2. Electron microscopy Transmission Electron microscopy (TEMs) Scanning Electron microscopy(SE 1) Transmission Electron microscopy(TEMs) 1931 Ruska 1939 Siemens commercialisation, 1945 used in cells, OSO4 1948 Peale baker bio-section
2. Electron microscopy Transmission Electron microscopy (TEMs) Scanning Electron microscopy (SE 1) Transmission Electron microscopy (TEMs) 1931 Ruska 1939 Siemens commercialisation, 1945 used in cells, OsO4 1948 Peale Baker bio-section
电子显微镜的基本构造 Cathode(tungsten Electron gun nside Wehnelt First condenser Condenser condenser ens system 俯米 室品料 Pro ector lens 回中 VIewing screen 窗题 Photographic plate Figure A-21 A Transmission Electron Microscope (in camera chamber (a) A photograph and (b) a schematic diagram of a TEM
电子显微镜的基本构造
*EM structure: EM consist largely of (1)Acylindrical column (a) Cathode, tungsten wire filament, a source of electron (b) Electromagnet lens, 1000-250,000X magnification (c) Screen, photographic plate, or film 2)Vacuum system (3) Electronically control console prowerful suppler 104-105V The formation of an image in the TEM depends on the differential scattering of electron by parts of the specimen The later is proportional to the amount of matter present in that part, that is its mass thickness, which is a measure of the number of atoms per unit area and their atomic density
*EM structure:EM consist largely of (1) A cylindrical column (a) Cathode, tungsten wire filament, a source of electron (b) Electromagnet lens, 1000-250,000 X magnification (c) Screen, photographic plate, or film (2) Vacuum system (3) Electronically control console prowerful suppler 104 -105V The formation of an image in the TEM depends on the differential scattering of electron by parts of the specimen. The later is proportional to the amount of matter present in that part, that is its mass thickness, which is a measure of the number of atoms per unit area and their atomic density
光源(电子枪) 聚光镜 样品 描线圈 物镜 样品 显像管 一照印 探头 可观察的像 荧光板上的像 光学显微镜 透射电镜 扫描电镜 光学显微镜和电子显微镜的简单原理示意图
光源 电子枪(阴极 阳极 聚光镜 粉()磁聚光 标本 标本 物镜 V磁物镜 囹中间镜 中间象 中间象 目镜 粉器磁投影德 终象(眼或底片) 荧光屏成象