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COMPARISON OF SURFACE PROPERTIES OF Ti-6Al-4V COATED WITH TITANIUM NITRIDE, TiN+TiC+Ti(C,N)/DLC, TiN/DLC AND TiC/DLC FILMS BY PLASma-BASED ION IMPLANTATION

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Acta Metallurgica Sinica(English Letters) 2000年第4期13卷 967-973页

作者： Ji, H.B. xia, L.F. ma, x.x. Sun, Y. Sun, M.R. Harbin Inst of Technology Harbin China

The surface properties of Ti-6Al-4V alloy coated with titanium nitride, TiN+TiC+Ti(C,N)/DLC (diamond like carbon), TiN/DLC and TiC/DLC films by plasma-based ion implantation (PBII) with nitrogen, PBII with nitrogen then acetylene, PBII with nitrogen then glow discharge deposition with acetylene plus hydrogen and PBII with acetylene then glow discharge deposition with acetylene plus hydrogen respectively were studied. The corresponding films are found getting dimmer, showing light gold or gold, smoky color (uneven), light red in black (uneven), and graphite black separately. The corresponding film resistivities are given. Antioxidation ability of the titanium nitride film is poor, while the existence of carbon (or carbide) improves the antioxidation ability of the films. Having undergone excellent intermediate transitional region of nitrogen and carbon implantation, the top DLC layer of the TiN+TiC+Ti(C,N)/DLC multilayer are formed after the carbon implantation has the best adhesion with the substrate among all the multilayers. Although microhardness of the samples increases in the order of coatings of titanium nitride, TiN/DLC, TiN+TiC+Ti(C,N)/DLC and TiC/DLC, the TiN/DLC and TiC/DLC multilayers have greater brittleness as compared with other films.

关键词： Titanium alloys Titanium nitride Plasmas Ion implantation Microhardness Surface properties

In situ TEM investigation of electron irradiation and aging-induced high-density nanoprecipitates in an Mg-10Gd-3Y-1Zn-0.5Zr alloy

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Journal of magnesium and Alloys 2024年第5期12卷 1841-1853页

作者： M.Lv H.L.Ge Q.Q.Jin x.H.Shao Y.T.Zhou B.Zhang x.L.ma Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China materials Science and Engineering Research Center Guangxi University of Science and TechnologyLiuzhou 545006China

In-situ electron irradiation and aging are applied to introduce high-density precipitates in an Mg-10Gd-3Y-1Zn-0.5Zr(GWZ1031K,wt.%)alloy to improve the *** results show that the hardness of the Mg alloy after irradiation for 10 h and aging for 9 h at 250℃ is 1.64 GPa,which is approximately 64% higher than that of the samples before being *** is mainly attributed to γ'precipitates on the basal plane after irradiation and the high-density nanoscale β'precipitates on the prismatic plane after aging,which should be closely related to the irradiation-induced homogenous *** latter plays a key role in precipitation *** result paves a way to improve the mechanical properties of metallic materials by tailoring the precipitation through irradiation and aging.

关键词： Mg alloy Electron beam irradiation Hardening Precipitates In-situ TEM

Distinct Electrical and Mechanical Responses of a Cu-10Fe Composite Prepared by Hot-Pressed Sintering and Post Treatment

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 255-265页

作者： x.Y.Yue S.Y.Peng x.Zhang C.N.He Y.Z.Tian Key Laboratory for Anisotropy and Texture of materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China School of materials Science and Engineering and Tianjin Key Laboratory of Composite and Functional materials Tianjin UniversityTianjin300350China Research Centre for Metallic Wires Northeastern UniversityShenyang110819China

A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution *** hot-pressed sintered and solution treated materials were rolled and *** precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron *** contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe *** Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACS and softening temperature of 838 *** for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were *** findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.

关键词： Cu-Fe composite Hot-pressed sintering Thermal stability Strength Electrical conductivity

Fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

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matter and Radiation at Extremes 2024年第3期9卷 11-18页

作者： Y.x.Wang x.L.Zhu S.M.Weng P.Li x.F.Li H.Ai H.R.Pan Z.M.Sheng Key Laboratory for Laser Plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghai 200240China Research Center of Laser Fusion of China Academy of Engineering Physics MianyangSichuan 621900China State key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-IR)to terahertz(THz)range is of interest for applications in a number of fields,from fundamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-IR or THz ***,we present a photon deceleration scheme for the efficient generation of ultrashort mid-IR or THz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake ***,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer *** greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength IR and THz spectral ranges.

关键词： laser ultrashort photon

Ka-band thin film lithium niobate photonic integrated optoelectronic oscillator

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Photonics Research 2024年第6期12卷 1283-1293页

作者： RUI ma ZIJUN HUANG SHENGQIAN GAO JINGYI WANG xICHEN WANG xIAN ZHANG PENG HAO x.STEVE YAO xINLUN CAI State Key Laboratory of Optoelectronic materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510275China Photonics Information Innovation Center and Hebei Provincial Center for Optical Sensing College of Physics Science and TechnologyHebei UniversityBaoding 071002China NuVison Photonics Inc.Las VegasNevada 89109USA

Photonics integration of an optoelectronic oscillator(OEO)on a chip is attractive for fabricating low cost,compact,low power consumption,and highly reliable microwave sources,which has been demonstrated recently in silicon on insulator(SOI)and indium phosphide(InP)platforms at x-band around 8 *** we demonstrate the first integration of OEOs on the thin film lithium niobate(TFLN)platform,which has the advantages of lower Vπ,no chirp,wider frequency range,and less sensitivity to *** have successfully realized two different OEOs operating at Ka-band,with phase noises even lower than those of the x-band OEOs on SOI and InP *** is a fixed frequency OEO at 30 GHz realized by integrating a mach–Zehnder modulator(MZM)with an add-drop microring resonator(MRR),and the other is a tunable frequency OEO at 20–35 GHz realized by integrating a phase modulator(PM)with a notch *** work marks the first step of using TFLN to fabricate integrated OEOs with high frequency,small size,low cost,wide range tunability,and potentially low phase noise.

关键词： optoelectronic modulator resonator

Large non-pedunculated colorectal polyp management: The elephant in the room

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World Journal of Gastroenterology 2024年第25期30卷 3126-3131页

作者： Shirley x Jiang Neal Shahidi Department of Medicine University of British ColumbiaVancouver V6Z 2K5BCCanada

Minimally invasive innovations have transformed *** to colorectal cancer(CRC),there has been a shift towards less invasive surgical techniques and use of endoscopic resection as an alternative for low risk T1 *** role of endoscopic resection is however much more extensive:It is now considered the first line management strategy for most large(≥20 mm)non-pedunculated colorectal polyps,the majority of which are *** is due to the well-established efficacy,safety,and cost-effectiveness of endoscopic techniques compared to *** endoscopic modalities now exist with distinct risk-benefit profiles and their outcomes are further improved by site-specific technical modifications,auxiliary techniques,and adverse event miti-gation *** capacity continues to evolve with emerging endoscopic techniques and expanding applications,particularly in the confines of a multi-disciplinary setting.

关键词： Cancer Colonoscopy Endoscopy Polyp Endoscopic mucosal resection Endoscopic submucosal dissection

An adaptive machine learning-based optimization method in the aerodynamic analysis of a finite wing under various cruise conditions

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Theoretical & Applied Mechanics Letters 2024年第1期14卷 27-34页

作者： Zilan Zhang Yu Ao Shaofan Li Grace x.Gu Department of Mechanical Engineering University of CaliforniaBerkeley 94720USA Department of Engineering Peking UniversityBeijing 100871China Department of Civil and Environmental Engineering University of CaliforniaBerkeley 94720USA

Conventional wing aerodynamic optimization processes can be time-consuming and imprecise due to the complexity of versatile flight *** of existing literature has considered two-dimensional infinite airfoil optimization,while three-dimensional finite wing optimizations are subject to limited study because of high computational *** we create an adaptive optimization methodology built upon digitized wing shape deformation and deep learning algorithms,which enable the rapid formulation of finite wing designs for specific aerodynamic performance demands under different cruise *** methodology unfolds in three stages:radial basis function interpolated wing generation,collection of inputs from computational fluid dynamics simulations,and deep neural network that constructs the surrogate model for the optimal wing *** has been demonstrated that the proposed methodology can significantly reduce the computational cost of numerical *** also has the potential to optimize various aerial vehicles undergoing different mission environments,loading conditions,and safety requirements.

关键词： Aerodynamic optimization Computational fluid dynamics Radial basis function Finite wing Deep learning neural network

The preface: Interplay of topological and magnetic orders in the Mn-Bi-Te family

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National Science Review 2024年第2期11卷 6-7页

作者： Fu-Chun Zhang Hai-Zhou Lu x.C.xie Kavli Institute for Theoretical Sciences University of Chinese Academy of Sciences Department of Physics Southern University of Science and Technology (SUSTech) International Center for Quantum materials School of Physics Peking University

The discovery and synthesis of MnBi2Te4in 2013 initially garnered little attention [1]. Yet, the revelation of its topological properties in 2019 [2–6] sparked a surge of research into the MnBiTe family. These extensive studies are primarily driven by two objectives:the realization of a high-temperature quantum anomalous Hall effect （QAHE） and the exploration of exotic phases born from the interplay of topological and magnetic orders,

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Forecasting measured responses of structures using temporal deep learning and dual attention

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 832-850页

作者： Viet-Hung DANG Trong-Phu NGUYEN Thi-Lien PHAM Huan x.NGUYEN Department of Structural Mechanics Hanoi University of Civil EngineeringHanoi 11600Vietnam Faculty of Applied Science University of Economics-Technology for IndustriesHanoi 11600Vietnam London Digital Twin Research Centre Faculty of Science and TechnologyMiddlesex UniversityLondon NW44BTUK International School Vietnam National UniversityHanoi 11600Vietnam

The objective of this study is to develop a novel and efficient model for forecasting the nonlinear behavior of structures in response to time-varying random *** key idea is to design a deep learning architecture to leverage the relationships,between external excitations and structure's vibration signals,and between historical values and future values,within multiple time-series *** proposed method consists of two main steps:the first step applies a global attention mechanism to combine multiple-measured time series and time-varying excitation into a weighted time series before feeding it to a temporal architecture;the second step utilizes a self-attention mechanism followed by a fully connected layer to predict multi-step future *** viability of the proposed method is demonstrated via two case studies involving synthetic data from a three-dimensional(3D)reinforced concrete structure and experimental data from an 18-story steel ***,comparison and robustness studies are carried out,showing that the proposed method outperforms conventional methods and maintains high performance in the presence of noise with an amplitude of less than 10%.

关键词： structural dynamic time-varying excitation deep learning signal processing response forecasting