Journal of research of the National Bureau of Standards (1977)最新文献_第10页

Conference Report: FIBER OPTICS EMPHASIS ON SINGLE MODE. 会议报告:光纤强调单模。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1985-01-01 DOI: 10.6028/jres.090.004

Douglas L Franzen, Gordon W Day

引用次数: 0

Stable Law Densities and Linear Relaxation Phenomena. 稳定定律密度和线性松弛现象。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1985-01-01 DOI: 10.6028/jres.090.002

Menachem Dishon, George H Weiss, John T Bendler

{"title":"Stable Law Densities and Linear Relaxation Phenomena.","authors":"Menachem Dishon, George H Weiss, John T Bendler","doi":"10.6028/jres.090.002","DOIUrl":"https://doi.org/10.6028/jres.090.002","url":null,"abstract":"Stable law distributions occur in the description of the linear dielectric behavior of polymers, the motion of carriers in semi-conductors, the statistical behavior of neurons, and many other phenomena. No accurate tables of these distributions or algorithms for estimating the parameters in these relaxation models exist. In this paper we present tables of the functions <dispformula> <math> <mrow><msub><mi>Q</mi> <mi>α</mi></msub> <mo>(</mo> <mi>z</mi> <mo>)</mo> <mo>=</mo> <mfrac><mn>1</mn> <mi>π</mi></mfrac> <mrow><msubsup><mo>∫</mo> <mn>0</mn> <mi>∞</mi></msubsup> <mrow><msup><mi>e</mi> <mrow><mo>-</mo> <msup><mi>u</mi> <mi>α</mi></msup> </mrow> </msup> </mrow> </mrow> <mi>cos</mi> <mo>(</mo> <mi>z</mi> <mi>u</mi> <mo>)</mo> <mi>d</mi> <mi>u</mi></mrow> <mspace></mspace> <mrow><msub><mi>V</mi> <mi>α</mi></msub> <mo>(</mo> <mi>z</mi> <mo>)</mo> <mo>=</mo> <mfrac><mn>1</mn> <mi>π</mi></mfrac> <mrow><msubsup><mo>∫</mo> <mn>0</mn> <mi>∞</mi></msubsup> <mrow><msup><mi>e</mi> <mrow><mo>-</mo> <msup><mi>u</mi> <mi>α</mi></msup> </mrow> </msup> </mrow> </mrow> <mi>sin</mi> <mo>(</mo> <mi>z</mi> <mi>u</mi> <mo>)</mo> <mi>d</mi> <mi>u</mi></mrow> </math> </dispformula> together with related functional properties of zQ α (z). These are useful in the estimation of the parameters in relaxation models for polymers and related materials. Values of the integral Q α (z) are given for α = 0.01,0.02(0.02)0.1(0.1)1.0(0.2)2.0 and those of V α (z) are given for α = 0.0(0.01)0.1(0.1)2.0. A variety of methods was used to obtain six place accuracy. The tables can be used to sequentially estimate the three parameters appearing in the Williams-Watts model of relaxation. An illustration of this method applied to data in the literature is given.","PeriodicalId":93321,"journal":{"name":"Journal of research of the National Bureau of Standards (1977)","volume":"90 1","pages":"27-39"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6687585/pdf/jres-90-027.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39450925","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: 37

Indentation Fractography: A Measure of Brittleness. 压痕分形：脆性的一种测量方法。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1984-11-01 DOI: 10.6028/jres.089.024

B R Lawn, D B Marshall

引用次数: 16

Controlled Indentation Flaws for the Construction of Toughness and Fatigue Master Maps. 韧性和疲劳总图的控制压痕缺陷。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1984-11-01 DOI: 10.6028/jres.089.025

R F Cook, B R Lawn

{"title":"Controlled Indentation Flaws for the Construction of Toughness and Fatigue Master Maps.","authors":"R F Cook, B R Lawn","doi":"10.6028/jres.089.025","DOIUrl":"https://doi.org/10.6028/jres.089.025","url":null,"abstract":"A simple and economical procedure for accurate determinations of toughness and lifetime parameters of ceramics is described. Indentation flaws are introduced into strength test pieces, which are then taken to failure under specified stressing and environmental conditions. By controlling the size of the critical flaw, via the contact load, material characteristics can be represented universally on \"master maps\" without the need for statistical considerations. This paper surveys both the theoretical background and the experimental methodology associated with the scheme. The theory is developed for \"point\" flaws for dynamic and static fatigue, incorporating load explicitly into the analysis. A vital element of the fracture mechanics is the role played by residual contact stresses in driving the cracks to failure. Experimental data on a range of Vickers-indented glasses and ceramics are included to illustrate the power of the method as a means of graphic materials evaluation. It is demonstrated that basic fracture mechanics parameters can be measured directly from the slopes, intercepts and plateaus on the master maps, and that these parameters are consistent, within experimental error, with macroscopic crack growth laws.","PeriodicalId":93321,"journal":{"name":"Journal of research of the National Bureau of Standards (1977)","volume":"89 6","pages":"453-465"},"PeriodicalIF":0.0,"publicationDate":"1984-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6692285/pdf/jres-89-453.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39450920","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: 11

The Interactions of Composition and Stress in Crystalline Solids. 结晶固体中成分与应力的相互作用。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1984-11-01 DOI: 10.6028/jres.089.026

F C Larché, J W Cahn

引用次数: 0

Automated High-Temperature PVT Apparatus With Data for Propane. 带有丙烷数据的自动高温PVT装置。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1984-09-01 DOI: 10.6028/jres.089.021

G C Straty, A M F Palavra

引用次数: 29

Radio Propagation in a Coal Seam and the Inverse Problem. 煤层中的无线电传播及其反问题。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1984-09-01 DOI: 10.6028/jres.089.022

D A Hill

引用次数: 19

A Report on the National Bureau of Standards pH Standards. 国家标准局pH标准报告。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1984-09-01 DOI: 10.6028/jres.089.023

Y C Wu, W F Koch, G Marinenko

引用次数: 7

Evaluation of Some High-Temperature Platinum Resistance Thermometers. 一些高温铂电阻温度计的评价。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1984-09-01 DOI: 10.6028/jres.089.020

J P Evans

引用次数: 17

Thermal Expansion of Liquid Normal Hydrogen Between 18.8 and 22.2 K. 液态正氢在18.8和22.2K之间的热膨胀。

Journal of research of the National Bureau of Standards (1977) Pub Date : 1984-07-01 DOI: 10.6028/jres.089.019

L A Schwalbe, E R Grilly

引用次数: 5