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Modification of polarization filtering technique in HF ground wave radar

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Journal of Systems Engineering and Electronics 2006年第4期17卷 737-742页

作者： Zhang Guoyi Tan Zhongji wang jiantao Aviation Univ. of Air Force Changchun 130022 P.R. China Beijing Inst. of Technology Beijing 100081 P.R. China.

The polarization filter using three orthogonal linear polarization antennas can suppress more disturbances than the polarization filter using two orthogonal linear polarization antennas in HF ground wave radar. But the algorithm of the threedimension filter is relatively complicated and not suitable for real-time processing. It can＇t use linear and nonlinear polarization vector translation technique directly. A modified polarization filter which is simple and has same suppressing ability as the three-dimension polarization filter is given. It only has half parameters of the primary one. Some problems about estimation of polarization parameters and selection of disturbances are discussed. A method of holding the phase of radar backscatter signal constantly is put forward so that unstationary disturbance signal can be processed.

关键词： radar engineering polarization filter interference suppression HF radar

Controlling and adjusting the concentration distribution during solidification process using static magnetic fields

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Journal of Materials Science & Technology 2020年第15期47卷 86-91页

作者： Pinfang Jiang jiantao wang Long Hou Yves Fautrelle Xi Li State Key Laboratory of Advanced Special Steels Shanghai UniversityShanghai200072PR China SIMAP-EPM-Madylam/G-INP/CNRS PHELMABP 7538402St Martin d'Heres CedexFrance

As concentration distribution changes have important effects on material structures and properties,controlling the concentration distribution is essential to alloy *** aim of the present work is to control and adjust the concentration distribution by the static magnetic *** is found that the magnetic field disperses grain boundary segregation and causes the uniform distribution of ***,by the three-dimensional computed tomography(3 D-CT) reconstruction,the flow distribution is seen and the effect mechanism of the magnetic field is *** present work may clarify the ambiguous understanding on the effect of the static magnetic field on solidification process.

关键词： Static magnetic feld Concentration distribution Structures

Surface Coating Enabling Sulfide Solid Electrolytes with Excellent Air Stability and Lithium Compatibility

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Energy & Environmental Materials 2024年第6期7卷 41-49页

作者： Min Luo Changhong wang Yi Duan Xuyang Zhao jiantao wang Xueliang Sun National Power Battery Innovation Center GRINM Group Corporation LimitedBeijing 100088China China Automotive Battery Research Institute Co. Ltd.Beijing 100088China General Research Institute for Nonferrous MetalsBeijing 100088China Eastern Institute for Advanced Study Eastern Institute of TechnologyNingbo 315200China

All-solid-state lithium metal batteries(ASSLMBs)featuring sulfide solid electrolytes(SEs)are recognized as the most promising next-generation energy storage technology because of their exceptional safety and much-improved energy ***,lithium dendrite growth in sulfide SEs and their poor air stability have posed significant obstacles to the advancement of sulfide-based ***,a thin layer(approximately 5 nm)of g-C_(3)N_(4)is coated on the surface of a sulfide SE(Li_(6)PS_(5)Cl),which not only lowers the electronic conductivity of Li_(6)PS_(5)Cl but also achieves remarkable interface stability by facilitating the in situ formation of ion-conductive Li3N at the Li/Li_(6)PS_(5)Cl ***,the g-C_(3)N_(4)coating on the surface can substantially reduce the formation of H_(2)S when Li_(6)PS_(5)Cl is exposed to humid *** a result,Li-Li symmetrical cells using g-C_(3)N_(4)-coated Li_(6)PS_(5)Cl stably cycle for 1000 h with a current density of 0.2 mA cm^(-2).ASSLMBs paired with LiNbO_(3)-coated LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)exhibit a capacity of 132.8 mAh g^(-1)at 0.1 C and a high-capacity retention of 99.1%after 200 ***,g-C_(3)N_(4)-coated Li_(6)PS_(5)Cl effectively mitigates the self-discharge behavior observed in *** surface-coating approach for sulfide solid electrolytes opens the door to the practical implementation of sulfide-based ASSLMBs.

关键词： anode interface g-C_(3)N_(4) coating Li_(6)PS_(5)Cl lithium dendrite inhibition solidstate lithium metal batteries

Recent progress on mechanisms,principles,and strategies for high-activity and high-stability non-PGM fuel cell catalyst design

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Carbon Energy 2024年第5期6卷 25-52页

作者： Yuping Yuan Yun Zheng Dan Luo Weibin Qiu jiantao wang Xin wang Zhongwei Chen GRINM(Guangdong)Institute of New Materials Technology FoshanChina Department of Chemical Engineering Waterloo Institute for NanotechnologyWaterloo Institute for Sustainable EnergyUniversity of WaterlooWaterlooOntarioCanada Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices School of Information and Optoelectronic Science and EngineeringSouth China Normal UniversityGuangdongChina National Power Battery Innovation Center GRINM Group Co.Ltd.BeijingChina

The commercialization of a polymer membrane H2-O2 fuel cell and its widespread use call for the development of cost-effective oxygen reduction reaction(ORR)nonplatinum group metal(NPGM)***,to meet the requests for the real-world fuel cell application and replacing platinum catalysts,it still needs to address some challenges for NPGM catalysts regarding the sluggish ORR kinetics in the cathode and their poor durability in acidic *** response to these issues,numerous efforts have been made to study NPGM catalysts both theoretically and experimentally,developed these into the atomically dispersed coordinated metal-nitrogen-carbon(M-N-C)form over the past *** this review,we present a comprehensive summary of recent advancements on NPGM catalysts with high activity and *** design strategies in terms of optimizing active-site density and enhancing catalyst stability against demetalization and carbon corrosion are *** is also emphasized the importance of understanding the mechanisms and principles behind those strategies through a combination of theoretical modeling and experimental ***,further understanding the mechanisms related to the active-site structure and the formation process of the single-atom active site under pyrolysis conditions is critical for active-site *** the active-site distance is the basic principle for improving catalyst activity through increasing the catalyst active-site *** studies for the catalyst deactivation mechanism and modeling stable active-site structures provide both mechanisms and principles to improve the NPGM catalyst ***,currently remained challenges and perspectives in the future on designing high-performance atomically dispersed NPGM catalysts toward fuel cell application are discussed.

关键词： batteries electrocatalysis energy storage and conversion fuel cells

Current Status and Future Directions in Environmental Stability of Sulfide Solid-State Electrolytes for All-Solid-State Batteries

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Energy Material Advances 2023年第1期4卷 130-143页

作者： Jianwen Liang Xiaona Li Changhong wang Jung Tae Kim Rong Yang jiantao wang Xueliang Sun Solid State Batteries Research Center GRINM(Guangdong)Institute for Advanced Materials and TechnologyFoshanGuangdong 528051China Department of Mechanical and Materials Engineering.University of Western Ontario LondonOntario N6A 5B9Canada China Automotive Battery Research Institute Co.Ltd.5th Floor No.43Mining Building North Sanhuan Middle RoadBeijing 100088China

Recently,sulfide-based solid-state electrolytes(SSEs)have attracted much attention owing to their high ionic conductivity and feasible mechanical *** environmental stability of sulfide-based SSEs is one of the critical aspects due to the possible decomposition,and ionic conductivity change will affect the fabrication and electrochemical performance of the ***,important efforts have been made to reveal and improve their environmental stability,and a timely summary of the progress is urgently *** this review,we first clarify the definition of environmental stability and its significance in the context of practical *** indicating the degradation mechanisms of sulfide-based SSEs,we summarize several effective strategies to improve their stability and also highlight the related theoretical *** stability of organic solvents of sulfide SSEs is also summarized and discussed,which may help reliable sulfide SSEs in the battery *** main target of this review is to gain insights and provide useful guidance to further improve the environmental stability of sulfide SSEs,which will finally promote the commercialization of sulfide-based all-solid-state batteries.

关键词： battery Solid sulfide

Ab initio Molecular Dynamics Study of Local Atomic Structure Evolution of U–Zr Alloy Melts upon Solidification

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Acta Metallurgica Sinica(English Letters) 2023年第9期36卷 1549-1558页

作者： Mingfeng Liu jiantao wang Yongpeng Shi Heyu Zhu Yan Sun Peitao Liu Xing-Qiu Chen Shenyang National Laboratory for Materials Sciences Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China

We study the local atomic structure evolution of UZr and UZr_(2) alloy melts upon solidification through ab initio molecular dynamics *** is achieved by analyzing in detail the temperature dependence of structure factors,pair correlation functions,the bond angle distributions,Honeycutt-Anderson index and Voronoi tessellation analysis as well as local bond orientation order *** observe that as the temperature decreases the pair correlation functions and structure factors become more structured with clear distinctions at the liquid–solid phase transition *** Honeycutt-Anderson indices and Voronoi tessellation analysis indicate that the liquid phase is predominantly comprised of the icosahedra-like local structures,whose fraction increases with decreasing temperature up to the transition temperature and then abruptly drops at the transition temperature,whereas the bcc-like local atomic structures dominate during the solidification ***,the bond orientation order analyses with\({\overline{w}}_{6}\)–\({\overline{q}}_{6}\)correlation map and bond angle distribution imply that the local structures mainly consist of the bcc-type during the solidification below the transition *** the analyses are consistent with each other,showing a first-order liquid to solid phase transition for both UZr and UZr_(2) solid solutions,which only differ in different predicted transition *** work provides a comprehensive insight into the detailed local structure evolution during the solidification of the U–Zr alloy melts at the atomic *** strategies used here can be extended to studying the liquid–solid phase transition in other alloy systems.

关键词： Local atomic structure Molecular dynamics Solidification U-Zr alloy melts

Nucleation kinetics of paramagnetic and diamagnetic metal melts under a high magnetic field

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Journal of Materials Science & Technology 2021年第14期73卷 165-170页

作者： Zhipeng Long Qiuyue Jiang jiantao wang Long Hou Xing Yu Yves Fautrelle Zhongming Ren Xi Li State Key Laboratory of Advanced Special Steels Shanghai UniversityShanghai200072China SIMAP-EPM-Madylam/G-INP/CNRS PHELMABP 75.38402St Martin d'Heres Cedex.France

The influence of a high magnetic field(HMF)on the nucleation kinetics of paramagnetic aluminum and diamagnetic zinc melts has been investigated by differential thermal analysis(DTA).It is found that the application of an HMF increases the undercooling of pure aluminum and pure zinc at the same heatingcooling ***,the quantitative analysis of activation energy calculated from the DTA results using the Kissinger method manifests that the HMF reduces the activation energy of pure aluminum and pure *** of magnetism,the nucleation frequency under an HMF is higher than that without an ***,the increase in undercooling under the HMF is mainly attributed to the increase of the contact angle,calculated by the functional relationship between the cooling rate and *** result is consistent with the increase of the calculated nucleation work for pure aluminum and pure ***,the increase in undercooling caused by the HMF is partly ascribed to the magnetic field-induced suppression of thermal convection in the undercooled melt.

关键词： Undercooling Activation energy Nucleation work High magnetic field

Catalytic removal of tert-butyldimethylsilyl (TBS) and tetrahydropyranyl (THP) groups from protected alcohols by NO^+BF_4^-in methanol

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Chinese Science Bulletin 2010年第25期55卷 2803-2806页

作者： wang jiantao WU WenTao XU YanFen WU LongMin State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 China

An effective, catalytic method has been developed to remove TBS and THP groups from protected alcohols. TBS and THP ethers were selectively cleaved using a catalytic amount of NO+BF4- (5 mol%) in methanol at room temp... 详细信息

关键词： TBS BF4 甲醇甲基硅烷催化净化 NO 保护吡喃

Segregation of Re at theγ/γ'boundary of Ni-based single crystal superalloys revealed by first-principles calculations based Monte-Carlo simulations

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Journal of Materials Science & Technology 2023年第12期143卷 54-61页

作者： Heyu Zhu jiantao wang Lei wang Yongpeng Shi Mingfeng Liu Jiangxu Li Yun Chen Yingche Ma Peitao Liu Xing-Qiu Chen 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 Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China CAS Key Laboratory of Nuclear Materials and Safety Assessment IMR(NMSA)Shenyang 110016China

Nickel-based single crystal superalloys have been widely used in aero-engines and gas turbine *** improve the creep resistance,rhenium is often added to the ***,it is not yet fully under-stood how the added Re elements distribute in the alloys and how the microstructure evolves with the addition of ***,we performed extensive first-principles calculations based Monte-Carlo simulated annealing of Ni-Al-Re ternary alloys with different Re concentrations ranging from 0.5 at.%to 6.0 at.%.The results demonstrate that with the decreasing temperature,most of Re atoms stay in theγphase,while a few of Re atoms stay in theγ'phase and tend to occupy the Al *** low temperatures,the Re atoms segregate at theγ/γ'boundary,in good agreement with *** find that the disorder-order transition temperature of the Ni-Al-Re ternary alloys increases with the Re concentration due to the Re-enhanced Al-Al ordering *** addition,we observe that at low temperatures the Re segregation at theγ/γ'boundary promotes the formation of Ni 4 Re-or Ni 8 Re-like local structures as the Re concentration is over 2 at.%.The formation of a large amount of these local structures consumes the Re atoms in solid solutions,and thus from the solid-solution strengthening point of view,this would have a negative influence on the creep resistance of the *** work provides important atomistic insights on the Re distribution and its effects on the stability of superalloys.

关键词： creep alloys resistance