Tungsten trioxide is used for many purposes in everyday life. It is frequently used in industry to manufacture tungstates for x-ray screen phosphors, for fireproofing fabrics and in gas sensors. Due to its rich yellow color, WO3 is also used as a pigment in ceramics and paints.In recent years, tungsten trioxide has been employed in the production of electrochromic windows, or smart windows. These windows are electrically switchable glass that change light transmission properties with an applied voltage.This allows the user to tint their windows, changing the amount of heat or light passing through.

The infrared emissivity modulation method by controlling the carriers in material. Based on the theory of electromagnetic wave, the relationship between emissivity and refractive index was discussed. The object with higher refractive index had lower emissivity. The refractive index of a material had relationship with the carrier concentration in it. The emissivity of material could be modulated by controlling the carrier concentration. Magnetron sputtering method was used to prepare WO3 thin film on ITO glass. The H+ ions and electrons were injected into or extracted out of the film by electrochemical method. The carrier concentration in the film was changed. It had a higher spectral reflectivity with the film of bleached, and a lower spectral reflectivity when the film is colored. The results show that the infrared emissivity can be modulated by controlling the carrier concentration.

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Hydrazinium oxalate tungstate complicated salts were prepared by using hydrazine , oxalic acid and tungstic acid as raw materials , and tungsten black oxides were prepared by using these complicated salts as precursors under the protection of purified nitrogen .The result from thermogravimetry points out that the thermal decomposition of the precursor completes at about 500 ℃.The ingredient of raw materials composing the precursor affects some properties of the product .The optimal ratio of hydrazine , oxalic acid and tungstic acid was determined to be 1 .0∶4 .0∶0 .5 .Temperature and time of thermal decomposition were experimentally found to affect the properties of the product too .When the precursor with the optimal ratio is thermally decomposed at 650 ℃ and for 30 min , the product is typically black and called model product .The O/W index and content of ammonium ion were determined . The O/W index is very close to that in W18O49 and the ammonium tungsten bronze is not enough to account under the selected condition .The powder XRD pattern of model product reveals that the main phase is a W18O49 one and the WO2 phase takes a little .Of the model product , the specific surface area (BET method)was measured to be12 m2·g-1and the agglomerate diameter (d50)3.68μm.

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Tungsten trioxide is used for many purposes in everyday life. It is frequently used in industry to manufacture tungstates for x-ray screen phosphors, for fireproofing fabrics and in gas sensors. Due to its rich yellow color, WO3 is also used as a pigment in ceramics and paints.In recent years, tungsten trioxide has been employed in the production of electrochromic windows, or smart windows. These windows are electrically switchable glass that change light transmission properties with an applied voltage.This allows the user to tint their windows, changing the amount of heat or light passing through.

Tungsten dioxide prepare process is ammonium paratungstate at about500℃ air calcined as tungsten trioxide, or a slight reduction to blue tungsten oxide at about 450℃ in hydrogen. Making tungsten filament  incandescent lamp is incorporated in a small amount of potassium hydroxide, silicon oxide and aluminum oxide in the tungsten trioxide or blue tungsten oxide, the amount does not exceed the sum of 1%, which is Baz invention in 1922 tungsten silk doping process. After doped  tungsten oxide reduction process of the metal tungsten powder with hydrogen. Reduction process is generally carried out in two steps: the first step to restore about 630℃ to tungsten oxide (brown tungsten oxide), the second step is reduced to tungsten metal powder at about 820 ℃. The purpose is to make the two-step reduction of potassium incorporated into full play the role and control of particle size. Such doped tungsten powder and then get in a special mold pressed into thin side bar. The side bar in hydrogen powered by self resistance heating (temperature of about 3000 ℃) method sintered tungsten sintered density can reach more than 85% of the theoretical value. This tungsten by swaging method can be processed into about 3mm in diameter tungsten rod, and then further processed by drawing mold into a variety of different ways thickness of the tungsten filament. For example 220V,15W incandescent tungsten filament with a diameter of about 15μm, and 10000W bromine tungsten lamp with a tungsten filament diameter of about 1.25mm. Finer tungsten as 220V, 10W incandescent tungsten filament diameter of about 12μm, will have to use the method to produce electrolytic corrosion.

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Tungsten carbide cutting tools are now in common use in industry. The differences in tool performance between cryogenically treated and untreated tungsten carbide tool inserts during the high-speed milling of medium carbon steel were analyzed. It has been found that cryogenically treated tools exhibit better tool wear resistance than untreated ones.It is also evident that the application of coolant during cutting helps to reduce tool wear experienced by the cryogenically treated tools even further very few papers have been published about the beneficial uses of a deep cryogenic treatment at 77 K on the properties of high speed steel.Thermal and cryogenic conditions were concurrently followed by down-thermal shock (pos- itive to negative temperature excursion) and up-thermal shock (negative to positive temperature excursion) treatments respectively on the composite laminates.
 

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