ISSN:0031-9228    

DOI:10.1063/1.2409947

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1564328

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1564329

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1564331

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2409948

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Suppose you wanted to trap DNA near a surface. Dissolved DNA is charged, so an electrical method might come to mind. Or, applying osmosis, you might try a semipermeable membrane. Heat, though, would probably be at the bottom of your list of exploitable physics. Thermal processes, such as convection in a cup of hot tea, tend to mix things up, not concentrate them. Worse, DNA starts to fall apart at a modest 80°C.

ISSN:0031-9228    

DOI:10.1063/1.1564333

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Earth is by no means a perfectly smooth sphere, but a rather bumpy, oblate ball of mass. The nonuniform mass distribution gives rise to variations in Earth's gravitational pull. Although these variations have been measured over many years, the data have come from diverse sources having uneven quality and incomplete geographical coverage. Today's geophysicists want to know more accurately not only what the gravity field is at each point on Earth, but how it is changing with time. Such changes may reflect, for example, charge and depletion of continental aquifers, melting of land‐based glaciers, or changes in ocean currents.

ISSN:0031-9228    

DOI:10.1063/1.1564334

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Sitting 25 thousand light‐years from the great mass concentration at the core of the Milky Way, the Solar System takes 230 million years to complete an orbit about the Galactic center. The prevailing opinion among astrophysicists is that a supermassive black hole, some 3 million times heavier than the Sun, lurks at the heart of this mass concentration about which the Galaxy wheels.

ISSN:0031-9228    

DOI:10.1063/1.1564335

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A day after his resignation as the director of Los Alamos National Laboratory took effect, physicist John Browne was back in the place he'd been five years earlier—the Los Alamos Neutron Science Center. The laboratory's particle accelerator is housed there and Browne, who ran the center before becoming LANL director, was working out plans to “reengage in some of the work I did over 20 years ago in looking at nuclear reactions on nuclei of interest to nuclear astrophysics and nuclear weapons physics.”

ISSN:0031-9228    

DOI:10.1063/1.1564336

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Ten days before the events of 11 September 2001, Stephen Younger arrived in Washington, DC, to replace Jay Davis as the director of the Defense Threat Reduction Agency. DTRA, at Fort Belvoir, Virginia, is part of the Department of Defense and serves as the US hub for developing strategies against weapons of mass destruction. “I wasn't surprised to be offered the job, because the administration was very kind in discussions of how I might be able to come to Washington,” says Younger, who was previously the senior associate director in charge of the stockpile stewardship program at Los Alamos National Laboratory in New Mexico. “We talked about several types of positions, and, after some discussion, this was the one that seemed the best fit.”

ISSN:0031-9228    

DOI:10.1063/1.1564337

出版商:AIP    

年代:1903

数据来源: AIP