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Enhanced photocurrent and photoluminescence spectra in MoS2 under ionic liquid gating

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Nano Research 2014年第7期7卷 973-980页

作者： Zhen Li Shun-Wen Chang Chun-chung Chen Stephen b. Cronin Department of Electrical Engineering Department of Physics University of Southern California 3737 Watt Way PHE 624 Los Angeles CA 90089 USA

We report substantial improvements and modulation in the photocurrent （PC） and photoluminescence （PL） spectra of monolayer MoS2 recorded under electrostatic and ionic liquid gating conditions. The photocurrent and photo- luminescence spectra show good agreement with a dominant peak at 1.85 eV. The magnitude of the photoluminescence can be increased 300% by ionic liquid gating due to the passivation of surface states and trapped charges that act as recombination centers. The photocurrent also doubles when passivated by the ionic liquid. Interestingly, a significant shift of the PL peak position is observed under electrostatic （14 meV） and ionic liquid （30 meV） gating, as a result of passivation. The ionic liquid provides significant screening without any externally applied voltage, indicating that these surface recombination centers have net charge. The acute sensitivity of monolayer MoS2 to ionic liquid gating and passivation arises because of its high surface-to-volume ratio, which makes it especially sensitive to trapped charge and surface states. These results reveal that, in order for efficient optoelectronic devices to be made from monolayer MoS2, some passivation strategy must be employed to mitigate the issues associated with surface recombination.

关键词： ionic liquid dichalcogenide MoS2 photoluminescence photocurrent passivation

Piling up multidecker pyrgos[n]cages as antibacterial materials

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Science China Materials 2025年第01期 314-316页

作者： Miguel A.Liuzzi-Vaamonde Jackson b.Lancaster Samantha A.Mason yuanning Feng Department of Chemistry and biochemistry The University of Oklahoma

The development of antibiotics is regarded as one of the most significant scientific advances in modern medicine. before the commercialization of antibiotics, infectious diseases were catastrophic throughout history [1]. Penicillin was used to treat serious infections in the 1940s, but unfortunately, with the introduction of antibiotics came the emergence of antibiotic resistance [2,3]. Evolved and adapted methicillin-resistant Staphylococcus aureus (MRSA) strains are presently impacting community and healthcare systems across the globe [4].

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Unusually high corrosion resistance in Mo_(x)CrNiCo medium entropy alloy enhanced by acidity in aqueous solution

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Journal of Materials Science & Technology 2023年第8期139卷 59-68页

作者： S.Shuang G.J.Lyu D.chung X.Z.Wang X.Gao H.H.Mao W.P.Li Q.F.He b.S.Guo X.y.Zhong y.J.Wang y.yang Department of Mechanical Engineering College of EngineeringCity University of Hong KongKowloon TongKowloonHong KongChina State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 101408China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072China Unit of Structures Department of Materials Science and EngineeringKTHStockholm SE-10044Sweden Thermo-Calc Software Råsundav.18SolnaSE-16767Sweden Department of Materials Science and Engineering College of EngineeringCity University of Hong KongKowloon TongKowloonHong KongChina Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou 510632China Department of Advanced Design and System Engineering College of EngineeringCity University of Hong KongKowloon TongKowloonHong KongChina

High corrosion resistance of alloys is essential for their structural applications;however,most alloys suffer from degradation of their corrosion resistance with the increasing acidity of their ***,we developed a series of medium-entropy alloys(MEAs)in this work,which ex-hibit high strength,superior fracture toughness and ultra-high corrosion resistance,outperforming the variety of corrosion resistant alloys hitherto *** interestingly,our MEAs exhibit an unusual anti-corrosion behavior and their corrosion resistance increases with acidity in Cl−containing *** extensive thermodynamic calculations,density functional theory(DFT)simulations and experi-ments,we reveal that the unusual anti-corrosion behavior of our MEAs can be attributed to their surface chemical complexity,which facilitates the physio-chemical-absorption of H_(2)O and O_(2)and thus the rapid formation of metastable medium entropy passive films that contain the lowest amount of defects,as compared to the passive films on conventional alloys reported in the literature.

关键词： Corrosion Passivation Alloy design Multi-principal element alloys Medium-entropy alloys

Sol-Gel Preparation and Luminescence Properties of baMgAl_(10)O_(17):Eu^(2+) Phosphors

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Journal of Rare Earths 2006年第6期24卷 706-711页

作者： chung-Hsin Lu chung-Tao Chen baibaswata bhattacharjee Department of Chemical Engineering National Taiwan University TaipeiChina Department of Physics Ramananda CollegeBishnupur BankuraWest Bengal India722 122

The synthesis of baMgAl10O17： Eu^2＋（bAM） phosphors using the sol-gel method and their luminescence properties were reported. The blue-light emitting bAM was synthesized using citric acid and ethylene glycol as chelating materials. Emission of blue-light was obtained from these phosphors. The luminescent intensity increases as the temperature of heat treatment is increased, This study investigated the effects of the molar ratio of ethylene glycol to citric acid （Ф value）, with respect to the phase formation and luminescence properties of bAM. The variation of the Фvalue resulted in the change of the sol-gel reaction mechanism and the microstructures of the resultant powders. An increase in Фvalue leads to an increase in the rate of bAM phase formation. The photoluminescent intensity of the prepared phosphors increases with heating temperatures because of enhanced crystallization.

关键词： phosphors sol-gel synthesis luminescent properties rare earths

Quantum correlations and entanglement in coupled optomechanical resonators with photon hopping via Gaussian interferometric power analysis

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Chinese Physics b 2024年第5期33卷 204-211页

作者： y.Lahlou b.Maroufi M.Daoud LPHE-MS Department of PhysicsFaculty of SciencesMohammed V UniversityRabatMorocco LPMS Department of PhysicsFaculty of SciencesIbn Tofail UniversityKénitraMorocco

Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum ***,for quantum systems prepared in pure states,it is difficult to differentiate between quantum entanglement and quantum ***,this indistinguishability is no longer holds for mixed *** contribute to a better understanding of this differentiation,we have explored a simple model for both generating and measuring these quantum *** study concerns two macroscopic mechanical resonators placed in separate Fabry–Pérot cavities,coupled through the photon hopping *** system offers a comprehensively way to investigate and quantify quantum correlations beyond entanglement between these mechanical *** key ingredient in analyzing quantum correlation in this system is the global covariance *** forms the basis for computing two essential metrics:the logarithmic negativity(E_(N)^(m))and the Gaussian interferometric power(P_(G)^(m)).These metrics provide the tools to measure the degree of quantum entanglement and quantum correlations,*** study reveals that the Gaussian interferometric power(P_(G)^(m))proves to be a more suitable metric for characterizing quantum correlations among the mechanical modes in an optomechanical quantum system,particularly in scenarios featuring resilient photon hopping.

关键词： quantum correlations entanglement Gaussian interferometric power logarithmic negativity optomechanics photon hopping

Current Status in Layered Ternary Carbide Ti_3SiC_2,a Review

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Journal of Materials Science & Technology 2009年第1期25卷 1-38页

作者： H.b. Zhang y.W. bao y. C. Zhou Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

This article provides a review of current research activities that concentrate on Ti3SiC2. We begin with an overview of the crystal and electronic structures, which are the basis to understand this material. Followings are the synthetic strategies that have been exploited to achieve, and the formation mechanism of Ti3SiC2. Then we devote much attentions to the mechanical properties and oxidation/hot corrosion behaviors of Ti3SiC2 as well as some advances achieved recently. At the end of this paper, we elaborate on some new discoveries in the Ti3SiC2 system, and also give a brief discussion focused on the ＂microstructure -property＂ relationship.

关键词： Layered ternary ceramics Ti3SiC2 Mechanical properties Oxidation

Structural and mass transport properties of liquid ytterbium in the temperature range 1123 K–1473 K

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Chinese Physics b 2023年第6期32卷 481-488页

作者： D D Satikunvar N K bhatt b y Thakore Department of Physics Sardar Patel UniversityVallabh VidyanagarGujarat 388120India Department of Physics Maharaja Krishnakumarsinhji Bhavnagar UniversityBhavnagarGujarat 364001India

We have studied the structural and atomic transport properties of liquid f-shell yb in the temperature range 1123 K–1473 K. Pair interactions between atoms are derived using a local pseudopotential. The potential parameters are fitted to the phonon dispersion curve at room temperature. The local pseudopotential used in the present study is computationally more efficient with only three parameters, and it is found to be transferable to the liquid phase without changing the *** the various computed properties agree with reported theoretical and experimental findings, the adopted fitting scheme is justified. As a significant outcome of the study, we find that(i) the melting in yb is governed by the Lindemann's law,(ii)the mass transport mechanism obeys the Arrhenius law,(iii) the role of the three-particle correlation function in deriving the velocity autocorrelation function is small,(iv) the mean-square atomic displacement is more sensitive to the choice of interaction potential than the other bulk properties, and(v) liquid yb does not show liquid–liquid phase transition within the studied temperature range. Further, due to the good description of the structural and mass transport properties, we propose that yb remains divalent at reduced density.

关键词： transport properties pseudopotential single-particle dynamics ytterbium

AN HREM STUDy OF A LATERAL MICROCRACK bENEATHINDENTATION OF [001] SILICON

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Acta Metallurgica Sinica(English Letters) 1998年第5期11卷 342-346页

作者： y.Q.Wu X.y.yang y.b.Xu Inst of Metal Research The Chinese Acad of Sciences Shenyang China

A cross-sectional sample of indentation in [001] silicon was made and a lateral microcrack beneath the indentation was observed by high resolution electron microscope (HREM). The HREM images around the microcrack tip show an alternate distribution of the amorphous and lattice structure. The crack does not propagate by the successive debonding between certain atomic planes, meaning that before a crack completely opens, there may be a stage of amorphization, resulting from severe distortion of lattice.

关键词： amorphization lateal crack indentation HREM silicon

Numerical investigation of circle defining curve for two-dimensional problem with general boundaries using the scaled boundary finite element method

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Frontiers of Structural and Civil Engineering 2019年第1期13卷 92-102页

作者： chung Nguyen VAN Department of Civil Engineering Faculty of EngineeringChulalongkorn UniversityThailand Faculty of Civil Engineering Ho Chi Minh City of Technology and EducationVietNam

The scaled boundary finite element method (SbFEM)is applied to the static analysis of two dimensional elasticity problem,boundary value problems domain with the domain completely described by a circular defining curve. The scaled boundary finite element equations is formulated within a general framework integrating the influence of the distributed body force,general boundary conditions,and bounded and unbounded *** paper investigates the possibility of using exact geometry to form the exact description of the circular defining curve and the standard finite element shape function to approximate the defining *** linear elasticity problems are presented to verify the proposed method with the analytical *** examples show the accuracy and efficiency of the proposed method,and the performance is found to be better than using standard linear element for the approximation defining curve on the scaled boundary method.

关键词： exact geometry circular defining curve general boundaries SbFEM