The ion-neutralization spectroscopy (INS) is discussed in comparison with other spectroscopies of solids. It is shown that INS probes the local density of states of the solid at or just outside the solid surface. It is believed that this accounts for the clear-cut differences between INS results and those of other spectroscopies. Because of its unique specificity to the surface region INS is particularly useful in studying the surface electronic structures of atomically clean surfaces and of surfaces having ordered arrays of known atoms adsorbed upon them. In the latter case INS determines a portion of the molecular orbital spectrum of surface molecules formed from the adsorbed foreign atom and surface atoms of the bulk crystal. Such spectra provide information on local bonding symmetry and structure and electrical charging within the surface molecule which is as yet unavailable by any other method. INS is the first attempt to base a spectroscopy of electronic states on a two-electron process. More recent work on experimental and mathematical problems which such a spectroscopy entails are also briefly mentioned in this paper.
{"title":"Ion-Neutralization Spectroscopy.","authors":"H. D. Hagstrum","doi":"10.1116/1.1315830","DOIUrl":"https://doi.org/10.1116/1.1315830","url":null,"abstract":"The ion-neutralization spectroscopy (INS) is discussed in comparison with other spectroscopies of solids. It is shown that INS probes the local density of states of the solid at or just outside the solid surface. It is believed that this accounts for the clear-cut differences between INS results and those of other spectroscopies. Because of its unique specificity to the surface region INS is particularly useful in studying the surface electronic structures of atomically clean surfaces and of surfaces having ordered arrays of known atoms adsorbed upon them. In the latter case INS determines a portion of the molecular orbital spectrum of surface molecules formed from the adsorbed foreign atom and surface atoms of the bulk crystal. Such spectra provide information on local bonding symmetry and structure and electrical charging within the surface molecule which is as yet unavailable by any other method. INS is the first attempt to base a spectroscopy of electronic states on a two-electron process. More recent work on experimental and mathematical problems which such a spectroscopy entails are also briefly mentioned in this paper.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"74 3 1","pages":"433-441"},"PeriodicalIF":0.0,"publicationDate":"1970-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84677586","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}
Certain polycyclic, aromatic hydrocarbons can be oxidized with periodic acid in aprotic solvents containing a small proportion of water. A unique, two-fold character of response to periodic acid by these hydrocarbons has been found: (1) production of a coupling reaction through a radical intermediate [conversion of pyrene into 1,1'-bipyrene, and fluorene into 1,2-bis(2,2'-biphenylylene)ethylene] or (2) conversion into quinones by a two-equivalent oxidation mechanism that does not involve a radical intermediate [acenaphthene, anthracene, anthrone, benz[a]anthracene, naphthacene, naphthalene, and phenanthrene]. Little or no reaction was observed when oxidation was attempted with sodium metaperiodate instead of periodic acid. Electron-spin resonance revealed no radical intermediate in the oxidation of malonic acid with either periodic acid or sodium periodate.
{"title":"Periodic Acid, a Novel Oxidant of Polycyclic, Aromatic Hydrocarbons.","authors":"A. Fatiadi","doi":"10.1039/C19670001087","DOIUrl":"https://doi.org/10.1039/C19670001087","url":null,"abstract":"Certain polycyclic, aromatic hydrocarbons can be oxidized with periodic acid in aprotic solvents containing a small proportion of water. A unique, two-fold character of response to periodic acid by these hydrocarbons has been found: (1) production of a coupling reaction through a radical intermediate [conversion of pyrene into 1,1'-bipyrene, and fluorene into 1,2-bis(2,2'-biphenylylene)ethylene] or (2) conversion into quinones by a two-equivalent oxidation mechanism that does not involve a radical intermediate [acenaphthene, anthracene, anthrone, benz[a]anthracene, naphthacene, naphthalene, and phenanthrene]. Little or no reaction was observed when oxidation was attempted with sodium metaperiodate instead of periodic acid. Electron-spin resonance revealed no radical intermediate in the oxidation of malonic acid with either periodic acid or sodium periodate.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"10 1","pages":"341-350"},"PeriodicalIF":0.0,"publicationDate":"1968-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90835969","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}
In 1934, Gibson, Walker, and Brown developed sets of four colored glass filters to serve as working standards of spectral transmittance for checking the reliability of spectrophotometers. Several sets of these glasses were measured carefully and reserved and designated as future reference standards. Duplicate standards evaluated by comparison with the reference standards are available by purchase to the public. The current set of reference standards was established in the years 1945 to 1947, and one of these reference standards (selenium-red) was recalibrated in 1952. This paper reports a recalibration, made in 1961 and 1962, of all four glasses (selenium-red, carbon-yellow, copper-green, cobalt-blue) on three spectrophotometers (Cary 14, Beckman DU, König-Martens). Except for the cobalt-blue standard, the values of spectral transmittance found differ from those previously assigned by amounts differing at some wavelengths by as much as or slightly more than the uncertainties estimated for the present values, though not by amounts exceeding the combined uncertainties of the present and previous determinations. The indicated changes for these three standards are fairly regular, however, and support the view that the selenium-red and carbon-yellow standards are changing chiefly by formation of a reflectance-reducing film on the surfaces. The indicated rate of upward drift is slow, and suggests that it takes about 10 years for the drift to exceed the assigned uncertainity.
1934年，Gibson, Walker和Brown开发了一套四种彩色玻璃滤光片，作为检查分光光度计可靠性的光谱透射率的工作标准。有几套这样的玻璃杯被仔细地测量过，并保留下来作为将来的参考标准。通过与参考标准比较评估的重复标准可向公众购买。目前的一套参考标准是在1945年至1947年建立的，其中一个参考标准(硒红)于1952年重新校准。本文报告了1961年和1962年在三个分光光度计(Cary 14, Beckman DU, König-Martens)上对所有四种玻璃(硒红，碳黄，铜绿，钴蓝)进行的重新校准。除了钴蓝标准外，所发现的光谱透过率值与先前的值不同，在某些波长上的差异与当前值估计的不确定度相差相同或略大，但不超过当前和以前测定的不确定度总和。然而，这三种标准的变化是相当有规律的，这支持了硒红和碳黄标准的变化主要是由于表面上形成了一层减少反射的薄膜。所指示的向上漂移的速率是缓慢的，并且表明漂移需要大约10年的时间才能超过指定的不确定度。
{"title":"Recalibration of the NBS Glass Standards of Spectral Transmittance1","authors":"H. J. Keegan, J. C. Schleter, M. Belknap","doi":"10.6028/jres.067A.056","DOIUrl":"https://doi.org/10.6028/jres.067A.056","url":null,"abstract":"In 1934, Gibson, Walker, and Brown developed sets of four colored glass filters to serve as working standards of spectral transmittance for checking the reliability of spectrophotometers. Several sets of these glasses were measured carefully and reserved and designated as future reference standards. Duplicate standards evaluated by comparison with the reference standards are available by purchase to the public. The current set of reference standards was established in the years 1945 to 1947, and one of these reference standards (selenium-red) was recalibrated in 1952. This paper reports a recalibration, made in 1961 and 1962, of all four glasses (selenium-red, carbon-yellow, copper-green, cobalt-blue) on three spectrophotometers (Cary 14, Beckman DU, König-Martens). Except for the cobalt-blue standard, the values of spectral transmittance found differ from those previously assigned by amounts differing at some wavelengths by as much as or slightly more than the uncertainties estimated for the present values, though not by amounts exceeding the combined uncertainties of the present and previous determinations. The indicated changes for these three standards are fairly regular, however, and support the view that the selenium-red and carbon-yellow standards are changing chiefly by formation of a reflectance-reducing film on the surfaces. The indicated rate of upward drift is slow, and suggests that it takes about 10 years for the drift to exceed the assigned uncertainity.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"31 1","pages":"577 - 584"},"PeriodicalIF":0.0,"publicationDate":"1963-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84391777","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}
The complete characterization of batch adsorption from solution, desorption, and related phenomena have been interpreted in the light of a general equation. The forward and reverse adsorption-rate constants and the adsorptive capacity comprise the only parameters. Where adsorption alone is of importance and the desorption-rate constant can be neglected, a simplified form of the theory results in a special equation which may suffice for most adsorption purposes. In either case, the characteristic parameters are determinable from the data and serve as criteria for comparing similar systems. The theory has been confirmed by the data of various investigators taken from the literature. The parameters derived from column adsorption are in agreement with the corresponding batch-derived parameters. The limitations as well as the capabilities of the theory are presented; but even where deviations from the assumed model exist, the results are useful.
{"title":"Adsorption, Desorption, Resorption","authors":"W. V. Loebenstein","doi":"10.6028/jres.067A.061","DOIUrl":"https://doi.org/10.6028/jres.067A.061","url":null,"abstract":"The complete characterization of batch adsorption from solution, desorption, and related phenomena have been interpreted in the light of a general equation. The forward and reverse adsorption-rate constants and the adsorptive capacity comprise the only parameters. Where adsorption alone is of importance and the desorption-rate constant can be neglected, a simplified form of the theory results in a special equation which may suffice for most adsorption purposes. In either case, the characteristic parameters are determinable from the data and serve as criteria for comparing similar systems. The theory has been confirmed by the data of various investigators taken from the literature. The parameters derived from column adsorption are in agreement with the corresponding batch-derived parameters. The limitations as well as the capabilities of the theory are presented; but even where deviations from the assumed model exist, the results are useful.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"1 1","pages":"615 - 624"},"PeriodicalIF":0.0,"publicationDate":"1963-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83747743","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}
A study has been made of the application of the gas-stabilized arc source to the determination of oscillator strengths in atomic spectra. In this source, a solution of salts of one or more elements may be injected and the elements excited directly in an arc plasma with steady emission of spectral intensities. The source can be taken to be characterized by local thermal equilibrium, but with a large radial temperature gradient. An experiment indicates that when two elements are introduced into the arc in a solution, the relative concentrations of the elements in the discharge are the same as in the solution within the probable experimental error. This experiment indicates one way that the arc may be used for the determination of absolute oscillator strengths. New measurements are reported of the gf-values of 105 lines of Fe I between 2900 and 4150 Å, and the new values are compared with the results of earlier measurements.
{"title":"A Study of the Gas-Stabilized Arc as an Emission Source for the Measurement of Oscillator Strengths. Determination of Some Relative gf-Values for Fe I*","authors":"M. Margoshes, B. F. Scribner","doi":"10.6028/jres.067A.053","DOIUrl":"https://doi.org/10.6028/jres.067A.053","url":null,"abstract":"A study has been made of the application of the gas-stabilized arc source to the determination of oscillator strengths in atomic spectra. In this source, a solution of salts of one or more elements may be injected and the elements excited directly in an arc plasma with steady emission of spectral intensities. The source can be taken to be characterized by local thermal equilibrium, but with a large radial temperature gradient. An experiment indicates that when two elements are introduced into the arc in a solution, the relative concentrations of the elements in the discharge are the same as in the solution within the probable experimental error. This experiment indicates one way that the arc may be used for the determination of absolute oscillator strengths. New measurements are reported of the gf-values of 105 lines of Fe I between 2900 and 4150 Å, and the new values are compared with the results of earlier measurements.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"111 1","pages":"561 - 568"},"PeriodicalIF":0.0,"publicationDate":"1963-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77860908","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}
The matrices of spin-orbit interaction in the p2 p and p4 p electron configurations have been calculated. The matrices have been checked by showing that their eigenvalues, calculated by use of an IBM 7090, agree with the correct eigenvalues known from the theory of jj-coupling. For the sake of completeness, the matrices of electrostatic interaction for these configurations are also given.
{"title":"Matrices of Spin-Orbit Interaction in the Electron Configurations np2 n′ p and np4 n′ p","authors":"J. Tech","doi":"10.6028/jres.067A.052","DOIUrl":"https://doi.org/10.6028/jres.067A.052","url":null,"abstract":"The matrices of spin-orbit interaction in the p2 p and p4 p electron configurations have been calculated. The matrices have been checked by showing that their eigenvalues, calculated by use of an IBM 7090, agree with the correct eigenvalues known from the theory of jj-coupling. For the sake of completeness, the matrices of electrostatic interaction for these configurations are also given.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"35 1","pages":"555 - 559"},"PeriodicalIF":0.0,"publicationDate":"1963-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80859537","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}
The stereochemistry of catenanes, knotted molecules, and Borromean rings is discussed. An augmentation of the Cahn-Ingold-Prelog convention for designating absolute configuration is proposed. A convention is proposed for designating the absolute configuration of knotted molecules. A suggestion is made concerning the citing of the absolute configuration of molecularly dissymmetric diastereomers.
{"title":"Absolute Configuration and Chemical Topology","authors":"S. J. Tauber","doi":"10.6028/jres.067A.058","DOIUrl":"https://doi.org/10.6028/jres.067A.058","url":null,"abstract":"The stereochemistry of catenanes, knotted molecules, and Borromean rings is discussed. An augmentation of the Cahn-Ingold-Prelog convention for designating absolute configuration is proposed. A convention is proposed for designating the absolute configuration of knotted molecules. A suggestion is made concerning the citing of the absolute configuration of molecularly dissymmetric diastereomers.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"44 1","pages":"591 - 599"},"PeriodicalIF":0.0,"publicationDate":"1963-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84575290","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}
Giving greatest weight to the experimentally measured highest decomposition pressures and the enthalpies in one-phase fields, thermodynamically interconsistent integral and differential enthalpies (heat contents), heat capacities, entropies, and Gibbs free energies are derived for the crystalline one- and two-phase fields of the zirconium-hydrogen system for all stoichiometric compositions from Zr to ZrH1.25 and over the temperature range 298.15 to 1,200 °K. These properties are derived in analytical form, and in most cases are represented by numerical equations, with tabulation for zirconium and H/Zr atom ratios of 0.25, 0.50, 0.57, 0.75, 1.00, and 1.25. Most of the unique phase-field boundaries which are consistent with the derived properties are located and are compared with those previously reported. In the Zr-H system the enthalpies are shown to relate certain properties at different compositions as well as at different temperatures. Some of the various data show good interconsistency, while others reveal discrepancies which are discussed critically.
{"title":"High-Temperature Thermodynamic Functions for Zirconium and Unsaturated Zirconium Hydrides","authors":"T. Douglas","doi":"10.6028/jres.067A.043","DOIUrl":"https://doi.org/10.6028/jres.067A.043","url":null,"abstract":"Giving greatest weight to the experimentally measured highest decomposition pressures and the enthalpies in one-phase fields, thermodynamically interconsistent integral and differential enthalpies (heat contents), heat capacities, entropies, and Gibbs free energies are derived for the crystalline one- and two-phase fields of the zirconium-hydrogen system for all stoichiometric compositions from Zr to ZrH1.25 and over the temperature range 298.15 to 1,200 °K. These properties are derived in analytical form, and in most cases are represented by numerical equations, with tabulation for zirconium and H/Zr atom ratios of 0.25, 0.50, 0.57, 0.75, 1.00, and 1.25. Most of the unique phase-field boundaries which are consistent with the derived properties are located and are compared with those previously reported. In the Zr-H system the enthalpies are shown to relate certain properties at different compositions as well as at different temperatures. Some of the various data show good interconsistency, while others reveal discrepancies which are discussed critically.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"63 1","pages":"403 - 426"},"PeriodicalIF":0.0,"publicationDate":"1963-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89215601","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}
As part of a program to determine accurately the heats of combustion of specialized fuels in the kerosene range, seven hydrocarbons, biphenyl, bicyclohexyl, cyclohexylbenzene, n-hexylbenzene, n-hexylcyclohexane, 1-cyclopentylheptane, and n-dodecane were synthesized or purified from commercial material. Physical constants were determined on the purified samples. These materials may have use as secondary standards for heat of combustion measurements.
{"title":"Synthesis, Purification, and Physical Properties of Seven Twelve-Carbon Hydrocarbons","authors":"T. Mears, C. L. Stanley, E. L. Compere, F. Howard","doi":"10.6028/jres.067A.049","DOIUrl":"https://doi.org/10.6028/jres.067A.049","url":null,"abstract":"As part of a program to determine accurately the heats of combustion of specialized fuels in the kerosene range, seven hydrocarbons, biphenyl, bicyclohexyl, cyclohexylbenzene, n-hexylbenzene, n-hexylcyclohexane, 1-cyclopentylheptane, and n-dodecane were synthesized or purified from commercial material. Physical constants were determined on the purified samples. These materials may have use as secondary standards for heat of combustion measurements.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"274 1","pages":"475 - 479"},"PeriodicalIF":0.0,"publicationDate":"1963-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79999541","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}
This paper considers the resolution limits of those analyzers and oscillatory systems whose performance may be represented by a second-order differential equation. The “signal uncertainty” product Δf·Δt is shown to be controlled by the ability of a system to indicate changes in energy content. The discussion refers the functioning of the system to a signal space whose coordinates are energy, frequency, and time. In this signal space, the product of the resolution limits, U = (ΔE/E0) (Δf/f0) (Δt/T0) is the volume of a region within which no change of state in the system may be observed. Whereas the area element Δf·Δt is freely deformable, no operations upon either Δf or Δt can further the reduction of the energy resolution limit. Thus U is irreducibly fixed by the limiting value of ΔE/E0. By considering the effects of noise upon ΔE/E0, and thus upon U, the paper demonstrates the rise of statistical features as signal-to-noise ratios decrease. Functional relationships derived from ΔE/E0 and U are tabulated. These equations facilitate computation of the limits of observable changes of state in a system, and they provide guidance for the design of experiments to apportion the uncertainties of measurement of transient phenomena as advantageously as possible. A reference bibliography and appendices giving somewhat detailed proofs are included.
{"title":"Resolution Limits of Analyzers and Oscillatory Systems","authors":"E. Corliss","doi":"10.6028/jres.067A.048","DOIUrl":"https://doi.org/10.6028/jres.067A.048","url":null,"abstract":"This paper considers the resolution limits of those analyzers and oscillatory systems whose performance may be represented by a second-order differential equation. The “signal uncertainty” product Δf·Δt is shown to be controlled by the ability of a system to indicate changes in energy content. The discussion refers the functioning of the system to a signal space whose coordinates are energy, frequency, and time. In this signal space, the product of the resolution limits, U = (ΔE/E0) (Δf/f0) (Δt/T0) is the volume of a region within which no change of state in the system may be observed. Whereas the area element Δf·Δt is freely deformable, no operations upon either Δf or Δt can further the reduction of the energy resolution limit. Thus U is irreducibly fixed by the limiting value of ΔE/E0. By considering the effects of noise upon ΔE/E0, and thus upon U, the paper demonstrates the rise of statistical features as signal-to-noise ratios decrease. Functional relationships derived from ΔE/E0 and U are tabulated. These equations facilitate computation of the limits of observable changes of state in a system, and they provide guidance for the design of experiments to apportion the uncertainties of measurement of transient phenomena as advantageously as possible. A reference bibliography and appendices giving somewhat detailed proofs are included.","PeriodicalId":94340,"journal":{"name":"Journal of research of the National Bureau of Standards. Section A, Physics and chemistry","volume":"7 1","pages":"461 - 474"},"PeriodicalIF":0.0,"publicationDate":"1963-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74711838","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}
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