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Microstructural evolution and electromagnetic wave absorbing performance of single-source-precursor-synthesized SiCuCN-based ceramic nanocomposites

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Journal of Advanced Ceramics 2023年第7期12卷 1299-1316页

作者： jincan Yang Qingbo Wen bo Feng Yalei Wang Xiang xiong State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Fundamentals Department Air Force Engineering UniversityXi'an 710051China

Copper(Cu)-containing single-source precursors(SSPs)for the preparation of SiCuCN-based ceramic nanocomposites were successfully synthesized for the first time using polysilazane(PSZ),copper(II)acetate monohydrate(CuAc),and 2-aminoethanol via nucleophilic substitution reactions at silicon(Si)centers of *** synthesis process,polymer-to-ceramic transformation,and high-temperature microstructural evolution of the prepared ceramics were *** properties and electromagnetic wave(EMW)absorbing performance of the ceramics were investigated as *** results show that the polymer-to-ceramic transformation finishes at ca.900 ℃,and Cu nanoparticles are homogeneously distributed in a SiCN matrix,forming a SiCN/Cu *** annealing at 1200 ℃,the Cu nanoparticles completely transform into copper silicide(CusSi).Interestingly,the thermal stability of the Cu nanoparticles can be strongly improved by increasing the free carbon content,so that a part of metallic Cu nanoparticles can be detected in the ceramics annealed even at 1300 ℃,forming a SiCN/Cu/Cu_(3)Si/C *** with SiCN,the SiCuCN-based nanocomposites exhibit strongly enhanced dielectric properties,which results in outstanding EMW absorbing *** minimum reflection coefficient(RC_(min))of the SiCN/Cu/Cu_(3)Si/C nanocomposites annealed at 1300 ℃ achieves-59.85 dB with a sample thickness of 1.55 mm,and the effective absorption bandwidth(EAB)broadens to 5.55 GHz at 1.45 *** enhanced EMW absorbing performance can be attributed to an in situ formed unique network,which was constructed with Cu and Cu_(3)Si nanoparticles connected by ring-like carbon ribbons within the SiCN matrix.

关键词： polymer-derived ceramics(PDCs) dielectric property electromagnetic wave(EMW)absorbing copper(Cu) microstructure

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Thiazoloisoindigo-based Polymer Semiconductors: Synthesis,Structure-Property Relationship, Charge Carrier Polarity, and Field-Effect Transistor Performance

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Chinese Journal of Polymer Science 2024年第1期42卷 24-31,I0006页

作者： bo-Wen Li Miao xiong Mei-Hua Liu Zhi-Gao Li Long Sang Zi-Han xiong Biao Xiao Jian Pei Xiao-bo Wan Key Laboratory of Optoelectronic Chemical Materials and Devices Ministry of EducationSchoolofOptoelectronic Materials&TechnologyJianghan UniversityWuhan430056China Bejing National Laboratoryfor Molecular Sciences the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Developing new polymeric semiconductors with excellent device performance is essential for organic electronics. Herein, we synthesized two new thiazoloisoindigo(Tz II)-based polymers, namely, P(Tz II-d Th-d Th) and P(Tz II-d Th-d Tz), by copolymerizing thiophene-flanked Tz II with bithiophene and bithiazole, respectively. Owing to the more electron-deficient nature of bithiazole than bithiophene, P(Tz II-d Th-d Tz)possesses deeper LUMO/HOMO levels of-3.45/-5.47 e V than P(Tz II-d Th-d Th)(-3.34/-5.32 e V). The organic field-effect transistor(OFET) devices based on P(Tz II-d Th-d Th) exhibited p-type behaviors with an average hole mobility value as high as 1.43 cm^(2)·V^(-1)·s^(-1), while P(Tz II-d Th-d Tz)showed typical ambipolar characteristics with average hole and electron mobilities of 0.38 and 0.56 cm^(2)·V^(-1)·s^(-1). In addition, we compared the performances of both polymers with other Tz II-based polymers reported in our previous work, and showed that the charge carrier polarity can be manipulated by adjusting the number of the thiophene units between the acceptor unit. As the increase of the number of thiophene rings,charge carrier polarity shifts from electron-dominated ambipolar transport to hole-dominated ambipolar transport and then to unipolar hole transport in OFETs, which provides an effective molecular design strategy for further optimization of polymer OFET performance.

关键词： Field-effect transistor Charge carrier polarity Thiazoloisoindigo

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Microstructure and antibacterial property of stainless steel implanted by Cu ions

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中国有色金属学会会刊：英文版 2004年第z1期14卷 328-331页

作者： XU bo-fan NI Hong-wei xiong Ping-yuan xiong Juan DAN Zhi-gang School of Material and Metallurgy Wuhan University of Science and Technology Wuhan 430081 China School of Material and Metallurgy Wuhan University of Science and Technology Wuhan 430081 China School of Medicine Science Wuhan 430081 China School of Material and Metallurgy Wuhan University of Science and Technology Wuhan 430081 China School of Material and Metallurgy Wuhan University of Science and Technology Wuhan 430081 China

Copper ions were implanted into AISI 304 austenitic stainless steel by metal vapor vacuum are (MEVVA) with 60 - 100 keV energy and a dose range (0.2 - 5.0) × 1017 cm-2. Then Cu-implanted stainless steel was treated by a special antibacterial treatment. Antibacterial rates of Cu-implanted stainless steel, Cu-implanted stainless steel with special antibacterial treatment and un-implanted stainless steel were obtained by agar plate method. Phase composition in the implanted layer was analyzed by glancing X-ray diffraction (GXRD). Microstructure of antibacterial stainless steel was observed with transmission electron microscopy (TEM), and changes of the bacterium appearance after 24 h antibacterial action on the surface of un-implanted and Cu-implanted stainless steel with antibacterial treatment were observed with bio-TEM respectively. The results show that stainless steel obtains antibacterial property against E. coli when the Cu ions dose approaches to the saturated one. A suitable amount of Cu-rich phase uniformly disperses on the surface of Cu-implanted stainless steel that is treated by the special antibacterial treatment. The Cu-rich phase naked on the surface has a function of damage to pericellular membrane and cell wall,the pericellular membrane is thickened and the karyon degraded, and finally, bacteria die. Cu-rich phase naked on the surface endows stainless steel with best antibacterial property.

关键词： stainless steel copper ion implantation antibacterial property

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Modeling of Filling and Solidification Process for TiAl Exhaust Valves During Suction Casting

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Acta Metallurgica Sinica(English Letters) 2013年第1期26卷 33-48页

作者： Chao xiong Yingche MA bo CHEN Kui LIU Yiyi LI Institute of Metal Research Chinese Academy of Sciences

Investment and suction casting （ISC） represents an economic and promising process route to fabricate auto-motive exhaust valves of γ-TiAI based alloys, but information available on the metal flow and the temperature changeseduring mould filling and solidification process for the ISC process is meager. A sequentially coupled mathematical flow-thermal model, based on the commercial finite-volume/finite-difference code FLOW-3D and the finite-element code PROCAST, has been developed to investigate the ISC process. In term of calcu-lating the flow and temperature fields during the filling and solidification stages, potential defects including the gas bubbles and the surface air entrainment occurred in the mould filling process and the shrinkage porosities formed in the solidification process are predicted and the reasons for the formation of these defects are also analyzed. The effects of filling pressure difference control methods and moulds on gas bubble and surface air entrainment behavior are presented. It is found that by changing the filling pressure difference control methods from general suction casting to ＂air leakage＂ suction casting and reducing air leakage flow rates, the gas bubbles are eliminated effectively, and the surface air entrainment attenuate dramatically. With resort to a mould with a tetragonal runner, the surface air entrainment decrease to the lowest level. Finally, the water analogue and suction casting experiments of exhaust valves are implemented for further validation of the simulation results.

关键词： Filling and solidification γ-TiAI Exhaust valves Suction casting Simulation

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Development of readout electronics for bunch arrival-time monitor system at SXFEL

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Nuclear Science and Techniques 2019年第5期30卷 113-121页

作者： jin-Guo Wang bo Liu Shanghai Institute of Applied Physics Chinese Academy of Science University of the Chinese Academy of Science

A bunch arrival-time monitor(BAM) system,based on electro-optical intensity modulation scheme, is under study at Shanghai Soft X-ray Free Electron *** aim of the study is to achieve high-precision time measurement for minimizing bunch fluctuations. A readout electronics is developed to fulfill the requirements of the BAM system. The readout electronics is mainly composed of a signal conditioning circuit, field-programmable gate array(FPGA), mezzanine card(FMC150), and powerful FPGA carrier board. The signal conditioning circuit converts the laser pulses into electrical pulse signals using a photodiode. Thereafter, it performs splitting and low-noise amplification to achieve the best voltage sampling performance of the dual-channel analog-to-digital converter(ADC) in FMC150. The FMC150 ADC daughter card includes a 14-bit 250 Msps dual-channel high-speed ADC,a clock configuration, and a management module. The powerful FPGA carrier board is a commercial high-performance Xilinx Kintex-7 FPGA evaluation board. To achieve clock and data alignment for ADC data capture at a high sampling rate, we used ISERDES, IDELAY, and dedicated carry-in resources in the Kintex-7 FPGA. This paper presents a detailed development of the readout electronics in the BAM system and its performance.

关键词： Bunch arrival-time monitor (BAM) Shanghai Soft X-ray Free Electron Laser (SXFEL) Fieldprogrammable gate array (FPGA) Signal conditioning High-speed analog-to-digital converter (ADC)

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A novel electromagnetic induction detector with a coaxial coil for capillary electrophoresis

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Chinese Chemical Letters 2012年第2期23卷 201-204页

作者： jin xiong Qian Zuan Guang Chen School of Pharmaceutical Sciences Sun Yat-sen UniversityHigher Education Mega CentreGuangzhou 510006China

A novel electromagnetic induction detector with two inductors for CE was described *** two inductors were used as signal detection and reference,*** parameters affecting the detector performance（including coil turns,detection distance, excitation frequency,voltage,etc.） were *** the optimum condition,the feasibility of the detector was examined by analyzing inorganic *** fabricated detector showed good linear relationship between the response and the analytes concentrations,with a detection limit of 13μmol/L for Na~＋（S/N = 3）.A variety of advantages,such as simple construction, ease of operation,and considerably universal response,suggested this novel detector a promising application prospect in analytical area.

关键词： CE Electromagnetic induction detection MnCl_2 Coaxial coil

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Understanding Self-assembly,Colloidal Behavior and Rheological Properties of Graphene Derivatives for High-performance Supercapacitor Fabrication

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Chinese Journal of Polymer Science 2020年第5期38卷 423-434,I0005页

作者： Xia-Wei Yun bo Tang Zhi-Yuan xiong Xiao-Gong Wang Department of Chemical Engineering Laboratory of Advanced Materials(Ministry of Education)Tsinghua UniversityBeijing 100084China Department of Chemical and Bio-molecular Engineering The University of MelbourneMelbourneVictoria 3010Australia

Graphene derivatives,such as graphene oxide(GO)and reduced graphene oxide(RGO),have been widely used as promising two-dimensional nanoscale building blocks due to their fascinating properties,cost-effective production,and good *** the intrinsic self-assembling,colloidal,and rheological features of graphene derivatives is of critical importance to establish the formation-structure-property relationship of graphene-based *** article reviews recent progresses in our studies of these interesting properties of graphene derivatives for developing high performance *** content is organized to include characteristics of the dispersions of graphene derivatives,self-assembly of nanosheets from liquid medium,colloidal behavior,rheological properties of the dispersions,processing methods based on the properties,and performance of the fabricated *** and RGO nanosheets are proved to form different types of assembled structures with unique morphologies,such as ultrathin layer-by-layer films,porous aggregates,and *** unique rheological properties of GO dispersions and hydrogels,feasible for both the traditional wet-processing and newly-developed technology like three-dimensional printing,are highlighted for their potential in structural manipulation and scalable fabrication of graphene-based *** research devoted to up-grading the performance of supercapacitors is presented in some details,which could be applicable for fabricating other graphene-based energy storage *** challenges and perspectives in our point of view are given in the last part of this feature article.

关键词： Graphene derivatives Self-assembly Colloids Rheology Processing Supercapacitor

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Determinants of saturation magnetic flux density in Fe-based metallic glasses:insights from machine-learning models

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Rare Metals 2024年第10期43卷 5256-5267页

作者： Jie xiong bo-Wen Bai Hao-Ran Jiang Angeles Faus-Golfe Materials Genome Institute Shanghai UniversityShanghai 200444China Institute of Special Environments Physical Sciences Harbin Institute of TechnologyShenzhen 518055China Laboratoire de Physique des 2 Infinis Irene Joliot-Curie(IJCLab) CNRS-IN2P3Universite Paris-Saclay91405 OrsayFrance

Fe-based metallic glasses have garnered significant attention due to their low coercivity force and core *** the saturation magnetic flux density(Bs)of Fe-based metallic glasses is crucial for their industry *** work constructed a dataset comprising330 training data and 157 test *** support vector regression model surpassed the tree-based ensemble models in the test set and demonstrated comparable accuracy to the tree-based ensemble models in the training ***,we proposed an indicator for Bsbased on symbolic *** newly proposed indicator exhibits a Pearson correlation coefficient exceeding 0.92 with *** present work provides a simple and accurate formula for predicting the Bsof Fe-based amorphous alloys,demonstrating the effectiveness of machine learning approaches in discovering novel soft magnetic materials.

关键词： Saturation magnetic flux density Fe-based metallic glasses Machine learning Symbolic regression

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Mechanism of ferrite nucleation induced by Y_(2)O_(2)S inclusion in low carbon steel

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Journal of Iron and Steel Research International 2023年第6期30卷 1291-1299页

作者： Hai-hui Zhang Hui-hui xiong jing Qin Jian-bo Zhang Faculty of Materials Metallurgy and ChemistryJiangxi University of Science and TechnologyGanzhou 341000JiangxiChina National Rare Earth Functional Material Innovation Center Ganzhou 341000JiangxiChina

To reveal the mechanism of ferrite nucleation induced by Y_(2)O_(2)S inclusion in steel,the work of adhesion,interfacial energy,structure stability and electronic properties of Fe(111)/YY_(2)O_(2)S(001)interfaces with various terminations were first investigated using the first-principles ***,the steels with and without yttrium were prepared,while the rare earth yttrium-based inclusions in low carbon steel were characterized using an electron probe micro-analyzer,and the grain size of steel was analyzed using a scanning electron microscope with electron backscattered *** results show that the bonding strength of Fe/Y_(2)O_(2)S interfaces with S-and Y-terminations is stronger than that of the interface with *** Fe-hcp-S interfaces with S-termination have the highest work of adhesion(4.01 J/m2)and the lowest interface distance(1.323A).The Fe-hcp-S interface exhibits the highest stability,and its interfacial bonding force is mainly attributed to the strong hybridization of Fe-3d and S-2p orbitals in the energy range of-7.5-0 ***,the interfacial energy of Fe-hcp-S is substantially lower than those of the ferrite(s)/Fe(L)interface and the ferrite-austenite interface,suggesting that Y_(2)O_(2)S inclusions in steel can efficiently promote ferrite *** experimental observations demonstrate that the ferrite grain size of steel containing 0.03 wt.% Y is much more refined than that of the steel without yttrium,and the average grain size of steel with and without Y is 102 and 258μm,*** indicates that the results of our calculations match with experimental findings.

关键词： Ferrite nucleation Inclusion Interfacial energy First-principles calculation Refinement

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Topological holographic quench dynamics in a synthetic frequency dimension

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Light(Science & Applications) 2021年第11期10卷 2184-2194页

作者： Danying Yu bo Peng Xianfeng Chen xiong-Jun Liu Luqi Yuan State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong University200240ShanghaiChina Shanghai Research Center for Quantum Sciences 201315ShanghaiChina jinan Institute of Quantum Technology 250101JinanChina Collaborative Innovation Center of Light Manipulations and Applications Shandong Normal University250358JinanChina International Center for Quantum Materials and School of Physics Peking University100871BeijingChina Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology518055ShenzhenChina

The notion of topological phases extended to dynamical systems stimulates extensive studies,of which the characterization of nonequilibrium topological invariants is a central issue and usually necessitates the information of quantum dynamics in both the time and momentum ***,we propose the topological holographic quench dynamics in synthetic dimension,and also show it provides a highly efficient scheme to characterize photonic topological phases.A pseudospin model is constructed with ring resonators in a synthetic lattice formed by frequencies of light,and the quench dynamics is induced by initializing a trivial state,which evolves under a topological *** key prediction is that the complete topological information of the Hamiltonian is encoded in quench dynamics solely in the time dimension,and is further mapped to lower-dimensional space,manifesting the holographic features of the *** particular,two fundamental time scales emerge in the dynamical evolution,with one mimicking the topological band on the momentum dimension and the other characterizing the residue time evolution of the state after the *** this,a universal duality between the quench dynamics and the equilibrium topological phase of the spin model is obtained in the time dimension by extracting information from the field evolution dynamics in modulated ring systems in *** work also shows that the photonic synthetic frequency dimension provides an efficient and powerful way to explore the topological nonequilibrium dynamics.

关键词： dynamics dimension topological

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