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Assessment and control of the mine tremor disaster induced by the energy accumulation and dispersion of thick-hard roofs

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International Journal of Mining Science and Technology 2024年第7期34卷 925-941页

作者： Bin Yu Mingxian peng yang Tai Shuai Guo State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Chongqing UniversityChongqing 400044China School of Mines China University of Mining and TechnologyXuzhou 221116China

In order to solve the problem that current theory models cannot accurately describe thick-hard roof(THR)elastic energy and assess the mine tremor disasters,a theoretical method,a Timoshenko beam theory on Winkler foundation was adopted to establish the THR’s periodic breaking *** superposition principle was used for this complex model to derive the calculation formulas of the elastic energy and impact load on hydraulic ***,the influence of roof thickness h,cantilever length L_(1),and load q on THR’s elastic energy and impact load was ***,the effect of mine tremor disasters was ***,it is revealed that:(1)The THR’s elastic energy U exhibits power-law variations,with the fitted relationships U=0.0096L_(1)^(3.5866^),U=5943.9h^(-1.935),and U=21.049q^(2).(2)The impact load on hydraulic supports F_(ZJ) increases linearly with an increase in the cantilever length,thickness,and applied *** fitted relationships are F_(ZJ)=1067.3L_(1)+6361.1,F_(ZJ)=125.89h+15100,and F_(ZJ)=10420q+3912.6.(3)Ground hydraulic fracturing and liquid explosive deep-hole blasting techniques effectively reduce the THR’s cantilever length at periodic breakages,thus eliminating mine tremor disasters.

关键词： Dynamic disaster Energy Hard and thick roof Timoshenko beam

Terminal attitude selection method of missile attack aircraft

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Chinese Journal of Aeronautics 2024年第2期37卷 385-400页

作者： peng HOU yang PEI Yuxue GE Mengjie ZHU School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Research Department Shanghai Electro-Mechanical Engineering InstituteShanghai 201108China

The appropriate terminal attitude of missile is important to improve the damage effectiveness of fragmentation warhead against aircraft *** this paper,three missile terminal attitude selection methods are proposed to solve the problem of terminal attitude selection in different situations according to their respective evaluation *** MVE-based method uses the damage probability of each detonation point around the aircraft at a given attitude of missile to calculate the Mean Volume of Effectiveness(MVE)at the corresponding attitude,and then uses the MVE for different attitudes to select the terminal strike *** detonation position-based method addresses the case where the missile detonation position can be assessed in *** the effects of missile guidance errors and fuze activation position errors,Monte Carlo simulations are used to calculate the damage probability of aircraft with different strike attitudes,from which the terminal strike attitude is *** BP-ANN model-based method uses the constructed Back Propagation Artificial Neural Network(BP-ANN)model instead of simulation to calculate the evaluation indexes in the corresponding cases of MVE-based method and Detonation position-based method,which can improve the efficiency of attitude *** are conducted for different scenarios to verify the feasibility and effectiveness of the proposed method.

关键词： Aircraft vulnerability Attitude selection BP-ANN Damage probability Damage effectiveness

Recovery of scandium from silicate minerals by high-pressure leaching in sulfuric acid

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Journal of Rare Earths 2024年第7期42卷 1375-1384,I0007页

作者： peng Yan Xiaoming Chen Likun Gao Bo yang Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming650093China Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming650093China School of Chemistry and Chemical Engineering Kunming UniversityKunming650214China

This study investigated the leaching of scandium from a Sc-bearing silicate *** Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%*** main Sc-bearing minerals are limonite,chlorite,sericite,and hornblende,in the form of ***-pressure leaching(HPL)with sulfuric acid(98 wt%)and NaF was used to dispose this *** Sc leaching efficiency of 91.82%was obtained under the optimum conditions,which are pressure of 5.0×10^(5) Pa,A/O value of 1.1,L/S value of 1.8,NaF dosage of 2 wt%,at 130℃ for 6 *** X-ray diffraction(XRD)and scanning electron microscopy(SEM)results show that the residue is mainly quartz phase in the multihole *** with ordinary leaching for silicate,high-pressure leaching has significant advantages in saving acid and energy consumption.

关键词： Silicate minerals Scandium High-pressure Leaching Concentrated sulfuric acid Rare earths

A self-organization formation configuration based assignment probability and collision detection

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Journal of Systems Engineering and Electronics 2024年第1期35卷 222-232页

作者： SONG Wei WANG Tong yang Guangxin ZHANG peng School of Harbin Engineering University Harbin 150001China Chinese Aeronautical Establishment Beijing 100010China

The formation control of multiple unmanned aerial vehicles(multi-UAVs)has always been a research *** on the straight line trajectory,a multi-UAVs target point assignment algorithm based on the assignment probability is proposed to achieve the shortest overall formation path of multi-UAVs with low complexity and reduce the energy *** order to avoid the collision between UAVs in the formation process,the concept of safety ball is introduced,and the collision detection based on continuous motion of two time slots and the lane occupation detection after motion is proposed to avoid collision between *** on the idea of game theory,a method of UAV motion form setting based on the maximization of interests is proposed,including the maximization of self-interest and the maximization of formation interest is proposed,so that multi-UAVs can complete the formation task quickly and reasonably with the linear trajectory assigned in ***,through simulation verification,the multi-UAVs target assignment algorithm based on the assignment probability proposed in this paper can effectively reduce the total path length,and the UAV motion selection method based on the maximization interests can effectively complete the task formation.

关键词： straight line trajectory assignment probability collision detection lane occupation detection maximization of interests

Growth of Ag/g-C_(3)N_(4) nanocomposites on nickel foam to enhance photocatalytic degradation of formaldehyde under visible light

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Journal of Environmental Sciences 2024年第3期137卷 432-442页

作者： Ze Wang Zhi Huang Jiang Yu Xiao shao Weidong peng Jie Yu Yinying Jiang Department of Environmental Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Institute of New Energy and Low Carbon Technology Sichuan UniversityChengdu 610065China School of Agriculture and Environment University of Western AustraliaPerth 6907Western AustraliaAustralia Yibin Institute of Industrial Technology Sichuan UniversityYibin 644000China

Formaldehyde is a pollutant that significantly affects the indoor air ***,conventional remediation approaches can be challenging to deal with low-concentration formaldehyde in an indoor *** this study,Photocatalysts of Ag/graphitic carbon nitride(g-C_(3)N_(4))/Ni with 3D reticulated coral structure were prepared by thermal polymerization and liquid phase photo-deposition,using nickel foam(NF)as the *** demonstrated that when the Ag concentration was 3%,and the relative humidity was 60%,the Ni/Ag/g-C_(3)N_(4)showed the maximum degradation rate of formaldehyde at 90.19%under visible light irradiation,and the formaldehyde concentration after degradation was lower than the Hygienic standard stated by the Chinese *** porous structure of Ni/Ag/g-C_(3)N_(4)and the formation of Schottky junctions promoted the Adsorption efficiency and degradation of formaldehyde,while the nickel foam carrier effectively promoted the desorption of degradation ***,the degradation rate was only reduced by3.4%after 16 recycles,the three-dimensional porous structure extended the lifetime of the *** study provides a new strategy for the degradation of indoor formaldehyde at low concentrations.

关键词： Graphitic carbon nitride(g-C_(3)N_(4)) Nickel foam(NF) Ag Formaldehyde Photocatalysis

3-D Tunnel Seismic Advance Prediction Method with Wide Illumination and High-Precision

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Journal of Earth Science 2024年第3期35卷 970-979页

作者： peng Guan Cuifa shao Yuyong Jiao Guohua Zhang Junpeng Zou Fei Tan Faculty of Engineering China University of GeosciencesWuhan 430074China

Tunnel seismic advance prediction can effectively reduce the construction risk during tunnel *** with the 2-D method,the 3-D method is more conducive to describing the spatial characteristics of the geological body by adding the seismic data in the vertical ***,some drawbacks still need improvement in the current 3-D tunnel seismic prediction method.(1)The geometry is complex,which is destructiveness,high cost,and time-consuming,and will delay the tunnel construction schedule.(2)Illumination of the anomalous body is insufficient,and the precision of migration imaging is low.(3)Shot points are far away from the tunnel face,the energy loss at the shot points is more serious.(4)The received signals at the tunnel wall have the surface wave with strong energy when the shot points are placed on the tunnel wall.(5)The geometry is not linear,so the directional filtering method cannot be used to extract the reflection *** overcome the drawbacks of the current prediction method,a new 3-D symmetrical tunnel seismic prediction method is *** geophones are installed on the tunnel wall,two on the left side,two on the right side,and two on the top ***-four shot points are placed on the tunnel face and near both sides of the tunnel wall,twelve shot points on the left side and twelve shot points on the right *** shot points will move along with the forward excavation of the *** wavefield analysis,illumination statistics,and 3-D reverse time migration imaging are used to evaluate the proposed *** result of modeled data indicates that the proposed 3-D geometry has some advantages:(1)the geometry is simple and the geophone installation time is short;(2)it has high illumination energy,wide illumination range,and can improve the prediction distance and imaging accuracy;(3)the proposed 3-D method can better estimate the velocity of surrounding rock and is more conducive to extracting the reflection wave with high resolut

关键词： tunnels excavation geophone shot points migration imaging method engineering ge-ology.

Experimental Study of Local Scour Around Four Piles Under Different Attack Angles and Gap Ratios

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China Ocean Engineering 2024年第4期38卷 612-624页

作者： LIU Ming-ming TANG Guo-qiang JIN Xin GENG shao-yang School of Architecture and Engineering Liaocheng UniversityLiaocheng 252000China Water-Sediment Regulation and Sand Effective Utilization Special Laboratory of Shandong Provincial Education Department Liaocheng UniversityLiaocheng 252000China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China College of Energy Chengdu University of TechnologyChengdu 610059China

In an effort to investigate and quantify the patterns of local scour,researchers embarked on an in-depth study using a systematic experimental *** research focused on the effects of local scour around a set of four piles,each subjected to different hydromechanical *** particular,this study aimed to determine how different attack angles—the angles at which the water flow impinges on the piles,and gap ratios—the ratios of the spacing between the piles to their diameters,influence the extent and nature of scour.A comprehensive series of 35 carefully designed experiments were orchestrated,each designed to dissect the nuances in how the gap ratio and attack angle might contribute to changes in the local scour observed at the base of pile *** these experimental trials,a wealth of local scour data were collected to support the *** data included precise topographic profiles of the sediment bed around the pile groups,as well as detailed scour time histories showing the evolution of scour at strategic feature points throughout the test *** analysis of the experimental data provided interesting *** study revealed that the interplay between the gap ratio and the attack angle had a pronounced influence on the scouring dynamics of the pile *** of the key observations was that the initial phases of scour,particularly within the first hour of water flow exposure,were characterized by a sharp increase in the scour depth occurring immediately in front of the *** this initial rapid development,the scour depth transitioned to a more gradual change *** contrast,the scour topography around the piles continuously *** suggests that sediment displacement and the associated sculpting of the seabed around pile foundations are sustained and progressive processes,altering the underwater landscape over *** results of this empirical investigation have significant implications for the design and constructio

关键词： local scour piles gap ratio attack angle

Modeling and Analysis of OFDMA-NOMA-RA Protocol Considering Imperfect SIC in Multi-User Uplink WLANs

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Computers, Materials & Continua 2024年第6期79卷 5273-5294页

作者： Hailing yang Suoping Li Duo peng School of Science Lanzhou University of TechnologyLanzhou730050China School of Computer&Communication Lanzhou University of TechnologyLanzhou730050China

To address the problems of network congestion and spectrum resources shortage in multi-user large-scale scenarios,this paper proposes a twice random access OFDMA-NOMA-RA protocol combining the advantages of orthogonal frequency division multiple access(OFDMA)and non-orthogonal multiple access(NOMA).The idea of this protocol is that OFMDA is used to divide the entire frequency field into multiple orthogonal resource units(RUs),and NOMA is used on each RU to enable more users to access the channel and improve spectrum *** on the protocol designed in this paper,in the case of imperfect successive interference cancellation(SIC),the probability of successful competition subchannels and the outage probability are derived for two scenarios:Users occupy the subchannel individually and users share the ***,when two users share the channel,the decoding order of the users and the corresponding probabilities are ***,the system throughput is *** achieve better outage performance in the system,the optimal power allocation algorithm is proposed in this paper,which enables the optimal power allocation strategy to be *** results show that the larger the imperfect SIC coefficient,the worse the outage performance of weak *** with pure OFDMA and NOMA,OFDMA-NOMA-RA always maintains an advantage when the imperfect SIC coefficient is less than a specific value.

关键词： Orthogonal frequency division multiple access(OFDMA) non-orthogonal multiple access(NOMA) random access(RA) imperfect successive interference cancellation(Imperfect SIC) outage probability

Autofocus by Lissajous scanning in time reversal optical scanning holography

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CHINESE OPTICS LETTERS 2024年第8期22卷 080501-080501页

作者： Liu, Jie Ou, Haiyan Wang, Hua peng, Lin shao, Wei Univ Elect Sci & Technol China Shenzhen Inst Adv Study Shenzhen 518000 Peoples R China Univ Elect Sci & Technol China Sch Phys Chengdu 611731 Peoples R China Guilin Univ Elect Technol Key Lab Cognit Radio & Informat Proc Guilin 541004 Peoples R China

In this Letter, an autofocusing method in optical scanning holography (OSH) system is proposed. By introducing Lissajous scanning into multiple signal classification (MUSIC) method in time-reversal (TR) OSH, the axial locations of the targets can be retrieved with better resolution and the peak prominence increases from 0.21 to 0.34. The feasibility of this method is confirmed by simulation as well as experiment.

关键词： digital holography Lissajous scanning image reconstruction axial localization SECTIONAL IMAGE-RECONSTRUCTION SCATTERING MICROSCOPY TARGETS