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The modification behaviour for Si implanted PET

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Science China(Technological Sciences) 2003年第2期46卷 125-130页

作者：吴瑜光张通和刘安东张旭周固 key laboratory in University for Radiation beam technology & material modification Institute of Low Energy Nuclear Physics Beijing Normal University Beijing Radiation Center Testing and Analysis Center Beijing Normal University

Polyethylene terephthalate (PET) has been modified by Si ion implantationwith a dose ranging from 1 x10^(16) to 2x10^(17) ions /cm^2 using a metal vapor vacuum arc (MEVVA)source. The surface morphology was observed by atomic force microscopy (AFM). The change in themicro-structure of Si implanted PET was observed with a transmission electron microscope (TEM). Itis believed that the change would improve the conductive properties and wear resistance. Theelectrical properties of PET have been improved via Si ion implantation. The resistivity ofimplanted PET decreased obviously with an increase in ion dose. When Si ion dose was 2x10^(17)cm^(-2), the resistivity of PET could be less than 7.9 Ω ? m. The surface hardness andmodulus increased obviously. The mechanical property of the implanted PET has been modified *** hardness and modulus of Si implanted PET with a dose of 2 x 10^(17)/cm^2 are 12.5 and 2.45times greater than those of pristine PET, respectively. The area of cutting groove for Si implantedPET is narrower and shallower than those of the unimplanted PET. So the wear resistance is greatlyraised. In comparison with metal ion implantation, the improvement of mechanical properties isobvious in ion implantation into PET. Si ion beam modification mechanism of PET is discussed.

关键词： Si ion implantation, electrical property, hardness and modulus, modification mechanism of polymer.

Measurment of the energy spectrum of an electron beam extracted from an accelerator

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Chinese physics B 2014年第9期23卷 549-555页

作者：胡涛王乃彦 College of Nuclear Science and technology Beijing Normal University China Institute of Atomic Energy key laboratory of beam technology and material modification of Ministry of Education Beijing Normal University Beijing Radiation Center

The electron energy spectrum is one of the most important characteristics of an electron beam that is extracted from a linear accelerator. The most direct way to determine an electron spectrum would be to use a magnetic spectrometer and this method could also give results with high precision and effectiveness. In this article we describe our design of a new multi-layer absorption method, which is based on the depth-dose curves method that can be used in most irradiation accelerators, and adds the Monte Carlo simulation and iterative algorithm in order to reconstruct the electron energy spectrum. In this article the energy spectrum was measured using these two methods, and good results were acquired. These results could be crosschecked, which made the results more reliable.

关键词： electron accelerator electron spectrum magnetic spectrometer multi-layer absorption

Electron Acceleration During the Mode Transition from Laser Wakefield to Plasma Wakefield Acceleration with a Dense-Plasma Wall

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Plasma Science and technology 2013年第9期15卷 841-844页

作者：刘明萍刘三秋何俊刘杰 College of Information Engineering Nanchang University key laboratory of beam technology and materials modification of the Ministry of Education Beijing Normal University department of physics Nanchang University Institute of Applied physics and Computational Mathematics

The wake bubble expansion and contraction by adding a dense-plasma wall in the background plasma during the mode transition from laser wakefield to plasma wakefield accel- eration is investigated by particle-in-cell simulations. The electrons are injected continuously into the cavity until the lateral bubble size equals the inner diameter of the wall. The injected electron bunch from the laser wakefield acceleration （LWFA） scheme is quasi phase-stably accel- erated forward because of the longitudinal contraction of the bubble. After the laser pulse is depleted completely, the electron bunch generated from the LWFA scheme drives a plasma wake- field. The electrons remaining in the channel are trapped and accelerated by the plasma wakefield. Ultimately, two energetic electron bunches with a narrow energy spread and low emittance are obtained.

关键词： quasi phase-stable acceleration monoenergetic electron bunch dense-plasmawall

A New Method to Measure the Divergence of X-Ray beams from Capillaries

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Chinese physics Letters 2006年第4期23卷 794-796页

作者：林晓燕李玉德池济宏刘安东谈国太 key laboratory of beam technology and material modification of Minister of Education Beijing Normal University Beijing 100875 Institute of Low Energy Nuclear physics and Department of Material Science and Engineering Beijing Normal University Beijing 100875 Beijing Radiation Center Beijing Normal University Beijing 100875

A new method to measure the divergence of x-ray beams propagated out from several capillaries is introduced, This new method is based on Bragg＇s law and is proven efficiently by the experimental measurement with coll... 详细信息

关键词： XRF SPECTROMETER OPTICS LENS

Light tuning CO/H_(2)composition on Ag:Unraveling CO_(2)mass transfer and electron-phonon coupling in plasmon-enhanced electrocatalysis

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Nano Research 2025年第1期18卷 173-185页

作者： Rui Lin Dong Fan Luca MBerger Thomas Possmayer Yu Zhou Jiexin Zhu Xingbao Chen Wen Luo Lars Allmendinger Andreas Tittl Leonardo de Souza Menezes Guillaume Maurin Shihe Yang and Stefan AMaier Nanoinstitute Munich Faculty of PhysicsLudwig-Maximilians-Universität München80539 MunichGermany Institut Charles Gerhardt Montpellier UMR 5253 CNRS ENSCM UniversitéMontpellierPlace E.Bataillon34090 MontpellierFrance Guangdong Provincial key Lab of Nano-Micro material Research School of Advanced MaterialsPeking University Shenzhen Graduate SchoolShenzhen 518055China State key laboratory of Advanced technology for materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Faculty of Chemistry and Pharmacy Ludwig-Maximilians-Universität München81377 MunichGermany Departamento de Física Universidade Federal de Pernambuco50670-901 Recife-PEBrazil School of physics and Astronomy Monash University Clayton CampusMelbourneVictoria 3800Australia department of physics Imperial College LondonSW72AZ LondonUK

Plasmon-enhanced electrocatalysis(PEEC)is an emerging approach to mitigate CO_(2)*** mechanisms behind CO_(2)adsorption and reduction at the catalyst-electrolyte interface in PEEC still need to be further ***,we employ a well-defined Ag nanostructure to elucidate these pivotal *** shining light with wavelengths of 625,525,405 nm on Ag,an adjustable CO/H_(2)ratio from 35 to 1 can be *** reaction pathway changing under plasmonic excitation does not originate from the lowered CO_(2)mass transfer in the vicinity of Ag,as the electrochemical quartz crystal microbalance results unravel that a slightly elevated temperature in bulk electrolyte caused by light irradiation cannot weaken the CO_(2)adsorption at the Ag catalyst-electrolyte *** calculations reveal that optical excitation towards shorter wavelengths leads to a progressive lowered energy barrier for H_(2)formation together with an enhanced energy barrier for^(*)COOH *** thermodynamically suppressed,CO_(2)reduction can still be improved kinetically by optimizing the excitation wavelength and intensity,being accompanied with the enhanced *** absorption spectroscopy results further correlate the higher photocurrent with a prolonged electron-phonon coupling time,verifying that the improvement of CO_(2)reduction kinetics in PEEC can be realized by hot electron harnessing.

关键词： plasmonic catalysis photoelectrochemical CO_(2)reduction CO/H_(2)ratio hot electron generation electronphonon coupling thermal effect

Electron-Positron Pair Production in an Arbitrary Polarized Ultrastrong Laser Field

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Communications in Theoretical physics 2012年第12期58卷 863-871页

作者：何良勇谢柏松郭新恒王虹宇 key laboratory of beam technology and materials modification of the Ministry of Education Beijing Normal University College of Nuclear Science and technology Beijing Normal University department of physics Anshan Normal University

Electron-positron pair production in an arbitrary polarized ultrastrong laser field is investigated in the first order perturbation approximation in which the Volkov states are used for convenient calculation of scattering amplitude and cross section. It is found surprisingly that the optimal pair production depends strongly on the polarization. For some cases of field parameters, the optimal field is e11iptically polarized or evenly circularly polarized one, rather than the usual linear polarization as indicated by previous works interesting unexpected features are a/so discussed briefly. Some insights into pair generation are given and some

关键词： electron-positron pair production elliptically polarized field total cross section

Preparing Cu_2ZnSnS_4 films using the co-electrodeposition method with ionic liquids

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Chinese physics B 2012年第5期21卷 697-700页

作者：陈永生王英君李瑞谷锦华卢景霄杨仕娥 key laboratory of material physics Department of PhysicsZhengzhou University

Cu2ZnSnS4（CZTS） films are successfully prepared by co-electrodeposition in aqueous ionic solution and sulfurized in elemental sulfur vapor ambient at 400 C for 30 min using nitrogen as the protective *** is found that the CZTS film synthesized at Cu/（Zn＋Sn）=0.71 has a kesterite structure,a bandgap of about 1.51 eV,and an absorption coefficient of the order of 10 4 cm *** indicates that the co-electrodeposition method with aqueous ionic solution is a viable process for the growth of CZTS films for application in photovoltaic devices.

关键词： sulfurization Cu2ZnSnS4 co-electrodeposition

Structure and magnetic properties of Fe_(96-x)Zr_xB_4 nanowire arrays

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Science China(physics,Mechanics & Astronomy) 2013年第10期56卷 1840-1843页

作者： FU JunLi ZHU Min WANG WenZhong XUE DeSheng College of Science Minzu University of China key laboratory of beam technology and material modification of Ministry of Education Beijing Normal University key laboratory for Magnetism and Magnetic materials of the Ministry of Education Lanzhou University

Fe96-xZrxn4 （1〈x〈12） nanowires were prepared by electrodepositing into anodic aluminum oxide templates. The diameter of nanowires used is 100 nm and the aspect ratio is 75. The structure of the nanowire arrays was studied by selected area electron diffraction, X-ray diffraction and MOssbauer spectrometer. The phase structure of Fe96_xZrxB4 nanowires is changed from a crystalline phase to a homogenous amorphous phase with the increasing of Zr content. The Fe96_xZrxB4 nanowires are com- posed of a-Fe-like and Zr-rich FeZrB phases. With the increasing of Zr composition, the atoms of Fe site in both phases are more disorderly, and the ct-Fe-like phase decreasing with the FeZrB phase increasing. The anisotropy of Fe96_xZrxB4 nanowires becomes more obvious with the increasing of Zr content, and the easy magnetizing axis is parallel to the nanowire arrays.

关键词： Fe96-xZrxB4 nanowire phase structure M6ssbauer effect

Calculation of Electronic Structure of Anatase TiO_2 Doped with Transition Metal V,Cr,Fe and Cu Atoms by the Linearized Augmented Plane Wave Method

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Chinese Journal of Structural Chemistry 2009年第7期28卷 869-873页

作者：廖斌覃礼钊吴先映侯兴刚程肯刘安东 key laboratory of Ministry of Education of China for Radiation beam technology and material modification Institute of Low Energy Nuclear Physics Beijing Radiation Center Beijing Normal University Institute of physics and Electronic Science Tianjin Normal University department of material Science and Engineering Beijing Normal University

The electronic density of states and band structures of doped and un-doped anatase TiO2 were studied by the Linearized Augmented Plane Wave method based on the density functional theory. The calculation shows that the band structures of TiO2 crystals doped with transition metal atoms become narrower. Interesting, an excursion towards high energy level with increasing atomic number in the same element period could be observed after doping with transition metal atoms.

关键词： linearized augmented plane wave doped anatase Ti02 transition metal energy band