氢化物发生ICP-AES法同时测定纯净水中的砷和汞

本文建立了氢化物发生ICP－AES法同时测定纯净水中砷和汞的方法,检出限分别为As1.7ug/L-Hg0.1ug/L,方法精密度（RSD）为As 3.46%,Hg2.85%,回收率为As92%-110%,Hg90-113%。     

INHOMOGENEOUS WAVES IN ANISOTROPIC POROUS LAYER OVERLYING SOLID BEDROCK

The problem of propagation of inhomogeneous waves in anisotropic porous layered medium is studied using transfer matrix. Firstly, transfer matrix for an anisotropic porous layer is derived. Biot's poro-elastic theory is incorporated to model the acoustics of anisotropic porous layer. The interface between porous layer and elastic half-space is considered as imperfect and modified boundary conditions are applied for this more realistic situation. The theory of transfer matrix is used to derive the analytical expression for the surface impedance. Numerical computation of results is done for different degrees of bonding in the low as well as high-frequency range. In the first case, which is relevant to geophysical studies, the surface impedance is predicted for low-frequency range and surface impedance for second model is computed in high-frequency range. It is observed that loose bondedness is accompanied by the loss of energy at the interface. The technique of transfer matrix is utilized to compute the surface impedance in both cases. The role of surface impedance in seismological studies and in the study of composites is discussed.     

Quantum theory of transverse galvano-magnetic phenomena

A quantum theory of electrical conduction in crosfsed electric and magnetic fields is given for the limit of very weak scattering. A density matrix formulation of the problem is used, and an arbitrary scattering mechanism is considered. The theory is found to be completely equivalent to theories given earlier by and by and .

Formulae are given for the resistivity in the quantum limit for both longitudinal and transverse orientations of electric field, for degenerate and non-degenerate statistics, and for several different scattering mechanisms. The oscillatory conductivity is calculated for acoustical and ionized-impurity scattering mechanisms. Formulae obtained for the quantum transport effects are in disagreement with the formulae of and of . The discrepancy is attributed to unwarranted approximations in those authors' treatments of scattering.     

PMD统计模型的改进

对于PMD的研究,分段模型是较优的选择.原始模型经过数学推导, 可转化为迭代模型.转化后的模型物理意义明晰,在直观上便于看出PMD随光纤分段增加的累积过程,具有较强的移植性.理论分析指明了数值方法产生误差的缘由,给出了实用数值计算的迭代模式,对于PMD补偿具有指导意义,同时使计算变得简洁.     

Furry Picture for Quantum Electrodynamics with Pair-Creating External Field

In the paper the perturbation theory is constructed for QED, for which the interaction with the external pair-creating field is kept exactly. An explicit expression for the perturbation theory causal electron propagator is found. Special features of usage of the unitarity conditions for calculating the total probabilities of radiative processes in the case are discussed. Exact Green functions are introduced and the functional formulation is discussed. Perturbation theory for calculating the mean values of the Heisenberg operators, in particular, of the mean electromagnetic field is built in the case under consideration. Effective Lagrangian which generates the exact equation for the mean electromagnetic field is introduced. Functional representations for the generating functionals introduced in the paper are discussed.     

Numerical procedures for natural gas accurate thermodynamic properties calculation

Natural gas (NG) is a mixture of 21 elements and widely used in the industries and domestics. Knowledge of its thermodynamic properties is essential for designing appropriate process and equipments. In this study, the detailed numerical procedures for computing most thermodynamic properties of natural gas are discussed based on the AGA8 equation of state (EOS) and thermodynamics relationships. To validate the procedures, the numerical values are compared with available measured values. The validations show that the average absolute percent deviation (AAPD) for density calculations is 0.0831%, for heat capacity at the constant pressure is 0.87%, for heat capacity at the constant volume is 1.13%, for Joule-Thomson coefficient is 1.93%, for speed of sound is 0.133%, and for enthalpy is 1.06%. Furthermore, in this work, the new procedures are presented for computing the entropy and internal energy. Due to lack of experimental data for these properties, the validation is done for pure methane. The validation shows that AAPD is 0.078% and 0.0133% for internal energy and entropy, respectively.     

用对称的三聚物分子研究三组分纠缠和分子内能量动力学

为了建立纠缠与能量的联系, 研究了对称三聚物分子的不同初始态的量子纠缠动力学, 用共生度描述三组分纠缠,计算了三个振动模之间的相互作用能. 结果表明非简谐振动局域态的共生度与相互作用能是正关联占优,而简谐振动局域态的共生度与相互作用能是反关联占优.     

Unstable state dynamics: A systematic evaluation of the master equation

The master equation for diffusion in a bistable potential is evaluated systematically in terms of the small-noise parameter for the case where the system is initially at the unstable state. The expansion is valid for all times, that is in the initial and intermediate as well as in the final regime. The theory does not involve free fitting parameters and is easily generalized to more complicated processes.     

Optimisation of damping treatments based on big bang–big crunch and modal strain energy methods

A cost-effective methodology is needed in various applications in order to optimise damping treatments for structures. Although some methods appear to be applicable for structures with relatively simple geometries, it is still difficult to utilise them for general structures. This paper presents an efficient approach for optimisation of passive damping treatments that can be applied to general structures. First, an optimisation procedure based on big bang–big crunch optimisation method is introduced and its effectiveness for damping optimisation is evaluated. Then, a procedure based on modal strain energy method is presented for the prediction of modal damping levels for structures with damping treatments and its performance is assessed. After that, for validation purposes, the proposed optimisation methodology is used to maximise modal damping for a single mode of a structure whose optimised configurations are known for the individual modes. Finally, the performance of the proposed optimisation procedure is demonstrated for the maximisation of damping levels for multiple modes at the same time and the applicability of the approach for general structures with passive damping treatments is demonstrated.     

Sound waves in a liquid with polydisperse vapor–gas bubbles

A mathematical model is presented for the propagation of plane, spherical, and cylindrical sound waves in a liquid containing polydisperse vapor–gas bubbles with allowance for phase transitions. A system of integro-differential equations is constructed to describe perturbed motion of a two-phase mixture, and a dispersion relation is derived. An expression for equilibrium sound velocity is obtained for a gas–liquid or vapor–liquid mixture. The theoretical results agree well with the known experimental data. The dispersion curves obtained for the phase velocity and the attenuation coefficient in a mixture of water with vapor–gas bubbles are compared for various values of vapor concentration in the bubbles and various bubble distributions in size. The evolution of pressure pulses of plane and cylindrical waves is demonstrated for different values of the initial vapor concentration in bubbles. The calculated frequency dependence of the phase sound velocity in a mixture of water with vapor bubbles is compared with experimental data.     

An analytic study of the friedel criterion in disordered magnetic states in transition metals in the presence ofS-D hybridisation,using the cluster bethe lattice approach

In this paper we present a new theory for including both short range order and long range order simultaneously in the well known cluster Bethe lattice method for binary alloys. We have used this theory for obtaining the Friedel criterion for the appearance of magnetic moments in disordered states using the single band Hubbard model. This is followed by a study of this criterion in a two-bands-d hybridised Hubbard model, which is considered as a simulation of real transition metals. A new technique for solving this problem in the Bethe lattice network is presented, which yields an analytic solution for the critical correlation strength in the presence of hybridisation and short range order. It is found that in all cases hybridisation tends to diminish the tendency for magnetisation, which is in accord with physical expectations.     

On the theory of nonlinear response in a nonideal plasma

A theory of nonlinear response is developed for studying nonlinear phenomena and nonlinear transport processes in nonideal Coulomb systems. Temporal plasma echo and transformation of waves in a nonideal Coulomb system are studied on the basis of the theory of nonlinear response to mechanical perturbations. General constraints imposed on nonlinear response functions are considered, and the model for determining quadratic response functions is formulated. The conditions for the emergence of temporal plasma echo and wave transformation are determined. It is shown that these nonlinear effects in a nonideal plasma can be initiated by ultrashort field pulses. A theory of transport is developed for determining the Burnett transport properties of a nonideal multielement plasma. A procedure is proposed for comparing the phenomenological conservation equations for a charged continuous medium and equations of motion for the operators of corresponding dynamic variables. The Mori algorithm is used for deriving the equations of motion for operators of dynamic variables in the form of generalized Langevin equations. The linearized Burnett approximation is considered in detail. The properties of the matrices of coefficients of higher-order derivatives in the system of conservation equations in the linearized Burnett approximation, which are important for hydrodynamic applications, are discussed. Various versions of the theory of nonlinear response are compared.     

Monte-Carlo algorithm for line-by-line calculations of thermal radiation in multiple scattering layered atmospheres

An algorithm for calculations of the longwave radiation in cloudy and aerosol slab atmospheres is described. It is based on the line-by-line and Monte-Carlo methods and is suitable for accurate treatment of both the gaseous absorption and the particulate multiple scattering in any spectral regions; other published algorithms as accurate as this can only make calculations in narrow spectral regions. It is recommended that this algorithm is well suited for radiation code validations as well as for theoretical investigations of radiative transfer in clouds and aerosols and satellite signal simulations.     

New approach for obtaining the time-evolution law of a chaotic light field in a damping-gaining process

A new approach for studying the time-evolution law of a chaotic light field in a damping-gaining coexisting process is presented.The new differential equation for determining the parameter of the density operator ρ(t) is derived and the solution of f ’ for the damping and gaining processes are studied separately.Our approach is direct and the result is concise since it is not necessary for us to know the Kraus operators in advance.     

Routes to nonsequential double ionization

A method is proposed for the calculation of the S matrix for many-electron processes in intense-laser atom physics, in close analogy to the strong-field approximation for one-electron processes. Given a scenario of how some process evolves, corresponding approximations to the classical action are made which allow for the evaluation of the quantum-mechanical S matrix. The method is applied to the distribution of the total electronic momentum in nonsequential double ionization, and the results are compared to recent measurements. Good agreement is obtained for neon for a rescattering scenario. There is no comparable agreement for helium and argon, and possible alternative scenarios are discussed.     

热电子与聚变等离子体相互作用模拟计算的误差分析

对惯性约束聚变(ICF)实验条件下热电子辐照聚变等离子体（DD,DT）的射程岐离和散射进行了分析。结果表明,射程岐离和散射随射程增加近似呈直线增加;射程岐离和散射大小与等离子质量有一定关系。在单能热电子入射下,散射是计算结果误差的主要来源,误差在5%以下,绝对数在数十MA。入射束流的电子完全沉积在热斑中的聚焦角度,在边沿点火方式中,氘等离子体中为20.64,氘氚等离子体中为21.8;在中心加热方式中,氘等离子体中为16.36,氘氚等离子体中为17.6,在技术上相对易于实现。     

Fractional-order permanent magnet synchronous motor and its adaptive chaotic control

In this paper we investigate the chaotic behaviors of the fractional-order permanent magnet synchronous motor(PMSM).The necessary condition for the existence of chaos in the fractional-order PMSM is deduced.And an adaptivefeedback controller is developed based on the stability theory for fractional systems.The presented control scheme,which contains only one single state variable,is simple and flexible,and it is suitable both for design and for implementation in practice.Simulation is carried out to verify that the obtained scheme is efficient and robust against external interference for controlling the fractional-order PMSM system.     

易于硬件实现的遥感图像JPEG2000压缩编码

讨论了易于硬件实现的JPEG2000内嵌码块编码压缩系统方案，提出了一种针对遥感图像特点的基于比特平面加权的EBCOT算法。本文算法采用比特平面提升减少遥感图像压缩中小目标的丢失问题，比JPEG2000建议的视觉加权率失真斜率提升方法相比有更好的效果。实验证明算法完全继承了JPEG2000高客观质量、分辨率渐进性、好的抗误码性能等优良特性，同时降低了T1编码器的编码时间，有利于硬件的实现，在遥感图像压缩领域具有实用价值。