基于不规则U型结构的高灵敏度太赫兹微流传感器

设计了一种基于不规则U型结构的高灵敏度太赫兹微流传感器,通过仿真软件研究了传感器金属结构中金属线的长度、宽度与夹角对品质因数与吸收率的影响,以及微流通道高度与盖层厚度对传感器性能的影响,最后仿真计算了传感器对不同质量分数葡萄糖溶液的检测性能.结果 表明:传感器的最佳结构参数为L1=84 μm、L2=82μm、L3 =5...     

一种测量无规则裂缝宽度的量化模型与实现

建立了一种测量无规则裂缝宽度的量化模型,提出了一种真伪裂缝区域分割新方法.该方法通过边缘检测并利用形态学膨胀运算,在待测裂缝的两侧边缘区域选取近似等量的目标像素和背景像素后,设置门限以自适应选取最佳分割阈值,提取出裂缝区域,进而提取裂缝的走势及边缘像素,用建立的量化模型,即可实现宽度测量.该测量方法能有效克服裂缝图像的噪音较大、裂缝不规则等弊端,去除裂缝图像的伪裂缝区域,测量结果的重复准确度在0.1 mm以内.实验结果表明,该方法有效地实现了裂缝宽度的准确测量,具有较强的适应性.     

一种测量无规则裂缝宽度的量化模型与实现

建立了一种测量无规则裂缝宽度的量化模型,提出了一种真伪裂缝区域分割新方法.该方法通过边缘检测并利用形态学膨胀运算,在待测裂缝的两侧边缘区域选取近似等量的目标像素和背景像素后,设置门限以自适应选取最佳分割阈值,提取出裂缝区域,进而提取裂缝的走势及边缘像素,用建立的量化模型,即可实现宽度测量.该测量方法能有效克服裂缝图像的噪音较大、裂缝不规则等弊端,去除裂缝图像的伪裂缝区域,测量结果的重复准确度在0.1mm以内.实验结果表明,该方法有效地实现了裂缝宽度的准确测量,具有较强的适应性.     

Irregular dielectric or permeable bodies in an external field

An integral equation is derived for the electrostatic potential ψ that arises when a uniform dielectric body of arbitrary shape is placed in an applied electrostatic field. By expansion of ψ in a certain basic set, the integral equation becomes a set of linear equations for the expansion coefficients, and it is often practical to solve the set by truncation. As a test, the equations are applied to the problem of a spheroid in a uniform field, and they easily yield the standard results that are usually derived by introducing spheroidal harmonics. Either the integral equation or the equivalent linear equations can be solved in an iterative approximation (the analog of the Born approximation) when the dielectric constant of the body is not too far from unity. For bodies that differ from spherical or cylindrical ones by a small parameter λ, perturbation formulae are derived that solve the equations in powers of λ. The problem of a homogeneous permeable body of arbitrary shape in an external magnetostatic field is reducible to the dielectric problem, but in addition an alternate integral equation for the magnetic problem is discussed.     

Transport of a Passive Tracer by an Irregular Velocity Field

The trajectories of a passive tracer in a turbulent flow satisfy the ordinary differential equation x′(t)=V(t,x(t)), where V(t,x) is a stationary random field, the so-called Eulerian velocity. It is a nontrivial question to define the dynamics of the tracer in the case when the realizations of the Eulerian field are only spatially Hölder regular because the ordinary differential equation in question lacks then uniqueness. The most obvious approach is to regularize the dynamics, either by smoothing the velocity field (the so-called ε-regularization), or by adding a small molecular diffusivity (the so-called κ-regularization) and then pass to the appropriate limit with the respective regularization parameter. The first procedure corresponds to the Prandtl number Pr=∞, while the second to Pr=0. In the present paper we consider a two parameter family of Gaussian, Markovian time correlated fields V(t,x), with the power-law spectrum. Using the infinite dimensional stochastic calculus we show the existence and uniqueness of the law of the trajectory process corresponding to a given field V(t,x) for a certain regime of parameters characterizing the spectrum of the field. Additionally, this law is the limit, in the sense of the weak convergence of measures, of the laws obtained as a result of any of the described regularizations. The so-called Kolmogorov point, that corresponds to the parameters characterizing the relaxation time and energy spectrum of a turbulent, three dimensional flow, belongs to the boundary of the parameter regime considered in the paper.     

An Efficient Model for Layer-by-Layer Analysis of Sandwich Irregular Cylindrical Shells of Revolution

Based on the approach of layer-by-layer analysis, we consider an algorithm for constructing finiteelement models of layers for a refined calculation of the stress-strain state of sandwich cylindrical shells with the application of efficient approximations that increase the rate of convergence of the numerical results and, consequently, allow the order of the systems of equations to be reduced, which is particularly topical in the layer-bylayer analysis of laminated inhomogeneous constructions. An example of applying the models considered to calculate the stress-strain state of a sandwich cylindrical shell with through and non-through cuts is given.     

On the Gradient-Current Mechanism of Formation of the Irregular Structure of the High-Latitude Upper Ionosphere

We consider the gradient-current instability of an inhomogeneous magnetoactive plasma in the approximation of double-fluid magnetohydrodynamics. Unlike the known gradient-drift and current-convective instabilities, the gradient-current instability is related to generation of nonpotential quasistatic electric fields polarized orthogonal to the external magnetic field B ₀ and excited by eddy currents whose density vector lies in the plane passing through the vectors of the magnetic field B ₀ and large-scale electron-density gradient. It is shown that in the high-latitude upper ionosphere, in the regions containing large-scale currents flowing in and out of the ionosphere along the magnetic field, the gradient-current instability can lead to the appearance of sheet-like irregularities extended predominantly in the plane passing through the geomagnetic-field and regular plasma-drift velocity vectors. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 48, No. 7, pp. 574–587, August 2005.     

Relevance of the Slip Condition for Fluid Flows Near an Irregular Boundary

We consider the Navier-Stokes equation in a domain with a rough boundary. The roughness is modeled by a small amplitude and small wavelength oscillation, with typical scale e << 1{\varepsilon \ll 1}. For periodic oscillation, it is well-known that the best homogenized (that is regular in e{\varepsilon}) boundary condition is of Navier type. Such result still holds for random stationary irregularities, as shown recently by the first author [5, 15]. We study here arbitrary irregularity patterns.     

Consecutive Parametric Interactions of Light Waves with Nonmultiple Frequencies in Crystals with Irregular Poled Structure

A stochastic theory of quasi-phase-matched consecutive processes, which takes into account peculiarities of the method of creating a nonlinear lattice in crystals, is developed. The influence of aperiodicity of a certain type on the efficiency of the process of consecutive parametric interaction of light waves with nonmultiple frequencies in crystals with irregular poled structure is studied. It has been established that in aperiodically poled nonlinear crystals the regime of exponentially changing intensity of interacting waves can be implemented. A particular case of nondegenerate parametric amplification is also discussed.     

Irregular frequency chirp in radiation of an injection laser in high-velocity code modulation

The effect of the shape of the excitation pulses on the magnitude of the frequency chirp in an injection laser is investigated. It is established that as the degree of rectangularity of the pulses becomes higher, the frequency chirp increases. Simultaneous consideration of the effect of residual charge in the active region of the laser, the delay of stimulated radiation, and the frequency chirp indicates that in the case of high-velocity code modulation of an injection laser, in the latter an irregular frequency chirp appears that can exert a noticeable influence on the distortion of code trains of pulses having a super-Gaussian shape, when they propagate in media with a dispersion of 100 p.s./nm/km and above. Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 45–49, January–February, 1997.     

Inhomogeneous Site Percolation on an Irregular Bethe Lattice with Random Site Distribution

In this paper, we study inhomogeneous site percolation on an irregular Bethe lattice, for considering that percolation often occurs on irregular grids or lattices with variable site neighbours in real-world problems. The explicit expression for cluster-size distribution of this percolation is derived based on probability theory. Moreover, the exact formulas for critical occupation probability, mean cluster size, and percolation probability are obtained using generating function method and generalised recursive approach. In addition, sensitivity analysis and numerical simulation are given to deepen and illustrate the results.     

Studies of the Irregular Structure of the Ionosphere using Scattering of Radio Waves on Artificial Periodic Inhomogeneities

We present new results of our studies of the irregular structure of the ionosphere using artificial periodic inhomogeneities (APIs) of the ionospheric plasma. The observations were carried out from 9:00 to 17:00 in August 10–12, 1999 with a height step of 0.7 km and digital registration and real-time processing of the signal quadratures. It is shown that in many cases, the amplitude of the scattered signal is determined by the interference of radio waves scattered on APIs and on natural ionospheric formations including sporadic layers and large-scale natural irregularities. This allows one to study the irregular structure of the lower ionosphere by analyzing height-time dependences of the amplitude and phase of the scattered signal.     

手征–夸克耦合与双重子结构

运用SU(3)手征夸克模型,系统地研究了H,d*和d＇三个六夸克体系的结构,分析了SU(3)手征场和矢量耦合禁闭势等非微扰效应对三种六夸克态能量的影响.结果发现,SU(2)手征场的耦合,对形成六夸克态是有利的,但是扩大到SU(3)手征对称,则由于这些手征场的“云”,对六夸克系统形成束缚的双重子态起到了限制的作用,矢量耦合禁闭势有利于H的形成,而对d*则相反.     

Coupling Coefficient of Irregular Microstrip Resonators

We prove the equivalence of the resonance and energetic definitions of the coupling coefficient in the case of irregular microstrip resonators. Formulas for calculation of the coupling coefficient of microstrip resonators with stepped width of the strip conductor are derived. The presence of a region in which the coupling coefficient increases with increase in spacing between the resonators is shown.     

推广的相互作用玻色子模型中基于对偶代数结构的量子相变研究(英文)

本工作将相互作用玻色子模型推广为包含f-和p-玻色子的情形。利用仿射型代数方法,通过对偶代数结构数值计算了多分量玻色型对力问题。利用对偶关系解析构建了与哈密顿量及其基底相联系的,由幺正的粒子数守恒和非粒子数守恒算符构成的准旋代数。在经该模型对106-116Cd偶偶核素实验能谱拟合的基础上,计算了基态和低激发态中各种玻色子占有率,准γ带中相邻能级摇摆等几个能特征该区域核素形状相变的序参量。从而展示了这些中重质量核从振动到γ-不稳定运动的形状相变行为。An extension of the original interacting boson model to the multi-level case including negative parity f-and p-bosons is made. An affinealgebraic approach is applied to solve the multi-level pairing problem numerically via the dual algebraic structure. The duality relation is explicitly used to construct the number-conserving unitary and number-nonconserving quasi-spin algebra, related with the Hamiltonian and the corresponding bases. After fitting to the experimental level energies of even-even 106-116Cd, several order parameters to signify the shape (phase) transition, such as occupation numbers of the bosons in the ground and a few lowest excited states, the level energy staggering in the (quasi)-γ band, are calculated to demonstrate the shape (phase) transitional behavior of these medium mass transitional nuclei.     

The Algebraic Structure of the Thirring Model

We summarize the representation theory of the group SU(1,1) as needed for the massless Thirring model. Representations of the current operator algebra are given taking account of conformal covariance. The conformal covariance transformation behaviour of the Thirring field is investigated. The Haag-Araki-Kastler observable algebra of the Thirring field is reconstructed from the Wightman theory of this model.