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1.
We study experimentally and theoretically two polarization effects in a vertical cavity surface emitting laser submitted to optical feedback. In a first experiment, we obtain flips between two linearly polarized laser modes up to a frequency of 50 MHz using an external cavity with a polarizer. In a second experiment, polarization self modulation is demonstrated up to a frequency of 2.6 GHz, using a quarter wave plate instead. Numerical calculations, based on a four levels model for the active medium, show a good agreement with the experiments. 相似文献
2.
David?Pérez-Martínez C.?Alvarez-Salas J.?A.?Morales-Rueda J.?F.?Toro-VazquezEmail author M.?Charó-Alonso E.?Dibildox-Alvarado 《Journal of the American Oil Chemists' Society》2005,82(7):471-479
The solid fat content (SFC), Avrami index (n), crystallization rate (z), fractal dimension (D), and the pre-exponential term [log(γ)] were determined in blends of cocoa butter (CB) with canola oil or soybean oil crystallized
at temperatures (T
Cr) between 9.5 and 13.5°C. The relationship of these parameters with the elasticity (G′) and yield stress (σ*) values of the crystallized blends was investigated, considering the equilibrium melting temperature (T
M
o) and the supercooling (i.e., T
Cr
o−T
M
o) present in the blends. In general, supercooling was higher in the CB/soybean oil blend [T
M
o=65.8°C (±3.0°C)] than in the CB/canola oil blend [T
M
o=33.7°C (±4.9°C)]. Therefore, under similar T
Cr values, higher SFC and z values (P<0.05) were obtained with the CB/soybean oil blend. However, independent of T
Cr TAG followed a spherulitic crystal growth mechanism in both blends. Supercooling calculated with melting temperatures from
DSC thermograms explained the SFC and z behavior just within each blend. However, supercooling calculated with T
M
o explained both the SFC and z behavior within each blend and between the blends. Thus, independent of the blend used, SFC described the behavior of G′eq and σ* and pointed out the presence of two supercooling regions. In the lower supercooling region, G′eq and σ* decreased as SFC increased between 20 and 23%. In this region, the crystal network structures were formed by a mixture of
small β′ crystals and large β crystals. In contrast, in the higher supercooling region (24 to 27% SFC), G′eq and σ* had a direct relationship with SFC, and the crystal network structure was formed mainly by small β′ crystals. However, we
could not find a particular relationship that described the overall behavior of G′eq and σ* as a function of D and independent of the system investigated. 相似文献
3.
Char Booth 《国际互联网参考资料服务季刊》2013,18(2-3):147-165
ABSTRACT Internet voice and video calling have demonstrated a dramatic rise in quality in the past several years and have quickly become communication technologies with a disruptive impact on society. Librarians, who regularly adopt such technologies in outreach and public services, should evaluate Web-calling programs as potential sources of innovative reference programming. This article describes the development of Skype video and Internet telephony pilot reference services at the Ohio University Libraries and considers the utility of Skype and VoIP in a library setting. 相似文献
4.
Younghun Sung Jaehoon Lim Jai Hyun Koh Byoung Koun Min Jeffrey Pyun Kookheon Char 《Korean Journal of Chemical Engineering》2016,33(8):2287-2290
Pt-decorated CdSe tetrapods with different arm lengths were tested for the photocatalytic hydrogen generation reaction. Well-defined CdSe tetrapods with controlled wurtzite arm lengths were synthesized by the continuous precursor injection (CPI) approach. Pt nanocrystals with an extremely small size of ~1 nm were directly decorated on the overall surfaces of CdSe tetrapods. Ligand-exchanged Pt-decorated CdSe tetrapods with different arm lengths were employed as photocatalysts for photocatalytic hydrogen generation reaction in the presence of hole scavengers. Pt-decorated CdSe tetrapods with shorter arm length showed the highest photocatalytic efficiency, which is due to higher probability of charge separation. 相似文献
5.
B. L. Narasimha Char B. R. Reddy S. D. Thirumala Rao 《Journal of the American Oil Chemists' Society》1977,54(11):494-495
Stones of mango fruit (Mangifera indica) were processed for recovery of fat and the fat refined. Mango kernel fat is potentially edible and can substitute for tallow and cacao butter. Mango kernal meal can be used as a sizing material and as a feed. 相似文献
6.
7.
The effect of injection molding conditions and reactive compatibilization on the morphology of maleic anhydryde‐modified poly(phenylene oxide)/polyamide‐6 blends was investigated. The injection flow rate primarily influenced the position of the subskin layer, and the injection temperature affected the aspect ratio of the dispersed phase. A reduction of the sue of the dispersed phase occured during the converging flow in the barrel‐to‐sprue zone. The reactive compatibilization reduced the flow induced deformation, the coalescence and the breakup of particles and improved the dispersion of the minor phase. 相似文献
8.
Jinseob Shin Kyomin Shin Hanna Lee Jeong‐Beom Nam Jae‐Eun Jung Jee‐Hyun Ryu Joo‐Hyun Han Kyung‐Do Suh Yong‐Jin Kim Jongwon Shim Junoh Kim Sang‐Hoon Han Kookheon Char Yeon Kyung Kim Jin Ho Chung Min Jung Lee Byeong Cheol Kang Jin‐Woong Kim 《Advanced materials (Deerfield Beach, Fla.)》2010,22(6):739-743
9.
10.