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• 2018-11-27 12:36發(fā)布了問答

  求助：幫忙幫忙，機械英語NB的幫忙翻譯下

  The effect of beam diameter on the electron skirt in a high pressure scanning electron microscope R. Belkorissata， A. Kadouna， B. Khelifab， C. Mathieub，* aLaboratoire d’Elaboration et de Caracte′risation des Mate′riaux， Univ... The effect of beam diameter on the electron skirt in a high pressure scanning electron microscope R. Belkorissata， A. Kadouna， B. Khelifab， C. Mathieub，* aLaboratoire d’Elaboration et de Caracte′risation des Mate′riaux， Universite′ Djilali Liabe`s de Sidi Bel-Abbes， BP 89， 22000 Sidi Bel-Abbe`s， Algeria bCentre de Calcul et de Mode′lisation de Lens， University D’Artois， Faculte′ Jean Perrin， SP 18 Rue Jean Souvraz， 62307 Lens cedex， France Received 9 February 2004; accepted 19 March 2004 Abstract Helium gas and air are commonly used in the high pressure scanning electron microscope (HPSEM). The presence of a gaseous environment in the specimen chamber modifies the electron beam profile. In order to fully understand the beam-gas interaction， we have investigated the beam-diameter effect for two gases (helium and air) by Monte Carlo simulation. In this calculation， we have assumed that the electron beam is Gaussian and we have explored the influence of the nature of the gas at low voltage. When the beam diameter varies between 1 and 100 nm， there is no influence on the beam profile for these two gases. The resolving power of the HPSEM is not affected by the beamgas interaction. These theoretical results have been compared with experimental images obtained at low voltage under air and helium gases. The variation of image quality at low voltage has confirmed the interest of helium for use in a Field Emission Gun SEM (FEGSEM) in high pressure (or low vacuum) conditions. q 2004 Elsevier Ltd. All rights reserved. Keywords: High pressure scanning electron microscope; Monte Carlo; Electron scattering; Electron profile; Skirting 展開

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• 2018-11-21 22:44發(fā)布了問答

  X射線單晶體衍射儀的要求儀器

  　

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• 2016-05-31 11:15發(fā)布了問答

  電子探針能譜分析與能量色散型x射線熒光光譜分析有何異同

  　

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• 2015-04-15 04:57發(fā)布了問答

  這一份鑒定書，我想知道這個是真的嗎

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• 2013-03-13 08:33發(fā)布了問答

  請教高手這段話怎么翻譯

  Therefore， combining the results from the SEM， EDS， and XRD pattern， the phase composition of GWZM852 alloy could be inferred to include an a-Mg matrix and large block-shaped Mg12Zn(Y，Gd) phases distributed in a discontinuous network wi... Therefore， combining the results from the SEM， EDS， and XRD pattern， the phase composition of GWZM852 alloy could be inferred to include an a-Mg matrix and large block-shaped Mg12Zn(Y，Gd) phases distributed in a discontinuous network with some small block- and rod-shaped eutectic phases scattered at the edge of the Mg12Zn(Y， Gd) phases. 展開

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