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81.
82.
The phenomenon of stochastic resonance in a bistable system with time-delayed feedback driven by non-Gaussian noise is investigated. Combining the small time delay approximation, the path-integral approach and the unified colored noise approximation, a general approximate Fokker–Planck equation of a stochastic system is obtained. The effects of the parameter q indicating the departure from the Gaussian noise, the delay time τ , and the correlation time τ0 of the non-Gaussian noise on the quasi-steady-state probability distribution function (SPD) and the signal-to-noise ratio (SNR) are discussed. It is found that the number of peaks in SPD and the reentrant transition between one peak and two peaks and then to one peak again in the curve of SNR depends on the parameter q, the delay time τ , and the noise correlation time τ0. 相似文献
83.
Ji-Zhou Kong Fei Zhou Zheng Wang Chuan-Bao Wang Mei-Ling Wang Kang-Min Chen Xue-Mei Wu Kong-Jun Zhu Jin-Hao Qiu 《Journal of Sol-Gel Science and Technology》2012,63(1):95-102
High-quality c-axis oriented Al and Er co-doped ZnO films were prepared on the quartz glasses by sol?Cgel method. In order to obtain the optimal processing parameters for the growth of the oriented film, an L16 (45) orthogonal experimental design was chosen. The experimental results show the rank of 5-factors as follows: Er at.%?>?the number of coating layer?>?annealing temperature?>?Al at.%?>?the concentration of the sol. The Al and Er co-doped film prepared using the optimal parameters exhibits the preferential orientation along the c-axis perpendicular to the substrate surface. In addition, the structural, morphological and optical properties of the films were studied by X-ray diffraction, scanning electron microscopy, and UV?Cvisible spectrophotometer, respectively. The photoluminescence spectra were also used to characterize the luminescence properties of the samples. It is found that when ZnO was co-doped with 7?% Al and 1.5?% Er, the blue emission centered at 465?nm disappears and the green emission centered at 547?nm increases with a blue shift, resulted from the rapid reducing of the interstitial Zn defect, and increasing of the oxygen defects and vacancies caused by Al3+ and Er3+ dopants. 相似文献
84.
Daohai Xie Bensheng Qiu Jiangyang Zhang Xiaoming Yang 《Applied magnetic resonance》2010,39(4):373-380
The aim of this study was to evaluate the capability of using micro-magnetic resonance imaging (MRI) to visualize and characterize
atherosclerotic plaques of mouse models. Twenty five apolipoprotein E-knockout mice were fed atherogenic diet, which enabled
creation of aortic atherosclerotic plaques. Aortic plaques were examined in vivo by 4.7 T MRI and then characterized ex vivo
by 11.7 T three-dimensional MRI. MR images were correlated with subsequent histological confirmation. In vivo 4.7-T MRI demonstrated
unevenly thickened aortic walls due to formation of atherosclerotic plaques. Ex vivo 11.7-T MRI enabled not only to acquire
full volume-rendered images of the entire vessels but also to characterize plaque components (such as lipid cores and fibrous
caps) at any level and any projection, which were confirmed by histological correlation. Micro-MRI provides an excellent imaging
tool for basic science to investigate atherosclerosis in small animal models, which may become a supplement to histopathology
of atherosclerotic cardiovascular disease. 相似文献
85.
Using the thermo entangled state representation and based on the thermo Wigner operator we first introduce the thermo Husimi operator, which turns out to be a projective operator of the thermo squeezed coherent state, therefore the positive definite property of Husimi distribution function can be insured. In addition, we find the use of the thermo Husimi operator in simplifying the form of master equations. 相似文献
86.
On a Hilbert-type linear series operator and its applications 总被引:1,自引:0,他引:1
Jianjun Jin 《Journal of Mathematical Analysis and Applications》2010,371(2):691-704
This paper deals with a Hilbert-type linear series operator and its norm. Several generalizations of the Hilbert-type inequalities whose kernels are symmetric and homogeneous of the first order are presented. Included are applications of some new extended Hilbert-type inequalities with the best possible constant factors and the equivalent forms are established. Also, the reverse forms and some particular forms are obtained as special cases of the results of this paper. 相似文献
87.
In this paper, we discuss two classes of parameterized block triangular preconditioners for the generalized saddle point problems. These preconditioners generalize the common block diagonal and triangular preconditioners. We will give distributions of the eigenvalues of the preconditioned matrix and provide estimates for the interval containing the real eigenvalues. Numerical experiments of a model Stokes problem are presented. 相似文献
88.
LCOS大屏幕薄型背投电视广角投影物镜的设计 总被引:2,自引:1,他引:1
为了满足67英寸大屏幕LCOS背投电视的需要,设计了一款广角投影物镜.此广角投影镜头采用远心反远距结构,通过合理选用非球面和光学材料,设计的镜头具有视场大、投影距离短、工作距离长、相对孔径大、无渐晕、辐照度均匀等优点.在LCOS芯片奈奎斯特空间频率处的调制传递函数值高于0.5,色差仅约1/4像元,畸变低于5‰. 相似文献
89.
90.