ISSN:0031-9228    

DOI:10.1063/1.2408553

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1768652

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1768653

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1768658

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1768662

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Since 1999, a collaboration led by Carl Collins (University of Texas at Dallas) has been reporting evidence for the x‐ray induced release of energy stored in an unusually long‐lived nuclear isomer of hafnium‐178. Collins's claims have aroused a public debate whose acrimony reflects issues that go far beyond the interesting but normally staid physics of nuclear isomers.

ISSN:0031-9228    

DOI:10.1063/1.1768663

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

In the Amazon Basin, at the beginning of each dry season in May, farmers start felling trees and clearing undergrowth. The damp vegetation dries out on the ground for a few months. Then, before the rains resume, the farmers set the vegetation on fire. Most of the burning occurs on vast estates. Areas kilometers across are cleared to make way for agriculture. Figure 1 shows one example from the state of Rondonia in western Brazil.

ISSN:0031-9228    

DOI:10.1063/1.1768664

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Small things are quantum and big things are classical. But where is the boundary between the two regimes and what happens there? Once the preserve ofgedankenexperiments, such questions are increasingly tackled in the lab. Markus Arndt, Anton Zeilinger, and their colleagues at the University of Vienna explore the quantum‐classical boundary by subjecting ever larger molecules to matter interferometry. Their latest experiment, on hotC70buckyballs, supports the emerging consensus that an object's interaction with the environment, rather than its mere size or even its complexity, dictates its classicality.

ISSN:0031-9228    

DOI:10.1063/1.1768665

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The federal government has eased restrictions on editing manuscripts from countries under US trade embargoes, but some publishers remain wary that the narrowness of the 2 April ruling leaves them vulnerable to improper regulation and prosecution.

ISSN:0031-9228    

DOI:10.1063/1.1768666

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

“Wrong and misleading” is how Office of Science and Technology Policy Director John Marburger described a recent Union of Concerned Scientists report criticizing the scientific integrity of the Bush administration. In a detailed 20‐page response to Congress and an accompanying summary released to the public on 2 April, the administration refuted point by point the UCS's claims (see http://www.ostp.gov). “I hope this response will correct errors, distortions, and misunderstandings in the Union of Concerned Scientists' document,” he said. “The bottom line is that we have a strong and healthy science enterprise in this country of which I am proud to be a part.”

ISSN:0031-9228    

DOI:10.1063/1.1768667

出版商:AIP    

年代:1904

数据来源: AIP