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Oxidation Resistance of In Situ Reaction/Hot Pressing Synthesized Ti_(2)AlC-20%TiB_(2) Composite at 600-900℃in Air

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 739-748页

作者： Wenting Wang jingjun xu Jun Zuo Ke Ma Yang Li Guangqi He Meishuan Li Shengyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China

The oxidation behavior and kinetics of Ti_(2)AlC-20vol.%TiB_(2) composite at 600-900℃ in air were *** results showed that the oxidation kinetics of the composite followed a logarithmic law within the given temperature range,which indicated that the composites had excellent oxidation *** selective oxidation of Al in Ti_(2)AlC was greatly enhanced,which facilitated the formation of a continuous and dense protective layer of Al_(2)O_(3).Meanwhile,the existence of molten B_(2)O_(3) inhibited the outward diffusion of Ti and inward diffusion of oxygen,which prevented the growth of anatase TiO_(2) at 600℃ and rutile TiO_(2) at 700-900℃.Therefore,the incorporation of TiB_(2) completely inhibited the abnormally rapid oxidation of bulk Ti_(2)AlC at 600℃ and improved its oxidation resistance at 700-900℃.

关键词： MAX phase Ti_(2)AlC-TiB_(2)composite Intermediate temperature oxidation Oxidation kinetics

Lens-Like Effect in LiNbO_(3) : Fe Photorefractive Crystal

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Chinese Physics Letters 1993年第5期10卷 306-309页

作者： xu jingjun LIU Junmin ZHANG Guangyin LIU Simin Department of Physics Nankai UniversityTianjin 300071

The lens-like effects,both photorefractive effect and thermo-optical effect,were studied in the LiNbO_(3):Fe *** threshold light intensity above which the photorefractive effect was overwhelmed b-v the thermal effect was determined and the thermo-optical coefficient dn/dT is evaluated by the Z-scanning *** limiting characteristics of LiNbO_(3):Fe sheet is examined.

关键词： effect (3) Crystal

Giant Kerr nonlinearity of terahertz waves mediated by stimulated phonon polaritons in a microcavity chip

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Light(Science & Applications) 2024年第10期13卷 2231-2239页

作者： Yibo Huang Yao Lu Wei Li Xitan xu Xinda Jiang Ruobin Ma Lu Chen Ningjuan Ruan Qiang Wu jingjun xu The Key Laboratory of Weak-Light Nonlinear Photonics Ministry of EducationTEDA Applied Physics Institute and School of PhysicsNankai UniversityTianjin 300071China Shenzhen Research Institute of Nankai University Shenzhen 518083 GuangdongChina Beijing Institute of Space Mechanics&Electricity China Academy of Space Technology100094 BeijingChina

Optical Kerr effect, in which input light intensity linearly alters the refractive index, has enabled the generation ofoptical solitons, supercontinuum spectra, and frequency combs, playing vital roles in the on-chip devices, fibercommunications, and quantum manipulations. Especially, terahertz Kerr effect, featuring fascinating prospects in futurehigh-rate computing, artificial intelligence, and cloud-based technologies, encounters a great challenge due to therather low power density and feeble Kerr response. Here, we demonstrate a giant terahertz frequency Kerr nonlinearitymediated by stimulated phonon polaritons. Under the influences of the giant Kerr nonlinearity, the power-dependentrefractive index change would result in a frequency shift in the microcavity, which was experimentally demonstratedvia the measurement of the resonant mode of a chip-scale lithium niobate Fabry-Pérot microcavity. Attributed to theexistence of stimulated phonon polaritons, the nonlinear coefficient extracted from the frequency shifts is orders ofmagnitude larger than that of visible and infrared light, which is also theoretically demonstrated by nonlinear Huangequations. This work opens an avenue for many rich and fruitful terahertz Kerr effect based physical, chemical, andbiological systems that have terahertz fingerprints.

关键词： nonlinearity phonon resonant

Transient-State and Steady-State Light-Induced Scattering in Photorefractive Crystal LiNbO_(3):Fe

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Chinese Physics Letters 1994年第5期11卷 269-272页

作者： LIU Junmin LIU Simin xu jingjun ZHANG Guangyin XIONG Guisheng MEN Liqiu GUO Ru Department of Physics Nankai UniversityTianjin 300071

We found that drift-length of light-excited electrons L0 has influence upon the light-induced scattering in LiNbO_(3):Fe *** proposed that one of the necessary conditions for steady-state light-induced scattering is D... 详细信息

关键词： crystal illumination excited

A novel medium-entropy(TiVNb)_(2)AlC MAX phase:Fabrication,microstructure,and properties

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Journal of Materials Science & Technology 2023年第6期137卷 91-99页

作者： Guangqi He Yi Zhang Pei Yao Xingchao Li Ke Ma Jun Zuo Meishuan Li Changsheng Liu jingjun xu School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Science and Technology on Advanced Functional Composites Laboratory Aerospace Research Institute of Material and Processing TechnologyBeijing 100076China

Medium-or high-entropy materials have great potential for applications due to their diverse compo-sitions and unexpected physicochemical ***,a novel medium-entropy(TiVNb)_(2)AlC was synthesized via hot pressing at 1400℃from three individual M_(2)AlC(M=Ti,V,Nb)MAX *** microstructure of(TiVNb)_(2)AlC was characterized from the microscale to the atomic scale by scanning electron microscope microscopy(SEM),scanning transmission electron microscopy(STEM),and energy dispersive spectroscopy(EDS).The results showed that Ti,V,and Nb atoms were fully solid-soluble in the M-sites of the M_(2)AlC MAX *** with three individual MAX phases,the thermal conduc-tivity of(TiVNb)_(2)AlC was reduced greatly in the temperature range of 293-1473 K,and its mechanical properties(including Young’s modulus,Vickers hardness,and bending strength)were all increased due to the solid solution strengthening and electronic mechanism.

关键词： Medium-entropy ceramics MAX phases Microstructure Thermal properties Mechanical properties

Microstructure and mechanical properties of short-carbon-fiber/Ti_(3)SiC_(2) composites

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Journal of Advanced Ceramics 2020年第6期9卷 716-725页

作者： Guangqi HE Rongxiu GUO Meishuan LI Yang YANG Linshan WANG Yuhai QIAN Jun ZUO jingjun xu Changsheng LIU School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China College of Science Northeastern UniversityShenyang 110819China

Short-carbon-fibers(C_(sf))reinforced Ti_(3)SiC_(2) matrix composites(C_(sf)/Ti_(3)SiC_(2),the C_(sf) content was 0 vol%,2 vol%,5 vol%,and 10 vol%)were fabricated by spark plasma sintering(SPS)using Ti_(3)SiC_(2) powders and C_(sf) as starting materials at 1300℃.The effects of C_(sf) addition on the phase compositions,microstructures,and mechanical properties(including hardness,flexural strength(σ_(f)),and KIC)of C_(sf)/Ti_(3)SiC_(2) composites were *** C_(sf),with bi-layered transition layers,i.e.,T_(IC) and SiC layers,were homogeneously distributed in the as-prepared C_(sf)/Ti_(3)SiC_(2) *** the increase of C_(sf) content,the K_(IC) of C_(sf)/Ti_(3)SiC_(2) composites increased,but the σ_(f) decreased,and the Vickers hardness decreased initially and then increased steadily when the C_(sf) content was higher than 2 vol%.These changed performances(hardness,σ_(f),and K_(IC))could be attributed to the introduction of C_(sf) and the formation of stronger interfacial phases.

关键词： Ti_(3)SiC_(2) short-carbon-fibers(C_(sf)) spark plasma sintering(SPS) microstructure mechanical properties

维普期刊数据库

Temperature dependence of photoluminescence of QD arrays

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Frontiers of Optoelectronics 2008年第Z2期1卷 258-262页

作者： Guoliang LIU Jianghong YAO jingjun xu Zhanguo WANG The Key Laboratory of Advanced Technique and Fabrication for Weak-Light Nonlinear Photonics Materials Tianjin Key Laboratory of Photonics Materials and Technology for Information Science TEDA Applied Physics School Nankai University Institute of Semiconductors Chinese Academy of Sciences

It is essentially important to understand the temperature dependence of the photoluminescence of multimodal quantum dot(QD) arrays for the realization of efficient photonic devices. In this paper, the dynamics processes of different density multimodal QD arrays were fitted by using the rate equation model. It is shown that, in high density QD arrays, the intensity of photoluminescence of different QD families has different temperature dependence, and the intensity of photoluminescence is quenched as the temperature increases in low density QD arrays. In high density QD arrays, as the temperature increases, the carriers will be thermally excited into the wetting layer from QDs, and then some of them will be recaptured by the big scale QDs; carrier coupling takes place between the different QD families, while in low density QD arrays, the carrier transfer between different QD families will be limited. Temperature dependence of the maximum of the ratio of photoluminescence intensity of different QD families strongly depends on the difference of thermal activation energies.

关键词： optoelectronics rate equation photoluminescence multimodal quantum dot (QD) arrays thermally excited

Efficient second and third harmonic generation in dual-layer lithium niobate microdisk resonator

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 33-38页

作者： Zhenzhong Hao Xiao Wu Qiang Luo Zhang Li Rui Ma Fang Bo Feng Gao Guoquan Zhang jingjun xu MOE Key Laboratory of Weak-Light Nonlinear Photonics TEDA Institute of Applied Physics and School of PhysicsNankai UniversityTianjin 300457China

Lithium niobate thin film frequency doubler has extensive applications in the preparation of classical and quantum *** this study,we successfully fabricated microdisk resonators with a quality factor of 2.2×10^(5) in reverse-polarization dual-layer x-cut lithium niobate for the first *** on the modal phase matching condition,efficient second harmonic generation with a record normalized conversion efficiency of~56000%W-1 and cascaded third harmonic generation with an efficiency of~6500%W-2 were obtained in the microdisk *** with the periodically poled lithium niobate microcavity,the complex domain structure preparation processes are *** work provides a scheme for achieving highly efficient second-order nonlinear effects in non-periodically poled microcavities.

关键词： harmonic lithium niobate

维普期刊数据库

All-optical modulation of quantum states by nonlinear metasurface

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Light(Science & Applications) 2022年第3期11卷 136-141页

作者： Di Zhang Yang Chen Shengchao Gong Wei Wu Wei Cai Mengxin Ren Xifeng Ren Shuang Zhang Guangcan Guo jingjun xu The Key Laboratory of Weak-Light Nonlinear Photonics Ministry of EducationSchool of Physics and TEDA Applied Physics InstituteNankai UniversityTianjinChina Key Laboratory of Quantum Information CASUniversity of Science and Technology of ChinaHefeiChina Synergetic Innovation Center of Quantum Information&Quantum Physics University of Science and Technology of ChinaHefeiChina Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuanChina Department of Physics The University of Hong KongHong KongChina

Metasurfaces have proven themselves an exotic ability to harness light at nano-scale,being important not only for classical but also for quantum *** manipulation of the quantum states is at the heart of quantum information processing;however,such function has been rarely realized with metasurfaces so ***,we report an all-optical dynamic modulation of the photonic quantum states using the nonlinear *** metasurface consists of a metallic nanostructure combined with a photoisomerizable azo *** tuning the plasmonic resonance through optically switching the azo molecules between their binary isomeric states,we have realized dynamic control of transmission efficiencies of orthogonally polarized photons and also the phase delay between them,thereby an entangled state was efficiently *** an illustration,a quantum state distillation has been demonstrated to recover a Bell state from a non-maximally entangled one to that with fidelities higher than 98%.Our work would enrich the functions of the metasurface in the quantum world,from static to dynamic modulation,making the quantum metasurface going practical.

关键词： surface quantum nonlinear