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Effect of Artificial Cooling Extrusion on Microstructure and Mechanical Properties of Mg–Zn–Y Alloys

Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1115-1127页

作者： Qi-Yu Liao Da-Zhi Zhao Qi-Chi Le Wen-Xin Hu Yan-Chao Jiang wei-yang zhou Liang Ren Dan-Dan Li Zhao-yang Yin School of Materials Science and Engineering Northeastern UniversityShenyang110819China Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang110819China Key Laboratory of Lightweight Structural Materials Liaoning ProvinceNortheastern UniversityShenyang110819China Baotou Research Institute of Rare Earths Baotou014000China

Microstructure and mechanical properties of Mg–Zn–Y alloys with different Zn/Y atomic ratios with or without artificial cooling (AC) extrusion were systematically investigated in this work. The results show that bimodal microstructure consisting of submicron dynamic recrystallized (DRXed) grains with high fraction of low-angle grain boundaries (LAGBs) and elongated unDRXed grains was formed in Mg_(98.7)Zn_(1)Y_(0.3) alloy with AC extrusion. The AC process effectively limits the growth of precipitated phases, and large amount of nanoscale precipitates were dynamically precipitated during the extrusion process. AC extrusion could effectually refine the lamellar 14H LPSO phases and inhibit the transition from stacking faults to LSPO phases in Mg_(98)Zn_(1)Y_(1) alloy and the narrow LPSO phase in Mg_(98)Zn_(1)Y_(1)-AC alloy which could promote the nucleation of DRXed grains. The AC extrusion significantly improves the strength of Mg–Zn–Y alloys. Owing to AC extrusion, the strength improvement of Mg_(98.7)Zn_(1)Y_(0.3) alloy is mainly attributed to fine grain strengthening, dislocation strengthening, and nano-phases precipitation strengthening. After AC process, more fine grains and nano-phases jointly strengthen the Mg_(98)Zn_(1)Y_(1) alloy. The Mg_(98)Zn_(1)Y_(1) alloy obtains optimal mechanical properties after extrusion at 623 K, with ultimate tensile strength (UTS) of 406 MPa, yield strength (YS) of 388 MPa, and elongation (EL) of 5.6%.

关键词： Mg-Zn-Y Artificial cooling Extrusion Microstructure Mechanical properties

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Phase field modeling of ferroelastic variant switching in yttria-stabilized t'zirconia with strain gradient elasticity and interface tension

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Science China(Technological Sciences) 2024年第5期67卷 1443-1457页

作者： zhou QianQian wei YueGuang zhou YiChun yang Li College of Engineering BIC-ESATPeking UniversityBeijing100871China School of Advanced Materials and Nanotechnology Xidian UniversityXi’an710126China Frontier Research Center of Thin Films and Coatings for Device Applications Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an710126China

The 6–8 wt%yttria-stabilized zirconia with a tetragonal structure(t’-YSZ)is extensively employed in thermal barrier *** exceptional fracture toughness of t’-YSZ can be attributed to its distinctive ferroelastic toughening *** and interface tension play a critical role in ferroelastic variant switching at the micro-and *** paper presents an original thermodynamically consistent phase field(PF)theory for analyzing ferroelastic variant switching at the micro-and nano-scale of t’-*** theory incorporates strain gradient elasticity using higher-order elastic energy and interface tension tensor via geometric nonlinearity to represent biaxial tension resulting from interface ***,a mixed-type formulation is employed to implement the higher-order theory through the finite element *** an interface in equilibrium,the effects of strain gradient elasticity result in a more uniform distribution of stresses,whereas the presence of interface tension tensor significantly amplifies the stress magnitude at the *** introduction of an interface tension tensor increases the maximum value of stress at the interface by a factor of 4 to *** nucleation and evolution of variants at a pre-existing crack tip in a mono-phase t’-YSZ have also been *** strain gradient elasticity is capable of capturing the size effect of ferroelastic variant switching associated with microstructures in ***,when the grain size approaches that of the specimen,the critical load required for variant switching at the crack tip increases,resulting in greater dissipation of elastic energy during ferroelastic variant ***,the interface tension accelerates the evolution of *** presented framework exhibits significant potential in modeling ferroelastic variant switching at the micro-and nano-scale.

关键词： thermodynamics strain gradient elasticity interface tension phase field method ferroelastic variant switching

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A reweighted damped singular spectrum analysis method for robust seismic noise suppression

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Petroleum Science 2024年第3期21卷 1671-1682页

作者： wei-Lin Huang Yan-Xin zhou yang zhou wei-Jie Liu Ji-Dong Li State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China SINOPEC Petroleum Exploration and Production Research Institute Beijing102206China SINOPEC Geophysical Research Institute Nanjing211103jiangsuChina

(Multichannel)Singular spectrum analysis is considered as one of the most effective methods for seismic incoherent noise *** utilizes the low-rank feature of seismic signal and regards the noise suppression as a low-rank reconstruction ***,in some cases the seismic geophones receive some erratic disturbances and the amplitudes are dramatically larger than other *** presence of this kind of noise,called erratic noise,makes singular spectrum analysis(SSA)reconstruction unstable and has undesirable effects on the final *** robustify the low-rank reconstruction of seismic data by a reweighted damped SSA(RD-SSA)*** incorporates the damped SSA,an improved version of SSA,into a reweighted *** damping operator is used to weaken the artificial disturbance introduced by the low-rank projection of both erratic and random *** central idea of the RD-SSA method is to iteratively approximate the observed data with the quadratic norm for the first iteration and the Tukeys bisquare norm for the rest *** RD-SSA method can suppress seismic incoherent noise and keep the reconstruction process robust to the erratic *** feasibility of RD-SSA is validated via both synthetic and field data examples.

关键词： Singular spectrum analysis Damping operator Seismic erratic noise Seismic signal processing Robust low-rank reconstruction

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Fabrication and integration of photonic devices for phase-change memory and neuromorphic computing

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International Journal of Extreme Manufacturing 2024年第2期6卷 2-27页

作者： Wen zhou Xueyang Shen Xiaolong yang Jiangjing Wang wei Zhang Center for Alloy Innovation and Design(CAID) State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049People’s Republic of China

In the past decade,there has been tremendous progress in integrating chalcogenide phase-change materials(PCMs)on the silicon photonic platform for non-volatile memory to neuromorphic in-memory computing *** particular,these non von Neumann computational elements and systems benefit from mass manufacturing of silicon photonic integrated circuits(PICs)on 8-inch wafers using a 130 nm complementary metal-oxide semiconductor *** manufacturing based on deep-ultraviolet lithography and electron-beam lithography enables rapid prototyping of PICs,which can be integrated with high-quality PCMs based on the wafer-scale sputtering technique as a back-end-of-line *** this article,we present an overview of recent advances in waveguide integrated PCM memory cells,functional devices,and neuromorphic systems,with an emphasis on fabrication and integration processes to attain state-of-the-art device *** a short overview of PCM based photonic devices,we discuss the materials properties of the functional layer as well as the progress on the light guiding layer,namely,the silicon and germanium waveguide ***,we discuss the cleanroom fabrication flow of waveguide devices integrated with thin films and nanowires,silicon waveguides and plasmonic microheaters for the electrothermal switching of PCMs and mixed-mode ***,the fabrication of photonic and photonic–electronic neuromorphic computing systems is *** systems consist of arrays of PCM memory elements for associative learning,matrix-vector multiplication,and pattern *** large-scale integration,the neuromorphic photonic computing paradigm holds the promise to outperform digital electronic accelerators by taking the advantages of ultra-high bandwidth,high speed,and energy-efficient operation in running machine learning algorithms.

关键词： nanofabrication silicon photonics phase-change materials non-volatile photonic memory neuromorphic photonic computing

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Distributed Robust Optimal Dispatch of Regional Integrated Energy Systems Based on ADMM Algorithm with Adaptive Step Size

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 852-862页

作者： zhoujun Ma Yizhou zhou Yuping Zheng Li yang Zhinong wei the College of Energy and Electrical Engineering Hohai UniversityNanjing 211100China State Grid Jiangsu Electric Power Co. Ltd.Nanjing 210019China State Key Laboratory ofSmart Grid Protection and Control NARI Group CorporationNanjing 211106China

This paper proposes a distributed robust optimal dispatch model to enhance information security and interaction among the operators in the regional integrated energy system(RIES).Our model regards the distribution network and each energy hub(EH)as independent operators and employs robust optimization to improve operational security caused by wind and photovoltaic(PV)power output uncertainties,with only deterministic information exchanged across *** paper also adopts the alternating direction method of multipliers(ADMM)algorithm to facilitate secure information interaction among multiple RIES operators,maximizing the benefit for each ***,the traditional ADMM algorithm with fixed step size is modified to be adaptive,addressing issues of redundant interactions caused by suboptimal initial step size settings.A case study validates the effectiveness of the proposed model,demonstrating the superiority of the ADMM algorithm with adaptive step size and the economic benefits of the distributed robust optimal dispatch model over the distributed stochastic optimal dispatch model.

关键词： Regional integrated energy system(RIES) distributed optimization robust optimization operation security energy hub(EH)

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自体碎骨用于椎间植骨治疗腰椎间隙非特异性感染的疗效分析

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颈腰痛杂志 2024年第1期45卷 120-124页

作者：杨卫周张银刚苏薇李涛张波波边卫国韩学哲西安交通大学第一附属医院骨科陕西西安710061

目的探讨自体碎骨作为椎间植骨材料用于治疗腰椎间隙非特异性感染的临床疗效。方法收集了2010~2019年该科室采用自体碎骨用于椎体间植骨和后路手术治疗腰椎间隙非特异性感染病例24例,男性14例、女性10例,记录患者术前及末次随访时的白... 详细信息

目的探讨自体碎骨作为椎间植骨材料用于治疗腰椎间隙非特异性感染的临床疗效。方法收集了2010~2019年该科室采用自体碎骨用于椎体间植骨和后路手术治疗腰椎间隙非特异性感染病例24例,男性14例、女性10例,记录患者术前及末次随访时的白细胞计数、红细胞沉降率、C反应蛋白等实验室指标及手术中相关指标、术后并发症。测量术前及末次随访时的邻椎高度,记录病变椎间隙的融合时间。采用视觉模拟评分(visual analogue scale,VAS)、Oswestry功能障碍指数(Oswestry disability index,ODI)评估腰部疼痛及功能障碍程度。结果所有患者顺利完成手术。细菌培养结果:阳性8例(8/24,33.3%),其中革兰氏阳性菌5例:金黄色葡萄球菌4例,表皮葡萄球菌1例;革兰氏阴性菌3例,均为大肠埃希菌。ODI指数由术前(71.46±5.14)%下降至末次随访的(20.83±4.34)%,差异有统计学意义(P<0.05);VAS评分由术前(6.25±1.36)分下降至末次随访的(2.63±0.88)分,差异有统计学意义(P<0.05)。所有病例均获得椎体间骨性融合。结论自体碎骨作为椎间植骨材料应用于后路手术治疗非特异性腰椎间隙感染,一方面可以避免取髂骨术带来的损伤和并发症,另一方面能够维持和恢复椎体间高度,获得椎体间骨性融合,取得良好的临床效果。

关键词：腰椎感染脊柱融合术治疗结果

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Multi-Strategy Assisted Multi-Objective Whale Optimization Algorithm for Feature Selection

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1563-1593页

作者： Deng yang Chong zhou Xuemeng wei Zhikun Chen Zheng Zhang School of Information Engineering Hebei GEO UniversityShijiazhuang050031China Faculty of Science University of AlbertaEdmontonT2N1N4Canada College of Resources and Environment Beibu Gulf UniversityQinzhou535011China Clinical Laboratory The Frist Hospital of Hebei Medical UniversityShijiazhuang050000China

In classification problems,datasets often contain a large amount of features,but not all of them are relevant for accurate *** fact,irrelevant features may even hinder classification *** selection aims to alleviate this issue by minimizing the number of features in the subset while simultaneously minimizing the classification error ***-objective optimization approaches employ an evaluation function designed as an aggregate function with a parameter,but the results obtained depend on the value of the *** eliminate this parameter’s influence,the problem can be reformulated as a multi-objective optimization *** Whale Optimization Algorithm(WOA)is widely used in optimization problems because of its simplicity and easy *** this paper,we propose a multi-strategy assisted multi-objective WOA(MSMOWOA)to address feature *** enhance the algorithm’s search ability,we integrate multiple strategies such as Levy flight,Grey Wolf Optimizer,and adaptive mutation into ***,we utilize an external repository to store non-dominant solution sets and grid technology is used to maintain *** on fourteen University of California Irvine(UCI)datasets demonstrate that our proposed method effectively removes redundant features and improves classification *** source code can be accessed from the website:https://***/zc0315/MSMOWOA.

关键词： Multi-objective optimization whale optimization algorithm multi-strategy feature selection

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Electromagnetic scattering and imaging simulation of extremely large-scale sea-ship scene based on GPU parallel technology

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Journal of Electronic Science and Technology 2024年第2期22卷 16-23页

作者： Cheng-wei Zhang Zhi-Qin Zhao wei yang Li-Lai zhou Hai-Yu Zhu Southwest China Institute of Electronic Technology Chengdu610036China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China Tencent Company Shenzhen518054China

Aiming to solve the bottleneck problem of electromagnetic scattering simulation in the scenes of extremely large-scale seas and ships,a high-frequency method by using graphics processing unit(GPU)parallel acceleration technique is *** the implementation of different electromagnetic methods of physical optics(PO),shooting and bouncing ray(SBR),and physical theory of diffraction(PTD),a parallel computing scheme based on the CPU-GPU parallel computing scheme is realized to balance computing ***,a multi-GPU framework is further proposed to solve the computational difficulty caused by the massive number of ray tubes in the ray tracing *** using the established simulation platform,signals of ships at different seas are simulated and their images are achieved as *** is shown that the higher sea states degrade the averaged peak signal-to-noise ratio(PSNR)of radar image.

关键词： Multi graphics processing unit Radar imaging Sea-ship Shooting and bouncing rays

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Micromechanism and mathematical model of stress sensitivity in tight reservoirs of binary granular medium

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Petroleum Science 2024年第3期21卷 1780-1795页

作者： Jian-Bang Wu Sheng-Lai yang Qiang Li Kun yang Can Huang Dao-Ping Lv wei zhou State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China Laboratoire de G eologie Ecole Normale Sup erieure/CNRS UMR8538PSL Research UniversityParis75005France Research Institute of Exploration and Development Xinjiang Oilfield CompanyKaramay834000XinjiangChina

Research on reservoir rock stress sensitivity has traditionally focused on unary granular structures,neglecting the binary nature of real reservoirs,especially tight *** the stresssensitive behavior and mathematical characterization of binary granular media remains a challenging *** this study,we conducted online-NMR experiments to investigate the permeability and porosity evolution as well as stress-sensitive control mechanisms in tight sandy conglomerate *** results revealed stress sensitivity coefficients between 0.042 and 0.098 and permeability damage rates ranging from 65.6%to 90.9%,with an average pore compression coefficient of 0.0168—0.0208 MPa ***-scale compression occurred in three stages:filling,compression,and compaction,with matrix pores playing a dominant role in pore *** stress sensitivity of binary granular media was found to be influenced by the support structure and particle *** stress sensitivity was associated with small fine particle size,high fines content,high uniformity coefficient of particle size,high plastic deformation,and low Young's ***-supported samples exhibited a high irreversible permeability damage rate(average=74.2%)and stress sensitivity coefficients(average=0.089),with pore spaces more *** contrast,grain-supported samples showed low stress sensitivity coefficients(average=0.021)at high stress *** on the experiments,we developed a mathematical model for stress sensitivity in binary granular media,considering binary granular properties and nested interactions using Hertz contact deformation and Poiseuille *** describing the change in activity content of fines under stress,we characterized the non-stationary state of compressive deformation in the binary granular structure and classified the reservoir into three *** model was applied for production prediction using actual data from the Mahu reservoir in China,showing that the e

关键词： Stress sensitivity Binary granular medium Tight reservoir Online-NMR Reservoir energy retention rate

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Current status and challenges in the application of microbial PHA particles

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Particuology 2024年第4期87卷 286-302页

作者： Jiaxuan Liu Ziqi zhou Haoru Li Xinyu yang Zeyu Wang jian Xiao Dai-Xu wei Key Laboratory of Resource Biology and Biotechnology in Western China Ministry of EducationSchool of MedicineDepartment of Life Sciences and MedicineNorthwest UniversityXi'an710069China School of Clinical Medicine Qujing Medical CollegeQujing655000China School of Physics and Electronic Information Shangrao Normal UniversityShangrao334001China Zigong Affiliated Hospital of Southwest Medical University Zigong Psychiatric Research CenterZigong Institute of Brain ScienceZigong643002China

Polyhydroxyalkanoates(PHAs)are diversiform biopolyesters with a similar structure and different side chain groups,synthesized by a variety of *** to their excellent biodegradability and biocompatibility,PHAs have been used for many applications,including medical implants,antibacterial agents and ***-architecture is an emerging area for the use of *** review summarizes the current status and challenges of PHAs-based particles on the micro-and nano-scale,including their production,degradation,biological safety,and surface *** also focus on the applications of PHA particles in drug delivery systems,environment protection,tissue engi-neering,vaccine engineering,food science,biotechnology and ***,the future development trends of PHAs-based particles are prospected.

关键词： Polyhydroxyalkanoates(PHAs) Particles Synthetic biology Tissue engineering

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