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1. |
American Society for X‐Ray and Electron Diffraction |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 141-141
H. A. B.,
G. H. B.,
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ISSN:0021-8979
DOI:10.1063/1.1714846
出版商:AIP
年代:1942
数据来源: AIP
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2. |
X‐Ray Absorption Structure as a Tool in Physics and Chemistry |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 142-146
S. T. Stephenson,
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ISSN:0021-8979
DOI:10.1063/1.1714847
出版商:AIP
年代:1942
数据来源: AIP
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3. |
Relation Between Viscosity of Solutions and Physical Properties of High Polymers |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 147-153
Robert Simha,
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ISSN:0021-8979
DOI:10.1063/1.1714848
出版商:AIP
年代:1942
数据来源: AIP
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4. |
A Theoretical Approach to the Problem of Yarn Strength |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 157-167
R. R. Sullivan,
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摘要:
An idealized yarn composed of fibers with specified properties is treated analytically with the aim of determining the yarn strength at any degree of twist. The results are presented in the form of equations and curves which relate the yarn strength to the fiber properties and the degree of twist. Two cases are studied: (1) All fibers alike; (2) fiber properties variable from fiber to fiber. In the latter case the mathematical expectation of the yarn strength at any yarn cross section is obtained. It is found that the optimum twist multiplier is largely determined by the fiber length, fiber fineness, and coefficient of friction, whereas the maximum yarn strength (corresponding to the optimum twist multiplier) is more strongly dependent upon the intrinsic fiber strength than upon the other fiber properties studied.
ISSN:0021-8979
DOI:10.1063/1.1714849
出版商:AIP
年代:1942
数据来源: AIP
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5. |
An Extension of Saint‐Venant's Principle, with Applications |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 167-171
J. N. Goodier,
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摘要:
Simple energy considerations, which have previously been employed to provide a rational basis for the principle of Saint‐Venant, are shown to lead to the conclusion that forces applied in the neighborhood of a rigidly fixed portion of an elastic solid can cause only local stress and strain. This principle indicates useful features of certain problems encountered in engineering, and is used here in the calculation of the stiffness of a thin layer of elastic material confined between rigid plates, under any kind of load applied to the plates.
ISSN:0021-8979
DOI:10.1063/1.1714850
出版商:AIP
年代:1942
数据来源: AIP
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6. |
The Phase of Arcback |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 171-178
Albert W. Hull,
Frank R. Elder,
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摘要:
Thyratrons of FG‐41 type were tested at over‐voltage for arcback in a circuit which simulates operating conditions very closely. Memory oscillograms showed the time in the cycle at which the arcbacks occurred. At a mercury‐control temperature of 45°C, the distribution was nearly random, with a maximum at the time of highest negative anode voltage, and depending on voltage in the same manner as the average arcback rate, taken over a long period. When the mercury‐control temperature was raised to 64°C, all the arcbacks occurred at the beginning of negative voltage application. These results are interpreted on the theory recently advanced by Kingdon and Lawton, which attributes arcback to charging up of small non‐conducting particles on the surface of the anode. At low vapor pressure, where the ions remaining from the discharge have time to diffuse to the electrodes before negative voltage is applied, the charging is produced by processes such as glow discharge and field emission, which depend on voltage; hence arcback is correlated with voltage. At higher pressure, diffusion is interfered with by molecular collision, so that ions are present when negative voltage is applied. In this condition arcback occurs at the beginning of the negative cycle.
ISSN:0021-8979
DOI:10.1063/1.1714851
出版商:AIP
年代:1942
数据来源: AIP
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7. |
The Depth Dependence of Earth Conductivity Upon Surface Potential Data |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 179-188
W. G. Keck,
W. F. Colby,
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摘要:
The problem of determining electrical earth conductivity from the surface, in the case where it is a function of the depth only, is solved by a perturbation method, which formally at least, allows the unperturbed functions to be perfectly arbitrary. Numerical work, however, is restricted to those functions which are available as solutions of the so‐called ``inverse'' problem, a group of which is given. Of this group the case in which the unperturbed conductivity varies exponentially is treated in detail and two examples showing the success of the method are presented. A numerical method of solving integral equations of the Laplace type, which occur in the above, is also submitted.
ISSN:0021-8979
DOI:10.1063/1.1714852
出版商:AIP
年代:1942
数据来源: AIP
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8. |
Large Scale Extraction of Polonium from Active Lead and Formation of Radioactive Electrode Alloys |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 189-198
J. H. Dillon,
J. N. Street,
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摘要:
Various possible sources of Po for industrial use are discussed and reasons for selection of active lead salts for this purpose are given. Methods of measurement of the amounts of Po present on plated metal foils and in electrode alloy are described. The RaD/Pb ratio was found to vary from 1.2×10−8to 1.9×10−8for various samples of active lead from the Great Bear Lake region. Methods for extraction of Po from active lead salts are discussed and a large scale plating method is described. Results of experiments on the rate of Po‐plating from boiling solutions of active lead salts as related to the acid concentration, exposed foil area, foil composition, etc., are presented. Chemical methods for producing soluble active lead salts are described.A method of introducing Po into electrode alloy is described. In a typical experiment, it was found that 94 percent of the Po introduced into the melt was retained in the final alloy. Contact radiographs of electrode alloy samples showing the affect of various heat treatments and surface condition are presented.
ISSN:0021-8979
DOI:10.1063/1.1714854
出版商:AIP
年代:1942
数据来源: AIP
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9. |
Streamering in Negative Corona |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 199-200
Willard H. Bennett,
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摘要:
Corona from sharp points in air can be divided into two ranges, a diffuse range and a streamering range, this division being applicable for each polarity of discharge although the details are different for the two polarities.
ISSN:0021-8979
DOI:10.1063/1.1714855
出版商:AIP
年代:1942
数据来源: AIP
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10. |
On Relaxation Effects in Amorphous Media |
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Journal of Applied Physics,
Volume 13,
Issue 3,
1942,
Page 201-207
Robert Simha,
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摘要:
The Maxwell relaxation theory leading to the concept of a viscous‐elastic body is briefly stated. Extensions to systems built up from several such viscous‐elastic components with different relaxation times are discussed. In the case of high molecular weight materials, it is more appropriate to assume a continuous distribution of relaxation rates. Equations are formulated whose solution gives the distribution function in terms of the rate of deformation and of the applied stress or the elongation in terms of the two other quantities. The connection with the corresponding distribution of dielectric relaxation times, molecular inhomogeneity and chain branching, and effects at mechanical frequencies large compared with the relaxation rates, are pointed out.
ISSN:0021-8979
DOI:10.1063/1.1714856
出版商:AIP
年代:1942
数据来源: AIP
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