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Different effects of Ce-doping on orbital and spin ordering in perovskite vanadate Sm_(1-χ)Ce_χ VO_3

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Chinese physics B 2013年第4期22卷 443-446页

作者：胡新波胡令罗轩赵邦传孙玉平 key laboratory of Materials physics Institute of Solid State Physics Chinese Academy of Sciences High Magnetic Field laboratory Chinese Academy of Sciences

The effects of Ce-doping on the phase transition of the orbital/spin ordering （OO/SO） are studied through the structural, magnetic, and electrical transport measurements of perovskite vanadate Sm1 x Ce x VO 3 . The measurements of structure show that the cell volume decreases as x≤ 0.05, and then increases as Ce-doping level increases further. The OO state exists but is suppressed progressively in the sample with x≤0.2 and disappears as x0.2. The temperature at which the C-type SO transition is present increases monotonically with Ce-doping level increasing. The temperature dependence of resistivity for each of the samples shows a semiconducting transport behavior and the transport can be well described by the thermal activation model. The activation energy first decreases as x ≤0.2, and then increases for further doping. The obtained results are discussed in terms of the mixed-valent state of the doped-Ce ions.

关键词： perovskite vanadate orbital/spin ordering electrical properties

Stability range of tilted dendritic arrays during directional solidification

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Science China(Technological Sciences) 2014年第12期57卷 2530-2535页

作者： XING Hui ZHAO Xiao Bin DUAN Pei Pei CHEN Chang Le CHEN Zhi JIN Ke Xin key laboratory of Space Applied physics and Chemistry Shaanxi Key Laboratory for Condensed Matter Structure and Properties Northwestern Polytechnical University

The stability range of primary spacing of the tilted dendritic arrays in directional solidification has been studied by quantitative phase-field simulations. Results show that both the real growth direction and morphological shapes of dendritic arrays change with the primary spacing for different misorientation angles(θ0). It has been found that the lower limit of primary spacing is independent of θ0, but the upper limit of primary spacing is strongly influenced by that. The two kinds of tertiary branching instabilities result in different behaviors of the variation of the upper limit with misorientation angle for different pulling velocities.

关键词： directional solidification stability range titled growth phase-field model

Kr L X-ray and Au M X-ray emission for 1.5 MeV–3.9 MeV Kr^(13+) ions impacting on an Au target

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Chinese physics B 2013年第10期22卷 257-261页

作者：梅策香张小安赵永涛周贤明任洁茹王兴雷瑜孙渊博程锐王瑜玉梁昌慧李耀宗肖国青 Department of Applied physics Xi'an Jiaotong University ion Beam & Optical Physical Joint laboratory of Xianyang Normal University and Institute of Modern physics Chinese Academy of Sciences Institute of Modern physics Chinese Academy of Sciences

Kr L X-ray and Au M X-ray emission for Kr13＋ ions with energies of 1.5 MeV and 3.9 MeV impacting on an Au target are investigated at heavy ion research facility in Lanzhou （HIRFL）. The L-shell X-ray yield per ion of Kr is measured as a function of incident energy. In addition, Kr L X-ray production cross section is extracted from the yield and compared with the result obtained from the classical binary-encounter approximation （BEA） model. Furthermore, the intensity ratio of the Au M/33 to Ma1 X-ray is investigated as a function of incident energy.

关键词： X-ray yield per ion X-ray production cross section intensity ratio

Fe_(0.8)CoSe_(2) nanosphere coated by N-doped carbon for ultra- high rate potassium selenium battery

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Rare Metals 2021年第9期40卷 2455-2463页

作者： Xin-Xin Jia Xin-Zhi Yu Bing-An Lu key laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial key laboratory of Low-Dimensional Structural physics and Devices School of Physics and ElectronicsHunan UniversityChangsha 410082China

Potassium-selenium(K-Se) batteries are a promising electrical energy storage candidate because of the cost-effectiveness and material sustainability, yet they suffer from shuttle effect, volume expansion and low powder density. The development of Se-based cathode is an effective way to overcome the above issues. Here we designed a hollow nano-spherical Co-Fe bi-metallic selenide coated with N-doped carbon(denoted as CFS@N-C)as cathode for K-Se batteries. Bimetallic selenide is benefit to improve the conductivity of composite materials;N-doped carbon layer encapsulation effectively inhibits the dissolution of poly-selenides and relieves the volume expansion. The as-prepared K-Se battery exhibits excellent rate performance(300 mAh·g^(-1) at 1000 mA·g^(-1)) and slowcharge/ultrafast-dischargecapability(dischargeat5000 mA·g^(-1) and charge at 100 mA·g^(-1) with ultrahigh capacity of 227 mAh·g^(-1)) with Coulombic efficiency nearly 100%. In addition, the ex-situ high-resolution transmission electron microscopy(HRTEM) images reveal that the charge–discharge mechanism of CFS@N-C is K^(+) replaces the bimetal and forms K_(2)Se. The unique design in this work may provide certain directions on researching for high power density K-storage materials.

关键词： Potassium selenium battery High powder density Excellent rate performance Inhibit shuttle effects Tolerate volume changes

Optical property and spectroscopy studies on the selected lubricating oil in the terahertz range

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Science China(physics,Mechanics & Astronomy) 2009年第12期52卷 1938-1943页

作者： TIAN Lu ZHOU QingLi JIN Bin ZHAO Kun ZHAO SongQing SHI YuLei ZHANG CunLin Department of Materials Science and Engineering China University of PetroleumBeijing 102249China Beijing key laboratory for Terahertz Spectroscopy and Imaging Key Laboratory of Terahertz OptoelectronicsMinistry of EducationDepartment of PhysicsCapital Normal UniversityBeijing 100048China State key laboratory of heavy Oil Processing China University of PetroleumBeijing 102249China Department of Mathematics and physics China University of PetroleumBeijing 102249China

The optical property and spectroscopy of selected kinds of lubricating oil are studied based on the terahertz time-domain spectroscopy (THz-TDS) in the spectral range of 0.3-1.6 THz. The samples are classified by their characteristics via the near-infrared spectrum. The experimental results reveal that lubricating oil is more sensitive in the range of terahertz than in the near-infrared,and the specific kinds of lubricating oil can be identified according to their different spectral features in the terahertz range. The THz-TDS technology applied to lubricating oil analysis has potentially significant impact on the petroleum field.

关键词： terahertz near-infrared transform spectrum lubricating oil

Multiple control of thermoelectric dual-function metamaterials

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International Journal of Mechanical System Dynamics 2023年第2期3卷 127-135页

作者： Pengfei Zhuang Jiping Huang Department of physics State Key Laboratory of Surface PhysicsKey Laboratory of Micro and Nano Photonic Structures(MOE)Fudan UniversityShanghaiChina

Thermal metamaterials based on transformation theory offer a practical design for controlling heat flow by engineering spatial distributions of material parameters,implementing interesting functions such as cloaking,concentrating,and ***,most existing designs are limited to serving a single target function within a given physical ***,we analytically prove the form invariance of thermoelectric(TE)governing equations,ensuring precise controls of the thermal flux and electric ***,we propose a dual‐function metamaterial that can concentrate(or cloak)and rotate the TE field *** addition,we introduce two practical control methods to realize corresponding functions:one is a temperature‐switching TE rotating concentrator cloak that can switch between cloaking and concentrating;the other is an electrically controlled TE rotating concentrator that can handle the temperature field precisely by adjusting external *** theoretical predictions and finite‐element simulations agree well with each *** work provides a unified framework for manipulating the direction and density of theTE field simultaneously and may contribute to the study of thermal management,such as thermal rectification and thermal diodes.

关键词： transformation thermotics thermoelectric effect dual-function thermal metamaterials thermal management

Evolution of Magnetic Domain Structure in a YIG Thin Film

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Chinese physics Letters 2016年第4期33卷 126-129页

作者：王然尚雅轩吴锐杨金波姬扬 State key laboratory for Superlattices and Microstructures Institute of SemiconductorsChinese Academy of Sciences State key laboratory for Mesoscopic physics School of PhysicsPeking University Collaborative Innovation Center of Quantum Matter

The evolution of a magnetic domain structure induced by temperature and magnetic field is reported in silicon- doped yttrium iron garnet （YIG） films with perpendicular anisotropy. During a cooling-down procedure from 300K to 7K, a 20% change in the domain width is observed, with the long tails of the stripes being shortened and the twisting stripes being straightened. Under the influence of the stray field of a barium ferrite, the garnet presents an interesting domain structure, which shows an appearance of branching protrusions. The intrinsic mechanisms in these two processes are also discussed.

关键词： of on YIG Evolution of Magnetic Domain Structure in a YIG Thin Film in

Pion Production in heavy-ion Collisions in the 1 A GeV Region

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Chinese physics Letters 2009年第6期26卷 91-94页

作者：冯兆庆靳根明 Institute of Modern physics Chinese Academy of Sciences Lanzhou 730000 Center of Theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000

Within the framework of the improved isospin dependent quantum molecular dynamics （ImIQMD） model, pion emission in heavy-ion collisions in the region 1 A GeV is investigated systematically, in which the pion is considered to be mainly produced by the decay of resonances △（1232） and N^＊（1440）. The in-medium dependence and Coulomb effects of pion production are included in the calculation. Total pion multiplicity and π^-/π^＋ yields are calculated for the reaction ^197Au＋^197Au in central collisions for selected Skyrme parameters SkP, SLy6, Ska, SⅢ and compared with the measured data of the FOPI collaboration.

关键词： gamma-ray bursts gamma-rays relativity

Ultrafast Photophysics of Star-Like Molecules with Benzene and Triazine Core

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Chinese physics Letters 2009年第12期26卷 236-239页

作者：冯文科孔胜肖立新蒙康王树峰龚旗煌 State key laboratory for Mesoscopic physics Department of Physics Peking University Beijing 100871

Static and transient spectroscopic characters of newly synthesized start-like molecules, 1,3,5-tri（10-butyl-3-propenyl-10H-phenothiazine）-benzene （TP3B） and 2,4,6-tri（10-butyl-3-propenyl -10H-phenothiazine）-[1,3,5]triazine （TP3T）, are studied using static, picosecond fluorescence and femtosecond transient absorption spectroscopy. The results show that when the benzene group is in the center, a large conjugation system is formed, while a fast electron-transfer process happens when the center group is triazine.

关键词： Chinese climate network complex systems small world community