ISSN:0031-9228    

DOI:10.1063/1.2995655

出版商:AIP    

年代:1979

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2995609

出版商:AIP    

年代:1979

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2995610

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Although many technically advanced nations are attempting to develop laser isotope separation of uranium, detailed information has always been difficult to obtain. Much of the work is classified because of its potential weapons applications; still other work is considered “company confidential” by the industrial firms involved.

ISSN:0031-9228    

DOI:10.1063/1.2995611

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Lasers whose operating frequencies are not determined by energy levels in atoms or molecules have long been a goal of researchers in the field. Stimulated scattering by free electrons passing through spatially varying magnetic fields promises to meet that goal. Two years ago, a group at Stanford reported laser action from stimulated bremsstrahlung, and a collaborative effort of the Columbia University Plasma Lab and the Naval Research Lab has produced a laser based on stimulated Raman scattering by free electrons. These results have encouraged many other laboratories to investigate the construction and potential uses of free‐electron lasers. Active research is now going on at Bell Labs, Los Alamos, The University of Trento, Frascati, Brookhaven, and the Lawrence Livermore Labs, among others. Much of the excitement is due to these lasers' promise of exceedingly high power levels at a low enough cost to make them useful suppliers of industrial process energy.

ISSN:0031-9228    

DOI:10.1063/1.2995612

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

The second orbiting High Energy Astronomy Observatory started its normal operations on 7 January. It has already produced more than a thousand x‐ray images, many of them spectacular pictures of supernova remnants, quasars, galaxies, clusters of galaxies, stars and clusters of stars. It has also produced a number of puzzles, most notably for theories of pulsar formation.

ISSN:0031-9228    

DOI:10.1063/1.2995613

出版商:AIP    

年代:1979

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2995615

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

The topic to which I have been asked to address myself is a difficult one, if one is to avoid the trivial and the banal. Besides, my knowledge and my experience, such as they are, compel me to limit myself, entirely, to the theoretical aspects of the physical sciences—limitations, most serious. I must, therefore, begin by asking for your patience and your forbearance.

ISSN:0031-9228    

DOI:10.1063/1.2995616

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

In every scientific discipline, attention has begun to turn toward the serious shortage of energy in the world as scientists ask themselves, “What can we do about it?” There is certainly no doubt that the problem exists, that it is growing more serious with time, and that it is not going to be solved easily and quickly.

ISSN:0031-9228    

DOI:10.1063/1.2995617

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Webster's dictionary definespanaceaas a “remedy for all ills or difficulties; a cure‐all.” A pseudopotential is an approximation to the real potential an electron feels in a solid. In what sense can it be called a cure‐all? What are the ills it cures, the difficulties it overcomes or the problems it solves? And how does it help solve problems? Our object here will be to supply some answers to these questions and to describe the growing influence of theories involving pseudopotentials on solid state or condensed matter physics.

ISSN:0031-9228    

DOI:10.1063/1.2995618

出版商:AIP    

年代:1979

数据来源: AIP