The core philosophy of Material Genome Initiative is transition of way of new material design from traditional "try-and-error" approach to in-silico material design approach where intensive computing and material informatics are employed. It aims to effectively speed up discovery, development, production and deployment of new material two times faster as it is now. It means a culture shift of new material discovery:simulation and prediction first, followed by experiment. An integrated computational material platform that can facilitate high-throughput quantum mechanical simulations and manage simulation lifecycle data is therefore vital. This paper depicts a high throughput computational material platform and software framework, namely, MatCloud, which effectively integrates individual quantum mechanical simulation tasks, data extraction and data storage into an automatic flow in an end-to-end manner without direct human control. Especially, core data curation activities are also integrated into this flow rather than happening at post-simulation stage separately. MatCloud is demonstrated in an example of disorder binary alloy design to be valid and effective.

Burton-Miller method, a complex linear combination of conventional boundary element method (CBIE) and hypersinglar boundary element method (HBIE), is widely used to deal with exterior acoustic problems. The difficult in implementing Burton-Miller method is computing strongly singular integrals (2D problems). Although, many weakly singular/regularization methods have been presented to evaluate these integrals, these methods are still difficult or extremely time consuming. In this paper, analytical integration of strongly singular boundary integral equations discretized with constant element for 2D Helmholtz problems is presented. All singular and strongly singular integrals are analytically evaluated in finite part sense as constant elements are applied to discretize boundary. Contour integral is used for singular and strongly integrals. Validity of formulas is demonstrated with numerical examples.

An isogeometric analysis based on a kind of local bivariate B-spline function and Burton-Miller method is introduced in boundary element method (BEM) for 3D Helmholtz problems.The method avoid efficiently computation of singular and nearly singular integrals aroud singular point of parametric surface.Numerical examples show that the algorithm has good performance in accuracy, efficiency and convergence.The algorithm performs isogeometric BEM (IBEM) with traditional global B-spline shape functions on CPU time and accuracy.The method has potential in engineering applications.

By introducing conductive burning process into classical deflagration-to-detonation transition (DDT) model, transition process from low speed conductive burning to convective burning to detonation was proposed. Transition process in HMX granular bed with 85% loading density was simulated. Development of conductive burning, convective burning and detonation was analyzed. In early stage combustion propagation rate is very slow. It propagates no more than 0. 2mm within 8. 16ms. After onset of convective burning, it tooks 20 ms to form a steady detonation with a velocity of 8 165 m·s^-1. Time to form detonation increases with decrease of particle diameter and ignition pressure.

With finite-differences approach,we investigate electronic properties of 2DEG in periodic magnetic field modulation. It shows that the system exhibits rich band structures with presence of magnetic field. Width of sub-bands becomes narrower as k_y increases,because the greater k_y is the deeper the potential well is. Due to different effective potential in two regions,k_y > 0 and k_y < 0,band structure in two areas are not consistent. More bound states are in the area of k_y > 0. In addition,we study effect on energy band structure of period,distance of magnetic stripes and strength of magnetization.

Du Fort-Frankel differential format for mode calculation of unstable resonator is presented.A fast finite differential method based on matrix motion and coordinate system transformation is used to calculate output field of a bare cavity and an active cavity.Calculated results are compared with references.It shows that the method is good both in precision and speed in calculating modes of an active unstable resonator with large Fresnel numbers.It can be 20 to 40 times faster compared with a conventional method.With this method,output power of a HF chemical laser is calculated.It shows that the output power increase with decrease of distance between gain medium and concave mirror.This result is valuable to the design of high power DF chemical laser.

Two-phase detonation of RDX particles suspended in air was numerically studied with CE/SE method.Behind leading shock front of detonation,explosive particles are accelerated and heated by the gas flow.Energy is released to support propagation of detonation wave.Dust detonation in a shock tube was numerically simulated.Distribution of physical quantity behind leading shock front was calculated.Parameters of detonation were obtained and they agree well with those in a reference.Dust detonation in a complex channel was numerically simulated.It shows that CE/SE method simulates gas-solid two-phase detonation successfully.

Threshold gain of laser mode in terahertz quantum cascade laser is calculated with finite element method. It shows that contact layer thickness and doping density have far greater impact on threshold gain than waveguide width and lasing wavelength. As thickness and density becoming smaller (greater), threshold gain of TM₁ (TM₀) mode becomes smaller. Far-field characteristics of the beam are analyzed using vector diffraction theory. The beam spot is basically elliptical. With increase of waveguide width or lasing wavelength, far-field divergence angles at x direction decrease or increase linearly. Though the contact layer thickness and doping density for TM₀ mode are different from that for TM₁, their far-field divergence angles at x direction are same. Moreover, far-field divergence angles at y direction are unaffected by waveguide width, and less affected by lasing wavelength. In terms of threshold gain and beam quality, TM₁ is more desirable than TM₀ mode.

Density reconstruction of inhomogeneous dense DT plasmas is studied with simultaneous iterative reconstruction technique(SIRT).In simulation of density diagnostics of a two-dimensional(2D) slice plasma,fast protons used fordiagnostics can be generated with laser-plasma interaction and energy loss of fast protons going through plasmas is crucial.As original and final energies of protons are given,density reconstruction by SIRT method is done without noise level of final energies.Accuracy of the method is better than that of the Tikhonov regularization method based on deviation principle of L-curve.In addition,the SIRT method is available with incomplete data.

The positive and negative frequency expressions of quasi-monochromatic optical fields of a pulse in fiber-optic communication and the positive and negative frequency forms of Fourier transformations and nonlinear Schrödinger(NLS) equations are discussed.Especially,in the solution of pulse spectrum,the negative frequency form of NLS equation should be solved by the negative frequency form of Fourier transformation,while the positive frequency form of NLS equation is solved by the positive frequency form of Fourier transformation.An example is given using split step Fourier method.

We introduce FD-BPM to three-dimensional waveguides and calculate the refractive index of Er³⁺-Yb³⁺ co-doped phosphate glass waveguides.The simulation for a signal light (1.54 μm) and a pump light (0.98 μm) is performed in a Er³⁺-Yb³⁺ co-doped phosphate glass waveguide with FD-BPM.It shows that the scatter loss can be neglected and the optical field is symmetric in a buried waveguide.A buried Er³⁺-Yb³⁺ co-doped phosphate glass waveguide is demonostrated the best to make Er³⁺-Yb³⁺ co-doped phosphate glass waveguide lasers and amplifiers.

A fast simulation annealing (SA) algorithm for the design of diffractive optical elements (DOE) for uniform illumination is presented.The Tsallis statistic and corresponding utility function are introduced into a hybrid algorithm in which the self-iterative and SA algorithms are combined to enhance the efficiency.Compared with traditional SA algorithm,simulated results show that it saves 99% of time to converge the incident energy into a desired region with the same mean square error (MSE).

Ion bombardment affects the stability and lifetime of micro-tip field emission devices. In the Si field emission array (FEA), the atoms in the residual gas may collide with electrons and be ionized, so many ions could be produced. Due to the electrical field in the FEA device, the ions bombard on the Si tips. This paper analyzes the mechanism of ion bombardment on the Si tip. The process concerning ion generation and ion bombardment is numerically simulated. The damage to the tip is analyzed quantitatively, and related conclusions are given.

A 9-bits lattice gas model with temperature effect is applied into the simulation of thermoacoustic prime movers. The self-excited oscillation in a thermoacoustic resonant tube has been simulated. The distribution of two-dimensional temperature field and the evolution process of temperature are presented as well. The effects of the length of stack and of its position on acoustic pressure have also been investigated numerically. The simulation results are valuable to the optimum design of stack. The validity of the lattice gas model for a thermoacoustic engine has been verified by the comparison of the simulated and experimental results, which demonstrates that the lattice gas method is suitable for the thermoacoustic simulation.

Relationships between the choice of the positive and negative frequency expression of optical waves, adoption of Fourier transformation form and form of nonlinear Schrödinger equation are discussed. The generally accepted form of nonlinear Schrödinger equation is the result of choosing the negative frequency expression. In accord with the negative frequency expression, the form of Fourier transformation cannot be chosen at will. When the nonlinear Schrödinger equation is solved using numerical methods based on Fourier transformation, the form of fast Fourier transformation must be paid attention in the programming languages used. In most programming languages, the adopted forms of fast Fourier transformation and inverse transformation are opposite to the forms adopted in nonlinear optics. It is also pointed out that some related numerical errors existed in some references.

Based on many body potential model,the crystallizing processes of Au and Ag are investigated by means of molecular dynamics simulation technique.The pairs analysis method is applied to compare the difference of the local symmetry of molecular cluster between both atoms.In the process of crystallization, the rebuild of the local cluster and the transformation of pairs is found to be from 1661、1441 to 1421、1422.The other important information given is about the microstructure of Au,Ag.

A volume weighting CIC method is developed to compute the node charges and currents in PIC simulation of axial symmetrical plasmas.A set of formulae for computing the node charges and currents is derived.The results given here can be applied to 2(1/2) dimensional electrostatic and electromagnetic PIC simulation of axial symmetrical plasmas.

A Practical Monte Carlo Sampling Library is described. The library provides pesudorandom number generators using the best algorithms, excellent random variable generators of many important probability distributions such as spatial position, energy and motion direction distributions often used in particle transport problems. In addition a special test system for sampling library is designed and applied. The library runs on PC/386 (486). Its installation and usage are very easy. It can be applied in various fields and easy portable.

Some successful applications of MCNP code are introduced for the nuclear critical safety, techneque research for nuclear safeguards, and neutron slowing-down install simulation. Developments of this code for these applications are desovibed. A brief discussion is made about necessary development for future applications as well.

The present paper discribes the general techniques for the Monte Carlo simulation of the master equation. The Monte Carlo simulation is considered for the difference solution of the master equation under the condition of the general transition rate form. The integral equation with a transient source term is established, which is equivalent to the master equation initial problem. Thus, the more general techniques are presented for the simulation of the master equation.

The Monte Carlo Method has been applied to study the properties of the ground state of the four nucleon system. The wave function of the nucleon is assumed to contain the Jastrow factor, which Is due to the correlation of the other nucleons in the system. The variational constants of the wave function have been calculated by Zabolitzky and Kalos.Jn this article, we have used the wave function quoted above to calculate the binding energy of the system, its root mean square radius, the density distribution of the nucleon and the form factor.The result of our calculation indicates that the Monte Carlo Method can be used to study the properties of the ground state of the nuclear system. It requires to do further work to ensure that this method can be used to study other properties of the nucleus such as the properties of the excited states, the nuclear transitions, etc.