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PREPARATION OF mULTI-WALLED CARBON NANOTUBES USING NiO CATALyST SyNTHESIZED By HyDROTHERmAL mETHOD

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Acta metallurgica Sinica(English Letters) 2003年第5期16卷 416-420页

作者： y.J.Zhu y.L.chen X.m.Xue y.m.chen C.y.Wu T.C.Kuang S.H.Li H.y.Zhang DepartmentofAppliedPhysics GuangdongUniversityofTechnologyGuangzhou510090China CenterofAnalysisTesting GuangdongUniversityofTechnologyGuangzhou510O9OChina FacultyofmaterialandEnergy GuangdongUniversityofTechnologyGuangzhou510090.China

The Ni(OH)2/SiO2 binary colloid was prepared using Ni(NO3)2.6H2O and (C2H5O)4SiO4 as starting materials and was used to form NiO/SiO2. composite powder by hydrothermal method and desiccant method in open air respectively. multi-walled carbon nanotubes (mWCNTs) were synthesized respectively by chemical vapor deposition using the NiO/SiO2 catalyst prepared by different methods. The phase and morphology of the catalysts and the morphology, output yield and purity of mWCNTs were compared by XRD, TEm and SEm. The results show that the catalyst powder prepared by hydrothermal method, compared with that by desiccant method, is smaller, better dispersion and has stronger catalytic activity. Pure mWCNTs with smaller tube diameter and narrow range could be obtained at a high yield using that NiO/SiO2 powder prepared by hydrothermal method as catalyst.

关键词： hydrothermal method dry method at atmosphere carbon nan- otube catalytic pyrolysis

A CLASSICAL TRAJECTORy STUDy BASED ON mBE POTENTIAL ENERGy FUNCTIONS——REACTIVE COLLISIONS OF C+CH

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原子与分子物理学报 1990年第4期7卷 1693-1698页

作者： Z.H.Zhu y.m.chen H.G.yu Z.G.Xu Q.Q.Gou The Institute of Atomic and molecular Physics chengdu University of Science and Technology ChengduChina

Classical trajectories have been calculated for the reaction C+CH→C_(2)+H using many-body expansion(mBE)potential energy function of C_(2)*** present work gives the reactive cross sections at relative kinetic energy ... 详细信息

关键词： REACTIVE COLLISIONS OF C A CLASSICAL TRAJECTORy STUDy BASED ON mBE POTENTIAL ENERGy FUNCTIONS mBE CH

Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO_(2)thin films

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X chen m m chen y Liu D W Cao G J chen Department of microelectronics Jiangsu UniversityZhenjiang 212013China Department of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–Hong Kong–macao Joint Laboratory for Intelligent micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CmOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)

CORRELATION BETWEEN THE ELASTIC AND THE VIBRONIC BEHAVIOR OF NANOSTRUCTURED TITANIA AND THEIR PRESSURE,SIZE,AND TEmPERATURE DEPENDENCE

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Journal of Advanced Dielectrics 2011年第4期1卷 407-416页

作者： X.J.LIU L.K.PAN Z.SUN y.m.chen X.X.yANG L.W.yANG Z.F.ZHOU CHANG Q.SUN Engineering Research Center for Nanophotonics&Advanced Instrument ministry of Education Department of Physics East China Normal University Shanghai 200062P.R.China Institute for Quantum Engineering and micro-Nano Energy Technology Key Laboratory of Low-Dimensional materials and Application Technology and Faculty of materials and Optoelectronic Physics Xiangtan University Hunan 411105P.R.China School of Electrical and Electronic Engineering Nanyang Technological University Singapore 639798 Singapore

Correlation bet ween the elastic and the vibronic behavior of TiO_(2) and their responses to thevariation of crystal size,applied pressure,and measuring temperature has been investig ated basedon the bond order-length-strength correlation *** reproduction of themeasurements clarified that.(i)the elastic modulus(B)and the Raman shifts(△ω)are stronglycorrelated and we can know either one of the B or the △ω from the other;(i)the under-coordination induced cohesive energy loss and the energy density gain in the surface up to skindepth determines the size effect;(ii)bond expansion and bond weakening due to thermalvibration originat es the thermally softened elastic modulus and the Raman shifts;and(iv)bondcompression and bond strengthening results in the mechanically stiffened elastic modulus and theRaman *** the developed premise,one can predict the changing trends of the concernedproperties with derivatives of quantitative information of the atomic cohesive energy,bindingenergy density,Debye tempera ture,and nonlinear compressibility of the specimen.

关键词： TiO_(2)nanostructures elasticity Ramanshift pressure temperature

The technology for detection of gamma-ray burst with GECAm satellite

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Radiation Detection Technology and methods 2022年第1期6卷 12-25页

作者： X.Q.Li X.y.Wen Z.H.An C.Cai Z.Chang G.chen C.chen y.y.Du m.Gao R.Gao K.Gong D.y.Guo J.J.He D.J.Hou y.G.Li C.y.Li G.Li L.Li X.F.Li m.S.Li X.H.Liang X.J.Liu y.Q.Liu F.J.Lu H.Lu B.meng W.X.Peng F.Shi X.L.Sun H.Wang J.Z.Wang y.S.Wang H.Z.Wang X.Wen S.Xiao S.L.Xiong y.B.Xu y.P.Xu S.yang J.W.yang Q.B.yi D.L.Zhang Fan Zhang S.N.Zhang C.y.Zhang C.m.Zhang Fei Zhang X.y.Zhao y.Zhao X.Zhou C.S.Zhang J.P.yu L.Chang K.K.Zhang J.Huang y.m.chen X.B.Han Institute of High Energy Physics CASBeijing 100049China Xiangtan University Xiangtan 411105China Beijing Normal University Beijing 110875China Beijing Glass Research Institute Beijing 101100China Innovation Academy for microsatellites of CAS Shanghai 201204China

Introduction The main physical objective of the GECAm satellite is to detect gamma-ray bursts,which is related to gravitational waves of double compact object *** GECAm satellite also detects and investigates various bursts of high-energy celestial *** and methods In this study,we designed,developed and calibrated the payload and launched it into orbit with GECAm *** payload consists of the gamma ray detector(GRD,for detecting 4 keV–4 meV X/γray),the charged particle detector(CPD,for detecting 150 keV–5 meV charged particle),and the electronic box(EBOX).The all-sky field coverage is achieved via two 229-degree large-area satellites positioned 180 degrees apart and are on opposite sides of the *** satellite is equipped with 25 GRDs and 8 CPDs;thus,the satellite can identify charged particle bursts in ***-ray detectors adopt lanthanum bromide crystal technology combined with silicon *** is the first time that this technology was used massively in space *** The GECAm satellite can quickly determine the direction of gamma-ray bursts(positioning)via indexing and fitting method,while the transmit variability,energy spectrum and direction of the gamma-ray bursts guide subsequent observations through the Beidou-3 RDSS in quasi-real *** will play an important role in the study of high energy celestial bursts.

关键词： GECAm Gamma-ray burst Lanthanum bromide crystal Silicon photomultiplier Beidou short message

Cooperative Target Fencing of multiple Vehicles for a General Target with Connectivity Preservation and Collision Avoidance

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Journal of Systems Science & Complexity 2024年第1期37卷 136-151页

作者： PAN Zini chen Ben m Department of mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem for n-dimensional systems and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull formed by the ***,the dynamics of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the communication network and collision avoidance among the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a numerical example.

关键词： multi-agent systems networked systems target fencing

Generation of polarized electron beams through self-injection in the interaction of a laser with a pre-polarized plasma

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High Power Laser Science and Engineering 2024年第3期12卷 62-68页

作者： L.R.yin X.F.Li y.J.Gu N.Cao Q.Kong m.Büscher S.m.Weng m.chen Z.m.Sheng Key Laboratory of Nuclear Physics and Ion-beam Application(moE) Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan UniversityShanghaiChina State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina SANKEN(Institute of Scientific and Industrial Research) Osaka UniversityOsakaJapan Sichuan Research Institute Shanghai Jiao Tong UniversityChengduChina Peter Grünberg Institut(PGI-6) Forschungszentrum JülichJülichGermany Institut für Laser-und Plasmaphysik Heinrich-Heine-Universität DüsseldorfDüsseldorfGermany Key Laboratory for Laser Plasmas(moE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghaiChina Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghaiChina

Polarized electron beam production via laser wakefield acceleration in pre-polarized plasma is investigated by particlein-cell *** evolution of the electron beam polarization is studied based on the Thomas±Bargmann±michel±Telegdi equation for the transverse and longitudinal self-injection,and the depolarization process is found to be influenced by the injection *** the case of transverse self-injection,as found typically in the bubble regime,the spin precession of the accelerated electrons is mainly influenced by the ***,in the case of longitudinal injection in the quasi-1D regime(for example,*** et al.,***.110,135002(2013)),the direction of electron spin oscillates in the laser *** the electrons move around the laser axis,the net influence of the laser field is nearly zero and the contribution of the wakefield can be ***,an ultra-short electron beam with polarization of 99%can be obtained using longitudinal self-injection.

关键词： laser wakefield acceleration longitudinal self-injection particle-in-cell simulation polarized electron beam

A hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction

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Control Theory and Technology 2024年第3期22卷 394-405页

作者： Chuanxiang Gao Xinyi Wang Xi chen Ben m.chen Department of mechanical and Automation Engineering The Chinese University of Hong KongHong KongShatinNTChina

Unmanned aerial vehicles(UAVs)are emerging as a powerful tool for inspections and repair works in large-scale and unstructured 3D infrastructures,but current approaches take a long time to cover the entire *** using UAVs for inspections and repair works puts forward a requirement of improving time efficiency in large-scale and cluster *** paper presents a hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction to balance the workload and reduce the overall task completion *** proposed framework consists of two stages,the exploration stage and the exploitation stage,resolving the task in a sequential *** the exploration stage,the density map is developed to update global and local information for dynamic load-balanced area partition based on reconstructability and relative positions of UAVs,and the Voronoi-based planner is used to enable the UAVs to reach their best *** obtaining the global map,viewpoints are generated and divided while taking into account the battery capacity of each ***,a shortest path planning method is used to minimize the total traveling cost of these viewpoints for obtaining a high-quality *** experiments are conducted in both a simulated and real environment to show the time efficiency,robustness,and effectiveness of the proposed ***,the whole system is implemented in real applications.

关键词： multi-UAV Coverage path planning Infrastructure inspection and reconstruction

Physics-informed deep learning for fringe pattern analysis

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Opto-Electronic Advances 2024年第1期7卷 4-15页

作者： Wei yin yuxuan Che Xinsheng Li mingyu Li yan Hu Shijie Feng Edmund y.Lam Qian chen Chao Zuo Smart Computational Imaging Laboratory(SCILab) School of Electronic and Optical EngineeringNanjing University of Science and TechnologyNanjing 210094China Smart Computational Imaging Research Institute(SCIRI)of Nanjing University of Science and Technology Nanjing 210019China Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense Nanjing 210094China Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong Kong SAR 999077China

Recently,deep learning has yielded transformative success across optics and photonics,especially in optical *** neural networks (DNNs) with a fully convolutional architecture (e.g.,U-Net and its derivatives) have been widely implemented in an end-to-end manner to accomplish various optical metrology tasks,such as fringe denoising,phase unwrapping,and fringe ***,the task of training a DNN to accurately identify an image-to-image transform from massive input and output data pairs seems at best naive,as the physical laws governing the image formation or other domain expertise pertaining to the measurement have not yet been fully exploited in current deep learning *** this end,we introduce a physics-informed deep learning method for fringe pattern analysis (PI-FPA) to overcome this limit by integrating a lightweight DNN with a learning-enhanced Fourier transform profilometry (Le FTP) *** parameterizing conventional phase retrieval methods,the Le FTP module embeds the prior knowledge in the network structure and the loss function to directly provide reliable phase results for new types of samples,while circumventing the requirement of collecting a large amount of high-quality data in supervised learning *** by the initial phase from Le FTP,the phase recovery ability of the lightweight DNN is enhanced to further improve the phase accuracy at a low computational cost compared with existing end-to-end *** results demonstrate that PI-FPA enables more accurate and computationally efficient single-shot phase retrieval,exhibiting its excellent generalization to various unseen objects during *** proposed PI-FPA presents that challenging issues in optical metrology can be potentially overcome through the synergy of physics-priors-based traditional tools and data-driven learning approaches,opening new avenues to achieve fast and accurate single-shot 3D imaging.

关键词： optical metrology deep learning physics-informed neural networks fringe analysis phase retrieval