摘要:

During the year 1968 there are major anniversaries of the birth or death of eleven men whose accomplishments and influence have been of importance to the development of physics. They are: David Brewster, Jean Bernard Léon Foucault, Jean Baptiste Joseph Fourier, James Prescott Joule, John LeConte, Robert Andrews Millikan, Gaspard Monge, Wallace Clement Ware Sabine, Arnold Johannes Wilhelm Sommerfeld, John Sealy Edward Townsend, and Robert Williams Wood. Brief accounts of their lives and achievements are given here.

ISSN:0002-9505    

DOI:10.1119/1.1974407

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A description is given of the design, construction, and performance of a Raman source which could be used in a senior laboratory accompanying optics and spectroscopy courses. The apparatus utilizes a single low-pressure mercury arc lamp at one focus of an elliptical housing. Light scattered axially from the Raman sample at the other focus is condensed onto the spectrograph slit via a lens system which also eliminates non-scattered radiation. When used with a Hilger and Watts model D-186 constant deviation spectrograph, a spectrum forCCl4was obtained after an exposure of about two minutes on general purpose spectrographic plates. The classical spring constant is calculated forCS2.

ISSN:0002-9505    

DOI:10.1119/1.1974401

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A method is described whereby the electrical conductivity and Hall coefficient of high-resistivity semiconductors can be measured using a single electrometer for current and voltage measurements. Measurements are made following the L. J. van der Pauw technique with the electrometer switched to perform the necessary functions while maintaining the low side at ground potential. The variation of conductivity and Hall coefficient with temperature can be determined by a point by point method or the data can be recorded on anX-Yrecorder. Conductivities as low as10−10Ω−1·cm−1have been measured.

ISSN:0002-9505    

DOI:10.1119/1.1974402

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The arc spectrum of bismuth has been photographed using the 3.4 m Ebert plane grating spectrograph. The light source used is a commercially available sealed-off hollow cathode discharge. The hyperfine structure of the linesλ = 3596 Åin the seventh order andλ = 4122 Åin the sixth order have been studied. It is pointed out that without using special spectroscopic light sources and high resolution interferometers, the hyperfine structure can be studied in detail with reference to their separations and relative intensities. From the results, this experiment is recommended as suitable for an advanced optics and spectroscopy or quantum physics laboratory.

ISSN:0002-9505    

DOI:10.1119/1.1974403

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A simple recursion formula is introduced for the derivation of the generating function of the canonical transformation in classical mechanics in the form of a power series int, where the transformation relates a variable at the timetwith its initial value given att = 0. A discussion is given of the relationship of this approach to the Hamilton-Jacobi differential equation, with emphasis on the comparison of the formal aspects of classical and quantum mechanics.

ISSN:0002-9505    

DOI:10.1119/1.1974404

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A superregenerative nuclear quadrupole resonance spectrometer designed for use in an advanced undergraduate laboratory is described. The temperature variations of the63Cuand65Curesonances inCu2Oare investigated. The results yield information on the lattice dynamics ofCu2Oand allow a determination of the ratio of the nuclear quadrupole moments of the copper isotopes.

ISSN:0002-9505    

DOI:10.1119/1.1974405

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A unified account is given of the thermodynamic and statistical aspects of magnetic cooling with particular reference to adiabatic demagnetization of a paramagnetic salt. Nuclear cooling and the adiabatic magnetization of antiferromagnets and superconductors are also considered along with the related phenomena of negative temperatures and para-electric cooling.

ISSN:0002-9505    

DOI:10.1119/1.1974406

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The conservation of linear momentum and the coefficient of restitution are used to derive a formula in which the fraction of energy transferred throughnbodies in one-dimensional collisions depends upon the coefficient of restitution, the relative masses of the bodies, and the number of bodies involved. The percent of energy transferred is graphed as a function of the coefficient of restitution and the number of particles which constitute a mechanical impedance-matching-taper transformer between two end particles whose mass ratio is one-hundred. A demonstration device illustrating the impedance match is discussed.

ISSN:0002-9505    

DOI:10.1119/1.1974408

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

This paper describes an experiment using a linear air track, which demonstrates the conservation of energy during a collision between an “electron” and an “atom” capable of being raised to an excited state during the collision. The experiment proves that the minimum energy of the incident “electron” required for excitation is larger than the actual excitation energy.

ISSN:0002-9505    

DOI:10.1119/1.1974409

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The problem of two particles in a common harmonic oscillator potential interacting through harmonic oscillator forces is discussed from the standpoint of the Hartree-Fock approximation and compared with the exact solution.

ISSN:0002-9505    

DOI:10.1119/1.1974410

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP