Abstract: A substituted pyrazolo[1,5-alpyrimidin-7-amine derivative, the structure of which is represented by formula (1), or pharmaceutically acceptable salts, solvates, stereoisomers, prodrugs, drug compositions thereof. The derivative has significant CDK9-selective inhibitory activity.

Abstract: A leaf spring for coupling a heat sink to an integrated circuit includes a central portion that has an aperture; a first spring arm that is formed on a first side of the central portion and includes a first through-hole for a first fastener; a second spring arm that is formed on a second side of the central portion and includes a second through-hole for a second fastener; a first bending axis that passes through the first side and is substantially perpendicular to a longitudinal axis of the leaf spring that passes through the first through-hole and the second through-hole; and a second bending axis that passes through the second side and is substantially perpendicular to the longitudinal axis of the leaf spring.

Abstract: The present disclosure provides a mixing circuit with high harmonic suppression ratio, including: a multi-phase generation module, which receives a first input signal and generates eight first square wave signals with a phase difference of 45°; a quadrature phase generation module, which receives a second input signal and generates four second square wave signals with a phase difference of 90°; a harmonic suppression module, connected with an output end of the quadrature phase generation module to filter out higher order harmonic components in the second square wave signals; and a mixing module, connected with output ends of the multi-phase generation module and the harmonic suppression module to mix output signals of the multi-phase generation module and the harmonic suppression module. The mixing circuit with high harmonic suppression ratio adds a harmonic suppression module on the basis of multi-phase mixing, thereby improving the harmonic suppression ratio of the output signal.

Abstract: The present disclosure provides a mixing circuit with high harmonic suppression ratio, including: a multi-phase generation module, which receives a first input signal and generates eight first square wave signals with a phase difference of 45°; a quadrature phase generation module, which receives a second input signal and generates four second square wave signals with a phase difference of 90°; a harmonic suppression module, connected with an output end of the quadrature phase generation module to filter out higher order harmonic components in the second square wave signals; and a mixing module, connected with output ends of the multi-phase generation module and the harmonic suppression module to mix output signals of the multi-phase generation module and the harmonic suppression module. The mixing circuit with high harmonic suppression ratio adds a harmonic suppression module on the basis of multi-phase mixing, thereby improving the harmonic suppression ratio of the output signal.