相对转动动力学方程的稳定性及在一类黏弹性系数下的解

建立圆柱体任意两个截面间的一般黏弹性转动力学方程，讨论了相对转角的稳定性，由于此方程为变系数的二阶线性的非齐次常微分方程组，没有统一的求解方法.因此，针对其中的一类黏弹性系数求得其解. 关键词： 变系数方程的解 相对转角 稳定性     

Regenerative synthesis of copper nanoparticles by?photoirradiation

Copper nanoparticles have attracted much attention because of their low cost, and because their use can contribute toward the sustainability of metal resources. In this study, copper nanoparticles were synthesized by the photoirradiation of copper acetate solution at room temperature. The diameter and chemical composition of the obtained copper nanoparticles were analyzed using field-emission scanning electron microscope (FE-SEM) spectrophotometer and an X-ray photoelectron spectrometer. Well-dispersed copper nanoparticles with  ~5 nm in diameter were observed in the solution. On the other hand, when the nanoparticle solution was exposed to fresh air, nanoparticles were not observed in the solution. Furthermore, the copper nanoparticles were recovered from a solution of decomposed nanoparticles by re-photoirradiation.     

平面介质波导折射率剖面重建的欠松弛迭代方法

本文研究存在导(行)模时Gel'fand-Levitan-Marchenko方程的数值解法。由于反射系数在复数k平面正虚数轴上有极点,其特征函数中出现指数增长项,应用数值迭代求解到一定距离后便产生发散。为了克服这一困难,我们在迭代中采用了松弛方法,通过引入欠松弛因子延伸了势函数重建的有效距离。应用Schrodinger方程下的比例变换关系,逆散射所重建势函数可以直接用于介质波导折射率剖面设计。     

BLM成膜液中胆固醇与卵磷脂相互作用的光谱学研究

结合胆固醇与卵磷脂的拉曼光谱,分析了BLM成膜液中胆固醇与卵磷脂的相互作用。得出膜液中胆固醇与卵磷脂的最佳配比为1∶4。室温下,电化学实验的结果表明,以此种比例配置的膜液使膜的稳定性得到提高,导电率减小。     

低频响及低采样频率下用布朗运动分析法测量光阱刚度

布朗运动法测量光阱刚度因其简便易行而成为光镊系统参数测量的一种常用的方法，但是由于在低频响或低采样频率时测量结果误差很大，所以主要用在频响及采样频率较高的情况下.将在功率谱分析及实验的基础上，讨论如何在低频响及低采样频率下，用布朗运动法测量光阱刚度. 关键词： 布朗运动 光阱刚度 光镊 功率谱     

Coexistence of single-mode and multi-longitudinal mode emission in the ring laser model

A homogeneously broadened unidirectional ring laser can emit in several longitudinal modes for large enough pump and cavity length because of Rabi splitting induced gain. This is the so called Risken-Nummedal-Graham-Haken (RNGH) instability. We investigate numerically the properties of the multi-mode solution. We show that this solution can coexist with the single-mode one, and its stability domain can extend to pump values smaller than the critical pump of the RNGH instability. Moreover, we show that the multi-mode solution for large pump values is affected by two different instabilities: a pitchfork bifurcation, which preserves phase-locking, and a Hopf bifurcation, which destroys it.     

The Vlasov–Poisson System with Infinite Mass and Energy

This paper deals with solutions to the Vlasov–Poisson system with an infinite mass. The solution to the Poisson equation cannot be defined directly because the macroscopic density is constant at infinity. To solve this problem, we decompose the solution to the kinetic equation into a homogeneous function and a perturbation. We are then able to prove an existence result in short time for weak solutions to the equation for the perturbation, even though there are no a priori estimates by lack of positivity.     

Generalized Boundary Conditions in an Existence and Uniqueness Proof for the Solution of the Non-Stationary Electron Boltzmann Equation by Means of Operator-Semigroups

Recently, based on the semigroup approach a new proof was presented of the existence of a unique solution of the non-stationary Boltzmann equation for the electron component of a collision dominated plasma. The proof underlies some restrictions which should be overcome to extend the validity range to other problems of physical interest. One of the restrictions is the boundary condition applied. The choice of the boundary condition is essential for the proof because it determines the range of definition of the infinitesimal generator and thus the operator semigroup itself. The paper proves the existence of a unique solution for generalized boundary conditions, this solution takes non-negative values, which is necessary for a distribution function from the physical point of view.     

Chemical Analysis of Patterned Mask Cleaning in Organic Light Emitting Diode Fabrication with Raman Spectroscopy

Abstract

Despite the continually improving efficiency of the fabrication process used to manufacture the organic light emitting diode (OLED) emitter layer, which uses a shadow mask, a method for the cleaning and recycling of the shadow mask is still lacking. One of the main reasons for this is the absence of a quantitative/qualitative method to analyze the cleaning solution using simple in situ measurements. Recently, Raman analysis has become popular because of its convenience, ease of use, and suitability for in situ measurements. Thus, Raman spectroscopy has the capacity to analyze the solution used for cleaning shadow masks. A particular advantage of this approach is that it can detect organic contaminants in the cleaning solution, which are caused by the residue that remains on the shadow mask after the OLED emitter layer fabrication process. Raman spectroscopy has an advantage for analyzing solution condition and contaminant detection between the cleaning solution and organic chemical by using the Raman peak and fluorescence integration method.     

Well Posedness for Pressureless Flow

We study the uniqueness problem for pressureless gases. Previous results on this topic are only known for the case when the initial data is assumed to be a bounded measurable function. This assumption is unnatural because the solution is in general a Radon measure. In this paper, the uniqueness of the weak solution is proved for the case when the initial data is a Radon measure. We show that, besides the Oleinik entropy condition, it is also important to require the energy to be weakly continuous initially. Our uniqueness result is obtained in the same functional space as the existence theorem. Received: 26 September 2000 / Accepted: 25 April 2001     

On reflection from a suddenly created plasma half-space: transientsolution

The reflection by a suddenly created plasma half-space of a time-harmonic plane electromagnetic wave propagating in free space is considered. The problem involves a temporal discontinuity, a spatial discontinuity, and a dispersive medium. The steady-state solution is obtained by considering the basic features of the scattering processes due to each of the discontinuities in terms of analogous transmission-line models. The electric field of the reflected wave consists of two components. One component (called component A) is of the same frequency as the incident wave frequency and is due to the spatial discontinuity. The other component (called component B) is of a different frequency and arises because of the temporal discontinuity. The B component is damped out even if the plasma is only slightly lossy. The damping rate of the B component is calculated. The transient solution is obtained through the use of Laplace transforms. The solution is given in terms of Bessel-like functions. The limiting value of this solution is shown to agree with the steady-state solution. Numerical results illustrating the transient effects are for two typical cases     

̀Spatial impulse response of a rectangular double curved transducer

Calculation of the pressure field from transducers with both a convex and a concave surface geometry is a complicated assignment that often is accomplished by subdividing the transducer surface into smaller flat elements of which the spatial impulse response is known. This method is often applied to curved transducers because an analytical solution is unknown. In this work a semi-analytical algorithm for the exact solution to a first order in diffraction effect of the spatial impulse response of rectangular-shaped double curved transducers is presented. The solution and an approximation to it are investigated. The approximation reformulates the solution to an analytically integrable expression, which is computationally efficient to solve. Simulation results are compared to FIELD II simulations. Calculating the response from 200 different points yields a mean error for the different approximations ranging from 0.03% to 0.8% relative to a numerical solution for the spatial impulse response. It is also shown that the presented algorithm gives consistent results with FIELD II for a linear flat, a linear focused, and a convex nonfocused element. The solution involved a three-point Taylor expansion and gave an accuracy of 0.01%.     

Professor wheeler and the crack of doom: Closed cosmologies in the 5-d Kaluza-Klein theory

We study the classical and the quantum structures of certain 5-d Kaluza-Klein cosmologies. These models were chosen because their 4-d restriction is a closed, radiation-dominated, homogeneous, isotropic cosmology in the usual sense. The extra (field) dimension is taken to be a circle. In these models the solution starts from a 5-d curvature singularity with infinite circumference for the circle and zero volume for the 3-space. It evolves in finite proper time to a solution with zero dimension for the extra field direction. In the 5-vacuum case this is not a curvature singularity, but is a singularity of the congruence describing the physics, and in particular, the solution cannot causally be extended to the future of this point. In the 5-vacuum case this event coincides with the maximum of expansion of the 5-space. In the 5-dust cases, this point is a real 5-d curvature singularity. By adjustment it can be made to occur before or after the maximum of 3-expansion. The solution stops at that instant, but the 4-cosmology revealsno pathology up to the crack of doom. The quantum behavior is identical in these respects to the classical one.     

On-line pH value measurement of solution on the removing support material process

Removing support material from rapid prototyping (RP) part fabricated by fused deposition modeling is essential once the physical model is completed. Removing the support material from RP parts efficiently is an important concern because the product life cycle is shorter than before. In this study, a new on-line optical measurement system was developed to measure the pH value of solution during removing support material from fused deposition molded parts. The pH value of the solution can be predicted directly from the obtained maximum peak intensity according to the linear regression equation. The maximum discrepancy can be controlled within 4.37%. The time saving in removing the support material from RP parts up to 70.3% can be obtained by means of using the on-line measuring system for measuring the pH value of solution and compensating the pH value of solution immediately during the removing support material process.     

Weighted least-squares finite elements based on particle imaging velocimetry data

The solution of the Navier–Stokes equations requires that data about the solution is available along the boundary. In some situations, such as particle imaging velocimetry, there is additional data available along a single plane within the domain, and there is a desire to also incorporate this data into the approximate solution of the Navier–Stokes equation. The question that we seek to answer in this paper is whether two-dimensional velocity data containing noise can be incorporated into a full three-dimensional solution of the Navier–Stokes equations in an appropriate and meaningful way. For addressing this problem, we examine the potential of least-squares finite element methods (LSFEM) because of their flexibility in the enforcement of various boundary conditions. Further, by weighting the boundary conditions in a manner that properly reflects the accuracy with which the boundary values are known, we develop the weighted LSFEM. The potential of weighted LSFEM is explored for three different test problems: the first uses randomly generated Gaussian noise to create artificial ‘experimental’ data in a controlled manner, and the second and third use particle imaging velocimetry data. In all test problems, weighted LSFEM produces accurate results even for cases where there is significant noise in the experimental data.     

Electromagnetic scattering from two parallel 2D targets arbitrarily located in a Gaussian beam

In this paper based on the equivalence principle and the reciprocity theorem, the scattered field up to second-order by two parallel 2D targets arbitrarily located in a Gaussian beam is considered. The first-order solution can easily be obtained by calculating the scattered field from isolated targets when illuminated by a Gaussian beam. However, because of the difficulty in formulating the couple scattering field, it is almost impossible to find an analytical solution for the second-order scattered field if the shapes of 2D targets are not canonical geometries. In order to overcome this problem, in this paper, the second-order solution is derived by using the technique based on the reciprocity theorem and the equivalence principle. Meanwhile, the relation between the secondary scattered field from target #1 and target {\#}2 is obtained. Specifically, the bi- and mono-static scattering of Gaussian beam by two parallel adjacent inhomogeneous plasma-coated conducting circular cylinders is calculated and the dependence of attenuation of the scattering width on the thickness of the coated layer, electron number density, collision frequency and radar frequency is discussed in detail.     

Free vibration analysis of continuous orthotropic bridge decks

While studies of the free vibration problem of single span bridge slabs have been undertaken by a number of authors, literature on continuous span orthotropic bridge slabs is rather scarce. Furthermore, general continuous bridge deck problems have been dealt with by approximate methods only for specific types of boundary conditions. In this paper an attempt is made to formulate a general analytical solution which would be applicable to all types of boundary conditions. The solution developed is discussed here with special reference to “bridge type” boundary conditions. The analysis is based on the ordinary theory of thin plates and is formulated for linearly elastic materials with isotropic or orthotropic properties. A Levy-type series solution is employed and the problem of free vibration analysis of continuous isotropic and orthotropic bridge slabs is solved by using the principle of superposition. The solution is tested for convergence by varying the number of terms in the solution and the convergence is found to be excellent. Results obtained for continuous isotropic bridge decks are compared with published solutions and close agreements are found. For orthotropic bridge decks a similar comparison was not possible because of a lack of published results in the technical literature.     

UV-Vis光谱法表征化学镀Ni-P合金镀液中活性配合物组成

在化学镀Ni P合金碱性镀液中 ,使用较强的配合剂来防止镍离子的水解沉淀 ,同时用氨 氯化铵缓冲体系来维持镀液的pH值。由于镍 氨配合物的配合常数相对较小 ,通常认为氨并不参与配合作用 ,可是实际的一些实验现象无法得到合理解释。Touhami等人提出了镍 柠檬酸一氨三元配合物的放电机理 ,却未能提供该三元配合物存在的证据。利用紫外可见光谱研究了柠檬酸 氯化铵碱性Ni P合金镀液中镍离子的配合物 ,结果表明除了镍 柠檬酸配合物的存在以外还有镍 柠檬酸 氨配合物的存在。在系统研究柠檬酸盐和氨两种配体对吸收光谱影响的基础上 ,推断得出该三元配合物为Ni(Ⅱ ) (C6 H5O3-7) (NH3) 3。     

Linearized Electro-Optical Modulation for Analog Radio over Fiber

Intermodulation distortion (IMD) in Analog Radio-over-Fiber (a-RoF) poses a severe limitation to achievable error-free transmission. In this work, an optical feed-forward linearization scheme is presented and compared to an electrical pre-distortion solution. Both techniques show identical performance for intermodulation compensation of neighboring frequencies. The former suits wideband multi-carrier transmission better because it does not present limited operational bandwidth. Proof-of-concept experiments for reducing intermodulation and distortions are offered. A 5-dB improvement in the Error Vector Magnitude (EVM) distortion floor level is achieved. Trade-off between compensating for second and third harmonics was verified. Results indicate the solution allows maximal exploitation in a-RoF capacity.