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Comprehensive evaluation of high-steep slope stability and optimal high-steep slope design by 3D physical modeling

International Journal of Minerals,Metallurgy and Materials 2015年第1期22卷 1-11页

作者： Xing-ping Lai Peng-fei Shan Mei-feng cai Fen-hua Ren Wen-hui Tan School of Energy Engineering Xi'an University of Science and Technology School of Civil and Environmental Engineering University of Science and Technology Beijing Key Laboratory of the Ministry of Education of China for Efficient Mining and Safety of Metal Mines University of Science and Technology Beijing

High-steep slope stability and its optimal excavation design in Shuichang open pit iron mine were analyzed based on a large 3D physical simulation technique. An optimal excavation scheme with a relatively steeper slope angle was successfully implemented at the northwest wall between Nos. 4 and 5 exploration lines of Shuichang Iron Mine, taking into account the 3D scale effect. The phys-ico-mechanical properties of rock materials were obtained by laboratory tests conducted on sample cores from exploration drilling directly from the iron mine. A porous rock-like composite material was formed for the model, and the mechanical parameters of the material were assessed experimentally;specifically, the effect of water on the sample was quantitatively determined. We adopted an experimental setup using stiff modular applied static loading to carry out a visual excavation of the slope at a random depth. The setup was equipped with acous-tic emission （AE） sensors, and the experiments were monitored by crack optical acquirement, ground penetrating radar, and close-field pho-togrammetry to investigate the mechanisms of rock-mass destabilization in the high-steep slope. For the complex study area, the model re-sults indicated a clear correlation between the model＇s destabilization resulting from slope excavation and the collected monitoring informa-tion. During the model simulation, the overall angle of the slope increased by 1-6 degrees in different sections. Dramatically, the modeled excavation scheme saved over 80 million tons of rock from extraction, generating enormous economic and ecological benefits.

关键词： slope stability analysis excavation design three-dimensional models physical simulation

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Structure instability forecasting and analysis of giant rock pillars in steeply dipping thick coal seams

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International Journal of Minerals,Metallurgy and Materials 2015年第12期22卷 1233-1244页

作者： Xing-ping Lai Huan Sun Peng-fei Shan Ming cai Jian-tao Cao feng Cui Energy School Xi’an University of Science and Technology Key Laboratory of Western Mines and Hazard Prevention (Ministry of Education of China) Bharti School of Engineering Laurentian University

Structure stability analysis of rock masses is essential for forecasting catastrophic structure failure in coal seam mining. Steeply dipping thick coal seams （SDTCS） are common in the Urumqi coalfield, and some dynamical hazards such as roof collapse and mining-induced seismicity occur frequently in the coal mines. The cause of these events is mainly structure instability in giant rock pillars sand- wiched between SDTCS. Developing methods to predict these events is important for safe mining in such a complex environment. This study focuses on understanding the structural mechanics model of a giant rock pillar and presents a viewpoint of the stability of a trend sphenoid fractured beam （TSFB）. Some stability index parameters such as failure surface dips were measured, and most dips were observed to be between 46° and 51°. We used a digital panoramic borehole monitoring system to measure the TSFB＇s height （△H）, which varied from 56.37 to 60.50 m. Next, FLAC^3D was used to model the distribution and evolution of vertical displacement in the giant rock pillars; the results confirmed the existence of a TSFB structure. Finally, we investigated the acoustic emission （AE） energy accumulation rate and observed that the rate commonly ranged from 20 to 40 kJ/min. The AE energy accumulation rate could be used to anticipate impeding seismic events related to structure failure. The results presented provide a useful approach for forecasting catastrophic events related to structure instability and for developing hazard prevention technology for mining in SDTCS.

关键词： coal mining structural instability rock pillars forecasting acoustic emission (AE) steeply dipping coal beds

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MULTIGRID METHODS FOR THE GENERALIZED STOKES EQUATIONS BASED ON MIXED FINITE ELEMENT METHODS

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Journal of Computational Mathematics 2002年第2期20卷 129-152页

作者： Qing-ping Deng Xiao-ping feng Department of Mathematics The University of Tennessee 美国 Knoxville TN 37996

Examines multigrid methods for the generalized stationary Stokes equations which are discretized by various mixed finite element methods. Information on a multigrid algorithm; preliminaries of convergence; Application... 详细信息

关键词： Generalized Stokes equations Mixed methods Multigrid methods.

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Single channel signal component separation using Bayesian estimation

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Journal of Systems Engineering and Electronics 2007年第1期18卷 33-39页

作者： cai Quanwei Wei ping Xiao Xianci Coll. of Electronic Engineering Univ. of Electronic Science and Technology Chengdu 610054 P.R. China

A Bayesian estimation method to separate multicomponent signals with single channel observation is presented in this paper. By using the basis function projection, the component separation becomes a problem of limited parameter estimation. Then, a Bayesian model for estimating parameters is set up. The reversible jump MCMC （Monte Carlo Markov Chain） algorithmis adopted to perform the Bayesian computation. The method can jointly estimate the parameters of each component and the component number. Simulation results demonstrate that the method has low SNR threshold and better performance.

关键词： Signal component separation Single channel Bayesian estimation Reversible jump MCMC

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Ligand Effects in Dinitrogen Hydrogenation of Binuclear Zirconium Complexes

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Chinese Journal of Structural Chemistry 2008年第2期27卷 238-244页

作者： LIU cai-ping WU Ke-Chen State Key Laboratory of Structural Chemistry Fujian Institute of Research on theStructure of Matter The Chinese Academy of Sciences Fuzhou Fujian 350002 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

In this work, we report a theoretical exploration of the ground-state electronic structures and molecular vibrational properties of a series of binuclear zirconium complexes in the framework of density functional theory （DFT） employing the B3LYP hybrid functional. The calculated results reveal that the electronic structure of the complex [（η^5-C5Me5）2Zr]2（μ^2, η^2, η^2-N2） is unfavorable for hydrogenation due to the exclusion of side-on dinitrogen in the LUMO＋ 1 molecular orbital as compared with the reactant 1 [（η^5-C5Me4H）2Zr]2（μ2,η^2,η^2-N2）. Besides, the structural feature of the hypothetical intermediate 1′, [（η^5C5Me4H）2Zr]2（μ2,η^2, η^2-N2）-n2, clearly implies the possibility of further hydrogenation. In addition, the distinguishing of vibrational modes of experimental intermediate 2, [（η^5-C5Me4H）2ZrH]2（μ2,η^2,η^2-N2H2）, indicates that the asymmetric stretching of Zr-N and Zr-H leads to dissociation. Moreover, the vibrational intensity of Zr-H is stronger than that of Zr-N. Therefore, it can be predicted that excess hydrogen atmosphere is necessary to ensure the dissociation of Zr-N bonds.

关键词： density functional theory binuclear zirconium complexes electronic structure vibrational properties dinitrogen hydrogenation

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Plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women

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Journal of Geriatric Cardiology 2015年第3期12卷 251-256页

作者： Li SHENG cai WU Yong-Yi BAI Wen-Kai XIAO Dan feng ping YE Department of Geriatric Cardiology Chinese PLA General Hospital Beijing China Department of Medical Statistics Chinese PLA General Hospital Beijing China

Objectives To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a commu- nity-based cohort. The gender differences in these associations were examined. Methods We evaluated the relationship between plasma homocysteine levels to three measures of vascular ftmction [carotid-femoral pulse wave velocity （CF-PWV）, carotid-ankle PWV （CA-PWV） and heart rate corrected augmentation index （AI）] in 1680 participants （mean age： 61.5 years; 709 men, 971 women） from communities of Beijing, China. Results In univariate analysis, plasma homocysteine levels was positively related to the CF-PWV （r = 0.211, P 〈 0.0001） and CA-PWV （r = 0.148, P 〈 0.0001）, whereas inversely associated with AI （r = -0.052, P = 0.016）. In multiple linear regression models adjusting for covariants, plasma homocysteine remained positively related to the CF-PWV （standardized 13 = 0.065, P = 0.007） in total cases. When the groups of men and women were examined separately, plasma homocysteine remained positively associated with the CF-PWV （standardized β = 0.082, P = 0.023） in men, whereas the relations between homocysteine and any of the arterial stiffness indices were not further present in women. Conclusions In Chinese population, plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women.

关键词： Arterial stiffness Gender differences Homocysteine Pulse wave velocity

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Experimental study of hydrogen-rich/oxygen-rich gas–gas injectors

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Chinese Journal of Aeronautics 2013年第5期26卷 1164-1172页

作者： Jin ping Li Mao cai Guobiao School of Astronautics Beihang University

Five types of coaxial injectors were investigated experimentally using hot hydrogen-rich gas and oxygen-rich gas, which were respectively provided by a GH2/GO2 hydrogen-rich perburner and a GH2/GO2 oxygen-rich preburner. The injectors were the shear coaxial injector, the oxidizer post expansion coaxial injector, the fuel impinging coaxial injector, the central body coaxial injector, and the shear tri-coaxial injector. The characteristic velocity efficiency and the combustor＇s wall temperatures were obtained for different design parameters through the experiments. It can be con- cluded that angles of the oxidizer post expansion and the fuel impinging have little influence on the combustion performance and the wall temperatures. The contact area between fuel and oxidizer and the mass flow rate have significant impacts on the combustion performance. The shear tri-coaxial injector has the best combustion performance but also the highest wall temperatures among the five types of injectors.

关键词： Combustion performance Experiment Gas-gas injector High mass flow rate Wall temperature

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Enhanced separation of Pd(Ⅱ)and Pt(Ⅳ)from hydrochloric acid aqueous solution using 2-((2-methoxyethyl)thio)-1H-benzimidazole

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Rare Metals 2020年第12期39卷 1473-1482页

作者： Shao-ping feng Kun Huang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Department of Chemistry College of ScienceHonghe UniversityMengzi 661199China

Separation of palladium(Pd)and platinum(Pt)by solvent extraction is difficult because of their extremely similar physicochemical *** of new extractants with a high extraction efficiency and excellent separation selectivity is the primary focus for enhancing the separation of Pd and Pt by solvent *** this study,a new extractant,2-((2-methoxyethyl)thio)-1 H-benzimidazole(MOBI),which contains N,S,and O atoms,was synthesized and used to separate Pd(Ⅱ)and Pt(Ⅳ)from a hydrochloric acid aqueous *** experimental results revealed that Pd(Ⅱ)and Pt(Ⅳ)were effectively separated under the optimal conditions:MOB I concentration of 0.005 mol·L^(-1),HCl concentration of0.2 mol·L^(-1),organic/aqueous(O/A)phase ratio of 1.0,and contact time of 15 *** separation coefficient between Pd(Ⅱ)and Pt(Ⅳ)was 1246.40,which indicates that MOBI has a higher selectivity for Pd(Ⅱ)than Pt(Ⅳ).In addition,the mechanism of coordination between Pd(Ⅱ)and MOBI was demonstrated through the slope method,Fourier transform infrared spectroscopy(FTIR),hydrogen-1 nuclear magnetic resonance spectroscopy(^(1)H NMR),and carbon-13 nuclear magnetic resonance spectroscopy(^(13)C NMR).The results revealed that MOBI could coordinate with Pd(Ⅱ)via the N atom in the benzimidazole ring of MOBI molecules to form[Pd(MOBI)_(2)Cl_(2)](O).

关键词： 2-((2-methoxyethyl)thio)-1H-benzimidazole Palladium Platinum Extraction Separation

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Effect of nitrogen addition on microstructure and erosion-corrosion behavior of stainless steel in acidic slurry

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China Foundry 2009年第3期6卷 197-201页

作者： Li ping cai Qi zhou Wei Bo kang Li feng jun School of Material Science and Engineering Henan Polytechnic UniversityJiaozuo 454000HenanChina China Yituo Group Co. Ltd.Luoyang 471004HenanChina School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China China Yituo Group Co.Ltd.Luoyang 471004HenanChina

Effect of nitrogen content on the microstructure and erosion-corrosion (E-C) behavior of stainless steel (containing about 25% Cr, 5%-6% Ni, and 1%-2% Mo) was investigated by using optical microscope(OM), potentiodynamic polarization curve and immersion method, a self-made rotating disk apparatus and scanning electron microscopy (SEM) and so on. The results show that with the increase of nitrogen content from 0 (no adding) to 0.485 wt.%, the Cr(eq)/Ni(eq) ratio of the tested materials decreases from 4.14 to 1.23 and the ferrite volume percentage of the steel tested linearly decreases approximately from 90% to 10%. The effect of nitrogen content on polarization behavior of the studied steel was not significant. All the passive current densities (I(p)) and pure corrosion rates (V(c)) of the different N content specimens in the acidic solution (slurry containing 0.1 M H(2)SO(4)+0.06% Cl(-)+0.4% F(-), the simplified zinc hydrometallurgy slurry) are too low and nearly negligible. Whereas the pure erosion rates (V(e)) of the four scenarios of the steels tested (N content, wt.%: N1, no adding; N2, 0.143%; N3, 0.289%; N4, 0485%, respectively) are much higher than their V(c) values. The V(e) values of the tested steels are in the order of N4 > N1 > N3 > N2, at the same time, the total weight loss rates (V(t)) follow the order of N4 > N1 > N3 > N2, too. N2 steel consisting of approximately equal volume fractions of ferrite (alpha) and austenite (gamma) exhibits the most excellent E-C resistance and erosion resistance, while the stainless steels possessing the big difference between alpha phase and gamma phase, such as N1 steel nearly possessing single ferrite or N4 steel nearly possessing single austenite, show poorer E-C resistance and erosion resistance.

关键词： nitrogen microstructure erosion-corrosion (E-C) duplex stainless steels

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Facile tuning of hydrogel properties by manipulating cationic-aromatic monomer sequences

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Science China Chemistry 2021年第9期64卷 1560-1568页

作者： Hailong Fan Yirong cai Jian ping Gong Institute for Chemical Reaction Design and Discovery(WPI-ICReDD) Hokkaido UniversitySapporo001-0021Japan Graduate School of Life Science Hokkaido UniversitySapporo001-0021Japan Faculty of Advanced Life Science Hokkaido UniversitySapporo001-0021Japan Global Station for Soft Matter GI-CoRE Hokkaido UniversitySapporo001-0021Japan

Copolymer hydrogels formed from cationic and aromatic monomers with identical monomer compositions but different average sequences were synthesized by free-radical copolymerization in various *** found that hydrogels with one-componentrich segments are mechanically stronger than those with adjacent-rich monomer sequences in water,while hydrogels with a rich cation-πadjacent sequence showed excellent mechanical strength and underwater adhesion in saltwater(0.7 M Na Cl).The molecular mechanisms for these behaviors are discussed in terms of polymer *** work reveals the importance of monomeric sequences in determining hydrogel properties and provides a facile approach to develop hydrogels with different properties but the same monomer composition.

关键词： free-radical polymerization monomer sequence hydrogel cation-πinteractions underwater adhesion

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