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laser-based directed energy deposition of novel Sc/Zr-modified Al-Mg alloys:columnar-to-equiaxed transition and aging hardening behavior

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Journal of Materials Science & Technology 2021年第10期69卷 168-179页

作者： Zihong Wang Xin Lin Yao Tang Nan Kang Xuehao Gao Shuoqing Shi Weidong Huang State Key laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China Key laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT ChinaNorthwestern Polytechnical UniversityXi'an 710072China

The control of grain morphology is important in laser additive manufacturing(LAM),as grain morphology further affects the hot cracking resistance,anisotropy,and strength–ductility synergy of *** develop a solidification-control solution and achieve columnar-to-equiaxed transition(CET)in Al-based alloys during LAM,Sc-and-Zr-modified Al-Mg alloys were processed via directed energy deposition(DED).CET was achieved by introducing high potent primary Al_(3)(Sc,Zr)nucleation sites ahead of the solidification ***,the relationship between the solidification control parameters and precipitation behavior of primary Al_(3)(Sc,Zr)nucleation sites was established using the time-dependent nucleation ***,the CET was studied according to the Hunt *** results indicated that coarse columnar grain structure was still obtained at the inner region of the molten pool at low Sc/Zr contents owing to the effective suppression of the precipitation of the primary Al_(3)(Sc,Zr)nucleation sites via rapid solidification during *** addition,the relatively low melt temperature at the fusion boundary unavoidably promoted the precipitation of primary Al_(3)(Sc,Zr)nucleation sites,which resulted in a fine equiaxed grains band at the edge of the molten *** the Sc/Zr content increased,the solidification cooling rate was not sufficient to suppress the precipitation of the primary Al_(3)(Sc,Zr)nucleation sites,and a fully equiaxed grain structure was ***,the effect of the layer-by-layer manufacturing process on the subsequent precipitation strengthening of secondary Al_(3)(Sc,Zr)precipitates was *** the remelting and subsequent aging during thermal cycling should be considered to achieve greater precipitation strengthening.

关键词： Al-Mg-Sc-Zr alloys Additive manufacturing Directed energy deposition Columnar-to-equiaxed transition Phase precipitation

Tape casting of a YAG/Yb:YAG/YAG transparent ceramic for a broadband tunable laser

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High Power laser Science and Engineering 2014年第4期2卷 58-61页

作者： Chao Wang Wenxue Li Xianghui Yang Dongbi Bai Kangwen Yang Xuewei Ba Jiang Li Yubai Pan Heping Zeng State Key laboratory of Precision Spectroscopy East China Normal University Key laboratory of Transparent Opt-functional Inorganic Materials Shanghai Institute of Ceramics Chinese Academy of Sciences

A composite transparent YAG/Yb:YAG/YAG ceramic was prepared by a non-aqueous tape-casting method. An optical transmittance of 82% was obtained at visible wavelength and around 1100 nm. A low-threshold, broadband tunable continuous-wave(CW) laser at 1031 nm was further demonstrated from the ceramic sample, which was pumped by a974 nm fiber-pigtailed laser diode. The threshold pump power was 0.45 W and the maximum output power was 3.2 W,corresponding to a slope efficiency of 20.4%. By inserting an SF57 prism in the laser cavity, the output wavelength could be tuned continuously from 1021 to 1058 nm.

关键词： composite transparent ceramic solid-state laser broadband tunable wavelength

Metallomics:An integrated biometal science

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Science China Chemistry 2009年第12期52卷 2055-2070页

作者： GE RuiGuang1,2 & SUN HongZhe1 1 Department of Chemistry and Open laboratory of Chemical Biology,The University of Hong Kong,Hong Kong,China 2 laboratory of Integrative Biology,College of Life Sciences,Sun Yat-Sen University,Guangzhou 510006,China Department of Chemistry and Open laboratory of Chemical Biology The University of Hong Kong Hong Kong China laboratory of Integrative Biology College of Life Sciences Sun Yat-Sen University Guangzhou China

Metallomics is an emerging scientific area integrating the research fields related to the understanding of the molecular mechanisms of metal-associated life processes and the entirety of metal and metalloid species within a cell or tissue type. In metallomics,metalloproteins,metalloenzymes and other metal-containing biomolecules in a biological system are referred to as metallomes,similar to genomes and proteomes in genomics and proteomics,respectively. This review discusses the concept of metallomics with a focus on analytical techniques and methods,particularly the so-called hyphenated techniques which combine a high-resolution separation technique (gel electrophoresis/laser ablation,chromatography or capillary electrophoresis) with a highly sensitive detection method such as elemental (inductively coupled plasma,ICP) or molecular (electron spray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI)) mass spectrometry,or nuclear X-ray fluorescence/absorption spectrometry. The applications of these advanced analytical methods in the identification of metallo-/phospho-/seleno-proteins,probing of relationships between structure and function of metal-loproteins,and study of clinically used metallodrugs will be selectively outlined,along with their advantages and limitations.

关键词： metallomics metallome metallodrug metalloprotein chemical speciation

Single-mode output by controlling the spatiotemporal nonlinearities in mode-locked femtosecond multimode fiber lasers

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Advanced Photonics 2020年第5期2卷 84-91页

作者： Ugur Tegin Babak Rahmani Eirini Kakkava Demetri Psaltis Christophe Moser Ecole Polytechnique Fédérale de Lausanne Optics LaboratoryLausanneSwitzerland Ecole Polytechnique Fédérale de Lausanne Laboratory of Applied Photonics DevicesLausanneSwitzerland

The performance of fiber mode-locked lasers is limited due to the high nonlinearity induced by the spatial confinement of the single-mode fiber *** massively increase the pulse energy of the femtosecond pulses,amplification is performed outside the ***,spatiotemporal mode-locking has been proposed as a new path to fiber ***,the beam quality was highly multimode,and the calculated threshold pulse energy(>100 nJ)for nonlinear beam self-cleaning was challenging to *** present an approach to reach high energy per pulse directly in the mode-locked multimode fiber oscillator with a near single-mode output *** approach relies on spatial beam self-cleaning via the nonlinear Kerr effect,and we demonstrate a multimode fiber oscillator with M^2laser *** reported approach is further power scalable with larger core sized fibers up to a certain level of modal dispersion and could benefit applications that require high-power ultrashort lasers with commercially available optical fibers.

关键词： fiber lasers spatiotemporally mode-locked lasers multimode nonlinear fiber optics

Analytical solution of crystal diffraction intensity

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Chinese Physics B 2021年第11期30卷 430-433页

作者：尚万里孙奥杜华冰杨国洪韦敏习谢旭飞车兴森侯立飞张文海黎淼施军王峰何海恩杨家敏江少恩张保汉 Research Center of laser Fusion China Academy of Engineering PhysicsMianyang 621900China College of Optoelectronic Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Key laboratory of Optoelectronic Technology and Systems of the Education Ministry of China Chongqing UniversityChongqing 400030China

Plasma density and temperature can be diagnosed by x-ray line emission measurement with crystal,and bent crystals such as von Hamos and Hall structures are proposed to improve the diffraction *** this study,a straightforward solution for the focusing schemes of flat and bent crystals is *** with XOP code are performed to validate the analytical model,and good agreements are *** von Hamos or multi-cone crystal can lead to several hundred times intensity enhancements for a 200μm plasma *** model benefits the applications of the focusing bent crystals.

关键词： crystal diffraction analytic method x-ray diffraction

Fusing Thienoisoindigo to the Conjugated Ribbons with Strong Absorption in the Second Near-Infrared Window

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CCS Chemistry 2022年第11期4卷 3497-3504页

作者： Yu Jiang Yaogang Zhang Yunfeng Deng Shaoqiang Dong Bo Li Yuanping Yi Zebing Zeng Hanjiao Chen Hao Luo Yanhou Geng Joint School of National University of Singapore Tianjin UniversityInternational Campus of Tianjin UniversityBinhai New CityFuzhou 350207 School of Materials Science and Engineering Tianjin Key Laboratory of Molecular Optoelectronic ScienceTianjin UniversityTianjin 300072 Beijing National laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190 Institute ofMolecular Aggregation Science Tianjin UniversityTianjin 300072 State Key laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082 Analytical&Testing Center Sichuan UniversityChengdu 610064 School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China(UESTC)Chengdu 610054

Organic dyes with strong absorption in the second near-infrared(NIR-II)window(1000-1700 nm)have multiple ***,the design and synthesis of stable NIR-II absorbing organic dyes are very challenging and constantly defy our synthetic *** this work,we have successfully synthesized a series of soluble and stable fused thienoisoindigo(nThIID)*** absorption maximum(λ_(max))of the ribbons increases from 644 nm of 1ThIID to 1252 nm of ***,nThIIDs with n≥4 all display strong absorption in the NIR-II window with molar extinction coefficients(ε_(max))greater than 105 L mol^(−1)cm^(−1)atλ*** molecules are promising photothermal conversion dyes with photothermal conversion efficiencies of ca.60%under 1064 nm laser irradiation.

关键词： organic dyes second near-infrared window low bandgap thienoisoindigo conjugated molecules

Synthesis and micro-structural study of one-dimensional nano-materials

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Science China Mathematics 1999年第4期42卷 429-437页

作者：周光文张泽俞大鹏 Beijing laboratory of Electron Microscopy Center for Condensed Matter Physics Chinese Academy of Sciences Beijing China Department of Physics National Key Laboratory of Mesoscopic Physics Peking University Beijing China

Silicon nano-wires (SiNWs) and boron nitride nano-tubules (BN-NTs) were successfully synthesized by excimer laser ablation at high temperature. These one-dimensional nano-materials synthesized by this method have a very high yield, a uniform diameter distribution, and a high purity. Micro-structures of these nano-materials were investigated by transmission electron microscopy (TEM). The SiNWs have a high density of structural defects of microtwin, stacking faults, and low-angle boundary, which ere closely related to the formation of SiNWs and the determination of morphology of the nano-wires. BN-NTs ere mainly single atomic-layered and the outer surface of tubules is clean without any attachment. The formation of single atomic-layered tubule is attributed to the catalyst effect which makes the axial rate of BN-NTs much higher than the radial growth.

关键词： SiNWs structural defects morphology BN-NTs.

Investigation on the thermal conductivity of HDPE/MWCNT composites by laser pulse method

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Science China(Technological Sciences) 2009年第10期52卷 2767-2772页

作者： CHEN XinGui HE GuanHu DU JinHong PEI SongFeng GUO JingDong Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Thermal conductivity (TC) of high density polyethylene/multiwall carbon nanotube (HDPE/MWCNT) composite films was measured by laser pulse method. It is found that the TC increased quickly with the increase of MWCNT fraction when the volume fraction of MWCNT was below 3.35%. However,as the volume fraction of MWCNT was over 3.35%,the increasing rate became slow. A new percolation model was proposed based on the effect of MWCNT network to simulate the TC of HDPE/MWCNT composite films. The simulation result was in good agreement the experimental data well. In addition,the relationship of TC with the increase of temperature was also discussed.

关键词： HDPE/MWCNT composite thermal conductivity percolation model

Design of Seven-core Photonic Crystal Fiber with Flat In-phase Mode for Yb: Fiber laser Pumping

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Optics and Photonics Journal 2013年第2期3卷 197-201页

作者： Ruijuan Dong Peiguang Yan Gelin Zhang Huiquan Li Shuangchen Ruan Huifeng Wei Jie Luo Shenzhen key laboratory of laser engineering Shenzhen University College of Electronic Science and TechnologyShenZhen China State Key laboratory of Optical Fiber and Cable Manufacture Technology Yangtze Optical Fiber and Cable Company Ltd. R&D center Wuhan China

We numerically investigate the seven-core photonic crystal fiber (PCF) with the zero dispersion wavelength designed in the range of 1000 - 1080 nm, particularly suitable for the ytterbium-doped fiber laser pumping. Also, the PCFs are well designed for obtaining a flat in-phase mode by carefully adjusting the diameter of inner layer six holes, and the corresponding empirical values of fiber structure are summarized and listed. The variations of inner six holes to the amplitude of in-phase mode are further investigated, and our results show that a better tolerance can be achieved in the fiber structures with lower filling ratio configuration.

关键词： Photonic Crystal Fiber (PCF) In-phase Mode (IPM) Supercontinuum Generation (SCG)