清华大学年电子显微分析期末考试试题.docVIP

清华大学2007年电子显微分析期末考试试题 ? 考试科目：电子显微分析 考试时间：?????2007年 试卷类型：? 本科期末? Examination of Electron Microscopy and Analysis (Jan. 2007) Question sheet A Department:???????????Name (in Chinese):??????????Student ID No.: ? Section I Section II Section III Total Score Section?I.?(20 marks. The answers should be written in English on?this?question sheet)?????????????????? 1.?There are two diffraction spots?G1?and G2?in?an electron diffraction pattern. The?excitation error (s) of?G1?is m and the?excitation error of?G2?is?2m?(m0). Which diffraction spot looks brighter,?G1?or?G2? (?????????)????????????(2 marks) 2. The thickness of a TEM specimen is usually thinner than 100nm. Write out two TEM specimen preparation methods that can make TEM specimen of ceramic samples with the required thickness. (??????????????????????????)?????????(2 marks) 3. You want to take an atomic resolution image of a specimen, but you do not want the image contrast to alter with a change in defocusing. Which technique should you use? (HRTEM,??HAADF, EF-TEM)?????????????????????????(2 marks) ?????????????????????????????????????????????? 4. O Ka?line is at 520eV and Cr La?is at 590eV. If you want to separate them using an X-ray analysis technique in SEM, which technique should you use???(?????). If you want to distinguish diamond from graphite using microanalysis technique in TEM, which technique should you use ? (??????) If you want to determine if a materials is polycrystalline or amorphous using TEM, which technique should you use?(??????????????????????????????)?????????(3 marks) ????????????????????????? 5. The side length of the CRT of a SEM is?100mm?and the scanning distance of the electron beam on an object in a specimen is?0.02mm. What is the real length of this object if the image of the object displayed on the CRT has a length of?5mm???(???????)??????????????????????????????????????????????????(3 marks)?????????? 6. The Kikuchi lines can be used for measuring a small tilting angle. If you ti