The light intensity is the intensity of sunlight on the surface of the object. The intensity of light depends on the strength of visible light. Visible light is the natural light we see everyday, with a wavelength between 400nm and 800nm ​​(probably). Ultraviolet light with a wavelength of less than 400 nm is harmful to humans and plants. Infrared light with a wavelength of more than 800 nm is now found to have many functions and can be used in various detection instruments such as near-infrared. Fast fruit analyzer, near-infrared soil nutrient tester, etc. Under natural conditions, the light intensity varies greatly due to different weather conditions, seasonal changes, and planting degrees. Changes in light intensity can be divided into three major categories: day and night, summer and winter, and sunny and rainy days. Cloudy light intensity is small, sunny is large. During the day, morning and evening light intensity is small, but it is large at noon. During the year, the light intensity in winter is small, and it is large in summer. When the plant density is large, the light intensity is small, and when the plant density is small, the light intensity is large. Therefore, in the natural environment, it is difficult to grasp the light intensity parameter, but if we need a corresponding relationship between a plant and the light, we can try to use the light box to control the light time and light intensity and other related parameters, and then Plant growth is recorded. In this way, the relative relationship between plant growth and light can be well established. Of course, we can also use artificial climate box, which can control multiple parameters such as temperature, humidity, light intensity and time. It is well-suited to study the relationship between multi-parameter environments and plant growth.
At the same time, the intensity of light has regional and elevation changes. The light intensity is greatest in the equatorial region and gradually decreases with increasing latitude. For example, in low-latitude tropical desert areas, the annual light intensity is 200 kcal (8.37×105 joules)/cm 2 or more; in the high-altitude Arctic regions, the annual light intensity does not exceed 70 kcal (2.93×105 joules). / cm 2. In southern China, located in the mid-latitudes, the annual light intensity is about 120 kcal (5.02 x 105 joules)/cm2 (Figure 2-15). The light intensity also increases with altitude. For example, at an altitude of 1000 meters, 70% of the total incident sunlight energy can be obtained, while at a sea level of 0 meters, only 50% can be obtained. In addition, the slope and slope of the mountain also have a great influence on the light intensity. In the temperate regions of the northern hemisphere, the southern slope of the mountain receives more light than the plains, while the plains receive more light than the northern slope. With the increase of latitude, the slope of maximum annual illumination on the southern slope also increases. However, on the northern slope, the slope is lighter, regardless of the latitude. The higher latitudes of the southern slope provide more solar energy than the northern slopes of the lower latitudes, so the southern heat-loving crops can be transplanted to the northern slopes of the north.
Light intensity also changes within an ecosystem. In general, the light intensity will gradually weaken from top to bottom in the ecosystem. Because the canopy absorbs a large amount of solar energy and the use of solar energy by the lower plants is limited, the vertical stratification of an ecosystem is both It depends on the community itself and also on the amount of solar energy received. In aquatic ecosystems, the light intensity will decrease rapidly as the water depth increases. Water is effective in absorbing and reflecting light. In a clear, static body of water, only about 50% of the light reaching the surface of a water body can reach a depth of 15 meters. If water is flowing and turbid, it can reach this depth. The amount of light is much less, which is a great limitation on the photosynthesis of plants in the water.
The growth of plants is achieved through the storage of organic matter through photosynthesis. Therefore, the light intensity has a great influence on the growth and development of plants, and it directly affects the strength of photosynthesis of plants. There is no fixed proportion relationship between light intensity and plant photosynthesis, but within a certain range of light intensity, under the condition that other conditions are met, the intensity of photosynthesis increases correspondingly with the increase of light intensity. However, when the light intensity exceeds the saturation point of the light, the light intensity increases again and the photosynthesis intensity does not increase. When the light intensity is too strong, it will destroy the protoplasm, cause decomposition of chlorophyll, or make the cells lose water too much and make the stomata close, causing the photosynthesis to weaken or even stop. When the light intensity is weak, the photosynthesis of the plant produces less organic matter than the respiration, and the plant will stop growing. Only when the light intensity can meet the requirements of photosynthesis can plants grow and develop normally.
Vaccines In Vial
Influenza Vaccine, Live, Nasal, Freeze-dried Exclusively authorized by the WHO in China
Influenza Vaccine, Live, Nasal, Freeze-dried is a cooperative project with the WHO, which has been included in Global Action Plan for Influenza Vaccines (GAP)[1]. Hundreds of millions of doses have been used in the world, and Changchun BCHT Biotechnology Co. has the exclusive right of production and
operation in China.
Intranasal spray administration, no injection and no pain
The vaccine is inoculated by nasal spray, equipped with nasal spray device, and only needs to spray once a year in two nostrils to prevent influenza.
Mucosal immunity + Cellular immunity + Humoral immunity
After influenza virus attacks human body, it widely exists in nasal cavity, respiratory tract and other mucosal parts, as well as in body fluids and cells.
Vaccination of Influenza Vaccine, Live, Nasal, Freeze-dried can quickly stimulate the triple immune response of human body, and carry out defense
against viruses in different parts:
·Intranasal administration can produce mucosal immunity (IgA antibody), which forms the first immune defense line in the nasal cavity.
·Produce humoral immunity (IgG antibody) to remove influenza virus from body fluids.
·Produce cellular immunity (T cells) to remove influenza virus from cells
3+N More extensive protection
The production strains are recommended and supplied by the WHO every year.
The vaccine can not only effectively resist the vaccine strain, but also produce cross immunity to other subtypes of influenza virus.
Produced with SPF embryonated eggs
SPF
The chick embryos for vaccine production comes from SPF (specific pathogen free) chicken flocks, so the risk of exogenous pathogenic microorganism
pollution is excluded.
Free of inactivator, split agent and preservative
Influenza Vaccine Live Manufactured,Influenza Vaccines In Vial,Flu Vaccine In Vial,Influenza Vaccine While Having Flu
Changchun BCHT Biotechnology Co. , https://www.ccbcht.net
![<?echo $_SERVER['SERVER_NAME'];?>](/template/twentyseventeen/skin/images/header.jpg)