Biological pesticides have the advantages of low toxicity, no residue, slow action and long duration. The ratio of concentration and dosage are lower than the exact bottom of the chemical. When the dosage is slightly larger, it will not cause phytotoxicity to plants, and it is safer for humans and animals, and does not pollute the environment. Therefore, people are concerned. Scientific use of biological pesticides to maximize the use of favorable factors and avoid adverse factors. The China Pesticide Network Xiaobian gives you a detailed introduction to the precautions during use:
Graphite is an elemental element of elemental carbon. Each carbon atom is surrounded by three other carbon atoms (arranged in a honeycomb-like hexagon) to covalently bond to form a covalent molecule.
Since each carbon atom emits an electron, the electrons are free to move, so the graphite belongs to the conductor. Graphite is one of the softest minerals, and its use includes the manufacture of pencils and lubricants. Carbon is a non-metallic element that is located in the second periodic IVA family of the periodic table.
The specific use of graphite
1, for refractory materials, including refractory bricks, crucible, continuous casting powder, casting core, mold detergent and high temperature materials.
Magnesium carbon brick refractory material is the mid-60s, developed by the United States; in the world of magnesium carbon brick has been widely used in steel, and has become a traditional use of graphite. Aluminum carbon brick aluminum carbon refractories are mainly used for continuous casting, flat billet from the pipeline of the protective cover, underwater nozzle and oil well blasting tube.
Made of graphite and refractory crucible and its related products, such as crucible, curved neck bottles, plugs and nozzles, etc., with high fire resistance, low thermal expansion, melting metal process, by metal infiltration and erosion But also stable, good thermal shock stability at high temperatures and excellent thermal conductivity, so the artifacts and its related products are widely used in direct melting metal process.
2, steelmaking
Graphite and other impurity materials can be used as carbonizers in the steelmaking industry. Carburizing uses a wide range of carbonaceous materials, including artificial graphite, petroleum coke, metallurgical coke and Natural Graphite. In the world of steel-making carbon-based graphite is still one of the main uses of earth-like graphite.
3, for the conductive material
Graphite in the electrical industry is widely used as electrodes, brushes, carbon rods, carbon tubes, mercury rectifier cathode, graphite gaskets, telephone parts, TV picture tube coating and so on. Among them, Graphite Electrode is the most widely used, in the smelting of various alloy steel, ferroalloy, the extensive use of graphite electrodes. The graphite used in the electrical industry is very demanding on grain size and grade.
4, for wear and lubrication materials
Graphite is often used as a lubricant in the machinery industry. Lubricants are often not used in high-speed, high-temperature, high-pressure conditions, and graphite wear-resistant materials can be 200 ℃ a 2000 ℃ temperature and at a high sliding speed (loom / s) without lubricating oil work. Many of the equipment that transport corrosive media, widely used graphite materials made of piston rings, seals and bearings, they run, do not need to add lubricants, graphite milk is also a lot of metal processing (wire drawing, pull tube) when the good lubricant.
5, for corrosion-resistant materials
Graphite has good chemical stability. After special processing of graphite, with corrosion resistance, good thermal conductivity, low permeability and other characteristics, and widely used in the production of heat exchangers, reaction tank, condensate, combustion tower, absorption tower, cooler, heater, filter Pumps and other equipment. These equipment for the petrochemical, hydrometallurgical, acid and alkali production, synthetic fiber, paper and other industrial sectors, can save a lot of metal materials.
6, for the atomic energy industry and the defense industry
Graphite has a good neutron deceleration performance, the earliest as a slowdown agent for atomic reactors, "uranium-graphite" reactor is currently used more of an atomic reactor. As the power of the atomic energy reactor in the slowdown material should have a high melting point, stable, corrosion-resistant properties, graphite can meet the above requirements.
7, for anti-scaling anti-rust materials.
Graphite can prevent boiler fouling. Tests have shown that adding a certain amount of Graphite Powder to the water prevents the surface of the boiler from scaling. In addition, graphite coated with metal chimneys, roofs, bridges, pipes can be anti-corrosion and rust.
8, graphite new use
1) Flexible graphite products. Flexible graphite, also known as Expanded Graphite, is the 1970s developed a new graphite products. 1971 US research success of flexible graphite sealing material, to solve the problem of atomic valve leakage, followed by Germany, Japan, France also began to develop production. In addition to this product has the characteristics of natural graphite, but also has a special flexibility and flexibility. Therefore, it is an ideal sealing material, widely used in petrochemical, atomic and other industrial fields, the international market demand growth year after year.
2) the production of semi-metallic friction materials. Since the 1970s, clutches and automatic liners have been widely used semi-metallic friction materials. Semi-metallic friction material is the graphite and metal powder, steel fiber, clay powder made of synthetic resin. These automatic lining can be used for high-speed equipment such as aircraft, trucks and off-road vehicles, and clutch pads.
Graphite Carbon Graphite,Graphite Mineral,Monolithic Graphene,Graphite Crystal Fengcheng Ruixing Carbon Products Co., Ltd , http://www.lnfcrxts.com
1. Different biological pesticides have different control objects in the practical application of biological pesticides. Many people still don't fully understand the nature of biological pesticides. They mistakenly believe that biological insecticides and fungicides can prevent and cure all diseases and insect pests, and they are not widely used. This will not only prevent the effects, but also delay the prevention and treatment. period. Biopharmaceutical selectivity is very strong. For example, Bacillus thuringiensis (Bt) is effective for controlling lepidopteran larvae, but it is not pathogenic to the leafhopper of the same wing, and the control effects of different strains of Bacillus thuringiensis on several important pests are also There are differences. In addition, different types of biological pesticides should be used according to the feeding characteristics of pests. For example, Bt has a good effect on lepidopteran pests. After spraying, it will be distributed on the surface of plants, causing pests to feed or bacteria to die, but pests that suck the juice. (such as mites, mites) is not effective, and avermectin has a very good effect on mites. Therefore, suitable biopesticide varieties should be selected in a targeted manner for different types of pests. The use of bio-pesticides advocates the use of two or more drugs. In the case of prophylaxis and continuous use, one drug can be used alone, but it should not be used alone during the high incidence of pests and diseases.
2, the selection of suitable biological pesticide formulations Biological pesticides are often closely related to the dosage form and use technology. When using, according to the control object, meteorological conditions and use time, the correct dosage form should be selected correctly to achieve the best control effect. For example, the powder can be dispersed in a large range by means of air buoyancy and wind, so that it has greater contact with pests; for pests with a large amount of edible leaves, the method of adding wettable powder to water to form a suspension can be sprayed better. The effect of using the dusting method is poor. Capsules not only have a long release effect. And it can protect the pathogens from environmental factors. Can be used in greenhouses.
3, to determine the appropriate slow <br> prevention and treatment of biological pesticides period, should be used in young larvae of pests. Many biological pesticides have a slow insecticidal effect, which is inferior to chemical pesticides. Therefore, the medication should be 2-5 days earlier than the chemical pesticide. Such as BT emulsion, Beauveria bassiana, etc., after spraying, the pests gradually die after 3-5 days.
4. Pay attention to the climatic conditions of spraying. The use effect of biological pesticides is greatly affected by environmental factors:
4.1 Temperature. When spraying bio-pesticide, it must be controlled at an ideal temperature above 20 °C. The secret is that the active ingredient of this kind of pesticide is composed of protein crystals and living spores. Once sprayed below the above temperature, then The rate of propagation of spores in the body of the pest is very slow and the protein crystals are difficult to exert their effects, often showing no control effect after application. According to the experimental data, the bio-pesticidal effect after spraying is 1-2 times higher than the insecticidal efficiency between 10-15 °C between temperatures of 25-30 °C.
4.2 Humidity Biological pesticides are also extremely sensitive to humidity requirements. The greater the environmental humidity, the more significant the efficacy of spraying biological pesticides, especially for powdered biological pesticides.
4.3 The ultraviolet rays in the sunlight have a lethal killing effect on spores. Scientific experiments show that direct sunlight for 30 minutes will kill the spores by 50% in one fell swoop. After one hour of irradiation, the spore mortality rate is as high as 80%, and ultraviolet rays. The radiation can also produce deformation and effect on the parasporal crystals, so the effect of using it after 4 o'clock in the afternoon or on a cloudy day will be greatly exerted.
4.4 Rainwater spores are most afraid of heavy rain, so it should be carried out according to the weather forecast, because the rain will wash away the sprayed bacteria and lose the lethality. If it is rained (light rain) after spraying (5-6 hours later), it will not reduce the efficacy, but it will improve the control effect. The original rain is very beneficial to spore germination, and the pest accelerates its death once it is eaten. .
5, suitable spray equipment Most biological pesticides are not systemic, spray should pay attention to spray evenly to achieve good results, in practical applications, most plant protection equipment is currently using less efficient, usually from top to bottom Directly spray on the crop, so that a large number of pesticides are concentrated on the leaves above the crop. The pesticides attached to the lower and middle leaves of the crop are less, and the loss of falling on the soil surface is more. If the fog is large, the loss is even greater. Due to the high production cost of biological pesticides, it is necessary to select plant protection equipment with high spraying efficiency, good atomization degree and pesticide saving. Such as mist sprayer, mist sprayer, etc.
6. Mixing of biological pesticides 1 Mixing of biological insecticides: Bio-insecticides are turbid and mixed with most chemical pesticides, because most chemical pesticides are chemically acidic and physiologically neutral, and there are no bacteria or fungi. The inhibitory effect and the neutralization reaction can be sufficiently mixed. It can be seen that the biological insecticide can not be mixed with the chemical fungicide. Once compounded, the active bacterial spore of the biological agent will be killed and lose its proper effect. 2 Mixing of biological fungicides: Biological fungicides can be mixed with most chemical agents and biological agents, but they cannot be mixed with alkaline drugs. Only a few kinds of drugs cannot be mixed with acidic agents. For example, Trichoderma can be used with most Biocides and chemical pesticides are mixed at the same time.
7, with the use with the use of the accompanying with the use of a good pesticide once used, such as Beauveria bassiana, with good pesticides sprayed within 2 hours. In order to prevent premature germination of spores, loss of effectiveness.
8, pay attention to the storage of pesticides <br> Network Tips: biological pesticide storage location requires a cool, dry, damp to avoid failure. For example, Suyun gold stalk, Jinggangmycin, etc., are characterized by high temperature resistance, storage resistance, easy moisture absorption and mildew, inactivation failure, and the shelf life cannot exceed 2 years. 