According to the results of years of experiments, celery production in protected areas, due to the obstruction of gas exchange inside and outside the shed, the carbon dioxide concentration in the greenhouse decreases with the photosynthesis of celery, especially the carbon dioxide concentration is lower from 9 am to 1 pm. In order to increase the photosynthesis of celery and promote the growth and development of celery, the application of carbon dioxide gas fertilizer in the protected area is a technical measure with significant economic benefits. After the application of carbon dioxide can promote the development of celery roots, enhance photosynthetic capacity, make plants robust, strong resistance, per 667 square meters can increase production of more than 1,000 kilograms. There are three specific ways of application:
Chemical reaction method. That is, carbon dioxide and strong acid react to produce carbon dioxide, so that the carbon dioxide in the protected place reaches a suitable concentration. In production, dilute sulfuric acid and ammonium bicarbonate are generally used to react to produce ammonium sulfate, water and carbon dioxide. The specific approach is: take 10 to 20 points in every 667 square meters of shed, dig a hole of 30 centimeters in diameter and 20 centimeters in depth at each point, or suspend the used plastic bottles or bowls from the ground with a rope. About 1 meter in the air. In order to prevent the ammonium bicarbonate from being added into the sulfuric acid reaction, the foam generated by the reaction may splash and damage the operators and the stems and leaves of the celery. An acid-resistant pot or an open plastic bucket may be used. First, 3 parts of fresh water may be added, and then 1 part of concentrated Sulphuric acid is slowly added to the water along the wall, stirring constantly, and cooling is used. The sulfuric acid for the reaction may be charged in the container for 3 days at a time, and ammonium bicarbonate may be added thereto in the required amount every day. The amount of sulfuric acid put into each point can be determined according to the control area. Ammonium bicarbonate was added half an hour after sunrise each day, while stirring, and the shield was sealed for 2 hours before releasing the air. From the start of easing seedlings, it can be applied continuously for 40 to 60 days, and it should be parked on rainy days. Every 1 to 2 kilograms of carbon dioxide is added once per 667 square meters of protected land, which means that there is a significant increase in production, and its concentration must not exceed 1500 ppm. Daily required amount of ammonium bicarbonate (g) = Volume of protected space (cubic meters) Applied carbon dioxide concentration (ppm) 0.0036; Daily required amount of sulfuric acid (g) = Daily required amount of ammonium bicarbonate (g) 0.62 .
Apply liquid carbon dioxide. The carbon dioxide gas is compressed into a cylinder (available on the market) and put directly into the protected area. Two parallel vent pipes are generally set in the protected area, one is about 80 centimeters from the ground, and the other is 10 to 20 centimeters from the roof. Every 60 centimeters in the pipe is used to drill a hole with a diameter of 0.3 centimeters. It is clear at 8:30 am on sunny days. Relieve air once at 11:30 and add about 2kg of carbon dioxide. In 1 hour, the carbon dioxide concentration in the shed can reach 1200 to 1500 ppm. Using this method, labor intensity is low, but the cost is high.
Burning fuel produces carbon dioxide. The use of fuels such as kerosene, coal gas, coal, etc., is easier to source and easy to use. It can increase the concentration of carbon dioxide and raise the temperature. However, the concentration of carbon dioxide gas is not easy to control, and carbon monoxide, sulfur dioxide and other harmful gases are often associated with combustion. .
The RNA purification kit is used to purify and recover RNA molecules transcribed in vitro and total RNA extracted from various materials, which can effectively remove contaminating impurities in RNA samples. The recovery rate of this product can reach 80%, and the OD260/OD280 ratio of the obtained RNA is generally about 2.0, which can be directly used in subsequent sensitive experiments (such as microarray analysis, fluorescence RT-PCR, etc.). With the deepening of transcriptomics, the complexity of RNA types, expression regulation and functions is far beyond our imagination.
Removing ribosomal RNAs that account for more than 80% helps to focus sequencing on less abundant but informative RNAs. At present, the removal of rRNA is mainly through the combined use of probe and RNase H. The processed RNA will be mixed with many digestion products, enzymes and ions, which is not conducive to the subsequent construction of RNA library. Take the Columnar RNA Purification Kit as an example. Trizol is a ready-to-use reagent that can be used to purify total RNA from tissues and cells. This is a single-phase solution of phenol and guanidine isothiocyanate that facilitates lysis of tissues and cells, inhibiting RNases to maintain RNA integrity.
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