I feel that the soil has been weak in the past two years, what should I do?

First, the soil problem.

Due to the long-term single application of chemical fertilizers by farmers, the humus in the soil can not be replenished in time, coupled with improper farming methods and irrigation methods, it will cause soil problems, which will lead to soil water and fertilizer imbalance, crop yield and harvest, then it is necessary to improve the soil as soon as possible to prevent soil salinization or soil compaction.

2. Improve the soil.

In addition to reducing the damage to the land at the source, such as replacing chemical fertilizers with microbial organic fertilizers, we can also use mineral potassium fulvic acid to improve the problem soil. Mineral potassium fulvic acid is a black powdery substance soluble in water, which is the main component of soil conditioner mineral potassium fulvic acid, is a plant growth regulator, can promote plant growth, has an important role in drought resistance, can improve plant stress resistance, increase yield and improve quality.

Improving the soil in a timely manner, the effect of mineral potassium fulvic acid has always been visible, a soil conditioner widely praised by farmers, if your soil has a problem, you can apply mineral potassium fulvic acid to adjust.

Discharge cooling is another type of convection cooling. Unlike regenerative cooling, the coolant used for exhaust cooling absorbs heat to the thrust chamber and is discharged out of the combustion chamber instead of entering the combustion chamber to participate in combustion. Direct drain coolant reduces the thrust chamber specific impulse, so the coolant flow for drain cooling needs to be minimized while only using drain cooling at the outlet section of the nozzle that is relatively less heated.

There is also radiative cooling, in which the heat flow is transferred from the combustion products to the thrust chamber, and then the heat is radiated by the thrust chamber wall to the surrounding space. Radiative cooling is characterized by simplicity and small structural mass. It is mainly used in the extension section of large nozzles and the thrust chamber of small thrust engines using high-temperature resistant materials.

When cooling in the thrust chamber of the tissue, a relatively low temperature liquid or gas protective layer is established on the surface of the thrust chamber wall to reduce the heat flow to the thrust chamber wall, reduce the wall temperature, and achieve cooling. Internal cooling is mainly divided into three methods: internal cooling (shield cooling), membrane cooling and diaphoretic cooling of head tissues. After the internal cooling measures are adopted in the thrust chamber, the mixing ratio near the wall of the combustion chamber is different from the optimal mixing ratio in the central area (in most cases, the near-wall layer rich in fuel is used) due to the need to reduce the temperature of the protective layer, resulting in the uneven distribution of the mixing ratio along the cross-section of the combustion chamber, so that the combustion efficiency is reduced to a certain extent.

Membrane cooling is similar to shield cooling in that it cools the thrust chamber wall by establishing a uniform and stable coolant film or air film protective layer near the inner wall surface, except that the coolant used to establish the protective layer is not injected by the injector, but is supplied through a special cooling belt. The cooling band is generally arranged in a cross-section of the combustion chamber or the convergence section of the nozzle. There can be several cooling bands along the length of the combustion chamber.

In order to improve the stability of the membrane, the coolant often flows through the gaps or small holes in the cooling belts, and when sweating is used, the thrust chamber wall or part of the inner wall is made of porous material with a pore diameter of tens of microns. Porous materials are usually sintered with metal powders or pressed with metal mesh. In this case, the number of pores per unit area is increased by making the micropores in the material as evenly distributed as possible.

The liquid coolant penetrates into the inner wall, creating a protective film that reduces the density of the heat transferred to the wall. When the flow rate of liquid coolant used for sweat cooling is above a certain threshold, a liquid film is formed near the wall of the thrust chamber. When the coolant flow rate is below the critical flow, the inner wall temperature will be higher than the coolant boiling point at the current pressure, and some or all of the coolant will evaporate, forming an air film.

In addition to the above thermal protection, there are other thermal protection methods such as: ablation cooling, thermal insulation cooling, hot melt cooling and composite protection of chamber walls. 3. Thermal protection scheme of high enthalpy gas generator Based on the above methods and the actual situation, the thermal protection method of high enthalpy gas generator is obtained.

The combustion chamber of a high-enthalpy gas generator differs from that of a liquid rocket engine, eliminating the front thrust chamber part, making its structure simpler and more effective. Then, the thermal protection involved is the thermal protection part of the combustion chamber wall. As the fuel enters the combustion chamber, it quickly decomposes and releases large quantities.

Why is the soil becoming more and more barren with planting, and how to solve the problem of soil fertility?

For agricultural planting, good soil means benefits, but due to improper fertilization, it will lead to more and more soil problems, the common ones are:

1. The amount of fertilizer is large, and too much residue is left in the soil, which destroys the soil nutrient balance.

2. There is less organic matter, and the plant soil is insufficient to supplement after consuming organic matter, resulting in problems with soil aggregate structure and fertility.

3. There are few beneficial bacteria, although various bacterial groups can improve the air permeability of the soil, but the harmful bacteria are seriously harmful to the root system, which will lead to problems in the plant root system and cannot absorb nutrients well.

4. Unreasonable watering, drought or too much water will cause root rot and dead trees, which many people will ignore.

5. Unbalanced fertilization can not meet the balanced absorption and utilization of various elements by fruits, which is easy to cause soil stubble.

How many of the above five points do you know? In fact, the important thing in soil maintenance is the nutritional balance, we must supplement the appropriate fertilizer according to the characteristics of plant fertilizer, and recommend a multi-carbon fulvic acid liquid water-soluble fertilizer containing large and medium trace elements, organic and inorganic and large and medium trace elements balance supplement, rooting and fertilizer supplementation, simple and trouble-free.

Hope it works for you!