Great Country Academician

After answering a few questions, the bell rang for the end of get out of class.

Hearing the ringing of the bell, Xu Chuan quickly picked up the textbook from the podium, and then quickly slipped out of the classroom.

He is quite experienced in this area. After all, he was blocked once before in class, and it took him a long time to get out.

So the best way is to directly announce the end of get out of class and leave before these 'enthusiastic' students gather around.

Following the corridor, Xu Chuan quickly slipped out of the teaching building.

Just as he was about to go back to his office, he bumped into Tan Shaoyuan, the new president of Nantah University.

Principal Tan greeted him with a smile, walked over and asked, "Academician Xu has finished his class? How do our Nantah students feel?"

Xu Chuan smiled and said, "Very good, these students are very serious and enthusiastic."

Tan Shaoyuan smiled and said, "It's all thanks to you, Academician Xu. With you here, the scores and quality of our Nantah University's enrollment in the past two years have been getting better every year."

I have to say that NTU's enrollment in the past two years has improved a lot, both in terms of score and quality.

Among them, Xu Chuan had too much influence.

A Nobel Prize winner, Fields Medal winner, chief designer of the National Controllable Nuclear Fusion Project, a series of fame and achievements have made Nantah University go out of the circle again and again.

Including the Department of Mathematics, which was originally mediocre and even a bit stretched in colleges and universities, has now taken off. There are even many mathematics competition students who have chosen to apply for Nanjing University.

In the past, almost all of these students went to Mizuki or Peking University, and no matter how bad it was, they would go to Fudan or Xiangdao. The Department of Mathematics of Nantah University was basically not in their consideration.

Xu Chuan smiled and said, "It's my honor that my alma mater grows strong."

After a slight pause, he continued: "By the way, let's talk about the principal. Regarding teaching, I still have something to trouble the school."

Hearing this, Tan Shaoyuan quickly replied: "Academician Xu, please speak."

Xu Chuan: "I'm going to take a few students here, and I want to see if there are any suitable ones. Can the school help us to screen first?"

Hearing this, the Principal Tan in front of him nodded without hesitation and said, "That's no problem. I'll find someone to arrange to count the student information as soon as I get back here."

"But regarding the students, do you have any requirements here?"

Xu Chuan thought for a while, and said: "I take students here, undergraduates are fine, I don't have the energy, it's enough to teach them usually. I mainly accept graduate students and doctoral students."

"For graduate students, the postgraduate entrance examination score should be at least 380 points, and the professional score should not be lower than 90 points. If you have excellent SCI papers and experience in various scientific research projects, the test score can be lowered."

"As for doctoral students, the evaluation is mainly based on the thesis and scientific research project experience, and the grades are second."

For him, the matter of bringing students is no longer limited to a certain school. Students from all over the country and even the whole world can basically be recruited as long as he asks.

However, considering that this should be the first batch of students he brought in after returning to China, Xu Chuan still plans to give this opportunity to the students of his alma mater first.

Tan Shaoyuan nodded, and said: "No problem, I will deal with it immediately after returning here, do you have any other needs?"

Xu Chuan smiled and said, "Not for the time being, then I will trouble the principal with this matter."

"Hey, what's the trouble, no trouble, no trouble, this is my job." Tan Shaoyuan waved his hand and said, "It's the students you selected, but they are the blessings of Nantah University."

Xu Chuan smiled, bid farewell to the new Principal Tan and returned to his office.

The room was empty, Cai Peng didn't know where he went, and he didn't care too much. He turned on the computer and began to continue to perfect the idea of ​​the space engine that he hadn't finished last night.

Aerospace and aviation are two different concepts.

Although they may sound similar in meaning, there is a big difference.

Aerospace refers to the general term for various activities of entering, exploring, developing and utilizing space and celestial bodies other than the earth. The engine needs to work in an oxygen-free environment.

Aviation only refers to the flight (navigation) activities of aircraft in the earth's atmosphere (air space), and generally requires oxygen in the atmosphere as fuel assistance.

The two are not the same thing.

At present, aerospace engines are divided into four types: solid fuel rocket engines, liquid fuel rocket engines, electromagnetic force engines, and nuclear energy engines.

Countries use relatively common liquid fuel rocket engines, generally liquid fuel as aerospace engine fuel.

Although the thrust of solid fuel rockets is much higher than that of liquid fuels at the same weight, the structure is also simpler. But the burning time of solid fuel is quite short, and a general launch vehicle can last for two to three minutes.

In such a short period of time, it is almost impossible to send satellites or space objects into space.

In addition, the thrust cannot be adjusted, and the combustion is unstable. Solid fuel is still relatively seldom used in today's rockets.

Of course, in Xu Chuan's view, both solid-fuel rockets and liquid-fuel rockets have an unavoidable shortcoming.

That is, the specific impulse value is too small.

Compared with the electromagnetic force aerospace engine, the specific impulse value of the fossil fuel engine will not exceed 500 seconds at the highest.

The most common electromagnetic space engine can easily achieve a specific impulse value of more than 1,000 seconds, and those electromagnetic engines with excellent performance can even achieve a specific impulse value of more than 5,000 seconds.

The so-called specific impulse, if described in technical terms, refers to a measure of the efficiency of a reactive mass engine (a rocket using propellant or a jet engine using fuel) to generate thrust.

Of course, if you want to understand it simply, it can be understood as "the time that the rocket engine can last for one kilogram of thrust generated by one kilogram of propellant.

Just like the space shuttle in the United States, its main engine propellant is generally liquid oxygen/liquid hydrogen, and the vacuum specific impulse is 452.3 seconds.

But behind the high specific impulse of the electromagnetic space engine, the weakness is that it is far lower than the thrust of fossil fuels.

The thrust of today's electromagnetic force aerospace engines is generally around micronewtons or millinewtons.

This level of thrust is indeed feasible in space in a vacuum state. After all, there is no resistance. With the continuous work of the electromagnetic space engine, the speed can also be increased.

But if you put it in the atmosphere

It is no exaggeration to say that it does not even have the ability to send an egg into space.

No one doubts the potential of electromagnetic force aerospace engines in the future after the realization of controllable nuclear fusion technology.

But now, even as the 'father of controllable nuclear fusion', he still has a lot of headaches.

Even if he can try his best to shrink the controllable nuclear fusion reactor, or use a miniaturized fission reactor, and then use the magnetic fluid generator set to force it onto the spacecraft, but the thrust of the electromagnetic space engine is too weak, it is still a problem. Huge trouble.

"Perhaps, in this regard, I should refer to the opinions of experts in the aerospace field. After all, I am not a person in the professional field."

After recording some ideas in his mind, Xu Chuan planned to find experts in aerospace after a while to see if he could realize a high-power electromagnetic space engine system.

As for the way of fossil fuel propulsion, it has been thrown out of his consideration anyway.

After all, chemical fuel rockets have now come to an end, and it is almost impossible to greatly increase the specific impulse.

However, if high-thrust electromagnetic space engine technology and high-energy-density power supply equipment can be realized, the advantages of electric propulsion technology in specific impulse have the potential to replace fossil fuel rockets.

More importantly, it is battery life.

If nuclear fusion is used to power the spacecraft, in addition to being able to go back and forth between the surface and space, the spacecraft will have the ability to go to the moon, Mars and other distant places.

Even, with sufficient energy supply, the speed of the spacecraft can be increased several times, greatly shortening the time required to go back and forth between the moon and Mars.

After recording some thoughts in his mind, Xu Chuan opened the browser and searched and browsed some things that happened in the scientific world in the past two years.

He has presided over the controllable nuclear fusion project of Qixia Mountain for more than two years, and he is almost out of the world of mathematical physics.

Although he still keeps in touch with some former acquaintances one after another, he really doesn't know if anything extra has happened in the world of mathematics and physics in the past two years.

While browsing through some events in the field of mathematics and physics in the past two years, a timely push from Arxiv came into his eyes.

[The first room temperature and atmospheric pressure superconductor! 】

Seeing the bullet box in the lower right corner, Xu Chuan was obviously taken aback.

Room temperature superconducting materials?

what's the situation?

With a quick swipe of the mouse with his right hand, he clicked on the arxiv push and entered this link.

"Abstract: The first room-temperature and atmospheric-pressure superconductor, Subei Lee, Kim Ji-hoon, Kwon Young-yun."

"For the first time in the world, we have successfully synthesized a room temperature superconductor (Tc ≥ 400k, 127c) working with a modified lead apatite (KL-66) structure at ambient pressure. The superconductivity of KL-66 is achieved by the critical temperature ( Tc), zero resistivity, critical current (Ic), critical magnetic field (Hc), and Meissner effect. The superconductivity of KL-66 comes from the tiny structural distortion caused by slight volume shrinkage (0.48%), while It is not external factors such as temperature and pressure."

"Its shrinkage is caused by the substitution of 2+ lead 2+(2) lead phosphate ions in the insulating network of copper and creates stress. It is simultaneously transferred to the Pb(1 ) of the cylinder, causing deformation of the cylinder interface, which in the interface A superconducting quantum well (sqw) is produced in the . The heat capacity results show that the new model is suitable for explaining the superconductivity of KL-66."

"The unique structure of KL-66 allows to maintain a tiny twisted structure in the interface, which is the most important factor for KL-66 to maintain and exhibit superconductivity at room temperature and ambient pressure"

The short abstract provided by arxiv quickly passed through Xu Chuan's eyes, and at the same time, the corresponding paper has also been downloaded.

Can't wait, he quickly clicked on the downloaded paper.

Room temperature superconductivity?

I have never heard of South Korea's outstanding research in this area in my previous life. Why did this suddenly appear?

With strong doubts in his heart, Xu Chuan quickly browsed through the entire paper.

However, after reading the thesis, all he had in his eyes were two capitalized 'outrageous'.

without him.

Just because of the synthesis method of this KL-66 room temperature superconducting material, his cognition has been refreshed.

The first step is to synthesize chalkenite through chemical reaction. The lead oxide and lead sulfate powders were uniformly mixed in a ceramic crucible at a ratio of 50% each. The mixed powder was heated in a furnace at 725 degrees Celsius for 24 hours in the presence of air. During heating, the mixture undergoes a chemical reaction, producing chalcopyrite.

The second step is to synthesize cuprous phosphide crystals. Mix copper and phosphorus powders in proportion in a crucible. Seal the mixed powder in a 20 cm per gram thyristor with a vacuum of 10 torr. The sealed tube containing the mixed powder was heated in a furnace at 550 degrees Celsius for 48 hours, during which time the mixture reacted and formed cuprous phosphide crystals.

The third step is to grind chalcopyrite and cuprous phosphide crystals into powder, mix them in a crucible, and then seal them into a thyristor with a vacuum of 10-3 torr. Heat the sealed tube containing the mixed powder in a furnace at 925°C for 5-20 hours. During this process, the elemental sulfur in the lead sulfate evaporates during the reaction, and the mixture reacts and transforms into the final material, KL-66.

Three steps, the synthesis process is extremely simple, not to mention the raw materials can be found everywhere.

According to the method and steps given in the paper, the synthesis method of this new material is undoubtedly similar to 'hand rubbing'.

That's right, you can rub it out by rubbing your hands in the true sense.

If this method can really synthesize room-temperature superconducting materials, then even he can't help but wonder whether the technology tree that humans have made in the field of materials before is all crooked.

The synthesis method of this superconducting material, as well as the material, are a bit too 'cheap'.

Of course, Xu Chuan did not immediately deny that this room-temperature superconducting material named KL-66 was fake.

No matter how outrageous its synthesis process is, no matter how crude its synthesis process is, it needs rigorous and many experiments to prove or deny it.

And to be honest, in the field of materials, this kind of thing is not impossible.

After all, relying on a piece of adhesive tape, the world's most versatile material 'graphene' can be glued, and then won the Nobel Prize, which is also a real thing in history.

When this kind of thing is said, others will only think that this is a novel written by some dog author who does not understand science.

After all, it is a bit too outrageous.

The same is true for the KL-66 material in South Korea. Although it seems that the synthesis process is a bit outrageous and crude, it is not impossible in the field of materials.

Sometimes, maybe you get a 'koi' who is so lucky that you don't know anything about materials and put it in the project team, maybe it can bring you good luck, and in the blink of an eye, you can come up with something that can make you New materials for the second half of life to live comfortably.

Materials, this is probably a domain that is all about Ouhuang, regardless of experience.