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Synthesis and characterization of SrCe_(0.95)Y_(0.05)O_(3-δ) nano powders by low temperature combustion

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Rare Metals 2006年第1期25卷 79-83页

作者： meng bo TAN Xiaoyao ZHANG Baoyan YANG Naitao College of Chemical Engineering and Technology Shandong University of Technology Zibo 255049 China College of Science Northeastern University Shenyang 110004 China

Nanosized SrCe0.95Y0.05O3-δ powders with homogeneous composition were synthesized by the low temperature combustion process based on the Pechini method. A polymeric precursor sol was formed by using citric acid and ethylene glycol as the chelating agents of metal ions. The perovskite-type SrCe0.95Y0.05O3-δpowders with uniform shape and smaller than 25 nm in size were obtained through the combustion of the polymeric precursor sol at the existence of nitric acid and ammonium hydroxide. It was found that modulating the quantifies of nitric acid and ammonium hydroxide could control the particle size, and the quantities of residue carbonate ions were also affected by the quantifies of citric acid and ethylene glycol.

关键词： inorganic nonmetal material perovskite-type oxides SrCe0.95Y0.05O3-δ combustion synthesis

Unlocking multidirectional and broadband wind energy harvesting with triboelectric nanogenerator and vortex-induced vibration of sphere

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 1895-1912页

作者： Lanbin ZHANG Yixiang HE bo meng Huliang DAI Lin WANG Faculty of Engineering China University of GeosciencesWuhan430074China International Joint Research Center for Deep Earth Drilling and Resource Development Wuhan430074China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment School of Aerospace EngineeringHuazhong University of Science and TechnologyWuhan430074China Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhenGuangdong Province518060China

A unique oscillating wind-driven triboelectric nanogenerator(OWTENG)based on the sphere's vortex-induced vibration(VIV)behavior is proposed in this study,which can harvest wind energy across a multitude of horizontal *** the Euler-Lagrange method,the coupled governing equations of the OWTENG are established and subsequently validated by experimental *** vibrational properties and output performance of the OWTENG for varying wind speeds are analyzed,demonstrating its effectiveness in capturing wind energy across a broad range of wind speeds(from 2.20 m/s to 8.84 m/s),and the OWTENG achieves its peak output power of 106.3μW at a wind speed of 5.72 m/***,the OWTENG maintains a steady output power across various wind directions within the speed range of 2.20 m/s to 7.63 m/***,when the wind speed exceeds 7.63 m/s,the vibrational characteristics of the sphere shift based on the wind direction,leading to fluctuations in the OWTENG's output *** research presents an innovative approach for designing vibrational triboelectric nanogenerators,offering valuable insights into harvesting wind energy from diverse directions and speeds.

关键词： wind energy harvesting triboelectric nanogenerator vortex-induced vibration(VIV) lock-in region

Adaptive sliding mode output tracking control based-FODOB for a class of uncertain fractional-order nonlinear time-delayed systems

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Science China(Technological Sciences) 2020年第9期63卷 1854-1862页

作者： WANG Zhen WANG XinHe XIA JianWei SHEN Hao meng bo College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao266590China School of Mathematics Science Liaocheng UniversityLiaocheng252059China School of Electrical Engineering and Information Anhui University of TechnologyMaanshan243002China

An adaptive sliding mode control(ASMC) method, based on fractional-order disturbance-observer(FODOB), is presented for a class of fractional-order nonlinear time-delay systems(FONTDS) with uncertainties to solve the target output tracking *** external disturbances are estimated by FODOB, and the unknown internal perturbations of the system are adaptively estimated by sliding mode control(SMC). Furthermore, Gronwall's inequality approach is used to ensure that the output tracking error is uniformly bounded for FONTDS. Firstly, a fractional-order sliding mode control(FOSMC) based FODOB is proposed for a fractional-order linear time-delay system(FOLTDS). Secondly, combined with adaptive estimation, the ASMC of FONTDS is studied. Finally, a numerical example of FONTDS is used to verify the effectiveness of the proposed methods.

关键词： adaptive sliding mode control fractional-order disturbance-observer time-delay uncertainty

Stress evolution and support mechanism of a bolt anchored in a rock mass with a weak interlayer

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International Journal of Mining Science and Technology 2017年第3期27卷 573-580页

作者： Ding Shuxue Jing Hongwen Chen Kunfu Xu Guo'an meng bo State Key Laboratory for Geomechanics & Deep Underground Engineering School of Mechanics and Civil Engineering China University of Mining & Technology Xuzhou 221116 China

By applying experimental method, the bolt stress and supporting mechanism is studied during the deformation process of a rock mass containing a weak interlayer. The force measuring bolt is installed manually and instrumented five pairs of symmetrical strain gauges. The experimental results show that the fully grouted bolt suffers tensile, compressive, bending and shear stress at the same time. The bolt stress evolution is closely related to the deformation stages of the rock mass which are very gradually varying stage, gradually varying stage at the pre-peak and suddenly varying stage at the post peak *** axial compressive stress in the bolt is mainly induced by the moment. Thus, in most cases the axial compressive stress is distributed on one side of the bolt. For axial stresses, induced by the axial force and the bending moment at the post-peak stage, three types of changing are observed, viz. increasingincreasing type, decreasing-increasing type and increasing-decreasing type. The stress characteristics of the bolt section in the weak interlayer are significantly different from those in the hard rock. The failure models of the anchored bolt are tensile failure and shear failure, respectively. The bolt not only provides constraints on the free surface of the rock mass, but also resists the axial and lateral loading by the bending moment. This study provides valuable guidelines for bolting support design and its safety assessment.

关键词： Fully grouted bolt Stress evolution Support mechanism Weak interlayer Deformation process

Output regulation of nonaffine nonlinear systems using singular perturbation theory

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控制理论与应用（英文版） 2009年第2期7卷 181-184页

作者： bo meng Yuanwei JING, Xiaoping LIU College of Information Science and Engineering Northeastern University Shenyang Liaoning 110004 China

A control synthesis method for output regulation based on singular perturbation theory combined with inverting design is considered for a class of nonaffine nonlinear systems. The resulting control signal is defined as a solution to ＂fast＂ dynamics which inverts a series error model, whose state is exponentially stable. It is shown that, under sufficient conditions being consistent with the assumptions of singular perturbation theory, this problem is solvable with （ε） tracking error if and only if a set of first-order nonlinear partial differential equations are solvable. The control law can be easily constructed and the simulations show the feasibility and effectiveness of the controller.

关键词： Output regulation Singular perturbation Nonaffine nonlinear system Dynamic inversion

Preparation of electrolyte membranes for micro tubular solid oxide fuel cells

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Science China Chemistry 2008年第9期51卷 808-812页

作者： TAN XiaoYao YIN WeiNing meng bo meng XiuXia YANG NaiTao MA ZiFeng School of Chemical Engineering Shandong University of TechnologyZibo 255049China Department of Chemical Engineering Shanghai Jiaotong UniversityShanghai 200240China

Yttria-stabilized zirconia (YSZ) micro tubular electrolyte membranes for solid oxide fuel cells (SOFCs) were prepared via the combined wet phase inversion and sintering technique. The as-derived YSZ mi- cro tubes consist of a thin dense skin layer and a thick porous layer that can serve as the electrode of fuel cells. The dense and the porous electrolyte layers have the thickness of 3-5 μm and 70-90 μm, respectively, while the inner surface porosity of the porous layer is higher than 28.1%. The two layers are perfectly integrated together to preclude the crack or flake of electrolyte film from the electrode. The presented method possesses distinct advantages such as technological simplicity, low cost and high reliability, and thus provides a new route for the preparation of micro tubular SOFCs.

关键词： solid oxide fuel cell micro tube yttrium stabilized zirconia (YSZ) phase inversion

Comparative Detection of Calcium Fluctuations in Single Female Sex Cells of Tobacco to Distinguish Calcium Signals Triggered by in vitro Fertilization

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Journal of Integrative Plant Biology 2009年第8期51卷 782-791页

作者： Xiong-bo Peng meng-Xiang Sun Hong-Yuan Yang Key Laboratory of Ministry of Education for Plant Developmental Biology College of Life Sciences Wuhan University Wuhan 430072 China

Double fertilization is a key process of sexual reproduction in higher plants. The role of calcium in the activation of female sex cells through fertilization has recently received a great deal of attention. The establishment of a Ca^2＋-imaging technique for living, single, female sex cells is a difficult but necessary prerequisite for evaluating the role of Ca^2＋ in the transduction of external stimuli, including the fusion with the sperm cell, to internal cellular processes. The present study describes the use of Fluo-3 for reporting the Ca^2＋ signal in isolated, single, female sex cells, egg cells and central cells, of tobacco plants. A suitable loading protocol was optimized by loading the cells at pH 5.6 with 2 μM Fluo-3 for 30 min at 30 ℃. Under these conditions, several key factors related to in vitro fertilization were also investigated in order to test their possible effects on the [Ca^2＋]cyt of the female sex cells. The results indicated that the bovine serum albumin-fusion system was superior to the polyethlene glycol-fusion system for detecting calcium fluctuations in female sex cells during fertilization. The central cell was fertilized with the sperm cell in bovine serum albumin; however, no evident calcium dynamic was detected, implying that a transient calcium rise might be a specific signal for egg cell fertilization.

关键词： cytosolic calcium fertilization Fluo-3 sex cells

On the rumpling mechanism in nanocrystalline coatings:Improved by reactive magnetron sputtering with oxygen

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Journal of Materials Science & Technology 2023年第1期132卷 69-80页

作者： bo meng Jinlong Wang Lanlan Yang Minghui Chen Shenglong Zhu Fuhui Wang Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang 110819China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

Surface rumpling is detrimental to high temperature protective coatings as it shortens their lifetime and leads to adhesion losses and unexpected corrosion *** driving force and mass transport mechanism behind of rumpling remains to be *** the present investigation,we subjected two types of nanocrystalline coating systems to avoid the influence of interdiffusion on rumpling *** group was an ordinary nanocrystalline coating,and the other group was designed and prepared with trace oxygen by reactive magnetron *** cyclic oxidation test at 1100°C was also car-ried *** show the ordinary nanocrystalline coating oxidized rapidly,which leads to the fast consumption of Al and the acceleration of phase transition in the ***,severe surface rumpling is observed due to the stress release of nanocrystals through plastic ***,the reactive doping of oxygen can significantly reduce the consumption process of Al in nanocrystalline *** rumpling is controlled due to the improvement of coefficient of thermal expansion and Young’s modulus of the ***,the cyclic oxidation resistance is improved.

关键词： High temperature oxidation Thermal cycling oxidation Surface rumpling Nanocrystalline coating Residual stress

Master event based backazimuth estimation and its application to downhole microseismic monitoring

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Petroleum Science 2022年第6期19卷 2675-2682页

作者： Xiao-bo meng Hai-Chao Chen Feng-Lin Niu Yi-Jing Du Department of Geophysics Chengdu University of TechnologyChengduSichuan610059China Unconventional Petroleum Research Institute and State Key Laboratory of Petroleum Resources and ProspectingChina University of PetroleumBeijing102249China Department of Earth Environmental and Planetary SciencesRice UniversityHoustonTX77005USA Petro China Research Institute of Petroleum Exploration and Development Beijing100083China

Microseismic monitoring provides a valuable tool for evaluating the effectiveness of hydraulic fracturing ***,robust detection and accurate location of microseismic events are challenging due to the low signal to noise ratio(SNR)of their signals on *** a downhole monitoring setting,P-wave polarization direction measured from 3-component records is usually considered as the backazimuth of the microseismic event,i.e.,the direction of the *** direction and arrival time difference between the P and S waves is used to locate the seismic *** SNR is low,an accurate estimate of event backazimuth becomes very challenging with the traditional covariance matrix *** we propose to employ a master event and use a grid search method to find the backazimuth of a target event that maximizes the dot product of the two backazimuthal vectors of the master and target *** compared the backazimuths measured with the proposed grid-search and the conventional covariance-matrix methods using a large synthetic *** found that the grid-search method yields more accurate backazimuth estimates from low SNR records when measurements are made at single geophone *** array data are combined,the proposed method also has some advantage over the covariance-matrix method,especially when the number of geophones is *** also applied the method to a microseismic dataset acquired by a hydraulic fracturing project at a shale play site in southwestern China and found that the relocated microseismic events tend to align along existing faults more tightly than those in the original catalog.

关键词： Hydraulic fracturing Microseismic event Back azimuth Master event Grid search Covariance-matrix