摘要:

We report experimental results on microwave second harmonic emission in different types of conventional and high-Tcsuperconductors in the critical state. We show that the peculiarities of the second harmonic signal strongly depend on the type of superconductors. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303313

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

We report an electron spin resonance study of the defects induced by &ggr; irradiation in silica. By comparing various materials and by studying the defect growth as a function of the accumulated &ggr; dose, interesting hints are found on the defect origin. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303314

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Noise-induced nonequilibrium phenomena in nonlinear systems have recently attracted a great deal of attention in a variety of contexts. Noise can induce a number of interesting phenomena in periodically driven nonlinear dynamical systems, such as stochastic resonance (SR) and noise-enhanced stability (NES). We report here some new results concerning these noise-induced effects. Specifically: (i) the investigation of the SR phenomenon for a bistable system described by a piece-wise linear potential with arbitrary height and width: (ii) the analysis of noise enhanced stability phenomenon in a piecewise linear potential in adiabatic approximation. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303315

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Spectrophotometry and photoluminescence (PL) are used to investigate the optical properties and photodegradation of thin films of pyrromethene 580 dispersed in polycarbonate (PC). The films spin-coated on glass act as asymmetric planar waveguides and excited with blue light yield a linearly polarized emission whose color changes according to the film thickness. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303316

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

A new painless technique, able to introduce drugs into the body deeply and locally, and the related equipment are presented here. This technique uses electricity for transport of the drugs, which are contained in an iced piece of water mixture that constitutes the active electrode of the dedicated equipment, which generates oscillating currents. It is explained why the association of thermal and electrical stimulation of the skin allows to overcome the disadvantages of the standard iontophoresis. Some clinical interesting results are presented. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303317

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

In this work we report on the correlation between the structural properties, i.e., crystalline/amorphous phase ratio and grain size, and the electrical transport properties of hydrogenated silicon thin films. The samples were deposited by means of pulsed laser ablation of a high purity silicon target in presence of hydrogen gas. Infrared spectroscopy measurements showed a monohydride preferential incorporation at the lower hydrogen pressures. The Raman spectroscopy studies of the TO phonon line suggest that crystallinity and hydrogenation of the films, deposited at room temperature, can be properly adjusted as a function of the deposition parameters. The temperature dependence of both the dark and the photo electrical conductivity shows a thermally activated behavior, which is strictly related to the silicon microstructure and to the hydrogen content and bonding configuration. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303318

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Analysis of low temperature specific heat data (1.5 K–25 K) in two glasses of theAgI-Ag2O-B2O3system reveals that the temperature dependencies ofCpare in qualitative agreement with the predictions of the Soft Potential Model. It has been also found that a decreasing connectivity of the network enhances the deviations ofCpfrom aT3behavior. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303319

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Electron Spin Resonance dosimetry is a useful system for measuring absorbed dose in radiotherapy. This work describes the results obtained at the University of Palermo regarding an experimental study aimed to optimize the properties of alanine based dosimeters and to analyze other materials, that could be alternatives to alanine. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303320

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

A glow curve analysis has been carried out to study the response of some LiF dosimeters when irradiated by radiations with different LET. The aim of the study was to have a better understanding of the role of material characteristics in determining their glow curve response when irradiated with60Cogamma rays and proton beams. Glow curves for TLD-100 and GR-200 LiF dosimeters have been analyzed and deconvolution of the peak structure has been performed within the frame of first order kinetics. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303321

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

We show photoelectron energy spectra of a negative ion irradiated simultaneously by a weak, photodetaching, electromagnetic field of frequency&ohgr;H1and an intense low-frequency bichromatic field (LF) when the frequencies&ohgr;L1and&ohgr;L2of its components are commensurate. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303322

出版商:AIP    

年代:1900

数据来源: AIP