Abstract: A riding mowing device includes a seat used for a user to sit on and including a seat cushion and a backrest; a frame for supporting the seat; a cutting assembly including a cutting deck and a mowing element for mowing grass, where the mowing element is at least partially accommodated in the cutting deck, and the cutting assembly is mounted to the frame; a traveling assembly for driving the riding mowing device to travel; a control circuit board for controlling at least the cutting assembly and the traveling assembly; and a power supply assembly for supplying power to at least the cutting assembly and the traveling assembly. At least part of the control circuit board is disposed between the seat and the power supply assembly.

Abstract: The present invention provides a trabecular porous tantalum dental implant and a preparation method thereof. The trabecular porous tantalum dental implant provided by the present invention has a cylindrical structure, and sequentially includes a top functional area, a middle functional area and a bottom functional area from top to bottom. The top functional area has a compact structure. The middle functional area has a porous bionic trabecular structure. The bottom functional area has a compact structure. The trabecular porous tantalum dental implant is integrally prepared through an additive manufacturing technology by using pure tantalum or medical tantalum alloy powder as a raw material. The trabecular porous tantalum dental implant provided by the present invention has a high friction force, strength and modulus close to those of human bones, an excellent bone ingrowth effect, high implantation stability and long service life.