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Effect of process parameters on steel tube roundness in straightening process

Journal of Iron and Steel Research International 2020年第11期27卷 1270-1283页

作者： li-dong ma Yu-kang Du Zhi-juan Meng li-feng ma Zi-jian liu Pei-yu liu Coordinative Innovation Center of Taiyuan Heavy machinery Equipment Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina School of materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina School of Applied Science Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina

The inclined six-roll tube straightener is an important equipment for the finishing *** can not only straighten the steel pipe,but also finish the ovality of the cross *** the actual straightening process,the cross section of the tube is prone to deform,that is,the round ness is not *** flatteni ng displacement is an import a nt parameter to control cross-section forming of *** to the established mechanical model,the analytical calculation equations of the flattening force and the flattening displacement were derived using the energy *** on the finite element simulation data,the ratios of the finite element results of the什attening force to the analytical ones were *** correlation coefficient after fitting is greater than 99%,and the fitting effect is *** flattening experiment was carried out on tubes of different materials and different specifications,and the setting method of the optimal flattening displacement during straightening process was *** the actual straightening process,using this flattening displacement,the ovality of straightened steel tube is less than 0.3%.Therefore,the proposed method can provide a reference for the flattening displacement in the actual straightening process.

关键词： Straightening Tube Energy method Flattening force Flattening displacement Finite element method

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Comparison of corneal curvature parameters obtained from two different instruments—Pentacam and VX120

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International Journal of Ophthalmology(English edition) 2019年第8期12卷 1311-1316页

作者： Qing-Wei Zhang Chang-Bin Zhai dong-li ma Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Key Laboratory of Ophthalmology and Visual ScienceBeijing Tongren HospitalCapital Medical UniversityBeijing 100730China

AIM: To explore whether the same corneal curvature parameters and anterior chamber depth measured by Pentacam and VX120 have a good consistency and can replace each other. METHODS: This study enrolled 140 eyes of 70 patients ranging in age from 19 to 53 y. All eyes underwent a comprehensive ophthalmologic examination including an anterior segment analysis with the VX120 system(Visionix-Luneau Technologies, Chartres, France) and Pentacam(Oculus Optikgerate GmbH) respectively. The comparison on corneal curvature parameters was done between Pentacam and VX120 using clustered signed rank test;the interclass correlation coefficients(ICC) with 95% confidence intervals(CI) was calculated for each parameter between Pentacam and VX120;the BlandAltman plot of each parameter was supplemented. RESULTS: The anterior corneal curvature measured by VX120 was Ks: 44.00±1.78 D, KsAt: 89.45±22.18, Kf: 42.84±1.58 D, KfAt: 93.91±79.34;which measured by Pentacam was Ks: 43.80±1.82 D, KsAt: 91.17±21.40, Kf: 42.61±1.64 D, KfAt: 91.16±78.69. There was statistical difference between Pentacam and VX120 for anterior corneal curvature parameter(Pman plots indicated oflow consistency of corneal surface curvature parameters measured by Pentacam and VX120. CONCLUSION: The corneal cu

关键词： corneal curvature anterior chamber depth Pentacam VX120 interclass correlation coefficients

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PEG-grafted PVA Membrane and Its Blood Compatibility

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Chemical Research in Chinese Universities 2011年第6期27卷 1078-1082页

作者： JIN Gu YAO Qi-zhi dong li-quan ma Feng Department of Chemistry University of Science and Technology of China Hefei 230026 P. R. China

Preparation and blood compatibility of different shape polyvinyl alcohol（PVA） membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene（PTFE） capillary as supporter] PVA membranes were prepared; then, methoxy polyethylene glycol（mPEG） was grafted onto the surface of the PVA membranes. The effects of the shape, structure and properties of the membrane surface on blood compatibility were studied in detail. The experiment results show that mPEG modified PVA membranes, especially mPEG modified tubular membrane, could availably repel the adhesion of the platelets. In addition, the anticoagulant mechanism of mPEG with a steric repulsion effectiveness was confirmed further via different grafting methods.

关键词： Polyvinyl alcohol(PVA) Polyethylene glycol(PEG) Membrane Platelet Adhesion

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Fast source mask co-optimization method for high-NA EUV lithography

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Opto-Electronic Advances 2024年第4期7卷 44-54页

作者： Ziqi li lisong dong Xu ma Yayi Wei EDA Center Institute of Microelectronics of Chinese Academy of SciencesBeijing 100029China Key Laboratory of Photoelectronic Imaging Technology and System of Ministry of Education of China School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China Guangdong Greater Bay Area Applied Research Institute of Integrated Circuit and Systems Guangzhou 510700China

Extreme ultraviolet(EUV)lithography with high numerical aperture(NA)is a future technology to manufacture the integrated circuit in sub-nanometer ***,source mask co-optimization(SMO)is an extensively used approach for advanced lithography process beyond 28 nm technology *** work proposes a novel SMO method to improve the image fidelity of high-NA EUV lithography system.A fast high-NA EUV lithography imaging model is established first,which includes the effects of mask three-dimensional structure and anamorphic ***,this paper develops an efficient SMO method that combines the gradient-based mask optimization algorithm and the compressivesensing-based source optimization algorithm.A mask rule check(MRC)process is further proposed to simplify the optimized mask *** illustrate that the proposed SMO method can significantly reduce the lithography patterning error,and maintain high computational efficiency.

关键词： computational lithography high-NA EUV lithography source-mask co-optimization lithography imaging model

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Influence of Hot Press Forming Techniques on Properties of Vehicle High Strength Steels

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Journal of Iron and Steel Research International 2011年第5期18卷 59-63页

作者： CHANG Ying MENG Zhao-huan YING liang li Xiao-dong ma Ning HU Ping School of Automotive Engineering State Key Laboratory of Structural Analysis for Industrial EquipmentDalian University of TechnologyDalian 116024LiaoningChina

Based on the combination of materials science and mechanical engineering,hot press forming process of the vehicle high strength steels was analyzed. The hot forming process included：heating alloys rapidly to austenite microstructures,stamping and cooling timely,maintaining pressure and quenching. The results showed that most of austenite microstructure was changed into uniform martensite by the hot press forming while the samples were heated at 900 ℃ and quenched. The optimal tensile strength and yield strength were up to 1530 MPa and 1000 MPa,respectively,and the shape deformation reached about 23%. And springback defect did not happen in the samples.

关键词： high strength steel lightweight hot forming martensite

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Copper slag assisted coke reduction of phosphogypsum for sulphur dioxide preparation

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Chinese Journal of Chemical Engineering 2024年第1期65卷 43-53页

作者： dong ma Qinhui Wang State Key Laboratory of Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou 310027China

The reduction of phosphogypsum(PG)to lime slag and SO_(2)using coke can effectively alleviate the environmental problems caused by ***,the PG decomposition temperature remains high and the product yield remains *** adding additives,the decomposition temperature can be further reduced and PG decomposition rate and product yield can be ***,the use of current additives such as Fe_(2)O_(3)and SiO_(2)brings the problem of increasing economic ***,it is proposed to use solid waste copper slag(CS)as a new additive to reduce PG to prepare SO2,which can reduce the cost and meet the environmental benefits at the same *** effects of proportion,temperature and thermostatic time on PG decomposition are investigated by experimental and kinetic analysis combined with FactSage thermodynamic calculations to optimize the roasting ***,the reaction mechanism is *** is found that adding CS to the coke and PG system can increase the rate of PG decomposition and SO_(2)yield while lowering the PG decomposition *** example,when the CS/PG mass ratio increases from 0 to 1,PG decomposition rate increases from 83.38%to 99.35%,SO_(2)yield increases from 78.62%to 96.81%,and PG decomposition temperature decreases from 992.4℃to 949.6℃.The optimal reaction parameters are CS/PG mass ratio of 1,Coke/PG mass ratio of 0.06 at 1100℃for 20 min with 99.35%PG decomposition rate and 96.81%SO_(2) *** process proceeds according to the following reactions:2CaSO_(4)+ 0.7C + 0.8Fe_(2)SiO_(4)→0.8Ca_(2)SiO_(4)+ 0.2Ca_(2)Fe_(2)O_(5)+ 0.4Fe_(3)O_(4)+2SO_(2)+ 0.7CO_(2)Finally,a process for decomposing PG with coke and CS is proposed.

关键词： Phosphogypsum Sulfur dioxide Copper slag Fluidized-bed Reduction Waste treatment

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Finite-time Prescribed Performance Time-Varying Formation Control for Second-Order Multi-Agent Systems With Non-Strict Feedback Based on a Neural Network Observer

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 1039-1050页

作者： Chi ma Dianbiao dong the School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China

This paper studies the problem of time-varying formation control with finite-time prescribed performance for nonstrict feedback second-order multi-agent systems with unmeasured states and unknown *** eliminate nonlinearities,neural networks are applied to approximate the inherent dynamics of the *** addition,due to the limitations of the actual working conditions,each follower agent can only obtain the locally measurable partial state information of the leader *** address this problem,a neural network state observer based on the leader state information is ***,a finite-time prescribed performance adaptive output feedback control strategy is proposed by restricting the sliding mode surface to a prescribed region,which ensures that the closed-loop system has practical finite-time stability and that formation errors of the multi-agent systems converge to the prescribed performance bound in finite ***,a numerical simulation is provided to demonstrate the practicality and effectiveness of the developed algorithm.

关键词： Finite-time control multi-agent systems neural network prescribed performance control time-varying formation control

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Multiscale microstructural consideration of enhanced shear strength in TiAl intermetallic/K4169 alloy composite joints prepared by vacuum brazing with(Ti,Zr)-Ni-based amorphous filler metal

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Journal of materials Science & Technology 2024年第5期172卷 51-70页

作者： liangliang Zhang Honggang dong Peng li Baosheng Wu Yueting ma libing Huang Chao li Jiachen li School of materials Science and Engineering Dalian University of TechnologyDalian 116024China

TiAl intermetallic could be used to replace Ni-based alloy in assemblies to generate excellent specific strength.A(Ti,Zr)-Ni-based amorphous filler metal Ti_(21.25)Zr_(25)Ni_(25)Cu_(18.75)(at.%)was designed using a cluster-plus-glue-atom model to successfully vacuum braze K4169 and TiAl bimetallic *** various brazing temperatures and holding time,the quantitative relationships between lattice distortion,grain boundary,dislocation density,and hardness,elastic modulus,shear strength of the joints were ***,the fracture mechanism of the joints was *** brazed seam mainly consisted of solid diffusion reaction layers(ZonesⅠandⅢ)and filler metal residue zone(ZoneⅡ).When the brazing temperature increased to 1030℃,grain refinement occurred in the brazed ***Ⅰwas primarily composed of(Ni)ss[0-11]+TiNi[011]/(Cr,Fe,Ni)ss[0-11]/(Ti,Zr)Ni[0-1-1]+(Cr,Fe,Ni)ss[0-11].The(Ti,Zr)(Ni,Cu)[001]and(Ti,Zr)(Ni,Cu)[101]intermetallic compound-based solid solutions were formed in ZoneⅡ.And the lattice distortion of(Ti,Zr)(Ni,Cu)[101]and(Ti,Zr)(Ni,Cu)[001]was 32.05%and 14.82%,*** a result,the proportion of low angle grain boundaries(LAGBs)and deformed grains in ZoneⅡrose to 38.6%and 38.7%.In ZonesⅠandⅢ,the proportion of LAGBs reduced to 8%and 3.4%,*** the holding time increased,the long-range diffusion of Al in ZoneⅡcaused the(Ti,Zr)(Ni,Cu)[001]with cubic structure to transform into(Ti,Zr)(Ni,Cu,Al)[00-1]with hexagonal crystal system structure,where the lattice distortion was 4.42%and 10.49%for a and *** 1030℃/10 min,the average geometrically nec-essary dislocation densities(GNDs)in ZonesⅠ,ⅡandⅢwere 9.87×10^(14)m^(-2),8.55×10^(14)m^(-2)and 11.4×10^(14)m^(-2),***,the shear strength of joints reached 322 MPa due to the lattice distortion,dislocation strengthening and fine grain ***,the plastic and brittle hard phases were generated in ZoneⅡand displayed a mechanical interlocking structure tha

关键词： K4169/Ti_(21.25)Zr_(25)Ni_(25)Cu_(18.75)/TiAl composite joints Intermetallic compound-based solid solution Lattice distortion Elastic modulus

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Effect of Mn content on microstructure and properties of AlCrCuFeMnx high-entropy alloy

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China Foundry 2024年第2期21卷 147-158页

作者： Ning Wang Kai ma Qiu-da li Yu-dong Yuan Yan-chun Zhao li Feng School of materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Advanced Processing and Reuse of Nonferrous Metals Lanzhou 730050China CNNC Nuclear Power Operation and management Co. Ltd.Haiyan 314300ZhejiangChina

AlCrCuFeMnx(x=0,0.5,1,1.5,and 2)high-entropy alloys were prepared using the vacuum arc melting *** microstructure and mechanical properties of AlCrCuFeMnxwere analyzed and tested by XRD,SEM,TEM,nanoindentation,and electronic universal *** results indicate that the AlCrCuFeMnxhigh-entropy alloy exhibits a dendritic structure,consisting of dendrites with a BCC structure,interdendrite regions with an FCC structure,and precipitates with an ordered BCC structure that form within the ***(Mn)has a strong affinity for dendritic,interdendritic,and precipitate structures,allowing it to easily enter these *** an increase in Mn content,the size of the precipitated nanoparticles in the dendritic region initially increases and then ***,the area fraction initially decreases and then ***,the alloy’s strength and wear resistance decrease,while its plasticity *** Al Cr Cu Fe Mn1.5alloy boasts excellent mechanical properties,including a hardness of 360 HV and a wear rate of 2.4×10^(-5)mm^(3)·N^(-1)·mm^(-1).It also exhibits impressive yield strength,compressive strength,and deformation rates of 960 MPa,1,700 MPa,and 27.5%,respectively.

关键词： high-entropy alloys microstructure mechanical properties wear resistance strengthening mechanisms

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Regulating the oxidation state of Pd to enhance the selective hydrogenation for 5-hydroxymethylfurfural

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Chinese Journal of Chemical Engineering 2024年第8期72卷 60-68页

作者： Xin li Yue ma Xuning Wang Jianguo Wu dong Cao Daojian Cheng State Key Laboratory of Organic-Inorganic Composites and College of Chemical Engineering Beijing University of Chemical TechnologyBeijing 100029China

The highly selective hydrogenation of 5-hydroxymethylfurfural to 2,5-dihydroxymethylfuran is an important reaction in the field of biomass hydrogenation,because it is a bridge between biomass resources and chemical ***,we precisely constructed carbon nitride supported Pd-based catalysts by a simple impregnation-reduction *** changing the reduction temperature,catalysts with different oxidation state could be precisely ***,the important correlation between the ratio of Pd^(0)/Pd^(2+)and catalytic activity is revealed during the selective hydrogenation of *** Pd/g—C_(3)N_(4)—300 catalyst with a Pd^(0)/Pd^(2+)ratio of 3/2 showed the highest catalytic activity,which could get 96.9%5-hydroxymethylfurfural conversion and 90.3%2,5-dihydroxymethylfuran *** density functional theory calculation revealed that the synergistic effect between Pd0and Pd2+in Pd/g—C_(3)N_(4)—300 system could boost the adsorption of the substrate and the dissociation of *** this work,we highlight the important correlation between metal oxidation state and catalytic activity,which provides valuable insights for the rational design of precious metal catalysts for hydrogenation reactions.

关键词： Pd/g-C_(3)N_(4) Selective hydrogenation 5-hydroxymethylfurfural 2,5-dihydroxymethylfuran Oxidation state

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