ISSN:0002-9505    

DOI:10.1119/1.10577

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The AAPT Awards Committee selected Tung Hon Jeong to receive the Robert A. Millikan Lecture Award for 1976. This award, which is given for ’’notable and creative contributions to the teaching of physics,’’ was presented at the annual summer meeting, held at the University of Missouri–Rolla in Rolla, Missouri in June 1976.

ISSN:0002-9505    

DOI:10.1119/1.10578

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

This paper summarizes the results of fourteen separate studies comparing the learning outcomes of a new instructional procedure, the ’’Personalized System of Instruction’’ (PSI), with the learning outcomes of conventional approaches to college teaching. The major conclusion suggested by this summary of research is that, when evaluated by average student performance on course content examinations, PSI has proven superior to the conventional methods with which it has experimentally been compared. The author examines features of PSI courses which probably account for this superiority, and he discusses some of the theoretical and practical implications of research on PSI conducted between 1967 and 1974.

ISSN:0002-9505    

DOI:10.1119/1.10579

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The overwhelming concentration of physics activity in Mexico City, resulting in a ’’brain drain’’ from other parts of the country, has led to a number of efforts designed to decentralize the Mexican educational and research establishments. We evaluate here one such project, established in June 1972 at the University of San Luis Potosí and continuing at present. Begun primarily as a modest research effort, in its present—and most successful—phase, intensive core graduate level courses are given in San Luis Potosí by visiting professors. Although the results of the project have not met our optimistic expectations, a nucleus of dedicated physicists has been formed, and the competence of local teachers has increased.

ISSN:0002-9505    

DOI:10.1119/1.10580

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The purpose of this paper is to discuss two forms in which the time–energy uncertainty relation can appear. One of them concerns the time of preparation of a given state and the other the lifetime of compound systems. Both will be illustrated here through exactly solvable examples. The first one will be the opening and subsequent closing of a shutter on which we have an incident beam of particles. This problem shows a diffraction‐in‐time effect closely connected with the first type of time–energy uncertainty relation. The second will be the decay of a compound state described through a schematicRmatrix formalism. There one can clearly see the transition between the time–energy uncertainty relation as associated with the interval in which the decay process has been in operation, and as associated with the lifetime of the compound state.

ISSN:0002-9505    

DOI:10.1119/1.10581

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

Using simple arguments we show that a photon, when considered as a quantum‐mechanical particle, may be thought of as being attracted to, or repelled from, an atom. A ’’photon Schrödinger equation’’ (PSE) is used to illustrate the common quantum behavior of photons and, e.g., electrons. Using the PSE we relate the attractive or repulsive atom–photon potential to the dielectric constant of a material and show how total internal reflection may be considered as a photon trapped inside a potential well.

ISSN:0002-9505    

DOI:10.1119/1.10582

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

Louis de Broglie’s doctoral thesis developed a concept of waves associated with material particles that was soon incorporated into wave mechanics and later supported by experimental demonstrations. De Broglie’s original development, however, relied on an incorrect identification of two quite different relations: the relation between the velocity of a particle and the relation between the group velocity of a wave packet and the velocity of individual waves in the packet. A clarification of this difference and its historial significance is followed by a tentative account of the reasons why de Broglie’s well‐known formula proved successful, though the theory supporting it rested on a conceptual confusion. Finally, this development and clarification are related to some of the difficulties involved in the attempts top fashion a coherent interpretation of quantum theory.

ISSN:0002-9505    

DOI:10.1119/1.10583

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The phase space of a light quantum in a given volume is subdivided into ’’cells’’ of magnitudeh3. The number of possible distributions of the light quanta of a macroscopically defined radiation over these cells gives the entropy and with it all thermodynamic properties of the radiation.

ISSN:0002-9505    

DOI:10.1119/1.10584

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The usual textbook discussions of the velocity and spreading of a wave packet are based on special cases and approximations which have a limited range of validity. In this paper more general relations are obtained by considering the time dependence of the moments of a wave packet. Both a packet of real sinusoidal plane waves (a real pulse, e.g., sound) and a packet of complex exponential plane waves (e.g., the quantum‐mechanical wave function of a free particle) are considered. The results are similar if the real wave packet contains no standing wave components. It is shown that the centroid of a wave packet moves at a constant velocity which is a weighted average of the group velocity. The spreading of the wave packet depends on the product of the variance of the group velocity and the square of the time interval before or after the time of minimum packet width. The packet moves and spreads like a collection of particles in free flight, in which the velocities of the particles are the group velocities of the wave components of the packet.

ISSN:0002-9505    

DOI:10.1119/1.10201

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

In quantum mechanics of one dimension it is shown for potentials which become infinite at a point but are continuous elsewhere, that the singularity acts as an impenetrable barrier if the potential is not integrable up to the singularity, but if the potential is integrable the behavior is not essentially different from that of a potential which does not become infinite.

ISSN:0002-9505    

DOI:10.1119/1.10585

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP