Abstract: A method for determining a three-dimensional tortuosity of a loose and broken rock-soil mass, includes the following steps: a particle grading curve of the loose and broken rock-soil mass is obtained by utilizing a particle size analysis, and followed by calculating an equivalent particle size and an average particle size; a porosity of the loose and broken rock-soil mass is obtained by utilizing a moisture content test, a density test, and a specific gravity test; the three-dimensional tortuosity of the loose and broken rock-soil mass is obtained by utilizing the equivalent particle size, the average particle size and the porosity of the loose and broken rock-soil mass. The method has the advantages of simple logic, accuracy and reliability, simple and fast parameter determination, and has high practical value and promotion value in the field of environmental protection and ecological restoration technology.

Abstract: A shower head includes a case having a chamber with an opening, and a cover is slidably engaged with the opening and has multiple holes. The cover has an inner space defined therein, and a brush unit is rotatably located in the inner space and the chamber. The brush unit includes multiple blades, and each blade has brushes connected thereto. The brush unit rotates by the water flow so as to brush the inner surface of the chamber.