摘要:

Photopolymers play a vital role in this ‘polymer era’ in realizing various processes and devices. Here some of their interesting applications in the fields of nonlinear optics and holography are explained with some examples.

ISSN:0094-243X    

DOI:10.1063/1.48804

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Optical coatings1 are stratified media that encourage interaction amongst many diverse properties, the principal ones being the intrinsic optical properties and optical interference. Optical coatings may range from simple antireflection coatings to dispersion controllers in ultrafast pulse systems, or from solar control coatings to optical data storage media. They may even be used as optical switches. Their principal role may be the modification of the optical properties of a surface or they may be important devices in their own right. Although the properties and applications of coatings are wide ranging nevertheless there are important common features both in the makeup of coatings and in their principles of operation. The design of optical coatings, the topic of this paper, is essentially the control of complicated interference to achieve desired optical effects and it is being helped considerably by new tools, many of which are derived from the current impressive advances in computing power. In spite of the new tools, however, there continue to be very difficult, perhaps intractable, problems. Some of these have been with us for a long time. An obvious question is whether or not the optical coating designer is gradually being made redundant but an inadequacy of completely automatic design methods when coating complexity increases beyond a certain point implies the need for continuing understanding, knowledge, experience, and skill.

ISSN:0094-243X    

DOI:10.1063/1.48757

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The wavelength of a laser diode can be shifted by the injection current of the laser. If such a laser diode is used as a light source of unequal‐path interferometer, the phase shift between two beams can be changed by the injection current. This phenomenon is conveniently employed in phase‐shifting interferometry because no mechanical change is necessary to make a phase shift, and various new techniques have been developed by using this phenomenon. A new technique based on these principles is proposed to measure a plane parallel plate. A method of compensation of error due to the non‐linear change of wavelength is also proposed.

ISSN:0094-243X    

DOI:10.1063/1.48758

出版商:AIP    

年代:1995

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.48759

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

In partnership with the United Nations Educational, Scientific, and Cultural Organization (UNESCO), Iowa State University (ISU) has formed the International Institute of Theoretical and Applied Physics (IITAP). The mission of IITAP is to foster excellence in scientific research and teaching, especially in developing geographical areas, with an emphasis on advanced studies and original research in physics and overlapping disciplines. The Institute is open to qualified scientists of all countries. The Institute provides an open forum for scientific dialogue and furnishes modern facilities for research and collaboration among all participants of its scientific programs. The Institute will form long‐term partnerships with research and teaching institutions in developing countries to help strengthen their infrastructure in science and technology. To achieve its mission, the Institute is working in partnerships with other US research organizations and institutions of learning. Six initial thrust areas and their activities are outlined.

ISSN:0094-243X    

DOI:10.1063/1.48760

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We exhibit chemical composition statistical properties of the HIV1 genetic sequence which are related to the virus variability. Our analysis stems from a nonlinear coupled map lattice modeling of the genetic sequence evolution. We argue that the observed trends are a consequence of the molecular machinery involved in the virus protein translation process. Our study suggests a clue for a therapeutical treatment for AIDS. A conjecture on the role in genetic coding of the nucleic acid composition at the third position within a codon also follows.

ISSN:0094-243X    

DOI:10.1063/1.48761

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Mapping of thermodynamic properties of a fluid into a square‐well (sw) system allows to express those properties in terms of: 1) a universal component in the form of the sw equation of state as a reference, and 2) mean molecular parameters characterizing a species with intermolecular potentialu. The molecular parameters are an energy &egr;, a mean core diameter &sgr;=&sgr;*rm—wherermis the minimum of the potential—and an effective attractive range &lgr;&sgr;: &egr; andrmare scale factors and &sgr;*(&rgr;,T,[u]) and &lgr;(&rgr;,T,[u]) are physically meaningful shape functions associated to the repulsive and attractive parts ofu. Behavior of the shape functions is discussed for a variety of model fluids at low and high densities. Experimental properties of real fluids are used to determine the mean molecular parameters without assuming specific potential models. The approach provides very accurate and compact expressions for the virial coefficients of real and model fluids, as well as for thermodynamic coefficients of real liquids.

ISSN:0094-243X    

DOI:10.1063/1.48762

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A discretized version of the damped Kuramoto‐Sivashinsky (DKS) equation is constructed to provide a simple computational model of spatiotemporal chaos in one‐dimension. The discrete map is used to study the transition from periodic solutions to disordered solutions (i.e., spatiotemporal chaos). The numerical evidence indicates a jump discontinuity at this transition.

ISSN:0094-243X    

DOI:10.1063/1.48763

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Extended Irreversible Thermodynamics, as an extension of Linear Irreversible Thermodynamics has had some success in providing a description to a wide variety of phenomena occurring in non‐equilibrium systems. Nevertheless, its formal structure still poses questions not yet satisfactorily resolved. Here we discuss two of the most important ones namely, the concepts of non‐equilibrium entropy and temperature.

ISSN:0094-243X    

DOI:10.1063/1.48764

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We investigate the effects of anisotropic interfacial tension on the steady state pattern selection in the Saffman‐Taylor problem. Using solvability theory, formulae describing the steady state patterns are derived in closed form, and new states that are found are compared with the isotropic case. Further, dynamical simulation of the moving boundary suggests that the anisotropy is irrelevant for small driving velocities. For sufficiently large driving velocities a new steady‐state width is selected when the anisotropy makes the local interfacial tension a maximum at the finger tip.

ISSN:0094-243X    

DOI:10.1063/1.48765

出版商:AIP    

年代:1995

数据来源: AIP