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Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

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Journal of Iron and Steel Research International 2024年第4期31卷 945-955页

作者： Yuan Zhang Xiang Liu chang-jun wang chang Liu School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research Institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Experimental Study on Dual-Wavelength Distributed Feedback Fiber Laser

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Photonic Sensors 2014年第3期4卷 225-229页

作者： Haifeng QI Zhiqiang SONG Jian GUO chang wang Jun chang Gangding PENG Shandong Key Laboratory of Optical Fiber Sensing Technologies Laser Institute of Shandong Academy of SciencesJinan 250014 China

Four distributed feedback fiber lasers with dual-wavelength operations were studied experimentally in detail. The laser characteristics of these distributed feedback fiber lasers （DFB-FLs） were investigated. The operation conditions for the dual-wavelength output are analyzed and presented. Through this study, the guidance of the design and fabrication of some dual-wavelength distributed feedback fiber lasers are provided.

关键词： Distributed feedback fiber laser dual wavelength phase shift optical fiber sensing

An Online Q-Learning Method for Linear-Quadratic Nonzero-Sum Stochastic Differential Games with Completely Unknown Dynamics

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Journal of Systems Science & Complexity 2024年第5期37卷 1907-1922页

作者： ZHANG Bao-Qiang wang Bing-chang CAO Ying School of Control Science and Engineering Shandong University

In this paper, the authors design a reinforcement learning algorithm to solve the adaptive linear-quadratic stochastic n-players non-zero sum differential game with completely unknown dynamics. For each player, a critic network is used to estimate the Q-function, and an actor network is used to estimate the control input. A model-free online Q-learning algorithm is obtained for solving this kind of problems. It is proved that under some mild conditions the system state and weight estimation errors can be uniformly ultimately bounded. A simulation with five players is given to verify the effectiveness of the algorithm.

关键词： Actor-critic algorithm model-free adaptive control nonzero-sum stochastic game reinforcement learning

From ore to MOF: A case of MIL-100(Fe) production from iron ore concentrates

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Progress in Natural Science:Materials International 2024年第01期34卷 66-73页

作者： Miao chang Chiyao Tang Chong-Chen wang Chen Zhao Beijing Key Laboratory of Functional Materials for Building Structure and Environment Remediation School of Environment and Energy Engineering Beijing University of Civil Engineering and Architecture

Within this work, iron ore concentrates instead of elemental iron Fe0and iron salts like Fe（NO3）3and FeCl3were selected as iron source to prepare MIL-100（Fe）(labeled as MIL-100（Fe）-ore). The corresponding synthesis cost is reduced to half of the MIL-100（Fe） produced from elemental iron and iron salts. As well, the unreacted iron ore concentrates can be easily separated from the as-prepared MIL-100（Fe）-ore by magnetic to facilitate the purification process, free of the strong acids to wash the residual iron. The as-obtained MIL-100（Fe）-ore with Langmuir surface area up to 2281.6 m2g-1displayed long-term chemical stability. Furthermore, the sorption capacity of MIL-100（Fe）-ore towards malachite green（MG） is up to 522.3 mg g-1at 25℃ and initial pH = 3.2, higher than that of MIL-100（Fe） yielded by conventional hydrothermal process. Finally, the production cost and life cycle assessment of MIL-100（Fe）-ore were compared with other traditional production procedures. The results revealed that our work greatly reduced the synthesis cost and enhanced the environmental sustainability.

关键词： Metal-organic framework Iron ore concentrates Adsorption Life cycle assessment

Energy-efficient reconfigurable processor for QC-LDPC via adaptive coding-voltage-frequency tuning

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 72-84页

作者： chang Libo Hu Yiqing Du Huimin wang Jihe School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China School of Computer Science Northwestern Polytechnical UniversityXi'an 710072China

To apply a quasi-cyclic low density parity check(QC-LDPC)to different scenarios,a data-stream driven pipelined macro instruction set and a reconfigurable processor architecture are proposed for the typical QC-LDPC *** data-level parallelism is improved by instructions to dynamically configure the multi-core computing ***,an intelligent adjustment strategy based on a programmable wake-up controller(WuC)is designed so that the computing mode,operating voltage,and frequency of the QC-LDPC algorithm can be *** adjustment can improve the computing efficiency of the *** QC-LDPC processors are verified on the Xilinx ZCU102 field programmable gate array(FPGA)board and the computing efficiency is *** experimental results indicate that the QC-LDPC processor can support two encoding lengths of three typical QC-LDPC algorithms and 20 adaptive operating modes of operating voltage and *** maximum efficiency can reach up to 12.18 Gbit/(s·W),which is more flexible than existing state-of-the-art processors for QC-LDPC.

关键词： quasi-cyclic low density parity check(QC-LDPC) dynamic voltage and frequency scaling(DVFS) reconfigurable computing coarse-grained reconfigurable arrays(CGRAs)

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The advantages of multi-level omics research on stem cell-based therapies for ischemic stroke

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Neural Regeneration Research 2024年第9期19卷 1998-2003页

作者： Yiqing wang Chuheng chang Renzhi wang Xiaoguang Li Xinjie Bao 4+4 Doctor Medical Program Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijingChina Department of Neurosurgery Peking Union Medical College HospitalPeking Union Medical CollegeChinese Academy of Medical SciencesBeijingChina Beijing Key Laboratory for Biomaterials and Neural Regeneration School of Biological Science and Medical EngineeringBeihang UniversityBeijingChina Department of Neurobiology School of Basic Medical SciencesCapital Medical UniversityBeijingChina

Stem cell transplantation is a potential therapeutic strategy for ischemic stroke. However, despite many years of preclinical research, the application of stem cells is still limited to the clinical trial stage. Although stem cell therapy can be highly beneficial in promoting functional recovery, the precise mechanisms of action that are responsible for this effect have yet to be fully elucidated. Omics analysis provides us with a new perspective to investigate the physiological mechanisms and multiple functions of stem cells in ischemic stroke. Transcriptomic, proteomic, and metabolomic analyses have become important tools for discovering biomarkers and analyzing molecular changes under pathological conditions. Omics analysis could help us to identify new pathways mediated by stem cells for the treatment of ischemic stroke via stem cell therapy, thereby facilitating the translation of stem cell therapies into clinical use. In this review, we summarize the pathophysiology of ischemic stroke and discuss recent progress in the development of stem cell therapies for the treatment of ischemic stroke by applying multi-level omics. We also discuss changes in RNAs, proteins, and metabolites in the cerebral tissues and body fluids under stroke conditions and following stem cell treatment, and summarize the regulatory factors that play a key role in stem cell therapy. The exploration of stem cell therapy at the molecular level will facilitate the clinical application of stem cells and provide new treatment possibilities for the complete recovery of neurological function in patients with ischemic stroke.

关键词： ischemic stroke mesenchymal stem cells metabolomics multilevel omics neural stem/progenitor cells neuroinflammation pathophysiology proteomics stem cell therapy transcriptomes

Gut microbial interactions based on network construction and bacterial pairwise cultivation

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Science China(Life Sciences) 2024年第8期67卷 1751-1762页

作者： Min-Zhi Jiang chang Liu chang Xu He Jiang Yulin wang Shuang-Jiang Liu State Key Laboratory of Microbial Technology Shandong UniversityQingdao 266000China State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center(EMRC)Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Association networks are widely applied for the prediction of bacterial interactions in studies of human gut ***,the experimental validation of the predicted interactions is challenging due to the complexity of gut microbiomes and the limited number of cultivated *** this study,we addressed this challenge by integrating in vitro time series network(TSN)associations and cocultivation of TSN taxon *** samples were collected and used for cultivation and enrichment of gut microbiome on YCFA agar plates for 13 *** cells were harvested for DNA extraction and metagenomic sequencing.A total of 198 metagenome-assembled genomes(MAGs)were *** dynamics of bacteria growing on the YCFA agar were used to infer microbial association *** experimentally validate the interactions of taxon pairs in networks,we selected 24 and 19 bacterial strains from this study and from the previously established human gut microbial biobank,respectively,for pairwise *** co-culture experiments revealed that most of the interactions between taxa in networks were identified as neutralism(51.67%),followed by commensalism(21.67%),amensalism(18.33%),competition(5%)and exploitation(3.33%).Genome-centric analysis further revealed that the commensal gut bacteria(helpers and beneficiaries)might interact with each other via the exchanges of amino acids with high biosynthetic costs,short-chain fatty acids,and/or *** also validated 12 beneficiaries by adding 16 additives into the basic YCFA medium and found that the growth of 66.7%of these strains was significantly *** approach provides new insights into the gut microbiome complexity and microbial interactions in association *** work highlights that the positive relationships in gut microbial communities tend to be overestimated,and that amino acids,short-chain fatty acids,and vitamins are contributed to the positive relationships.

关键词： human gut microbiome gut microbial pairwise interaction co-culture association network microbial community

An online value iteration method for linear-quadratic mean field social control with unknown dynamics

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Science China(Information Sciences) 2024年第4期67卷 38-39页

作者： Bing-chang wang Shumei LI Ying CAO School of Control Science and Engineering Shandong University

Mean field(MF) models have been widely applied to economics, control theory, and other fields. Its prominent feature is that the individual influence on the overall population is negligible and the impact of the entire system to the single agent is significant and cannot be ignored. As a classical problem in control theory, linear quadratic(LQ) control for MF models has been widely investigated(e.g., [1, 2]).

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Implementation of integrated nonlocal sensing for object shape and rotational speed

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 6-12页

作者： Zhenyu Guo Yunlong wang Zehong chang Jiawei wang Junliang Jia Pei Zhang Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic DevicesSchool of PhysicsXi’an Jiaotong UniversityXi’an 710049China

The expeditious acquisition of information pertaining to objects through the utilization of quantum technology has been a perennial issue of *** far,the efficient utilization of information from dynamic objects with limited resources remains a significant ***,we realize a nonlocal integrated sensing of the object's amplitude and phase information by combining digital spiral imaging with the correlated orbital angular momentum *** amplitude information is utilized for object identification,while the phase information enables us to determine the rotational *** demonstrate the nonlocal identification of a rotating object's shape,irrespective of its rotational symmetry,and introduce the concept of the correlated rotational Doppler effect,establishing a fundamental connection between this effect and the classical rotational Doppler effect,i.e.,that both rely on extracting crucial information from the spiral spectrum of *** present study highlights a promising pathway towards the realization of quantum remote sensing and imaging.

关键词： digital spiral imaging orbital angular momentum correlated rotational Doppler effect