Comparing Figure 4 (b) and Figure 6, can be seen on the same resonant frequency (for 36.5kHz), a different ladder material (a person of aluminum, steel materials to another person), seems to point to no significant change of . This shows that the point of the disc material has little to do with the

Figure 4 (b) compared with Figure 6, as can be seen, the same resonant frequency (36.5 ), kHz materials (A different ladder for aluminum alloy steel material, and the other one is), point to appear to be no noticeable change. This illustrates that point to sexual and ladder up little relationship ma

Compared with Figure 4(b) with Figure 6, may see, to the identical kind of resonance frequency (is 36.5kHz), the different steps and ladders material (one is aluminum alloy, another one for steel material), the directive property as if changes not obviously.This indicated the directive property and

Figure 4 (b) and Figure 6, you can see that, on the same resonant frequency (36.5kHz), the ladder of different materials (yizhe for aluminum alloy, another yizhe steel materials), nature seems to be no obvious change. This shows links to material is not so much as the ladder disk.

Compare Figure 4 (b) fig 6, can see on resonant frequency (36.5kHz) ladder, different materials (yizhe for aluminum alloy, other steel materials), nature seems no obvious changes. This shows links to material is not so much as the ladder disk.