摘要:

During the decade of the 1950's the number of bachelor's and master's degrees in physics declined sharply during the first half and then increased just as markedly in the last half of the decade, with an especially large increase in the year 1958–59. With the exception of the low year 1949–50, the number of doctorates in physics did not vary significantly during the decade.

ISSN:0031-9228    

DOI:10.1063/1.3057968

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

At the Westinghouse Research Laboratories we have recently re‐examined four questions which scientists have asked many times: (1) What does a corporation expect of a central research and development activity?; (2) Why carry out basic research in industry?; (3) Are scientific objectives and the profit motive compatible?; (4) What support should management provide the research scientist? The answers to these questions are important to us because they are important to our scientists. We have sought, therefore, to ask ourselves these and similar questions as directly as the scientists themselves would put them and then to seek answers in language just as understandable.

ISSN:0031-9228    

DOI:10.1063/1.3057969

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Perhaps a few of you were present at the 1954 Symposium on University Reactors, sponsored by the present august institutions and by the Subcommittee on University Reactors of the National Research Council. If so, you will remember the spirit of the time—university reactors werethething; the one at North Carolina had been started with ceremony and success, and several others were planned, funded, and under design. In the new auditorium at the Oak Ridge National Laboratory, with the support and blessing of the Atomic Energy Commission, enthusiasm was in full flower. In this atmosphere, there appeared a character named Dr. Diddle. Diddle was a fictitious soul—a physics department head who had been given funds for a nuclear machine, the first in his university, and from his conversation there came the chilling suggestion that perhaps a reactor mightnotbe the best choice. Diddle's doubts may have had the effect of a damp blanket upon that conference for a few minutes; but, if so, the fires of enthusiasm quickly rekindled.

ISSN:0031-9228    

DOI:10.1063/1.3057970

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

In 1928, J. B. Johnson showed experimentally that a resistor with no current flowing in it has a measurable electrical noise across its terminals. The signal of the magnitude of a few microvolts is called noise because when made audible through hi‐fi audio amplifier and speaker, it has a high‐pitched hissing quality. Noise from a current‐free metallic resistor is called Johnson noise, or sometimes thermal noise, because Johnson identified the voltage fluctuations across the resistor with thermal agitation of the charge carriers. His classic experiments showed that the mean‐square‐voltage noise signal was directly proportional to the resistance and the absolute temperature in various types of solid as well as in liquid resistors.

ISSN:0031-9228    

DOI:10.1063/1.3057971

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

During recent years there has been a remarkable correlation or explanation of a wide variety of experimental nuclear data in terms of the socalled independent‐particle model (IPM) of the nucleus. This model, which encompasses both the shell model and the optical model, views a nucleon which interacts with the many other nucleons in a complex nucleus as interacting with the nucleus as a whole via an IPM potential. For nucleon‐nuclear interactions the potentials which have been inferred by phenomenologists from a vast amount of data have the general form shown in Fig. 1. Here the vertical scale represents the IPM potential of a nucleon interacting with the nucleus as a whole and the horizontal scale represents the radial distance (r) from the center of the nucleus. The curves shown represent IPM potentials used to represent typical nuclei with mass numbersA = 50,100, 150, 200, and 250. A convenient and frequently used form function for representing nuclear potentials is the Saxon potentialf(r) = {1+exp[(r−R)/d]}−1,whereRrepresents the radial distance to the point at which the potential reduces in magnitude to 0.5 of its central value anddis a parameter which determines the diffuseness or surface thickness of the potential. Experimental data with beams of deuterons, alpha particles, other nuclei, as well as pions andKmesons, all scattered by heavy nuclei, seem to be accounted for quite readily in terms of the optical‐model form of the IPM. The success of the IPM seems so broad that one might be tempted to apply it to a great variety of physical phenomena and even sociological phenomena.

ISSN:0031-9228    

DOI:10.1063/1.3057972

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The American Institute of Physics has undertaken a project on source materials for the history of recent physics in the United States. One part of the project will be to locate materials that document significant work by twentieth‐century physicists, and to take steps toward the preservation and the cataloging of such material. Another part of the project will be to encourage and initiate historical researches by scholars upon these materials. The project promises to be an important step toward greater efforts by the physics community to document the story of recent developments in physics in the United States for the benefit of contemporary historians of science and—even more—for the benefit of historians of the future.

ISSN:0031-9228    

DOI:10.1063/1.3057973

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

More than 500 scientists took part in the Second International Conference on Quantum Electronics, which was held at the Claremont Hotel in Berkeley, Calif., under the sponsorship of the Office of Naval Research and the University of California. Within the three‐day conference period (March 23–25, 1961), some sixty papers were presented on recent progress in masers of various types (especially those involving the higher‐frequency microwave and optical regions), phonon interactions and relaxation processes in solids and gases, narrow‐line optical spectra of solids and gases, optical pumping, and a number of new ideas and accomplishments having to do with the interaction of matter and electromagnetic waves. In addition to those from the United States who attended the meeting, there were delegates from England, France, Germany, Israel, Japan, Switzerland, and the USSR.

ISSN:0031-9228    

DOI:10.1063/1.3057975

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3057976

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3057977

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3057979

出版商:AIP    

年代:1962

数据来源: AIP