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Microstructure modification and precipitation strengthening for Mg−6Zn−1Mn−4Sn−0.5Ca through extrusion and aging treatment

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Transactions of Nonferrous Metals Society of China 2020年第10期30卷 2650-2657页

作者： Xia CHEN Ding-fei ZHANG Yang ZHAO jing-kai feng Bin JIANG Fu-sheng PAN College of Materials Science and Engineering Chongqing UniversityChongqing 400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China Chongqing Academy of Science and Technology Chongqing 401123China

The microstructure revolution and mechanical properties of as-extruded and peak-aged Mg−6Zn−1Mn−4Sn−0.5Ca(ZMT614−0.5Ca)alloy were studied by OM,SEM,TEM,hardness testing and tensile *** results showed that the as-cast ZMT614−0.5Ca alloy mainly consisted of α-Mg,Mg−Zn and CaMgSn *** hot extrusion process effectively refined the microstructure and led to a completely dynamic recrystallized *** average grain size of as-extruded alloy was^4.85μ*** solution treatment,remained CaMgSn with high melting point played a significant role in pinning effect and impeding the migration of grain *** aging treatment,peak-aged ZMT614−0.5Ca alloy exhibited a good combination of strength and ductility,with yield strength,ultimate tensile strength and elongation being 338 MPa,383 MPa and 7.5%,*** yield strength of the alloy increased significantly by around 36%compared with that in as-extruded condition,which should be attributed to the precipitation strengthening of β'phase.

关键词： Mg−6Zn−1Mn−4Sn−0.5Ca extrusion aging microstructure precipitation strengthening

Liver resection versus intensity-modulated radiation therapy for treatment of hepatocellular carcinoma with hepatic vein tumor thrombus:a propensity score matching analysis

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Hepatobiliary Surgery and Nutrition 2021年第5期10卷 646-660,I0017-I0021页

作者： Zhen-Hua Chen Xiu-Ping Zhang Shuang feng jing-kai feng Zong-Tao Chai Wei-Xing Guo Jie Shi Wan Yee Lau Yan Meng Shu-Qun Cheng Department of Hepatic Surgery VI Eastern Hepatobiliary Surgery HospitalSecond Military Medical UniversityShanghaiChina Department of Hepatobiliary and Pancreatic Surgical Oncology The First Medical Center of Chinese People’s Liberation Army(PLA)General HospitalBeijingChina Department of Radiotherapy Eastern Hepatobiliary Surgery HospitalSecond Military Medical UniversityShanghaiChina Faculty of Medicine The Chinese University of Hong KongHong KongChina

Background:The presence of hepatic vein tumor thrombus(HVTT)is a major determinant of survival outcomes in hepatocellular carcinoma(HCC)*** study compared survival outcomes between liver resection(LR)and intensity-modulated radiation therapy(IMRT)in HCC patients with ***:Data from patients who underwent LR or IMRT for HCC with HVTT at the Eastern Hepatobiliary Surgery Hospital were retrospectively *** survival outcomes were compared before and after propensity score matching(PSM).Results:Three hundred and seven HCC patients with HVTT who underwent either LR(n=140)or IMRT(n=167)were *** matched 82 pairs of *** overall survival(OS)and recurrence-free survival(RFS)rates were significantly higher for patients in the LR group than those in the IMRT *** subgroup analysis,significantly better survival outcomes were obtained after LR than IMRT in patients with peripheral type of HVTT(pHVTT)and major type of HVTT(mHVTT).However,similar survival outcomes were obtained after LR and IMRT when the HVTT had developed into inferior vena cava tumor thrombus(IVCTT).Conclusions:LR resulted in significantly better survival outcomes in HCC patients with HVTT when compared to *** the HVTT had developed IVCTT,LR and IMRT resulted in similarly bad survival outcomes.

关键词： Hepatocellular carcinoma(HCC) hepatic vein tumor thrombus(HVTT) liver resection(LR) radiotherapy

Plasma-assisted ammonia synthesis under mild conditions for hydrogen and electricity storage:Mechanisms,pathways,and application prospects

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Frontiers in Energy 2024年第4期18卷 418-435页

作者： feng GONG Yuhang jing Rui XIAO Key Laboratory of Energy Thermal Conversion and Process Measurement and Control of the Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China

Ammonia,with its high hydrogen storage density of 17.7 wt.%(mass fraction),cleanliness,efficiency,and renewability,presents itself as a promising zero-carbon ***,the traditional Haber−Bosch(H−B)process for ammonia synthesis necessitates high temperature and pressure,resulting in over 420 million tons of carbon dioxide emissions annually,and relies on fossil fuel *** contrast,dielectric barrier discharge(DBD)plasma-assisted ammonia synthesis operates at low temperatures and atmospheric pressures,utilizing nitrogen and hydrogen radicals excited by energetic electrons,offering a potential alternative to the H−B *** method can be effectively coupled with renewable energy sources(such as solar and wind)for environmentally friendly,distributed,and efficient ammonia *** review delves into a comprehensive analysis of the low-temperature DBD plasma-assisted ammonia synthesis technology at atmospheric pressure,covering the reaction pathway,mechanism,and catalyst system involved in plasma nitrogen *** from current research,it evaluates the economic feasibility of the DBD plasmaassisted ammonia synthesis technology,analyzes existing dilemmas and challenges,and provides insights and recommendations for the future of nonthermal plasma ammonia processes.

关键词： plasma catalysis nitrogen fixation ammonia synthesis hydrogen storage catalyst carbon neutralization

Ag-doped CNT/HAP nanohybrids in a PLLA bone scaffold show significant antibacterial activity

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Bio-Design and Manufacturing 2024年第2期7卷 105-120页

作者： Cijun Shuai Xiaoxin Shi kai Wang Yulong Gu feng Yang Pei feng State Key Laboratory of Precision Manufacturing for Extreme Service Performance College of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China Institute of Additive Manufacturing Jiangxi University of Science and TechnologyNanchang 330013China College of Mechanical Engineering Xinjiang UniversityUrumqi 830017China

Bacterial infection is a major problem following bone implant ***,poly-l-lactic acid/carbon nanotube/hydroxyapatite(PLLA/CNT/HAP)bone scaffolds possess enhanced mechanical properties and show good ***,wesynthesizedsilver(Ag)-dopedCNT/HAP(CNT/Ag-HAP)nanohybrids via the partial replacing of calcium ions(Ca2+)in the HAP lattice with silver ions(Ag+)using an ion doping technique under hydrothermal ***ﬁcally,the doping process was induced using the special lattice structure of HAP and the abundant surface oxygenic functional groups of CNT,and involved the partial replacement of Ca2+in the HAP lattice by doped Ag+as well as the in situ synthesis of Ag-HAP nanoparticles on CNT in a hydrothermal *** result-ing CNT/Ag-HAP nanohybrids were then introduced into a PLLA matrix via laser-based powder bed fusion(PBF-LB)to fabricate PLLA/CNT/Ag-HAP scaffolds that showed sustained antibacterial *** then found that Ag+,which pos-sesses broad-spectrum antibacterial activity,endowed PLLA/CNT/Ag-HAP scaffolds with this activity,with an antibacterial effectiveness of 92.65%.This antibacterial effect is due to the powerful effect of Ag+against bacterial structure and genetic material,as well as the physical destruction of bacterial structures due to the sharp edge structure of *** addition,the scaffold possessed enhanced mechanical properties,showing tensile and compressive strengths of 8.49 MPa and 19.72 MPa,***,the scaffold also exhibited good bioactivity and cytocompatibility,including the ability to form apatite layers and to promote the adhesion and proliferation of human osteoblast-like cells(MG63 cells).

关键词： Ag-doped Carbon nanotube/hydroxyapatite(CNT/HAP) Antibacterial properties Bone scaffold

Covariate-Assisted Matrix Completion with Multiple Structural Breaks

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Journal of Systems Science & Complexity 2024年第2期37卷 692-728页

作者： MENG jing feng Long ZOU Changliang WANG Zhaojun School of Statistics and Data Science KLMDASRLEBPSand LPMCNankai UniversityTianjin 300071China

In matrix completion,additional covariates often provide valuable information for completing the unobserved entries of a high-dimensional low-rank matrix *** this paper,the authors consider the matrix recovery problem when there are multiple structural breaks in the coefficient matrix β under the column-space-decomposition model A=Xβ+B.A cumulative sum(CUSUM)statistic is constructed based on the penalized estimation of β.Then the CUSUM is incorporated into the Wild Binary Segmentation(WBS)algorithm to consistently estimate the location of ***,a nearly-optimal recovery of A is *** findings are further corroborated via numerical experiments and a real-data application.

关键词： Additional covariates matrix completion multiple structural breaks wild Binary Segmentation

Sound event localization and detection based on deep learning

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Journal of Systems Engineering and Electronics 2024年第2期35卷 294-301页

作者： ZHAO Dada DING kai QI Xiaogang CHEN Yu feng Hailin School of Mathematics and Statistics Xidian UniversityXi’an 710071China Science and Technology on Near-Surface Detection Laboratory Wuxi 214035China

Acoustic source localization(ASL)and sound event detection(SED)are two widely pursued independent research *** recent years,in order to achieve a more complete spatial and temporal representation of sound field,sound event localization and detection(SELD)has become a very active research *** paper presents a deep learning-based multioverlapping sound event localization and detection algorithm in three-dimensional ***-Mel spectrum and generalized cross-correlation spectrum are joined together in channel dimension as input *** features are classified and regressed in parallel after training by a neural network to obtain sound recognition and localization results *** channel attention mechanism is also introduced in the network to selectively enhance the features containing essential information and suppress the useless ***,a thourough comparison confirms the efficiency and effectiveness of the proposed SELD *** experiments show that the proposed algorithm is robust to reverberation and environment and can achieve higher recognition and localization accuracy compared with the baseline method.

关键词： sound event localization and detection(SELD) deep learning convolutional recursive neural network(CRNN) channel attention mechanism

A versatile model with three-dimensional triangular lattice for unconventional transport and various topological effects

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National Science Review 2024年第1期11卷 204-214页

作者： jing-Yang You Gang Su Yuan Ping feng Department of Physics National University of Singapore Kavli Institute for Theoretical Sciences and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Centre for Advanced 2D Materials National University of Singapore

The finite Berry curvature in topological materials can induce many subtle phenomena, such as the anomalous Hall effect(AHE), spin Hall effect(SHE), anomalous Nernst effect(ANE), non-linear Hall effect(NLHE) and bulk photovoltaic effects. To explore these novel physics as well as their connection and coupling, a precise and effective model should be developed. Here, we propose such a versatile model—a 3D triangular lattice with alternating hopping parameters, which can yield various topological phases,including kagome bands, triply degenerate fermions, double Weyl semimetals and so on. We reveal that this special lattice can present unconventional transport due to its unique topological surface states and the aforementioned topological phenomena, such as AHE, ANE, NLHE and the topological photocurrent effect. In addition, we also provide a number of material candidates that have been synthesized experimentally with this lattice, and discuss two materials, including a non-magnetic triangular system for SHE, NLHE and the shift current, and a ferromagnetic triangular lattice for AHE and ANE. Our work provides an excellent platform, including both the model and materials, for the study of Berry-curvature-related physics.

关键词： three-dimensional triangular lattice different topological phases various topological effects Berry curvature

Upcycling electroplating sludge into bioengineering-enabled highly stable dual-site Fe-Ni_(2)P@C electrocatalysts for efficient oxygen evolution

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Nano Research 2024年第8期17卷 6984-6992页

作者： Jiawen Liu Zunpeng Zuo feng Gao kai Yi Jiahui Lin Mengye Wang Zhang Lin feng Huang State Key Laboratory of Optoelectronic Materials and Technologies School of MaterialsSun Yat-Sen UniversityGuangzhou 510275China Department of Chemistry City University of Hong KongHong Kong 999077China School of Metallurgy and Environment Central South UniversityChangsha 410083China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China

The advancement of bimetallic catalysts holds significant promise for the innovation of oxygen evolution reaction(OER)*** from adsorbate evolution mechanism(AEM)and lattice oxygen oxidation mechanism(LOM),the incorporation of dual active sites has the potential to foster novel OER pathways,such as the coupled oxygen evolution mechanism(COM),which can surpass the limitations of OER and elevate catalytic *** this study,uniformly distributed Fe/Ni dual-site Fe-Ni_(2)P@C electrocatalysts are crafted by upcycling metals in electroplating sludge via an eco-friendly and sustainable microbial engineering *** findings indicate that a substantial number of defects emerge at the Ni2P crystal during the OER process,laying the groundwork for lattice oxygen ***,the displacement of Ni/Fe in the crystal lattice intensifies the asymmetry of the electronic structure at the metal active sites,facilitating the deprotonation *** research introduces an innovative paradigm for the synthesis of effective and robust transition metal-based OER catalysts,with implications for sustainable energy generation technologies.

关键词： oxygen evolution reaction dual active sites adsorbate evolution mechanism lattice oxygen mechanism bioengineering

Efflcient machining of a complex blisk channel using a disc cutter

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Chinese Journal of Aeronautics 2024年第1期37卷 414-437页

作者： Xiangyu LI Zhaoyu LI Dong HE Junxue REN Qian feng kai TANG Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong Kong 999077China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Xi’an Sanhang Power Technology Co. LtdXi’an 710000China HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute FutianShenzhen 518057China HKUST Shenzhen Research Institute Shenzhen 518057China

For rough machining of a complex narrow cavity,e.g.,a complex blisk channel on an aero-engine,the typically used cutting tools are the slender cylindrical cutter and conical ***,as neither of the two is particularly suited for rough machining,wherein the main purpose is to remove a large volume as quickly as possible,the machining efficiency is low,especially when the part materials are of hard-to-cut types(e.g.,Titanium-alloy)for which it often takes days to rough machine a ***,disc machining provides a new and efficient roughing solution,since a disc cutter with a large radius enables a much larger cutting speed and thus a larger material removal ***,due to the large radius of the disc cutter,its potential collision with narrow and twisted channels becomes a serious *** this paper,we propose a novel twophase approach for efficiently machining a complex narrow cavity workpiece using a disc-shaped cutter,i.e.,3+2-axis disc-slotting of the channel by multiple layers(rough machining)+five-axis disc-milling of the freeform channel side surfaces(semi-finish machining).Both simulation and physical cutting experiments are conducted to assess the effectiveness and advantages of the proposed *** experimental results show that,with respect to a same cusp-height threshold on the channel side surfaces,the total machining time of the tested part by the proposed method is about only 36%of that by the conventional approach of plunging-milling(for roughing)plus milling by a slender cylindrical cutter(for semi-finishing).

关键词： Blisk channel CNC machining Disc cutter Roughing efficiency Tool path planning