Abstract: The present disclosure relates to a method and a device for judging gas leakage, and an electronic device. The method includes: acquiring methane concentration data collected by monitoring devices, and generating a first function corresponding to the methane concentration data; acquiring a change rule of methane concentration in an inspection well during biogas accumulation, and generating a second function of the methane concentration changing with time; calculating a first correlation coefficient between the first function and the second function, and judging whether the first correlation coefficient is greater than a first preset threshold; acquiring a third function of gas consumption changing with time if no; and calculating a second correlation coefficient between the first function and the third function, judging whether the second correlation coefficient is less than a second preset threshold, and judging whether the gas leakage occurs based on the methane concentration data if no.

Abstract: The present disclosure relates to a method and a device for judging gas leakage, and an electronic device. The method includes: acquiring methane concentration data collected by monitoring devices, and generating a first function corresponding to the methane concentration data; acquiring a change rule of methane concentration in an inspection well during biogas accumulation, and generating a second function of the methane concentration changing with time; calculating a first correlation coefficient between the first function and the second function, and judging whether the first correlation coefficient is greater than a first preset threshold; acquiring a third function of gas consumption changing with time if no; and calculating a second correlation coefficient between the first function and the third function, judging whether the second correlation coefficient is less than a second preset threshold, and judging whether the gas leakage occurs based on the methane concentration data if no.

Abstract: A low copper-containing friction material composition used for brake pad is provided, which consists of 4-6 parts of aramid fiber, 2-2.5 parts of tire powder, 5-6 parts of magnesia, 5-6 parts of red vermiculite, 8-10 parts of ceramic fiber, 3.5-5 parts of magnetite, 7-8 parts of boron-containing phenolic resin, 15-17 parts of calcium sulfate crystal whisker, 16-18 parts of potassium titanate, 15-17 parts of barite, 5.5-7 parts of flake graphite, 6-8 parts of friction powder of cashew nut oil, 6-8 parts of calcined petroleum coke, 1.5-2 parts of boron nitride, 5-7 parts of flake aluminum powder, 0.4-0.5 parts of pure copper fiber, and 0.4-0.6 parts of black silicon carbide. The friction material composition has low content of heavy metal, wherein the content of copper is lower than 0.5%, has a satisfactory high temperature and thermal decay resistant performance, long service life, good abrasion resistance and stable friction coefficient.

Abstract: A copper-flee friction material composition for brake pads consists of: 0.43 parts of aramid fiber, 1.9 parts of tire powder, 6 parts of heavy magnesia, 2.55 parts of calcined petroleum coke, 8 parts of ceramic fiber, 6.5 parts of phenolic resin, 14 parts of aluminum silicate fiber, 22 parts of potassium hexatitanate crystal whisker, 25 parts of barite powder, 5 parts of granular graphite, 2 parts of antimony sulfide, 2.8 parts of friction powder of cashew nut oil, 0.9 part of boron nitride, 5 parts of flake aluminum powder, and 0.6 parts of tantalum carbide. Trials show that it has satisfactory high temperature and thermal decay resistant performance, long service life, good abrasion resistance and stable friction coefficient. With the friction material of the present invention used, the brake pad of vehicles is sensitive and stable during braking, produces no screech, is comfortable and has no damage on coupling plate.

Abstract: A low copper-containing friction material composition used for brake pad is provided, which consists of the following components by weight parts: 4˜6 parts of aramid fiber, 2˜2.5 parts of tyre powder, 5˜6 parts of heavy magnesia, 5˜6 parts of red vermiculite, 8˜10 parts of ceramic fiber, 3.5˜5 parts of magnetite, 7˜8 parts of boron-containing phenolic resin, 15˜17 parts of calcium sulfate crystal whisker, 16-18 parts of potassium titanate, 15˜17 parts of barite, 5.5˜7 parts of flake graphite, 6˜8 parts of friction powder of cashew nut oil, 6˜8 parts of calcined petroleum coke, 1.5˜2 parts of boron nitride, 5˜7 parts of flake aluminum powder, 0.4˜0.5 parts of pure copper fiber, 0.4˜0.6 parts of black silicon carbide. Said friction material composition is highly environmental friendly and has low content of heavy metal, wherein the content of copper is lower than 0.5%, and an excellent friction layer and transfer membrane can be formed when using said friction material composition.

Abstract: A copper-free friction material composition for brake pads consists of the following components by weight parts: 0.43 parts of aramid fiber, 1.9 parts of tyre powder, 6 parts of heavy magnesia, 2.55 parts of calcined petroleum coke, 8 parts of ceramic fiber, 6.5 parts of phenolic resin, 14 parts of aluminium silicate fiber, 22 parts of potassium hexatitanate crystal whisker, 25 parts of barite powder, 5 parts of granular graphite, 2 parts of antimony sulfide, 2.8 parts of friction powder of cashew nut oil, 0.9 part of boron nitride, 5 parts of flake aluminum powder, and 0.6 parts of tantalum carbide. The friction material of the present invention is environment-friendly material and contains little heavy metals; hence the friction material is highly environment friendly. And trials show that it has satisfactory high temperature and thermal decay resistant performance, long service life, good abrasion resistance and stable friction coefficient.

Abstract: A disc brake pad is composed of a backing plate and a friction material. The adhesion of the backing plate and the friction material is enhanced in the present invention by multiple recesses on the surface of the backing plate that is attached to the friction material. One of the advantages of the present invention is the ease of manufacturing. In one of the preferred methods of manufacturing, a matrix of recesses (2) is first impressed onto the steel sheet by a stamping press. The existing method of producing a traditional backing plate, i.e., stamping out the backing plate profile and the bores, may then be applied.