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The rotation of polarization of a terahertz wave through subwavelength metallic structures

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Science China(Physics,Mechanics & Astronomy) 2013年第3期Mechanics & Astronomy) .卷 514-518页

作者： LIU JianFeng ZHOU QingLi shi yulei ZHANG CunLin Beijing Key Laboratory for Terahertz Spectroscopy and Imaging Key Laboratory of Terahertz OptoelectronicsMinistry of EducationDepartment of PhysicsCapital Normal University Beijing NO.55 Middle School

Structures consisting of a planar array of subwavelength metallic bars fabricated on a dielectric substrate are theoretically investigated in order to rotate the polarization of a normally incident terahertz wave in the resonance frequency *** attribute this phenomenon to one component of the terahertz electric field parallel to inclined metallic bars which is reflected strongly due to the terahertz re-radiation from accelerated electrons in the metallic bars,while the other component perpendicular to the bars transmits almost entirely through the *** theoretical analysis,we obtain the transmitted-terahertz components polarized in the x-and y-directions,*** studies indicate polarization of a terahertz wave can be rotated within two specific frequency bands when the terahertz impinges on the double-bar sample.

关键词： terahertz metamaterial polarization

Synthesis and Electrochemical Performance of Co3O4/Graphene

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Chemical Research in Chinese Universities 2014年第4期30卷 650-655页

作者： WANG Hongzhi shi yulei LI Zixuan ZHANG Weiguo YAO Suwei Department of Applied Chemistry School oJ Chemical Engineering and Technology Tianjin University Tianjin 300072 P. R. China

Co3O4/reduced graphene oxide composites were synthesized via a simple electrochemical method from graphene oxide and Co（NO3）2·6H2O as raw ***3O4 nanoparticles with sizes of around 30-50 nm were distributed on the surface of graphene nanosheets confirmed by scanning electron microscopy and transmission electron *** properties of Co3O4/graphene composite were tested by cyclic voltammetry,galvanostatic charge-discharge,and electrochemical impedance *** Co3O4/reduced graphene oxide composite was used as the pseudocapacitor electrode in the 2 mol/L NaOH aqueous electrolyte *** Co3O4/reduced graphene oxide composite electrode exhibited a specific capacitance of 357 F/g at a current density of 0.5 A/g in a three-electrode system.72％ of capacitance was retained when the current density increased to 3 A/*** Co3O4/reduced graphene oxide composite prepared electrodes show a high rate capability and excellent long-term *** 1000 cycles of charge and discharge,the capacitance is still maintained 87％ at a current density of 1 A/g,indicating that the composite is a oromising alternative electrode material used for supercapacitors.

关键词： Cobalt oxide Graphene Composite Electrochemical preparation Supercapacitor

Superatomic-based chirality:Asymmetric structures constructed by superatoms

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Aggregate 2024年第4期5卷 220-225页

作者： Famin Yu Rui Li Xinrui Yang yulei shi Zhigang Wang Institute of Atomic and Molecular Physics Jilin UniversityChangchunChina Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of PhysicsJilin UniversityChangchunChina Department of Physics Capital Normal UniversityBeijingChina

Chirality is one of the fundamental properties of molecules traditionally con-structed from ***,we report for theﬁrst time the successful construction of asymmetric chiral structures utilizing highly symmetric endohedral metallo-fullerene superatoms based on their own bonding ***ﬁcally,stable mirror-symmetric sinister and rectus structures are obtained by selecting a super-atom capable of forming four chemical bonds as the chiral *** analysis shows that the chiral vibration frequency of superatomic assemblies can be as low as a few wavenumbers,which greatly expands the range of chiral spectra com-pared to atom-based *** term this type of chirality based on superatoms as“superatomic-based chirality”.It is anticipated that this work will signiﬁcantly expand the variety of chiral structures at the atomic level.

关键词： assembly atomic level chirality superatom

Carrier dynamics and terahertz photoconductivity of doped silicon measured by femtosecond pump-terahertz probe spectroscopy

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Science China(Physics,Mechanics & Astronomy) 2009年第12期52卷 1944-1948页

作者： ZHOU QingLi shi yulei LI Tong JIN Bin ZHAO DongMei ZHANG CunLin Beijing Key Laboratory for Terahertz Spectroscopy and Imaging Key Laboratory of Terahertz OptoelectronicsMinistry of EducationDepartment of PhysicsCapital Normal UniversityBeijing 100048China Department of Electronics Engineering Tianjin University of Technology and EducationTianjin 300222China

The carrier dynamics and terahertz photoconductivity in the n-type silicon (n-Si) as well as in the p-type Silicon (p-Si) have been investigated by using femtosecond pump-terahertz probe technique. The measurements show that the relative change of terahertz transmission of p-Si at low pump power is slightly smaller than that of n-Si,due to the lower carrier density induced by the recombination of original holes in the p-type material and the photogenerated electrons. At high pump power,the bigger change of terahertz transmission of p-Si originates from the greater mobility of the carriers compared to n-Si. The transient photoconductivities are calculated and fit well with the Drude-Smith model,showing that the mobility of the photogenerated carriers decreases with the increasing pump power. The obtained results indicate that femtosecond pump-terahertz probe technique is a promising method to investigate the carrier dynamics of semiconductors.

关键词： semiconductor terahertz carrier dynamics

Understanding Bonding Nature of α-Keggin Polyoxometalates[XW_(12)O_(40)]^(n−)(X=Al,Si,P,S):A Generalized Superatomic Perspective

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Energy & Environmental Materials 2024年第6期7卷 176-183页

作者： Rui Li yulei shi Famin Yu Rui Wang Haitao Yan Boon K.Teo Zhigang Wang Department of Physics Capital Normal UniversityBeijing 100048China Key Laboratory of Material Simulation Methods&Software of Ministry of Education College of PhysicsJilin UniversityChangchun 130012China Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China State Key Laboratory for Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Institute of Theoretical Chemistry College of ChemistryJilin UniversityChangchun 130012China

α-Keggin polyoxometalates(POMs)[XW_(12)O_(40)]^(n−)(X=Al,Si,P,S)are widely used in batteries owing to their remarkable redox ***,the mechanism underlying the applications appears inconsistent with the widely accepted covalent bonding ***,first-principles calculations show that XW_(12)are core–shell structures composed of a shell and an XO_(4)^(n−)core,both are stabilized by covalent ***,owing to the presence of a substantial number of electrons in W_(12)O_(36)shell,the frontier molecular orbitals of XW_(12)are not only strongly delocalized but also exhibit superatomic properties with high-angular momentum electrons that do not conform to the Jellium *** analysis indicates that energetically high lying filled molecular orbitals(MOs)have reached unusually high-angular momentum characterized by quantum number K or higher,allowing for the accommodation of numerous *** attribute confers strong electron acceptor ability and redox activity to XW_(12).Moreover,electrons added to XW_(12)still occupy the K orbitals and will not cause rearrangement of the MOs,thereby maintaining the stability of these *** findings highlight the structure–activity relationship and provide a direction for tailor-made POMs with specific properties at atomic level.

关键词： first principles molecular orbital polyoxometalate redox activity superatom

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

Spectrum features of commercial derv fuel oils in the terahertz region

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Science China(Physics,Mechanics & Astronomy) 2012年第2期55卷 195-198页

作者： ZHAO Hui ZHAO Kun TIAN Lu ZHAO SongQing ZHOU QingLi shi yulei ZHAO DongMei ZHANG CunLin State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Laboratory of Optic Sensing and Detecting Technology College of ScienceChina University of PetroleumBeijing 102249China Beijing Key Laboratory for Terahertz Spectroscopy and Imaging Key Laboratory ofTerahertz OptoelectronicsMinistry of EducationDepartment of PhysicsCapital Normal UniversityBeijing 100048China International Center for Materials Physics Chinese Academy of SciencesShenyang 110016China

Characteristic spectra in the 0.5-2.5 terahertz (THz) range of three commercial derv fuel oils have been obtained using THz time-domain spectroscopy and calculated using density functional *** simulated results and experimental absorption curves suggest that the skeleton vibration is predominant in the THz region,and the absorption bumps of diesels are a superposition of various *** investigation demonstrates that different diesels can be distinguished using THz time-domain spectroscopy and THz technology is a promising method to detect the composition and properties of diesels via chemical analysis.

关键词： optical constants derv fuel oil time-domain analysis terahertz radiation

The rotation of polarization of a terahertz wave through subwavelength metallic structures

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Science China Chemistry 2013年第3期56卷 514-518页

作者： LIU JianFeng ZHOU QingLi shi yulei ZHANG CunLin Beijing Key Laboratory for Terahertz Spectroscopy and Imaging Key Laboratory of Terahertz Optoele's tronics Ministry of Educatio. Department of Physics Capital Normal University Beijing 100048 China Beijing N0.55 Middle School Beijing 100027 China

关键词： terahertz metamaterial polarization

Petroleum geological features and hydrocarbon enrichment of Linhe Depression in Hetao Basin, NW China

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Petroleum Exploration and Development 2023年第4期50卷 798-811页

作者： ZHANG Ruifeng HE Haiqing ZHU Qingzhong CHEN Shuguang LIU Xiheng DAN Weining HU Yanxu shi yulei ZHANG Yufei YU Haijun ZHANG Ximeng PetroChina Huabei Oilfield Company Renqiu 062552China PetroChina Oil&Gas and New Energy Company Beijing 100007China Logging Technology Research Institute of CNPC Logging Company Beijing 100007China No.2 Mud Logging Company CNPC Bohai Drilling Engineering Company LimitedRenqiu 062552China

Based on paleogeomorphology, drilling and seismic data, this paper systematically studies the structural and sedimentary evolution, source rock characteristics, reservoir characteristics and formation mechanism, hydrocarbon accumulation model and enrichment law in the Linhe Depression of the Hetao Basin, NW China. The Hetao Basin mainly experienced three stages of evolution, namely, weak extensional fault depression, strong extensional fault depression and strike-slip transformation, giving rise to four positive structural belts(Jilantai, Shabu, Nalinhu and Xinglong), which are favorable areas for oil and gas accumulation. The two main saline lacustrine source rocks, Lower Cretaceous Guyang Formation and Oligocene Linhe Formation, are characterized by high sulfur content, rich algae, early maturity, early expulsion, and wide oil generation window. The large structural transition belt in the intermountain area around the Hetao Basin controls the formation of large-scale braided river delta deposits, which are characterized by high quartz content(50%-76%), long-term shallow burial and weak compaction, low cement content, and good reservoir properties in delta front sandbody. The burial depth of the effective Paleogene reservoirs is predicted to reach 8000 m. Three hydrocarbon accumulation models, nose-uplift near sag, buried hill surrounding sag, fault nose near source rock, are constructed. The law of hydrocarbon accumulation in the Linhe Depression is finally clarified as follows: near-source around the depression is the foundation, high-quality thick reservoir is the premise, good tectonic setting and trap conditions are the key.

关键词： Hetao Basin Linhe Depression Cretaceous Guyang Formation Paleogene Linhe Formation Jilantai Oilfield Bayan Oilfield hydrocarbon enrichment law