Rail is produced by the killed steel of Open hearth furnace smelting,rail production should use the production technology which is not producing white dot. The tensile strength of for rail is not less than 90 kg/mm. Rail surface can not have crack, folding, scarring, bubbles and inclusions. Allow a depth not bigger than the rail size allowing negative deviation value of indentation, pitting and scratches and depth is not greater than 1 mm of hair lines.The surface of rail end can not have crack, delamination and shrinkage cavity residual. Rail end should be upright, a cut to face askew in any direction shall not be bigger than 5 mm. Length of not less than 4 mm burrs should be removed. Longitudinal clean-up rail surface defects allowed to use pneumatic shovel, clean up the depth (single) allow negative deviation shall not be greater than the size. The rail surface defects are not allowed to weld or fill.
Train Rail,Train Steel Rail,Crane Steel Train Rails,High Speed Train Rail CANGZHOU HAOYUAN PIPE FITTINGS MFG CO.,LTD , http://www.pipefitting-china.com
Second, symptomatic medication. There are various types of pesticides, such as fungicides, insecticides, herbicides, and plant growth regulators. In the period of purchasing pesticides, we must pay attention to "the right medicine." Nowadays, farmers tend to buy medicines, which tend to be fashionable and expensive. That is, what other people use what I use, what is the price and what effect is good, but forget that the crops are also the same as people, the medicines should be used for the disease, and the insecticides cannot be used for sterilization. Also. In addition, there are many varieties of insecticides and fungicides, and it is necessary to select the specific drugs for pests and diseases as much as possible. For example, the use of dimethoate in the control of wheat bran is very cost-effective.
Third, timely medication. People often hear complaints about fake drugs and low efficacy. In fact, many pesticides are not fake or bad. It’s just that the time used is not right, and it has not achieved the expected results. Each pest has a critical period of prevention and control, and timely medication can do more with less, and once it is missed, it is difficult to achieve the desired results. For example, the key period of prevention and control of wheat powdery mildew is in the incidence center and the disease leaf rate is more than 15% before the pandemic; the key to control cotton bollworm is the egg hatching period and the second instar larval stage. In addition, it is best to spray in sunny and windless weather, morning and evening (before 9 am, after 4 pm). Many farmers' friends mistakenly believe that the higher the temperature, the better the drug effect, and often choose to take the drug at noon. I don't know if many of the pests are afraid of heat at this time, and the medicine is not as good as the insects. Moreover, most pesticides are easily decomposed under high temperature, and high temperature operations are also likely to cause poisoning accidents among employees.
Fourth, the right amount of medication. People often treat worms and think that the bigger the dose, the better. Although the amount of medicine is small, it is not effective, but the amount of medicine is large. In addition to causing waste, it is also prone to phytotoxicity and human and animal poisoning accidents. If the concentration of the drug solution is too large when using the dichlorvos to control the cotton aphid, the cotton leaves will dry up and even the cotton plant will die. The herbicide is used, and the concentration requirements are more strict. It must be properly proportioned according to the prescribed dosage, slightly inadvertent. The grass will die. Therefore, it must be based on the growth of crops and the extent of pests and diseases, the right ratio, reasonable use. Under normal circumstances, crops grow vigorously, when the pests and diseases occur seriously, the amount of medicine is small; when the seedlings and pests occur less lightly, the dosage is small.
Fifth, the method should be appropriate. According to different pests and diseases, choose different prevention methods, such as seed dressing, bait bait, stalking, dusting, spray, etc. For the seed-borne diseases, the method of seed dressing is generally adopted, such as the use of seed dressing such as pentachloronitrobenzene to control wheat smut. For the prevention and control of underground pests, the method of scatter bait is generally adopted. But no matter which method you choose, you should use it evenly and thoughtfully.
6. Alternate or mixed medication. Long-term use of a single pesticide, pests are highly susceptible to drug resistance, such as the long-term single use of pyrethroid pesticides to control cotton bollworm, resulting in enhanced resistance of cotton bollworm. According to different pests, multiple pesticides can be used at the same time or two or more kinds can be selected according to the characteristics of the pesticide, which can effectively delay the generation of drug resistance.
Seven, pay attention to the protection of natural enemies. Each pest has its natural enemies. For example, the seven-star ladybug has the name of “蚜 â€â€. When the ratio of the wheat field to the ladle is not less than 1:150, it is not necessary to use drugs. In addition, when controlling pests, it is necessary to use selective pesticides as much as possible, and strive to select pesticides that are only effective against pests, so that natural enemies can be well protected and insect pest control effects can be achieved. Biological control not only reduces costs, is safe and effective, but also improves the quality of agricultural products.
Agriculture and Animal Husbandry Bureau of Zanhuang County, Shijiazhuang City, Hebei Province
Product:Train Rail
Size:9KG/M-QU120
Materials: Q235,55Q,U71Mn,50Mn,45Mn
Thickness:/
Standard: GB 2585-2007,
Crafts: Hot rolling
Connection: Welding.Fish Plate.
Package: According to customer requirements.
Brand Name: HY
Place of Origin: China (Mainland)
Certification: API 5L.ISO.UKS.SGS.BV
Application: Chemical, Water, Oil and gas, Electricity
First, the base must be clear. Be sure to grasp the physical and chemical properties, control objects and precautions of the pesticides used. Each pesticide has its own chemical characteristics, applicable conditions and scope of prevention and control, and each type of control object (paths and pests) has its own development law. Its weak link is the best time for our medication. That is, the prevention and control period. In this way, we can do our best in mind.
ã€Comment】 ã€Print this article】 ã€Close this page】 ã€Large, medium and small】