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Microstructure of a Ti–50wt% Ta alloy produced via laser powder bed fusion

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Acta Metallurgica Sinica(English Letters) 2020年第7期33卷 981-990页

作者： Lei-Lei Xing cong-cong zhao Hao Chen Zhi-Jian Shen Wei Liu School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Jihua Laboratory 13th FloorChengye buildingNanping West Road No.13GuichengNanhai districtFoshan cityGuangdong province 528000China Arrhenius Laboratory Department of Materials and Environmental ChemistryStockholm University10691StockholmSweden

Ti-Ta alloys have been widely studied for biomedical applications due to their high biocompatibility and corrosion *** this work,nearly fully dense and in situ alloyed Ti-50 wt% Ta samples were fabricated by the laser powder bed fusion(LPBF) of mechanically mixed *** increased exposure time,and thereby increased laser energy density,insoluble Ta particles were almost dissolved,and a Ti-50 wt% Ta alloy was *** and dendritic structures were formed due to constitutional undercooling,which was caused by the high cooling rate of LPBF *** retained βphases and α " phases were observed in the LPBFed Ti-50 wt% Ta *** α" phase was found at the boundary of the cellular structures,where the tantalum content was not high enough to suppress the bcc lattice transition completely but could suppress the β phase→α’ phase transition.

关键词： alloy Microstructure corrosion

Global Tool Path Fairing Algorithm for Automated Fiber Placement

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第3期35卷 539-546页

作者： Wang Xianfeng Ye Ziheng Wang Ruozhou zhao cong R&D Center for Composites Industry Automation Nanjing University of Aeronautics and Astronautics

A global energy fairing method,applied to automated fiber placement(AFP)tool path,was *** main purpose was to improve the adaptability of AFP path towards part with sharp curvature variation as well as product *** relation between path geometric property and manufacturing property was discussed and a series of experiments were carried *** on cubic B-Spline global fairing method,the AFP tool path was faired which decreased the tool path curvature and curvature changing *** with initial ones,the path faired by the proposed method was relatively flat and smooth,which contributed to layup efficiency and reducing bulking *** method was demonstrated potentials in application for AFP manufacturing,especially for aeronautic and aerospace industry practice.

关键词： automated fiber placement(AFP) tool path fairing fiber steering manufacturing

Fiber-tip polymer clamped-beam probe for high-sensitivity nanoforce measurements

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Light(Science & Applications) 2021年第9期10卷 1768-1779页

作者： Mengqiang Zou Changrui Liao Shen Liu cong Xiong cong zhao Jinlai zhao Zongsong Gan Yanping Chen Kaiming Yang Dan Liu Ying Wang Yiping Wang Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education/GuangDong Province College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China Shenzhen Key Laboratory of Photonic Devices and Sensing Systems for Internet of Things Guangdong and Hong Kong Joint Research Centre for Optical Fibre SensorsShenzhen UniversityShenzhen518060China College of Materials Science and Engineering Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsShenzhen518060China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and Technology(HUST)Wuhan430074China Shenzhen Huazhong University of Science and Technology Research Institute ShenzhenGuangdong518057China

Micromanipulation and biological,material science,and medical applications often require to control or measure the forces asserted on small ***,we demonstrate for the first time the microprinting of a novel fiber-tip-polymer clamped-beam probe micro-force sensor for the examination of biological *** proposed sensor consists of two bases,a clamped beam,and a force-sensing probe,which were developed using a femtosecond-laser-induced two-photon polymerization(TPP)*** on the finite element method(FEM),the static performance of the structure was simulated to provide the basis for the structural design.A miniature all-fiber micro-force sensor of this type exhibited an ultrahigh force sensitivity of 1.51 nmμN−1,a detection limit of 54.9 nN,and an unambiguous sensor measurement range of~2.9 *** Young’s modulus of polydimethylsiloxane,a butterfly feeler,and human hair were successfully measured with the proposed *** the best of our knowledge,this fiber sensor has the smallest force-detection limit in direct contact mode reported to date,comparable to that of an atomic force microscope(AFM).This approach opens new avenues towards the realization of small-footprint AFMs that could be easily adapted for use in outside specialized *** such,we believe that this device will be beneficial for high-precision biomedical and material science examination,and the proposed fabrication method provides a new route for the next generation of research on complex fiber-integrated polymer devices.

关键词： fiber beam polymer

Tunable Lower Critical Solution Temperature of Poly(butyl acrylate)in Ionic Liquid Blends

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Chinese Journal of Polymer Science 2021年第5期39卷 585-591,I0006页

作者： Lie Chen Jin Huang cong zhao Jia-Jia Zhou Ming-Jie Liu Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China School of Physics Beihang UniversityBeijing 100191China International Research Institute for Multidisciplinary Science Beihang UniversityBeijing 100191China

We describe the lower critical solution temperature(LCST)-type phase behavior of poly(butyl acrylate)(PBA)dissolved in hydrophobic 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ionic liquids(ILs).The temperature-composition phase diagrams of these PBA/ILs systems are strongly asymmetric with the critical composition shifted to low concentrations of *** the molecular weight increases from 5.0×10^(3) to 2.0×10^(4),the critical temperature decreases by about 67℃,and the critical composition shifts to a lower ***,the LCST of PBA/ILs system increases as increasing the alkyl side chain length in the imidazolium *** IL blends as solvents,the LCST of PBA can be tuned almost linearly over a wide range by varying the mixing ratio of two ionic liquids without modifying the chemical structure of the polymers.

关键词： PBA Ionic liquid LCST Thermo-responsive

Coordinated Capacitor Voltage Balancing Method for Cascaded H-bridge Inverter with Supercapacitor and DC-DC Stage

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CES Transactions on Electrical Machines and Systems 2024年第2期8卷 191-201页

作者： Ye Zhang Zixin Li Fanqiang Gao cong zhao Yaohua Li IEEE Key Laboratory of High Density Electromagnetic Power and Systems(Chinese Academy of Sciences) Institute of Electrical EngineeringChinese Academy of SciencesHaidian District University of Chinese Academy of Sciences Shijingshan District

Cascaded H-bridge inverter(CHBI) with supercapacitors(SCs) and dc-dc stage shows significant promise for medium to high voltage energy storage applications. This paper investigates the voltage balance of capacitors within the CHBI, including both the dc-link capacitors and SCs. Balance control over the dc-link capacitor voltages is realized by the dcdc stage in each submodule(SM), while a hybrid modulation strategy(HMS) is implemented in the H-bridge to balance the SC voltages among the SMs. Meanwhile, the dc-link voltage fluctuations are analyzed under the HMS. A virtual voltage variable is introduced to coordinate the balancing of dc-link capacitor voltages and SC voltages. Compared to the balancing method that solely considers the SC voltages, the presented method reduces the dc-link voltage fluctuations without affecting the voltage balance of SCs. Finally, both simulation and experimental results verify the effectiveness of the presented method.

关键词： Cascaded H-bridge inverter(CHBI) Hybrid modulation strategy(HMS) Capacitor voltage balancing DClink voltage fluctuation Supercapacitor(SC)

Assessment of bearing performance degradation via extension and EEMD combined approach

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Journal of Central South University 2017年第5期24卷 1155-1163页

作者： LIU Yu-mei zhao cong-cong XIONG Ming-ye zhao Ying-hui QIAO Ning-guo TIAN Guang-dong Transportation College Jilin UniversityChangchun 130022China College of Engineering and Technology Jilin Agricultural UniversityChangchun 130118China University of Illinois at Urbana-Champaign IllinoisChampaign-Urbana 61801USA Engineering Department Changchun Visteon Faway Automotive Electronics Co.Ltd.Changchun 130011China

As a key component in rotating machinery, the operating reliability of bearing influences the performance and service life of the equipment directly. In order to describe bearing performance degradation(BPD) process effectively, an assessment approach combining extension and ensemble empirical mode decomposition(EEMD) was proposed. First, the extension was utilized to construct the matter-element of bearing operating state, and the energy moment of intrinsic mode functions(IMFs) was used as characteristic parameter of the matter-element. Then, to determine classical domains of characteristic parameters, the mathematical statistics method was adopted. Finally, the BPD was analyzed qualitatively and quantitatively according to the comprehensive correlation degree of bearing current operating state related to its healthy state. The analytic results of bearing test-rig show that the proposed method indicates the incipient fault approximately occurring in the 81 st hour, and the method also quantitatively presents the degree of BPD. By contrast, the BPD assessment based on time-domain features extraction method could not achieve the above two results effectively.

关键词： bearing performance degradation assessment extension ensemble empirical mode decomposition mathematical statistics

First total synthesis of (±)-abyssinoflavanone V

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Chinese Chemical Letters 2008年第6期19卷 658-660页

作者： Jin Hui Yang Yan Min zhao cong Bin Ji Key Laboratory of Energy Sources and Chemical Engineering of Ningxia Ningxia University Yinchuan 750021 China

The total synthesis of （±）-abyssinoflavanone V was first achieved through C-prenylation, selective protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap 4-hydroxybenzaldehyde and 2,4,6- trihydroxyacetophenone, with total yield 24%. All structures of new compounds were confirmed by IR, 1^H NMR and MS.

关键词： Abyssinoflavanone V Flavanone Isoprenylflavanoids Total synthesis

Combustion characteristics of Methanol-base fuel （MBF） made by coal

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Journal of Coal Science & Engineering(China) 2011年第4期17卷 431-433页

作者： ZHANG Quan zhao cong-cong LIU Yang School of Energy Science and Engineering Central South University Changsha 410083 China

Profound experimental research was made on Methanol-base fuel （MBF） mainly consisting of methanol, and the results were compared with that of diesel oil. Their respective combustion characteristics of caloric value, combustion efficiency and components of smoke were synthetically analyzed by employing the electronic weighing devices, the rotor flow-meter, intelligent flue gas analyzer, advanced bomb calorimeter, etc., referring to the feasibility of taking it as a fuel for general use. Experiment results show that Methanol-base fuel not only has superiorities on combustion characteristics but also bears energy saving and environmental protection advantages.

关键词： combustion characteristics methanol new energy low carbon

A review of tungsten fabricated via laser powder bed fusion

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Tungsten 2021年第2期3卷 218-233页

作者： Kai-Lun Li Jin-Han Chen cong-cong zhao Zhi-Jian Shen Wei Liu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Jihua Laboratory Foshan 528000China Arrhenius Laboratory Department of Materials and Environmental ChemistryStockholm University10691 StockholmSweden

Tungsten and its alloys with high strength,thermal conductivity,and plasma radiation resistance are highly desirable for applications in medical,electronic and also nuclear ***,the high melting point and high ductile–brittle transition temperature limit the fabrication of complex parts by using traditional methods,such as powder *** a kind of additive manufacturing technology,laser powder bed fusion(LPBF)was used to fabricate tungsten and its alloys in recent years because of its high energy density and low action *** paper reviewed the recent progress of LPBF fabricated *** main challenges,which are the lack of density and cracking problem,are *** methods to solve these problems are *** terms of improving the density,decreasing oxygen content,optimizing the process parameter,and adopting spherical powder were proved *** terms of cracking problem,the method of alloying,such as adding secondary phase nanoparticles and alloy elements,could significantly reduce the cracking ***,the crack problem has not been completely solved up to ***,future developments and potential new research directions for LPBF tungsten are proposed.

关键词： Tungsten Additive manufacturing Densification Cracking