摘要:

Calculations and experimental technique used in producing a uniform magnetic field with an end‐corrected solenoid are discussed. The field was trimmed to be uniform to 0.01% in an axial region comprising 63% of the solenoid at a maximum field strength of 480 gauss.

ISSN:0034-6748    

DOI:10.1063/1.1717109

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A semi‐automatic recording spectrometer system finds the loci of magnetic field orientations, relative to a single crystal sample, for which an unsplit component occurs in the Zeeman spectrum of chlorine nuclear quadrupole resonances from the sample. The system operates continuously without attention, except for approximately daily resetting, for up to several weeks to obtain the data for crystals with weak spectra. Circuit diagrams are given for the system components, and the analysis of the data is discussed.

ISSN:0034-6748    

DOI:10.1063/1.1717110

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

An injector pulse‐forming network for the 300‐Mev synchrotron at the University of California has been developed which can be adjusted to produce a pulse to match the acceptance energy of the machine at any energy. This device and a method to determine the acceptance energy curve are described here.

ISSN:0034-6748    

DOI:10.1063/1.1717111

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A mechanical spectrograph shutter for exposure times down to 5×10=8sec with a system for synchronization is described and its performance discussed. In contrast to Kerr‐cell shutters most of the incident light is transmitted, which is of considerable importance in extending the range of photographic spectroscopy to studies of very brief transients.

ISSN:0034-6748    

DOI:10.1063/1.1717112

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A general purpose “fast‐slow” multiple coincidence circuit is described. Three independent sets of fast coincidence conditions and three independent sets of slow coincidence conditions, involving up to five input signals, can be imposed simultaneously using a plug board and a set of patch cords. Coincidence pulse timing is accomplished with the aid of a unique discriminator circuit which can be used either to detect an early point on the rise of the input signals or the time of input signal zero transition. The discriminator bias can be varied over a wide range without affecting the circuit recovery time. The ``fast'' coincidence resolving time can be adjusted from 0 to 0.18 &mgr;sec, and signal delays can be adjusted over a 0.3‐&mgr;sec range. The ``slow'' coincidence resolving time is fixed at approximately 2 &mgr;sec. Semiconductor active elements have been used exclusively.

ISSN:0034-6748    

DOI:10.1063/1.1717113

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

By coupling an analog computer to a conventional high‐sensitivity electron spin resonance (ESR) spectrometer, the total absorption of ESR spectra, which is essentially proportional to the total number of resonances present, is obtained automatically with a typical standard error of 8% for uncorrected data or 2% for simply corrected data. Other considerations inherent in the combination of such equipment are also discussed. An experimental check of the linear dependence of first moment of the usual spectrometer output on field modulation is given.

ISSN:0034-6748    

DOI:10.1063/1.1717114

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A relatively simple adiabatic calorimeter has been developed for measuring the thermal properties of 0.5‐g samples of stable liquids or fusible solids over the temperature range of −130° to +200°C. Adiabatic conditions are automatically maintained during a run by means of a control system based on the use of resistance thermometers and a modified commercial electronic thermoregulator. Fifteen determinations on four pure compounds show that the heat of fusion can be determined to an accuracy of about 1%. Because of the simple semi‐automatic operation, the apparatus is particularly suited to the determination of the purity of organic compounds by the calorimetric method.

ISSN:0034-6748    

DOI:10.1063/1.1717115

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Reproducible and constant evaporation rates can be realized when an evaporant is heated by radiation. This article describes a basic source structure with the controlled characteristics necessary for reproducible thin film techniques. Particular attention to the simplicity of design and application has provided an easily constructed practical source.

ISSN:0034-6748    

DOI:10.1063/1.1717116

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Trurnit and Lauer [Rev. Sci. Instr.30, 975 (1959)] have recently described an automatic recording film balance system suitable for automatic recording of many properties of insoluble surface films. The authors have been working with an instrument similar in principle, somewhat less versatile, but very simply constructed by modifying a Cenco hydrophil balance. It is well suited for automatic recording of force‐area curves for monolayers spread on aqueous substrates. Major components include a linear differential transformer, lead screw barrier advance system, and an x‐y recorder. The practicality of the appratus was demonstrated on a stearic acid monolayer spread from benzene on a distilled water substrate. Sensitivity of 0.01 d/cm in spreading pressure and 0.1 A2in molecular co‐area was readily obtained, together with a surface pressure range of 0–60 d/cm.

ISSN:0034-6748    

DOI:10.1063/1.1717117

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

The double resonance technique aims at removing the effect of spin‐spin coupling by the application of a strong rf field at the resonance frequency of the disturbing nucleus in addition to the weak rf field used for observation of the NMR spectrum. A method is described whereby the weak rf field is obtained by a small audio frequency modulation of the magnetic field strength. This method is applicable to chemically nonequivalent groups of hydrogen nuclei to simplify the interpretation of high resolution proton magnetic resonance spectra. Two examples are given.

ISSN:0034-6748    

DOI:10.1063/1.1717118

出版商:AIP    

年代:1960

数据来源: AIP