Approximations of the Scattering Phase Functions of Particles

基于异常衍射理论和修改 Rayleigh-Debye 近似，在衔接形式的一个身体上现实主义的模型被描述接近粒子的散布阶段功能。什么时候与准确方法相比，这里报导的衔接的技术提供合理近似给 Mie 在大量角度和尺寸参数上结果，并且它表明是的优点计算联盟者经济。另外，新阶段功能模型能实质上被扩大到另外的形状并且方便地在更复杂的散布和与放射的转移方程的答案有关的排放问题使用了。

Solution of the finite slab criticality problem using an alternative phase function with the second kind of Chebyshev polynomials

The critical size of a finite homogenous slab is investigated for one-speed neutrons using the alternative phase function(AG, Anli-Gungor) in place of the scattering function of the transport equation. First of all, the neutron angular flux expanded in terms of the Chebyshev polynomials of second kind(UN approximation) together with the AG phase function is applied to the transport equation to obtain a criticality condition for the system.Then, using various values of the scattering parameters, the numerical results for the critical half-thickness of the slab are calculated and they are tabulated in the tables together with the ones obtained from the conventional spherical harmonic(PN) method for comparison. They can be said to be in good accordance with each other.

SAR Imaging of Moving Target Based on Quadratic Phase Function

In this paper, a novel signal processing technique hasbeen developed to refocus moving targets image from their smeared responses in the Synthetic Aperture Radar (SAR) image according to the characteristics of the received signals for moving targets. Quadratic Phase Function is introduced to the parameters estimation for moving target echo and SAR imaging. Our method is available even under a low SNR environment and acquiring an exact SAR image of moving targets. The simulated results demonstrated the validity of the algorithm proposed.

Explanation of Relation between Wave Function and Probability Density Based on Quantum Mechanics in Phase Space

The main problem of quantum mechanics is to elucidate why the probability density is the modulus square of wave function. For the purpose of solving this problem, we explored the possibility of deducing the fundamental equation of quantum mechanics by starting with the probability density. To do so, it is necessary to formulate a new theory of quantum mechanics distinguished from the previous ones. Our investigation shows that it is possible to construct quantum mechanics in phase space as an alternative autonomous formulation and such a possibility enables us to study quantum mechanics by starting with the probability density rather than the wave function. This direction of research is contrary to configuration-space formulation of quantum mechanics starting with the wave function. Our work leads to a full understanding of the wave function as the both mathematically and physically sufficient representation of quantum-mechanical state which supplements information on quantum state given solely by the probability density with phase information on quantum state. The final result of our work is that quantum mechanics in phase space satisfactorily elucidates the relation between the wave function and the probability density by using the consistent procedure starting with the probability density, thus corroborating the ontological interpretation of the wave function and withdrawing a main assumption of quantum mechanics.

Acquiring non-parametric scattering phase function from a single image

Acquiring accurate scattering properties is important for rendering translucent materials. In particular, the phase function, which determines the distribution of scattering directions, plays a significant role in the appearance of a material. We propose a distinctive scattering theory that approximates the effect of single scattering to acquire the non-parametric phase function from a single image. Furthermore, in various experiments, we measured the phase functions from several real diluted media and rendered images of these materials to evaluate the effectiveness of our theory.

Phase spectrum estimation of the seismic wavelet based on a criterion function

Phase spectrum estimation of the seismic wavelet is an important issue in high-resolution seismic data processing and interpretation. On the basis of two patterns of constant-phase rotation and root transform for wavelet phase spectrum variation, we introduce six sparse criteria, including Lu's improved kurtosis criterion, the parsimony criterion, exponential transform criterion, Sech criterion, Cauchy criterion, and the modified Cauchy criterion, to phase spectrum estimation of the seismic wavelet, obtaining an equivalent effect to the kurtosis criterion. Through numerical experiments, we find that when the reflectivity is not a sparse sequence, the estimated phase spectrum of the seismic wavelet based on the criterion function will deviate from the true value. In order to eliminate the influence of non-sparse reflectivity series in a single trace, we apply the method to the multi-trace seismogram, improving the accuracy of seismic wavelet phase spectrum estimation.

Phase composition, transition and structure stability of functionally graded cemented carbide with dual phase structure

The phase composition, phase transition and phase structure transformation of the wire-cut section of functionally graded WC-Co cemented carbide with dual phase structure were investigated by XRD phase analysis. It is shown that the composition of η phase in the core zone is Co_3W_3C (M_6 C type). The structure of cobalt based solid solution binder phase is fcc type. At the cooling stage of the sintering process, the phase transition of η phase, i.e. M_6C→M_12C and the martensitic phase transition of the cobalt based solid solution binder phase, i.e. fcc→hcp are suppressed, which facilitates the strengthening of the alloy. Because the instantaneous temperature of the discharge channel is as high as 10 000 ℃ during the wire cutting process, the processed surface is oxidized. Nevertheless, the oxide layer thickness is in micro grade. In the oxide film, η phase is decomposed into W_2C and CoO, and cobalt based solid solution binder is selectively oxidized, while WC remains stable due to the existence of carbon containing liquid organic cutting medium.

Analysis of a phase synchronized functional network based on the rhythm of brain activities

Rhythm of brain activities represents oscillations of postsynaptic potentials in neocortex,therefore it can serve as an indicator of the brain activity state.In order to check the connectivity of brain rhythm,this paper develops a new method of constructing functional network based on phase synchronization.Electroencephalogram(EEG) data were collected while subjects looking at a green cross in two states,performing an attention task and relaxing with eyes-open.The EEG from these two states was filtered by three band-pass filters to obtain signals of theta(4-7 Hz),alpha(8-13 Hz) and beta(14-30 Hz) bands.Mean resultant length was used to estimate strength of phase synchronization in three bands to construct networks of both states,and mean degree K and cluster coefficient C of networks were calculated as a function of threshold.The result shows higher cluster coefficient in the attention state than in the eyes-open state in all three bands,suggesting that cluster coefficient reflects brain state.In addition,an obvious fronto-parietal network is found in the attention state,which is a well-known attention network.These results indicate that attention modulates the fronto-parietal connectivity in different modes as compared with the eyes-open state.Taken together this method is an objective and important tool to study the properties of neural networks of brain rhythm.

Investigations of phase transition, elastic and thermodynamic properties of GaP by using the density functional theory

The phase transition of gallium phosphide (GaP) from zinc-blende (ZB) to a rocksalt (RS) structure is investigated by the plane-wave pseudopotential density functional theory (DFT). Lattice constant a 0 , elastic constants c ij , bulk modulus B 0 and the pressure derivative of bulk modulus B 0 are calculated. The results are in good agreement with numerous experimental and theoretical data. From the usual condition of equal enthalpies, the phase transition from the ZB to the RS structure occurs at 21.9 GPa, which is close to the experimental value of 22.0 GPa. The elastic properties of GaP with the ZB structure in a pressure range from 0 GPa to 21.9 GPa and those of the RS structure in a pressure range of pressures from 21.9 GPa to 40 GPa are obtained. According to the quasi-harmonic Debye model, in which the phononic effects are considered, the normalized volume V/V 0 , the Debye temperature θ, the heat capacity C v and the thermal expansion coefficient α are also discussed in a pressure range from 0 GPa to 40 GPa and a temperature range from 0 K to 1500 K.

Thermodynamic Functions and Phase Transformation of Metal Nanocrystals

A model to calculate the thermodynamic functions of the pure metal nanocrystals has been developed, with theconsideration of the effects of both the interfaces and the crystal in the nano-grain interior. As an example, theenthalpy, entropy and Gibbs free energy, as functions of the excess free volume at interfaces, temperature and grainsize, are calculated for the Co nanocrystals. Furthermore, the characteristics of phase transformationare studied, and the transformation temperatures at different levels of grain size, as well as the critical grain sizes atdifferent temperatures, are predicted. The calculation results show that, the nano-grained β-Co (fcc) is thermody-namically stable at temperatures much lower than that for the conventional coarse-grained materials, and may alsostably exist at room temperature when the grain size is reduced to be small enough. The present model is verifiedby comparisons between the experimental findings and the theoretical predictions.

The Wigner function and phase properties of superposition of two coherent states with the vacuum state

This paper discusses some statistical properties of the superposition of two coherent states with a vacuum state,such as sub-Poissonian photon statistics and negativity of the Wigner function.Phase probability distribution and phase variance are calculated.Special cases of the constructed superposition states are presented.The results show that depending on the vacuum state coefficient γ and the coherent state coefficient α,it can generate a variety of nonclassical states.

Solutions of Green's function for Lamb's problem of a two-phase saturated medium

The solutions of Green's function are significant for simplification of problem on a two-phase saturated medium.Using transformation of axisymmetric cylindrical coordinate and Sommerfeld's integral,superposition of the influence field on a free surface,authors obtained the solutions of a two-phase saturated medium subjected to a concentrated force on the semi-space.

Oscillatory integrals for phase functions having certain degenerate critical points

The paper is concerned with oscillatory integrals for phase functions having certain de- generate critical points. Under a finite type condition of phase functions we show the estimate of oscillatory integrals of the first kind. The decay of the oscillatory integral depends on indices of the finite type, the spatial dimension and the symbol.

Green's function solution for transient heat conduction in annular fin during solidification of phase change material

The Green's function method is applied for the transient temperature of an annular fin when a phase change material (PCM) solidifies on it. The solidification of the PCMs takes place in a cylindrical shell storage. The thickness of the solid PCM on the fin varies with time and is obtained by the Megerlin method. The models are found with the Bessel equation to form an analytical solution. Three different kinds of boundary conditions are investigated. The comparison between analytical and numerical solutions is given. The results demonstrate that the significant accuracy is obtained for the temperature distribution for the fin in all cases.

Deduction and Validation of an Eulerian-Eulerian Model for Turbulent Dilute Two-Phase Flows by Means of the Phase Indicator Function-Disperse Elements Probability Density Function

A statistical formalism overcoming some conceptual and practical difficulties arising in existing two-phase flow (2PHF) mathematical modelling has been applied to propose a model for dilute 2PHF turbulent flows.Phase interaction terms with a clear physical meaning enter the equations and the formalism provides some guidelines for the avoidance of closure assumptions or the rational approximation of these terms. Continuous phase averaged continuity, momentum, turbulent kinetic energy and turbulence dissipation rate equations have been rigorously and systematically obtained in a single step. These equations display a structure similar to that for single-phase flows.It is also assumed that dispersed phase dynamics is well described by a probability density function (pdf) equation and Eulerian continuity, momentum and fluctuating kinetic energy equations for the dispersed phase are deduced.An extension of the standard k-c turbulence model for the continuous phase is used. A gradient transport model is adopted for the dispersed phase fluctuating fluxes of momentum and kinetic energy at the non-colliding, large inertia limit. This model is then used to predict the behaviour of three axisymmetric turbulent jets of air laden with solid particles varying in size and concentration. Qualitative and quantitative numerical predictions compare reasonably well with the three different sets of experimental results, studying the influence of particle size, loading ratio and flow confinement velocity.

GREEN FUNCTION ON TWO-PHASE SATURATED MEDIUM BY CONCENTRATED FORCE IN TWO-DIMENSIONAL DISPLACEMENT FIELD

The Green function on two-phase saturated medium by concentrated force has a broad and important use in seismology, seismic engineering, soil mechanics, geophysics, dynamic foundation theory and so on. According to the Green function on two-phase saturated medium by concentrated force in three-dimentional displacement field obtained by Ding Bo-yang et al.,it gives out the Green function in two-dimensional displacement field by infinite integral method along x 3 direction derived by De Hoop and Manolis. The method adopted in the thesis is simpler.The result will be simplified to the boundary element method of dynamic problem.

Negativity of Wigner function and phase sensitivity of an SU(1,1) interferometer

Both the negativity of Wigner function and the phase sensitivity of an SU(1,1) interferometer are investigated in this paper. In the case that the even coherent state and squeezed vacuum state are input into the interferometer, the Heisenberg limit can be approached with parity detection. At the same time, the negativity volume of Wigner function of detection mode comes entirely from the input state and varies periodically with the encoding phase. In addition, the negativity volume of Wigner function is positively correlated with the phase sensitivity of the SU(1,1) interferometer. The positive correlation may mean that the non-classicality indicated by negative Wigner function is a kind of resource that can verify some related research results of phase estimation.

Unit 1 of Ling’ao Nuclear Power Plant phase II underwent hot functional test successfully

On February 25, the Unit 1 of Ling’ao Nuclear Power Plant phase II underwent a 41-day-long hot functional test successfully with its major systems satisfying the requirements for

A UNIVERSAL ANALYTIC POTENTIAL-ENERGY FUNCTION BASED ON A PHASE FACTOR

Using a field equation with a phase factor, a universal analytic potential-energy function applied to the interactions between diatoms or molecules is derived, and five kinds of potential curves of common shapes are obtained adjusting the phase factors. The linear thermal expansion coefficients and Young’s moduli of eleven kinds of face-centered cubic (fcc) metals - Al, Cu, Ag, etc. are calculated using the potential-energy function; the computational results are quite consistent with experimental values. Moreover, an analytic relation between the linear thermal expansion coefficients and Young’s moduli of fcc metals is given using the potential-energy function. Finally, the force constants of fifty-five kinds of diatomic moleculars with low excitation state are computed using this theory, and they are quite consistent with RKR (Rydberg-Klein-Rees) experimental values.

Wigner Function and Phase Probability Distribution of q-Analogue of Squeezed One-Photon State

在这篇论文，以在操作员的一个订的产品(IWOP ) 和使 q 变形的歼灭的逆的性质以内的集成的技术，挤压的一个光子状态的 normalizable q 类似物，它与一个相当不同由歌和扇子介绍了[Int。J。Theor。Phys。41 (2002 ) 695 ] ，被构造。而且， Wigner 功能和挤压的一个光子状态的 q 类似物的阶段概率分发被检验。