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Impact of Surface Passivation on the Electronic Structure and Optical Properties of the Si1-xGex Nanowires

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Chinese Physics Letters 2015年第2期32卷 119-122页

作者：赖信张析张依兮向钢 College of Physical Science and Technology Sichuan University Key Laboratory of high energy density Physics and Technology of Ministry of Education Sichuan University

The electronic structures and optical properties of the [llO]-oriented Sil-xGex nanowires （NWs） passivated with different functional groups （-H, -F and-OH） are investigated by using first-principles calculations. The results show that surface passivation influences the characteristics of electronic band structures significantly： the band gap widths and types （direct or indirect） of the Si1-xGe, NWs with different terminators show complex and robust variations, and the effective masses of the electrons in the NWs can be modulated dramatically by the terminators. The study of optical absorption shows that the main peaks of the parallel polarization component of Si1-x Gex NWs passivated with the functional groups exhibit prominent changes both in height and position, and are red-shifted with respect to those of corresponding pure Si NWs, indicating the importance of both the terminators and Ge concentrations. Our results demonstrate that the electronic and optical properties of Si1-xGex NWs can be tuned by utilizing selected functional groups as well as particular Ge concentrations for customizing purposes.

关键词： 110 OH x)Ge_x Nanowires Impact of Surface Passivation on the Electronic Structure and Optical Properties of the Si Ge

Uniaxial strain-dependent magnetic and electronic properties of (Ga,Mn)As nanowires

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Chinese Physics B 2014年第9期23卷 306-309页

作者：张晨辉向钢兰木张析 College of Physical Science and Technology Sichuan University Key Laboratory of high energy density Physics and Technology of Ministry of Education Sichuan University

Variations in magnetic and electronic properties as a function of uniaxial strain in wurtzite （Ga,Mn）As nanowires （NWs） grown along the [0001] direction were investigated based on density functional theory （DFT）. We found that （Ga,Mn）As NWs are half-metal, and the ferromagnetic state is their stable ground state. The magnetism of the NWs is significantly affected by the strain and by the substituent position of Mn impurities. By examining charge densities near the Fermi level, we found that strain can regulate the conductive region of the N-Ws. More interestingly, the size of spin-down band gap of the NWs is tunable by adjusting uniaxial stress, and the NWs can be converted from indirect to direct band gap under tension.

关键词： dilute magnetic semiconductors (Ga,Mn)As nanowire strain

The enhanced element enrichment in the supercritical states of granite–pegmatite systems

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Acta Geochimica 2019年第3期38卷 335-349页

作者： Rainer Thomas Paul Davidson Karen Appel Section 3.6.Chemistry and Physics of Earth Materials Helmholtz-Centre Potsdam German Research Centre for Geoscience – GFZ CODES Centre for Ore Deposit and Earth Sciences School of Natural Sciences University of Tasmania high energy density scientific instrument European X-Ray Free-Electron Laser Facility GmbH

In this paper, we show that supercritical fluids have a greater significance in the generation of pegmatites,and for ore-forming processes related to granites than is usually assumed. We show that the supercritical melt or fluid is a silicate phase in which volatiles; principally H_2O are completely miscible in all proportions at magmatic temperatures and pressures. This phase evolves from felsic melts and changes into hydrothermal fluids, and its unique properties are particularly important in sequestering and concentrating low abundance elements, such as metals. In our past research, we have focused on processes observed at upper crustal levels, however extensive work by us and other researchers have demonstrated that supercritical melt/fluids should be abundant in melting zones at deep-crustal levels too. We propose that these fluids may provide a connecting link between lower and upper crustal magmas,and a highly efficient transport mechanism for usually melt incompatible elements. In this paper, we explore the unique features of this fluid which allow the partitioning of variouselements and compounds, potentially up to extreme levels,and may explain various features both of mineralization and the magmas that produced them.

关键词： Granites Pegmatites Supercritical state Extreme element enrichment

Electrochemical conversion of methane to bridge the gap in the artificial carbon cycle

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Journal of energy Chemistry 2025年第1期100卷 286-308页

作者： Yuhao Peng Yuefeng Song Ihar Razanau Juanxiu Xiao Wei Xiao Di Hu Guoxiong Wang College of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Dalian Institute of Chemical Physics Chinese Academy of Sciences Laboratory of Physical-Chemical Technologies SSPA Scientific and Practical Materials Research Centre of NAS of Belarus State Key Laboratory of Marine Resources Utilization in South China Sea Collaborative Innovation Center of Marine Science and Technology School of Marine Science and Engineering Hainan University Department of Chemical and Environmental Engineering University of Nottingham Ningbo China

Methane, an abundant one-carbon（C1） resource, is extensively used in the industrial production of vital fuels and value-added chemicals. However, current industrial methane conversion technologies are energy-and carbon-intensive, mainly due to the high activation energy required to break the inert C–H bond, low selectivity, and problematic side reactions, including CO2emissions and coke deposition. Electrochemical conversion of methane（ECM） using intermittent renewable energy offers an attractive solution, due to its modular reactor design and operational flexibility across a broad spectrum of temperatures and pressures. This review emphasizes conversion pathways of methane in various reaction systems, highlighting the significance and advantages of ECM in facilitating a sustainable artificial carbon cycle. This work provides a comprehensive overview of conventional methane activation mechanisms and delineates the complete pathways of methane conversion in electrolysis contexts. Based on surface/interface chemistry, this work systematically analyzes proposed reaction pathways and corresponding strategies to enhance ECM efficiency towards various target products, including syngas, hydrocarbons, oxygenates, and advanced carbon materials. The discussion also encompasses opportunities and challenges for the ECM process, including insights into ECM pathways, rational electrocatalyst design, establishment of benchmarking protocols, electrolyte engineering, enhancement of CH4conversion rates, and minimization of CO2emission.

关键词： Methane Electrochemical conversion Reaction mechanism Catalyst design Electrode Electrocatalysis

Study of the THGEM detector with a reflective CsI photocathode

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Chinese Physics C 2011年第4期35卷 363-367页

作者：刘宏邦郑阳恒谢一冈吕军光周莉俞伯祥章爱武安正华谢宇广张东郑志鹏 Graduate University of Chinese Academy of Sciences Guangxi University Institute of high energy Physics Chinese Academy of Sciences Beijing Nuclear instrument Factory

The THGEM detector without and with a CsI has been tested successfully. The optimal parameters of THGEM have been determined from eight samples. The UV photoelectric effect of the CsI photocathode is observed. The changing tendency related to the extraction efficiency （εextr） versus the extraction electric field is measured, and several electric fields influencing the anode current are adjusted to adapt to the THGEM detector with a reflective CsI photocathode.

关键词： THGEM CsI photocathode UV

Atomic structure and transition properties of H-like Al in hot and dense plasmas

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Chinese Physics B 2017年第1期26卷 160-169页

作者： Xiang-Fu Li Gang Jiang Hong-Bin Wang Qian Sun Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China College of Electrical Engineering Longdong University Qingyang 745000 China The Key Laboratory of high energy density Physics and Technology of Ministry of Education Chengdu 610065 China

The atomic structure and transition properties of H-like Al embedded in hot and dense plasmas are investigated using modified GRASP2 K code. The plasma screening effect on the nucleus is described using the self-consistent field ion sphere model. The effective nuclear potential decreases much more quickly with increasing average free electron density,but increases slightly with increasing electron temperature. The variations of the transition energies, transition probabilities,and oscillator strengths with the free electron density and electron temperature are the same as that of the effective nuclear potential. The results reported in this work agree well with other available theoretical results and are useful for plasma diagnostics.

关键词： H-like Al strongly-coupled plasmas atomic structure transition properties

IDENTIFICATION OF MARINE AEROSOL COMPONENT BY COMBINED NAA AND SCANNING ELECTRON MICROSCOPY WITH X—RAY ANALYSIS

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Nuclear Science and Techniques 1992年第3期3卷 205-209页

作者：杨绍晋章一鸣 Institute of high energy Physics Academia Sinica Beijing 100080 China scientific instrument Factory Academia Sinica. Beijing 100080. China

The concentrations of 30 elements in aerosol particles collected in western Pacific ocean have been determined by INAA. The crustal element concentrations decrease with increasing distance from land over the remote area close to Asia land and fluctuate around its average value over the remote ocean area. The volatile elements exhibite average atmospheric concentrations that are higher than those expected from the flux of seasalt or the continental dust. In order to identify marine aerosol component originating from the continent or ocean, the aerosol particles are examined by scanning electron microscopy combined with energy dispersive X-ray spectroscopy. Particle phase structure shows that the crustal aerosol particles are not present internal mixtures with seasalt aerosol, and it also proves the long-range transport of crustal elements from continent to ocean.

关键词： Aerosol Scanning electron microscopy INAA EDS

Significance of absolute energy scale for physics at BESⅢ

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Chinese Physics C 2008年第10期32卷 776-780页

作者：傅成栋莫晓虎 Institute of high energy Physics CAS

The effects of absolute energy calibration on BESⅢ physics are discussed in detail, which mainly involve the effects on τ mass measurement, cross section scan measurement, and generic error determination in other me... 详细信息

关键词： absolute energy calibration τ mass cross section scan error estimation

Kinematics of τ two-body decay near τ threshold at BESⅢ

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Chinese Physics C 2010年第11期34卷 1671-1679页

作者：莫晓虎 Institute of high energy Physics CAS

The kinematic properties of two-body decay near τ threshold are studied according to the special capacity of the BEPC accelerator and the BESⅢ *** presented are the transformations of energy and momentum of hadronic particles between different reference frames,and the corresponding distributions.A brand new method is proposed to obtain the energy spread of the accelerator by fitting the energy distribution of hadron from τ semi-leptonic decays.

关键词： kinematics τ threshold energy distribution energy spread