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Study on the hydrogen absorption properties of a YGdTbDyHo rare-earth high-entropy alloy

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 127-135页

作者： tongyue Li Ziliang xie Wenjiao Zhou Huan tong Dawen Yang Anjia Zhang Yuan Wu Xiping Song State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Whole Win(Beijing)Materials Sci.&Tech.Co. Ltd.Beijing 100083China

This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),*** indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed *** hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase *** alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period *** reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral *** results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.

关键词： rare-earth high-entropy alloy hydrogen absorption capacity pressure–composition–temperature curves kinetics

Heterogeneous Network Selection Optimization Algorithm Based on a Markov Decision Model

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China Communications 2020年第2期17卷 40-53页

作者： Jianli xie wenjuan Gao Cuiran Li School of Electronic and Information Engineering Lanzhou Jiaotong University

A network selection optimization algorithm based on the Markov decision process(MDP)is proposed so that mobile terminals can always connect to the best wireless network in a heterogeneous network *** the different types of service requirements,the MDP model and its reward function are constructed based on the quality of service(QoS)attribute parameters of the mobile users,and the network attribute weights are calculated by using the analytic hierarchy process(AHP).The network handoff decision condition is designed according to the different types of user services and the time-varying characteristics of the network,and the MDP model is solved by using the genetic algorithm and simulated annealing(GA-SA),thus,users can seamlessly switch to the network with the best long-term expected reward *** results show that the proposed algorithm has good convergence performance,and can guarantee that users with different service types will obtain satisfactory expected total reward values and have low numbers of network handoffs.

关键词： heterogeneous wireless networks Markov decision process reward function genetic algorithm simulated annealing

Construction and Functionalization of Highly Strained N-Doped Zigzag Hydrocarbon Belts

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CCS Chemistry 2023年第1期5卷 117-123页

作者： ming xie Shuo tong Mei-Xiang Wang MOE Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084

Recent years have witnessed breakthroughs in the study of zigzag hydrocarbon ***,the synthesis of heterocycle-containing zigzag molecular belts remains very rare and challenging despite their interesting structures and potential applications in chemistry and materials ***,we report the expeditious construction of a highly strained belt[4]arene[4](1,4-dihydropyridine)structure using the fjords-stitching *** synthesis comprised four-fold abnormal m-bromination of four Npivaloylaniline units and Pd_(2)(dba)_(3)/4-Me_(2)NC_(6)H_(4)Pt Bu_(2)-catalyzed intramolecular C-N bond-forming *** functionalization through Narylations produced a variety of tetraza-embedded octahydrobelt[8]*** oxidation of p-methoxyphenyl-substituted belt[4]arene[4](1,4-dihydropyridine)with Ag[Al(O^(t)Bu^(F))^(4)]yielded a singlet diradical dication N-doped zigzag belt.

关键词： zigzag molecular belt cyclacene octahydrobeltarenepyridine meta-bromination of Nacylaniline palladium-catalyzed C-N bond formation diradical dication salt

Patch-based variational image approximation

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Science China(Information Sciences) 2017年第3期60卷 78-87页

作者： Hao xie Ruofeng tong Artificial Intelligence Institute Zhejiang University College of New Media Zhejiang University of Media and Communications

Vector graphic gives us a new solution to the representation of raster images. Among many types of vectorized representations, the most popular is mesh representation, which inherits the benefits of vector graphics. Inspired by mesh, we propose a novel patch-based representation for raster images, in which pixels are partitioned into regions, and pixels belonging to the same region are converted into a 3D point cloud and approximated by a 3D planar patch with proper boundaries in a variational way. The resulting patches are then encoded via a half-edge structure for storage. The key point is that the vertices of boundaries are not located on the very positions of sample points, i.e. converted pixels, but dependent on the optimal position of the patch,which theoretically reduces the fitting errors. Experiments show that our algorithm produces better results.

关键词： image approximation vector graphics image representation plane optimization boundary extrac tion

Image meshing via hierarchical optimization

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Frontiers of Information Technology & Electronic Engineering 2016年第1期17卷 32-40页

作者： Hao xie Ruo-feng tong Institute of Artificial Intelligence Zhejiang University

Vector graphic, as a kind of geometric representation of raster images, has many advantages, e.g.,definition independence and editing facility. A popular way to convert raster images into vector graphics is image meshing, the aim of which is to find a mesh to represent an image as faithfully as possible. For traditional meshing algorithms, the crux of the problem resides mainly in the high non-linearity and non-smoothness of the ob jective,which makes it difficult to find a desirable optimal solution. To ameliorate this situation, we present a hierarchical optimization algorithm solving the problem from coarser levels to finer ones, providing initialization for each level with its coarser ascent. To further simplify the problem, the original non-convex problem is converted to a linear least squares one, and thus becomes convex, which makes the problem much easier to solve. A dictionary learning framework is used to combine geometry and topology elegantly. Then an alternating scheme is employed to solve both parts. Experiments show that our algorithm runs fast and achieves better results than existing ones for most images.

关键词： Image meshing, Hierarchical optimization, Convexification

Unraveling the significance of cobalt on transformation kinetics,crystallography and impact toughness in high-strength steels

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 380-390页

作者： Yishuang Yu Jingxiao Zhao Xuelin Wang Hui Guo Zhenjia xie Chengjia Shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

This work reveals the significant effects of cobalt(Co)on the microstructure and impact toughness of as-quenched highstrength steels by experimental characterizations and thermo-kinetic *** results show that the Co-bearing steel exhibits finer blocks and a lower ductile-brittle transition temperature than the steel without ***,the Co-bearing steel reveals higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to *** improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by the V1/V2 variant ***,the addition of Co induces a larger transformation driving force and a lower bainite start temperature(BS),thereby contributing to the refinement of blocks and the increase of the V1/V2 variant *** findings would be instructive for the composition,microstructure design,and property optimization of high-strength steels.

关键词： high-strength steel cobalt transformation kinetics crystallography impact toughness

Lifespan of Solutions to MHD Boundary Layer Equations with Analytic Perturbation of General Shear Flow

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Acta Mathematicae Applicatae Sinica 2019年第1期35卷 209-229页

作者： Feng xie tong YANG School of Mathematical Sciences and LSC-MOE Shanghai Jiao Tong University Department of Mathematics City University of Hong Kong School of Mathematical Sciences Shanghai Jiao Tong University

In this paper, we consider the lifespan of solution to the MHD boundary layer system as an analytic perturbation of general shear flow. By using the cancellation mechanism in the system observed in [12], the lifespan of solution is shown to have a lower bound in the order of ε^(-2-) if the strength of the perturbation is of the order of ε. Since there is no restriction on the strength of the shear flow and the lifespan estimate is larger than the one obtained for the classical Prandtl system in this setting, it reveals the stabilizing effect of the magnetic field on the electrically conducting fluid near the boundary.

关键词： MHD boundary layer analytic perturbation lifespan estimate shear flow

DYNAMIC MODELING AND ACTIVE CONTROL OF FLEXIBLE PLATE BASED ON THE INPUT-OUTPUT DATA

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Acta Mechanica Solida Sinica 2013年第3期26卷 255-262页

作者： Yong xie tong Zhao Guoping Cai Department of Engineering Mechanics State Key Laboratory of Ocean EngineeringShanghai Jiaotong University

This paper studies the low-order dynamic modeling and active control of a flexible plate and provides experimental verification. First based on the input-output data of the sys- tem, the Markov parameters of the system are identified using the method of observer/Kalman filter identification （OKID）. Then a low-order state-space model is built using the eigensystem realization algorithm （ERA）. Finally, a linear quadratic Gaussian （LQG） controller is designed based on the low-order state-space model. Experimental results have proved the effectiveness and feasibility of the research.

关键词： flexible plate OKID ERA active control experiment

Electrochemical, quantum chemical and SEM investigation of the inhibiting effect and mechanism of ciprofloxacin, norfloxacin and ofloxacin on the corrosion for mild steel in hydrochloric acid

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Science China Chemistry 2008年第10期51卷 928-936页

作者： PANG XueHui GUO wenjuan LI WeiHua xie JianDong HOU BaoRong School of Chemistry and Chemical Engineering University of JinanJinan 250022China Institute of Oceanology Chinese Academy of SciencesQingdao 266071China Institute of Design and Research of Shandong Jianzhu University Jinan 250013China

The inhibiting effect and mechanism of 1-cyclopropyl-6-fluoro-1,4-dihydro -4-oxo-7-(1-piperazinyl) -3- quinoline carboxylicacid(ciprofloxacin), 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (norfloxacin) and (?)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7- oxo-7 H-pyrido(1,2,3-de)-1,4- benzoxazine-6 carboxylic acid (ofloxacin) on the corrosion of mild steel in 1 mol/L HCl have been studied using electrochemical method, quantum chemical method and SEM at 303 K. The potentiodynamic results showed that these compounds suppressed both cathodic and an-odic processes of mild steel corrosion in 1 mol/L HCl. The impedance spectroscopy showed that Rp values increased, and Cdl values decreased with the rising of the working concentration. Quantum chemical calculation showed that there was a positive correlation between some inhibitors structure properties and the inhibitory efficiency. The inhibitors function through adsorption followed Langmuir isotherm, and chemisorption made more contribution to the adsorption of the inhibitors on the steel surface compared with physical adsorption. SEM analysis suggested that the metal had been protected from aggressive corrosion because of the addition of the inhibitors.

关键词： inhibition mild steel polarization electrochemical impedance spectroscopy SEM