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Underground ground control monitoring and interpretation,and numerical modeling, and shield capacity design

International Journal of Mining Science and Technology 2019年第1期29卷 79-85页

作者： Syd S.Peng Jingyi cheng feng du Yuting Xue Department of Mining Engineering West Virginia University Key Laboratory of Deep Coal Resource Mining(CUMT) Ministry of Education of ChinaSchool of MinesChina University of Mining&TechnologyXuzhou School of Energy Science and Engineering Henan Polytechnic University

Mine or longwall panel layout is a 3D structure with highly non-uniform stress distribution. Recognition of such fact will facilitate underground problem identification/investigation and solving by numerical modeling through proper model construction. due to its versatility, numerical modeling is the most popular method for ground control design and problem solving. However numerical modeling results require highly experienced professionals to interpret its validity/applicability to actual mining operations due to complicated mining and geological conditions. Underground ground control monitoring is routinely performed to predict roof behavior such as weighting and weighting interval without matching observation of face mining condition while the mining pressures are being monitored, resulting in unrealistic interpretation of the obtained data on mining pressure. The importance of ground control pressure monitoring and simultaneous observation of mining and geological conditions is illustrated by an example of shield leg pressure monitoring and interpretation in an U.S. longwall coal mine: it was found that the roof strata act like a plate, not an individual block of the size of a shield dimension, as commonly assumed by all researchers and shield capacity is not a fixed property for a longwall panel or a mine or a coal seam. A new mechanism on the interaction between shield's hydraulic leg pressure and roof strata for shield loading is proposed.

关键词： Mine structure Ground control monitoring Numerical modeling Shield leg pressure Periodic weighting

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Automation in U.S. longwall coal mining: A state-of-the-art review

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International Journal of Mining Science and Technology 2019年第2期29卷 151-159页

作者： Syd S.Peng feng du Jingyi cheng Yang Li West Virginia University School of Energy Science and Engineering Henan Polytechnic University School of Mines China University of Mining and Technology College of Resource and Safety Engineering China University of Mining and Technology (Beijing)

This paper reviews the development of U.S. longwall mining from an unknown to became the world standard in the past five decades with emphasis on automation. Large scale longwall face equipment were imported from Germany and United Kingdom to increase production in the 1970 s and great effort was made to improve them to suit U.S. conditions, rather than domestic market. Automation began with the development of electrohydraulic shields in 1984 and continue to present. Introduction of first generation semi-automated longwall system occurred in 1995 and step-to-step improvement continues to present following the development of sensor technology and internet of things(IOT). Since then, emphasis on new development has been concentrated on the improvement of equipment reliability, miner's health and safety as well as production, including dust control techniques, proximity sensor, anti-collision and remote control. Automation is classified into two categories: automation of individual face equipment and automation of longwall system. The automation development of longwall system is divided into three stages: shearer-initiated-shield-advance(SISA), semi-automated longwall system, and remote control shearer.

关键词： Longwall mining Automation Shield Shearer AFC

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EXPERIMENTAL MEASUREMENT AND NUMERICAL SIMULATION FOR FLOW FIELD AND FILM COOLING EFFECTIVENESS IN FILM-COOLED TURBINE

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Journal of Hydrodynamics 2007年第4期19卷 459-466页

作者： YUAN feng ZHU Xiao-cheng du Zhao-hui School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China

Numerical simulation of three-dimensional flow field and film cooling effectiveness in film-cooled turbine rotor and stationary turbine cascade were carried out by using the k- ε turbulence model, and the predictions of the three-dimensional velocities were compared with the measured results by Laser-Doppler Velocimetry （LDV）. Results reveal the secondary flow near the blade surface in the wake region behind the jet hole. Compared with the stationary cascade, there are the centrifugal force and Coriolis force existing in the flow field of the turbine rotor, and these forces make the three-dimensional flow field change in the turbine rotor, especially for the radial velocity. The effect of rotation on the flow field and the film cooling effectiveness on the pressure side is more apparent than that on the suction side as is shown in the computational and measured results, and the low film cooling effectiveness appears on the pressure surface of the turbine rotor blade compared with that of the stationary cascade.

关键词： film-cooled cascade three-dimensional effectiveness Laser-Doppler simulation turbine rotor stationary turbine flow field film cooling Velocimetry (LDV) numerical

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Bacterial diversity in activated sludge from a consecutively aerated submerged membrane bioreactor treating domestic wastewater

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Journal of Environmental Sciences 2008年第10期20卷 1210-1217页

作者： du, cheng WU, Zhenbin XIAO, Enrong ZHOU, Qiaohong cheng, Shuiping LIANG, Wei HE, feng State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China Graduate University Chinese Academy of Sciences Beijing 100039 China

The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphism (RFLP). Of the screened clones, almost full-length 16S rDNA sequences of 64 clones were sequenced. Phylogenetic tree was constructed with a database containing clone sequences from this study and bacterial rDNA sequences from NCBI for identification purposes. The 90.6% of the clones were a?l...

关键词： bacterial diversity restriction fragment length polymorphism (RFLP) submerged membrane bioreactor (SMBR) 16S rDNA clone library

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Passive Control of Flow-Induced Vibration(FIV)by Helical Strakes for Two Staggered Flexible Cylinders

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China Ocean Engineering 2021年第4期35卷 475-489页

作者： XU Wan-hai WANG Qi-cheng QIN Wen-qi du Zun-feng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China CIMC Offshore Co.Ltd Shenzhen 518000China

Helical strake is a widely-used device for passive flow-induced vibration(FIV)control of cylindrical *** is omnidirectional and can effectively reduce FIV response *** on the passive FIV control for cylindrical structures are mainly concerned with a single isolated cylinder,while the influence of wake interference between multiple cylinders on FIV suppression devices is less considered up to *** engineering applications,multiple flexible cylinders with large aspect ratios can be subjected to complex flow forces,and the effects of wake interference are *** FIV suppression effect of helical strake of a common configuration(17.5D pitch and 0.25D height,where D is the cylinder diameter)in two staggered cylinders system is still *** paper systematically studied the FIV response of multiple cylinders system fitted with the helical strakes by model *** relative spatial position of the two cylinders is fixed at S=3.0D and T=8.0D,which ensures the cylindrical structures in the flow interference *** experimental results show that the helical strakes effectively reduce the FIV response on staggered upstream cylinder,and the suppression efficiency is barely affected by the smooth or straked downstream *** corresponding FIV suppression efficiency on the downstream cylinder is remarkably reduced by the influence of the upstream wake *** wake-induced vibration(WIV)phenomenon is not observed on the staggered downstream cylinder,which normally occurs on the downstream straked cylinder in a tandem arrangement.

关键词： flow-induced vibration(FIV) passive control helical strakes flexible cylinders staggered arrangement

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A general method for one-step synthesis of monofluoroiodane(Ⅲ)reagents using silver difluoride

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Chinese Chemical Letters 2022年第11期33卷 4834-4837页

作者： Jing Ren Meng-cheng Jia feng-Huan du Chi Zhang State Key Laboratory of Elemento-Organic Chemistry The Research Institute of Elemento-Organic ChemistryCollege of ChemistryNankai UniversityTianjin 300071China

Herein we report a new general method for one-step synthesis of four kinds of fluoroiodane(Ⅲ)reagents by treating the corresponding aryl iodides with silver difluoride(AgF_(2)).This is the first method applicable for the synthesis of all four fluoroiodane(Ⅲ)reagents including p-iodotoluene difluoride(1),fluoro-benziodoxole(2),fluoro-benziodoxolone(3),and fluoro-N-acetylbenziodazole(4).AgF_(2)was firstly employed in the direct oxidative fluorination of iodobenzene and thus has shown its outstanding oxidation and fluorine-transfer *** use of AgF_(2)has improved the synthesis of fluoroiodane(Ⅲ)reagents by shortening the reaction steps,avoiding the use of hazardous reagents,and simplifying the experimental *** was worth noting that we have developed the first one-step direct synthetic method for 3,while 3 can only be synthesized through Cl→F ligand exchange reaction previously.

关键词： Monofluoroiodane(Ⅲ)reagents Silver difluoride Iodobenzene derivatives One-step synthesis DFT calculations

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Recent progress on photoactive nonprecious transition-metal complexes

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Science China Chemistry 2025年第1期 46-95页

作者： Zhong-Liang Gong Hong-Jie Zhang Yan cheng Jianxun Liu Yuhan Ai Yaqin Li Zhihui feng Qiong Zhang Shaolong Gong Yong Chen Chang-Jiang Yao Yuan-Yuan Zhu Liang-Jin Xu Yu-Wu Zhong CAS Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences State Key Laboratory of Structural Cemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences School of Chemistry and Chemical Engineering Anhui Key Laboratory of Advanced Catalytic Materials and Reaction EngineeringHefei University of Technology State Key Laboratory of Explosion Science and Safety Protection School of Mechatronical Engineering Beijing Institute of Technology College of Chemistry and Molecular Sciences Hubei Key Lab on Organic and Polymeric Optoelectronic Materials Wuhan University School of Chemistry and Chemical Engineering Anhui University Key Laboratory of Photochemical Conversion and Optoelectronic Materials & CAS-HKU Joint Laboratory on New Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences

Photoactive complexes of nonprecious transition metals, mainly including those in the first-row and partially the second-row of the Periodic table of elements, have received increasing attention in view of their low cost and long-term sustainability. They are recognized as promising alternatives to noble transition metal complex congeners that have been extensively studied in optoelectronic devices, artificial photosynthesis, photocatalysis, biodiagnostics, and therapeutics, etc. This review is devoted to a comprehensive summary on the classical and recent advances on photoactive nonprecious transition metal complexes, including photoactive Zr, V, Cr, Mo, and W complexes, Mn complexes and hybrids, Fe, Co, Ni, and Cu complexes, and Zn and Cd complexes and hybrids. A particular focus is given on the molecular design, modulation of photophysical and photochemical properties, and applications of the representative and lately-developed nonprecious metal complexes. In addition, a perspective on the future development in this field is provided at the end of this review.

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Clonal Strategy Algorithm Based on the Immune Memory

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Journal of Computer Science & Technology 2005年第5期20卷 728-734页

作者： Ruo-Chen Liu Li-cheng Jiao Hai-feng du Institute of Intelligent Information Processing Xidian University Xi＇an 710071 P.R. China Department of Mathematics Northwest University Xi＇an 710069 P.R. China

Based on the clonal selection theory and immune memory mechanism in the natural immune system, a novel artificial immune system algorithm, Clonal Strategy Algorithm based on the Immune Memory （CSAIM）, is proposed in this paper. The algorithm realizes the evolution of antibody population and the evolution of memory unit at the same time, and by using clonal selection operator, the global optimal computation can be combined with the local searching. According to antibody-antibody （Ab-Ab） affinity and antibody-antigen （Ab-Ag） affinity, the algorithm can allot adaptively the scales of memory unit and antibody population. It is proved theoretically that CSAIM is convergent with probability 1. And with the computer simulations of eight benchmark functions and one instance of traveling salesman problem （TSP）, it is shown that CSAIM has strong abilities in having high convergence speed, enhancing the diversity of the population and avoiding the premature convergence to some extent.

关键词： artificial immune system clonal selection, immune memory evolutionary computation, traveling salesman problem

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Temperature of Transformation from Fullerite to Amorphous Carbon

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Chinese Physics Letters 1995年第4期12卷 207-209页

作者： cheng Guangxu GU Gang ZANG Wencheng du Youwei feng duan Center of Materials Analysis Nanjing UniversityNanjing 210008 the National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210008

Raman spectra during the transformation from fullerite to amorphous carbon are *** transformation temperature is obtained from intensity ratio of Stokes and anti-Stokes lines by using Placzek’s *** temperature,less t... 详细信息

关键词： transformation Transformation Stokes

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Role of Substrate Roughness in ZnO Nanowire Arrays Growth by Hydrothermal Approach

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Acta Metallurgica Sinica(English Letters) 2016年第3期29卷 237-242页

作者： Qiu-Hong Wang Chao-Long Tang cheng-Ming Jiang Dan-feng du feng Wang Jin-Hui Song Department of Metallurgical and Materials Engineering Center for Materials for Information Technology(MINT)University of Alabama Department of Mechanical Engineering Changzhou Institute of Mechatronic Technology

The role of substrate roughness in ZnO nanowire（NW） arrays hydrothermal growth has been systematically *** silicon substrates with different roughness by chemical etching have been selected to grow ZnO NW arrays hydrothermally after sputtering 5-nm-thick ZnO seed layer as *** as-grown samples reveal that average diameters and number densities of ZnO NW arrays are inversely proportional to the increasing substrate roughness observed by atomic-force microscopy and scanning electron ***,the theoretically derived equations based on nucleation with the Gibbs free energy to describe relations of substrate roughness versus average NW diameter and NW number density match well with experimental *** results in this paper can be used to control the number density and the average diameter of ZnO NW arrays by alternating substrate roughness.

关键词： ZnO nanowire Chemical synthesis Atomic-force microscopy Substrate roughness

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