摘要:

An analysis is made of the spectra resulting from the process of internal conversion to measure the inner‐shell binding energy of certain nuclides. Use is made of theK/Lratio of the internal conversion coefficients to predict spin and parity changes in the electromagnetic transitions involved. Such an analysis can quite easily be introduced into an undergraduate nuclear laboratory program.

ISSN:0002-9505    

DOI:10.1119/1.16716

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

Expansions in terms ofL2integrable functions, such as Slater or Gaussian orbitals, or Hermite functions, are usually employed to describe bound states of atomic and molecular systems. A less familiar property of these expansions is that they can accurately reproduce continuum wave functions in selected regions of configuration space, yielding a procedure that is widely used in the calculation of probabilities of predissociation and ionization, as well as of unimolecular and bimolecular reactions. In the present work it is argued that the essentials of this procedure can be introduced with a modicum of theory through an extremely simple example, which lends itself to further numerical experimentation.

ISSN:0002-9505    

DOI:10.1119/1.16688

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

The accuracy of the adiabatic approximation in quantum mechanics is examined by applying it to the forced harmonic oscillator for which the time‐dependent Schrödinger equation can be solved exactly. Nonadiabatic transitions caused by the external force that varies in time is focused on. A peculiar situation is illustrated such that, no matter how rapid and large the variation of the external force may be, all nonadiabatic transitions vanish exactly ast→∞.

ISSN:0002-9505    

DOI:10.1119/1.16689

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

A very simple numerical method for solving boundary problems in electrostatics is presented. The approximation scheme is based on the substitution of a series expansion of the electrostatic potential by a finite sum and a discretization of the boundary where the conditions are given. These boundary conditions may be of the mixed type. In this way the original problem is reduced to the solution of a system of linear equations. As an application of the method proposed, the problem of a hollow cap of a sphere set to a constant potential is treated.

ISSN:0002-9505    

DOI:10.1119/1.16690

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

The study of the Dirac delta potentials in more than one dimension allows the introduction within the framework of elementary quantum mechanics of many of the basic concepts of modern quantum field theory: regularization, renormalization group, asymptotic freedom, dimensional transmutation, triviality, etc. It is also interesting, by itself, as a nonstandard quantum mechanical problem.

ISSN:0002-9505    

DOI:10.1119/1.16691

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

The elastic scattering of strongly interacting particles from a heavy nucleus is considered. For a specific model potential, a closed‐form representation of the differential cross section is constructed within the Born approximation. This expression is used to relate some prominent features of the cross section to the geometry of the target nucleus. Effects arising from the Coulomb interaction are also discussed.

ISSN:0002-9505    

DOI:10.1119/1.16692

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

The force of static friction on a cord wrapped through an angle θ around a rough‐surfaced cylinder increases exponentially with θ. A small tensionT1at one end of the cord, maintaining contact between cord and cylinder, provides the condition for a substantially larger tension, of maximum valueT2=T1 exp(μsθ), at the other end. The validity of this relationship is studied for the kinetic friction case. The suitability of this system for an undergraduate experiment is discussed, together with practical applications—the donkey engine and the capstan—with a digression on sea chanties.

ISSN:0002-9505    

DOI:10.1119/1.16693

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16695

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16696

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16697

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP