摘要:
A hearing protection process comprises (a) providing at least one hearing protection device comprising at least one sound barrier comprising at least one substantially periodic array of structures disposed in a first medium having a first density, the structures being made of a second medium having a second density different from the first density, wherein one of the first and second media is a viscoelastic medium having a speed of propagation of longitudinal sound wave and a speed of propagation of transverse sound wave, the speed of propagation of longitudinal sound wave being at least about 30 times the speed of propagation of transverse sound wave, and wherein the other of the first and second media is a viscoelastic or elastic medium; and (b) interposing the hearing protection device between an acoustic source and an acoustic receiver in the form of a human ear.
摘要:
A hearing protection process comprises (a) providing at least one hearing protection device comprising at least one sound barrier comprising at least one substantially periodic array of structures disposed in a first medium having a first density, the structures being made of a second medium having a second density different from the first density, wherein one of the first and second media is a viscoelastic medium having a speed of propagation of longitudinal sound wave and a speed of propagation of transverse sound wave, the speed of propagation of longitudinal sound wave being at least about 30 times the speed of propagation of transverse sound wave, and wherein the other of the first and second media is a viscoelastic or elastic medium; and (b) interposing the hearing protection device between an acoustic source and an acoustic receiver in the form of a human ear.
摘要:
A sound insulation process comprises (a) providing at least one sound barrier comprising at least one composite resonator element; and (b) placing the at least one sound barrier in at least one gas stream that is at least partially enclosed.
摘要:
A sound barrier comprises a substantially periodic array of structures disposed in a first medium having a first density, the structures being made of a second medium having a second density different from the first density, wherein one of the first and second media is a porous medium other than a porous metal, the porous medium having a porosity of at least about 0.02, and wherein the other of the first and second media is a viscoelastic or elastic medium.
摘要:
A sound barrier comprises a substantially periodic array of structures disposed in a first medium having a first density, the structures being made of a second medium having a second density different from the first density, wherein one of the first and second media is a porous medium other than a porous metal, the porous medium having a porosity of at least about 0.02, and wherein the other of the first and second media is a viscoelastic or elastic medium.
摘要:
A sound barrier comprises a substantially periodic array of structures disposed in a first medium having a first density, the structures being made of a second medium having a second density different from the first density, wherein one of the first and second media is a viscoelastic medium having a speed of propagation of longitudinal sound wave and a speed of propagation of transverse sound wave, the speed of propagation of longitudinal sound wave being at least about 30 times the speed of propagation of transverse sound wave, and wherein the other of the first and second media is a viscoelastic or elastic medium.
摘要:
A sound barrier comprises a substantially periodic array of structures disposed in a first medium having a first density, the structures being made of a second medium having a second density different from the first density, wherein one of the first and second media is a viscoelastic medium having a speed of propagation of longitudinal sound wave and a speed of propagation of transverse sound wave, the speed of propagation of longitudinal sound wave being at least about 30 times the speed of propagation of transverse sound wave, and wherein the other of the first and second media is a viscoelastic or elastic medium.
摘要:
A sound insulation process comprises (a) providing at least one sound insulation device comprising at least one sound barrier comprising at least one substantially periodic array of structures disposed in a first medium having a first density, the structures being made of a second medium having a second density different from the first density, wherein one of the first and second media is a viscoelastic medium having a speed of propagation of longitudinal sound wave and a speed of propagation of transverse sound wave, the speed of propagation of longitudinal sound wave being at least about 30 times the speed of propagation of transverse sound wave, and wherein the other of the first and second media is a viscoelastic or elastic medium; and (b) interposing the sound insulation device between an acoustic source area and an acoustic receiving area of a transportation vehicle.
摘要:
A sound insulation process comprises (a) providing at least one sound insulation device comprising at least one sound barrier comprising at least one substantially periodic array of structures disposed in a first medium having a first density, the structures being made of a second medium having a second density different from the first density, wherein one of the first and second media is a viscoelastic medium having a speed of propagation of longitudinal sound wave and a speed of propagation of transverse sound wave, the speed of propagation of longitudinal sound wave being at least about 30 times the speed of propagation of transverse sound wave, and wherein the other of the first and second media is a viscoelastic or elastic medium; and (b) interposing the sound insulation device between an acoustic source area and an acoustic receiving area of a transportation vehicle.
摘要:
An apparatus and method for microcontact printing are described. The microcontact printing apparatus includes a planar stamp and a pressurized roller. The pressurized roller includes an inflatable bladder that can be inflated by a fluid to a pressure that reduces printing defects such as voids and stamp collapse. A substrate is disposed between the pressurized roller and a stamp coated with an ink of functionalizing molecules. As the pressurized roller moves over the substrate, at least a portion of the functionalizing molecules are transferred from the stamp to the substrate in the desired pattern.