ISSN:0031-9228    

DOI:10.1063/1.2807967

出版商:AIP    

年代:1995

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2807968

出版商:AIP    

年代:1995

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2807969

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Our bodies contain myriad motors to produce mechanical work. We're only too aware of the muscles that propel our limbs or pump our hearts; less noticed are the minuscule molecular motors at the cellular level that accomplish such chores as transporting organelles. All these actions involve motor proteins, enzymes that convert the chemical energy stored in the molecule adenosine triphosphate—known as ATP—into mechanical energy. Exactly how they channel the energy into rectified motion remains a compelling mystery.

ISSN:0031-9228    

DOI:10.1063/1.2807970

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

There may still be some who doubt that the missing‐solar‐neutrino problem is real. But an impressive experiment with a radioactive solar surrogate recently completed at the Gallex solar neutrino detector in Italy makes it difficult to sustain such skepsis.’ The new experiment supports the reports over the last several years that Gallex and Russia's SAGE, the other large gallium detector, see only about 60&percent; of the solar neutrino signal confidently predicted by astro‐physical models. (SeePHYSICS TODAY, August 1992, page 17.) Thus it does much to bring the observational features of the solar neutrino puzzle into clearer focus.

ISSN:0031-9228    

DOI:10.1063/1.2807971

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Horseradish is so potent that it clears clogged sinuses, tickles taste‐buds when dabbed on gefilte fish or roast beef… and now, it can clean up industrial wastewater. Jean‐Mare Bol‐lag, codirector of Penn State's Center for Bioremediation and Detoxification, and Jerzy Dec, a research associate there, report that minced horseradish root can clean wastewater containing phenols a lot more cheaply than other chemical and physical treatments.

ISSN:0031-9228    

DOI:10.1063/1.2807972

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Magnetism abounds with dichotomies: It was known to the ancients and yet is the focus of exciting new research; its manifestations are apparent to every schoolchild yet its origins are rooted deep in quantum mechanics and relativity; its applications underlie huge industries yet its understanding—even in iron—is still incomplete.

ISSN:0031-9228    

DOI:10.1063/1.881446

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Mention magnetics and an image arises of musty physics labs peopled by old codgers with iron filings under their fingernails—good science, this, but not the stuff from which career dreams are spun. Yes, you say, but what about the giant magnetic recording industry—it's still healthy, isn't it? Not according to some. The popular press has made statements about magnetic recording being a technology that has reached its maturity and has limited growth potential. Aficionados of semiconductor memory even advised a few years ago that memory cards based on semiconductor technology would become price competitive with magnetic hard‐disk drives by 1995. This prediction has fallen short by two orders of magnitude.

ISSN:0031-9228    

DOI:10.1063/1.881482

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

With the miniaturization of magnetic technologies, the need to understand magnetization on length scales below a micron is becoming increasingly important. This booming interest in micro magnetics has fueled a renaissance in both micro‐magnetic modeling and measurement techniques. Conversely, the codevelop‐ment of modeling and imaging has made possible recent advances in this critical area of magnetism. On the modeling side, the rapid development of high‐speed computing has had a tremendous impact on micromagnetics simulations. On the measurement side, a number of microscopies have been developed for imaging on a length scale of tens of nanometers. Figure 1 shows an image of rows of bits in a magneto‐optical medium. The bits were both written and imaged using a magnetic force microscope. Results on this length scale provide information that can be used in models and also challenge models’ predictive capabilities. The image on the cover of this issue shows naturally occurring domain patterns in a single‐crystal ferrite, a system that exhibits extremely complex magnetic stmctures.

ISSN:0031-9228    

DOI:10.1063/1.881447

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

For many years physicists thought small structures would be nearly ideal systems in which to explore and manipulate magnetic interactions. On a small enough length scale the interactions between individual atomic spins cause their magnetic moments to align in the ordered pattern of asingle domain, without the complication of domain walls separating regions of varying orientation. For particle sizes at or below that of a single domain, many theoretical models of dynamical behavior predict simple, stable magnets with controllable classical properties. However, as with advances in semiconductor physics, the process of miniaturizing magnetic materials has unexpectedly revealed fascinating new classical and quantum mechanical phenomena. Even the simplest magnetic system, the isolated single‐domain particle, exhibits a wealth of exotic behavior that pushes us to the limits of our present understanding of the fundamentals of magnetism.

ISSN:0031-9228    

DOI:10.1063/1.881448

出版商:AIP    

年代:1995

数据来源: AIP