摘要:

Part I deals with the problem of determining the field due to a source of radiation inside a semi-infinite rectangular wave guide closed at one end by a plug, the current distribution in the source being regarded as known. Both the walls of the guide and the plug are treated as being perfectly conducting. Three different methods of solving the problem are given. The radiation resistance is then deduced from energy considerations. In particular, an expression for the radiation resistance of a linear antenna perpendicular to the wider face of the plug, fed at the point of entry, is derived, it being assumed that the antenna current is sinusoidal and that only the fundamentalH-wave is transmitted by the guide.In Part II, one of the methods of paper I is extended to the case of a guide ofarbitrarycross section, and the general problem of the calculation of radiation resistance and reactance is discussed.In Part III, a number of formulae for the radiation resistance of antennae of various shapes, with various assumed current distributions, in rectangular and circular guides, are given.In Part IV, explicit calculations for the impedance of a linear antenna in a rectangular wave guide are given. Further numerical calculations relating to the same problem, from the point of view of matching and sensitivity, have been made by Messrs. Chien and Pounder, but are not reproduced here.

ISSN:1923-4287    

DOI:10.1139/cjr49a-008

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr49a-009

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr49a-010

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr49a-011

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr49a-012

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

In this paper veiling glare is defined and its general aspects in aerial photography are discussed. Experimental results showing the effect of glare on the resolving power of a standard aerial film are presented in the form of graphs. A method of measurement is described and typical amounts encountered in widely used aerial cameras are given. From the results it is shown that veiling glare commonly causes a loss of photographic speed of as much as 100% where resolving power is the primary consideration. Recommendations are made for minimizing flare in cameras.

ISSN:1923-4287    

DOI:10.1139/cjr49a-013

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

By the simultaneous detection of thep, T, and He3particles in a thin window proportional counter the concurrent nuclear reactions D(d,p)T and D(d,n)He3have been investigated throughout the deuteron energy range 26 to 63 kev. The ratio of the yield of the reaction D(d,p)T to that of the reaction D(d,n)He3was found to be 1.15 ± 0.15 throughout this energy range. There is some slight evidence for an increase in this ratio towards lower bombarding energies.

ISSN:1923-4287    

DOI:10.1139/cjr49a-014

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

The heat capacities of gasoline, Napalm, and various Napalm–gasoline gels have been measured in the range − 50 °C. to 50 °C. by the method of mixtures, using an ordinary type of Richard's adiabatic calorimeter. The specific heat in calories per gram per Centigrade degree at a temperatureT°C. within this range is given to within 2% by the relationwhereCdenotes the Napalm concentration in per cent by weight. Concentrations of 0% and 100% are included. These data supplement earlier results on thermal conductivity.

ISSN:1923-4287    

DOI:10.1139/cjr49a-015

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Hyperfine structures have been observed in thetransitions of P IV with a 21 ft. concave grating and in thetransition of P III with a transmission echelon. The half-widths of the lines, excited in an electrodeless discharge, were reduced by mixing neon with the phosphorus vapor and by using a condenser of small capacity. Their intensities were increased by discharging the condenser through the exciting coil nine times per half-cycle by means of a rotating spark gap. The structures of the P IV lines confirmI = 1/2 and show that μ, the nuclear magnetic moment, is positive. μ = 1.15 ± 0.05 n.m. and μ = 1.11 ± 0.1 n.m. are obtained from the P IV and P III structures, respectively.

ISSN:1923-4287    

DOI:10.1139/cjr49a-016

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

An experiment has been performed to verify the gamma-ray energy spectrum of Radium (B + C) as reported by Latyshev and associates. The spectrum was obtained by measuring the energies of photoelectrons ejected from a thin lead radiator by means of a thin-lens magnetic beta-ray spectrometer. The spectrum obtained failed to reveal the presence of transitions other than those reported by C. D. Ellis. Comparative results are presented.

ISSN:1923-4287    

DOI:10.1139/cjr49a-017

出版商:NRC Research Press    

年代:1949

数据来源: NRC