摘要:

The ionization method is applied to the curved‐crystal spectrograph. The ionization chamber is mounted behind a slit moving in the focal cylinder. Tests on the MoK&agr;1&agr;2doublet indicate better intensity than that obtainable with the usual Bragg spectrometer for a given resolving power. The best line widths are not as narrow as those obtainable with a double crystal spectrometer.

ISSN:0034-6748    

DOI:10.1063/1.1751475

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751476

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751477

出版商:AIP    

年代:1939

数据来源: AIP

摘要:

A description is given of improvements and details of operation of a rubber heat engine of the pendulum type invented by Wiegand. The pendulum is kept in continuous operation by heat energy emitted by a radiant heater and intermittently absorbed by rubber bands. The major features of improvement in the design are essentially (1) increased mechanical stability, (2) decreased size and weight, and (3) considerable simplification of parts.

ISSN:0034-6748    

DOI:10.1063/1.1751478

出版商:AIP    

年代:1939

数据来源: AIP

摘要:

Two voltage regulators are described. The first is satisfactory where there is only a very small current drain; the second will maintain constant voltage output up to the current carrying capacity of the radio tube. For each the change of output voltage with change of input can be made zero. Where extreme constancy is required, the second circuit described is recommended. It approximates closely perfect regulation. The coefficient of voltage change of the output, defined by (1/V0)(∂V0/∂Vi) whereV0is the output voltage andViis the input voltage, is less than 10−7per volt. The regulation is equally as good for surges as for longer random or periodic fluctuations. The circuit also maintains a constant voltage output for varying current drains, the output resistance being about 10 ohms. Currents up to 100 milliamperes at several thousand volts may be drawn with no significant change in the output voltage. The coefficient of drift defined by (1/V0)(∂V0/∂t), wheretis the time, will usually be less than 10−4per hour even under normal laboratory conditions where no special precautions are taken.

ISSN:0034-6748    

DOI:10.1063/1.1751479

出版商:AIP    

年代:1939

数据来源: AIP

摘要:

Two known methods for measuring the internal volume of steel capillaries were compared. The volume obtained from the mass and density of mercury contained was from 3 to 6 percent smaller than that determined by the gas expansion method. The latter is the correct volume to be used for measurements with gases.

ISSN:0034-6748    

DOI:10.1063/1.1751480

出版商:AIP    

年代:1939

数据来源: AIP

摘要:

A large rotor or centrifuge, an armature, and a small iron rod are anchored coaxially one above the other, in the order named, on a small flexible shaft. The shaft passes through a vacuum‐tight oil gland which seals a vacuum‐tight chamber surrounding the large rotor. A direct current which energizes an electromagnet situated vertically above and coaxial with the iron rod is adjusted so that the pull on the iron rod is slightly greater than necessary to support all of the rotors. The extra lift is balanced by a slight thrust against the upper end of the shaft by an oiled bronze stop in the pole piece of the electromagnet. The adjustments are made to maintain a small air gap between the rotating iron rod and the stationary pole piece. The rotors are driven by a piezoelectrically‐controlled a.c. through the field of a single‐phase induction motor which surrounds the armature. Six‐inch centrifuges have been spun to over 1000 r.p.s. at very constant speed.

ISSN:0034-6748    

DOI:10.1063/1.1751481

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751482

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751484

出版商:AIP    

年代:1939

数据来源: AIP