieri belonged to 2 subspecies. Furthermore, we discuss the relationships of the subspecific differentiation of A. chevneri with changes in latitude in southwestern China.

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运用多变量形态度量学和框架结构形态学的方法,测量了采自滇池流域6个不同地点的149尾滇池金线鲃(Sinocyclocheilus grahami)的标本.应用多变量形态度量学分析,选择了20个框架结构性状和19个常规性状,进行主成成分分析.主成成分分析结果的散布图显示,6个不同地点的标本聚在一起没有分开,表明滇池金线鲃的各居群之间在可数性状和可量性状上均未表现出明显的差异,说明滇池金线鲃在形态上还未发生明显的种下分化.

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A sample of 114 specimens of Dremomys pernyi was investigated, 73 of which had intact skulls and were subjected to multivariate, coefficient of difference (C. D.), and cluster analyses. Results indicate that 4 subspecies (groups) of Dremomys pernyi inhabi

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In this paper, we report the findings of a comparative study of the elbow joints of five species of macaque that inhabit China: Macaca assamensis, M. arctoides, M. mulatta, M. thibetana and M. nemestrina. Results of multivariate analyses of size-related variables and indices of the elbow joint suggested that the breadths of the ventral aspect of the trochlea and of the medial epicondyle of the humerus as well as indices describing the head of the radius are important factors for discriminating these species. The elbow joint of M. arctoides was most similar to that of M. thibetana, no doubt reflecting recency of common ancestry and similarity in terrestrial locomotion. The structures of the elbow joints in M. nemestrina and assamensis seemed more adapted to arboreal quadrupedalism. The elbow joint of M. mulatta, however, appears intermediate between the most terrestrial and the most arboreal forms.