摘要:

Expressions are obtained for the instantaneous dependence of pressure upon radius within a collapsing cylindrical shell of incompressible liquid when subjected to (a) neither external nor internal pressure or to (b) an external pressure but no internal pressure. Dynamical considerations suggest that very high pressures and radial velocities should be reached.

ISSN:0021-8979    

DOI:10.1063/1.1699625

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

The temperature distribution in an electric coil winding is determined by solving the differential equations which apply to the system approximately. The maximum and average temperature rises are given for several types of windings. A distinction is made between small and large temperature rise; the treatment of the former neglects local changes in resistivity and thermal conductivity caused by the increase in temperature. A correction factor is computed to obtain the actual temperature rise from the much simpler calculations for the maximum temperature rise which would occur if the resistance were independent of temperature. It is found that non‐uniform windings, wound of several different wire sizes to minimize the resistance, exhibit the same temperature rise characteristics as conventional uniform windings of zero curvature.

ISSN:0021-8979    

DOI:10.1063/1.1699626

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

Experiments on the evaporation outgassing of antimony in vacuum and in an inert atmosphere show that an inert atmosphere is advantageous for outgassing antimony if loss of antimony by evaporation is intollerable. A simple theory based on well‐established kenetic theory considerations is given which may explain and did predict the results.

ISSN:0021-8979    

DOI:10.1063/1.1699627

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

A discussion of deflection defocusing is given to point out the two‐dimensional character of the focusing action of deflection fields. A photograph of spot distortion actually observed is shown. A brief theory of combined spherical and cylindrical lenses is given, and a method of spot correction based on the principle of ``beam predistortion'' is described. An electron gun used for such correction is shown and experimental results obtained with this gun are exhibited.

ISSN:0021-8979    

DOI:10.1063/1.1699628

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

The transmission of a plane elastic wave at oblique incidence through a stratified solid medium consisting of any number of parallel plates of different material and thickness is studied theoretically. The matrix method is used to systematize the analysis and to present the equations in a form suitable for computation.

ISSN:0021-8979    

DOI:10.1063/1.1699629

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

The integral‐equation theory of coupled antennas developed by King and Harrison, Tai and Bouwkamp for two‐ and three‐coupled antennas is generalized to any number of units symmetrically arranged around a circle. The case of four antennas at the corners of a square is discussed in detail. Application to cage and corner‐reflector antennas is indicated.The analysis ofNparallel antennas arranged in line is carried out to determine the driving voltages required to maintain specified currents. It is shown that the inverse problem cannot be carried out in general except as a problem in simultaneous integral equations, but that the special conditions obtaining for half‐wave dipoles permit an approximate analysis for the currents with given voltages. This is carried through.

ISSN:0021-8979    

DOI:10.1063/1.1699630

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

Dimensional analysis is used in a study of the behavior of metal when it is cut. Present theories are described and some additional significant variables are found. The analysis provides a basis for the interpretation of known experimental results, and should serve as a guide for future experimental and theoretical investigations.

ISSN:0021-8979    

DOI:10.1063/1.1699607

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

A theoretical study has been made of the initial electron flow when a signal voltageV(t) is applied across an idealized planar diode. The analysis is based upon three fundamental postulates: Poisson's equation, Newton's equation, and the continuity equation. This quasi‐stationary study includes both the growth and motion of the space‐charge cloud of electrons across the interelectrode space and the transient build‐up of the current in the external circuit. The analytical forms and numerical plots of the current build‐up under space‐charge‐limited and temperature‐limited operation are compared for various ``large'' and ``small'' signal voltages.

ISSN:0021-8979    

DOI:10.1063/1.1699608

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

The thermoelectric power of several refractory thermocouples was investigated, W‐Ta for temperature measurements up to 3000°C, W‐Mo up to 2600°C, Ta‐Mo up to 2600°C and W‐W/Mo (alloy 50 percent Mo/50 percent W) up to 2900°C.Basic calibration was carried out using several melting points and the results were verified and interpolated by means of an optical pyrometer.The couples W‐Ta and W‐Mo have been applied in this laboratory to the temperature measurement requirements in high temperature vacuum furnaces and determinations of spectral emissivity.

ISSN:0021-8979    

DOI:10.1063/1.1699609

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

The interaction between the electromagnetic field in a cavity and an electron beam projected along the axis of the cavity is examined. The particular cavity considered here is of the cylindrical TE11nztype in a steady axial magnetic field. If the cavity is excited in a linearly polarized mode, the electromagnetic field will drive the electrons in a helical trajectory with an expanding radius, and the electrons will excite and transfer energy to a degenerate mode oriented spatially at right angles to the driving field. In the driving plane of polarization (both planes of polarization if the cavity is excited in a circularly polarized mode), the electron beam will excite a field in phase opposition to the driving field in a manner analogous to the counter e.m.f. in an electromechanical generator. The converse case of a TE11nzcavity excited by a spiral beam of electrons is also considered.

ISSN:0021-8979    

DOI:10.1063/1.1699610

出版商:AIP    

年代:1950

数据来源: AIP