From the luminescence mechanism of fluorescent lamps, phosphors play a key role in the quality of fluorescent lamps. Fluorescent lamps after the 1950s mostly use calcium halophosphate, commonly known as halogen powder. The halogen powder is cheap, but the luminous efficiency is not high enough, the thermal stability is poor, the light decay is large, and the lumen maintenance rate is low. Therefore, it is not suitable for use in a thin tube diameter compact fluorescent lamp. In 1974, Philips in the Netherlands first developed a phosphor cerium oxide (red light, peak wavelength 611 nm) and magnesium polyaluminate (green light) that will emit red, green and blue light that is sensitive to the human eye. The peak wavelength is 541 nm) and the magnesium polyaluminate bismuth (blue light, peak wavelength is 450 nm) is mixed into a three-primary phosphor (completely named rare earth element trichromatic phosphor) in a certain ratio, and its luminous efficiency is high (average luminous efficiency) Above 80lm/W, about 5 times that of incandescent lamps), the color temperature is 2500K-6500K, and the color rendering index is about 85. Using it as a raw material for fluorescent lamps can greatly save energy, which is the reason for high-efficiency energy-saving fluorescent lamps. It can be said that the development and application of rare earth element trichromatic phosphors is an important milestone in the history of fluorescent lamps. Without a three-primary phosphor, it is impossible to have a new generation of thin-tube compact high-efficiency fluorescent lamps today. However, the rare earth element trichromatic phosphor also has its disadvantages, and its biggest disadvantage is that it is expensive.
Galvanized Roller Shutter Door
Using advanced hot-dip galvanized material , precision roll forming production process, polyurethane foam that free of hydrofluorocarbon inside door, light weight, high strength, appearance nice. The doors have advantages of tamper anti-theft , noise isolation thermal insulation and corrosion resistance;the doors are widely used in shops, garages, houses, supermarkets, warehouses and industrial plants,etc.
Depending on the characteristics of the buildings,we can choose interior, exterior and intermediate three different installation ways, doors stay in the upper part of door after rolling up , this could save garage space, and also could keep the garage clean and beautiful by prevent the mud, rain and snow ,etc going into the garage.
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