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Simultaneous measurement of strain and temperature using Fabry–Pérot interferometry and antiresonant mechanism in a hollow-core fiber

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Chinese Optics Letters 2021年第4期19卷 22-27页

作者： Chong He Cheng Zhou Qian Zhou Shiyi Xie Mengzhe Xiao jiajun tian Yong Yao School of Electronics and Information Engineering Harbin Institute of TechnologyShenzhen 518055China

A fiber-optic sensor for the simultaneous measurement of strain and temperature is proposed and experimentally demonstrated based on Fabry–Pérot(FP) interference and the antiresonance(AR) mechanism. The sensor was implemented using a single-mode fiber(SMF)–hollow-core fiber–SMF structure. A temperature sensitivity of 21.11 pm/℃ was achieved by tracing the troughs of the envelope caused by the AR mechanism, and a strain sensitivity of 2 pm/με was achieved by detecting the fine fringes caused by the FP cavity. The results indicate that the dual-parameter sensor is stable and reliable.

关键词： fiber-optic sensor Fabry–Pérot interference antiresonance

A Continuum One——Dimensional Model for Radionuclide Migration Testing in Unsaturated Loess

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Journal of Earth Science 1991年第1期10卷 126-130页

作者： Chen jiajun Xu Zhaoyi tian KaimingChina University of Geostiences , Beijing 100083 tian JipingGuangzhou University , Guangzhou 510050

Unsaturated radionuclide migration experiments were conducted in a pit inside the testing hall. Several types of radionuclides were used in the experiments . Tritium was used as a tracer for water movement in unsaturated loess . Other kinds of radionuclides were also used in order to obtain fundamental parameters for radionuclide migration so that further environmental assessment of low-level radioactive waste disposal can be carried out . Mechanisms governing unsaturated flow in loess , that is , principles of one-way lateral flow , are presented qualitatively in this paper . And a continuum one-dimensional model for radionuclide migration testing is developed based on the experiments conducted under the particular conditions at the test site . The data measured from the tests were compared with solutions of this one -dimensional model . Results show that this model is feasible for modeling radionuclide migration in unsaturated loess .

关键词： radionuclide migration the tracer layer loess environmental assessment.

Hydrogel bioadhesives harnessing nanoscale phase separation for Achilles tendon repairing

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Nano Research 2024年第2期17卷 778-787页

作者： Jun Zhang Xingmei Chen Jingseng Lin Pei Zhang Iek Man Lei Yue Tao jiajun Zhang tian Luo Ji Liu Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055China Research and Innovation Center SKG Health TechnologyShenzhen 518000China SAFE(Shenzhen)Medical Technology Company Limited Shenzhen 518000China Shenzhen Key Laboratory of Biomimetic Robotics and Intelligent Systems Department of Mechanical and Energy EngineeringSouthern University of Science and TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Human-Augmentation and Rehabilitation Robotics in Universities Southern University of Science and TechnologyShenzhen 518055China

Repairing Achilles tendon has emerged as a long-standing challenge in the orthopaedic *** suture is the gold standard for re-attaching and repairing the fractured Achilles tendons in clinical surgeries,it is still subjected to numerous adverse side-effects,including chronic inflammatory,tendon tissue re-rupture,scar formation,and post-surgical peritendinous *** this work,we develop a class of hydrogel bioadhesives with tailored nanoscale phase separation for Achilles tendon *** address the existing limitations of sutures,our hydrogel bioadhesives encompass three core functionalities:(i)instant and tough adhesion to Achilles tendon tissues,(ii)extraordinary long-term adhesion robustness under wet and dynamic in vivo conditions,and(iii)anti-postsurgical peritendinous *** our hydrogel bioadhesives with sutures,such kind of integrated approach enables a conformable yet robust biointerface with the tendon tissues,and prevents the fibroblast migration and formation of connective tissues,thus facilitating the tendon *** hydrogel bioadhesives reported here open up new opportunities for the repairing of fractured Achilles tendons in diverse and complicated clinical scenarios.

关键词： hydrogels phase separation bioadhesion robustness tendon repairing

On the Identification of N-rich Metal-poor Field Stars with Future Chinese Space Station Telescope

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Research in Astronomy and Astrophysics 2024年第1期24卷 151-164页

作者： jiajun Zhang Baitian Tang Jiang Chang Xiangxiang Xue JoséGFernández-Trincado Chengyuan Li Long Wang Hao tian Yang Huang School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China CSST Science Center for the Guangdong-Hong Kong-Macao Greater Bay Area Sun Yat-sen UniversityZhuhai 519082China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210034China Key Lab of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Instituto de Astronomía Universidad Católica del NorteAv.Angamos 0610AntofagastaChile Key Lab of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

During the long term evolution of globular clusters(GCs), some member stars are lost to the field. The recently found nitrogen-rich(N-rich) metal-poor field stars are promising candidates of these GC escapees, since N enhancement is the fingerprint of chemically enhanced populations in GCs. In this work, we discuss the possibility of identifying N-rich metal-poor field stars with the upcoming Chinese Space Station Telescope(CSST). We focus on the main survey camera with NUV, u, g, r, i, z, y filters and slitless spectrograph with a resolution about *** combination of UV sensitive equipment and prominent N-related molecular lines in the UV band bodes well for the identification: the color–color diagram of(u-g) versus(g-r) is capable of separating N-rich field stars from normal halo stars, if metallicity can be estimated without using the information on u-band ***, the synthetic spectra show that a signal-to-noise ratio of 10 is sufficient to identify N-rich field stars. In the near future, a large sample of N-rich field stars found by CSST, combined with state-of-the-art N-body simulations will be crucial to deciphering GC-Galaxy co-evolution.

关键词： stars:chemically peculiar stars:abundances techniques:photometric techniques:spectroscopic

Asymmetric frequency multiplexing topological devices based on a floating edge band

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Photonics Research 2024年第6期12卷 1201-1212页

作者： jiajun MA CHUNMEI OUYANG YUTING YANG DONGYANG WANG HONGYI LI LI NIU YI LIU QUAN XU YANFENG LI ZHEN tian JIAGUANG HAN WEILI ZHANG Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering and Key Laboratory of Optoelectronics Information and TechnologyTianjin UniversityTianjin 300072China School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China Optoelectronics Research Centre University of SouthamptonSouthampton SO171BJUK Guangxi Key Laboratory of Optoelectronic Information Processing School of Optoelectronic EngineeringGuilin University of Electronic TechnologyGuilin 541004China School of Electrical and Computer Engineering Oklahoma State UniversityStillwaterOklahoma 74078USA

Topological photonics provides a platform for robust energy transport regardless of sharp corners and ***,the frequency multiplexing topological devices have attracted much attention due to the ability to separate optical signals by wavelength and hence the potential application in optical communication *** frequency multiplexing topological devices are generally based on the slow light ***,the resulting static local spatial mode or finely tuned flat band has zero-group velocity,making it difficult for both experimental excitation and channel ***,we propose and experimentally demonstrate an alternative prototype of asymmetric frequency multiplexing devices including a topological rainbow and frequency router based on floating topological edge mode(instead of localized ones);hence the multiple wavelength channels can be collectively excited with a point source and efficiently routed to separate output *** channel separation in our design is achieved by gradually tuning the band gap truncation on a topological edge band over a wide range of frequencies.A crucial feature lies in that the topological edge band is detached from bulk states and floating within the upper and lower photonic band *** interestingly,due to the sandwiched morphology of the edge band,the top and bottom band gaps will each truncate into transport channels that support topological propagation towards opposite directions,and the asymmetrical transportation is realized for the frequency multiplexing topological devices.

关键词： tuning floating hence

Analysis of wheel-rail adhesion redundancy considering the thirdbody medium on the rail surface

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Railway Sciences 2024年第2期3卷 156-176页

作者： Chun tian Gengwei Zhai Mengling Wu jiajun Zhou Yaojie Li Institute of Rail Transit Tongji UniversityShanghaiChina

Purpose–In response to the problem of insufficient traction/braking adhesion force caused by the existence of the third-body medium on the rail surface,this study aims to analyze the utilization of wheel-rail adhesion coefficient under different medium conditions and propose relevant measures for reasonable and optimized utilization of adhesion to ensure the traction/braking performance and operation safety of ***/methodology/approach–Based on the PLS-160 wheel-rail adhesion simulation test rig,the study investigates the variation patterns of maximum utilized adhesion characteristics on the rail surface under different conditions of small creepage and large *** statistical analysis of multiple sets of experimental data,the statistical distribution patterns of maximum utilized adhesion on the rail surface are obtained,and a method for analyzing wheel-rail adhesion redundancy based on normal distribution is *** study analyzes the utilization of traction/braking adhesion,as well as adhesion redundancy,for different medium under small creepage and large slip *** on these findings,relevant measures for the reasonable and optimized utilization of adhesion are ***–When the third-body medium exists on the rail surface,the train should adopt the low-level service braking to avoid the braking skidding by extending the braking *** with the current adhesion control strategy of small creepage,adopting appropriate strategies to control the train’s adhesion coefficient near the second peak point of the adhesion coefficient-slip ratio curve in large slip can effectively improve the traction/braking adhesion redundancy and the upper limit of adhesion utilization,thereby ensuring the traction/braking performance and operation safety of the ***/value–Most existing studies focus on the wheel-rail adhesion coefficient values and variation patterns under different medium conditions,without considering wheth

关键词： Wheel-rail adhesion redundancy PLS-160 wheel-rail adhesion simulation test rig Normal distribution Utilized adhesion coefficient

Bidirectional rectifier with gate voltage control based on Bi_(2)O_(2)Se/WSe_(2)heterojunction

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Journal of Semiconductors 2024年第1期45卷 63-70页

作者： Ruonan Li Fangchao Lu jiajun Deng Xingqiu Fu Wenjie Wang He tian North China Electric Power University and Hebei Key Laboratory of Physics and Energy Technology Beijing 102206China School of Integrated Circuits&Beijing National Research on Information Science and Technology(BNRist) Tsinghua UniversityBeijing 100084China

Two-dimensional(2D)WSe_(2)has received increasing attention due to its unique optical properties and bipolar *** WSe_(2)-based heterojunctions exhibit bidirectional rectification characteristics,but most devices have a lower rectification *** this work,the Bi_(2)O_(2)Se/WSe_(2)heterojunction prepared by us has a typeⅡband alignment,which can vastly suppress the channel current through the interface barrier so that the Bi_(2)O_(2)Se/WSe_(2)heterojunction device has a large rectification ratio of about 10^(5).Meanwhile,under different gate voltage modulation,the current on/off ratio of the device changes by nearly five orders of magnitude,and the maximum current on/off ratio is expected to be achieved *** photocurrent measurement reveals the behavior of recombination and space charge confinement,further verifying the bidirectional rectification behavior of heterojunctions,and it also exhibits excellent performance in light *** the future,Bi_(2)O_(2)Se/WSe_(2)heterojunction field-effect transistors have great potential to reduce the volume of integrated circuits as a bidirectional controlled switching device.

关键词： Bi_(2)O_(2)Se WSe_(2) heterojunction bidirectional rectification optoelectronic devices

Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

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Chinese Physics B 2024年第6期33卷 63-67页

作者：陈佳骏吕心邓李思敏但雅倩黄艳萍崔田 Institute of High Pressure Physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical ***,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical *** to 70 GPa,an unusual metal-semiconductor-metal transition *** first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti *** electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered *** pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase *** assign the most probable space group as P2_(1)2_(1)2_(1).Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

关键词： high pressure transition metal dichalcogenides doped TiS_(2) electronic phase transition

Research of the light reflex surface defects detection technology

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Research of the light reflex surface defects detection techn...