Variable Attenuator
CNI provides 3 kinds of variable attenuators for different application.The circular variable attenuator can make the optical density linearly varies around a 0°-270° circle for measuring Laser energy farthest. As for the square one, the optical density linearly varies across the length for measuring laser energy. Also the high power variable attenuator is available for customization.
Applications:
Detector of photon
Electronic image
Optical instrumentation
Specification
<1000 mW
Note: Dimension, wavelength range, OD or other request are available upon request.
â—†Square variable attenuator
Applications:
Electronic image
Detector of photon
Optical instrumentation
Specification
Note: Dimension, wavelength range, OD or other request are available upon request.
â—†Portable variable attenuator
Specifications:
Dimensions: Φ33 mm ×65 (L) mm
Wavelength: 400-1100 nm
(Other wavelengths can be customized)
Portable Impact Attenuator,Attenuator Amplifier,Attenuator Fixed,Optical Attenuator Pdf Changchun New Industries Optoelectronics Technology Co., Ltd. , https://www.lasersciences.com
The three major factors of fruit tree disease epidemics: 1 pathogens with strong pathogenicity; 2 a large number of susceptible hosts; 3 environmental conditions suitable for disease onset. With pathogens and susceptible hosts, appropriate environmental conditions often become the dominant factor in disease epidemics. The environmental conditions are divided into meteorological conditions, cultivation conditions and soil conditions, among which the meteorological conditions have the greatest impact. The environmental factors that affect the growth and development of fungi are temperature, humidity, light and pH, among which the former two are the most important ones. The temperature can affect the spore germination, mycelial growth, sporulation and dormancy. During cold winter temperatures, the fungus produces fruiting bodies and resting spores to adapt to adverse environments. In spring, the temperature rises. The dormant spores grow hyphae and begin a new cycle of infection. Water is the physiological substance of fungal metabolism. Without water, the fungus loses the basic conditions for vegetative reproduction. Most fungi require a relatively high relative humidity environment, especially in the formation of conidia, some fungi can not produce spores in dry water, can only produce germ tubes; some fungi in dry conditions Protoplasm condensation occurs. Light and pH can also affect the survival and reproduction of fungi, but far less than the temperature and humidity significantly. Many of the conidia of the fungus have pigments that are resistant to intense light, and some of the anti-drying cell walls can survive in high altitudes and travel long distances. Because most fungi can grow in the pH range of 3.0 to 9.0, the spread, infection, and epidemic of pathogens cannot be small due to the pH level.
In the orchard, the fungus lurks through dormancy at different sites. Spring temperatures continue to rise, providing suitable temperature conditions for the reproduction of fungi, but do not have the necessary humidity conditions. In the event of rain, the fungus quickly exerts his amazing ability to reproduce, proliferate a large number of offspring in a short period of time, in the orchard wantonly vicious, against fruit and tree branches and leaves, until it causes visible damage. Spring blooms in spring, and fruit trees begin to grow and develop. At this time, temperature conditions are also suitable for the growth of fungi. The main natural factor limiting their reproduction is moisture. Therefore, sooner or later, the severity of fungal diseases, etc. after spring temperature rises depends on the amount of rain in the spring and the amount of rainfall. After the spring temperature ceases to limit the growth of fungi, the earlier the rainfall and the greater the rainfall, the more serious the occurrence of fungal diseases in the orchard. In such a year, the prevention and control measures taken in production must be advanced accordingly so as not to cause any trouble. The spring rain in the orchard prevents disease and is based on the physiological characteristics of pathogenic fungi. To understand this, in the practice of fruit tree production, relative measures can be taken according to climatic conditions. In relatively dry years and regions in spring, orchards begin to concentrate on preventing disease most of the time in mid-May, but in early spring and early-spring, the time can be advanced to the end of April, even April and mid-April. Spring is the critical period for disease prevention in orchards. Whether the measures are appropriate or not will have a great impact on the orchard, so care must be taken in production.
â—†Circular variable attenuator
Material
BK7grade A optical glass, Fused silica
Optical Density Range
OD0-OD3
Outside Diameter
Φ54mm±0.25
Dimension
54*42*67mm
Linearity of Density
±5%@632.8nm
Coating
S1:Ni-Cr-Fe; S2:Boardband AR coating; incidence angle:0°-15°
Clear aperture
>80% diameter
Damage threshold
30W/cm2 CW
Active wavelength
400-1100 nm
Applicable power
Material
BK7grade A optical glass, Fused silica
Optical Density Range
OD0-OD2
Dimension
76.2*25.4*2.0mm
Linearity of Density
OD±5%
Coating
S1:Ni-Cr-Fe; S2:Boardband AR coating; incidence angle:0°-15°
Clear aperture
>80% diameter
Damage threshold
30W/cm2 CW
Active wavelength
400-1100 nm
Principles and methods of fruit tree disease prevention and control
Orchard prevention and pests are the same as the pests and they are all important technical links for fruit tree production. Whether or not disease prevention and treatment will benefit greatly affects the fruit production, quality, tree vigor, orchard uniformity and economic life. An orchard with an epidemic disease will inevitably lead to premature detachment of leaves, rotted branches, dead fruits and rotten fruits. Such an orchard is difficult to achieve high quality and high yield, and the economic benefits will not be too high. In orchards, the main pathogen that causes fruit tree disease is fungi. Fungi in the natural world are numerous, widely distributed, and have strong adaptability. They are also harmful to fruit trees. According to incomplete statistics, there are approximately 80 kinds of apple diseases in China, of which more than 70 diseases are caused by fungi, accounting for more than 90%. Relevant data also indicate that fungal diseases in diseases of pears, peaches, and grapes are also above 90%. It can be seen that the prevention of diseases in orchards is mainly the prevention and control of fungi. Therefore, it is very necessary to understand some fungal physiological knowledge.