ISSN:0021-8979    

DOI:10.1063/1.1745047

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

A Bragg type ionization x‐ray spectrometer which was designed for making quantitative measurements of integrated x‐ray intensities reflected from crystals is described. The essential feature of the design is that the ionization chamber is fixed in position, thus allowing a short fixed connection between ion chamber and electrometer (Hoffman). The ion chamber and x‐ray tube used with the instrument are described.

ISSN:0021-8979    

DOI:10.1063/1.1745048

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

A vacuum tube was constructed having a filament and slit arrangement for the production of a sheet of electrons, one pair of deflecting plates, and a receiving plate composed of a series of rectangular conductors. Adjacent conductors were insulated from one another and alternate conductors were in electrical connection. An alternating potential difference applied to the deflecting plates causes the electron beam to move across the surface of the receiving plate, current flowing first to one set of conductors and then to the other set. During one complete cycle of the deflecting plate field, the currents from the two sets of conductors will pulsate with frequencies which are multiples of the frequency applied to the deflecting plates. By applying steady potentials to the deflecting plates, the current to each set of conductors may be measured and plotted as a function of the deflecting plate potential difference. Such static characteristic curves were examined for widely different currents, potentials, and gas content of the tube. Tests with an alternating potential difference applied to the deflecting plates gave very definite indications of receiving plate currents of two, four, and six times the frequency of the applied field.

ISSN:0021-8979    

DOI:10.1063/1.1745049

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

It is mathematically proven that a detector tube which has a broken straight line for its plate current‐grid voltage static characteristic will detect the standard radio signal without distortion, regardless of signal strength. The plate detection performance of a tube having a given curve for its static characteristic can be calculated from the extended power series which represents the characteristic. The power series analysis of the curve is obtained from a Fourier series analysis by a method which saves labor and is more accurate than the method of simultaneous equations. Thus, by using twelve or fifteen terms of the power series instead of only the first two or three, and by setting up special formulae, detection performance can be calculated for any signal strength and any modulation. The method is applicable to the tube alone, to a circuit containing the tube and external resistances, and may be applied to any similar non‐linear receiving system.

ISSN:0021-8979    

DOI:10.1063/1.1745050

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

A new mathematical theory of wave filters gives the following results: It is possible to realize as constant an image impedance as desired in the transmitting bands. In the new theory there is no mathematical difference in the consideration of proper attenuation or proper image impedance characteristics. In other words, the same attack applies in both cases. All known wave filters as far as they are symmetrical fourterminal networks or equivalent to such networks in series with a transformer, are contained in the filters of the new theory which comprises all possible filters of this kind. The new theory has been carried through practically to find out the most economical filter for any practical purpose. This results in many cases in solving a given practical question already solved by known methods with considerable saving of material. The chief aim of this paper is to show the relation between the new theory and the older design methods due to O. J. Zobel and other members of the Bell Laboratories.

ISSN:0021-8979    

DOI:10.1063/1.1745051

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

An improved circuit for use in supersonic interferometry in gases is described in which regeneration is under control and by the use of which the amplitude of the exciting e.m.f. may be varied between wide limits. Multiple peaks in the plate current maxima are observed, and several causes for such peaks, particularly the use of crystals having ``parasitic'' frequencies, are pointed out.

ISSN:0021-8979    

DOI:10.1063/1.1745052

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

Cobalt crystallizes in the cubic and hexagonal systems. This paper shows by means of x‐ray diffraction analysis, that cobalt electrodeposited from highpH(alkaline) sulphate solutions has a hexagonal structure which changes into a mixture of hexagonal and cubic, as thepHis decreased.

ISSN:0021-8979    

DOI:10.1063/1.1745053

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

It is shown by x‐ray diffraction methods that ``explosive'' antimony is amorphous before exploding and crystalline afterward. It is also shown that the crystal structure of electrodeposited antimony is influenced by the temperature of the plating bath.

ISSN:0021-8979    

DOI:10.1063/1.1745054

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

The theory of cathode sputtering with the advantages and limitations in the application of this process is discussed, followed by a description of the commercial equipment and methods for applying gold electrode surfaces to diaphragms of certain types of microphones. By proper design of the vacuum chamber and the inside parts, a fairly uniform discharge current density and a uniform deposit is obtained. A constant sputtering rate is produced by the use of a bleeder valve which maintains a proper residual pressure. Adherence and continuity are obtained by the use of a special cleaning process. An extensive bibliography on cathode sputtering is included.

ISSN:0021-8979    

DOI:10.1063/1.1745055

出版商:AIP    

年代:1932

数据来源: AIP

摘要:

The electromagnetic equations are put in their most general form and the following criteria for a useful set of equations and sets of units are established: (1) there should be only one set of fundamental equations, (2) there should be two sets of units, one c .g. s. for the physicist and one practical for the engineer, (3) the eight internationally recognized units should be retained in the practical system, (4) the fundamental equations should be symmetrical in form. It is shown that these criteria can be fulfilled in an infinite variety of ways, of which the Heaviside‐Lorentz system of equations provides the simplest. The relations between c. g. s. and practical units employing this system of equations are tabulated.

ISSN:0021-8979    

DOI:10.1063/1.1745056

出版商:AIP    

年代:1932

数据来源: AIP