Comparison of the solutions from a novel variational method with numerical results for the study of beam propagation in a Kerr medium with nonlinear absorption

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.     

Comparative experimental study on absolute measurement of spherical surface with two-sphere method

The two-sphere method with multiple confocal measurements and a “cat's-eye” measurement is used widely in high accuracy interferometry, which can obtain the absolute surface data of the tested spherical surface. We provide a comparative experimental study on absolute testing procedures for spherical surface with two-sphere method, which include the classical Jensen method with three position measurements, the Zygo method with five position measurements and a variant of the Jensen method. The variant of the Jensen method can combine the multiple “three-position” measurements based on the fiducial method and averaging method. The repeatability of the involved absolute measurement methods is also studied by the five set experiments, and the corresponding Zernike fitting coefficients are compared in detail. The experimental results are meaningful for implementation of two-sphere method with higher repeatability in practice.     

An application of a transcorrelated procedure to the calculation of the energy of the hydrogen molecule

The ground-state energy of the hydrogen molecule is calculated using both the standard variational method and a new transcorrelated method. The value obtained with the new method compares favourably with that obtained by the standard method. If the method used in this paper can be extended to more complicated systems, it is expected that it will enable more accurate energies to be calculated for these systems than is possible using the standard variational method.     

Calculation of Phase Diagram of Lattice SU(3) Mixed Model

The variational-cumulant expansion method has been extended to SU(3) mixed-action lattice gauge theories. By using the method, the phase diagrams of SU(3) mixed model are obtained in four and five dimensions. The results are in good agreement with the Monte Carlo results. The comparison with results of the mean field method and the mean plaquette method is abo given.     

紫外成像告警系统信噪比的研究

对紫外告警系统成像子系统的信噪比进行了研究与分析,应用一种新的根据ICCD紫外成像系统采集的图像进行计算信噪比的方法,该方法解决了常用信噪比测试方法中待测参数多,采用测试仪器多,带来的误差较大等问题。根据该方法所搭建的实验系统不仅实现了数据的快速处理,还使观察者能够直观地看到被测目标的动态图像,同时也可以利用该方法系统地分析紫外告警成像子系统的不同情况下的噪声的特性。     

Scattering of light by axially symmetric particles: Modification of the point-matching method

The approach based on the separation of the fields into two parts with definite properties and the proper choice of special scalar potentials for each of them is applied to the point-matching method. Earlier, such a procedure carried out within the framework of the method of separation of variables for spheroids allowed us to obtain a solution that is considerably more efficient for strongly prolate and strongly oblate particles than solutions obtained with other versions of this method. It was found that the replacement of the summation over points on the particle surface in the point-matching method by the corresponding integral leads to a faster and more exact algorithm. The applicability of the proposed method is considered in comparison with the related method of extended boundary conditions. For spheroids and Chebyshev particles with a maximum-to-minimum-size ratio exceeding 1.5–2, the efficiency of the point-matching method is not high. For other Chebyshev particles, the point-matching method is undoubtedly preferable to the commonly used method of extended boundary conditions since it allows one to increase the accuracy of calculations by several orders of magnitude. Moreover, whereas the latter method is in principle inapplicable to certain Chebyshev particles, the former lacks this disadvantage.     

The finite difference time domain calculation of one-dimensional photonic crystals composed of repetitive metallic and dielectric layers

The frequency dependence on the reflectance of a one-dimensional (1D) photonic crystal composed of repetitive metallic and dielectric layers was simulated by the finite difference in the time domain (FDTD) method, and with results compared to the conventional transfer matrix (TM) method. The simulation from the FDTD method with an impedance-matched boundary of finite dimensions yields results similar to the calculation from the TM method with unbounded planes. The FDTD method is prominent in dealing with films of finite area including defects at some locations. The reflectivity increases and the rejection bandwidth decreases as the number of layers increases. PACS 42.70.Qs; 47.11.Bc; 78.20.-e; 78.67.-n     

HL-RBWO-冷腔特性的一种快速算法

 在传统谐振法基础上发展了一种计算慢性结构（SWS）冷腔参数的脉冲响应法，它的主要思想是利用有丰富谐波成分的窄脉冲作为激励源来代替实验系统中的扫频源，从而使得获取RBWO的色散曲线速度大大加快。这种方法使得脉冲响应法成为计算SWS冷腔参数的一种快速数值算法，更加适合于数值计算，并在研究HL-RBWO时得到有效的应用。     

Vibro-acoustic analysis of complex systems

A general method is presented for predicting the ensemble average steady-state response of complex vibro-acoustic systems that contain subsystems with uncertain, or random, properties. The method combines deterministic and statistical techniques to produce a non-iterative hybrid method that incorporates equations of dynamic equilibrium and power balance. The method is derived explicitly without reference to statistical energy analysis (SEA); however, it is seen that the wave approach to SEA can be viewed as a special case of the proposed method. The proposed method provides a flexible way to account for necessary deterministic details in a vibro-acoustic analysis without requiring that an entire system be modeled deterministically. The method therefore provides a potential solution to the mid-frequency problem (in which a system is neither entirely deterministic nor entirely statistical). The application of the method is illustrated with a numerical validation example.     

Receptances of non-proportionally and continuously damped plates—Reduced dampers method

This paper presents a method for the dynamic analysis of continuously and non-proportionally damped plates in bending modes. The damping can be in the form of constrained or unconstrained layers. The method is an extension of the equivalent dampers method discussed in a previous paper, in which the damping matrix of a discretized plate is replaced by a diagonal equivalent damping matrix. Each diagonal element represents an equivalent damper inserted between the structure and ground. In this method the number of equivalent dampers is reduced so that the receptance matrix of the damped structure can be obtained economically by a direct matrix method. The receptances of two different partially coated plates in transverse directions are computed by the method suggested. The verification of the results is demonstrated by comparison with the experimental values and also with the theoretical values obtained by the equivalent dampers method. The method presented can also be applied to the transverse vibration analysis of plates with discrete damping inserts.     

定向耦合法测量非标准接口元件驻波系数

 利用网络分析仪,根据需要在设定的频率范围进行扫频测量,网络分析仪的端口1输出的微波信号经过微波传输转换器进入与待测非标准元件匹配连接的连接段（如波导）;网络分析仪的端口2连接定向耦合器,用于监测传输段内的反射微波信号。首先,在非标准接口端面连接短路面,通过网络分析仪测量反射信号在设定频点的相对幅度值;然后去掉短路面,在非标准接口端面连接待测元件,再次测量反射信号在特定频点的相对幅度值;最后根据本文推导的公式得出驻波系数。该方法的测量误差与定向耦合器的方向性（方向性系数越大越好）和待测元件驻波系数有关。将该方法运用在非标准接口匹配负载驻波系数的测量中,定向耦合器方向性系数取为40 dB,测得其驻波系数小于1.2,误差小于20%。该方法简便可行,可以用于测量常用的非标准接口元件尤其是非标准低驻波系数元件的驻波系数。     

Enhancement of efficiency of vibration suppression using piezoelectric elements and LR circuit by amplification of electrical resonance

This paper describes a vibration suppression method based on passive vibration suppression using a piezoelectric element and an LR circuit. The proposed method applies a voltage that is proportional to the displacement or acceleration of the host structure to the LR circuit in series. Because the applied voltage equivalently increases the voltage generated by the piezoelectric effect in the piezoelectric element, the effect of the vibration suppression is increased with an increase in the applied voltage. The proposed method is categorized as a hybrid vibration suppression method that involves only an analog circuit. The governing equations were formulated, and the optimum values of the inductance and resistance were theoretically derived using the two fixed point method as well as the passive method. The characteristic features of the proposed method were theoretically investigated by comparing the added stiffness and damping, amount of the applied voltage, and time-averaged power of the applied voltage with those of the conventional methods. In addition, the stability of the proposed method was theoretically analyzed. The effectiveness of the proposed method and the theoretical analysis were verified through experiments.     

连续流动分析法测定土壤中的有效磷

为了提高土壤中有效磷的检测效率和方法的稳定性,研究了现代仪器分析方法-连续流动法测定土壤中有效磷的含量,对连续流动法与农业部标准方法NY/T 148-1990《石灰性土壤有效磷测定方法》、NY/T 1121.7-2006《酸性土壤有效磷的测定》的测定结果进行配对两处理t检验,结果表明：连续流动法与标准方法检测的结果不存在系统误差,样品测定的相对标准偏差均小于10％,连续流动法测定值的相对标准偏差较标准方法略小.同时,用连续流动法对土壤标准样品GBW 07413-GBW 07414（碱法）、GBW07416-GBW 07417（酸法）进行有效磷的测定,测定值与标准值相吻合.     

烟用有机肥中氯离子含量测定方法的比较

为科学指导烟草栽培中有机肥的施用,以保证烟叶氯含量在适宜范围内,保障烟叶质量,研究比较了离子色谱法、连续流动分析法、硝酸银滴定法和佛尔哈德法测定烟用有机肥中氯离子含量.几种测定氯离子含量的方法比较结果为:离子色谱法和连续流动分析法测定烟用有机肥中氯离子含量的结果均较好,且方法不存在显著差异;硝酸银滴定法对低含量样品的检测偏差较大;佛尔哈德法不适宜用于测定烟用有机肥中氯离子含量.离子色谱法和连续流动分析法的平均回收率分别为102.4％、103.1％,方法检出限分别为0.05mg/L、0.30mg/L,对样品测定的平均相对标准偏差分别为2.41％和2.77％.     

驻波法测超声波衰减系数

用驻波法测量超声波在空气中衰减系数的实验方法。与前人的方法进行比较。新的测量结果更符合实际。只有当换能器反射系数r〈0.619时,用简单波拟合得到的衰减系数才比较可信。同时讨论了该方法的实用意义。     

Analysis of force characteristics of a superconducting ball in a given magnetic field

The electromagnetic force characteristics along Z direction of a superconducting ball levitated by spherical coils with shaping blocks are calculated based on a semi-analytical method. The calculating results from the semi-analytical method are compared with the finite element analysis (FEA) method through a calculation example. The method can be applied to further analysis of dynamic characteristics and parameter optimization in the suspension system.     

非线性偏最小二乘导数分光光度法同时测定复方新诺明中二组分的含量

构造了导数光谱与多组分浓度间的非线性模型 ,以偏最小二乘法估计模型参数 ,建立了同时测定两组分的非线性偏最小二乘导数分光光度法 ,方法用于复方新诺明中磺胺甲唑SMZ(Sulfamethoxazole)和甲氧苄啶TMP(Trimethoprim)含量的测定 ,10份模拟样中SMZ ,TMP的回收率分别为 99 8%和 10 0 1% ,RSD分别为 1 3%和 1 6 %。结果明显好于线性偏最小二乘导数分光光度法。用该法测定复方新诺明片中的二组分含量测定结果与药典方法一致 ,该法为复方制剂的分光光度分析提供了更为理想的新途径。     

雷诺校正法在煤发热量测定中的应用

介绍雷诺校正法计算煤发热量的原理、算法及应用.方法应用于燃煤发热量计算,结果表明,用雷诺校正法处理煤发热量测定时,其结果优于瑞方公式法和奔特公式法,与国标法相比,分析误差在规定范围内.在文中列出了雷诺校正法处理煤发热量的实用Matlab源程序.     

一种新型的多包层光子晶体光纤的分析方法

传统有效折射率方法只能模拟具有相同空气孔大小的单包层光子晶体光纤.针对这一问题,提出了一种改进的有效折射率法,能够计算具有不同孔径的多包层光子晶体光纤的传输特性.并用此方法对三包层光子晶体光纤的基模有效折射率和色散等特性进行了数值模拟,结果与多极法模拟出的结果符合得很好.这种改进的有效折射率法拓展了传统有效折射率法的适用范围,对快速准确地分析和设计具有不同传输特性的多包层光子晶体光纤提供了理论依据. 关键词： 光子晶体光纤 多包层 有效折射率方法 色散     

Determination of Spatial Distribution of Plasma Electrons by Multibeam FIR Interferometry

The spatial distribution of plasma electrons in the ISX-B Tokamak has been determined by Abel-inverting vertical integral data from far infrared (FIR) laser-phase shift measurements. The calculational method for performing the Abel inversion is discussed and the results of the inversion of several sets of data are compared with Thomson scattering measurements of the pointwise electron density, and with the 2-mm interferometer measurement of the horizontal-midplane line-integral electron density. The inversion method used is essentially that described by Demas et al. This method is an extension of the method described by Yasutomo et al. The main difference is that the inversion method used here can treat plasmas with any outer boundary shape as long as the radius of the surface is single valued. In this regard it is more general than the inversion method of Wetzer, which is restricted to using an elliptical outer-plasma boundary.