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101.
We report a systematic, experimental, and theoretical investigation on the surface plasmon resonance (SPR) sensing using optical disks with different track pitches, including Blu-ray disk (BD), digital versatile disk (DVD), and compact disk (CD). Optical reflection measurements indicate that CD and DVD exhibit much higher SPR sensitivity than BD. Both experiments and finite-difference time-domain simulations reveal that the SPR sensitivity is significantly affected by the diffraction order of the SPR peaks and higher diffraction order results in lower sensitivity. Numerical simulations also show that very high sensitivity (~1600 nm per refractive index unit) is achievable by CDs. 相似文献
102.
In this Letter we present turbulent flame speeds and their scaling from experimental measurements on constant-pressure, unity Lewis number expanding turbulent flames, propagating in nearly homogeneous isotropic turbulence in a dual-chamber, fan-stirred vessel. It is found that the normalized turbulent flame speed as a function of the average radius scales as a turbulent Reynolds number to the one-half power, where the average radius is the length scale and the thermal diffusivity is the transport property, thus showing self-similar propagation. Utilizing this dependence it is found that the turbulent flame speeds from the present expanding flames and those from the Bunsen geometry in the literature can be unified by a turbulent Reynolds number based on flame length scales using recent theoretical results obtained by spectral closure of the transformed G equation. 相似文献
103.
Wireless Personal Communications - With the development of big data computing technology, most documents in various areas, including politics, economics, society, culture, life, and public health,... 相似文献
104.
105.
A partial variational analysis of planar dielectric antennas 总被引:2,自引:0,他引:2
The reflection and radiation characteristics of a planar dielectric antenna with arbitrary geometrical configuration are analyzed numerically. A variational equation is first established based on the partial variational principle (PVP), and then solved by the finite element method coupled with the frontal solution technique. The radiation and boundary conditions are incorporated by combining the modal expansion method and the Green's function approach for exterior field representation. The reflection coefficients, the radiation patterns, and the directive and power gains of several antennas with linearized structures are studied and compared 相似文献
106.
E.Y.B. Pun S.A. Zhao K.K. Loi P.S. Chung 《Photonics Technology Letters, IEEE》1991,3(11):1006-1008
Proton-exchanged optical waveguides have been fabricated in z-cut LiNbO/sub 3/ using a new proton source: stearic acid. These waveguides were characterized optically and were found to exhibit a step index profile with Delta n=0.118 measured at 0.633 mu m. The propagation losses were typically around 1.5 dB/cm, and the diffusion constant and the activation energy for the proton-exchange process were measured to be 5*10/sup 6/ mu m/sup 2//h and 69 kJ/mol, respectively.<> 相似文献
107.
San-Liang Lee Youngchul Chung Coldren L.A. Dagli N. 《Quantum Electronics, IEEE Journal of》1995,31(10):1790-1802
We propose an analytic method to calculate the leaky mode functions to enable modal expansion without encountering the normalization and orthogonality problems of the unphysical mode shape. The wave functions of leaky modes are derived from the explicit formulas of normalized radiation modes. Using leaky modes to approximate a continuum of radiation modes greatly simplifies the analysis of excitation, transitions, propagation, and radiation of light waves in multilayer waveguide structures. Upon comparison with the beam propagation method and modal propagation method, we show that the leaky mode approximation while requiring a much simpler computation is as accurate. This method can also provide better physical insight to device operations 相似文献
108.
Chang Kyung Sung Sae-Young Chung Jun Heo Inkyu Lee 《Communications, IEEE Transactions on》2007,55(9):1649-1655
If the channel is static and is perfectly known to both the transmitter and the receiver, the water-filling technique with adaptive modulation is known to be optimal (Gallager, 1968). However, for orthogonal frequency-division multiplexing (OFDM) systems, this requires intensive traffic overheads for reporting channel state information on all subcarriers to the transmitter. In this paper, we consider an adaptive modulation and coding scheme for bit-interleaved coded OFDM with reduced feedback information satisfying a specified quality of service level. We propose a rate adaptation scheme, which utilizes the estimated bit error rate for supportable transmission rates. In this scheme, a user equipment chooses a modulation and coding scheme (MCS) level, which can provide the maximum spectral efficiency based on one OFDM symbol rather than on all subchannels. Then the user needs to send back only the selected MCS level index. The proposed scheme does not require the water-filling procedure, and the amount of the feedback information reduces to a single integer value irrespective of the number of subcarriers. Simulation results show that the proposed scheme can significantly reduce the system complexity while minimizing the performance loss compared to the optimum water-filling scheme. 相似文献
109.
External force of snake: virtual electric field 总被引:1,自引:0,他引:1
Hyun Keun Park Myung Jin Chung 《Electronics letters》2002,38(24):1500-1502
Gradient vector flow (GVF) is an external force of snake that overcomes traditional snake's problems: limited capture range and poor convergence to concave boundaries. A new external force with the same properties as the GVF is proposed. The proposed method has much shorter computational time than the GVF. 相似文献
110.
Benzo[c]phenanthridine skeleton was synthesized from easily available starting N-methyl-o-toluamide 2 and o-methylbenzonitrile 5 in 7 steps. Radical cyclization of styrene 10 afforded 6,11-dimethyl-6,11-dihydro-5H-indeno[1,2-c]isoquinolin-5-one 13. Most 3-arylisoquinolines have displayed strong activities against human tumor cell lines. Especially, indenoisoquinolinone 13 exhibited excellent cytotoxicity (IC50 = 0.002 microgram/ml; HCT 15). 相似文献