ISSN:0002-9505    

DOI:10.1119/1.18006

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18007

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18010

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18011

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

A lecture delivered at the annual conference of the American Association of Physics Teachers, Spokane, Washington, 9 August 1995.

ISSN:0002-9505    

DOI:10.1119/1.18012

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

The van der Pauw technique for resistivity and Hall measurements is illustrated on large‐scale models of conductive polyethylene, which can be used to visualize the potential distribution in arbitrarily shaped two‐dimensional samples. The equipotential lines in a square sample and the dependence of measured voltages on the aspect ratio of these samples are studied. We give examples of the use of conformal mapping in two‐dimensional conduction.

ISSN:0002-9505    

DOI:10.1119/1.18013

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

Since 1985 the Colgate University Department of Physics and Astronomy has been reshaping the first term of introductory calculus‐level physics to answer the question: ‘‘Why do we believe in atoms and the properties ascribed to them?’’ This paper describes the new course, its 400‐page text, its ten laboratories, its six computer exercises, and how these work together successfully to serve several purposes: For those students who do not continue on with any more physics, it is a good introduction to physics; for the many students whose quantitative skills need enhancing, it provides a better chance to improve those skills than traditional introductory physics; by its emphasis on wave‐particle duality and mass‐energy equivalence, the course introduces students to important quantum and relativistic ideas that are fundamental to most of what contemporary physicists actually do. We also extract from our reform efforts some lessons useful to anyone undertaking to change introductory physics.

ISSN:0002-9505    

DOI:10.1119/1.18095

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

Since 1986 we have offered courses on special relativity and general relativity in a variety of formats over computer networks nationwide to a mix of high school students, high school teachers, college students, and college professors. Using ideas from many sources, we have evolved a highly structured format that keep students working every day and talking extensively with one another over the conference system. Obligatory student ‘‘Reading Memos’’ bring a flood of comments and complaints essential to evaluation of student progress and revision of the text. We consider possible reasons why these courses from the United States have not worked with participants in Europe, and speculate about possible consequences of future technological developments.

ISSN:0002-9505    

DOI:10.1119/1.18014

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

Intrinsic paramagnetic states are ubiquitous in biological systems, and extrinsic paramagnetic probes are often introduced in studies of biomolecular structure. The measurements of electron paramagnetic resonance and magnetic susceptibility are commonly employed in investigations of biomolecular paramagnetism. How the data obtained from these measurements are used to arrive at electronic structure, and how the electronic structure and its changes relate to biologically functional processes, are the subjects of this review. Emphasis is placed upon the role of magnetic measurements in quantifying the special properties which proteins confer upon iron and copper ions.

ISSN:0002-9505    

DOI:10.1119/1.18015

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

A very simple model of a diatomic molecule—a rigid dumbbell‐flywheel system—is used to illustrate the close relationship between molecular dynamics and gauge fields. It is shown that, under the adiabatic approximation and certain assumptions, even a simple classical analysis yields a Lorentz force in nuclear dynamics due to a magnetic monopole gauge field. This classical treatment, however, fails to explain the origin of the ‘‘magnetic’’ force. An exact quantum mechanical treatment based on relinquishing the Born–Oppenheimer approximation reveals unambiguously both the origin and the nature of the monopole gauge potential, justifies the adiabatic approximation, and yields an expression for the energy eigenvalues. We believe this simple and exactly solvable model is not only suitable as a pedagogical tool for molecular dynamics, but also ideal for communicating some aspects of the physics behind gauge field theories to advanced undergraduates.

ISSN:0002-9505    

DOI:10.1119/1.18016

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP