Abstract: A combustion method for controlling and monitoring exhaust gas emissions in boilers is provided. The combustion method comprises the following steps: providing a liquid fuel in a boiler, burning the liquid fuel under atmospheric pressure; measuring a first combustion temperature in the boiler, and monitoring an initial concentration of a first exhaust gas in the boiler; adding a combustion improver to the boiler in batches and monitoring an emission concentration of the first exhaust gas in the boiler, wherein the emission concentration is less than the initial concentration; and repeating the above steps, and monitoring the boiler until a second combustion gas is generated, stop adding the combustion improver, and measuring the temperature in the boiler as a second combustion temperature, and reducing the amount of the combustion improver to avoid the generation of the second exhaust gas.

Abstract: A diffraction-type 3D display element is arranged on an image output face of a 3D display device and comprises a first diffraction area and a second diffraction area. The first diffraction area has a plurality of first stepped gratings spaced apart from each other. The second diffraction area has a plurality of second stepped gratings spaced apart from each other. The second diffraction area is adjacent to the first diffraction area and is arranged symmetrically to the first diffraction area with a central line being the symmetric axis. The diffraction-type 3D display element of the invention diffracts the images output by the 3D display device and projects the diffracted images to two different viewing areas to provide 3D images for users.

Abstract: An LED package includes an LED die and a lens module. The lens module covers the LED die. Light emitted from the LED die travels through the lens module. The lens module includes a concave lens and a convex lens with a smaller radial dimension than that of the concave lens. The concave lens covers the LED die. The convex lens is attached on a center of a surface of the concave lens away from the LED die. Optical axes of the concave lens and the convex lens are both collinear with a central axis of the LED die. Light from the LED die is diverged by the lens module to a peripheral side of the LED package.

Abstract: An LED package includes an LED die and a lens module. The lens module covers the LED die. Light emitted from the LED die travels through the lens module. The lens module includes a concave lens and a convex lens with a smaller radial dimension than that of the concave lens. The concave lens covers the LED die. The convex lens is attached on a center of a surface of the concave lens away from the LED die. Optical axes of the concave lens and the convex lens are both collinear with a central axis of the LED die. Light from the LED die is diverged by the lens module to a peripheral side of the LED package.

Abstract: A diffraction-type 3D display element is arranged on an image output face of a 3D display device and comprises a first diffraction area and a second diffraction area. The first diffraction area has a plurality of first stepped gratings spaced apart from each other. The second diffraction area has a plurality of second stepped gratings spaced apart from each other. The second diffraction area is adjacent to the first diffraction area and is arranged symmetrically to the first diffraction area with a central line being the symmetric axis. The diffraction-type 3D display element of the invention diffracts the images output by the 3D display device and projects the diffracted images to two different viewing areas to provide 3D images for users.