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971.
972.
Jong Rak Park Gihan Ryu Jeongil Byun Heenam Hwang Sung Tae Kim Insun Kim 《Optical Review》2002,9(5):207-212
A numerical model based on Berreman’s 4 × 4 matrix approach was developed and used for computational simulation of a cholesteric liquid crystal (CLC) polarizer. Explicit expressions of the 4 × 4 propagation matrices for several optical films, which constitute a CLC polarizer, were presented. Numerical simulations for optical properties of a CLC layer, a linear polarizer and a CLC polarizer were executed, and the simulated results were found to be in fairly good agreement with measured results. 相似文献
973.
Polarisation fluctuations of the power spectrum with time in an optical fibre submarine cable installation are reported for the first time. It was found that the power spectrum of polarisation fluctuation was less than 60 Hz, and the maximum power spectrum was between 5Hz and 10Hz during the cable installation within a maximum cable tension of 18 kN (?1.8 tons) and a cable laying speed of 3.5 n mile/h, respectively. 相似文献
974.
Namihira Y. Horiuchi Y. Ryu S. Mochizuki K. Wakabayashi H. 《Lightwave Technology, Journal of》1988,6(5):728-738
Polarization fluctuation characteristics of optical-fiber submarine cable under 8000-m-deep sea environmental conditions, optical-fiber submarine cable coupling under periodic variable tension, and cable performance during and after installation, are presented. As a worst case, it is demonstrated that the maximum frequency spectrum of polarization fluctuation is less than 200 Hz under dynamic composite stress states. It is found that the polarization fluctuation of the optical-fiber submarine cable coupling changes linearly with periodic variable tensile forces. It is confirmed that the power spectrum of polarization fluctuations are less than 50~60 Hz, and the maximum power spectra are between 5 and 10 Hz during the cable installation within a maximum cable tension of 18 kN (1.8 tons) and the cable laying speed of 3.5 knots, respectively 相似文献
975.
976.
977.
[structure: see text] Five new urea derivative naphthalene compounds were synthesized by a reaction of 1,8-diaminonaphthalene and the corresponding isocyanates and showed a distinct color change only when treated with fluoride ions. 相似文献
978.
A criterion to determine the existence of zero-energy edge states is discussed for a class of particle-hole symmetric Hamiltonians. A "loop" in a parameter space is assigned for each one-dimensional bulk Hamiltonian, and its topological properties, combined with the chiral symmetry, play an essential role. It provides a unified framework to discuss zero-energy edge modes for several systems such as fully gapped superconductors, two-dimensional d-wave superconductors, and graphite ribbons. A variance of the Peierls instability caused by the presence of edges is also discussed. 相似文献
979.
Growth of SiC nanowires within stacked SiC fiber fabrics by a noncatalytic chemical vapor infiltration technique 总被引:1,自引:0,他引:1
Weon-Ju Kim Seok Min Kang Choong Hwan Jung Ji Yeon Park Woo-Seog Ryu 《Journal of Crystal Growth》2007,300(2):503-508
An atmospheric pressure chemical vapor infiltration (CVI) process without metallic catalysts was applied for the growth of SiC nanowires within stacked SiC fiber fabrics. We investigated the effect of the concentration of a reactant gas (CH3SiCl3, MTS) on the growth behavior and microstructure of the SiC nanowires. At high concentration of MTS in a H2+MTS mixture gas, one-dimensional (1D) SiC deposits with diameters of several hundreds of nanometers were formed. Microstructures of the 1D SiC deposits exhibited a strong positional dependency throughout the thickness direction of the stacked fabric due to a depletion of the MTS gas. On the other hand, single-crystalline SiC nanowires with average diameters of 50–60 nm could be obtained at a low concentration of MTS. The SiC nanowires also exhibited a homogeneous growth both in the plane of each fabric layer and throughout the thickness of the sample. 相似文献
980.
Hwa Jung Roh Gieun Kim Sung Cho Ji Yeon Ryu Junseong Lee Jae Nyoung Kim 《Tetrahedron letters》2018,59(15):1484-1488
Isatin-conjugated 3H-indole-N-oxides were synthesized from isatin-derived propargylic alcohols and nitrosobenzenes in moderate yields. Isatin-conjugated 3H-indole-N-oxides were converted to novel spiroindolenines under PPh3-mediated deoxygenation reaction condition, serendipitously. 相似文献