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Effect of Annealing Temperature and Strain Rate on Mechanical Property of a Selective Laser Melted 316L Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2022年第5期35卷 773-789页

作者： Hua-Zhen Jiang Zheng-Yang Li tao Feng peng-yue Wu Qi-Sheng Chen Shao-Ke Yao Jing-Yu Hou School of Engineering Science University of Chinese Academy of SciencesBeijing100190China Institute of Mechanics Chinese Academy of SciencesBeijing100190China Beijing E-Plus-3D Technology Co. LTDBeijing102299China

In the present work,316 L stainless steel specimens are fabricated by selective laser melting(SLM)via optimized laser process *** effects of two extrinsic factors,i.e.,strain rate and annealing temperature,on the mechanical performance of SLM-processed parts are *** two intrinsic factors,namely strain rate sensitivity m and work hardening exponent n,which control the tensile properties of the as-built samples,are *** structure characterizations show that cellular structure and crystalline grain exhibit apparently different thermal stability at 873 *** testing reveals that the yield strength decreases from 584±16 MPa to 323±2 MPa,while the elongation to failure increases from(46±1)%to(65±2)%when annealing temperature varies from 298 K to 1328 *** n value increases from 0.13 to 0.33 with the increase in annealing *** to the presence of fine cellular structures and high relative density achieved in as-printed 316 L samples,a strong dependence between tensile yield strength and strain rate is *** addition,the strain rate sensitivity of the SLM-produced 316 L part(m=0.017)is much larger than that of conventional coarse-grained part(m=0.006),whereas the n value increases slightly from 0.097 to 0.14 with increasing strain rate.

关键词： Selective laser melting 316L stainless steel Heat treatment Strain hardening behaviors Mechanical property

Removal of Pb(Ⅱ) from aqueous solutions using waste textiles/poly(acrylic acid) composite synthesized by radical polymerization technique

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Journal of Environmental Sciences 2018年第5期30卷 368-377页

作者： tao Zhou Fafa Xia yue Deng Youcai Zhao The State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and Engineering Tongji University

Waste textiles（WTs） are the inevitable outcome of human activity and should be separated and recycled in view of sustainable development. In this work, WT was modified through grafting with acrylic acid（AA） via radical polymerization process using ceric ammonium nitrate（CAN） as an initiator and microwave and/or UV irradiation as energy supply. The acrylic acid-grafted waste textiles（WT-g-AA） thus obtained was then used as an adsorbent to remove Pb（Ⅱ） from Pb（Ⅱ）-containing wastewater. The effects of p H, initial concentrations of Pb（Ⅱ） and adsorbent dose were investigated, and around 95% Pb（Ⅱ） can be removed from the aqueous solution containing 10 mg/L at p H 6.0–8.0. The experimental adsorption isotherm data was fitted to the Langmuir model with maximum adsorption capacity of35.7 mg Pb/g WT-g-AA. The Pb-absorbed WT-g-AA was stripped using dilute nitric acid solution and the adsorption capacity of Pb-free material decreased from 95.4%（cycle 1） to91.1%（cycle 3）. It was considered that the WT-g-AA adsorption for Pb（Ⅱ） may be realized through the ion-exchange mechanism between ／COOH and Pb（Ⅱ）. The promising results manifested that WT-g-AA powder was an efficient, eco-friendly and reusable adsorbent for the removal of Pb（Ⅱ） from wastewater.

关键词： Adsorption Pb(Ⅱ) Waste textiles Graft copolymefization

EXPERIMENTAL STUDY OF CONDENSATION HEAT TRANSFER CHA- RACTERISTICS OF HORIZONTAL TUBE BUNDLES IN VACUUM STATES

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Journal of Hydrodynamics 2012年第4期24卷 628-634页

作者： CHENG Shen SUN Feng-zhong SHI yue-tao School of Energy Source and Power Engineering Shandong UniversityJinan 250061China

TO develop an excellent heat transfer element under the vacuum condition, experiments about the heat transfer performance of horizontal tube bundles of different materials under various vacuum conditions were carried out, including the stainless steel tube, the brass tube, the Ni-based implanted steel tube and the ion implanted brass tube. The relative trends show that the condensation heat transfer coefficient and the overall heat transfer coefficient of bundles of four materials all increase with the vacuum degree, especially, those of the Ni-based implanted steel tube and the ion implanted brass tube. Under a high vacuum condition （0.07 MPa）, the condensation heat transfer coefficient of the Ni-based implanted steel tube bundle is about 1.4 times of that of the stainless steel tube bundle, the condensation heat transfer coefficient of the ion implanted brass tube bundle is found to be about 1.3 times of that of the common brass tube bundle. Therefore, according to the condensation heat transfer characteristics studied under high vacuum conditions, it is believed that a dropwise condensation is partly achieved on the surface of these two implanted tube bundles, and the ion implantation is shown to be an effective method to achieve the dropwise condensation. Based on this study, it is believed that the Ni-based steel tube may replace the brass tube, which is more expensive as a heat transfer component.

关键词： vacuum heat transfer characteristics condensation heat transfer coefficient dropwise condensation

Distributed bias-compensated normalized least-mean squares algorithms with noisy input

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Science China(Information Sciences) 2018年第11期61卷 193-207页

作者： Lu FAN Lijuan JIA Ran tao yue WANG School of Information and Electronics Beijing Institute of Technology

In this paper, we study the problem of distributed normalized least-mean squares(NLMS) estimation over multi-agent networks, where all nodes collaborate to estimate a common parameter of *** consider the situations that all nodes in the network are corrupted by both input and output noise. This yields into biased estimates by the distributed NLMS algorithms. In our analysis, we take all the noise into consideration and prove that the bias is dependent on the input noise variance. Therefore, we propose a bias compensation method to remove the noise-induced bias from the estimated results. In our development, we first assume that the variances of the input noise are known a priori and develop a series of distributed-based bias-compensated NLMS(BCNLMS) methods. Under various practical scenarios, the input noise variance is usually unknown a priori, therefore it is necessary to first estimate for its value before bias removal. Thus, we develop a real-time estimation method for the input noise variance, which overcomes the unknown property of this noise. Moreover, we perform some main analysis results of the proposed distributed BCNLMS algorithms. Furthermore, we illustrate the performance of the proposed distributed bias compensation method via graphical simulation results.

关键词： distributed parameter estimation normalized least-mean squares bias-compensated algorithms

The role of prior in image based 3D modeling： a survey

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Frontiers of Computer Science 2017年第2期11卷 175-191页

作者： Hao ZHU Yongming NIE tao yue Xun CAO Lab for Computational Imaging Technology and Engineering School of Electronic Science and Engineering Nanjing University Nanjing 210023 China

The prior knowledge is the significant supple- ment to image-based 3D modeling algorithms for refining the fragile consistency-based stereo. In this paper, we review the image-based 3D modeling problem according to prior cate- gories, i.e., classical priors and specific priors. The classical priors including smoothness, silhouette and illumination are well studied for improving the accuracy and robustness of the 3D reconstruction. In recent years, various specific priors which take advantage of Manhattan rule, geometry template and trained category features have been proposed to enhance the modeling performance. The advantages and limitations of both kinds of priors are discussed and evaluated in the paper. Finally, we discuss the trend and challenges of the prior studies in the future.

关键词： prior information consistency-based stereo,smoothness illumination silhouette specific prior

Distributed incremental bias-compensated RLS estimation over multi-agent networks

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Science China(Information Sciences) 2017年第3期60卷 153-167页

作者： Jian LOU Lijuan JIA Ran tao yue WANG School of Information and Electronics Beijing Institute of Technology

In this paper, we study the problem of distributed bias-compensated recursive least-squares(BCRLS) estimation over multi-agent networks, where the agents collaborate to estimate a common parameter of interest. We consider the situation where both input and output of each agent are corrupted by unknown additive noise. Under this condition, traditional recursive least-squares(RLS) estimator is biased, and the bias is induced by the input noise variance. When the input noise variance is available, the effect of the noise-induced bias can be removed at the expense of an increase in estimation variance. Fortunately, it has been illustrated that distributed collaboration between agents can effectively reduce the variance and can improve the stability of the estimator. Therefore, a distributed incremental BC-RLS algorithm and its simplified version are proposed in this paper. The proposed algorithms can collaboratively obtain the estimates of the unknown input noise variance and remove the effect of the noise-induced bias. Then consistent estimation of the unknown parameter can be achieved in an incremental fashion. Simulation results show that the incremental BC-RLS solutions outperform existing solutions in some enlightening ways.

关键词： distributed parameter estimation bias compensation incremental schemes recursive least-squares multi-agent networks

Facile synthesis of molybdenum carbide nanoparticles in situ decorated on nitrogen-doped porous carbons for hydrogen evolution reaction

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Journal of Energy Chemistry 2019年第5期28卷 78-84页

作者： Jin-tao Ren yue-Jun Song Zhong-Yong Yuan National Institute for Advanced Materials School of Materials Science and EngineeringNankai UniversityTianjin 300350China Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)Nankai UniversityTianjin 300071China

Molybdenum-based electrocatalysts are promising candidates of platinum (Pt)-based materials in electrocatalyzing hydrogen evolution reaction (HER), due to their cost-efficient and resembled electronic properties. Reported herein is the preparation of molybdenum carbide nanoparticles uniformly decorated on nitrogen-modified carbons (Mo2C/NC) through the carbonization of Mo-based polymers under hydrogen atmosphere by using poly(p-phenylenediamine) and ammonium heptamolybdate polymer analogue as precursors. And the molybdenum nitride nanoparticles loaded on porous N-doped carbons (Mo2N/NC) are also fabricated by calcination the polymer precursors in nitrogen gas. The Mo2C/NC shows more excellent electrocatalytic activity than Mo2N/NC in 0.5 M H2SO4, together with robust long-term durability. The well-crystalline nanoparticles and the increased electron conductivity are the main characters responded for the high catalytic efficiency of the fabricated electrocatalysts. This easily fabrication procedure may provide a facile route to prepare non-noble metal carbide/nitride catalysts featuring wellengineered structural and textural peculiarities for realistic energy conversion system.

关键词： Molybdenum carbide Molybdenum nitride Nitrogen-doped carbon Hydrogen evolution reaction Electrocatalysis

Visualization Experiment and Numerical Analysis of Cavitation Flow Characteristics in Diesel Fuel Injector Control Valve with Different Structure Design

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Journal of Thermal Science 2021年第1期30卷 76-87页

作者： MA Haoyuan ZHANG Tong AN Qingsong tao Yuhao XU yue School of Mechanical Engineering Tianjin UniversityTianjin 300350China Key Lab of Efficient Utilization of Low and Medium Grade Energy Tianjin 300350China Shanghai Marine Diesel Engine Research Institute Shanghai 201108China

Increasing the injection pressure has been proven an effective method to enhance performance and reduce pollutant of diesel *** the increase of the injection pressure,the cavitation damage problem inside common rail fuel injector is more significant,which has direct influences on reliability of diesel *** the most studies so far have focused on cavitation occurred in injector nozzle and its atomization characteristics,few researchers studied the cavitation phenomenon in fuel injector control *** due to the complexity of flow field and difficulty of experiment,the cavitation in control valve could not be fully described by existing *** this paper,the two-dimensional visualization experiment and numerical simulation of control valve was implemented to acquire the image of cavitation intuitively and validate the simulation method and *** a new structure design of control valve named convergent model was presented for *** origin model and convergent model with different valve lifts were simulated in three *** results showed that the sheet cavitation occurred at the surface of seal cone and steel ball then turned to cloud cavitation in downstream *** intensity of cavitation increased with the increase of valve *** model could efficiently reduce the cavitation intensity near the seal *** research could provide references for engineering optimization design of control valve.

关键词： diesel engine fuel injector control valve cavitation

High-temperature magnetic properties of anisotropic Mn Bi/Nd Fe B hybrid bonded magnets

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Rare Metals 2016年第6期35卷 471-474页

作者： Dong-tao Zhang peng-Fan Wang Ming yue Wei-Qiang Liu Jiu-Xing Zhang Jennifer Anand Sundararajan You Qiang College of Materials Science and Engineering Beijing University of Technology Physics Department University of Idaho

Anisotropic MnBi/NdFeB （MnBi contents of 0 wt%, 20 wt%, 40 wt%, 60 wt%, 80 wt%, and 100 wt%） hybrid bonded magnets were prepared by molding compression using MnBi powders and commercial hydro-genation disproportionation desorption and recombination （HDDR） NdFeB powders. Magnetic measurements at room temperature show that with MnBi content increasing, the magnetic properties of the MnBi/NdFeB hybrid bonded magnets all decrease gradually, while the density of the hybrid magnets improves almost linearly. In a temperature range of 293-398 K, the coercivity temperature coefficient of the hybrid magnets improves gradually from -0.59 %.K^-1 for the pure NdFeB bonded magnet to -0.32 %.K^-1 for the hybrid bonded magnet with 80 wt% MnBi, and the pure MnBi bonded magnet exhibits a positive coercivity temperature coefficient of 0.61%-K^-1.

关键词： Hybrid bonded magnet NdFeB MnBi Coercivity temperature coefficient