電子衍射譜的計算機識別及未知晶體點陣測定.pdf

1、天津大學碩士學位論文電子衍射譜的計算機識別及未知晶體點陣測定姓名：梁柱申請學位級別：碩士專業(yè)：材料學指導教師：劉文西韓明2000.1.1ABSTRACTWiththedevelopmentofcomputertechnologythereisatendencyofcomputeraidedanalysisforalIkindsofinstrumentsAlthoughselectedareaelectrondiffractionisan

2、importantmethodforthemicroanalysisofthecrystaImaterials，selectedareaelectrondiffractionpaRerns(SAEDP)arestillmeasuredbyrulers1tiSnotonlyMeryinconvenientwhenrepeatedonmanydifferentpaRerns，butalsodifficultfortheanalysisoft

3、hemeasurementerrorByfarIittleworkcanbeenperformedoncomputeraidedanalysisofSAEDPsAprogramdevelopedinthispaperpresentsaunifiedapproachtoSAEDPcharacterizationandprocessingofpaRernsAnimagefileonSEADPscanbeacquiredbyascannerb

4、ywhichnegativefiImscanbescannedConsideringtheimagetreatmentspeedandmeasurementaccuracy800dpiresolutionfortheimagefileissuggestedinthepresentworkwhichenabletheminimumlengtherrortobesmallerthan003mmBecausethesizeoftheimage

5、fileisMerylargetheimagefilecann’tbetreateddirectlyAimagewithlowresolutionisgeneratedbyminifyingtheoriginalimagefilebyacertainscaleThisimageisusedtodeterminetheapproximateareaofeachdiffractionspotAndthentheseareaswillbema

6、ppedtotheoriginalimagefiletocalculatetheaccuratepositionofspotsSomeImagetreatmenttechniquessuchasedgedetectionandthresholdtreatmentareusedtoseparatethediffractionspotsfromthebackgroudoftheimageTheconstructionofthecharact

7、eristicparallelogramgridcannotonlyrefiecttheinherentcharacteristicparallelogramofSAEDP，butalsoexcludethenoiseandinterferentialspotsTheerrorcorrectionofthedataisbasedontheleastsquaresfittingmethodThemaximaIerrorbetweenthe

8、correctedcoordinateandtheactualcoordinateofthespotsjsusedtoevaluatethesuiteddegreeofthecharacteristicparallelogram1tcanbeprovedbysomeexperimentsthatthedatacalculatedbythecomputermeasureuptotherequirementoftheneededprecis