摘要:

A magnetic balance of the Sucksmith ring type has been constructed. It is capable of a precision of 0.5 to 1% in measurements of displacement. The estimated maximum error in susceptibility measurements is 2%. This apparatus has been used to measure the temperature variation of the susceptibilities of chromium sulphate, hydrated and anhydrous, and of the nitrates of chromium, cobalt, and nickel. Measurements were made at several values of the magnetic field strength, so that a correction for small amounts of ferromagnetic impurity could be obtained. The reciprocals of the corrected specific susceptibilities were plotted against the absolute temperature. The intercepts on the temperature axis of the resulting straight lines gave the values of the Curie–Weiss constant. These values have been compared with those for other salts of the same ions. The effective Bohr magneton numbers were calculated and compared with theoretical values given by van Vleck.

ISSN:1923-4287    

DOI:10.1139/cjr50a-020

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The variational method is applied to the Milne problem with capture, to obtain, for the density and for the angular distribution, expressions which give quite accurate values and which have a relatively simple analytical form. Tables of the density and angular distribution are included. The extrapolation distances determined by the Variational Method agree to high accuracy with the exact values. The angular distribution determined by the Variational Method is shown to be accurate within 0.05% in all cases where exact results are available. Tables are also given for the density and angular distribution in the Milne problem with capture and constant production.

ISSN:1923-4287    

DOI:10.1139/cjr50a-021

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

"Dimensional analysis" is an established and venerable subject, associated with such names as Fourier, Maxwell, and Lord Rayleigh. But only a genius can obtain dependable results with it, a state of affairs that is caused by the vague intuitionalistic way in which the subject has always been presented. The purpose of this paper is to formulate a precise theory.Anidonor complete physical quantity is an entity with two attributes: quality and quantity. Formal rules are given for the manipulation of idons, and it is shown that they can be pictured as vectors ink-dimensional space. This geometrization is not necessary, of course, but it often gives added grasp of the subject; just as vector analysis is never necessary in physics, though it is often convenient. There are six practical applications of the theory, all of which are handled m a precise and dependable way by the geometric method.

ISSN:1923-4287    

DOI:10.1139/cjr50a-022

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The effect of anodic films on the total heat losses to still air from the surfaces of cylindrical aluminum containers maintained at temperatures between 23 °C. and 100 °C. has been studied by recording the power required to maintain the containers at various temperatures above ambient. Anodic coats of the order of 20 μ thick required increases in power of 43% to 60% at 30 °C. and 68% to 79% at 90 °C., the variations at any one temperature being due to variations in thickness and color of the coating. The emissivity coefficient for the clear anodic coats used is estimated from the data to be about 0.80.

ISSN:1923-4287    

DOI:10.1139/cjr50a-023

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

A nonlinear amplifier is described which has been used to drive an Esterline Angus 0–1 ma. recording galvanometer as part of the automatic recording apparatus set up for taking microwave antenna patterns. The amplifier output is approximately proportional to the logarithm of the input voltage, and permits plotting a 60 db. variation in input signal. The speed of response is limited by the galvanometer movement but is adequate for obtaining a pattern through 100 degrees of azimuth in about two minutes. The plotting accuracy is better than 1 db. if care is taken to check calibration frequently.

ISSN:1923-4287    

DOI:10.1139/cjr50a-024

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Problems associated with the thickness of ice sheets on Canadian lakes led the author to investigate mathematically the deflection of a loaded plate resting upon an elastic foundation. Certain simplifying assumptions, which appear to be not unreasonable, permit the solutions obtained to be applied to the strength of a floating ice sheet. Relations for maximum stress and maximum deflections in terms of known functions are derived, both for a concentrated load and a uniform load distributed over a circular area. The resulting expressions should be tested experimentally to determine their domain of validity. Owing to similarity of conditions, these results may also be applied to the design of concrete roadways and airport runways.

ISSN:1923-4287    

DOI:10.1139/cjr50a-025

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Two media separated by a plane interface and each filling an infinite half-space are considered. Neutrons come in infinite number from infinity in one medium and the neutron density vanishes at infinity; in the other medium. Isotropic scattering in the laboratory system of co-ordinates in both media is assumed and all neutrons are assumed to have the same speed. The angular distribution of neutrons emerging from either medium into the other is obtained in terms of the angular distribution of neutrons for the Milne problem, that is, the angular distribution of neutrons emerging from a scattering medium into a vacuum. The latter angular distribution is tabulated in the preceding paper by LeCaine.

ISSN:1923-4287    

DOI:10.1139/cjr50a-026

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

A comparison is made in this study between the δ-ray densities expected theoretically and those observed experimentally on charged particle tracks in Ilford G5 emulsions. The energies of δ-rays are determined here by means of grain-counting measurements and energy-loss considerations. Using this method of energy determination and the theoretical formula for δ-ray density, good agreement has been found with the experimental distributions on proton, μ-meson, deuteron, and α-particle tracks. The agreement is satisfactory both in absolute value and in the shape of the δ-ray density distribution. These results are considered to show that the δ-ray technique is suitable as an absolute method of charged particle identification in photographic emulsions.

ISSN:1923-4287    

DOI:10.1139/cjr50a-027

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Short-lived bursts of 10 cm. radiation from auroral displays have been received by radar equipment. The sources of continuous radiation from a partially ionized medium are briefly discussed. From a knowledge of the constants of the equipment used it is deduced that the power density at the receiver is at least 2 × 10−10watts per (meter)2, and it seems that the most likely source of this radiation is a plasma oscillation of the ionized volume associated with the auroral display. If this is so, the electron density in at least localized regions must be of the order 1011per cm.3

ISSN:1923-4287    

DOI:10.1139/cjr50a-028

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

It is shown that not only the rest-mass of the electron but its spin as well is carried by the surrounding electromagnetic field. The ratio of magnetic moment and angular momentum (g-factor) of the electron is determined. The law of conservation of angular momentum is checked.

ISSN:1923-4287    

DOI:10.1139/cjr50a-029

出版商:NRC Research Press    

年代:1950

数据来源: NRC