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Nuclear Science and Techniques 2019年第7期30卷 36-41页

作者： Jia-Qi Chen Qiu-Shi Huang Run-Ze Qi Yu-Fei Feng Jiang-Tao Feng Zhong Zhang Wen-Bin Li Zhan-Shan Wang MOE Key Laboratory of Advanced micro-Structured Materials Institute of Precision Optical Engineering (IPOE)School of Physics Science and Engineering Tongji University

Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics. In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high-reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers (15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction, and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au (111) orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200℃ in a vacuum was performed on the films deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the films. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 ℃ and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175℃, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.

关键词： Gold films Sputtering power Annealing microstructure Roughness

Optical manipulation in optofluidic microbubble resonators

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Science China(Physics,Mechanics & Astronomy) 2015年第11期58卷 34-39页

作者： WANG HaoTian WU Xiang Shanghai Ultra-Precision Optical Manufacturing engineering Research Center Key Lab for Micro and Nanophotonic Structures (Ministry of Education) and Department of Optical Science and Engineering Fudan University

An optical manipulation system based on optofiuidic microbubble resonators （MBR） is proposed. As the high-Q whispering gallery modes （WGMs） are excited in an MBR, the buildup of the field intensity inside the resonator is large enough to trap nanoscale particles. The optical gradient forces generated by the WGMs with different radial orders are investigated numeri- cally. The negative effect of the resonance detuning induced by the particles is taken into account to investigate the optical gradient forces exerting on the particles. By the stability analysis, the WGMs with high radial orders show a better trapping stability under Brownian motion since most of the optical fields reside within the water core.

关键词： optical trapping whispering gallery mode ring resonator resonance detuning

Paving the Way to Smart micro Energy Grid:Concepts,Design Principles,and engineering Practices

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CSEE Journal of Power and Energy Systems 2017年第4期3卷 440-449页

作者： Shengwei Mei Rui Li Xiaodai Xue Ying Chen Qiang Lu Xiaotao Chen Carsten D.Ahrens Ruomei Li Laijun Chen State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Key Laboratory of Clean Energy School of QiDi(TUS)Renewable EnergyQinghai UniversityXining 810016China Faculty of Civil engineering and Geoinformation(BGG) University of Applied SciencesOldenburg D-26203Germany China Electric Power Research Institute Beijing 100192China

The interconnection between initially independent energy infrastructures offers additional system flexibility and *** integration at distribution level simplifies the implementation of the integrated energy system *** paper proposes concepts and design principles of a smart micro energy grid(MEG)for accommodating micro-grids,distributed poly-generation systems,energy storage facilities,and associated energy distribution *** energy management system is responsible for the smart operation of the MEG while supporting multiple criteria,such as safety,economy,and environmental *** realize the vision of the smart MEG,an engineering game theory based energy management system with self-approaching-optimum capability is *** on the proposed concepts,design principles,and energy management system,this paper presents a prototype of China’s first conceptual solar-based smart MEG,established in Qinghai University.

关键词： Energy management engineering game theory self-approaching-optimum smart micro energy grid solar-based conceptual prototype

microstructure of nanometer Al_2O_3 dispersion strengthened Ni-based high-temperature protective coatings by laser cladding

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中国有色金属学会会刊：英文版 2009年第3期19卷 586-591页

作者：王宏宇左敦稳孙玉利徐锋张丹 Jiangsu Key Laboratory of Precision and micro-manufacturing Technology Nanjing University of Aeronautics and Astronautics School of Mechanical engineering Jiangsu University

The nanometer Al2O3 dispersion strengthened NiCoCrAlY high-temperature protective coatings by crosscurrent CO2 laser on Ni-based superalloy GH4033 were produced. microscopic morphologies, phase constitutions of cladding coatings and distribution of nano-Al2O3 particles were examined using SEM and XRD. The results show that the interface grains, after adding proper nano-Al2O3, grow from epitaxial to non-epitaxial shape gradually, and the columnar dendrites become thinner and denser with cellular shape. Cracks in the substrate close to the interface are eliminated. Moreover, dispersive nano-Al2O3 particles mainly distribute around cellular substructure and on grain-boundaries, which prevents the diffusion of alloying elements and restrains the formation of new phase. There is a critical value of nano-Al2O3 addition, and the most suitable content of nano-Al2O3 is 1% (mass fraction) in this experimental conditions. The "nanometer effect" of nano-Al2O3 particles plays an important role in the improvement of coating microstructure.

关键词：纳米Al2O3 NiCoCrAlY 高温防护涂层弥散强化激光熔覆微观结构 Al2O3微粒 Al2O3颗粒

Low-energy(40 keV) proton irradiation of YBa_2Cu_3O_(7-x) thin films:micro-Raman characterization and electrical transport properties

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Chinese Physics B 2019年第2期28卷 406-413页

作者： San-Sheng Wang Fang Li Han Wu Yu Zhang Suleman Muhammad Peng Zhao Xiao-Yun Le Zhi-Song Xiao Li-Xiang Jiang Xue-Dong Ou Xiao-Ping Ouyang Key Laboratory of micro-nano Measurement Manipulation and PhysicsMinistry of EducationBeihang University Beijing Institute of Spacecraft engineering Environment

To investigate the damage profiles of high-fluence low-energy proton irradiation on superconducting materials and related devices, Raman characterization and electrical transport measurement of 40-keV-proton irradiated YBa_2Cu_3O_(7-x)(YBCO) thin films are carried out. From micro-Raman spectroscopy and x-ray diffraction studies, the main component of proton-radiation-induced defects is found to be the partial transition of superconducting orthorhombic phase to the semiconducting tetragonal phase and non-superconducting secondary phase. The results indicate that the defects induced in the conducting CuO_2 planes, such as increased oxygen vacancies and interstitials, can result in an increase in the resistivity but a decrease in the transition temperature TCwith the increase in the fluence of proton irradiation, which is confirmed in the electrical transport measurements. Especially, zero-resistance temperature TC_0 is not observed at a fluence of 10^(15)p/cm^***, the variation of activation energy U_0 can be explained by the plastic-flux creep theory, which indicates that the plastic deformation and entanglement of vortices in a weakly pinned vortex liquid are caused by disorders of point-like defects. Point-like disorders are demonstrated to be the main contribution to the low-energy proton radiation damage in YBCO thin films. These disorders are likely to cause flux creep by thermally assisted flux flow, which may increase noise and reduce the precision of superconducting devices.

关键词： superconductors proton radiation micro-Raman spectra electrical transport

Glass capillary nanopore for single molecule detection

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Science China(Technological Sciences) 2015年第5期58卷 803-812页

作者： SHA JingJie SI Wei XU Wei ZOU YiRen CHEN YunFei Jiangsu Key Laboratory for Design and Manufacture of micro-Nano Biomedical Instruments Southeast University School of Mechanical engineering Southeast University

Single molecule detection based on nanopore technology is a very promising approach for medical diagnostics, drug therapy and even DNA sequencing. Compared with other biological nanopores and solid-state nanopores, the glass capillary nanopore has low cost, easy availability and stable mechanical characteristics, thus it has been widely used in the nanopore technology for single molecule detection. In this review, we will focus on the studies of the glass nanopore sensors. The popular glass nanopore fabrication methods would be introduced, and the applications of glass nanopores in the detection of nanoparticles, proteins and DNA molecules would be presented. We hope this review will help widen field of vision and promote the development of the nanopore technology based on the glass capillary nanopores.

关键词： fabrication capillary nanotubes sequencing diameters SWNTs DNA etching diagnostics nanometer

Topological laser on square lattice with gain–loss-induced higher-order corner modes

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Chinese Physics B 2024年第6期33卷 189-195页

作者：廖明杰韦梅松王帅领许静平羊亚平 MOE Key Laboratory of Advanced micro-Structured Materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China

We investigate the higher-order topological laser in the two-dimensional(2D) coupled-cavity array. By adding staggered on-site gain and loss to the 2D Hermitian array with a trivial phase, the system will emerge degenerate topological corner modes, which are protected by bulk band gap. For such a non-Hermitian model, by adjusting the parameters of the system and introducing the pumping into the cavity at the corner, a single-mode lasing with topological protection ***, single-mode lasing exists over a wide range of pumping strengths. No matter where the cavity is initially stimulated, after enough time evolution, all the cavities belonging to the topological corner mode can emit a stable laser.

关键词： topological corner modes nonlinear saturated gain single-mode lasing

Near-perfect replication on amorphous alloys through active force modulation based on machine learning/neural network parameter prediction

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 181-191页

作者： Senkuan Meng Zheng Wang Ruisong Zhu Ruijie Liu Jiang Ma Lina Hu Weihua Wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shandong University College of Mechatronics and Control engineering Shenzhen University Songshan Lake Materials Laboratory Institute of Physics Chinese Academy of Sciences

As a microforming technique, micro/nano-structural replication possesses advantages of high precision and efficiency. With the remarkable superplasticity in the supercooled liquid region, amorphous alloys or metallic glasses(MGs) are regarded as ideal materials for miniature fabrication. However, due to the intrinsic metastable nature of supercooled liquids, the design of imprinting processes for MGs poses a challenge. In the past, process parameters have largely relied on trial-and-error *** this work, a low-frequency active force modulation system is employed to apply a stable, precise, and real-time feedback stress field for imprinting of MG samples. Low-frequency vibrations can facilitate the filling of microstructures on the template surface by reducing the effective viscosity of the supercooled liquid. With the dataset composed of orthogonal experiments, a machine learning strategy based on back-propagation(BP) neural networks was utilized to construct a 3D parameter space for temperature, stress, and time, and to predict the corresponding filling ratio. Furthermore, the optimal combination of imprinting process parameters was identified, and its filling ratio was experimentally validated to reach as high as 0.94. The near-perfect replication of microstructures confirms the superiority of the active force modulation system and the data-driven strategy of machine learning-assisted parameter design. At the same time, this one-step microforming process provides a new approach to addressing the accuracy-cost trade-off dilemma in precision manufacturing.

关键词： metallic glass amorphous alloy microforming imprinting machine learning

System level simulation of a micro resonant accelerometer with geometric nonlinear beams

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Journal of Semiconductors 2015年第10期36卷 80-85页

作者：焦文龙苑伟政常洪龙 School of Mechanical engineering Northwestern Polytechnical University Key Laboratory of micro/Nano Systems for Aerospace Ministry of Education

Geometric nonlinear behaviors ofmicro resonators have attracted extensive attention of MEMS （micro- electro-mechanical systems） researchers, and MEMS transducers utilizing these behaviors have been widely re- searched and used due to the advantages of essentially digital output. Currently, the design of transducers with nonlinear behaviors is mainly performed by numerical method and rarely by system level design method. In this paper, the geometric nonlinear beam structure was modeled and established as a reusable library component by sys- tem level modeling and simulation method MuPEN （multi port element network）. A resonant accelerometer was constructed and simulated using this model together with MuPEN reusable library. The AC （alternating current） analysis results of MuPEN model agreed well with the results of architect model and the experiment results shown in the existing reference. Therefore, we are convinced that the beam component based on MuPEN method is valid, and MEMS system level design method and related libraries can effectively model and simulate transducers with geometric nonlinear behaviors if appropriate system level components are available.

关键词： micro-electro-mechanical systems system level simulation micro resonant accelerometer nonlinearbeam resonator

Ion specificity in NaCl solution confined in silicon nanochannels

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Science China(Technological Sciences) 2014年第1期57卷 230-238页

作者： QIU YingHua TAN QiYan SI Wei CHEN YunFei School of Mechanical engineering and Jiangsu Key Laboratory for Design and Manufacture of micro-Nano Biomedical Instruments Southeast University

Ion specificity of Na＋ and C1- ions for NaCI solution confined in silicon nanochannels is investigated with molecular dynamics （MD） simulations. The MD simulation results demonstrate that ion specificity for Na＋ and C1- ions exhibits clearly in na- nochannels with high surface charge density. The two types of ions show different density distributions perpendicular to the channel surface due to the ion specificity when they act as countefions near negatively and positively charged surfaces, respec- tively. Both the two counterion distributions cannot be predicted by Poisson-Boltzmann equation within 0.75 nm near the sur- face. In addition, the ion specificity is also demonstrated through affecting the water density distributions. In the nanochannel with negatively charged surfaces, the presence of the Na＋ ions reduces the number of water peaks in water density distribution profile. In comparison, when the C1- ions act as counterions near positively charged surfaces, they do not affect the number of the water peaks. Besides the influence on the water density distribution, ion specificity also exhibits through affecting the wa- ter molecule orientation in the adsorbed layer. It is found that C1- ions make the water molecules in the adsorbed layer align more orderly than Na~ ions do when the two types of ions act as the counterions near the positively and negatively charged surfaces with the same surface charge density.

关键词： ion specificity molecular dynamics simulations nanochannel Poisson-Boltzmann equation electrical double layer