ISSN:0031-9228    

DOI:10.1063/1.2916174

出版商:AIP    

年代:1984

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2916132

出版商:AIP    

年代:1984

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2916145

出版商:AIP    

年代:1984

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2916152

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The first high‐energy superconducting synchrotron in the world, the Tevatron, at Fermilab, accelerated protons to 512 GeV last July. By the time of the 12th International Conference on High‐Energy Accelerators held at Fermilab in August, the Tevatron had reached 700 GeV. Since October it has been used for fixed‐target experiments at 400 GeV. This month Fermilab plans to raise the energy to 750 GeV or so and then run experiments at that energy until July. During the summer, the lab plans to repair marginal magnets and director Leon Lederman hopes the Tevatron will by November indeed be worthy of its name, accelerating protons close to 1000 GeV or 1 TeV. Meanwhile, an antiproton source is being constructed; in 1986 the lab expects to have app¯collider ready for experiments with as much as 1 TeV in each beam.

ISSN:0031-9228    

DOI:10.1063/1.2916154

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Because the binding energies of nuclei are very much smaller than their rest masses, one would not have expected relativistic effects to play a significant role in nuclear structure or nuclear scattering at modest energies. Thus the nonrelativistic Schro¨dinger equation has until recently been the basis for almost all calculations in traditional nuclear physics. But in the past three years, the coming together of precise new data and novel theoretical approaches has made it appear that a fully relativistic treatment is indispensable for the understanding of nuclear phenomena even at low energies.

ISSN:0031-9228    

DOI:10.1063/1.2916155

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

There is a temperamental difference among thinkers that has produced a spectrum of attitudes among them, in all realms of thought, throughout the history of ideas. This difference is the preference, in the one case, for the concrete over the abstract, and in the other for the abstract over the concrete. In science, this temperamental difference distinguishes experimentalists and theorists; in mathematics it distinguishes applied and pure mathematicians; and in philosophy it distinguishes empiricists and rationalists. Thus experimentalists are concerned with concrete apparatus in the laboratory, or concrete specimens in the field, while the nearest that theorists get to experimenting is the “thought experiment,” which cannot be performed in any laboratory. Similarly, although all mathematics is abstract, applied mathematics is less so than pure mathematics; applied mathematicians are concerned with mathematics that relates to the concrete world around them, while extreme pure mathematicians consider such concrete application unimportant at best and an adulteration of mathematics at worst.

ISSN:0031-9228    

DOI:10.1063/1.2916156

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Fifty years ago the periodic table of chemical elements appeared to be complete. Most of the gaps left in the table by Dmitri Mendeleev in 1869 had been filled in, and it appeared that with elements 43, 61, 85, and 87, the periodic table of 92 elements—hydrogen to uranium—would be fully realized.

ISSN:0031-9228    

DOI:10.1063/1.2916157

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Recent progress in novel techniques for generating high‐power coherent radiation promises to make available sources with a variety of new and exciting applications. Interestingly, the new techniques have more in common with those used in the earliest sources of coherent radiation—the various microwave generators—than with those used in the more recent optical lasers. Development of new sources based on these techniques is proceeding rapidly at research centers around the world, because the new sources have a great potential for extending the currently available range of wavelengths and levels of power, while maintaining high operating efficiencies. The areas of application that stand to benefit include spectroscopy, advanced accelerators, short‐wavelength radar, and plasma heating in fusion reactors.

ISSN:0031-9228    

DOI:10.1063/1.2916158

出版商:AIP    

年代:1984

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2916159

出版商:AIP    

年代:1984

数据来源: AIP