Abstract: The present application provides a loose tube and an optical cable having the same. The loose tube includes: a central portion including a first filler and a plurality of first optical units arranged within the first filler; an inner coating layer sleeved on the outer sidewall of the central portion; an intermediate layer sleeved on the outer sidewall of the inner coating layer, the intermediate layer including a second filler and a plurality of second optical units arranged within the second filler; an outer coating layer sleeved on the outer sidewall of the intermediate layer; and a separating portion arranged on the inner coating layer or within the intermediate layer and dividing the plurality of second optical units into a plurality of optical unit groups.

Abstract: An efficient blasting method for similar cutting in a rock tunnel is provided, which relates to the technical field of rock tunneling. The method includes the following steps: drilling: drilling central holes, lower cutting holes, upper cutting holes, auxiliary holes and peripheral holes in a cross section area for tunnel construction; filling explosives: filling explosives into the central holes, the lower cutting holes, the upper cutting holes, the auxiliary holes and the peripheral holes; and blasting: blasting following blast holes in turn to complete full-face one-time blasting in a millisecond delay blasting mode. The method is applicable for construction scenes of drilling and blasting methods.

Abstract: The present invention discloses an electrostatic air cleaner, comprising an upper filter screen, an electrode a, a tungsten wire, a spring, a main body, an ionization generator, a lower filter screen, an electrode b and an electrode c. The main body is a hollow structure, and the upper end of the main body is buckled with the upper filer screen and the lower end of the main body is buckled with a lower filter screen. A tungsten wire fixed at the upper end of the main body is provided at the inner side of the upper filter screen and the both ends of the tungsten wire are respectively connected with a spring, and the tungsten wire is tensioned by the spring to prevent sagging or deformation, wherein one spring is hitched on the electrode a, the electrode a is fixed on the upper end of the main body, and the main body is provided with an ionization generator.