ISSN:0031-9228    

DOI:10.1063/1.3068996

出版商:AIP    

年代:1975

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3068998

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Although the electron distribution at the Fermi surface of a metal has long been considered to be well understood, some anomalies of electronic behavior such as magnetoresistivity have hinted that this understanding was not complete. In 1968 Albert W. Overhauser (Purdue University) proposed a model of a Fermi‐surface instability that he called “charge density waves.”1However, the validity of charge density wave theory has only now been established by the experimental observation of periodic structural distortions—unique consequences of this type of instability.

ISSN:0031-9228    

DOI:10.1063/1.3069000

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Alcator—the high‐field toroidal plasma experiment at MIT—has achieved very successful operating conditions since last summer. Its plasma density is the highest of any Tokamak‐like plasma‐containment device, and its Lawson number (product of density and containment time) is competitive for the high ion temperatures at which it runs (see box). Several unique features of this device are its high current density and the wide ranges of such parameters as density and plasma current. Alcator's staff is all the more pleased because the project had initially been making a slow start.

ISSN:0031-9228    

DOI:10.1063/1.3069001

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Following the tradition of past farewell messages, I will comment on the general health of physics; I also want to report, however, on a singular development that occurred during my term in office. This was the discovery of the new particles, an event that has generated a 20‐year high in the level of excitement among high‐energy physicists.

ISSN:0031-9228    

DOI:10.1063/1.3069002

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

We take it pretty much for granted that the whole visible world of matter and radiation can be explained, if not in fact at least in principle, in terms of the interactions of a handful of so‐called “elementary particles”: the electron; the proton; the neutron; the quantum of light, the photon; the quantum of gravitational radiation, the graviton, and perhaps also the neutrino. We would like to know why these particles have the properties they have, and therefore why the world is the way it is. Or, if you do not believe that scientists should ask “why,” you can restate the question in this form: What we want to know is the set of simple principles from which the properties of these particles, and hence everything else, can be deduced.

ISSN:0031-9228    

DOI:10.1063/1.3069003

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

One of the great barriers to improving our understanding of the molecular basis of life is that we do not yet have any way of examining individual macromolecules in living tissue. The progress made so far in unravelling thestructuresof biological macromolecules is based on painstaking chemical and x‐ray crystallographic analyses of pure, crystalline samples of a given macromolecule.1This situation could, however, be completely revolutionized if a source of coherent x rays were available. Although, as we shall show below, the realizaton of this goal is beset with difficulties, experiments aimed towards its accomplishments are under way, as shown in figure 1.

ISSN:0031-9228    

DOI:10.1063/1.3069004

出版商:AIP    

年代:1975

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3069005

出版商:AIP    

年代:1975

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3069006

出版商:AIP    

年代:1975

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3069007

出版商:AIP    

年代:1975

数据来源: AIP