20. (Pathology) a break or fracture without complete separation of the two parts: a crack in the window. 21. a narrow opening or fissure 22. informal a resounding blow 23. (Medicine) a physical or mental defect; flaw 24. a moment or specific instant: the crack of day. 25. (Physi...
aWhat goes around the world but stays in a corner 什么在角落在世界,但逗留四处走动[translate] ainquisitions 侦查[translate] adiameter and 20 mm thick. The velocity of the projectile was measured using electrical contact-pins placed[translate] ...
In this work, a method focusing on elliptical rings was proposed for localization and imaging of micro-cracks in a three-dimensional structure using nonlinear Lamb waves with imperfect group-velocity matching. The width of the elliptical rings can be determined by the degree of the group-velocity...