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Science China(Physics,Mechanics & Astronomy) 2020年第4期63卷 108-118页

作者： YanWei Liu YueGuang Wei hao long Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China

The indentation technique is widely used in measuring the mechanical properties of soft matter at the microscale or nanoscale,but still faces challenges by these unique properties as well as the consequent strong surface adhesion, including the strong nonlinear effect, unclear judgment of the contact point, difficulties in estimating the contact area, and the risk of the indenter piercing the sample. Here we propose a two-step method to solve these problems: lay a hard film on a soft matter, and obtain the viscoelastic properties of this soft matter through the indentation response of this composite structure. We first establish a theoretical indentation model of the hard film-soft substrate system based on the theory of plates, elastic-viscoelastic correspondence principle and Boltzmann superposition principle. To verify the correctness of this method, we measure the mechanical properties of the methyl vinyl silicone rubber(MVSR) covered by a Cu nanofilm. Finally, we test the effectiveness and error sensitivity of this method with the finite element method(FEM). The results show that our method can accurately measure the mechanical properties of soft matter, while effectively circumventing the problems of the traditional indentation technique.

关键词： viscoelastic properties soft matter theoretical indentation model indentation technique finite element method

Phase composition, morphology and element contents of micro-arc oxidation ceramic coatings on Ti–6Al–4V alloy under different calcination conditions

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Rare Metals 2016年第11期35卷 836-840页

作者： Guo-Dong hao Xue-long hao Zu-Fang Zhu Department of Chemistry Mudanjiang Normal University National Center of Analysis and Testing for Nonferrous Metals and Electronic Materials General Research Institute for Nonferrous Metals

Compound ceramic coatings with the main crystalline of Al_2TiO_5（in the as-prepared coating without treatment） were prepared in situ on the surface Ti-6Al-4V alloy by means of pulsed bipolar micro-arc oxidation in Na AlO_2 solution. For the purpose of studying the antioxidation properties of the samples, the coated samples treated in argon and the as-coated samples were calcined in air at 1000 °C. And the related characteristics were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and X-ray fluorescence（XRF） spectroscopy, respectively. The results show that, when it was calcined in air for 1 h, Al_2TiO_5in the as-prepared coating decomposed and transformed into α-Al_2O_3 and rutile TiO_***, after almost 4 h in argon, Al_2TiO_5in the asprepared coating decomposed and the final coating surface contents are completely α-Al_2O_3, and those of the middle interface are mainly Al_2O_3 and Ti_2O_3. The morphologies of the coatings after calcination in argon and air are ***-temperature oxidation occurred violently in the alloy substrate without coatings. Furthermore, the weight gain curves of the as-prepared samples and the coated samples treated in argon both show a parabolic shape.

关键词： Micro-arc oxidation Ti-6AI-4V Argon High-temperature oxidation

Controller area network node reliability assessment based on observable node information

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Frontiers of Information Technology & Electronic Engineering 2017年第5期18卷 615-626页

作者： Lei-ming ZHANG long-hao TANG Yong LEI State Key Laboratory of Fluid Power Transmission and Mechatronics Zhejiang UniversityHangzhou 310027China

Controller area network(CAN) based fieldbus technologies have been widely used in networked manufacturing systems. As the information channel of the system, the reliability of the network is crucial to the system throughput, product quality, and work crew safety. However, due to the inaccessibility of the nodes' internal states, direct assessment of the reliability of CAN nodes using the nodes' internal error counters is infeasible. In this paper, a novel CAN node reliability assessment method, which uses node's time to bus-off as the reliability measure, is proposed. The method estimates the transmit error counter(TEC) of any node in the network based on the network error log and the information provided by the observable nodes whose error counters are ***, a node TEC estimation model is established based on segmented Markov chains. It considers the sparseness of the distribution of the CAN network errors. Second, by learning the differences between the model estimates and the actual values from the observable node, a Bayesian network is developed for the estimation updating mechanism of the observable nodes. Then, this estimation updating mechanism is transferred to general CAN nodes with no TEC value accessibility to update the TEC estimation. Finally, a node reliability assessment method is developed to predict the time to reach bus-off state of the nodes. Case studies are carried out to demonstrate the effectiveness of the proposed methodology. Experimental results show that the estimates using the proposed model agree well with actual observations.

关键词： Controller area network(CAN) Transmit error counter(TEC) TEC value estimation Bayesian network Bus-off hitting time

Trans-scale surface wrinkling model and scaling relationship analysis of stiff film-compliant substrate structures

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Science China(Technological Sciences) 2022年第11期65卷 2776-2786页

作者： LIU YanWei ZHANG SiYuan long hao WEI YueGuang Department of Mechanics and Enginering SCcience College of EngineeringBIC-ESATPeking UniversiyBeijing 100871China School of Mechanical Engineering University of Shanghai for SCcience and TechnologyShanghai 200093China

The self-assembly of surface-order structures based on the surface wrinkling of stiff film-compliant substrate structures(SFCS)is potentially useful in the fabrication of functional devices,the manufacture of superhydrophobic or self-cleaning surfaces,and so *** to the influence of the intrinsic characteristic length(g),the surface wrinkling behavior of SFCS at the micro scale is different from that at the macro *** this work,based on the strain gradient theory,a trans-scale surface wrinkling model for SFCS is ***,the effectiveness of this model is verified by previous ***,based on the model and dimensional analysis,the effect of g on the surface wrinkling behavior is investigated,and the scaling relationship of surface wrinkling of SFCS at different scales is *** results show that the influence of g cannot be neglected when the film thickness decreases to the one comparable to *** the micro scale,g will lead to the increase of the critical wrinkling wavelength and *** addition,the scaling relationship of surface wrinkling at the micro scale will not follow the traditional *** study explains the underlying mechanism of the dissimilarity of surface wrinkling behaviors of SFCS at different scales and lays a theoretical foundation for the precise control of surface-order structures.

关键词： stiff film-compliant substrate structures surface wrinkling trans-scale model dimensional analysis scaling relationship

Fabrication of corrosion inhibiting microcapsules functional coating and their high-efficiency corrosion resistance

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Rare Metals 2024年第2期43卷 842-848页

作者： hao-Ran Yun Lu Lu Xue-long hao Xing-Xiang Zhang School of Material Science and Engineering Tiangong UniversityTianjin300387China National Center of Analysis and Testing for Nonferrous Metals and Electronic Materials General Research Institute for Nonferrous MetalsBeijing100088China Guobiao(Beijing)Testing&Certification Co. Ltd.Beijing101407China

Benzotriazole(BTA)was loaded into calcium carbonate microsphere shell by self-assembly method and a new type of high-efficiency corrosion inhibiting microcapsules(CIMs)were fabricated,which were added and dispersed into epoxy resin coating to obtain a new corrosion resistance functional *** corrosion inhibition effect of benzotriazole on aluminum alloy matrix was verified by polarization curve *** effectiveness of the CIMs and their loading capacity on inhibitor were evaluated by scanning electron microscope,laser confocal Raman spectroscopy together with thermogravimetric analysis.

关键词： corrosion coating resistance

VLBI observations with the Kunming 40-meter radio telescope

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Research in Astronomy and Astrophysics 2010年第8期10卷 805-814页

作者： long-Fei hao Min Wang Jun Yang National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Joint Institute for VLBI in Europe Postbus 2 7990 AA Dwingeloo The Netherlands

The Kunming 40-meter radio telescope is situated in the yard of the Yunnan Astronomical Observatory （longitude： 102.8° East, Latitude： 25.0° North） and saw its first light in 2006 May. The Kunming station successfully joined the VLBI tracking of China＇s first lunar probe ＂Chang＇E-1＂ together with the other Chinese telescopes： the Beijing Miyun 50-meter radio telescope, Urumqi Nanshan 25-meter radio telescope, and Shanghai Sheshan 25-meter radio telescope, and received the downlinked scientific data together with the Miyun station from October of 2007 to March of 2009. We give an introduction to the new Chinese VLBI facility and investigate its potential applications. Due to its location, the Kunming station can significantly improve the u - v coverage of the European VLBI Network （EVN）, in particular, in long baseline observations. We also report the results of the first EVN fringe-test experiment of N09SX1 with the Kunming station. The first fringes in the European telescopes were successfully detected at 2.3 GHz with the ftp-transferred data on 2009 June 17. From scheduling the observations to performing the post correlations, the Kunming station shows its good compatibility to work with the EVN. The imaging result of the extended source 1156＋295 further demonstrates that the Kunming station greatly enhances the EVN performance.

关键词： radio telescopes -- instrumentation interferometers VLBI

Microstructure induced galvanic corrosion evolution of SAC305 solder alloys in simulated marine atmosphere

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Journal of Materials Science & Technology 2020年第16期47卷 40-53页

作者： Mingna Wang Chuang Qiao Xiaolin Jiang long hao Xiahe Liu Department of Physics Hebei Normal University of Science&TechnologyQinhuangdao 066004China School of Metallurgy Northeastern UniversityShenyang 110819China Environmental Corrosion Centre of Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Material Science and Engineering University of Science and Technology of ChinaHefei 230026China

Motivated by the increasing use of Sn-3.0 Ag-0.5 Cu(SAC305)solder in electronics worked in marine atmospheric environment and the uneven distribution of Ag3Sn and Cu6Sn5 intermetallic compounds(IMCs)inβ-Sn matrix,comb-like electrodes have been designed for in-situ EIS measurements to study the microstructure induced galvanic corrosion evolution of SAC305 solder in simulated marine atmosphere with high-temperature and *** indicate that in-situ EIS measurement by comb-like electrodes is an effective method for corrosion evolution behavior study of SAC305 ***,the galvanic effect between Ag3Sn IMCs andβ-Sn matrix can aggravate the corrosion of both as-received and furnace-cooled SAC305 solder as the exposure time proceeds in spite of the presence of corrosion product *** corrosion can be preferentially found on furnace-cooled SAC305 with larger Ag3Sn grain ***,the generated inner stress during phases transformation process with Sn3O(OH)2Cl2 as an intermediate and the possible hydrogen evolution at local acidified sites are supposed to be responsible for the loose,porous,cracked,and non-adherent corrosion product *** findings clearly demonstrate the corrosion acceleration behavior and mechanism of SAC305 solder,and provide potential guidelines on maintenance of microelectronic devices for safe operation and longer in-service duration.

关键词： SAC305 solder Marine atmosphere Galvanic corrosion In-situ EIS Comb-like electrode

Intrinsic physical relationships between rotor modal shapes and instantaneous vibrational energy flow transmission characteristics:Theoretical and numerical analysis and application

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Chinese Journal of Aeronautics 2020年第12期33卷 3288-3305页

作者： Yingqun MA Qingjun Zhao Wei Zhao Binbin LIU long hao Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Light-duty Gas-turbine Chinese Academy of SciencesBeijing 100190China

The modal vibration of the rotor is the main cause of excessive vibration of the aeroengine overall *** attenuate the vibration of the rotor under different modal shapes from the perspective of energy control,the intrinsic physical relationships between rotor modal shapes and instantaneous vibrational energy flow transmission characteristics is derived from the general equation of motion base on the structural intensity method.A dual-rotor-support-casing coupling model subjected to the rotor unbalanced forces is established by the finite element method in this *** transmission,conversion and balance relationships of the vibrational energy flow for the rotors in the first-order bending modal shape,the conical whirling modal shape and the translational modal shape are analyzed,*** results show that the vibrational energy flow transmitted to the structure can be converted into the strain energy,the kinetic energy and the energy dissipated by the damping of the *** vibrational energy flow transmission characteristics of rotors with different modal shapes are quite *** for the first-order bending modal shape,the vibrational energy flow and the strain energy are transmitted and converted to each other in the middle part of the rotor shaft,resulting in large deformation at this *** attenuate this harmful vibration,the influences of grooving on the shaft on the first-order bending vibration are studied from the perspective of transmission control of vibrational energy *** study can provide theoretical references and guidance for the vibration attenuation of the rotors in different modal shapes from a more essential perspective.

关键词： Energy balance relationship Instantaneous vibrational energy flow Rotor modal shapes Rotor vibration attenuation Structural intensity method Transmission characteristics

Non-adiabatic holonomic quantum operations in continuous variable systems

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 12-19页

作者： hao-long Zhang Yi-hao Kang Fan Wu Zhen-Biao Yang Shi-Biao Zheng Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information EngineeringFuzhou UniversityFuzhou 350116China

Quantum operations by utilizing the underlying geometric phases produced in physical systems are favoured due to their potential *** a system in a non-degenerate eigenstate undergoes an adiabatically cyclic evolution dominated by its Hamiltonian,it will get a geometric phase,referred to as the Berry *** a non-adiabatically cyclic evolution produces an Aharonov-Anandan geometric *** two types of Abelian geometric phases are extended to the non-Abelian cases,where the phase factors become matrix-valued and the transformations associated with different loops are *** and non-Abelian(holonomic)operations are prevalent in discrete variable systems,whose limited(say,two)energy levels,form the *** their developments in continuous systems have also been investigated,mainly due to that,bosonic modes(in,such as,cat states)with large Hilbert spaces,provide potential advantages in fault-tolerant quantum *** we propose a feasible scheme to realize non-adiabatic holonomic quantum logic operations in continuous variable systems with cat *** construct arbitrary single-qubit(two-qubit)gates with the combination of single-and two-photon drivings applied to a Kerr Parametric Oscillator(KPO)(the coupled KPOs).Our scheme relaxes the requirements of the previously proposed quantum geometric operation strategies in continuous variable systems,providing an effective way for quantum control.

关键词： cat qubit continuous variable systems non-Abelian

Multi-Bernoulli Filter for Tracking Multiple Targets Using Sensor Array

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China Ocean Engineering 2020年第2期34卷 245-256页

作者： ZHANG Guang-pu ZHENG Ce QIU long-hao SUN Si-bo Acoustic Science and Technology Laboratory Harbin Engineering UniversityHarbin 150001China College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China Qindao Haina Underwater Information Technology Co. Ltd.Qindao 266500China

This paper presents a multi-Bernoulli filter for tracking the direction of arrival(DOAs)of time-varying number of targets using sensor *** method operates directly on the measurements of sensor array and does not require any ***,more information is reserved and compared with the after-detection measurements using a finite set of detected *** can significantly improve the tracking performance,especially in low signal-to-noise ***,it inherits the advantages of the multi-Bernoulli approximation which models each of the targets *** allows more accurate multi-target state estimation,especially when targets *** proposed filter does not need clustering step and simulation results showcase the improved performance of the proposed filter.

关键词： multiple target tracking multi-Bernoulli filter direction of arrival estimation random finite set track-before-detect