Thermal resistance of ridge-waveguide laser diodes based on GaAs,GaSb or InP

The effects of different substrates (GaAs, GaSb and InP) on the thermal properties of laser diodes with a ridge-waveguide structure are presented. Laser diodes with the same basic geometry exhibit different thermal resistances. The reason is therefore the difference in thermal conductivity of the substrates and the active layer compounds. This leads to different temperature distributions in the structures. The theoretical results were supported by experimental data.

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Zusammenfassung Es wurde der Einfluß verschiedener Substrate (GaAs, GaSb und InP) auf die thermischen Eigenschaften von Laserdioden mit gefurchter Hohlleiterstruktur untersucht. Laserdioden mit dem gleichen geometrischen Grundaufbau zeigen verschiedene Wärmewiderstände. Die Ursache ist folglich der Unterschied in der Wärmeleitfähigkeit der Substrate und der Verbindungen der aktiven Schicht. Dies führt zu einer unterschiedlichen Temperaturverteilung in der Strukturen. Theoretische Ergebnisse werden durch experimentelle Daten bekräftigt.

     

Structural and Kinetic Aspects of Blood Plasma Protein Adsorption on the Surface of Hydrophobic Polymers

Abstract

Due to the wide use of polymers in medicine, researchers are required to solve a very important problem–to understand the interaction between materials of nonphysiological origin and the surrounding biological liquids, and tissues, particularly blood.     

A simple method for extracting both active oily and water soluble extract (WSE) from Nigella sativa (L.) seeds using a single solvent system

The current study provides a way of extraction for both active NSO and WSE from Nigella sativa seeds using 98% methanol. About 1?kg of ground seeds was macerated by 1:2.5 w/v (g/mL) for 72?hours. After rotary evaporation and 7 days of continuous drying and chilling at 50 and 4?°C, NSO and WSE were obtained at the same instant. Solubility tests of 24 solvents and 11 thin layer chromatographic analyses while 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging assay of NSO (73.66) , WSE (33.32) and NSO?+?WSE (78.22) against ascorbic acid (IC50?=?4.28?mg/mL) was performed. WSE was found to be highly soluble in water and 5% NaOH exhibiting the same Rf value of 0.95 for EtOH:DMSO (9:1) against the honey. WSE has revealed more than twofold higher anti-oxidant activity than others. Formulation of WSE with Tualang honey may provide better targeted hydrophilic drug delivery systems.     

高聚合度Ⅱ-型聚磷酸铵的合成

用聚合反应-热处理两段工艺合成了高聚合度的聚磷酸铵（APP）阻燃材料,其结构经XRD,粒度及平均聚合度表征。优化反应条件为：磷酸氢二铵1mol,n（磷酸氢二铵）：n（五氧化二磷）：n（脲）：1．0：1．0：0．3．干燥氨气氛下于290℃反应30min,再经250℃-280℃后处理100min-110min。APP的平均聚合度大于150,粒度小于50μm。     

Stabilized finite element method for flows with multiple reference frames

We present a space‐time finite element method capable of dealing with flows in multiple co‐rotating reference frames. Since equal order interpolation is used for all degrees of freedom, Galerkin/least‐squares stabilization is applied. We give a detailed derivation of the equations involved, introduce the variational form, present the stabilization parameters, and also discuss implementation issues. Numerical examples in 2D and 3D show generality and efficiency of the method, if steady‐state behavior of rotating components is sufficient for the CFD analysis. Copyright © 2015 John Wiley & Sons, Ltd.