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Science China(Physics,Mechanics & Astronomy) 2008年第5期51卷 519-531页

作者： z.j.yang A.j.DEEKS College of Civil Engineering and Architecture Zhejiang University School of Civil and Resource Engineering University of Western Australia

A frequency-domain approach based on the semi-analytical scaled boundary finite element method(SBFEM) was developed to calculate dynamic stress intensity factors(DSIFs) at bimaterial interface cracks subjected to transient ***-cause the stress solutions of the SBFEM in the frequency domain are analytical in the radial direction,and the complex stress singularity at the bimaterial interface crack tip is explicitly represented in the stress solutions,the mixed-mode DSIFs were calculated directly by *** complex frequency-response functions of DSIFs were then used by the fast Fourier transform(FFT) and the inverse FFT to calculate time histories of DSIFs.A benchmark example was *** re-sults were obtained by modelling the example with a small number of degrees of freedom due to the semi-analytical nature of the SBFEM.

关键词： scaled boundary finite element method bimaterial interface crack frequency domain dynamic stress intensity factors fast Fourier transform

Temperature-controlled mode selection of Er-doped random fiber laser with disordered Bragg gratings

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Photonics Research 2016年第3期4卷 102-105页

作者： W.L.zhang Y.B.Song X.P.zeng R.Ma z.j.yang Y.j.Rao Key Laboratory of Optical Fiber Sensing & Communications (Education Ministry of China) University of Electronic Science & Technology of China

In this paper, we proposed a way to realize an Er-doped random fiber laser(RFL) with a disordered fiber Bragg grating(FBG) array, as well as to control the lasing mode of the RFL by heating specific locations of the disordered FBG array. The disordered FBG array performs as both the gain medium and random distributed reflectors, which together with a tunable point reflector form the RFL. Coherent multi-mode random lasing is obtained with a threshold of between 7.5 and 10 mW and a power efficiency between 23% and 27% when the reflectivity of the point reflector changes from 4% to 50%. To control the lasing mode of random emission, a specific point of the disordered FBG array is heated so as to shift the wavelength of the FBG(s) at this point away from the other ***, different resonance cavities are formed, and the lasing mode can be controlled by changing the location of the heating point.

关键词： mode Temperature-controlled mode selection of Er-doped random fiber laser with disordered Bragg gratings

Plasma response to supersonic molecular beam injection in j-TEXT

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Plasma response to supersonic molecular beam injection in J-...

第十六届全国等离子体科学技术会议暨第一届全国等离子体医学研讨会

作者： j.S.Xiao z.j.yang G.zhuang M.H.Liu State Key of Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology

Recently,hydrogen fueling experiments with Supersonic Molecular Beam Injection (SMBI) system were performed on the j-TEXT *** these experiments, besides the density increasing,several interesting phenomenon were *** the first place,when moderate SMB used,electron density increased with a large margin, accompanying that the scale of magnetic island slightly *** rotation,which measured by the velocity of CV ion with a spectroscopy(r/a= 0.7-0.8),accelerated from 8km/s to 12km/s(counter-current direction) during SMBI.A higher electron density than pre-SMBI maintained for long period,indicating plasma confinement may *** another hand,while the amount of SMB is sufficient enough,it can trigger the tearing *** the electron density increased *** of CV ion decreased,even reversed towards co-current *** electron temperature changed like non-local have been ***,we need to find more evidence to prove it.

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High conductive gate leakage current channels induced by In segregation around screw- and mixed-type threading dislocations in lattice-matched InxAl1-xN/GaN heterostructures

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High conductive gate leakage current channels induced by In ...

第十二届全国MOCVD学术会议

作者： F.j.Xu j.Song C.C.Huang X.Q.Wang z.j.yang B.Shen State Key Laboratory of Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking University

The Ⅲ-nitride alloys are important in the development of optoelectronic and microwave high-power device *** them,the InAlN alloys are much less investigated than InGaN and AlGaN,because it is very difficult to obtain high-quality InAlN layers for the significant difference of thermal stability between InN and AlN.

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Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/CdS heterojunction with photothermal effect for efficient photocatalytic hydrogen production

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journal of Materials Science & Technology 2024年第4期171卷 1-9页

作者： T.Y.Huang z.yang S.Y.yang z.H.Dai Y.j.Liu j.H.Liao G.Y.zhong z.j.Xie Y.P.Fang S.S.zhang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China School of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/CdS heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)CdS nanosheets on 2D MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous *** unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of *** irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of CdS *** study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure Heterostructure Photothermal effect Photocatalyst Hydrogen evolution

The Microwave Interferometer on j-TEXT Tokamak

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The Microwave Interferometer on J-TEXT Tokamak

The 8th International Symposium on Antennas,Propagation and EM Theory（ISAPE2008）

作者： L.Gao,G.zhuang,X.W.Hu z.j.yang College of Electrical and Electronic Engineering,Huazhong University of Science and Technology,Wuhan,Hubei 430074,China

A 2 mm microwave interferometer is developed to measure plasma electron density for the j-TEXT *** interferometer views the plasma vertically through a set of large diagnostic ports and the system is configured as a f... 详细信息

关键词： The Microwave Interferometer on j-TEXT Tokamak

Ga1-xMnxN Grown by Low Pressure Metalorganic Chemical Vapor Deposition and application in polarized LED

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Ga1-xMnxN Grown by Low Pressure Metalorganic Chemical Vapor ...

The Eighth Chinese Optoelectronics Symposium

作者： z.T.Chen, Y.Y.Su, Y.zhang, B.zhang, z.j.yang, K.Xu, Y.B.Pan, and G.Y.zhang School of Physics, Research Center for Wide-band Semiconductors State Key Laboratory for Artificial Microstructure and Mesoscopic Physics Peking University, Beijing 100871

Epitaxial ms of GalMnxN have been grown on c-sapphire substrates by low-pressure metal-organic vapour phase epitaxy. The samples show ferromagnetic behaviour up to a temperature of T = 380K with hysteresis curves showing a coercivity of 50-100 Oe. No ferromagnetic second phases and no significant deterioration in crystal quality with the incorporation of Mn can be detected by high-resolution x-ray diaction. The result of x-ray absorption near-edge structures indicates that Mn atoms substitute for Ga atoms. The Mn concentrations of the layers are determined to reach x = 0.038 by proton-induced x-ray emission. The structure of light emitting diode with polarization light emitting was discussed.

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In situ digital testing method for quality assessment of soft soil improvement with polyurethane

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journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1732-1748页

作者： X.F.Wang C.j.Wang W.V.Yue z.j.zhang z.Q.Yue Department of Civil Engineering China University of Geosciences (Beijing)BeijingChina Department of Water Science and Engineering Zhengzhou UniversityZhengzhouChina Department of Geotechnical Engineering Tongji UniversityShanghaiChina Department of Civil Engineering The University of Hong KongChina

This study purposes an in situ testing method on quality assessment of soil *** drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring *** factual drilling data can characterize the degree of soil improvement by penetration injection with permeable *** from on-site drilling monitoring shows that the linear zones represent constant drilling speeds shown in the plot of drill bit advancement *** drilling time,which indicates the spatial distributions of soil *** soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky *** results of soil profile are verified by the parallel site *** constant drilling speeds profile the coring-resistant strength of drilled *** comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty *** tests,*** compressive strength(UCS)test,have been performed with core sample to investigate and characterize in situ strength by comparing that with drilling *** show that the average predicted strengths of treated silty clay are 2.4-6.9 times higher than the average measured strength of untreated silty *** UCS-based indices of 374.5%and 344.2%verified the quality assessment(QA)results by this new in situ *** method provides a cost-effective tool for quality assessment of soil improvement by utilizing the digital drilling data.

关键词： Drilling process monitoring system Hydraulic rotary drilling process Constant drilling speed Soil improvement Quality assessment

Four Late-type Galaxies with Double Radio Lobes and Properties of Such Galaxies

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Research in Astronomy and Astrophysics 2024年第4期24卷 84-90页

作者： z.S.Yuan X.Y.Gao z.L.Wen j.L.Han National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

The triggering mechanism for radio lobes from late-type galaxies is not fully *** samples are desired for a thorough investigation and *** utilizing the optical data from the newly released Dark Energy Spectroscopic Instrument imaging surveys and the radio sources from the NRAO VLA Sky Survey and the Faint Images of the Radio Sky at Twenty-centimeter,we identify four Late-type Galaxies with double Radio Lobes(La GRLs):j0217-3645,j0947+6220,j1412+3723 and j1736+*** previously known La GRLs,we confirm the correlation between radio power P_(1.4GHz)and stellar mass M_(*)of host ***(25/35)La GRLs belong to the blue cloud galaxies,while the newly identified cases in this work are located within the region of the red *** find a clear correlation between the differential radio power,i.e.,the offset from the P_(1.4GHz)-M_(*)relation,and the galaxy color,indicating that bluer galaxies at a fixed M_(*)tend to host more powerful radio ***,the majority(31/36)of La GRLs are either located in a galaxy group or displaying a disturbed *** suggest that all of the galaxy mass,color and surrounding environment could play important roles in triggering radio lobes in late-type galaxies.

关键词： galaxies:active galaxies:jets galaxies:spiral radio continuum:galaxies

An Improved Image Steganography Security and Capacity Using Ant Colony Algorithm Optimization

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Computers, Materials and Continua 2024年第3期80卷 4643-4662页

作者： jasim z.K.j. Kurnaz S. Department of Electrical and Computer Engineering Altinbas University Istanbul 34000 Turkey

This advanced paper presents a new approach to improving image steganography using the Ant Colony Optimization (ACO) algorithm. Image steganography, a technique of embedding hidden information in digital photographs, should ideally achieve the dual purposes of maximum data hiding and maintenance of the integrity of the cover media so that it is least suspect. The contemporary methods of steganography are at best a compromise between these two. In this paper, we present our approach, entitled Ant Colony Optimization (ACO)-Least Significant Bit (LSB), which attempts to optimize the capacity in steganographic embedding. The approach makes use of a grayscale cover image to hide the confidential data with an additional bit pair per byte, both for integrity verification and the file checksum of the secret data. This approach encodes confidential information into four pairs of bits and embeds it within uncompressed grayscale images. The ACO algorithm uses adaptive exploration to select some pixels, maximizing the capacity of data embedding while minimizing the degradation of visual quality. Pheromone evaporation is introduced through iterations to avoid stagnation in solution refinement. The levels of pheromone are modified to reinforce successful pixel choices. Experimental results obtained through the ACO-LSB method reveal that it clearly improves image steganography capabilities by providing an increase of up to 30% in the embedding capacity compared with traditional approaches; the average Peak Signal to Noise Ratio (PSNR) is 40.5 dB with a Structural Index Similarity (SSIM) of 0.98. The approach also demonstrates very high resistance to detection, cutting down the rate by 20%. Implemented in MATLAB R2023a, the model was tested against one thousand publicly available grayscale images, thus providing robust evidence of its effectiveness. Copyright © 2024 The Authors. Published by Tech Science Press.

关键词： ant colony algorithm capacity optimization steganalysis Steganography