Journal of research of the National Bureau of Standards最新文献_第5页

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.035

K. Schostack, P. Parekh, S. Patel, E. R. Malinowski

{"title":"Evolutionary Factor Analysis","authors":"K. Schostack, P. Parekh, S. Patel, E. R. Malinowski","doi":"10.6028/jres.093.035","DOIUrl":"https://doi.org/10.6028/jres.093.035","url":null,"abstract":"Because of chemical interconversion, many chemical systems cannot be physically separated, making chemical identification and quantification difficult. The spectra (IR, UV, Visible, Raman, CD, etc.) of such systems exhibit overlapping contributions of uncataloged components, confounding the identification as well as the quantification. Strategies based on factor analysis [1], a chemometric technique for handling complex multi-dimensional problems, are ideally suited to such problems. Abstract factor analysis (AFA) reveals the number of spectroscopically visible components. Evolutionary factor analysis (EFA) [2-4] takes advantage of experimental variables that control the evolution of components, revealing not only the concentration profiles of the components but also their spectra even when there are no unique concentrations or spectral regions. Evolutionary factor analysis makes use of the fact that each species has a single, unique maximum in its evolutionary concentration distribution curve. We have recently applied this self-modeling method to the infrared spectra of stearyl alcohol in carbon tetrachloride solution. The evolutionary process of this system was achieved by increasing the concentration of stearyl alcohol from 0.0090 to 0.0800 g/L in 15 stages, each time recording the IR spectra from 3206 to 3826 cm '. The spectra were corrected for baseline shift, solvent absorption and reflectance losses. The 15 spectra were then digitized every 3 cm ' and assembled into a 35 x 15 absorbance matrix [A] appropriate for factor analysis. The factor indicator function [1], the reduced eigenvalue [5] and cross validation [6] indicated that three species contribute to the observed spectra. Thus AFA expresses the data matrix as a product of a 35 x 3 absorptivity matrix [E],,,, and 3 X 15 abstract concentration matrix [C],h,,.","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"256 - 257"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71361963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Chemometrics in Europe: Selected Results 欧洲的化学计量学:选定结果

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.036

W. Wegscheider

引用次数: 0

Effects of Ionizing Radiation on Nutrients in Foods 电离辐射对食物中营养素的影响

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.078

D. Thayer, J. B. Fox, R. Jenkins, S. Ackerman, J. Phillips

引用次数: 2

Accuracy in Microanalysis by Electron Energy-Loss Spectroscopy 电子能量损失谱在微量分析中的准确性

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.082

R. Egerton

{"title":"Accuracy in Microanalysis by Electron Energy-Loss Spectroscopy","authors":"R. Egerton","doi":"10.6028/jres.093.082","DOIUrl":"https://doi.org/10.6028/jres.093.082","url":null,"abstract":"[I] Williams, D. B., Practical Analytical Electron Microscopy in Materials Science, Philips Electron Optics Publishing Group, Mahwah, NJ (1984). [2] Joy, D. c., Romig, A. D., and Goldstein, 1. I., Principles of Analytical Electron Microscopy, Plenum Press, New York (1986). [3] Goldstein, J. I., Newbury, D. E., Echlin, P., Joy, D. C., Fiori, C. E., and Lifshin, E., Scanning Electron Microscopy and X-ray Microanalysis, Plenum Press, New York (1981) p. 435. [4] Liebhafshy, H. A., Pfeiffer, H. G., and Zemany, P. D., X-ray Microscopy and X-ray Microanalysis, Elsevier/ North Holland, Amsterdam (1960) p. 321. [5] Cliff, G., and Lorimer, G. W., J. Microsc. (U.K.) 103, 203 (1975). [6] Michael, J. R., M.S. Thesis, Lehigh University (1981) p.41. [7] Romig, A. D., and Goldstein, J. I., Detectability Limits and Spatial Resolution in STEM X-ray Analysis: Application to Fe-Ni Alloys, Microbeam Analysis1979, San Francisco Press (1979) p. 124. [8] Lyman, C. E., Microanalysis Limits on the Use of Energy Dispersive X-ray Spectroscopy in the Analytical Electron Microscope, Microbeam Analysis-1986, San Francisco Press (1986) p. 434. [9] Lyman, C. E., and Michael, J. R., A Sensitivity Test for Energy Dispersive X-ray Spectrometry in the Analytical Electron Microscope, Analytical Electron Microscopy1987, San Francisco Press (1987) in press. rIO] Williams, D. B., Towards the Limits of Microanalysis in the Analytical Electron Microscope, Electron Microscopy and Analysis-1987, The Institute of Physics (1987) in press. [II] Ziebold, T. 0., Anal. Chern. 36, 322 (1967). [121 Williams, D. B., Standardized Definitions of X-ray Analysis Performance Criteria in the AEM, Microbeam Analysis-1986, San Francisco Press (1986) p. 443. [13] Williams, D. B., and Steel, E. B., A Standard Cr Thin Film Specimen to Measure the X-ray Peak to Background Ratio (Using the Fiori Definition) in Analytical Electron Microscopes, Analytical Electron Microscopy-1987, San Francisco Press (1987) in press. [14] Fiori, C. E., Swyt, C. R., arid Ellis, J. R., The Theoretical Characteristic to Continuum Ratio in Energy Dispersive Analysis in the Analytical Electron Microscope, Microbeam Analysis-1982, San Francisco Press (1982) p. 57. [IS] Vale, S. H., and Statham, P. J., STEM Image Stabilization for High Resolution Microanalysis, Proc. XIth Int. Congo on Electron Microscopy, Kyoto 1986, Japanese Society of Electron Microscopy, Tokyo (1986) p. 573.","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"372 - 374"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

An Instrument for Determination of Energy Oxygen and BOD5 能量、氧和BOD5的测定仪器

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.057

L. Ciaccio, K. Hameyer

{"title":"An Instrument for Determination of Energy Oxygen and BOD5","authors":"L. Ciaccio, K. Hameyer","doi":"10.6028/jres.093.057","DOIUrl":"https://doi.org/10.6028/jres.093.057","url":null,"abstract":"\"The biochemical oxygen demand (BOD) determination is an empirical test in which standardized laboratory procedures are used to determine the relative oxygen requirement of waste waters, effluents and polluted waters [1].\" This method has several well-known drawbacks, i.e., 5-day duration of the test, lack of correspondence of the BOD bottle to the biological system of the receiving water body, and the nonquantitative nature of the BOD test [2]. Each of these factors seriously compromises the present testing procedure. The length of the analysis time, which is generally 5 days, makes the test practically useless [2,3] in real-time control of pollution, and the prescribed condition of carrying out the test at a constant temperature of 20 'C is an inconvenience. The objective of this investigation was to develop an instrument which would measure biological oxygen demand by some parameter which was meaningfully related to the oxygen depleting activity of waste waters, precise, and of short measurement duration (I hour or less). The variable chosen was energy oxygen, a thermodynamic value related to the substrate free energy of oxidation in cell synthesis [2-8]. Two factors, energy oxygen and endogenous oxygen, comprise ultimate biochemical oxygen demand [2,3,4]. Five-day BOD (BOD5 ), may not necessarily exert the ultimate biochemical oxygen demand because 5 days may be too short a time for complete stabilization by the bacteria. Thus we can summarize","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"311 - 312"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Chemiluminescence Detection in Flowing Streams—Immobilized and Solid-State Reagents 流动中的化学发光检测-固定化试剂和固态试剂

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.135

T. Nieman

引用次数: 5

Quantitative Secondary Ion Mass Spectrometry 定量二次离子质谱法

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.140

M. Grasserbauer

{"title":"Quantitative Secondary Ion Mass Spectrometry","authors":"M. Grasserbauer","doi":"10.6028/jres.093.140","DOIUrl":"https://doi.org/10.6028/jres.093.140","url":null,"abstract":"mental standards, and by statistical and systematic errors in the measurement of x-ray lines and in the separation of line intensity from spectral background. The errors in estimating the characteristics of the detector system, with exception of deadtime effects, cancel when the emission from the specimen is divided by that from the standard. The estimate of achievable accuracy of EPMA and the comparison of diverse approaches must therefore involve consideration of theoretical aspects, of errors in the values of parameters used in the procedure, and of operational errors in specimen and standard preparation and in analysis. In the development of current \"correction procedures,\" theoretical, mathematical and measurements aspects are interwoven. For instance, the distribution in depth of x-ray generation can either be calculated by Monte Carlo calculations, which are limited by the accuracy of available parameters, or by exeriments with sandwich tracer targets. To further complicate things, some Monte Carlo calculations use techniques empirically adjusted to fit the available experimental evidence. Since the precision of measurement of relative x-ray intensities is better than the accuracy of results on specimens of known composition, there is room for improvement; but, to achieve this, the diverse potential source of errors will have to be unraveled and tested separately.","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"510 - 518"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

High Resolution Nonlinear Laser Spectroscopy 高分辨率非线性激光光谱学

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.110

J. C. Wright

{"title":"High Resolution Nonlinear Laser Spectroscopy","authors":"J. C. Wright","doi":"10.6028/jres.093.110","DOIUrl":"https://doi.org/10.6028/jres.093.110","url":null,"abstract":"High resolution laser techniques were developed that address the problems listed above. The techniques are collectively called site selective laser spectroscopy. They relied upon the idea that a narrow band laser could be tuned to excite selectively an absorption line of a specific component or site within a sample so the resulting fluorescence spectrum came only from the site or component excited. One could simplify spectral congestion with this approach. One could also eliminate broadening that was caused by inhomogeneities in the samples because excitation within a broadened line would only excite components that had energy states resonant with the laser so the resulting fluorescence spectrum would not reflect the inhomogeneities. These methods were applied to matrix isolation, low temperature organic glasses, Shpol'skii systems, inorganic analysis using precipitates, and supersonic jet spectroscopy to measure a variety of inorganic and organic materials at ultra-trace levels. The methods all relied upon sample fluorescence and they failed if the samples were non-fluorescent. We have recently shown that there is a new family of high resolution laser spectroscopies that have the same capabilities but do not require a fluorescent sample. These spectroscopies are based upon nonlinear mixing where several tunable lasers are focused into a material and new frequencies are formed at all of the sums and differences of the original laser frequencies. This nonlinear mixing is resonantly enhanced when some of the laser combinations match resonances of components in the sample. The nonlinear mixing can be used to perform atomic spectroscopy and molecular spectroscopy. We will concentrate on molecular spectroscopy in this discussion. One can perform component selection by tuning the lasers to match resonances on one specific component in the sample. One would then expect to have that component contribute dominantly to the nonlinear mixing. One can also eliminate inhomogeneous broadening by tuming the lasers to match the resonances of specific sites within the inhomogeneously broadened line. Again, one would expect that those sites would contribute dominantly to the mixing and the nonresonant sites would be discriminated against. We have tested these ideas in several model systems using four wave mixing spectroscopy. The two model systems are pentacene doped into p-terphenyl crystals and pentacene doped into benzoic acid crystals where p-terphenyl was added in small amounts to introduce controlled amounts of inhomogeneous broadening. The experiments were done at 2 K to eliminate thermal effects. There are four schemes that one can use to establish resonances with the pentacene molecules. In all of them, one establishes resonances with the vibrational levels, the excited electronic states, and the vibrational levels of the excited electronic state (which we will call vibronic states). The four schemes differ in which states are involved in the resonance ass","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"440 - 441"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71362936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 26

Sodium Taurocholate Micelles in Fluorometrix Analysis 牛磺胆酸钠胶束荧光分析

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.112

L. McGown, K. Nithipatikom

引用次数: 3

Increased Accuracy in the Automated Interpretation of Large EPMA Data Sets by the Use of an Expert System 通过使用专家系统提高了大型EPMA数据集自动解释的准确性

Journal of research of the National Bureau of Standards Pub Date : 1988-05-01 DOI: 10.6028/jres.093.037

K. Janssens, W. Van Borm, P. Van Espen

{"title":"Increased Accuracy in the Automated Interpretation of Large EPMA Data Sets by the Use of an Expert System","authors":"K. Janssens, W. Van Borm, P. Van Espen","doi":"10.6028/jres.093.037","DOIUrl":"https://doi.org/10.6028/jres.093.037","url":null,"abstract":"I INPUT, NEXT EXPERIMENTAL k\"-WALUES [13] Lohninger, H., and Varmuza, K., Anal. Chem. 59, 236 (1987). [14] Wold, S., Wold, H., Dunn, W. J., 111, and Rube, A., Umea University, Report UMINF-83.80, 1982. [15] Martens, H., Multivariate Calibration: Combining Harmonies from an Orchestra of Instruments into Reliable Predictions of Chemical Composition, 46th Session of the Intern. Statistical Institute, Tokyo (1987). [16] Hellberg, S., A Multivariate Approach to QSAR, Research Group for Chemometrics, Umea University (1986). [171 Wold, S., Sjoestroem, M., Carlson, R., Lundstedt, T., Hellberg, S., Skagerberg, B., Wikstroem, C., and Oehman. J., Anal. Chim. Acta 191, 17 (1986). [181 Bandemer, H., and Otto, M., Mikrochim. Acta 1986 11, 93. [191 Blaffert, T., Anal. Chim. Acta 161, 135 (1984). [20] Otto, M., and Bandemer, H., Anal. Chim. Acta 184, 21 (1986). [21] Otto, M., and Bandemer, H., Chemom. Intell. Lab. Syst. 1, 71 (1986). [22] Kateman, G., J. Res. Natl. Bur. Stand. (U.S.) 93, 217 (1988). [23] Schostack, K., Parekh, P., Patel, S., and Malinowski, E. R., J. Res. Nati. Bur. Stand. (U.S.) 93, 256 (1988). [24] Janssens, K., Van Borm, W., and Van Espen, P., J. Res. Natl. Bur. Stand. (U.S.) 93, 260 (1988). [25] Derde, M. P., and Massart, D. L., Anal. Chim Acta 191, 1 (1986).","PeriodicalId":17082,"journal":{"name":"Journal of research of the National Bureau of Standards","volume":"93 1","pages":"260 - 264"},"PeriodicalIF":0.0,"publicationDate":"1988-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71361980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8