Jak robi an elektron mikroskop różni się od a światło mikroskop w pod względem zaobserwowanych?
Optical microscopes are very different from electron microscopes in that the light source is different, the lens is different, the imaging principle is different, the resolution is different, the depth of field is different, and the way of sample preparation is different. Optical microscope is commonly known as light microscope, is a kind of visible light as the illumination source of the microscope. Optical microscope is the use of optical principles, the human eye can not distinguish the tiny objects magnified imaging, for people to extract information on the microstructure of optical instruments. It is widely used in cell biology. Optical microscope generally consists of a stage, focusing illumination system, objective lens, eyepiece and focusing mechanism. The stage is used to hold the object to be observed. The focusing knob can be used to drive the focusing mechanism, so that the stage can be coarsely adjusted or fine-tuned to facilitate the clear image of the object under observation. The image of the optical microscope for the inverted image (up and down upside down, left and right interchangeable) electron microscope is the birth of high-end technology products, and we usually use the optical microscope has a similar place, but with the optical microscope is very different. First of all, optical microscope is the use of light source. The electron microscope is the use of electron beams, and the two can see the results of the difference, single and say that the magnification of the difference, such as observing a cell, the light microscope can only see the cell and part of the organelle, such as mitochondria and chloroplasts, but can only see the presence of its cells, can not see the specific structure of the organelle. An electron microscope, on the other hand, can see the fine structure of the organelles in more detail, and even large molecules like proteins. Electron microscope includes transmission electron microscope, scanning electron microscope, reflection electron microscope and emission electron microscope. Among them, scanning electron microscope is more widely used. Scanning electron microscope in the analysis of materials and research applications are very wide, mainly used in material fracture analysis, micro-area composition analysis, a variety of coating surface morphology analysis, layer thickness measurement and microstructure morphology and nano-materials analysis can also be combined with the X-ray diffractometer or electron spectrometer, constituting the electronic microprobe, used for the composition of the material analysis and so on. Scanning Electron Microscope, abbreviated as SEC, is a new type of electron optical instrument. It consists of a vacuum system, an electron beam system and an imaging system. It uses a finely focused beam of electrons to modulate the physical signals that are excited by scanning the surface of the sample. The incident electrons cause the sample surface to be excited with secondary electrons. It is these scattered electrons at each point that are observed by the microscope. The scintillation crystal placed next to the sample receives these secondary electrons, which are amplified to modulate the intensity of the electron beam of the CRT, changing the brightness on the CRT screen. The deflection coil of the CRT is synchronised with the electron beam on the surface of the sample, so that the CRT's fluorescent screen displays a topographical image of the sample surface. It has the characteristics of simple sample preparation, adjustable magnification, wide range, high resolution of the image, and large depth of field. Transmission electron microscope application performance:
1, crystal defect analysis. All the structures that destroy the normal array cycle are collectively called crystal defects, such as vacancies, dislocations, grain boundaries, precipitates and so on. These structures that destroy the periodicity of the dot matrix will lead to changes in the diffraction conditions of the region in which they are located, making the diffraction conditions of the region in which the defects are located different from the diffraction conditions of the normal region, which will show the corresponding difference between light and dark on the fluorescent screen.
2, tkanka analiza. W dodanie do rozmaych defektów może wytworzyć różne dyfrakcja wzory, przez które struktura i orientacja kryształu można być analizowane podczas obserwacji tkanki morfologii.
3,W situ obserwacja. Używanie odpowiednia próbka etap, in-situ eksperymenty można być przenoszone wynoszone w transmisja elektron mikroskop. dla przykładu, użycia odkształcenia rozciągania próbek obserwacji ich deformacji i złamania procesu.
4, wysoka rozdzielczość mikroskopia. Popraw rozdzielczość w kolejności do lepszej obserwacji mikrostruktury materiału został celu ludzi nieustannie dążenia. Wysoka rozdzielczość elektron mikroskopia używanie faza z elektron wiązka zmiany przez więcej dwa wiązki z spójne obrazowanie, w elektron mikroskop rozdzielczość jest wysokie wystarczające warunki, więcej elektron wiązki używane, wyższe rozdzielczość rozdzielczość z obrazu, nawet być używane używane być używane używane _ _ używane dla cienkie próbki atomowej struktury obrazowania.
