Abstract: Embodiments of the present disclosure provide a detection device for laser spot welding micro-weld spot quality based on laser ultrasound. The device includes: a nanosecond pulsed laser configured to emit a laser; the polarizing beam splitter configured to perform a laser beam splitting, wherein a laser beam after performing the laser beam splitting by the polarizing beam splitter enter an energy detector and a beam splitter mirror, respectively; the beam splitter mirror configured to perform the laser beam splitting on the laser entering the beam splitter mirror, wherein a laser beam after performing the laser beam splitting enter a photodetector and a light reflecting mirror, respectively; an aperture configured for the laser beam passing through the light reflecting mirror, the laser passing through a scanning galvanometer to reach a multi-axis displacement platform; the multi-axis displacement platform configured to place and/or move a sample.

Abstract: Provided is a method for regulating a thermal boundary conductance between a metal and an insulator, including: arranging a metal on a surface of an insulator, a contact surface between the metal and the insulator being a boundary between the metal and the insulator; and the insulator including a ferroelectric, a piezoelectric, or a pyroelectric; applying an external electric field or stress to the ferroelectric, and adjusting a magnitude of the external electric field or stress, or an included angle between a direction of the external electric field or stress with the boundary to regulate the thermal boundary conductance; or applying a stress to the piezoelectric, and adjusting a magnitude of the stress, or an included angle between a direction of the stress with the boundary to regulate the thermal boundary conductancer; or adjusting a temperature of the pyroelectric to regulate the thermal boundary conductance.