Xuzhou Institute of Technology

About: Xuzhou Institute of Technology is a education organization based out in Xuzhou, China. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 1696 authors who have published 1521 publications receiving 13541 citations.

Coal-and-Gas Outburst Forecast Using CCPSO and SVM

Abstract: In order to forecast effectively coal-and-gas outburst in coal-mine,a new method for coal-and-gas outburst forecast based on CCPSO(complete chaotic particle swarm optimization) and SVM(support vector machine) was pre-sented.With multi-fractal dimension spectrum of gas emission amount dynamic time series in the front of work-face in coal-mine being feature index,the forecasting model was constructed by using SVM.The parameters vector of the proposed model was selected and optimized by CCPSO and the criteria of CERM(classification error rate minimization) and TSSM(test sample set minimization).The experimental results show that the proposed method is effective and provides a new approach for forecasting coal-and-gas outburst in coal-mine.

Heat Treatment Technology and Property Study on 40Cr of Shearer Picks Body

Abstract: Cutting tooth especially due to the poor quality of the shearer brazing, caused enormous economic losses each year in our country, which caused great pick consumption and delayed hours, and then resulting in reduced efficiency. The tooth body wear of the whole shearer picks accounts for half of its overall failure. In this experiment, the heat treatment which included heating temperature, soaking time, and cooling, etc. was designed by service conditions and performance requirements of the body material 40Cr. The change of microstrcture and mechanical property was analysed by quenching and tempering treatment, thus prolong the service life of shearer picks by improving the comprehensive performance of the tooth body material.

Development of Shearer Picks Brazed by Copper Brazing Agent and Property Study on Brazing

Abstract: As wearing parts, shearer picks, in which the huge consumption and inefficient are caused by the poor quality of brazing, are widely used in the mining process In this paper, the cemented carbide YG15, 42CrMo steel and HL105 copper brazing film were used as the head, body and solder, respectively, and the furnace brazing was used for shearer picks where the home-made water-soluble copper brazing agent was fabricated instead of the traditional dehydrated borax The results show that the strength of the welded joint improves greatly and is up to a superior level When the copper brazing agent and water in a four-to-six ratio, the solder is completely wetted, the best bending resistance of the head is obtained, the brazing seam of picks which are superior to the factory production is brimming, and thus the service life is significantly improved

Transition rates, branching ratio, and lifetime of the 2 p 3 3 s S 2 ∘ 5 metastable state in O I

Abstract: Based on the multiconfiguration Dirac-Hartree-Fock method, the accurate line strengths, transition rates, branching ratio, branching fraction, and lifetime of the $2{p}^{3}3s\phantom{\rule{0.16em}{0ex}}^{5}S_{2}^{\ensuremath{\circ}}$ metastable state of neutral oxygen atom (O i), together with the uncertainties evaluated from the residual electron correlation effects, are determined by taking into account the effects of core-core, core-valence, and valence correlations, the Breit interaction, and QED effect. It is shown that the core correlation effect has a certain influence if the separation between $^{3}S^{\ensuremath{\circ}}$ and $^{5}S^{\ensuremath{\circ}}$ in the ${p}^{3}s$ configuration is accurately calculated. It is found that the calculations of branching ratio of $^{5}S_{2}^{\ensuremath{\circ}}$ remain stable in different electron correlation models. We infer that it is a peculiar intrinsic property leading to results useful for plasma diagnostics and other applications. The transition rates from $^{5}S_{2}^{\ensuremath{\circ}}$ change considerably as a result of the Breit interaction, because the line strengths of $^{3}P_{2}$--$^{5}S_{2}^{\ensuremath{\circ}}$ ($\ensuremath{\lambda}135.560$ nm) and $^{3}P_{1}$--$^{5}S_{2}^{\ensuremath{\circ}}$ ($\ensuremath{\lambda}135.851$ nm) are different in sensitivity to this effect. This affects the calculations of the branching ratio and lifetime. There exist large discrepancies among several calculations of lifetimes, such as the MCHF calculation by [C. Froese Fischer and G. Tachiev, At. Data Nucl. Data Tables 87, 1 (2004)]. The main reasons are ascribed to the neglected electron correlation and relativistic effects. In addition, by checking different calculations with various sets of multireference configurations, we find that the calculations of the electric dipole matrix elements for $^{5}S_{2}^{\ensuremath{\circ}}$ in the length gauge are much more sensitive to electron correlation effects than in the velocity gauge. This may also lead to some errors in the calculations of the lifetime of $^{5}S_{2}^{\ensuremath{\circ}}$ in the length gauge.