Abstract: Letting core-loss energy of an objective element be E.sub.c, and width of the energy selection slit be .DELTA.E. Initially, a pre-edge image obtained by increasing an acceleration voltage of an electron gun by E.sub.c -.DELTA.E and a pre-pre-edge image obtained by increasing an acceleration voltage by E.sub.c -.DELTA.E are taken with the same exposure time, and an intensity ratio R of the pre-edge image to the pre-pre-edge image is calculated. Next, a post-edge image obtained by increasing an acceleration voltage by E.sub.c is taken with an exposure time t.sub.pre, and a pre-edge image is taken with an exposure time R.times.t.sub.pre. An element distribution image of the objective element can be obtained by simply performing image subtraction of the pre-edge image from the post-edge image in a computer.

Abstract: An electron energy filter is structured by superposing a pair of yokes having electron beam passage holes and pole pieces on each side facing each other so as that the pole pieces are positioned facing each other with a certain space in between, and the electron energy filter is mounted in a transmission electron microscope to obtain a stable elemental mapping image.

Abstract: A transmission electron microscope system equipped with an energy filter and capable of displaying a two-dimensional distribution map of element of concern on a real time basis. A transmission electron microscope incorporating an energy filer is equipped with a television camera for recording two types of energy-loss images in separate frame memories, respectively. For effecting background processing for image data, intensity of an image to be stored in one frame memory is attenuated with a constant ratio by an intensity regulating mechanism. A signal indicative of difference between the image data stored in the respective frame memories is outputted to a monitor as a picture signal.

Abstract: An exhaust gas control system has a guiding pipe with a proximal inlet end for connecting to a distal end of an engine exhaust pipe. An expanding portion of the guiding pipe has a central rearward expanding cone and spiralling blades extending between the cone and the walls of the expanding portion. The expanding portion is followed by an axially decreasing chamber and then an axially increasing chamber to the distal opening. A duct is supported on radial vanes around the latter chambers. The duct has a forward opening slightly rearward of a maximum cross-sectional dimension of the guiding pipe and has an outlet positioned rearward of the distal opening of the guiding pipe.

Abstract: An exhaust gas control system has a proximal end for connection to a distal end of an exhaust pipe and has a first divergent and convergent and second divergent portions. Curved spiralling blades extend around inner walls of the first divergent and convergent portions leaving an open central space about which exhaust gas whirls. The second divergent portion exhausts the swirling gas through a distal opening. A duct surrounds the convergent and second divergent portions and controls flow of ambient air over those portions.