摘要:

This paper deals with the enmicrocapsulation of cholesteric liquid crystals by the colloid coaversation process. This incident light reflection study reveals that the encapsulated liquid crystal films sustain highly sensitive and precise temperature gradients with responding abilities determined by their iridescent coloration.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677154

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A time domain technique for the identification of unknown parameters in the nonlinear system of some given structures is presented. The nonlinearities considered in this paper are in the forms of saturation, deadzone and backlash. The steps of the identification process are first to set the initial or guessed system parameters in a learning model, then apply the recorded input signal of the actual system to the mathematical learning model. By comparing the output errors between the model's and the system's responses, an optimization algorithm can be applied to search for the true parameters of the nonlinear system in order to meet a least mean square error criterion. The computer simulations have demonstrated the feasibility of this numerical technique.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677155

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The electrically calibrated pyroelectric radiometer (ECPR) has been constructed. The system is composed of a nichrome‐film‐coated LiTaO3pyroelectric detector, signal conditioning circuits, a heating circuit, a chopper system, and a microprocessor for power computation and synchronization as well as power display. It has been tested and compared with a commercial optical power meter with good consistence. Design considerations of the detector are discussed.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677156

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Two types of GaAs/AIGaAs laser arrays, each consisting of five emitters and suitable for high power operations, have been fabricated and tested. They are easily fabricated, have high yield and deliver high power. The first array structure was fabricated using proton implantation to define the active lasing channels. Damage introduced by proton bombardment provides both electrical and optical confinement for the lasing channels. We have investigated the effect of heat treatment on the performance of these lasers and have found that the heat treated samples had a lower threshold current and higher quantum efficiency. For 400μm long devices, with uncoated facets, we have measured a threshold current of 200 mA and a peak power of 231 mW/facet. The highest external quantum efficiency is 60%. We have also fabricated laser arrays with a simple, self‐aligned, index guided ridge waveguide structures. We have obtain a pulsed output power of up to 551 mW/facet with a quantum efficiency of 37.4%. The typical threshold current is 370 mA.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677157

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A simple sufficient condition which guarantees that all the eigenvalues of an interval matrix will lie inside a circle centered atαwith radiusris formulated. A design procedure of robust state feedback controllers for dynamic interval systems is demonstrated by an example.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677158

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A sealed‐off CO2laser with an intracavity structure and dual discharge sections has been built to test its lifetime under different treatments of cathodes. The output characteristics of this laser system, under different discharge conditions, have also been investigated. Several techniques, such as the sealing of optical components on a laser tube, the coating of tin‐oxide (SnO2) on stainless steel cathodes, and the making of a discharge tube of three layers, are established to construct this tube. By using SnO2coated SUS 304 cathodes and a gas mixture of CO2:N2:He:Xe:H2= 15:14:65:4:2 in this laser tube, an operational lifetime in excess of 1,800 hours and an output power up to 52W/m are obtained.

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677159

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0253-3839    

DOI:10.1080/02533839.1989.9677143

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor