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Digital Twin-based Quality management Method for the Assembly Process of Aerospace Products with the Grey-markov Model and Apriori Algorithm

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 66-86页

作者： Cunbo Zhuang Ziwen Liu Jianhua Liu Hailong ma Sikuan Zhai Ying Wu Laboratory of Digital manufacturing School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing 314000China Shanghai Institute of Spacecraft Equipment Shanghai 200240China

The assembly process of aerospace products such as satellites and rockets has the characteristics of single-or small-batch production,a long development period,high reliability,and frequent *** to predict and avoid quality abnormalities,quickly locate their causes,and improve product assembly quality and efficiency are urgent engineering *** the core technology to realize the integration of virtual and physical space,digital twin(DT)technology can make full use of the low cost,high efficiency,and predictable advantages of digital space to provide a feasible solution to such ***,a quality management method for the assembly process of aerospace products based on DT is *** that traditional quality control methods for the assembly process of aerospace products are mostly post-inspection,the Grey-markov model and T-K control chart are used with a small sample of assembly quality data to predict the value of quality data and the status of an assembly *** Apriori algorithm is applied to mine the strong association rules related to quality data anomalies and uncontrolled assembly systems so as to solve the issue that the causes of abnormal quality are complicated and difficult to *** implementation of the proposed approach is described,taking the collected centroid data of an aerospace product’s cabin,one of the key quality data in the assembly process of aerospace products,as an example.A DT-based quality management system for the assembly process of aerospace products is developed,which can effectively improve the efficiency of quality management for the assembly process of aerospace products and reduce quality abnormalities.

关键词： Quality management Digital twin Assembly process Aerospace product Grey markov model Apriori algorithm

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Numerical Simulation of Charging Performance of Combined Sensible-Latent Heat Storage System with a macro-Encapsulation Method

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Journal of Thermal Science 2023年第6期32卷 2008-2017页

作者： WANG Wei PAN Zhenfei LEI Biao WU Yuting WANG Jingfu ma Chongfang Key Laboratory of Enhanced Heat Transfer and Energy Conservation Ministry of EducationCollege of Energy and Power EngineeringBeijing University of TechnologyBeijing100124China Key Laboratory of Heat Transfer and Energy Conversion Beijing MunicipalityCollege of Energy and Power EngineeringBeijing University of TechnologyBeijing100124China

In recent years,heat storage system combining sensible and latent heat materials has received more and more *** this paper,we proposed the hybrid configuration with a macro-encapsulation,and analyzed its charging performance with different influencing factors by CFD *** the case,the sensible heat storage materials are magnesia brick or HT concrete and the phase change materials(PCMs)are mixed molten ***,we analyzed the heat transfer characteristics of the hybrid configuration in charging ***,we analyzed the effect of heating power on charging *** maximum temperature of the heating surface shall not exceed 500℃as the constraint condition,the heat storage capacity increases at first and then decreases with the heating ***,we compared the charging performance of different solid structure and the hybrid *** magnesia brick or HT concrete,the charging performance of the solid structure is better than that of the hybrid configuration,because the thermal conductivity of the molten salt is significantly lower than that of the two sensible heat storage ***,we compared the charging performance of different molten *** hybrid configuration with lower melting point molten salt has better performance because of more intensity natural ***,we analyzed the charging performance of the hybrid configuration used the composite phase change material(CPCM)with high thermal conductivity and specific *** the result,the charging performance increases by 22.5%compared with the solid *** results indicate that the hybrid configuration with the macro-encapsulation method is a potential form of thermal energy storage,but it needs to be further optimized.

关键词： thermal energy storage hybrid configuration natural convection thermophysical property charging performance

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Influence of uniaxial tensile pre-strain on forming limit curve by using biaxial tensile test

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Chinese Journal of Aeronautics 2020年第8期33卷 2268-2280页

作者： Wennan YUAN Min WAN Xiangdong WU Bolin ma Xu LU Bing YANG Department of Mechanical Engineering and Automation Beijing University of Aeronautics and AstronauticsBeijing 100083China Research Institute of Baosteel Shanghai 201900China

This paper focused on the effect of pre-strain on forming limit curves(FLC)of 5754-O aluminum alloy sheet through utilizing biaxial tensile *** on Swift model and Yld2000-2 d yield criterion,the dimensions of cruciform specimen was optimized through applying finite element method for increasing the strain at specimen *** that,with the recommended specimen size,the cruciform specimen was tested under various stroke ratios to experimentally characterize the limit strains under different pre-strain ***,the biaxial tensile tests were simulated by Abaqus to obtain the limit strains and validate the material *** can be observed in both experiments and simulations that the pre-strained uniaxial tension followed by plane tension or equi-biaxial tension can improve the formability of sheet ***,the strain path change affects the trend of first derivative of strain rate difference between neighboring points with respect to *** early increase occurred and then fell back to the stable value,the steady evolution continued until to a new increase reaching the critical *** M–K prediction approach was simulated to verify the influence of pre-strain on *** can be found that the early increase peaks of the major strain incremental ratio rose with the amplitude of ***,the phenomenon of pseudolocalization caused by the strain path change was explained through evolution of stress state inside the groove.

关键词： Aluminum alloy sheet Biaxial tensile tests Formability M–K model Yld2000-2d

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Response of soil respiration to environmental and photosynthetic factors in different subalpine forest-cover types in a loess alpine hilly region

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Journal of Forestry Research 2022年第2期33卷 653-665页

作者： Yuanhang Li Sha Lin Qi Chen Xinyao ma Shuaijun Wang Kangning He School of Soil and Water Conservation Key Laboratory of State Forestry Administration On Soil and Water ConservationBeijing Forestry UniversityBeijing 100083People’s Republic of China Beijing Engineering Research Center of Soil and Water Conservation Beijing Forestry UniversityBeijing 100083People’s Republic of China Engineering Research Center of Forestry Ecological Engineering Ministry of EducationBeijing Forestry UniversityBeijing 100083People’s Republic of China North China Power Engineering Co. Ltd.of China Power Engineering Consulting GroupChangchun 130021People’s Republic of China Power China Huadong Engineering Corporation Limited Hangzhou 311122People’s Republic of China

Soil respiration(Rs)is important for transport-ing or fixing carbon dioxide from the atmosphere,and even diminutive variations can profoundly influence the carbon ***,the R_(s) dynamics in a loess alpine hilly region with representative sensitivity to climate change and fragile ecology remains poorly *** study investigated the correlation and degree of control between R_(s) and its photosynthetic and environmental factors in five subalpine forest cover *** examined the correlations between R_(s) and variables temperature(T_(10)) and soil moisture content at 10 cm depth(W_(10)),net photosynthetic rate(P_(n))and soil properties to establish multiple models,and the variables were measured for diurnal and monthly vari-ations from September 2018 to August *** results showed that soil physical factors are not the main drivers of R_(s) dynamics at the diel scale;however,the trend in the monthly variation in R_(s) was consistent with that of T_(10)and P_(n).Further,R_(s) was significantly affected by pH,providing further evidence that coniferous forest leaves contribute to soil acidification,thus reducing R_(s).Significant exponential and linear correlations were established between R_(s) and T_(10)and W_(10),respectively,and R_(s) was positively correlated with P_(n).Accordingly,we established a two-factor model and a three-factor model,and the correlation coefficients(R_(2))was improved to different degrees compared with models based only on T_(10) and W_(10).Moreover,temperature sensitivity(Q_(10))was the highest in the secondary forest and lowest in the Larix principis-rupprechtii *** findings suggest that the control of R_(s) by the environment(moisture and tempera-ture)and photosynthesis,which are interactive or comple-mentary effects,may influence spatial and temporal homeo-stasis in the region and showed that the models appropriately described the dynamic variation in R_(s) and the carbon cycle in different forest *** add

关键词： Loess alpine hilly region Soil respiration Environmental factor Photosynthesis factor Q_(10) Two-factor model Three-factor model

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Au23（CR）14 nanocluster restores fibril Aβ's unfolded state with abolished cytotoxicity and dissolves endogenous Aβplaques

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National Science Review 2020年第4期7卷 763-774页

作者： Wenkang Zhang Guanbin Gao Zhongjie ma Zhuoying Luo Meng He Taolei Sun State Key Laboratory of Advanced Technology for materials Synthesis and Processing Wuhan University of Technology School of Chemistry Chemical Engineering and Life Science Wuhan University of Technology

The misfolding of amyloid-β（Aβ） peptides from the natural unfolded state to β-sheet structure is a critical step, leading to abnormal fibrillation and formation of endogenous Aβ plaques in Alzheimer's disease（AD）. Previous studies have reported inhibition of Aβ fibrillation or disassembly of exogenous Aβ fibrils in vitro. However, soluble Aβ oligomers have been reported with increased cytotoxicity; this might partly explain why current clinical trials targeting disassembly of Aβ fibrils by anti-Aβ antibodies have failed so *** we show that Au23（CR）14(a new Au nanocluster modified by Cys-Arg（CR） dipeptide) is able to completely dissolve exogenous mature Aβ fibrils into monomers and restore the natural unfolded state of Aβ peptides from misfolded β-sheets. Furthermore, the cytotoxicity of Aβ40fibrils when dissolved by Au23（CR）14is fully abolished. More importantly, Au23（CR）14is able to completely dissolve endogenous Aβ plaques in brain slices from transgenic AD model mice. In addition, Au23（CR）14has good biocompatibility and infiltration ability across the blood–brain barrier. Taken together, this work presents a promising therapeutics candidate for AD treatment, and manifests the potential of nanotechnological approaches in the development of nanomedicines.

关键词： gold nanoclusters Alzheimer’s disease restores fibril Aβ’s unfolded state abolished cytotoxicity dissolves endogenous Aβ plaques

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Seismic effectiveness evaluation and optimized design of tie up method for securing museum collections

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 741-763页

作者： Wang Meng Yan Yi Yang Weiguo Liu Pei Ge Jiaqi ma Botao School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China Beijing’s Key Laboratory of Structural Wind Engineering and Urban Wind Environment Beijing 100044China Beijing General Municipal Engineering Design&Research Institute Co. LtdBeijing 100082China China Aviation Planning and Design Institute(Group)Co.Ltd. Beijing 100120China

To quantify the seismic effectiveness of the most commonly used fishing line tie up method for securing museum collections and optimize fixed strategies for exhibitions,shaking table tests of the seismic systems used for typical museum collection replicas have been carried *** influence of body shape and fixed measure parameters on the seismic responses of replicas and the interaction behavior between replicas and fixed measures have been *** on the results,seismic effectiveness evaluation indexes of the tie up method are *** suggestions for fixed strategies are given,which provide a basis for the exhibition of delicate museum collections considering the principle of minimizing seismic responses and *** analysis results show that a larger ratio of height of mass center to bottom diameter led to more intense rocking *** the initial pretension of fishing lines was conducive to reducing the seismic responses and stress variation of the *** comprehensive consideration of the interaction forces and effective securement,it is recommended to apply 20%of breaking stress as the initial *** specific museum collections that cannot be effectively protected by the independent tie up method,an optimized strategy of a combination of fishing lines and fasteners is recommended.

关键词： tie up method museum collections shaking table test seismic effectiveness optimized design

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Importance of metal location in M-H zeolite for synergistically catalyzing dimethyl ether carbonylation

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Chinese Journal of Chemical Engineering 2022年第1期35卷 350-357页

作者： Shiyue Li Shouying Huang Kai Cai Ying Li Jing Lv Xinbin ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China

Mordenite(MOR)has shown great potential to catalyze dimethyl ether(DME)carbonylation to methyl acetate(ma)in *** synergy between metal species and Brønsted acid sites accelerates DME *** we designed and prepared two catalysts with different Ag locations by seed-directed growth method and two-step impregnation method(named as Ag@HMOR and Ag/HMOR-out,respectively),to explain the effect of Ag location on catalytic *** results of TEM,XPS,CO-IR and UV–Vis showed that Ag species mainly presented as Ag^(0) species over both Ag@HMOR and Ag/***,Ag^(0) species mainly located in the micropores of Ag@HMOR,while as for Ag/HMOR-out,Ag^(0) mainly existed on external *** comparing the performance of the catalysts with different Ag positions,we confirmed that the Ag^(0) species encapsulated in the channels of HMOR promoted the DME carbonylation,which revealed the importance of spatial adjacency on the acid-metal catalysts.

关键词： Dimethyl ether Carbonylation Silver modification Metal location

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Eu^(3+)ions grafted polyacrylonitrile nanofibers possessing enhanced fluorescence performance by introducing benzoic acid as assistant ligand

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Journal of Rare Earths 2022年第3期40卷 421-427,I0003页

作者： Ping Wu Qianli ma Wensheng Yu Jinxian Wang Guixia Liu Xiangting Dong Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province Changchun University of Science and TechnologyChangchun 130022China

Eu^(3+) ions were grafted onto the surface of electrospun polyacrylonitrile(PAN)nanofibers through coordination effect between C≡N groups on PAN nanofibers and Eu^(3+) ions,and benzoic acid(BA)was introduced as an assistant *** impacts of concentrations of Eu^(3+) ions and BA,and reaction time on the properties of final products were *** results reveal that Eu^(3+) ions can be successfully grafted onto PAN nanofibers,but the fluorescence intensity of the obtained PAN@Eu^(3+) nanofibers is very *** BA is introduced as the assistant ligand,the fluorescence intensity of the obtained PAN@(Eu^(3+)/BA)nanofibers is greatly stronger than that of PAN@Eu^(3+)nanofibers,and meanwhile,concentration quenching effect of Eu^(3+) ions can be effectively ***,the superior structure of PAN@(Eu^(3+)/BA)nanofibers not only brings the effective utilization of precious elemental europium,but also guarantees high mechanical strength.

关键词： Electrospinning Polyacrylonitrile Nanofibers Fluorescence Rare earths

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Development of data-driven thermal sensation prediction model using quality-controlled databases

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Building Simulation 2022年第12期15卷 2111-2125页

作者： Xiang Zhou Ling Xu Jingsi Zhang Lie ma Mingzheng Zhang maohui Luo School of Mechanical Engineering Tongji UniversityShanghai200092China Guangdong Midea Air-Conditioning Equipment Co. LTDGuangdong 528311China

Predicting the thermal sensations of building occupants is challenging,but useful for indoor environment *** this study,a data-driven thermal sensation prediction model was developed using three quality-controlled thermal comfort *** machine-learning algorithms were compared in terms of prediction accuracy and *** model was further improved by adding categorical inputs,and building submodels and general models for different contexts.A comprehensive data-driven thermal sensation prediction model was *** results indicate that the multilayer perceptron(MLP)algorithm achieves higher prediction accuracy and more rational results than the other four algorithms in this specific *** AC and NV scenarios,climate zones,and cooling and heating seasons can improve model *** submodels for specific scenarios can result in better thermal sensation vote(TSV)predictions than using general models with or without *** 11 submodels corresponding to 11 scenarios,and three general models without labels,the final TSV prediction model achieved higher prediction accuracy,with 64.7%–90.7%fewer prediction errors(reducing SSE by 3.2–4.9)than the predicted mean vote(PMV).Possible applications of the new model are *** findings of this study can help in development of simple,accurate,and rational thermal sensation prediction tools.

关键词： thermal comfort machine learning adaptive thermal comfort multilayer perceptron

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Spatial distribution of supra-permafrost groundwater in the Qinghai-Tibet Engineering Corridor using inversion models

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Advances in Climate Change Research 2024年第1期15卷 31-41页

作者： Yu GAO Ming-Tang CHAI Wei ma Yu-Tao GAO State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China School of Civil and Hydraulic Engineering Ningxia UniversityYinchuan 750021China

Supra-permafrost groundwater(SPG)is a key factor that causes damage to highways and railways in the Qinghai-Tibet Engineering Corridor(QTEC).It is difficult to monitor SPG in the field due to their complex formation mechanisms and movement *** single-site field monitoring studies limit the spatial and temporal precision of SPG spatial *** determine the moisture content of shallow soils and the SPG distribution along the QTEC,this work employed the temperature vegetation dryness index and remote sensing models for groundwater table distribution *** accuracies of the models were validated using mea-surements obtained from different sites in the *** the permafrost zones of the QTEC,72%,22%and 6%of the SPG were located at depths of 0.5-1,1 m,***,79.4%of the area along the Qinghai-Tibet Highway(QTH)(Xidatan-Tanggula)section contained *** these sections with SPG,37.9%have an SPG table at depths of 0.5-0.8 *** study preliminarily explored the SPG distribution in the QTEC with a 30 m *** findings can help improve the spatial scale of SPG research,provide a basis for the analysis of the hydrothermal mechanisms,and serve as a guide in the assessment of operational risks and road structure designs.

关键词： Dryness index Landsat Soil moisture Groundwater level Qinghai-Tibet Engineering Corridor

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