Chapter 859: Can the desert...be turned into fertile farmland?
After Li Nianheng’s question, the entire conference room finally returned to the relatively serious atmosphere at the beginning.
Lu Jinhui also switched to another PPT immediately.
“The samples from the Badain Jaran Desert are also divided into three groups: A, B, and C according to the distribution of sampling points. The characteristics of the three groups of samples are consistent. Group B is the southern part of the desert. The part close to the northern foot of the Qilian Mountains and the Ayou Banner has the most obvious characteristics, so we will use it as an example to explain below..."
"Relatively speaking, the situation of Badain Jaran Group B is different from that of Tengger A. The groups show different directions, and their chemical properties, bulk density, water holding capacity, saturated hydraulic conductivity, porosity and other hydraulic properties are similar to those of ordinary deserts, but the particle conditions are quite different from typical desert sands.”
He said and posted two more photos similar to the ones before.
It’s just that the objects of comparison this time are slightly different.
It can be seen that the Group B gravel samples on the left are very different in appearance.
At least it doesn’t look so round.
However, due to inappropriate chemical properties and porosity, it cannot replace the role of river sand.
“Through the same effective stress test as in the previous step, we found that the normal contact pressure and tangential restraining force of Badain Jaran Group B were significantly better than those of Tengger Group A when there were obvious constraints on the sides of the sand column. Other samples are even better than some river sand..."
"..."
The introduction quickly ended.
This time, everyone’s feedback seemed much colder.
The main thing is... I really can't think of the significance of this feature for a while.
After all, the use of sand is relatively narrow.
After excluding construction materials, which is the most likely direction to produce results, there seems to be only one semiconductor industry left...
Theoretically, it can be used to refine silicon.
But semiconductor-grade sand raw materials need to be relatively pure and have good porosity.
However, a lot of magnesium, manganese, and calcium can be detected in the ingredients of Badain Jaran Group B, especially the latter two, which are harmful ingredients to the silicon industry, and the sand is relatively compact. , and is not conducive to subsequent steps.
All in all, it looks a bit tasteless.
However, Li Nianheng was still quite excited.
Because such distinctive geological conditions - whether meaningful or not, are very suitable for verifying SAR signals.
"Professor Chang, Professor Meng, look, after we go back, can we start to summarize the patterns through these data?"
Meng Zhenyuan, who had been an audience just now, nodded:
"At least, we can now clearly see that the results obtained after data dimensionality reduction can indeed correspond to the geological conditions of different characteristics..."
Although the specific design of data extraction and processing algorithms The person is Chang Haonan, but the starting point of everything, that is, the subject of remote sensing data analysis, still bears the name of Meng Zhenyuan.
Even according to the most stringent conditions, at this point, the project can be considered complete.
"Professor Chang, what do you mean..."
Li Nianheng never heard Chang Haonan's response, so he turned to look at him.
But he found that Chang Haonan was holding his chin with one hand, looking down in thought, but never spoke.
There was a brief silence.
"Then...if all comrades have no other questions, the preliminary situation of the two desert areas will be introduced here. The following should be the three areas at the northern foot of the Tianshan Mountains. Please..."
As Zhai Mingguo, who acted as the temporary host, opened his mouth, Lu Jinhui, who was already very satisfied with the presentation of his results, also began to pack his things and prepare to give up the podium to the next person.
However, at this moment, Chang Haonan suddenly raised his head again:
"Wait!"
Lu Jinhui's action of putting away the computer paused momentarily, and then plugged back the signal cable that had been unplugged.
The projector lights up again.
"Professor Chang, please tell me."
"In addition to the normal contact pressure and tangential binding force, have you measured the restraining tension and restraining moment of this set of samples?"
Chang Haonan pointed at the curtain.
"The restraining force and restraining moment..."
This somewhat awkward question stunned Lu Jinhui, and then he shook his head in confusion:
"No..." In fact, stress testing itself is not an item in the standard testing process.
As for the normal contact pressure and tangential restraining force that he had already done, he filled them in with reference to papers on geotechnical engineering.
Looking at Lu Jinhui’s doubtful eyes on the stage, Chang Haonan organized his language and then explained:
“If this group of desert sand samples can provide normal direction at the same time under certain conditions, Contact pressure, tangential binding force..."
Having said this, he felt that describing it in words alone might be a bit feeble, so he looked at Zhai Mingguo next to him:
"Researcher Zhai, what are we doing here? Is there a blackboard? ”
The latter looked around and found that there was indeed only the piece on the wall in the conference room.
But it was blocked by the curtain.
However, it is Chang Haonan’s request after all, so it must still be met.
Within a few minutes, two staff members walked in from the door pushing a small blackboard on a pulley.
Chang Haonan was not polite and stood up directly and came to the podium.
This action made Lu Jinhui confused about where he should be for a moment.
"Oh... you go down first."
Chang Haonan said.
Then he turned around, picked up the chalk and quickly drew dozens of small balls on the blackboard, while explaining:
"Comrades, look."
“Assuming that sand particles have normal contact pressure, tangential restraining force, restraining tension, and restraining moment at the same time, and can also ensure a certain following degree of freedom, it means that each particle can not only generate restraining reaction force but also react along the restraining force. The direction of the force causes displacement. "
"And if we enlarge the viewing angle, the sand particles in the entire space will have this characteristic, and let them be in a rheological state in some way. , then any particle can contact another particle in any direction to generate constraints. Even if the two particles separate, as long as the contact can be restored, this constraint can be shaped again..."
With the According to his analysis, the blackboard was gradually filled with white, yellow, and blue chalk marks, and even the small round balls originally drawn on it were difficult to see clearly.
In fact, this kind of analysis should be carried out on a computer in a form similar to molecular dynamics simulation.
It’s just that Chang Haonan just brainstormed, so now he can only present it on the blackboard.
Fortunately, there were still people below who understood what he meant.
“That is to say, if we can use some method to transform sand... uh... this type of sand from a discrete state into a rheological state, then the original sand bodies separated one by one will be It will transform into an omnidirectionally binding one that can self-repair to a certain extent..."
Zhai Mingguo has obviously grasped the key points of Chang Haonan's introduction.
It’s just that there is really no way to express it more vividly.
At this time, Lu Jinhui, who had returned to his seat not long ago, added just the right sentence:
"The properties will be similar to... No, it will be basically equivalent to soil?"
As soon as these words came out, everyone in the entire conference room suddenly understood.
Although the chemical composition of this soil converted from sand bodies is still different from real soil, its physical properties already have the ability to store water, nutrients and air.
That's enough.
As long as the ecological-mechanical properties can be maintained for a long time, the missing things can be made up by artificial means such as precipitation or fertilization.
And if we take a longer-term view...
It can even be said that deserts with sand body characteristics close to those of Badain Jaran Group B have the opportunity to transform into soil with conditions for large-scale production!
For China, which is facing severe land degradation and sandstorms, this can be said to be a blessing in disguise after a long drought.
Especially in the central and western parts of Mongolia Province and the central part of Longyuan Province, the terrain is actually slopes and plains that are easy to cultivate on a large scale. However, the land conditions are too poor to meet the demand.
If these parts could really be transformed into farmland...
Everyone looked at each other.
Don’t dare to think about it.
I dare not even think about it.
(End of this chapter)