Abstract: The present disclosure discloses a rolling ring shrink fitting tool for rotary equipment, including a lifting frame; a movement slot is formed in a bottom surface of a top of the lifting frame; an output end of a first motor is connected with a main gear; guide rollers are embedded in a lifting seat through bearings; shrink fitting plates are two semicircular structures; lifting lugs are welded on outer sides of the shrink fitting plates; tooth rings are arranged outside the shrink fitting plates; stop rods are fixed on inner walls of the tooth rings; supporting screw rods are embedded at sunken positions on inner walls of the shrink fitting plates through bearings.

Abstract: The present disclosure discloses a rolling ring shrink fitting tool for rotary equipment, including a lifting frame; a movement slot is formed in a bottom surface of a top of the lifting frame; an output end of a first motor is connected with a main gear; guide rollers are embedded in a lifting seat through bearings; shrink fitting plates are two semicircular structures; lifting lugs are welded on outer sides of the shrink fitting plates; tooth rings are arranged outside the shrink fitting plates; stop rods are fixed on inner walls of the tooth rings; supporting screw rods are embedded at sunken positions on inner walls of the shrink fitting plates through bearings.

Abstract: The invention provides compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein R1 is H, chlorine, or bromine; R2 is electron attractive groups selected from the group consisting of CF3, CN, fluorine, CH3SO3, CF3SO3, and NO2; R3 is linear or branched alkyl having 1 to 10 carbon atoms, linear or branched alkoxyalkyl having 2 to 10 carbon atoms, aliphatic alcohol having 1 to 10 carbon atoms, or cycloalkyl having 3 to 6 carbon atoms. The invention also relates to methods for preparing the said compounds and the composition comprising the same.

Abstract: The invention provides compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein R1 is H, chlorine, or bromine; R2 is electron attractive groups selected from the group consisting of CF3, CN, fluorine, CH3SO3, CF3SO3, and NO2; R3 is linear or branched alkyl having 1 to 10 carbon atoms, linear or branched alkoxyalkyl having 2 to 10 carbon atoms, aliphatic alcohol having 1 to 10 carbon atoms, or cycloalkyl having 3 to 6 carbon atoms. The invention also relates to methods for preparing the said compounds and the composition comprising the same. The compounds of the present invention have the effect of &bgr;2-receptor agonist and can be used for the treatment of asthma and bronchitis.