Abstract: The present disclosure provides a method for extracting tar aroma components from a cigarette butt and use of the tar aroma components in a cigarette. The method includes the following steps: (1) adding the cigarette butt to an extraction solvent, and carrying out ultrasound-assisted extraction to obtain an extraction solution; (2) centrifuging the extraction solution, and carrying out vacuum distillation on the supernatant to obtain a concentrated extractum; and (3) carrying out molecular distillation on the concentrated extractum, and collecting a light fraction of the molecular distillation to obtain the tar aroma components. In the present disclosure, the cigarette butt is used as a raw material, through the ultrasound-assisted extraction and separation by the molecular distillation to extract the tar, harmful substances in the tar are removed, and the aroma components are retained.

Abstract: Disclosed is a cycloidal pinwheel pair with uniform contact and one-tooth difference, comprising a stator and a rotor. Each gear tooth profile of the rotor has a modified recess provided symmetrically on both sides; the starting point (A) of the modified recess on one side of the gear tooth profile is located between a first point and a second point determined by locations of two limit positions, the end point (B) of the modified recess on the same side of the gear tooth profile is located between a third point and a fourth point determined by locations of two limit positions. By adopting the present disclosure, the internal leakage formed between high and low pressure chambers is effectively avoided, thereby significantly improving the volume efficiency and mechanical efficiency. Meanwhile, the present disclosure is extremely simple in structure and can be molded by one-time grinding with better manufacturability.