摘要:

Perturbation of a simple two particle system is briefly reviewed in one dimension leading to symmetrization of the total system's wave function for the case of identical non-interacting particles. The results of admitting some mutual particle interactions are studied by observing changes in the total system's wave function. For the case of hard-core interactions the effects on the system's symmetry properties are computed.

ISSN:0002-9505    

DOI:10.1119/1.1987909

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

摘要:

In analyzing atomic systems undergoing interactions with external fields that are nearly resonant with two, and only two of the atom's energy levels, one commonly employs a two-level or resonance approximation in which all states of the atom are neglected except for the two in resonance with the field. In this paper, we examine the assumptions necessary to make the transition from a differential equation for the exact polarization of an atomic system to the corresponding equation in the two-level approximation. Only when one includes contributions from states outside the two-level subspace does he find the exact equation reduces to the two-level equation within correctional factors of an intuitive nature.

ISSN:0002-9505    

DOI:10.1119/1.1987910

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

摘要:

A derivation of the conservation laws for electromagnetic fields in vacuum which result from the invariance of Maxwell's equations under the conformal group is given. The arguments presented are easier to follow than those given by Bessel-Hagen in 1921, when the original investigation of these conservation laws was made. It is shown in this paper that four of the fifteen conservation laws can be derived from the remaining eleven. Only one of these eleven remains without physical interpretation. This particular conservation law is of some interest today in high-energy physics.

ISSN:0002-9505    

DOI:10.1119/1.1987911

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

摘要:

A new look at the physical origins of spherical aberrations in axially symmetric electrostatic lenses is offered with the hope of communicating to physics teachers what are the essentials of electron optics that are relevant to students of biology and medicine, who must think critically about the resolution of the electron microscope.

ISSN:0002-9505    

DOI:10.1119/1.1987912

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

摘要:

This paper deals with the subject of laser hazards, laser hazards control, and laser safety practices in the laboratory. Laser hazards, which fall into four categories (radiative, electrical, explosive, and toxic) are described in detail. Following this, the status of federal regulations which seek to define laser hazards control and safety standards is briefly reviewed. The paper concludes with a brief discussion of laser safety goggles and a list of suggestions of laser safety practices intended to assist those who are concerned or involved with the use of lasers in a laboratory environment.

ISSN:0002-9505    

DOI:10.1119/1.1987913

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

摘要:

The importance of including electronics in a single course in electromagnetism for life science students is discussed. A course in which this has been done is described, showing how the concepts traditionally taught in an electromagnetism course can be combined with a study of semiconductor devices to give a course with obvious relevance to the student's future career. We advocate a strong emphasis on practical experience and outline our laboratory program.

ISSN:0002-9505    

DOI:10.1119/1.1987914

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1987915

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1987916

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1987918

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1987919

出版商:American Association of Physics Teachers    

年代:1974

数据来源: AIP