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Design of modified model of intelligent assembly digital twins based on optical fiber sensor network

Digital Communications and Networks 2024年第5期10卷 1542-1552页

作者： zhichao Liu Jinhua Yang Juan Wang Lin Yue School of Opto-Electronic Engineering Changchun University of Science and Technology Key Laboratory of Optoelectric Measurement and Optical Information Transmission Technology of Ministry of Education Changchun University of Science and Technology Department of Actuarial Science and Business Analytics Macquarie UniversityNSW

Intelligent assembly of large-scale,complex structures using an intelligent manufacturing platform represents the future development direction for industrial *** large-scale structural assembly processes,several bottleneck problems occur in the existing auxiliary assembly ***,the traditional LiDARbased assembly technology is often limited by the openness of the manufacturing environment,in which there are blind spots,and continuous online assembly adjustment thus cannot be ***,for assembly of large structures,a single-station LiDAR system cannot achieve complete coverage,which means that a multi-station combination method must be used to acquire the complete three-dimensional data;many more data errors are caused by the transfer between stations than by the measurement accuracy of a single station,which means that the overall system's measurement and adjustment errors are increased ***,because of the large numbers of structural components contained in a large assembly,the accumulated errors may lead to assembly interference,but the LiDAR-assisted assembly process does not have a feedback perception capability,and thus assembly component loss can easily be caused when assembly interference ***,this paper proposes to combine an optical fiber sensor network with digital twin technology,which will allow the test data from the assembly entity state in the real world to be applied to the "twin" model in the virtual world and thus solve the problems with test openness and data *** problem of station and perception feedback is also addressed and represents the main innovation of this *** system uses an optical fiber sensor network as a flexible sensing medium to monitor the strain field distribution within a complex area in real time,and then completes real-time parameter adjustment of the virtual assembly based on the distributed *** areas include areas that are laser-unreachable,areas

关键词： Digital twins Intelligent manufacturing Intelligent assembly Optical fiber sensor network Assembly condition monitoring algorithm

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Modal characteristics analysis for a flexible rotor with non-smooth constraint due to intermittent rub-impact

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Chinese Journal of Aeronautics 2018年第3期31卷 498-513页

作者： Jie HONG Pingchao YU Dayi ZHANG zhichao LIANG School of Energy and Power Engineering Beihang University Collaborative Innovation Center of Advanced Aero-Engine Beihang University

Intermittent rub-impact, during which the contact between rotor and stator is characterized by a ‘‘bouncing＂ or intermittent type of behavior, is one of the most common rubbing forms in rotating machinery. When the intermittent rub-impact occurs, the non-smooth constraint, which is the phenomenon that the system stiffness changes with respect to the state of contact and noncontact, will appear. The paper aims at discovering the possible effects of the non-smooth constraint on the flexible rotor＇s modal characteristics by theoretical and experimental methods. The qualitative description for non-smooth constraint is given for the intermittent rub-impact process, and the dynamic modeling for a rotor system with non-smooth constraint is carried out. Meanwhile, the analysis method is developed by Floquet theory and Hill＇s method to obtain the rotor＇s modal characteristics. The results reveal that the non-smooth constraint produced by the intermittent rubimpact will increase the modal frequencies and critical speeds of the rotor system *** to the time-varying features of the constraint stiffness, the modal frequencies for the intermittent rub-impact rotor present fluctuant changes with the increase of rotation speed, which is different from the general linear rotor system. The non-smooth constraint is possible to lead the rotor＇s instability, and the rotor＇s instable regions can be expanded significantly for the increase of average constraint stiffness, constraint amplitude and contact time ratio. Non-smooth constraint could also expand the resonance speed and resonance sideband of the rotor system, which sometimes results in amplitude jump phenomenon.

关键词： Flexible rotor Intermittent rub-impact Instabifity Modal characteristics Non-smooth constraint

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Infrared radiation characteristics of a hypersonic vehicle under time-varying angles of attack

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Chinese Journal of Aeronautics 2019年第4期32卷 861-874页

作者： Qinglin NIU zhichao YUAN Biao CHEN Shikui DONG School of Energy Science and Engineering Harbin Institute of Technology Key Laboratory of Aerospace Thermophysics of Ministry of Industry and Information Technology Harbin Institute of Technology Key Laboratory of Chemical Laser Dalian Institute of Chemical Physics Chinese Academy of Sciences

Hypersonic vehicles emit strong infrared(IR) radiation signatures that can be treated as a detecting source for object identification and routine diagnosis. This paper is aimed at examining the intrinsic radiation characteristics of a Boost-Glide Vehicle(BGV) under the condition of various Angles of Attack(AOAs). A two-temperature model considering the thermal and chemical nonequilibrium effects is coupled with Navier-Stokes equations solved by the finite volume technique.A gas–solid conjunction heat transfer model is also added into the fluid solver to simulate the surface temperature of the vehicle. The radiative transfer equation is solved with Line of Sight(LOS)algorithm. The computational results for a Hypersonic Technology Vehicle-2(HTV-2) type vehicle show that radiances of the vehicle are strongly dependent on the surface temperature. The presence of AOA results in the significant difference of the surface temperature. Infrared radiation characteristics are also changed in intensity and spectral band due to the AOA. Simulations are performed with two time-varying AOAs. Transient results indicate that the variation of AOA does have a great effect on the infrared radiance and is closely related to observation angle, spectral band, angle size,angular velocity and time history.

关键词： Angle of attack Fluid-thermal interaction HTV-2 Hypersonic vehicle IR radiation Surface temperature

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Segregation behaviors of Sc and unique primary Al3Sc in Al-Sc alloys prepared by molten salt electrolysis

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Journal of Materials Science & Technology 2019年第7期35卷 1422-1431页

作者： Xuan Liu Jilai Xue zhichao Guo Cheng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

This work mainly deals with the segregating behaviors of Sc and the growth of unique primary Al3Sc in AlSc alloys prepared by molten salt electrolysis. The alloys contain 0.23–1.38 wt%Sc where Sc segregation is observed. It is found that a high current density and long electrolysis time are in favor of high Sc content, and so do the high temperature and the addition level of Sc2O3. Sc content at the edge of Al based alloy(average Sc content: 0.75 wt%) can be as high as 1.09 wt%, while it is merely 0.24 wt% at the central area. The cooling rates have a strong impact on the morphology and particle size of primary Al3Sc,but a weak influence on Sc segregation. The cusped cubic and dendritic primary Al3Sc can precipitate in the prepared Al-Sc alloys. In a slightly hypereutectic Al-0.67 wt%Sc alloy, a large and cusped dendrite grows from the edge into the center. The primary and secondary dendritic arms can be as long as 600 and 250 μm, respectively. The Sc segregating behaviors in Al-Sc alloys is due to the mechanism controlled by the limited diffusion rate of Sc in liquid Al. This can involve the establishment of a near spherical discharge interface between liquid Al and the electrolyte. The Sc rich layer near Al-molten salt interface may provide the potential primary nuclei and sufficient Sc atoms for the growth of large dendritic primary Al3Sc.

关键词： Al-Sc alloys Electrolysis Segregation Primary Al3Sc Discharge reaction

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Outlier detection in near-infrared spectroscopic analysis by using Monte Carlo cross-validation

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Science China Chemistry 2008年第8期51卷 751-759页

作者： LIU zhichao CAI WenSheng SHAO XueGuang Research Center for Analytical Sciences College of ChemistryNankai UniversityTianjin 300071China

An outlier detection method is proposed for near-infrared spectral analysis. The underlying philosophy of the method is that,in random test(Monte Carlo) cross-validation,the probability of outliers presenting in good models with smaller prediction residual error sum of squares(PRESS) or in bad models with larger PRESS should be obviously different from normal samples. The method builds a large number of PLS models by using random test cross-validation at first,then the models are sorted by the PRESS,and at last the outliers are recognized according to the accumulative probability of each sample in the sorted models. For validation of the proposed method,four data sets,including three published data sets and a large data set of tobacco lamina,were investigated. The proposed method was proved to be highly efficient and veracious compared with the conventional leave-one-out(LOO) cross validation method.

关键词： near-infrared spectrum partial least squares(PLS) Monte Carlo cross validation Outlier detection

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One-Step Synthesis of Magnetic Zeolite from Zinc Slag and Circulating Fluidized Bed Fly Ash for Degradation of Dye Wastewater

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Journal of Renewable Materials 2020年第4期8卷 405-416页

作者： zhichao Han Yaojun Zhang Panyang He College of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an710055China

In this study,a magnetic P zeolite was directly synthesized by utilization of industrial solid wastes of zinc slag(ZS)and circulating fluidized bed fly ash(CFBFA)via one-step hydrothermal *** effects of different CFBFA/ZS ratios and hydrothermal times on the as-synthesized zeolite were *** X-ray diffraction(XRD)and vibrating sample magnetometer(VSM)results indicated that the magnetic P zeolite possessed well-defined crystals and *** as-prepared zeolite was employed as a Fenton-like solid catalyst for degradation of direct green B dye *** was discovered that the magnetic P zeolite took the advantage of rapid separation and efficient recovery under the external magnets in a solid-liquid *** effects of the solution pH,the catalyst dosage,and the H_(2)O_(2)concentration on the degradation rate of direct green B dye wastewater were studied *** results showed that the highest degradation of 96.3%was obtained and the magnetic P zeolite showed excellent stability after four ***,the magnetic P zeolite derived from industrial solid wastes had a potential application in wastewater treatment.

关键词： Magnetic zeolite solid wastes Fenton-like reaction dye degradation

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Synthesis of a novel functional group-bridged magnetized bentonite adsorbent:Characterization,kinetics,isotherm,thermodynamics and regeneration

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Chinese Journal of Chemical Engineering 2017年第5期25卷 587-594页

作者： zhichao Lou Wei Zhang Xiaodan Hu Haiqian Zhang College of Materials Science and Engineering Nanjing Forestry University College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics State Key Laboratory of Bioelectronics Jiangsu Key Laboratory for Biomaterials and DevicesSchool of Biological Science and Medical EngineeringSoutheast University

A novel magnetic adsorbent was synthesized by magnetizing bentonite by APTES-Fe_3O_4 via a functional groupbridged interaction. The characterization of APTES-Fe_3O_4/bentonite was conducted via transmission electron microscope(TEM), X-ray diffraction(XRD), Fourier transform infrared spectrophotometer(FT-IR), thermal gravimetric analysis(TGA), vibrating sample magnetometer(VSM), zeta potential analysis and Brunner–Emmet–Teller(BET). The APTES-Fe_3O_4/bentonite was assessed as adsorbents for methylene blue(MB) with a high adsorption capacity(91.83 mg·g^(-1)). Factors affecting the adsorption of MB(such as p H, equilibrium time, temperature and initial concentration) were investigated. The adsorption process completely reaches equilibrium after 120 min and the maximum sorption is achieved at p H 8.0. The adsorption trend follows the pseudosecond order kinetics model. The adsorption data gives good fits with Langmuir isotherm model. The parameter factor RLfalls between 0 and 1, indicating the adsorption of MB is favorable. The adsorption process is endothermic with positive ΔH^0 values. The positive values of ΔG^0 confirm the affinity of the adsorbent towards MB, and suggest an increased randomness at the solid–liquid interface during the adsorption process. Regeneration of the saturated adsorbent was easily carried out via gamma-irradiation.

关键词： Adsorption Magnetize Kinetics Isotherm Thermodynamics

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2-Ethyl-9,10-anthraquinone assisted sol–gel synthesis of Pd/γ-Al2O3 nanorods with enhanced catalytic performance in 2-ethyl-9,10-anthraquinone hydrogenation

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Chinese Journal of Chemical Engineering 2019年第8期27卷 1863-1869页

作者： Weiquan Cai Junlin Zhuo Jimin Fang zhichao Yang School of Chemistry and Chemical Engineering Guangzhou University230 Guangzhou University City Outer Ring RoadGuangzhou 510006China School of Chemistry Chemical Engineering and Life SciencesWuhan University of TechnologyWuhan 430070China School of Resources and Environmental Engineering Wuhan University of TechnologyWuhan 430070China

A series of nanorod-like porous Pd/γ-Al2 O3 catalysts with controllable textural properties and enhanced catalytic performance in 2-ethyl-9,10-anthraquinone(eAQ) hydrogenation for H2 O2 preparation were successfully prepared via a facile sol-gel method using aluminum isopropoxide as aluminum precursor and eAQ as structure directing agent,sequential calcination and impregnation process with Na2 PdCl4 *** physicochemical properties of the catalysts obtained with different addition amounts of *** comparatively characterized by XRD,TG-DSC,BET,TEM,CO-TPR,H2-TPR and H2-O2 *** results show that addition of eAQ can not only effectively control the textural properties(surface area,pore volume and average pore size) of the catalysts,but also lower their reduction temperature of active ***,the catalyst obtained with an addition amount of 4 wt% eAQ shows the highest hydrogenation efficiency of 10.28 g·L^-1,which is 37.3% higher than 7.49 g·L^-1 of the catalyst obtained without eAQ.

关键词： Catalyst Hydrogenation Alumina 2-Ethyl-9,10-anthraquinone Structure directing agent H2O2

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Numerical analyses of coupled thermo-mechanical behaviors of cement sheath in geothermal wells

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Underground Space 2023年第1期8卷 80-93页

作者： Hao Wang Jinlin Wang zhichao Zhang Xiaohui Cheng State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China School of Civil Engineering Chongqing UniversityChongqing 400045China Department of Civil Engineering Tsinghua UniversityBeijing 10084China

The stability of cement sheath under high temperature and high pressure is one of the most critical issues for the durability of geother-mal well *** this study,a two-dimensional plane-strain finite element code was developed to investigate the coupled thermo-mechanical behaviors of the casing-cement-formation *** from previous linear elastic analyses,a thermoelasto-plastic con-stitutive model based on the thermodynamic theory was adopted for the cement *** is shown that the finite element simulations using the proposed model provide a more accurate and realistic prediction of stress–strain responses of the cement sheath under high *** results demonstrate that the radial stress concentration and the tensile strain concentration occur at both the cement–casing interface and the cement–formation interface,where the cement sheath is most likely to *** strength and low stiff-ness in the cement sheath and the formation are preferred for the integrity of the *** large thermal cycles and large differences between the internal fluid pressure and the external pressure should be avoided during *** new code is an alternative tool for guiding the geothermal well *** finite element framework described herein is universal for other thermo-mechanical applications,such as energy foundations and energy tunnels.

关键词： Geothermal well Thermal-mechanical coupling Finite element analysis Constitutive model Cement sheath Thermodynamic theory

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Virtual special issue:Supramolecular/macrocyclic chemistry

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Chinese Chemical Letters 2018年第12期29卷 1703-1705页

作者： Xiaoyu Hu zhichao Pei School of Materials Science and Technology Nanjing University of Aeronautics and Astronautics College of Chemistry & Pharmacy Northwest A&F University

Welcome to this virtual special issue, which focuses on supramolecular/macrocyclic Chemistry. The beginnings of supramolecular chemistry can be traced back to 1967 with the identification of crown ethers by Pedersen [1], and being acknowledgement by the 1987 Nobel Prize to Lehn, Cram, and Pedersen for their leading discoveries in the host-guest systems [2]. Since these

关键词： Virtual special issue:Supramolecular/macrocyclic chemistry CB

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