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1.
This is a first foray into the historical start and early years of chemometrics from about 1972 onwards.We have gathered interviews with three originators(Kowalski,Wold and Massart)as well as with aselected group of six other well-known chemometricians who gradually became active in the 1970s(Christie,Clementi,Hopke,Martens,Brown and Deming).The interviews include amongst a host ofsubjective recollections a succinct record of the key historical literature as highlighted by the interviewees'own rankings of‘earliest’and‘best’.A discussion of the most general commonalities in these interviews together with other historicalmaterial is presented in the second part of the paper. 相似文献
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Statistical methods should be a means of reasoning and decision making integrated into research designin analytical chemistry and not merely an instrument for analysing empirical data.Consequently,full andrigorous use of these methods should be encouraged from the earliest stages of postgraduate training.In this paper a selection of well tried,straightforward procedures is given in the form of practicalstudies that give reliable,consistent and meaningful results. 相似文献
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The application of several chemometric topics in connection with an environmental study is described.Atwo-way ANOVA is used to show the irregularity of the distribution of heavy metals in the rural soilsaround a lead smelter.Multivariate statistical methods are also applied to show significant correlationsbetween metals and the wind direction.Principal components analysis and Varimax rotation seem toconfirm the validity of the conclusions. 相似文献
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STANLEY N.DEMING JOHN A.PALASOTA JOSEPHINE M.PALASOTA Department of Chemistry University of Houston Calhoun Ro Houston TX - U.S.A. 《地理学报(英文版)》1991,(3)
Chemometrics is defined as the application of mathematical and statistical methods to chemical systems.Systems theory is seen to be useful for organizing and categorizing the inputs to and outputs fromchemical systems.Advances in measurement science in the 1950s and 1960s,particularly in analyticalchemistry,created a need for a multivariate approach to data analysis.Early chemometrics emphasizedthe use of structure-finding methods for existing data sets.In many instances,data sets can be obtainedfrom designed experiments.Such data sets are more likely to contain the desired information and the datacan usually be acquired at less cost.Renewed interest in statistical process control will provide many new,more robust data sets in the future. 相似文献
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Cross-validatory estimation of the bilinear model based on principal components is reviewed andKrzanowski's modification of Wold's procedure is described. Two different types of residuals useful forchecking model adequacy are defined and indices measuring the influence of each observed unit on theestimates of the parameters are discussed. A method for the selection of variables derived from Procrustesanalysis is described. Results arising from the study of two sets of enological data are given. 相似文献
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W.G.DE RUIG J.M.WESEMAN State Institute for Quality Control of Agricultural Products 《地理学报(英文版)》1990,(1)
In the series of analytical techniques for identification of chemical substances,infrared spectrometrypresents by far the highest information content.However,the information is most complicated too.Itconcerns a multitude of band positions,band intensities and band shapes,which,moreover,can bedisturbed by matrix and other effects.The high redundancy,however,allows conclusions to be made bya qualitative,subjective procedure.IR is often used to prove the equality between a sample and a reference material,e.g.in quality controlof a production process.In forensic control,the question to be answered is mostly not to prove equality,but whether or not the presence of a compound in a sample,e.g.a drug,can be proved.Moreover,testinghas to be performed according to objective rules.To fulfil these requirements,a new retrieval algorithm,the‘Adequate Peaks Search’,is presented.Itconcerns representing the reference spectra by sets of adequate peak positions and the sample spectrumby a set of all peak positions,whereafter the cross-sections of the sample set and the reference sets aredetermined.The concept‘adequate peak’is defined and criteria have been formulated to evaluate theresults into a positive(presence of the analyte is proved) or negative(presence is not proved)conclusion.The detection limit when the Adequate Peaks Search(APS)method was applied was four to seven timeslower than that attained by a number of experts. 相似文献
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LEMING SHI ZHILIANG LI ZHIHONG XU ZHONGXIAO PAN LESHAN WANG Laboratory of Computer Chemistry Institute of Chemical Metallurgy Chinese Academy of Sciences Beijing P.R.China 《地理学报(英文版)》1991,(3)
This paper describes the simultaneous determination of cobalt,nickel,copper,zinc and cadmium byspectrophotometry and the Kalman filter method.Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ)and Cd(Ⅱ)react with 5-bromo-2-(2-pyridylazo)-5-diethylaminophenol(5-Br-PADAP)in the presence of cationic surfactant cetylpyridinium bromide(CPB)to form five different coloured ternary complexes.The absorption curves ofthese complexes overlap severely in the scanning range 500-620 nm.The Kalman filter algorithm issuccessfully applied to resolve the overlapped absorption curves and therefore makes the simultaneousdetermination of these metallic ions possible without tedious pretreatment.The proposed method isapplied to analyse the titled elements in synthetic samples and in environmental samples such as hair,fingernail and river water samples with satisfactory results. 相似文献
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V.S.ROSE R.M.HYDE Department of Physical Sciences Wellcome Research Laboratories South Eden Park Ro Beckenham Kent BR BS U.K.H.J.H.MACFIE AFRC Institute of Food Research Reading Laboratory Shinfiel Reading RG AT U.K. 《地理学报(英文版)》1990,(5)
A survey of members of the U.K.QSAR Discussion Group has been made to determine the extent ofuse and development of chemometric and artificial intelligence(AI)methods in the analysis ofmultivariate quantitative structure-activity relationship(QSAR)data in the U.K.Chemometric methodswere found to be well established in both industrial and educational establishments and there wassignificant method development occurring.AI methods were not employed to any great extent and thegeneral level of interest in these techniques was low compared to chemometric methods.A requirementfor more education in multivariate statistical methods and regression methods was indicated.A need fora user-friendly,comprehensive,commercially available multivariate statistical package containingmultivariate stability testing and regression diagnostic methods was identified. 相似文献
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我国工业布局的变化趋势 总被引：7，自引：2，他引：5
解放以来,我国工业布局发生了重大的变化,积累了丰富的资料和经验。系统地分析、评价我国工业布局变化的规律和趋势是经济建设中的重大实践问题,也是经济地理学 相似文献
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植物区系地理研究中的重要参数——相似性系数* 总被引：45，自引：2，他引：43
相似性系数的正确理解和运用,对植物区系地理学中的植物区系分区、过渡区的植物区系地理属性及植物区系起源演化都具有重要的理论意义。文中通过相似性系数、种相似性系数、属相似性系数和科相似性系数等术语的阐述,提出了"区系相似性系数(Coeficient of simi-larity of flora)"概念。简要介绍了属或种(或科)相似性系数在应用中存在的问题和解决的办法。并建议在植物区系地理比较研究中采取统一、科学的计算公式。 相似文献
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论沙粒两种起动关系与沙粒跃移的双重性 总被引：2，自引：8，他引：2
研究沙粒两种起动关系是深入认识沙粒两种起动效能的继续和发展。文章分析了沙粒两种起动的不同性质，首次把流体起动界定为风蚀性起动，把跃移质冲击起动界定为置换性起动。认为流体起动具有主动分异性，而冲击起动只有随机分异性。根据这些特性对沙粒两种起动效能和沙粒连续移动提出了新义。认为沙粒跃移具有双重性，跃移质有其冲击地表的一面，也有其大量耗能的一面。沙粒两种起动具有兴衰与共的不可分割关系。地表风蚀是沙粒两种起动优势互补相互促进的结果；而地表堆积有时是跃移质耗能过多引起两种起动互相制约的结果。通过多方论证，将沙粒两种起动效能之由传统的19：1，初步改为4：1乃至3：1。 相似文献
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《Urban geography》2013,34(1):84-95
This paper suggests a GIS-based methodology for the investigation of the extent to which the inhabitants of a representative sample of city residents perceives itself as living in socially constituted neighborhood territories. We ask residents about the relevancy of the neighborhood as a social unit and to delineate their neighborhood boundaries. We then define these delineations as polygons in GIS, measuring the tendency of neighbors to define merging territorial bases for their neighborhoods. Three possible patterns are identified: (1) lack of perceived boundaries resulting from the irrelevancy of the neighborhood, (2) personal senses of localities that do not merge into communal territories by immediate neighbors—in this case we conclude that residents experience some sense of locality but they do not share any common sense of neighborhood—and (3) the tendency of residents' delineations to merge with those of their neighbors demonstrating, by thus, the social constitution of communal sense of neighborhood. We conclude that in most of the city the neighborhood is marginally relevant with only several areas, located in the outer ring of the city, presenting a coherent territorial sense of neighborhood. 相似文献
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介绍了根据自己研究测定的Ｌｉ，Ｋ／Ｃｌ，ＳＯ４－Ｈ２Ｏ体系２５℃的渗透系数等热力学性质获得的Ｐｉｔｚｅｒ混合参数，并用自由能最小化方法计算了２５℃ Ｌｉ，Ｋ／Ｃｌ．ＳＯ４－Ｈ２Ｏ体系的相图。结合测定得到的该体系５０℃、７５℃的相图和复盐ＬｉＫＳＯ４转变温度的研究，整个体系相平衡和热力学的研究结果可用于盐湖卤水中锂盐的分离提取。 相似文献
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文章把世界经济区域集团化看作为资本主义以来的一种经济区域现象，从经济行为主体对地理空间的无限追求出发，分析不同历史阶段上这种区域现象发展的不同表现及其与国际政治经济形势、世界经济的空间结构和国家间地理基础的一致性等因素的关系，力求找出发展规律，以此指导对当前各种区域集团化现象的认识。 相似文献
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世界遗产地旅游产品开发的创新思考 总被引：2，自引：1，他引：1
麻新华 《云南地理环境研究》2008,20(4):103-106
遗产旅游已经成为人们最火爆的旅游产品。然而,世界遗产地旅游产品开发值得我们深思。对世界遗产地旅游产品开发的要求、世界遗产地旅游产品应该具有的特征、世界遗产地适宜开发的旅游产品类型、旅游产品开发模式等方面进行了重新思考,利于世界遗产的保护。 相似文献
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地貌发育阶段的定量研究 总被引：7，自引：0，他引：7
文章提出用临界侵蚀积分值作为划分流域发育阶段的定量指标,是对经典理论的发展,主要表现在:1)将地貌发育阶段纳入开放系统的概念之中;2)避免高程积分法在划分发育阶段上的不确定性;3)建立地貌发育阶段与流域物质迁移之间的定量关系;4)区分自然侵蚀和加速侵蚀。用文中的临界侵蚀方程对黄土高原丘陵沟壑区分析计算,得到临界侵蚀积分值为0.30和0.70,即当侵蚀积分值小于0.30寸,流域处于侵蚀早期;当侵蚀积分值大于0.30,小于0.70时,流域处于侵蚀中期;当侵蚀积分值大于0.70时,流域处于侵蚀晚期。对于纯自然侵蚀过程,与临界侵蚀积分值相对应的年代及侵蚀模数为7万年前,7008t/km~2·a和距今7.2万年以后,7008t/km~2·a。目前黄土高原丘陵沟壑区加速侵蚀所占比例为30％。 相似文献