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Numerical simulation of compound media coupling mechanism of deep mining overburden strata

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中国有色金属学会会刊：英文版 2011年第S3期21卷 631-636页

作者： YANG Fan, CHEN Shuang School of Geometrics, liaoning Technical University, fuxin 123000, China School of Geometrics Liaoning Technical University Fuxin 123000 China

Aiming at the regularity of deep mining strata movement, through the application of plate theory and discrete medium theory in establishing the coupling model of the deep mining strata composite medium, the continuum media and the non-continuum media were coupled into the compound media giant system, and the stress of compound layer and strain coupling relationship were established. The accuracy of forecasting surface subsidence in deep mining conditions was improved. The deep mining was simulated through 3-D numerical value by the FLAC3D finite difference software, and the coupling relationship and coupling layer in the strata composite layer were analyzed. The results show that, under the deep mining condition, the coupling zone is in the position of coal seam roof with the thickness of 15-20 times, on which, the stress-strain has much difference on the coupling zone. Considering interlayer effect of coupling zone can improve the prediction precision of surface subsidence.

关键词： deep mining numerical simulation coupling mechanism

Endemic error correction model and quantitative analysis of precise point positioning

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中国有色金属学会会刊：英文版 2011年第S3期21卷 642-647页

作者： JI Chang-dong, FENG Lei, XU Ai-gong School of Geomatics, liaoning Technical University, fuxin 123000, China School of Geomatics Liaoning Technical University Fuxin 123000 China

To identify the endemic error of the precise point positioning which cannot be weakened or eliminated in precise point positioning (PPP) zero-difference model, the 24 h observation data acquired from CHAN station on Oct 31st, 2010, were adopted for analyses, different correction models of various errors were discussed and their influences on traditional zero-difference model were analyzed. The results show that the errors cannot be ignored. They must be corrected with suitable models and estimated with auxiliary parameters. The influence magnitudes of all errors are defined, and the results have guiding significance to improve the accuracy of precise point positioning zero-difference model.

关键词： precise point positioning (PPP) zero-difference model endemic error GPS qualitative analysis

Quantitative calculation for the dissipated energy of fault rock burst based on gradient-dependent plasticity

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Journal of University of Science and Technology Beijing 2004年第3期11卷 197-201页

作者： Xuebin Wang Shuhong Dai Long Hai Department of Mechanics and Engineering Sciences, liaoning Technical University, fuxin 123000, China Dept. of Mech. and Eng. Sci. Liaoning Tech. Univ. Fuxin 123000 China

The capacity of energy absorption by fault bands after rock burst wascalculated quantitatively according to shear stress-shear deformation curves considering theinteractions and interplaying among microstructures due to the heterogeneity of strain softeningrock materials. The post-peak stiffness of rock specimens subjected to direct shear was derivedstrictly based on gradient-dependent plasticity, which can not be obtained from the classicalelastoplastic theory. Analytical solutions for the dissipated energy of rock burst were proposedwhether the slope of the post-peak shear stress-shear deformation curve is positive or not. Theanalytical solutions show that shear stress level, confining pressure, shear strength, brittleness,strain rate and heterogeneity of rock materials have important influence on the dissipated *** larger value of the dissipated energy means that the capacity of energy dissipation in the formof shear bands is superior and a lower magnitude of rock burst is expected under the condition ofthe same work done by external shear force. The possibility of rock burst is reduced for a lowersoftening modulus or a larger thickness of shear bands.

关键词： rock burst heterogeneity dissipated energy plastic strain gradient post-peak stiffness characteristic length fault band strain softefiing

A NUMERICAL MODEL OF LAMELLAR SPACING OF Al-Si EUTECTIC

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Acta Metallurgica Sinica(English Letters) 2001年第4期14卷 291-295页

作者： W.Q. Zhang and L. Xiao School of Mechanical Engineering, liaoning Technical University, fuxin 123000, China Sch. of Mech. Eng. Liaoning Technol. Univ. Fuxin 123000 China

A numerical model is established to simulate the concentration field in irregular lamel- lar eutectic of Al-Si system. Both the undercooling and spacing are dependent on the g... 详细信息

A numerical model is established to simulate the concentration field in irregular lamel- lar eutectic of Al-Si system. Both the undercooling and spacing are dependent on the growth rate and the temperature gradient, and increasing growth rate causes an in- crease of undercooling but a decrease of lamellar spacing, while increasing temperature gradient Leads to a decrease of Lamellar spacing. The computed results are in good agreement with experimental observations.

关键词： irregular eutectic Lamellar spacing undercooling growth rate

Volume Change of Heterogeneous Quasi-brittle Materials in Uniaxial Compression

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Journal of Wuhan University of Technology(Materials Science) 2006年第3期21卷 162-167页

作者：王学滨 Department of Mechanics and Engineering Sciences Liaoning Technical University Fuxin 123000China

The volumetric strain was categorized into elastic and plastic parts. The farmer camposed of axial and lateral strains is uniform and determined by Hooke＇s law ; however, the latter consisting of axial and lateral strains is a fuaction af thickness af shear band determined by grndieat-dependeat plasticity by cansidering the heterngeneity of quasi- brittle materials. The non- uniform lateral strain due to the fact that shear band was farmed in the middle of specimen was averaged within specimen to precisely assess the volumetric strain. Then, the analytical expression for volumetric strain was verified by comparison with two earlier experimental results for concrete and rack. Finally, a detailed parametric study was carried out to investigate effects of constitutive parameters （ shear band thickness, elastic and softening rnoduli ） and geometrical size of specimen（ height and width of specimen ） on the volume dilatancy.

关键词： quasi-brittle material heterogeneity volume dilatancy axial compression strain localization non-uniformity of lateral strain shear band thickness

Comparison of methods to transition geodetic latitude

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中国有色金属学会会刊：英文版 2005年第S1期15卷 234-235页

作者： SHI Jin-feng, LI Gang (liaoning Technical University, fuxin 123000, China) liaoning Tech Univ Fuxing 123000 Peoples R China

With the wide application of GPS technology, the application of the system of space rectangular coordinates is more and more extensive. Transformation of space rectangular coordinates into geodetic coordinates becomes a very popular problem. In order to evaluate various kinds of algorithms existing for solving the problem, three evaluation criteria of the algorithm were put forward at first, that is, precision, calculation speed and algorithm regional suitability. After given some basic formula, three kinds of representative algorithms, classics iteration algorithm, ellipsoidal parameter transformation algorithm and rational polynomials approximation algorithm were introduced. Through a test program made by MATLAB, these three kinds of algorithms were compared. Some helpful conclusions were drawn.

关键词： geodetic latitude numerical method coordinate transition geodetic coordinates rectangular coordinates

Simulation on range of surface subsidence in worked-out section by discrete element method

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中国有色金属学会会刊：英文版 2005年第S1期15卷 128-131页

作者： YANG Fan, MA Feng-hai (liaoning Technical University, fuxin 123000, China) liaoning Tech Univ Fuxing 123000 Peoples R China

To the issue of surface subsidence because of mining, the range of surface subsidence is simulated and the law of falling and deformation is obtained by the discrete element method. The numerical simulating method can predict angle of displacement and deformation in light of displacement value, meanwhile the results of simulation also provide scientific reference for estimating falling angle and determining the range of surface subsidence.

关键词： discrete element method surface subsidence numerical simulat on angle of subsidence

Renewing urban large-scale topographical maps by using of Quick Bird panchromatic remote sensing images

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中国有色金属学会会刊：英文版 2005年第S1期15卷 164-167页

作者： SONG Wei-dong, KANG Jia-yin (liaoning Technical University, fuxin 123000, China) liaoning Tech Univ Fuxing 123000 Peoples R China

Urban large-scale topographical maps can be renewed by means of overlapping the original digital line graph (DLG) and up-to-date remote sensitive images which have high precision and have been orthographically rectified precisely. Quick Bird panchromatic remote sensing image is used and an urban area with even terrain and dense buildings is selected as experimental area. Ground control points (GCPs) are selected on a new 1∶500 topographical map and multinomial model is applied for rectification. After rectification the absolute positional error of a single point of the image is less than 1m, therefore this method is suitable for renewing topographical maps of up to (1∶2 000) scale.

关键词： Quick Bird geometry rectification renewing of topographic maps

Fitting on elements of exterior orientation utilizing SPOT-5 raw data file

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中国有色金属学会会刊：英文版 2005年第S1期15卷 35-37页

作者： SONG Wei-dong~1, WANG Wei-xi~1, HU Xing-hua~2 (1. liaoning Technical University, fuxin 123000, China 2. liaoning Technical University, fuxin 123000, China) liaoning Tech Univ Fuxing 123000 Peoples R China liaoning Tech Univ Fuxing 123000 Peoples R China

In traditional pattern, the calculation of elements of exterior orientation is to calculate the elements of image forming moment by using fundamental ground control points. Utilizing satellite raw data file directly, which holds abundant information and using the numerical analysis methods of modern mathematics, the parameter equations about each element of exterior orientation are adjused and the elements of image forming moment under some precision are calculated.

关键词： elements of exterior orientation ground control point numerical analysis parameter equation