Advanced Materials Research Vol. 813

Abstract: 50101 working face roof is typical compound roof in Guantun coal mine. Gateway design uses anchor-net + anchor rope supporting method. Sinking large roof abscission layer,the maximum abscission reached 450 ~ 500 mm Within one month after the construction .Anchor cable faults is frequently. In order to solve the above problem, We proposed to anchor cable φ15.24 mm changed toφ21.60 cable and Mining steel i-beam changed to W steel band . We can improve the support strength of anchor cable. With new support mode, We successfully make the roof abscission layer of subsidence and anchor cable fracture rate decline .

Abstract: The rapid development of land resources and the sharp growth in demand for land have resulted in land degradation. Therefore, the reclamation, planning and management of such areas, including plans for implementing corresponding measures, are a very important topic at present. Located in the Yangmingshan National Park, the Dayoukeng disused mining area has craters created by volcanic activities and hot springs, and it was once the mining centerpiece of Taiwan. In addition to related literature review and field investigation as well as discussions on the operational procedures of ecological planning methods, this research carried out studies on landscape reclamation cases at home and abroad. Afterward, this research analyzed the land fitness of the Dayoukeng area based on landscape conservation principles. Finally, according to the analysis results, this research proposed land reuse planning principles and concept planning for the landscape reclamation and reuse. Meanwhile, the author expects to build up the experience of this case's research to serve as a reference to the reuse planning of disused mining areas in the future.

Abstract: The composition, the texture and structure, the mineralogical characteristics of major minerals, the main occurrences of major elements and the distribution rules of vanadium titanium magnetite of Hongge area, Panzhihua, Sichuan Province of China, were studied in details by the methods of chemical multi-elements analysis, optical microscope, scanning electron microscope (SEM), electron probe micro-analysis (EPMA), X-ray diffraction (XRD) and X-ray fluorescence (XRF). The study results provide references to the vanadium titanium magnetite beneficiation process of this mining area.

Abstract: In this paper the effects of Ca²⁺ and Mg²⁺ on the floatability of smithsonite and hemimorphite were investigated through microflotation. The flotation tests were performed using purified samples from Lanping mine of China by the microflotation technique. The Ca²⁺ flotation results showed that the recovery of smithsonite decreased from 89.81% to 83.92% and the recovery of hemimorphite decreased from 84.83% to 76.03% when increasing Ca²⁺ concentration from 200mg/L to 1000mg/L. Also, while increasing Mg²⁺ concentration from 200mg/L to 1000mg/L the smithsonite and hemimorphite recoveries declined to reach 80.03% and 71.75%, respectively. It can be concluded that the recoveries of smithsonite and hemimorphite showed a decreasing trend with the increasing of Ca²⁺ and Mg²⁺ concentration, and the effect on the recovery of hemimorphite was larger. Moreover, the effects of Mg²⁺ on the smithsonite and hemimorphite are greater in the same test condition, which could be attributed to the solubility product difference of Ca (OH)₂and Mg (OH)₂.

Abstract: Using the typical gas extraction from high gas coal seam group Songzi Moutain mine as example, to give the basic parameters of coal seam, and elaborate the measures and design process of gas extraction from coal seam group to provide a referential engineering case for other gas mines with similar conditions.

Abstract: This work used Monte Carlo simulation to investigate the effect of lattice strain on critical temperature of the ferromagnetic Ising ultra-thin-film. Using Bethe-Slater interpretation, exchange interaction was assumed Lennard-Jones (LJ) potential function, and becomes functions of interatomic distance. The cluster flip algorithm was used to update the spin configuration, where energy and magnetization were measure to extract critical temperature via the fourth order cumulant of the magnetization. Results show that initial interatomic distance and strain have strong effect on magnetic critical point behavior. The critical point can be enhanced or suppressed depending on how exchange interaction is modified by the values of initial interatomic distance and strain. A scaling function in predicting critical temperatures is also given in this work. Results agree well with previous applicable works, which confirms the reliability of the reported results.

Abstract: This work studies the temperature-driven ferroelectric phase transition of ferroelectric polarization under the absence of electric field. The modified Heisenberg model in three dimensions was considered and simulated via Monte Carlo simulation. The Metropolis algorithm and the periodic boundary condition were employed. The dependence of electric polarization on temperature was investigated to define the ferroelectric phases and their structural phase transitions. From the results, with well-defined set of relevant temperature parameters, the phase dependent polarization-behavior was found with a sudden change in its behaviors at the transition points. The structure factors were also considered and supported these phase changes. This conclusively pinpointed the important of temperature-dependent parameters in modeling ferroelectric materials.

Abstract: Within the frame of average spin model the calculation of dependence of critical phase transition temperature in antiferromagnetic ultrathin films of different crystalline structure on their thickness has been carried out. I has been shown, that relative change of Neel temperature is subject to power law with exponent close to the experimental values.

Abstract: Nanostuctured Tb³⁺-doped Gd₂0₃ particles were synthesized from chloride precursors GdCl₃ and TbCl₃ by NaOH addition in a polyol medium. Then, Gd₂0₃: Tb³⁺ particles were encapsulated in a polysioxane shell by being immersed in a mixed solution of APTES and TEOS. Effect of NaOH quantity on size and luminescent property of obtained core-shell nanoparticles was studied. The result shows that the size of nanoparticles increased with the increase of NaOH quantity from 30% to100% of stoichiometry. The emission intensity of core-shell nanoparticles increased with the size of particles due to the enhancement of energy transfer between core and shell.

Abstract: The electronic and the superconducting properties of Pd were studied in the framework of density functional perturbation theory. We explored the superconducting transition temperature for bulk Pd and predicted possible superconductivity at ambient and high pressures. It is found that of Pd is 0.0356 K at ambient pressure and it decreases with pressure.