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991.
A distributed optical fiber sensor (DOFS) with the principle of microbend loss has been developed for concrete or rock-sliding damage measurement. The combination of multiple microbend sensors can form a sensor array for distributed sensing application in monitoring local slippage or deformation along the rock mass of the high slope, and the optical time-domain reflectometry (OTDR) can be conveniently used for interrogation of each sensor point. The sensor sensitivity can be obtained at a specific range according to the requirement of the model test condition. Connected with multiplexed sensing processing schemes, its sliding range of dynamic sensing response reached 0–3.6 mm and semi-empirical formula was fitted according to data from model tests. The DOFS array may find a potential application in real-time monitoring and damage detection of large and critical slope engineering structures. 相似文献
992.
We present results from a novel variational method for the study of beam propagation in a Kerr medium with nonlinear absorption. This new method combines the variational method and a nonlinear absorption equation and gives a concise expression for the combination. The results obtained with this method show good quantitative agreement with numerical solutions obtained with the finite-difference method. It is shown that the variational method takes much less time than a numerical simulation with the finite-difference method for analysis of beam propagation in a thick medium with nonlinear absorption and nonlinear refraction. The new method makes detailed analysis of beam propagation in a Kerr medium with nonlinear absorption very simple and fast. 相似文献
993.
We obtain the photonic bands and intrinsic losses for the triangular lattice three-component two- dimensional (2D) photonic crystal (PhC) slabs by expanding the electromagnetic field on the basis of waveguide modes of an effective homogeneous waveguide. The introduction of the third component into the 2D PhC slabs influences the photonic band structure and the intrinsic losses of the system. We examine the dependences of the band gap width and gap edge position on the interlayer dielectric constant and interlayer thickness. It is found that the gap edges shift to lower frequencies and the intrinsic losses of each band decrease with the increasing interlayer thickness or dielectric constant. During the design of the real PhC system, the effect of unintentional native oxide surface layer on the optical properties of 2D PhC slabs has to be taken into consideration. At the same time, intentional oxidization of macroporous PhC structure can be utilized to optimize the design. 相似文献
994.
We consider representations of the free group F
2 on two generators for which the norm of the sum of the generators and their inverses is bounded by some number μ ∈ [0, 4].
These μ-constrained representations determine a C*-algebra A
μ for each μ ∈ [0, 4]. If μ = 4, this gives the full group C*-algebra of F
2. We prove that these C*-algebras form a continuous bundle of C*-algebras over [0, 4] and evaluate their K-groups. 相似文献
995.
Qi-Jun Liu Zheng-Tang Liu Yun-Fang Liu Li-Ping Feng Hao Tian Jian-Gang Ding 《Solid State Communications》2010,150(41-42):2032-2035
We have investigated the structural parameters, electronic structure and optical properties of orthorhombic SrZrO3 using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory (DFT). Our calculated structural parameters are in good agreement with the previous theoretical and experimental data. Band structure, density of states and chemical bonding have been systematically studied. Furthermore, the complex dielectric function, refractive index, extinction coefficient, optical reflectivity, absorption coefficient, loss function and optical conductivity are calculated, which show an optical anisotropy in the components of polarization directions (100), (010) and (001). 相似文献
996.
We study the model M consisting of “general games” with noncompact action space, together with an associated abstract rationality function. We
prove that M is structurally stable and robust to ϵ-equilibria for “almost all” parameters. As applications, we investigate structural
stability and robustness to bounded rationality for noncooperative games, multiobjective optimizations and fixed point problems
satisfying existence and some continuity conditions. Specifically, we introduce concrete rationality functions for such three
kinds of problems with both payoffs and strategy sets, objective functions and domain spaces, and correspondence and domain
spaces as parameters, respectively, and show the generic structural stability and robustness to bounded rationality for the
corresponding model Ms. 相似文献
997.
A mid-infrared absorption strategy with calibration-free wavelength-modulation-spectroscopy (WMS) has been developed and demonstrated
for real-time, in situ detection of nitric oxide in particulate-laden combustion-exhaust gases up to temperatures of 700 K.
An external-cavity quantum-cascade laser (ECQCL) near 5.2 μm accessed the fundamental absorption band of NO, and a wavelength-scanned,
1f-normalized WMS with second-harmonic detection (WMS-2f/1f) strategy was developed. Due to the external-cavity laser architecture, large nonlinear intensity modulation (IM) was observed
when the wavelength was modulated by injection-current modulation, and the IM indices were also found to be strongly wavelength-dependent
as the center wavelength was scanned with piezoelectric tuning of the cavity. A quantitative model of the 1f-normalized WMS-2f signal was developed and validated under laboratory conditions. A sensor was subsequently designed, built and demonstrated
for real-time, in situ measurements of NO across a 3 m path in the particulate-laden exhaust of a pulverized-coal-fired power
plant boiler. The 1f-normalized WMS-2f method proved to have better noise immunity for non-absorption transmission, than wavelength-scanned direct absorption. A
0.3 ppm-m detection limit was estimated using the R15.5 transition near 1927 cm−1 with 1 s averaging. Mid-infrared QCL-based NO absorption with 1f-normalized WMS-2f detection shows excellent promise for practical sensing in the combustion exhaust. 相似文献
998.
999.
Monodisperse NiO nanocrystals with an average particle size of 3 ± 0.4 nm are successfully synthesized by the thermal decomposition of Ni-oleylamine complex in an organic solvent under a continuous O2 flux. The crystalline structure and the morphology of the product are investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Magnetization and alternating-current (ac) susceptibility measurements indicate that the structure of the particles can be considered as consisting of an antiferromagnetically ordered core and a spin-glass-like surface shell. In addition, both the exchange bias field and the vertical magnetization shift can be observed in this system at 10 K after field cooling. This observed exchange bias effect is explained in terms of the exchange interaction between the antiferromagnetic core and the spin-glass-like shell. 相似文献
1000.
Feng Cheng Wei‐Xi Li Chao‐Jiang Xu 《Mathematical Methods in the Applied Sciences》2017,40(14):5161-5176
In this paper, we consider the inviscid limit for the periodic solutions to Navier–Stokes equation in the framework of Gevrey class. It is shown that the lifespan for the solutions to Navier–Stokes equation is independent of viscosity, and that the solutions of the Navier–Stokes equation converge to that of Euler equation in Gevrey class as the viscosity tends to zero. Moreover, the convergence rate in Gevrey class is presented. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献