First, the purpose of releasing one. No matter whether it is late in autumn or in winter or spring, the temperature drop can be as high as 40°C or more at noon. At this time, various synthetic enzymes and coenzymes in the plant lose activity, crop metabolism stops, photosynthesis stops, and no substance is produced. Plants that are too long can suffer heat damage. Longer times can cause the entire crop to die. At this point you need to vent the air to lower the temperature inside the shed. The optimum temperature for plant growth is between 20°C and 30°C. 2. The low temperature before dehumidification in the morning dehumidifies the air, which increases the humidity of the air. During the day, the temperature is high, and the transpiration of the soil and the crop is large, which increases the humidity in the greenhouse and causes condensation on the surface of the crop. The surface of the cover of the greenhouse covers the surface of the water droplets, which often condenses, and the interior of the greenhouse, such as smog, etc., often causes wetness on the crop surface, and is prone to various diseases. Therefore, the air should be promptly released and drained. For general crops, it is advisable to keep the indoor humidity at about 60%. 3. Adjusting the gas balance in the greenhouse The pesticide sprayed on the crop will decompose harmful gases. Manure will release ammonia gas. Poor quality plastic film and shed film will also release ethylene gas. These harmful gases will harm hazardous materials and should be discharged in time. Make fresh air into the shed. At the same time, the ventilation of greenhouses can balance carbon dioxide and photosynthesis of nail-spun crops. 4. The seedlings and hardened seedlings dwarf the seedlings and increase the disease resistance of the seedlings. Second, there are four ways to vent the air: bottom corner, rear window, chimney, and ridge quilting. The bottom corner and the rear window are not recommended for use in autumn, winter and early spring. Chimney-style and ridge quilting are two characteristics of the air release method is to suck the air inside the shed, instead of blowing cold air outside, its weakness is that the exhaust speed is slow, should open a large vent or in front of the curtain Exhale. In the morning, the temperature is low, the air saturation point is low, and the humidity is high. At this time, the moisture removal effect is the best. Third, the specific method of ventilation (take cucumber as an example) In the seedling stage, the small wind is used for the first time and the wind is amplified. During the day, the temperature is controlled at 20°C to 25°C and at night at about 15°C. Before the planting, the seedlings were cultivated at low temperature and played a dwarfing effect to prevent the flowers from being topping. 2. Fruiting period (1) Sunny: The main control temperature, the temperature at 16 °C, the humidity is 100%, 85% at 18 °C, with the increase of temperature, humidity decreased. During the day, when the temperature reached 30°C in the morning, the air was released. In the afternoon, the temperature dropped to 20°C. When the temperature was lowered to 13°C, the air vent was closed. The general rule is that when the sun is full, the temperature in the shed can increase by 7°C to 10°C per hour. The evening and the middle of the night are the main periods of nutrient conversion and transportation of cucumbers, and the temperature is most suitable at 20°C to 18°C. In the second half of the night, the respiration of plants is strengthened, nutrient consumption is more, and the temperature center is controlled at 15-13°C to reduce the respiration. (2) Cloudy days: It is mainly to control the humidity under the condition of keeping warm. In the morning, the air is released for half an hour. At noon, the air is released for 1-2 hours. In the evening, the air is released for about half an hour, and then the curtain is closed. At night, without closing the vents, some grass or direct curtain factory shall be paved at the vents, and a layer of plastic shall be laid on top to keep them warm. The rice straw will also absorb moisture. The thickness of the straw covered in the ditch is 10-20 cm, and the temperature is lower than 13°C.
Most products of Fluorine-Containing Benzaldehyde are a pale yellow liquid. They are playing an important role in fine chemical intermediates, is used as the main raw material for the synthesis of a variety of pesticides, pharmaceuticals, surfactants, polymer monomer mildew. As used in medicine synthesis antihypertensive drugs, antipyretic analgesic anti-inflammatory drugs, anti-cancer drugs, muscle relaxation drugs for synthesizing fluorine cypermethrin, fluorine chlorobenzene daisy cool in pesticides, fluoride and styrene, wherein the polymer of styrene monomer to fluorine can be widely used in the manufacture of the recording material, a thermoplastic resin coating, liquid crystal materials. Currently new miticide is effective pesticide products which is the main raw material of Fluorine-Containing Benzaldehyde.