Abstract: The present invention relates to a SCR catalytic article, comprising —a substrate and —a copper-containing small pore zeolite, having a crystal structure characterized by a decrease of unit cell volume upon sulfurization and desulfurization of less than ?3 as determined by an X-ray powder diffraction, wherein the sulfurization and desulfurization are carried out in accordance with the processes as described in the specification, and to an exhaust treatment system comprising the same. The present invention also relates to a method for determining whether a metal-promoted small pore zeolite is resistant to irreversible sulfur poisoning and a method for evaluating whether a metal-promoted small pore zeolite is qualified for resistance to irreversible sulfur poisoning.

Abstract: A polishing tool includes a tool body and a polishing member which is mounted rotatably on the tool body and which has a central hole unit formed through the polishing member. The working surface of the polishing member has a plurality radially extending slots which are spaced apart from each other in an angularly equidistant relation and which extend from the inner periphery of the working surface to the outer periphery of the working surface. A plurality of flat working surface sections are defined on the working surface of the polishing member by the slots. When a slurry consisting of a lubricating liquid and abrasive grains flows onto the working surface of the polishing member via the central hole unit and when the polishing member is rotated on the tool body, each of the abrasive grains moves across all of the slots and from the inner periphery of the working surface to the outer periphery of the working surface, by hydrodynamic effect, so as to polish positively and effectively the workpiece.