检索结果-南通市图书馆

Electro-optic lithium niobate metasurfaces

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2021年第4期64卷 28-33页

作者： BoFeng Gao MengXin Ren Wei Wu Wei Cai jingjun xu The Key Laboratory of Weak-Light Nonlinear Photonics Ministry of EducationSchool of Physics and TEDA Applied Physics InstituteNankai UniversityTianjin 300071China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Many applications of metasurfaces require an ability to dynamically change their properties in the time domain. Electrical tuning techniques are of particular interest, since they pave a way to on-chip integration of metasurfaces with optoelectronic *** this work, we propose and experimentally demonstrate an electro-optic lithium niobate(EO-LN) metasurface that shows dynamic modulations to phase retardation of transmitted light. Quasi-bound states in the continuum(QBIC) are observed from this metasurface. By applying external electric voltages, the refractive index of lithium niobate(LN) is changed by Pockels EO nonlinearity, leading to efficient phase modulations to the transmitted light around the QBIC wavelength. The EO-LN metasurface developed in this study opens up new routes for potential applications in the field of displaying, pulse shaping, and spatial light modulating.

关键词： lithium niobate metasurfaces electro-optic modulation bound states in the continuum resonance

Machine learning powered ellipsometry

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2021年第4期10卷 582-588页

作者： Jinchao Liu Di Zhang Dianqiang Yu Mengxin Ren jingjun xu The Key Laboratory of Weak-Light Nonlinear Photonics Ministry of EducationSchool of Physics and TEDA Applied Physics InstituteNankai UniversityTianjin 300071China College of Artificial Intelligence Nankai UniversityTianjin 300071China Collabo rative Innovation Center of Extreme Optics Shanxi UniversityTaiyuanShanxi 030006China

Ellipsometry is a powerful method for determining both the optical constants and thickness of thin *** decades,solutions to ill-posed inverse ellipsometric problems require substantial human-expert intervention and have become essentially human-in-the-loop trial-and-error processes that are not only tedious and time-consuming but also limit the applicability of ***,we demonstrate a machine learning based approach for solving ellipsometric problems in an unambiguous and fully automatic manner while showing superior *** proposed approach is experimentally validated by using a broad range of films covering categories of metals,semiconductors,and *** method is compatible with existing ellipsometers and paves the way for realizing the automatic,rapid,high-throughput optical characterization of films.

关键词： consuming inverse essentially

Deposition of Phase-pure Cr2AlC Coating by DC Magnetron Sputtering and Post Annealing Using Cr-Al-C Targets with Controlled Elemental Composition but Different Phase Compositions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2018年第3期34卷 466-471页

作者： Yueming Li Guorui Zhao Yuhai Qian jingjun xu Meishuan Li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100039China

Polycrystalline Cr2AlC coatings were prepared on M38G superalloy using a two-step method consisting of magnetron sputtering from Cr-Al-C composite targets at room temperature and subsequent annealing at 620 ℃. Particularly, various targets synthesized by hot pressing mixture of Cr, Al, and C powders at 650-1000 ℃ were used. It was found that regardless of the phase compositions and density of the com- posite targets, when the molar ratio of Cr：Al：C in the starting materials was 2：1：1, phase-pure crystalline Cr2AlC coatings were prepared by magnetron sputtering and post crystallization. The Cr2AIC coatings were dense and crack-free and had a duplex structure. The adhesion strength of the coating deposited on M38G superalloy from the 800 ℃ hot-pressed target and then annealed at 620 ℃ for 20 h in Ar exceeded 82 ± 6 MPa, while its hardness was 12 ± 3 GPa.

关键词： Cr2AlC Coating Magnetron sputtering Composite target Heat treatment

Effects of High Temperature Oxidation on Mechanical Properties of Ti_3AlC_2

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2017年第6期33卷 596-602页

作者： Xichao Li Lili Zheng Yuhai Qian jingjun xu Meishuan Li Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences University of Chinese Academy of Sciences

The oxidation tests of Ti_3AlC_2 were conducted at 1100 and 1200？C in air for 48 and 360 h, respectively,and the effects of high temperature oxidation on the flexural strength and hardness of Ti_3AlC_2 were investigated. The microstructure, grain size and phase compositions of Ti_3AlC_2 substrate didn＇t change after oxidation, hence the oxide removed Ti_3AlC_2 substrate maintained its initial flexural strength and hardness. However, the flexural strength of oxide retained Ti_3AlC_2 decreased by about 5%. Acoustic emission monitoring indicated that during the process of three-point bending test, the formed Al_2O_3 scale on Ti_3AlC_2 surface fractured firstly in a cleavage manner, then the substrate/oxide interface cracked,and finally the Ti_3AlC_2 substrate fractured. The mechanical degradation was caused by the preferential formation of cracks in brittle Al_2O_3 scale as well as at defective and lacunose grain boundaries of the substrate where stress concentration generated. The mechanical degradation was insensitive to oxidation temperature and time in the present conditions. In addition, the surface hardness increased significantly after oxidation due to the formed hard Al_2O_3 scale on the surface of Ti_3AlC_2 substrate.

关键词： Ti3AlC2 Oxidation Flexural strength Hardness Bending test Acoustic emission

Structural and functional studies of erythrocyte membrane-skeleton by single-cell and single-molecule techniques

在线全文

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2019年第1期12卷 1-13页

作者： Fulin Xing Fen Hu Jianyu Yang Leiting Pan jingjun xu The Key Laboratory of Weak-Light Nonlinear Photonics Ministry of Education School of Physics and TEDA Institute of Applied Physics Nankai University Tianjin 300071P.R.China Collaborative Innovation Center of Extreme Optics Shanxi University TaiyuanShanxi 030006P.R.China

As the indispensable oxygen-transporting cells,erythrocytes exhibit extreme deformability and amazing stability as they are subject to huge reversible shear stress and extrusion force during massive circulation in the *** unique architecture of spectrin-actin-based membraneskeleton is considered to be responsible for such excellent mechanical properties of *** erythrocytes have been recognized for more than 300 years,myriad questions about membrane-skeleton constantly attract people's ***,we summarize the kinds of distinctive single-cell and single-molecule techniques that were used to investigate the structure and function of erythrocyte membrane-skeleton at macro and micro levels.

关键词： Red blood cells membrane-skeleton optical tweezers micro°uidics super-resolution microscopy

Oxidation Behaviors of C-ZrB_2-SiC Composite at 2100℃ in Air and O_2

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2014年第12期30卷 1223-1229页

作者： Zhongwei Zhang Cewen Nan jingjun xu Zenghua Gao Meishuan Li Junshan Wang State Key Laboratory of New Ceramics & Fine Processing Department of Materials Science and Engineering Tsinghua University Science and Technology on Advanced Functional Composites Laboratory Aerospace Research Institute of Materials and Processing Technology Institute of Metal Research Chinese Academy of Sciences

The oxidation behaviors of graphite and ZrB2-SiC modified graphite composite were investigated at 2100℃ in1X105 Pa air and 0.2X105 Pa O2. The oxidation tests were conducted in an induction heating furnace. The oxidation of these two materials followed the linear rate law. The determined radius loss rates of graphite and C-ZrB2-Si C at 2100℃ were 2.18X10-2and 1.05X10-2%/s in 1X105 Pa air, and 3.23X10 2 and 2.21X10 2%/s in 0.2X105 Pa O2, respectively. The incorporation of ZrB2 and SiC decreased remarkably the oxidation rate of graphite because the oxide scale formed on the sample surface during oxidation helps in reducing the exposed surface area of the underneath substrate. In two different atmospheres with the same oxygen partial pressure, both graphite and ZrB2-SiC experienced more severe oxidation at 2100℃ in0.2X105 Pa O2than in 1X105 Pa air. The oxidation rate-controlling step for graphite and ZrB2-SiC was proposed to be the inward diffusion of oxygen through the boundary layer and through the pores in the oxide scale, respectively. A model based on diffusion theory was established to discuss the effect of the total gas pressure on their oxidation behaviors.

关键词： Graphite-based composite Ceramic particles Ultra-high temperature oxidation Oxide scale Oxidation mechanism

Restoration and Amplification of Images Through Randomly-Moving Suspension Particles Using Photorefractive Two-Wave Mixing

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1994年第2期11卷 91-94页

作者： ZHANG Guangyin xu jingjun LIU Simin MEN Liqiu LIU Junxnin Department of Physics Nankai UniversityTianjin 300071

Weak images,which pass through two kinds of suspension media with sizes of randomly-moving suspension particles about 0.05-0.1 cm and 0.01-0.001 cm respectively,are deteriorated by light scattering of particles,but re... 详细信息

关键词： mixing sizes Image

Li^(+)doping induced zero-thermal quenching in Cs_(3)Zn_(6-x-y)B_(9)O_(21):xEu^(3+),yLi^(+)(0≤x≤0.10,0.06≤y≤0.16)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2023年第10期41卷 1478-1486,I0001页

作者： Yuxing Bai Liwei Wu Qilin Cheng Li Wu Yongfa Kong Yi Zhang jingjun xu Key Laboratory of Weak-Light Nonlinear Photonics Ministry of EducationSchool of PhysicsNankai UniversityTianjin300071China College of Science Civil Aviation University of ChinaTianjin300300China Institute of Photo-electronic Thin Film Devices and Technology Nankai UniversityTianjin300071China

Thermal stability is a crucial index to assess application value of high-power LEDs,which is related to lattice ***,an effective structure-engineering strategy is proposed to achieve excellent *** the 394 nm excitation,Cs_3Zn_(5.94)B_9O_(21):0.06Eu^(3+)possesses two characteristic emissions peaked at 591 and 612 nm with limited thermal *** introducing Li^(+)ions into the lattice,the sample exhibits high color purity and excellent zero-thermal quenching because the defect contents of the phosphor can be effectively modulated via charge-compensation ***,under the stimulus of high temperature,the corresponding trap levels with a suitable depth(E=1.27 eV)will release electrons to recombine with the luminescent centers,compensating for the energy *** study provides a meaningful guide for optimizing and designing novel functional photoluminescent materials.

关键词： Photoluminescence Charge compensation Lattice defects Thermal stability Rare earths

Mode characteristics of silver-coated inverted-wedge silica microdisks

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2015年第11期58卷 40-44页

作者： BO Fang WANG XiaoOu LI Ying GAO Feng ZHANG GuoQuan xu jingjun The Key Laboratory of Weak-Light Nonlinear Photonics Ministry of Education TEDA Applied Physics Institute and School of PhysicsNankai University

The characteristics of whispering gallery modes(WGM) in silver-coated inverted-wedge silica microdisks are theoretically investigated by using finite element method. Dielectric TE mode always exists in silver-coated inverted-wedge resonators; dielectric TM mode tends to couple with SPP modes; only pure interior surface plasmonic polariton(SPP) mode but not pure exterior SPP mode is observed in contrast to the metal-coated cylindrical and toroidal resonators. The dependence of quality factor of different kinds of WGMs on the radius of the resonator and the thickness of the coated silver layer are systematically analyzed. We find that the quality factors of the hybrid WGMs associated with SPP mode can reach 104. The maximum light intensity enhancement in ambient for a hybrid mode consisting of a dielectric TM mode and an exterior SPP mode can be obtained when a silver film of thickness ~40 nm is deposited. The silver-coated inverted-wedge silica resonators may be widely applied in sensing and surface enhanced Raman scattering.

关键词： microcavity whispering gallery mode surface plasmonic polariton