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Investigation of stress-induced progressive failure of mine pillars using a Voronoi grain-based breakable block model

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International Journal of Mining Science and Technology 2024年第5期34卷 713-729页

作者： Shili Qiu Shirui zhang Quan Jiang Shaojun Li Hao zhang Qiankuan Wang State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China university of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The Voronoi grain-based breakable block model(VGBBM)based on the combined finite-discrete element method(FDEM)was proposed to explicitly characterize the failure mechanism and predict the deformation behavior of hard-rock mine *** influence of the microscopic parameters on the macroscopic mechanical behavior was investigated using laboratory-scale *** field-scale pillar models(width-to-height,W/H=1,2.and 3)were calibrated based on the empirically predicted stress-strain curves of Creighton mine *** results indicated that as the W/H ratios increased,the VGBBM effectively predicted the transition from strain-softening to pseudo-ductile behavior in pillars,and explicitly captured the separated rock slabs and the V-shaped damage zones on both sides of pillars and conjugate shear bands in core zones of *** volumetric strain field revealed significant compressional deformation in core zones of *** the peak strains of W/H=1 and 2.pillars were relatively consistent,there were significant differences in the strain energy storage and release mechanism.W/H was the primary factor influencing the deformation and strain energy in the pillar *** friction coefficient of the structural plane was also an important factor affecting the pillar strength and the weakest discontinuity *** fracture surface was controlled by the discontinuity angle and the friction *** study demonstrated the capability of the VGBBM in predicting the strengths and deformation behavior of hard-rock pillars in deep mine design.

关键词： Pillar strength FDEM Voronoi tessellation Spalling Bulking

Fast-response,high-sensitivity multi-modal tactile sensors based on PPy/Ti_(3)C_(2.T_(x) films for multifunctional applications

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Nano Research 2024年第5期17卷 4410-4419页

作者： Guangshuai Xi Dongzhi zhang Mingcong Tang Hao zhang Yuehang Sun Yubiao zhang Haolin Cai Hui Xia Dandi Zhou College of Control Science and Engineering China University of Petroleum(East China)Qingdao 266580China

In recent years,multi-modal flexible tactile sensors have become an important direction in the development of electronic skin because of their excellent sensitivity,flexibility and wearable *** this work,a humidity-pressure multi-modal flexible sensor based on polypyrrole(PPy)/Ti_(3)C_(2.T_(x) sensitive film packaged with porous polydimethylsiloxane(PDMS)is investigated by combining the sensitive structure generation mechanism of in situ polymerization to achieve the simultaneous detection of humidity and pressure,which has a sensitivity of 89,113.4Ω/%RH in a large humidity range of 0%-97%RH,and response/recovery time of 2.5/1.9 *** tactile pressure sensing has a high sensitivity,a fast response of 67/52.ms,and a wide detection *** device also has excellent performance in terms of stability and repeatability,making it promising for respiratory pattern and motion *** work provides a new solution to address the construction of multi-modal tactile sensors with potential applications in the fields of medical health,epidemic prevention.

关键词： multi-modal sensors humidity-pressure tactile sensors resistive sensors Ti3C2.x human respiratory and motion detection

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甲基萘烷基化催化剂积炭的烧炭研究

燃料化学学报 2004年第2期32卷 249-252页

作者：白雪峰李琪刘宁生胡浩权大连理工大学化工学院辽宁大连116012 哈尔滨工程大学化工学院黑龙江哈尔滨150001 黑龙江省石油化学研究院黑龙江哈尔滨150040

The alkylation of methylnaphthalene and methanol was carried out on HZSM-5 zeolite catalyst. The characteristics of coke deposited on the catalysts under the atmospheric pressure or supercritical fluid condition were found out and coke-burning reaction apparent activation energies of the used catalysts were calculated by using the thermo gravimetric analysis technique. The results showed that compared to the catalyst used at the atmospheric pressure, coke deposition was greatly depressed and life of catalysts increased 10 times under the supercritical fluid reaction condition. The coke-burning reaction of the used catalysts mainly happened at temperature range of 42.?℃ to 580?℃. The longer reaction time led to higher peak temperature of weight loss and to greater coke-burning reaction apparent activationenergies of the used catalysts.

关键词：甲基萘烷基化烧炭 HZSM-5 超临界

Physics-based seismic analysis of ancient wood structure:fault-to-structure simulation

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 727-740页

作者： Ba Zhenning Fu Jisai Wang Fangbo Liang Jianwen zhang Bin zhang Long State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation (Tianjin University)Tianjin 300350China school of Civil Engineering Tianjin UniversityTianjin 300350China Administrative Office of the Summer Palace Beijing 100091China school of Architecture Tianjin UniversityTianjin 300072China

Based on the domain reduction method,this study employs an SEM-FEM hybrid workflow which integrates the advantages of the spectral element method(SEM)for flexible and highly efficient simulation of seismic wave propagation in a three-dimensional(3D)regional-scale geophysics model and the finite element method(FEM)for fine simulation of structural response including soil-structure interaction,and performs a physics-based simulation from initial fault rupture on an ancient wood *** verification of the hybrid workflow,a large-scale model of an ancient wood structure in the Beijing area,The Tower of Buddhist Incense,is established and its responses under the 1665 Tongxian earthquake and the 1730 Yiheyuan earthquake are *** results from the simulated ground motion and seismic response of the wood structure under the two earthquakes demonstrate that this hybrid workflow can be employed to efficiently provide insight into the relationships between geophysical parameters and the structural response,and is of great significance toward accurate input for seismic simulation of structures under specific site and fault conditions.

关键词： spectral element method finite element method fault-to-structure simulation physical model domain reduction method

Bioinspired Scraper-File Type Frequency-Doubling Ultrasonic Exciter

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Journal of Bionic Engineering 2024年第4期21卷 1801-1816页

作者： Wenshuai Wu Mingshuo zhang Zeming Li Guang Yao Xinggang Jiang Deyuan zhang school of Mechanical Engineering and Automation Beihang UniversityBeijing100191China Institute of Bionic and Micro-Nano Systems Beihang UniversityBeijing100191China Guangdong Provincial Key Laboratory of Minimally Invasive Surgical Instruments and Manufacturing Technology Guangdong University of TechnologyGuangzhou510006China

In the natural world,leaf-cutting ants cause vibrations through their mutual scraping of file-scraper *** this study,we designed a Biomimetic Ultrasonic Exciter(BUE)that imitates leaf-cutting *** operating characteristics of the BUE were studied through experimental testing and finite element *** results showed that the BUE could generate stable ultrasonic vibrations,and that the excitation frequency only needed to be half the Output Frequency(OF).This frequency-doubling phenomenon was conducive to achieving BUE *** further explore the phenomenon of frequency-doubling vibration output,this study designed scrapers of five different sizes,conducted excitation and first-order natural frequency measurement tests,and the corresponding finite element *** was found that each scraper could operate in frequency-doubling mode,but the operating frequency and natural mode frequencies did not correspond with one *** further explicate experimental and simulation results,a two-degrees-of-freedom vibration model was *** was evident that the contact relationship between the dentate disc and scraper introduced strong nonlinear factors into the system,accounting for the frequency-doubling phenomenon and the difference between the BUE’s operating and mode *** BUE could be expected to facilitate the production of high-power micro-ultrasonic generators and has potential application value in the fields of mechanical processing,industrial production,and medical health.

关键词： Leaf-cutting ants Power ultrasound Nonlinear vibration Ultrasonic scalpel Micro vibrator

Experimental Study on Explosibility of Pulverized Bituminous Coal

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Experimental Study on Explosibility of Pulverized Bituminous...

Research on Logistic Alliance Stability Based on Rough Sets and Grey Theory

2.04安全科学与技术国际会议

作者： zhang Jianhua & GUO Jin (school of Resource and Environment Engineering {{2. university of Technology {{2. 430070 Hubei china)

The explosibility of 3 types of bituminous coal fines, which are made of the coal samples gathered respectively from Pingdingshan Coal Mine, Henan province, Hancheng Coal Mine, Shaanxi province and Ta

关键词： dust explosion hartmamn bomb, bituminous coal fines, pulverized coal coal pulverizing systems

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Research on Logistic Alliance Stability Based on Rough Sets ...

THE STRUCTURE OF INVERTIBLE SUBSTITUTIONS ON A THREE-LETTER ALPHABET

2.10 Second ETP/IITA World Congress in Applied Computing, computer Science, and computer Engineering(ACC 2.10)

作者： DONG HUIZHONG1 SHI CHENGDONG2.1. Management school {2. school of Electric and Electronic Engineering Shandong{2. of Technology No.1{2. zhangzhou Road, zhangdian District, Zibo City, Shandong Province {2.5049 china

The article established a kind of stability evaluation attribute model of the Logistic alliance, and then, put forward a logistic alliance stability evaluation model framework by utilizing rough sets and grey theory. A heuristic attribute reduction algorithm based on discernable matrix was set up in order to optimize attributes. The status of the logistic alliance stability was assessed through an example. The result shows: Combining rough sets and grey evaluation, the model of logistic alliance provides a quantitative analysis channel of the logistics alliance stability, so as to provide decision making basis for coordinating development and safeguarding stability of the alliance.

关键词： Rough sets Grey theory Discernable matrix Logistic alliance Stability

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Analysis in Theory and Applications 2003年第4期19卷 365-382页

作者： Tan Bo Wen Zhixiong zhang Yiping (wuhan{{2.,china) wuhan university China

We study the structure of invertible substitutions on three-letter alphabet. We show that there exists a finite set S of invertible substitutions such that any invertible substitution can be written as I wσ 1σ 2.…σ k,where I w is the inner automorphism associated with w, and σ j∈ S for 1≤j≤k. As a consequence,M is the matrix of an invertible substitution if and only if it is a finite product of non-negative elementary matrices.

关键词： invertible substitution indecomposable substitution combinatorics of words

Maneuvering Prediction and Simulation of Immersed Tunnel Cube

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武汉理工大学学报（交通科学与工程版） 1999年第S1期24卷 109-114页

作者： Xiaotu zhang Lewen zhang Zuyuan Liu ({{2. Transportation university, {2. 430063, P.R.china)

In this paper, the transportation mode of tube during the immersed tunnel engineering in Yangtze River incorporated, mathematical models of the combination of the tube and four barges are established when it is towed by a tugboat through an elastic rope and pushed by two pushers. Based on evaluating the hydrodynamic derivatives by regressive formula, the simulations and analysis of the whole maneuvering motion course are accomplished. They include sway and yaw motion simulation of the combination and prediction of maneuvering motion such as turning circles of different rudder angle under the condition of being pushed by two pushers. The coincidence of the prediction with the results of model test is good.

关键词： immersed tunnel engineering maneuvering prediction sway and yaw motion simulation