ISSN:0002-9505    

DOI:10.1119/1.1974368

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The Robert A. Millikan Lecture Award is made annually to a physicist chosen by a special committee of the American Association of Physics Teachers because of his creative and imaginative contributions to the teaching of physics. The lecturer selected is one whom the Association wishes to honor at the Summer Meeting in the same way that it honors the Oersted Medalist at the time of the Annual Meeting. The award is made possible through the annual support of Prentice-Hall, Inc.; the first award was made in 1964.The recipient of this award for 1968 is Alan Holden, Member of the Technical Staff, Bell Telephone Laboratories.

ISSN:0002-9505    

DOI:10.1119/1.1974369

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The partial wave expansion for a quantum-mechanical plane-wave scattering from a hard sphere is evaluated numerically, and various graphical presentations of the probability density are made.

ISSN:0002-9505    

DOI:10.1119/1.1974370

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

An elementary derivation of the Bethe-Weizsäcker semiempirical nuclear mass formula which is in the spirit of current views of nuclear structure, is given. Lennard-Jones potentials are assumed to act between nucleons. Thus the major interaction betweennn,pp, andnppairs is taken of the form−gsol;r3+hsol;r4, whereris the separation distance between nucleons, andgandhare constants. An additional “symmetry” interaction of the form−s/r3is assumed fornppairs. Summing the potential energy over all nucleon pairs and using the Fermi statistical estimate of the kinetic energy, the Bethe-Weizsäcker semiempirical mass formula is obtained directly. The constants of the mass formula are discussed in relation to theN-Ninteraction and are found to be quite plausible.

ISSN:0002-9505    

DOI:10.1119/1.1974371

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The isospin, spin, and spin-isospin modes of collective nuclear excitation are reviewed in a form suitable for presentation in a graduate-level nuclear physics course. The transition charge and current densities as given by a shell model description of these collective states are compared to those of the hydrodynamical theory. These densities are demonstrated to be identical in form if the individual particle model is based on an oscillator potential and if the usual custom of keeping only the first derivative in a Taylor expansion of the hydrodynamical charge operator is adopted. Only doubly closed-shell nuclei withN = Zare considered.

ISSN:0002-9505    

DOI:10.1119/1.1974372

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

Henri Poincaré was the first to introduce four-vectors, the Lorentz group and its invariants (including the space-time metric), “Poincaré stresses,” as well as making other valuable contributions to relativity theory. We owe to him the names: “Principle of Relativity,” “Lorentz group,” “Lorentz transformation,” and “invariants of the Lorentz group.” It will be shown that his main contributions to relativity were those of a mathematical nature. This has not been sufficiently recognized, although his physical contributions to relativity have been much discussed recently. Frequent misunderstanding of the work of Poincaré and Einstein has resulted in controversy tending to obscure the main achievements of Poincaré. The Poincaré stresses are discussed because of widespread ignorance regarding the theory of classical fundamental charges. The emphasis in this article is on those accomplishments of Poincaré by which he should be better known today. In addition, some misconceptions about the history of relativity and classical electron theory will be corrected.

ISSN:0002-9505    

DOI:10.1119/1.1974373

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

It is observed that the one-dimensional analog of the Slater KDP model provides a simple introduction to the study of strongly interacting systems and phase transitions as well as to recent research on two-dimensional KDP models. Although the first-order phase transition of the one-dimensional Slater model technically disappears when more realistic interaction strengths are taken into account, an anomalously large specific heat remains in the modified one-dimensional model.

ISSN:0002-9505    

DOI:10.1119/1.1974374

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

This note presents the study of the behavior of the real and imaginary parts of the complex refractive index of a homogeneous isotropic plasma. The independent variable is eitherx =thinsp;ν/ωory = (ωp/ω)2while the other quantityy(orx) is considered to be a parameter and held constant. It is shown that both the real and the imaginary parts of the refractive index may possess extrema. They are maxima whenxalone is varied while they may be minima whenyalone is varied. The present investigation supplements the work of Ratcliffe.

ISSN:0002-9505    

DOI:10.1119/1.1974375

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A diagrammatic procedure is described, by which the time dependence of the population of any level in a decay scheme of arbitrary complexity can be prescribed directly in terms of transition probabilities and initial populations, without specifically solving the determining differential equations.

ISSN:0002-9505    

DOI:10.1119/1.1974376

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The motion of a perfectly elastic ball on a regularly corrugated level surface resembles that of an electron in a periodic lattice in that uniform progression across the surface is possible only when the energy of the ball lies within one of a number of discrete regions. These regions correspond to rolling and to even bouncing from ridge to ridge; other simple bouncing motions are found to be unstable, and it is shown that the bands of energy corresponding to more complex stable modes of propagation, if they exist, must be very narrow.

ISSN:0002-9505    

DOI:10.1119/1.1974377

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP