In fact, excessive application of nitrogen fertilizer in vegetables poses a serious threat to people's health. The nitrate content of vegetables with excessive nitrogen application is 20-40 times that of normal conditions. Nitrate is converted into nitrite during transport or storage in the human body or in vegetables. Nitrite combines with various amines in the human body to form a strong carcinogen, nitrite.
Excessive application of nitrogen fertilizer also causes serious pollution to soil and water. Long-term application of large amounts of nitrogen fertilizer, especially ammonium sulfate, chlorination, etc., will gradually acidify the soil. The toxic substances such as sulfate, chloride and biuret remaining in the soil gradually reduce the microorganisms and cockroaches in the soil. The acidification of the soil also accelerates the leaching of nutrients in the soil, eventually causing the soil to be compacted and losing the value of cultivation.
Vegetables should pay attention to the application of nitrogen fertilizer. When applying nitrogen fertilizer, it is necessary to measure the amount to prevent excessive. Non-polluted cultivated vegetables should be banned from nitrate-nitrogen fertilizer and compound fertilizer produced from nitrate-nitrogen fertilizer. Adopt scientific fertilization method: the base fertilizer is mainly composed of decomposed organic fertilizer, and combined with phosphorus and potassium fertilizer. Topdressing should be based on the amount of fertilizer needed in different growth stages of vegetables. Note that the base fertilizer should be applied layer by layer, deep application or ditch application. Foliar spray or combination with watering and top dressing. Vigorously promote organic fertilizer and reduce the amount of nitrogen fertilizer. It is necessary to use more fully-fertilized high-quality livestock and poultry manure and other manure, and rational use of human excrement. Manure must be treated by accumulation, full fermentation, etc., and can be fermented by biogas at high temperature. Human excrement should be stored in a septic tank for fermentation, and add 3-5% superphosphate and gypsum powder to reduce the volatilization and loss of ammonia.
Thin wall ball bearings are simple in structure and easy to use. Mainly used to bear radial load, but when the radial clearance of the bearing is increased, it has a certain performance of Angular Contact Ball Bearing and can bear combined radial and axial load.
When the speed is high and thrust ball bearings are not suitable, thin wall ball bearings can also be used to bear pure axial loads. Compared with other types of bearings of the same size, this type of bearing has a small friction coefficient and a high limit speed. But it is not impact resistant and not suitable for heavy loads.
Thin wall ball bearings have a bearing inner diameter and outer diameter ratio less than a specified value. The ratio of bearing outer diameter to bearing inner diameter is 1.25 or less. It is called thin wall ball bearings, which means that the outer diameter-inner diameter value of the bearing is very small and the bearing wall is very thin.
The precision required by thin wall ball bearings is very high, because the wall is very thin, so the weight it can carry is also very low, and the impact resistance is very poor, so this must be selected according to the use environment!
Characteristics
The specific use of thin wall ball bearings:
Model airplanes, remote control cars, machine tools, motors, water pumps, agricultural machinery, textile machinery, laser printers, instruments, measuring instruments, electronic accessories, motors, motors, etc.
Welcome to contact me to get the price of thin wall ball bearings!
Thin Wall Ball Bearing,Thin Section Bearings,Thin Ball Bearing,Thin Wall Bearing
Shijiazhuang Longshu Mechanical & Electrical Equipment Trading Co., Ltd. , https://www.longsbearings.com