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Optimization of Center of Gravity Position and Anti-Wave Plate Angle of Amphibious Unmanned Vehicle Based on Orthogonal Experimental Method

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Computer Modeling in engineering & Sciences 2024年第5期139卷 2027-2041页

作者： Deyong Shang Xi Zhang Fengqi Liang Chunde Zhai Hang Yang Yanqi Niu school of Mechanical Electronic&Information EngineeringChina University of Mining and Technology(Beijing)Beijing100083China Institute of Intelligent mining&Robotics China University of Mining and Technology(Beijing)Beijing100083China

When the amphibious vehicle navigates in water,the angle of the anti-wave plate and the position of the center of gravity greatly influence the navigation *** the relevant research on reducing the navigation resistance of amphibious vehicles by adjusting the angle of the anti-wave plate,there is a lack of scientific selection of parameters and reasonable research of simulation results by using mathematical methods,and the influence of the center of gravity position on navigation characteristics is not considered at the same *** study the influence of the combinations of the angle of the anti-wave plate and the position of the center of gravity on the resistance reduction characteristics,a numerical calculation model of the amphibious unmanned vehicle was established by using the theory of computational fluid dynamics,and the experimental data verified the correctness of the numerical *** on this numerical model,the navigation characteristics of the amphibious unmanned vehicle were studied when the center of gravity was located at different positions,and the orthogonal experimental design method was used to optimize the parameters of the angle of the anti-wave plate and the position of the center of *** results show that through the parameter optimization analysis based on the orthogonal experimental method,the combination of the optimal angle of the anti-wave plate and the position of the center of gravity is *** the numerical simulation result of resistance is consistent with the predicted optimal *** with the maximum navigational resistance,the parameter optimization reduces the navigational resistance of the amphibious unmanned vehicle by 24%.

关键词： Amphibious unmanned vehicle orthogonal experimental design anti-wave plate center of gravity resistance characteristic

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Experimental investigation on coal pore-fracture variation and fractal characteristics synergistically affected by solvents for improving clean gas extraction

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International Journal of mining Science and Technology 2024年第3期34卷 413-425页

作者： Feilin Han Sheng Xue Chunshan Zheng Zhongwei Chen Guofu Li Bingyou Jiang Key Laboratory of Safe and Effective Coal mining of Ministry of Education Anhui University of Science and TechnologyHuainan 232001China school of Safety Science and engineering Anhui University of Science and TechnologyHuainan 232001China school of Mechanical and mining engineering University of QueenslandQLD 4072Australia State Key Laboratory of Coal and Coalbed Methane Co-mining Jincheng 048012China

Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction ***,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully *** testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal *** model between permeability,fractal dimension and porosity were *** indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to *** decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,*** treatments could lead to increasing amount of both mesopores and *** ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to ***,combined solvent could dissolve coal polar and non-polar small molecules and expand flow *** could provide reference for solvent selection and parameter optimization of permeability-enhancement technology.

关键词： Clean gas extraction Chemical solvent Experimental investigation Fractal characteristics Pore fracture

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Structure design and coordinated motion analysis of bionic crocodile robot

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Biomimetic Intelligence & Robotics 2024年第2期4卷 50-62页

作者： Jun Wang Jingya Zheng Yuhang Zhao Kai Yang school of Information and Control engineering China University of Mining and TechnologyXuzhou 221116China

Crocodiles,one of the oldest and most resilient species on Earth,have demonstrated remarkable locomotor abilities both on land and in water,evolving over millennia to adapt to diverse *** this study,we draw inspiration from crocodiles and design a highly biomimetic crocodile robot equipped with multiple degrees of freedom and articulated trunk *** design is based on comprehensive analysis of the structural and motion characteristics of real *** bionic crocodile robot has a problem of limb-torso incoordination during *** solve this problem,we used the D-H method for both forward and inverse kinematics analysis of the robot's legs and *** a series of simulation experiments,we investigated the robot's motion stability,fault tolerance,and adaptability to environments in two motor patterns:with and without spine and tail *** experimental results show that the bionic crocodile robot exhibits superior motion performance when the spine and tail cooperate with the *** study not only demonstrates the potential of biomimicry in robotics but also underscores the significance of understanding how nature's designs can inform and enhance technological innovations.

关键词： Bionic crocodile robot Kinematic modeling Motion simulation Multipart coordination

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Effects of oxygen vacancy on bond ionicity,lattice energy,and microwave dielectric properties of CeO_(2) ceramics with Yb^(3+) substitution

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Journal of Advanced Ceramics 2024年第2期13卷 247-254页

作者： Mingan Shi Shuyang Ma Wangsuo Xia Ying Wang Jinzi Yu Haitao Wu school of Materials Science and Physics China University of Mining and TechnologyXuzhou 221008China school of Environment and Material engineering Yantai UniversityYantai 264005China

Novel Yb_(x)Ce_(1-x)O_(2-0.5x)(x=0-0.8)ceramics,designed by replacing Ce^(4+)with Yb^(3+)ions were prepared by conventional oxide reaction,and the structural stability of the cubic fluorite structure was assessed using lattice energy and ionic properties of Ce/Yb-O *** oxygen vacancy caused by unequal substitution,which played a decisive role in bond ionicity and lattice energy,was analyzed experimentally by XPS and also theoretically by first *** Yb_(x)Ce_(1-x)O_(2-0.5x) ceramics maintain a stable cubic fluorite structure when x≤0.47,corresponding to the minimum lattice energy of 4142 kJ/mol with the lowest ionicity as ƒ_(i)=87.57%.For microwave dielectric properties,when the Yb_(x)Ce_(1-x)O_(2-0.5x)(x=0-0.4)ceramics are pure phase,the porosity-corrected permittivity is dependent on the bond *** Q×ƒ values are related to the lattice energy and grain *** temperature coefficient of resonance frequency has been analyzed using bond *** the Yb_(x)Ce_(1-x)O_(2-0.5x)(x=0.5-0.8)ceramics are multiple phases,the microwave dielectric properties are associated with the phase composition and grain growth.

关键词： structure stability bond ionicity oxygen vacancy electronic localization function(ELF)

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Predicting microseismic,acoustic emission and electromagnetic radiation data using neural networks

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Journal of Rock Mechanics and Geotechnical engineering 2024年第2期16卷 616-629页

作者： Yangyang Di Enyuan Wang Zhonghui Li Xiaofei Liu Tao Huang Jiajie Yao school of Materials engineering Changshu Institute of TechnologySuzhou215506China Key Laboratory of Gas and Fire Control for Coal Mines(China University of mining and Technology) Ministry of EducationXuzhou221116China school of Safety engineering China University of Mining and TechnologyXuzhou221116China State Key Laboratory of Coal Resources and Safe mining China University of Mining and TechnologyXuzhou221116China

Microseism,acoustic emission and electromagnetic radiation(M-A-E)data are usually used for predicting rockburst ***,it is a great challenge to realize the prediction of M-A-E *** this study,with the aid of a deep learning algorithm,a new method for the prediction of M-A-E data is *** this method,an M-A-E data prediction model is built based on a variety of neural networks after analyzing numerous M-A-E data,and then the M-A-E data can be *** predicted results are highly correlated with the real data collected in the *** field verification,the deep learning-based prediction method of M-A-E data provides quantitative prediction data for rockburst monitoring.

关键词： Microseism Acoustic emission Electromagnetic radiation Neural networks Deep learning Rockburst

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Instability mechanism of mining roadway passing through fault at different angles in kilometre-deep mine and control measures of roof cutting and NPR cables

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Journal of Mountain Science 2024年第1期21卷 236-251页

作者： SUN Xiaoming WANG Jian ZHAO Wenchao MING Jiang ZHANG Yong LI Zhihu MIAO Chengyu GUO Zhibiao HE Manchao State Key Laboratory for Geomechanics and Deep Underground engineering China University of Mining and Technology(Beijing)Beijing 100083China school of Mechanics and Civil engineering China University of Mining and Technology(Beijing)Beijing 100083China

The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and field experiments in the context of the Daqiang coal mine located in Shenyang, China. The stability control countermeasure of "pre-splitting cutting roof + NPR anchor cable"(PSCR-NPR) is simultaneously proposed. According to the different deformation characteristics of the roadway, the faults are innovatively classified into three types, with α of type I being 0°-30°, α of type II being 30°-60°, and α of type III being 60°-90°. The full-cycle stress evolution paths during mining roadway traverses across different types of faults are investigated by numerical simulation. Different pinch angles α lead to high stress concentration areas at different locations in the surrounding rock. The non-uniform stress field formed in the shallow surrounding rock is an important reason for the instability of the roadway. The pre-cracked cut top shifted the high stress region to the deep rock mass and formed a low stress region in the shallow rock mass. The high prestressing NPR anchor cable transforms the non-uniform stress field of the shallow surrounding rock into a uniform stress field. PSCR-NPR is applied in the fault-through roadway of Daqiang mine. The low stress area of the surrounding rock was enlarged by 3-7 times, and the cumulative convergence was reduced by 45%-50%. It provides a reference for the stability control of the deep fault-through mining roadway.

关键词： Kilometre-deep mine Fault mining roadway Failure mechanism Pre-splitting cutting roof High pre-stress NPR anchor cable

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A whole process damage constitutive model for layered sandstone under uniaxial compression based on Logistic function

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Journal of Central South University 2024年第7期31卷 2411-2430页

作者： LIU Dong-qiao GUO Yun-peng LING Kai LI Jie-yu State Key Laboratory for Geomechanics and Deep Underground engineering China University of Mining and Technology-BeijingBeijing 100083China school of Mechanics and Civil engineering China University of Mining and Technology-BeijingBeijing 100083China

Bedding structural planes significantly influence the mechanical properties and stability of engineering rock *** study conducts uniaxial compression tests on layered sandstone with various bedding angles(0°,15°,30°,45°,60°,75°and 90°)to explore the impact of bedding angle on the deformational mechanical response,failure mode,and damage evolution processes of *** develops a damage model based on the Logistic equation derived from the modulus’s degradation considering the combined effect of the sandstone bedding dip angle and *** model is employed to study the damage accumulation state and its evolution within the layered rock *** research also introduces a piecewise constitutive model that considers the initial compaction characteristics to simulate the whole deformation process of layered sandstone under uniaxial *** results revealed that as the bedding angle increases from 0°to 90°,the uniaxial compressive strength and elastic modulus of layered sandstone significantly decrease,slightly increase,and then decline *** corresponding failure modes transition from splitting tensile failure to slipping shear failure and back to splitting tensile *** indicated by the modulus’s degradation,the damage characteristics can be categorized into four stages:initial no damage,damage initiation,damage acceleration,and damage deceleration *** theoretical damage model based on the Logistic equation effectively simulates and predicts the entire damage evolution ***,the theoretical constitutive model curves closely align with the actual stress−strain curves of layered sandstone under uniaxial *** introduced constitutive model is concise,with fewer parameters,a straightforward parameter determination process,and a clear physical *** study offers valuable insights into the theory of layered rock mechanics and holds implications for ensuring the safety of rock engineering.

关键词： layered sandstone uniaxial compression damage evolution Logistic function constitutive model

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Experimental study on the effect of water absorption level on rockburst occurrence of sandstone

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Journal of Rock Mechanics and Geotechnical engineering 2024年第1期16卷 136-152页

作者： Dongqiao Liu Jie Sun Pengfei He Manchao He Binghao Cao Yuanyuan Yang State Key Laboratory for Geomechanics and Deep Underground engineering China University of Mining and Technology(Beijing)Beijing100083China school of Mechanics and Civil engineering China University of Mining and Technology(Beijing)Beijing100083China Institute for Deep Underground Science and engineering China University of Mining and Technology(Beijing)Beijing100083China

To investigate the mechanism of rockburst prevention by spraying water onto the surrounding rocks,15 experiments are performed considering different water absorption levels on a single ***-speed photography and acoustic emission(AE)system are used to monitor the rockburst *** effect of water on sandstone rockburst and the prevention mechanism of water on sandstone rockburst are analyzed from the perspective of energy and failure *** results show that the higher the ab-sorption degree,the lower the intensity of the rockburst after absorbing water on single side of *** is reflected in the fact that with the increase in the water absorption level,the ejection velocity of rockburst fragments is smaller,the depth of the rockburst pit is shallower,and the AE energy is *** the water absorption level of 100%,the magnitude of rockburst intensity changes from medium to *** prevention mechanism of water on sandstone rockburst is that water reduces the capacity of sandstone to store strain energy and accelerates the expansion of shear cracks,which is not conducive to the occurrence of plate cracking before rockburst,and destroys the conditions for rockburst incubation.

关键词： Rockburst Water Prevention effect Crack evolution

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An improved strain-softening constitutive model of granite considering the effect of crack deformation

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Journal of Rock Mechanics and Geotechnical engineering 2024年第4期16卷 1202-1215页

作者： Yapeng Li Qiang Zhang Qiuxin Gu Peinan Wu Binsong Jiang State Key Laboratory for Geomechanics and Deep Underground engineering School of Mechanics and Civil EngineeringChina University of Mining and TechnologyXuzhou221116China

This paper presents an improved strain-softening constitutive model considering the effect of crack deformation based on the triaxial cyclic loading and unloading test *** improved model assumes that total strain is a combination of plastic,elastic,and crack *** constitutive relationship between the crack strain and the stress was further *** evolutions of mechanical parameters,*** parameters,dilation angle,unloading elastic modulus,and deformation parameters of crack,with the plastic strain and confining pressure were *** the increase in plastic strain,the cohesion,friction angle,dilation angle,and crack Poisson's ratio initially increase and subsequently decrease,and the unloading elastic modulus and the crack elastic modulus nonlinearly *** increasing confining pressure enhances the strength and unloading elastic modulus,and decreases the dilation angle and Poisson's ratio of the *** theoretical triaxial compressive stress-strain curves were compared with the experimental results,and they present a good agreement with each *** improved constitutive model can well reflect the nonlinear mechanical behavior of granite.

关键词： Strain-softening Crack deformation effect Plastic shear strain Constitutive model

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ZIF-8-functionalized polymer electrolyte with enhanced performance for high-temperature solid-state lithium metal batteries

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Rare Metals 2024年第3期43卷 984-994页

作者： Jin-Fang Zhang Yuan-Yuan Wang Xiao-Feng Li Gen-Yan Zhang Ying Li Rong Liu Sheng-Liang Hu Tuo-Ping Hu Ruth Knibbe Qing-Bing Xia school of Materials Science and engineering North University of ChinaTaiyuan030051China school of Energy and Power engineering North University of ChinaTaiyuan030051China school of Chemistry and Chemical engineering North University of ChinaTaiyuan030051China school of Mechanical and mining engineering The University of QueenslandBrisbaneQLD4072Australia

Solid polymer electrolytes(SPEs)with high ionic conductivity are desirable for solid-state lithium metal batteries(SSLMBs)to achieve enhanced safety and energy *** nanofillers into a polymeric matrix to develop nanocomposite solid electrolytes(NCSEs)has become a promising method for improving the ionic conductivity of the ***,a novel ZIF-8-functionalized NCSE was prepared for high-temperature S SLMB s using an in situ radical polymerization *** is found that the ZIF-8 nanoparticles could reduce the crystallinity of polymer segments and offer a Lewis acid surface that promotes the dissociation of lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)and stabilizes the TFSI^(-) anion ***,the as-prepared NCSE exhibits an outstanding ionic conductivity of 1.63×10^(-3)S·cm^(-1),an electrochem ical stability window of 5.0 V at 80℃,and excellent interface compatibility with lithium metal anode with a stable polarization over 2000 ***,the assembled SSLMBs with LiFePO_(4)cathode show dendrite-free Li-metal surface,good rate capability,and stable cycling stability with a capacity retention of 70%over 1000 cycles at a high temperature of 80℃.This work provides valuable insights into promoting the ionic conductivity of SPEs.

关键词： Lithium metal batteries Metal-organic frameworks Solid polymer electrolytes Lithium metal anode Interfacial compatibility

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