摘要:

When the State Department's Norman Neureiter showed up at a recent Capitol Hill reception for the US Physics Olympiad team, he did what he has become adept at doing during his past two years in Washington: He saw the science‐oriented gathering as a recruiting opportunity and worked the room. Neureiter congratulated the high‐school physics students for their achievements, and then urged them to consider the State Department as a career option. As he left for his next event, Neureiter made sure there was a stack of his recruitment brochures on the table just outside the door.

ISSN:0031-9228    

DOI:10.1063/1.1603070

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

In early April, on his first full day on the job as the undersecretary for science and technology at the new Department of Homeland Security, Charles McQueary was on Capitol Hill testifying before both House and Senate committees on how he would spend $803 million in R&D money. A couple of weeks later he was back on the hill, detailing the programs being developed for a DHS cybersecurity center. In between, he hired staff and dealt with a host of headaches as he worked to create his portion of the massive new government agency.

ISSN:0031-9228    

DOI:10.1063/1.1603071

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Having apparently outwaited its opponents, the research reactor near Munich in the southern German state of Bavaria is set to turn on late this summer and could be running at full power within a year.

ISSN:0031-9228    

DOI:10.1063/1.1603072

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Since the attacks on the World Trade Center and the Pentagon on September 11th, the fraction of foreigners among incoming physics graduate students in the US has taken a dive, according to a recent report by the American Institute of Physics.

ISSN:0031-9228    

DOI:10.1063/1.1603074

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1603076

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

For nearly a century, physicians have routinely taken x‐ray pictures of broken bones or wounds that contain foreign solid materials. So powerful is this diagnostic tool that not to employ it would seem almost medieval. Thus it comes as something of a surprise to recognize that, although there were numerous small‐scale medical applications almost immediately after Wilhelm Conrad Ro¨ntgen's discovery of x rays at the end of 1895, it took the carnage of World War I, two decades later, to make such radiography widespread.

ISSN:0031-9228    

DOI:10.1063/1.1603078

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Consider almost any metric for the performance or cost‐effectiveness of information technology, and you will find exponentially compounding rates of improvement that extend over years and decades. For example, the silicon field‐effect transistor—the ubiquitous logical switch that performs nearly all of today's information processing—has a wonderful attribute. Properly scaled to smaller dimensions, it uses less power and switches faster. And the smaller the transistor, the more of them that can be fabricated on a given area of Si substrate. Because the processes used to fabricate one transistor can be implemented in parallel to fabricate many transistors, the cost per transistor tends to decline as transistors shrink. True, the manufacturing control of ever smaller dimensions and tighter tolerances requires new and expensive equipment and factories, but the industry has so far successfully amortized those costs over the expanding revenue base enabled by ever cheaper IT products, including cameras, cell phones, televisions, and automobiles. For decades now, the cost of a finished Si chip has remained roughly constant, while the number of circuits on that chip has risen exponentially and the cost of information processing has plummeted.

ISSN:0031-9228    

DOI:10.1063/1.1603079

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

As with any other quantum particle, an electron exhibits wavelike and particlelike characteristics. Which aspect predominates in a solid depends on how an electron interacts with its neighbors. According to the Bloch theorem, for instance, an electron placed in a periodic lattice behaves like an extended plane wave. However, when the number of free electrons in a solid becomes comparable to the number of the constituent atoms and the mutual electron–electron interaction becomes strong, electrons may lose their mobility.

ISSN:0031-9228    

DOI:10.1063/1.1603080

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1603081

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1603083

出版商:AIP    

年代:1903

数据来源: AIP