Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry最新文献_第10页

Investigation of Freezing Temperatures of National Bureau of Standards Aluminum Standards. 国家标准局铝标准冻结温度调查。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-07-01 DOI: 10.6028/jres.078A.031

George T Furukawa

{"title":"Investigation of Freezing Temperatures of National Bureau of Standards Aluminum Standards.","authors":"George T Furukawa","doi":"10.6028/jres.078A.031","DOIUrl":"10.6028/jres.078A.031","url":null,"abstract":"The design of a high-precision furnace for investigating the freezing points of metals up to 700 °C or higher is described. The freezing points of aluminum samples of nominally 99.999 percent purity from two batches were compared in terms of the ratio R(Al)/R(TP), the ratio of the resistance of the platinum resistance thermometer at the aluminum freezing point to that at the triple point of water. The average standard deviation of measurements of the ratio R(Al)/R(TP) obtained on six specimens corresponds to ±0.40 mK, while the average standard deviations of R(Al) and R(TP) correspond to ±0.17 mK and ±0.14 mK, respectively. (The variations in the measurements of R(TP) are amplified by 3.4 in the ratio R(Al)/R(TP).) The spread of the mean R(Al)/R(TP) obtained for five out of the six specimens corresponds to 0.51 mK; the deviation of the mean R(Al)/R(TP) of the sixth specimen from the mean R(Al)/R(TP) of the five specimens corresponds to -1.31 mK. (The sixth specimen may have been contaminated during the assembly of the freezing-point cell or the original sample bar was inhomogeneous.) The results show that aluminum can provide a freezing point (near 660 °C) that is at least as reproducible as the freezing point of antimony (near 631 °C).","PeriodicalId":17018,"journal":{"name":"Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry","volume":"78A 4","pages":"477-495"},"PeriodicalIF":0.0,"publicationDate":"1974-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742808/pdf/jres-78A-477.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37751293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Standardization of ⁶⁰Co and ¹³⁷Cs Gamma-Ray Beams in Terms of Exposure. 辐照条件下60Co和137Cs伽玛射线束的标准化。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-07-01 DOI: 10.6028/jres.078A.030

T P Loftus, J T Weaver

{"title":"Standardization of 60Co and 137Cs Gamma-Ray Beams in Terms of Exposure.","authors":"T P Loftus, J T Weaver","doi":"10.6028/jres.078A.030","DOIUrl":"10.6028/jres.078A.030","url":null,"abstract":"At the National Bureau of Standards (NBS), the exposure-rate standards for 60Co and 137Cs gamma rays were based for a number of years on a weighted average of measurements using a cylindrical ionization chamber and a group of small spherical chambers. Complex setup conditions for the cylindrical chamber, differences between the cylindrical and spherical chamber data, and recognition that the institution of this weighted average exposure-rate standard increased the difference between free-air-chamber and cavily-chamber measurements, led to the development of new spherical chambers. All correction factors for exposure-rate measurements were investigated and updated. Excellent agreement was achieved between independent exposure-rate measurements for six spherical chambers and, as of May 1, 1972, the exposure standards were reduced 0.7 percent for 60Co and 0.6 percent for 137Cs gamma rays. Recalculation of correction factors since that time indicates that the standard 137Cs should be further reduced by 0.2 percent, and this adjustment was made on July 1, 1974. The uncertainties associated with each of the quantities entering into the determination of exposure rate were tabulated and the overall uncertainty of the exposure rates used for instrument calibrations at NBS was found to be about 0.7 percent for addition in quadrature.","PeriodicalId":17018,"journal":{"name":"Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry","volume":"78A 4","pages":"465-476"},"PeriodicalIF":0.0,"publicationDate":"1974-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742815/pdf/jres-78A-465.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37751299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 60

The Glass Transition Temperature of Monodispersed Polystyrenes and Their Binary Mixtures. 单分散聚苯乙烯及其二元混合物的玻璃化转变温度。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-07-01 DOI: 10.6028/jres.078A.027

Leo A Wall, Roestamsjah, Mary H Aldridge

引用次数: 16

Theoretical and Experimental Compton Scattering Cross Sections at 1.12 MeV in the Case of Strongly Bound K-Shell Electrons. 强束缚k壳层电子在1.12 MeV下的理论和实验康普顿散射截面。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-07-01 DOI: 10.6028/jres.078A.029

P N Baba Prasad, P P Kane

引用次数: 1

Analysis of Low Temperature Viscosity Data for Three NBS Standard Glasses. 三种NBS标准玻璃的低温粘度数据分析。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-05-01 DOI: 10.6028/jres.078A.017

A Napolitano, J H Simmons, D H Blackburn, R E Chidester

引用次数: 26

PVT Relationships for Liquid and Glassy Poly(vinyl acetate). 液体和玻璃状聚（乙酸乙烯酯）的PVT关系。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-05-01 DOI: 10.6028/jres.078A.018

John E McKinney, Martin Goldstein

{"title":"PVT Relationships for Liquid and Glassy Poly(vinyl acetate).","authors":"John E McKinney, Martin Goldstein","doi":"10.6028/jres.078A.018","DOIUrl":"10.6028/jres.078A.018","url":null,"abstract":"PVT measurements were made on liquid and glassy poly(vinyl acetate) over ranges of -30 to 100 °C and 0 to 800 bar (gage pressure). The data were obtained by three different thermodynamic histories: (a) variable formation pressure, (b) constant formation pressure at one atmosphere, and (c) constant formation pressure at 800 bar. In all of these the glass was formed by isobaric cooling at 5 °C/h. The salient characteristics resulting from the different histories are the following. History (a) produces a glass of structure varying with formation pressure and, hence, does not necessarily give the proper thermodynamic properties of a \"single physical substance.\" However, the liquid-glass intersection temperature, T g (P), is an important kinetic, or relaxational, property which approximates an isoviscous state. Accordingly, the values of dT g /dP are in close agreement with those obtained from dynamic mechanical and dielectric time-temperature-pressure superposition. Constant formation histories (b) and (c) give proper thermodynamic properties of the glasses, but very little information with respect to kinetics. Increasing the pressure at which the glass is formed increases the density of the glass (at the given cooling rate) considerably in contrast to the entropy (from other work), which appears to be essentially independent of formation pressure. A considerable part of the paper is definitional. The results are related to other PVT, dynamic mechanical, dielectric, and thermodynamic measurements. Interpretations are given in terms of both phenomenological and molecular models.","PeriodicalId":17018,"journal":{"name":"Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry","volume":"78A 3","pages":"331-353"},"PeriodicalIF":0.0,"publicationDate":"1974-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742822/pdf/jres-78A-331.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37752940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 126

The Formation of Curved Polymer Crystals: Polychlorotrifluoroethylene. 弯曲聚合物晶体的形成：聚氯三氟乙烯。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-05-01 DOI: 10.6028/jres.078A.020

J D Barnes, F Khoury

引用次数: 15

The Infrared Spectra of Matrix Isolated Uranium Oxide Species. 基质分离氧化铀的红外光谱。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-05-01 DOI: 10.6028/jres.078A.026

S Abramowitz, N Acquista

引用次数: 8

Correction and Extension of van der Poel's Method for Calculating the Shear Modulus of a Particulate Composite. 计算颗粒复合材料剪切模量的van der Poel方法的修正与推广。

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-05-01 DOI: 10.6028/jres.078A.019

Jack C Smith

引用次数: 117

Photoionization of CO₂ -CO-O₂ Mixtures. Formation and Reactions of Ion Clusters. CO2 -CO-O2 混合物的光离子化。离子簇的形成和反应

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry Pub Date : 1974-05-01 DOI: 10.6028/jres.078A.016

L W Sieck, R Gorden

{"title":"Photoionization of CO2 -CO-O2 Mixtures. Formation and Reactions of Ion Clusters.","authors":"L W Sieck, R Gorden","doi":"10.6028/jres.078A.016","DOIUrl":"10.6028/jres.078A.016","url":null,"abstract":"Various mixtures containing combinations of CO2, O2, or CO have been photoionized at 16.7 and 21.2 eV at pressures up to 1.5 torr in the NBS high pressure photoionization mass spectrometer. In CO2-CO mixtures the interactions of <math> <mrow> <msubsup><mrow><mtext>CO</mtext></mrow> <mn>2</mn> <mo>+</mo></msubsup> </mrow> </math> ions eventually lead to the formation of <math> <mrow> <msubsup><mrow><mtext>(CO)</mtext></mrow> <mn>2</mn> <mo>+</mo></msubsup> </mrow> </math> and [(CO)2-CO2]+ cluster ions, while photoionization of CO2-CO-O2 mixtures yields mainly oxygen-containing clusters at higher pressures. The investigation of O2-CO mixtures also revealed reactions between <math> <mrow><msubsup><mtext>O</mtext> <mn>4</mn> <mo>+</mo></msubsup> </mrow> </math> and CO. The role of impurity reactions involving H2O is considered in some detail, and the implications of all of these data to the vapor phase radiolysis of CO2 is discussed.","PeriodicalId":17018,"journal":{"name":"Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry","volume":"78A 3","pages":"315-322"},"PeriodicalIF":0.0,"publicationDate":"1974-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742819/pdf/jres-78A-315.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37751972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0