A transmission electron microscope (TEM) projects an accelerated and focused electron beam onto a very thin sample. The electrons collide with the atoms in the sample, changing direction and producing solid-angle scattering. The scattering angle varies with the sample's density and thickness, resulting in an image with different brightness levels. This image, after magnification and focusing, is displayed on imaging devices such as a fluorescent screen, film, or a charge-coupled device (CCD). Application Areas：Transmission electron microscopy (TEM) has extensive applications in the life sciences, including ultra-high resolution imaging of cells and tissues, pathogen detection and diagnosis, imaging and analysis of biomolecules, nanotechnology research and applications, neuroscience research, and studies in histology and pathology.