典范主分量分析及其在山西植被与气候关系分析中的应用

排序是植被分析重要手段,大多数排序方法仅使用植数据。本文引入一个能够同时使用植被数据和环境数据的新方法－－典范主分量分析,它能够更好地描述植被与环境之间的关系。我们用该方法研究了山西植被与气候之间的关系,结果清楚地反映了山西植被与气候的地带分布规律及其相互关系,证明其是有效地植被环境关系分析方法。     

WINDOW FACTOR ANALYSIS:THEORETICAL DERIVATION AND APPLICATION TO FLOW INJECTION ANALYSIS DATA

Window factor analysis(WFA)is a self-modeling method for extracting the concentration profiles ofindividual components from evolutionary processes such as flow injection,chromatography,titrationsand reaction kinetics.The method takes advantage of the fact that each component lies in a specificregion along the evolutionary axis,called the‘window’.Theoretical equations are derived.The methodis used to extract the concentration profiles and spectra of seven bismuth species from data obtained byGemperline and Hamilton,who injected bismuth perchlorate into a flowing stream of hydrochloric acid.     

METHODOLOGY: DISCRIMINANT FUNCTION ANALYSIS OF COMPOSITIONAL DATA: AN EXAMPLE FROM HYDRAULIC GEOMETRY

Many of the data sets analyzed by physical geographers are compositional in nature: they have row vectors that add to one (or 100%). These unit-sum constrained data sets should not be analyzed by standard multivariate statistical methods. Significant differences were found in the log-ratio mean vectors of the hydraulic exponents (which are unit-sum constrained) for two classes of streams: those with cohesive, non-vertical banks, and those with one firm and one loose bank. Compositional discriminant function analysis of bank stability on the basis of hydraulic geometry had a success rate of 88%, making routinely archived measurements of stream width, cross-sectional area, mean velocity, and discharge a readily available data base for predicting the stability of stream reaches. [Key words: geomorphology, hydraulic geometry, discriminant function, statistics.]     

因子分析法在水源保护区水质评价中的应用

通过对松华坝水源保护区2001-2007年的两个监测断面水质进行因子分析,两个断面8项水质指标中TN均超标,其余水质指标均未超标。使用SPSS13．0工具进行分析,结果显示,两个监测断面的主要污染因子各异,牧羊河断面的主要污染物为TN和TP,而冷水河断面的主要污染物为CODMn、BOD5和TP。松华坝水源保护区水质保护形势十分严峻。必须高度重视,采取切实措施,处理好水源区保护和发展的关系,保护好松华坝水源保护区水质,确保昆明市民饮水安全。     

云南省滇中地区工业结构模糊聚类分析

运用模糊聚类分析法对云南省滇中7个市、地区的工业结构进行模糊聚类分析。结果滇中分为4类地区，第一类地区为昆明市；第二类地区为曲靖市、红河州；第三类地区为玉溪市、楚雄州和大理市；第四类地区为丽江市。分析结果与云南省滇中地区工业产业结构的实际情况比较吻合。     

WEIGHTED ANALYSIS OF PRINCIPAL COMPONENTS: TWO APPROXIMATIONS TO STATISTICAL WEIGHTS

Two approximate methods for weighted principal components analysis (WPCA) were devised and testedin numerical experiments using either empirical variances (obtained from replicated data) or assumedvariances (derived from unreplicated data). In the first ('spherical') approximation each data vector wasassigned a weight proportional to the geometrical mean of its variances in all dimensions. Thearithmetical mean of variances was used instead in the other approximation. Both the numericalexperiments with artificial data containing random errors of various kinds (constant, proportional,constant plus proportional, Poisson) and the analysis of two sets of Raman spectra clearly indicated thenecessity of introducing statistical weights. The spherical approximation was found to be slightly betterthan the arithmetical one. The application of statistical weighting was found to improve the performanceof PCA in estimation problems.     

极地冰雪化学组成分析:毛细管离子分析与离子色谱的比较

与传统的离子色谱相比较，讨论了目前分析化学的前沿技术毛细管离子分析技术，它具有分析快速、高效、分离度好、样品预处理简单、用样量少、维护方便、自动化程度高等特点，完全可替代目前在分析极地冰雪中所通用的离子色谱仪，成为极地冰雪化学分析强有力的新的分析工具     

主成分分析方法在区域经济研究中的应用--以新疆为例

主成分分析方法（PCA）及采用此法做综合评价的原理和步骤，并用两个方面的实例具体阐述了主成分分析方法在区域经济研究中的应用，最后对这种方法的特点及应用中须注意的问题进行了初步总结。     

主成分分析在城市PRED系统可持续发展研究中的应用——以广东省所辖21个城市为例

依据1995-1999年广东省所辖21个城市科技人口数量增长率，城市人口数量增长率，耕地面积递减率，森林覆盖递减率，三废处理能力增长率，三废排放增长率，人平工资增长率，人均GDP增长率等指标统计资料，应用主成分分析法分析了广东城市人口，资源，环境和经济发展（PRED）系统的可持续发展过程，并从众多PRED系统因子中揭示出典型的敏感因子（主成分），同时，也为城市PRED）系统的可持续发展过程。并从众多PRED系统因子中揭示出典型的敏感因子（主成分）。同时，也为城市PRED系统可持续发展进程的分类提供新的依据。     

SHORT COMMUNICATION DYNAMIC HEADSPACE ANALYSIS:OPTIMIZATION OF TITRATION BY EXPERIMENTAL DESIGN

The dynamic headspace titration of the volatile constituents of the black truffle(Tuber Melanosporum)isplanned to be carried out with the new gas chromatographic device DCI using Tenax trapping.In thispaper the necessary optimization of the experimental factors which influence the desorption of thevolatiles from the sample and the adsorption on the trap is carried out by experimental design.The studyof the isoresponse curves makes it possible to determine the optimum conditions for a rapid titration ofhighest sensitivity and reproducibility,avoiding water trapping.