This year, the tomato planting area in summer greenhouses in our province is larger. According to last year's tomato disease incidence and prevention and treatment experience, prevention and treatment of tomato leaf curl virus disease are summarized and summarized for the reference of farmers.

After the infected plants became infected, the yellowing of the upper leaves became smaller and the leaf margins curled up. The leaves shrank and curled, the internodes became shorter, the flowering results were difficult, the fruit type was small, and the ripening was slow. The diseased plants grew slowly and became dwarfed.

Harmful Tomato Leaf Curl Virus Disease is a devastating disease that can develop from seedling to harvest. Tomato leaf curl virus disease began to spread between individuals affected by B. tabaci, and then gradually expanded the scope of the disease, and can be spread through agricultural operations such as pests and farmers in the management of snoring. In summer and autumn of 2006, the disease occurred in a large area in Zhejiang and other provinces. From August to October 2007, the disease occurred in Fugou County of our province. The commonly occurring plots of tomato leaf curl virus disease can reduce production by 50% to 80%. In severe cases, there is no fruit in the whole shed. There is currently a tendency to spread from south to north.

The key to prevent and cure tomato leaf curl virus is to prevent the occurrence and harm of Bemisia tabaci in the early stage of tomato. About one month after seedling and transplanting is the most critical period for the control of Bemisia tabaci. Use 40 to 60 mesh insect-repellent nets when raising seedlings to prevent the entry of whiteflies. At the same time, spray the systemic drug Aketai 2500 times. Before transplanting, use Aketai 2500 times to irrigate the roots. The validity period is 20 months. ~30 days, not only can prevent the occurrence of pre-blight fly whitefly, but also can play the role of strong seedlings; after transplanting, the greenhouse vents should be closed with more than 40 mesh pest control nets, the best hanging pest control board, found In the case of tobacco whitefly, it is necessary to carry out drug control. A better control method is to tightly vent the shed, use fumigant to fumigate it once in the evening, and use Aktai 2500 times for spraying prevention the next day. Once onset, in addition to spraying insecticides to control Bemisia tabaci, it is also necessary to spray the agents that prevent and treat the disease, such as virus A, triazophosazole, phytopathogenic spirit, and Ningnanmycin. High temperature and drought are also the conditions for the occurrence of Tomato Leaf Curl Virus disease. It is well ventilated, hard to pour, and reduces the temperature inside the shed. It can also effectively prevent the occurrence of the disease.

Sheet Metal Fabrication

Sheet Metal Fabrication

Definition of sheet metal fabrication

Sheet Metal fabrication is the creation of useful metallic parts and structures by the application of multiple fabrication processes. Sheet metal fabrication is basically a broad term that involves various complex processes like cutting, forming, bending, welding, machining, and assembling. The instructions include below: materials, processes, and tools required for sheet metal fabrication.

Types of Sheet Metal Fabrication Materials

The choice of metal depends on the final use of the fabricated parts.

Common fabrication processes:

· Carbon Steel

· Stainless Steel

· Aluminum

· Bronze

· Copper

· Brass

· Aluminized steel

· Galvanized steel

Types of Metal Fabrication Processes

The journey to the final product from raw sheet metals proceeds through various sheet metal fabrication processes. All the sheet metal fabrication processes can be grouped into the following three categories:

· Cutting

· Deformation

· Assembly

Sheet metal fabrication: Cutting

i. Laser Cutting

ii. Water jet cutting

iii. Plasma cutting

Sheet metal fabrication: Forming or Deformation

Bending: Sheet metal bending is one of the most popular deformation processes. A machine known as a Press brake is used to bend sheet metals into V, U, or other complex shapes. With an increase in gauge thicknesses of sheet metals the force required to bend increases.

Stamping: In the stamping process, a hydraulic or mechanical stamping press equipped with a tool and die is used to perform specific tasks like curling, drawing, embossing, flanging, etc

Hemming: Hemming is a process by which the edges of sheet metal are folded over itself or another piece of sheet metal to create a rounded edge. In the sheet metal fabrication process, two types of hemming processes are widely involved. They are roll hemming and conventional die hemming. Conventional hemming is used for mass production. A hemming roller is used for roll hemming.

Spinning: Spinning is a metal fabrication process where a lathe machine is used to rotate the sheet metal against a tool to produce conical or cylindrical shapes.

Sheet metal fabrication: Assembly

Assembly is basically joining sheet metal components produced using above mentioned cutting or bending processes. The common sheet metal assembly process consists of joining by Welding and joining using fasteners.

Welding: In the welding process, sheet metal components are joined together by melting sections with the application of heat to form a solid connection. There are various processes available that are used to weld sheet metals.

Joining using Fasteners: Similar or dissimilar sheet metal parts can easily be joined using fasteners like bolts, screws, rivets, etc.

Brazing: Brazing is a process similar to welding that operates by melting a filler without melting the sheet metals.

Adhesives: Adhesives can be used to hold metal sheets together in conjunction with other joining methods

Advantages and Disadvantages of Sheet Metal Fabrication

As sheet metal fabrication covers a wide area of techniques and methods, the advantages and limitations will vary depending on the process used during fabrication.

Benefits:

i. Sheet metal fabrication is fast and can produce high-quality components.

i. A large number of processes are available with wide range of materials

ii. High strength to weight ratio for sheet metal fabricated parts.

Disadvantage:

i. Each fabrication process has their own limitations.

ii. High initial cost for set up of equipment and tools.

iii. Requirement of skilled labors for each process.

Sheet Metal Fabrication,Custom Sheet Metal Fabrication,Precision Sheet Metal Fabrication,Stainless Steel Sheet Metal Fabrication

Suzhou FCE precision electronics Co., LTD , https://www.sjfukeyifcesz.com