The optimum air temperature for spore capture by quantitative airborne spore traps is 20-25°C, and the daily average temperature is lower than 19°C or higher than 26°C, and the trapping volume is significantly reduced. Rainfall can promote the settlement of spores. Therefore, there is little catch on rainy days and the amount of sunny catches after rain increases sharply. The breeze is conducive to the spread of powdery mildew, and the amount of spores trapped by quantitative airborne spore traps increases. However, the spores of wind speeds below 0.2 m/s and above 3.0 m/s are significantly reduced.
The number of aerial spores is closely related to the condition of powdery mildew in the forest section. A quantitative airborne spore trap capture test showed that the number of aerial spores was positively correlated with the total incidence of forest segments after 5 to 7 days. When the number of spores captured on each slide reached 10 or so, the number of spores increased sharply, and the forest section became worse after 5-7 days.
The mastery of the occurrence and quantity dynamics of aerial spores during this period through quantitative airflow spore traps is a condition and basis for predicting the final condition and determining the first application period. Spores at the end of the winter and early spring when the gum trees began to draw leaves the rubber tree powdery mildew spores, with the gum tree leaf extraction rate increased simultaneously. Subsequently, as the temperature increased, the young leaves became old, the sporulation capacity decreased, and the aerial spores gradually decreased, so that the quantity of quantitative wind spore traps was also affected.
Carbon steel seamless steel pipe is a kind of long steel with hollow
section and no joints around. The steel pipe has a hollow cross-section
and is widely used as a pipeline for conveying fluids, such as pipelines
for conveying oil, natural gas, gas, water and some solid materials.
Compared with solid steel such as round steel, steel pipe has the same
bending and torsional strength and is lighter in weight. It is a kind of
economic cross-section steel, widely used in the manufacture of
structural parts and mechanical parts, such as oil drill pipe,
automobile transmission shaft, bicycle frame and steel scaffolding used
in construction.
The manufacture of ring parts with steel pipes
can improve the utilization rate of materials, simplify the
manufacturing process, save materials and processing time, such as
rolling bearing rings, jack sleeves, etc., which have been widely used
to manufacture steel pipes.
Steel pipe is an indispensable
material for all kinds of conventional weapons, and the barrel and
barrel are made of steel pipe. Steel pipes can be divided into round
pipes and special-shaped pipes according to the different shapes of the
cross-sectional area. Because the circular surface volume is the largest
under the condition of equal circumference, more fluid can be
transported with circular tubes. In addition, when the annular section
is subjected to internal or external radial pressure, the force is more
uniform, so the vast majority of steel pipes are round pipes.
The use of steel pipe to manufacture ring parts can improve the
utilization rate of materials, simplify the manufacturing process, save
materials and processing hours, such as rolling bearing rings, jack
sleeves, etc., currently has been widely used to manufacture steel pipes
carbon steel black pipe,seamless carbon steel pipe,low carbon steel pipe,carbon steel welded pipe
Shandong Fengbao Metal Products CO.,LTD. , https://www.fengbaosteels.com