Keyphrases
Helium
100%
Porous Materials
100%
Sound Propagation
100%
Low-frequency Noise
100%
Noise Absorption
100%
Absorber
66%
Air-filled
22%
Acoustic Properties
22%
Sound Absorption
22%
Characteristic Impedance
11%
Wave Refraction
11%
Impedance Matching
11%
Finite Thickness
11%
Acoustic Impedance
11%
Absorption Material
11%
Effective Range
11%
Random Incidence
11%
Middle Range
11%
Low-density Gas
11%
Ductile Lining
11%
Sound Absorption Performance
11%
Oblique Incidence Angle
11%
Engineering
Frequency Noise
100%
Sound Absorption
100%
Sound Propagation
100%
Absorption Performance
33%
Test Rig
33%
Main Advantage
33%
Characteristic Impedance
33%
Absorption Material
33%
Oblique Incidence
33%
Duct
33%
Acoustic Impedance
33%
Incidence Angle
33%