Experimental Research Of DESI-MSI In Sequence Of Intersecting Lines

sequence of intersecting lines,that is,the order of ink formation at the intersection of seals and characters,and is a hot and difficult issue in the research and practice of forensic documents examination.The past and the present of methods of sequence of intersecting lines mainly about reducing layer,using the video spectral comparator,Raman spectrum imaging and so on,a variety of methods has its advantages and disadvantages and applicable scopes,at the same time,there are also many traditional methods are still unable to check the sequence of intersecting lines accurately,under this background,with the development and learning of natural science and interdisciplinary communication,scientific thinking and scientific methods used by many other disciplines have gradually entered the field of forensic documents examination,which makes many problems in the field of documents examination get new perspectives.In the aspect of sequence of intersecting lines,the Mass spectrometry imaging technique which is widely used in medicine,chemistry,biology and other disciplines,has been gradually used in checking the intersecting lines of stamp and ink,the principle can be applied to checking the sequence of intersecting lines,and in recent years,there are also some experts and scholars has been using this technique to test the sequence of intersecting lines or the sequence of ink,Some results can verify the feasibility of the method,but there are still few attempts to use this technique to test the sequence of intersecting lines,so this paper aims to provide more abundant experimental data and valuable results through experiments.There were attempts about spectrum imaging test of the color laser printing handwriting intersecting with the seal.But the spectrum imaging test of the black and white laser printing handwriting,ink jet printing handwriting,handwriting of different properties intersecting with the seal are still blank.So in this paper,according to use the DESI-MSI to test the above four types,and also use the microscope,the 3-d contour meter test comparing.The main content of this paper is divided into four parts.The first part is mainly an overview of the general situation of the sequence of intersecting lines,including the classification and key points of researching the sequence of intersecting lines,as well as common experimental methods of the sequence of intersecting lines.The second part mainly about handwriting formation and the overview of the stamp material,including the classification and characteristics of machine-mading letters(color laser printing letters,black and white laser printing letters)and handwriting letters(water-based pen writing,gel pen writing,oily pen writing),and the types and characteristics of common stamp materials.The third part mainly focus on the empirical research of sequence of intersecting lines inspection,including the microscope inspection method,three-dimensional profilometer inspection,DESI mass spectrometry imaging method,as well as the relevant experimental principles,experimental design,experimental process and experimental results.The fourth part is mainly about experimental summary and outlook.By comparing various experimental methods,and analyzing their data,and summarize the advantages and disadvantages of each method,to obtain the results.Meanwhile,analyzing the reasons that may affect the experimental results,and expecting more spectrometry imaging test of sequence of intersecting lines.