ISSN:0031-9228    

DOI:10.1063/1.2808238

出版商:AIP    

年代:1995

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2808239

出版商:AIP    

年代:1995

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2808241

出版商:AIP    

年代:1995

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2808243

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

How much spin can a nucleus take before centrifugal force pulls it apart? A surprising answer is proffered by one of the first physics results from the Gammasphere facility at the Lawrence Berkeley National Laboratory. Gammasphere is the first of a new generation of nuclear‐physics photon detector arrays. In June the Berkeley, Oak Ridge, Washington University collaboration at Gammasphere published evidence that gadolinium‐147 nuclei might be reaching angular momenta as high as 90ħ without succumbing to fission. “That's embarrassingly high,” says collaboration leader Demetrios Sarantites, “because the theory says that the barrier against fission should vanish at around 80ħ.”

ISSN:0031-9228    

DOI:10.1063/1.2808244

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Since the 1986 discovery of high‐temperature superconductors, researchers have been struggling to understand the nature of the magnetic flux lines that thread through these copper‐oxide materials when the field is above a few tens of gauss. the flux lines take the form of vortices, swirling supercurrents that confine the magnetic field to a cylindrical region around a quiescent center. Understanding them is more than an academic exercise: Motion of the vortices, when pushed by a high enough current, introduces resistivity and limits the long‐sought high‐field applications. (SeePHYSICS TODAY, October 1992, page 17.

ISSN:0031-9228    

DOI:10.1063/1.2808245

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

One century ago this month, highenergy electromagnetic radiation—the “X” or “unknown” ray—was discovered by Wilhelm Conrad Rontgen in his basement laboratory. Few other scientific discoveries were as immediately sensational. From hospitals to airports, in physics and biology labs, in the fabrication of nanostructures for electronics and machinery, x rays have come to permeate the modern world. In this special issue we cannot look at the full history and extent of research using x rays. Rather, we have chosen to take a few snapshots of research then and now.

ISSN:0031-9228    

DOI:10.1063/1.881455

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

On Friday evening, 8 November 1895, Wilhelm Conrad Ro¨ntgen, a 50‐year‐old professor of physics and recently elected rector of the Julius Maximilian University of Wu¨rzburg, Germany, was unusually late for dinner. And when he did arrive at the family living quarters above his laboratory in the Physical Institute, he did not speak, ate little and then left abruptly to return to the experiments that had so disturbed him that afternoon.

ISSN:0031-9228    

DOI:10.1063/1.881456

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Since their discovery by Wilhelm Conard Ro¨ntgen, X rays have played a significant role in our lives: they make the unseen in our bodies visible; they enhance our security in air travel; they make possible nondestructive testing of a wide variety of materials. And through x‐ray diffraction and spectroscopy they make it possible to probe the order of matter at the atomic level.

ISSN:0031-9228    

DOI:10.1063/1.881457

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Xrays have had a profound impact in advancing the field of biology, and the pace of fundamental discovery is still accelerating. Through the awesome powers of recombinant DNA technology and synchrotron radiation, as combined in modern‐day x‐ray crystallography, ever‐more‐complicated molecules and assemblages are being worked out in atomic detail. The insights into biological processes derived from these studies are transforming cell and molecular biology.

ISSN:0031-9228    

DOI:10.1063/1.881481

出版商:AIP    

年代:1995

数据来源: AIP