Calculation of Excess Stability Functions of Four Binary Alloys

The thermodynamic model based on cluster of two atoms is considered with the view to obtaining Scc(0) and the excess stability function of Scc(0). Concentration-concentration fluctuation; Scc(0) of four binary molten alloys was calculated. The thermodynamic properties of these alloys are evaluated based on cluster of two atoms (A & B) or (B & A). Each system has the view of obtaining concentration-concentration fluctuation; Scc(0) enumerating the low-order atomic correlation in the nearest neighbour shell of liquid binary alloys.The highlights of excess stability functions(ES) of Scc(0) of these alloys were reported. The values of Scc(0) for all these alloys are higher than the ideal solution values. The values of Scc(0) for Bi-Cd alloy is close to the ideal Scc (0). The indication of the excess stability of Scc(0) for some alloys is in support of homocoordination. The Scc(0) and excess stability function of Scc (0) for the four alloys are presented. Keywords: Concentration-concentration fluctuation, Excess stability function, Ordering energy.

An Accurate Sparse Recovery Algorithm for Range-Angle Localization of Targets via Double-Pulse FDA-MIMO Radar

In this paper, a sparse recovery algorithm based on a double-pulse FDA-MIMO radar is proposed to jointly extract the angle and range estimates of targets. Firstly, the angle estimates of targets are calculated by transmitting a pulse with a zero frequency increment and employing the improved l 1 -SVD method. Subsequently, the range estimates of targets are achieved by utilizing a pulse with a nonzero frequency increment. Specifically, after obtaining the angle estimates of targets, we perform dimensionality reduction processing on the overcomplete dictionary to achieve the automatically paired range and angle in range estimation. Grid partition will bring a heavy computational burden. Therefore, we adopt an iterative grid refinement method to alleviate the above limitation on parameter estimation and propose a new iteration criterion to improve the error between real parameters and their estimates to get a trade-off between the high-precision grid and the atomic correlation. Finally, the proposed algorithm is evaluated by providing the results of the Cramér-Rao lower bound (CRLB) and numerical root mean square error (RMSE).

Crystalline to amorphous transformation in solid-solution alloy nanoparticles induced by boron doping

Synthesis of Pd–Ru–B solid-solution alloy is first reported. Alloying of B atoms into Pd–Ru alloy is accompanied by a characteristic crystalline–amorphous transformation to results in the disappearance of long-range atomic correlation.

NXFit: a program for simultaneously fitting X-ray and neutron diffraction pair-distribution functions to provide optimized structural parameters

NXFitis a program for obtaining optimized structural parameters from amorphous materials by simultaneously fitting X-ray and neutron pair-distribution functions. Partial correlation functions are generated inQspace, summed and Fourier transformed for comparison with the experimental data inrspace.NXFituses the Nelder–Mead method to vary a set of `best guess' parameters to achieve a fit to experimentally derived data. The output parameters fromNXFitare coordination number, atomic separation and disorder parameter for each atomic correlation used in the fitting process. The use ofNXFithas been demonstrated by fitting both X-ray and neutron diffraction data from two quite different amorphous materials: a melt-quenched (Na2O)0.5(P2O5)0.5glass and a (TiO2)0.18(SiO2)0.82sol–gel.

Cini-Sawatzky's Model in Studies of Electrodeposited Ni-Mo Alloys with Polymers

Electronic structures of electrodeposited Ni-Mo layers with polyethylene, polytiophene and polypyrrole were studied by Auger electron spectroscopy using the Cini-Sawatzky's model. Comparison of the theoretical and experimental lines was carried out using the asymmetry parameter of the spectral lines. It is pointed out that the changes of the spectral main lines Ni and Mo are connected with the ways of polymerization. It has been also shown that the application of the Cini-Sawaztky model to the experimental spectral lines can be used to explain the distortion appearing in the materials. Model parameters, i.e., intra-atomic correlation and bandwidth were determined.