Chapter 438: Rub Room-Temperature Superconducting Materials by Hand?

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

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

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

So the best way is to announce the end of get out of class before these "enthusiastic" students gather around.

Xu Chuan quickly slipped out of the teaching building along the corridor.

Just as he was about to return to his office, he bumped into the new president of Nanjing University, Tan Shaoyuan.

President Tan smiled and greeted him, walked over and asked: "Has Academician Xu finished the class? How do our students at Nanjing University feel?"

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

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

It must be said that Nanjing University's enrollment in the past two years has improved a lot, both in terms of scores and quality.

And among them, Xu Chuan has brought too much influence.

Nobel Prize winners, Fields Medal winners, chief designer of the National Controlled Nuclear Fusion Project, a series of reputations and achievements have made Nanjing University popular again and again.

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

In the past, almost all of these people went to Shuimu or Peking University, and at worst, they went to Fudan or Xiangdao. The Department of Mathematics at Nanjing University was basically not considered by them.

Xu Chuan smiled and said, "It is my honor to see my alma mater grow stronger."

After a slight pause, he continued, "By the way, President Tan, regarding teaching, I have something else I want to trouble the school with."

Hearing this, Tan Shaoyuan quickly replied, "Please go ahead, Academician Xu."

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

Hearing this, the President Tan in front of him nodded without hesitation and said, "That's no problem. I will immediately find someone to arrange for the statistics of student information after I go back."

"But regarding the students, do you have any questions? Requirements? "

Xu Chuan thought for a moment and said, "I take students here. I don't have the energy for undergraduates. It's enough to teach them normally. I mainly take graduate students and doctoral students."

"For graduate students, the postgraduate entrance examination score must be at least 380 points, and the professional score must not be less than 90 points. If there are excellent SCI papers and various scientific research project experience, the test score can be lowered. "

"As for doctoral students, the papers and scientific research project experience are mainly used as evaluation, and the grades are secondary. "

For him, taking students is not limited to a certain school. As long as he opens his mouth, he can basically recruit students from all over the country or even the world.

However, considering that this should be the first batch of students he takes after returning to China, Xu Chuan is still ready to give this opportunity to students from his alma mater.

Tan Shaoyuan nodded and said, "No problem, I will deal with it immediately after I go back. Do you have any other needs?"

Xu Chuan smiled and said, "No, for now, I'll trouble President Tan for this matter."

"Oh, what trouble, no trouble, no trouble, this is my job." Tan Shaoyuan waved his hand and said, "These students chosen by you are a blessing to them and Nanjing University."

Xu Chuan smiled, said goodbye to the newly appointed President Tan and returned to his office.

The room was empty, and Cai Peng didn't know where he went. He didn't care too much. He turned on the computer and began to continue to improve the aerospace engine concept that he had not finished last night.

Aerospace and aviation are two different concepts.

Although their meanings may sound similar, they are very different.

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

Aerospace only refers to the flight (navigation) activities of aircraft in the earth's atmosphere (air space), which 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 engines, and nuclear energy engines.

The most commonly used in various countries are liquid fuel rocket engines that use liquid fuel as aerospace engine fuel.

Although the thrust of solid fuel rockets is much higher than that of liquid fuel at the same weight, and the structure is also simpler. But the burning time of solid fuel is quite short, and ordinary launch vehicles can only last for two or three minutes.

In such a short time, it is almost impossible to send satellites or aerospace parts into space.

In addition, there are problems such as the inability to adjust thrust and unstable combustion. Solid fuel is still relatively rarely used in today's rockets.

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

That is, the specific impulse is too small.

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

The most common electromagnetic aerospace engines can easily achieve a specific impulse of more than one thousand seconds, and those electromagnetic engines with excellent performance can even achieve a specific impulse of more than five thousand seconds.

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

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

Just like the American space shuttle, 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 electromagnetic space engines, the weakness is that the thrust is much lower than that of fossil fuels.

The thrust of today's electromagnetic 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. As the electromagnetic space engine continues to work, the speed can also increase.

But if it is placed 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 space engines in the future after controllable nuclear fusion technology is realized.

But now, even he, as the 'Father of Controlled Nuclear Fusion', is having a headache over this.

Even if he can find a way to try his best to shrink the controllable nuclear fusion reactor, or use a miniaturized fission reactor, and then use it with a magnetic fluid generator to shoehorn it into the spacecraft, the thrust of the electromagnetic space engine is too weak and it is still a Huge trouble.

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

After recording some of the ideas in his mind, Xu Chuan planned to find experts from the aerospace industry in the future to see if he could realize a high-power electromagnetic aerospace engine system.

As for the method 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 significantly increase the specific impulse.

But if high-thrust electromagnetic aerospace engine technology and high-energy-density power supply equipment can really be realized, electric thrust technology has the potential to replace fossil fuel rockets with its advantage in specific impulse.

What's more important is battery life.

If nuclear fusion is used to power a spacecraft, in addition to being able to travel between the surface and space, the spacecraft will also have the ability to travel to distant places such as the moon and Mars.

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

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

After presiding over the Qixia Mountain Controlled Nuclear Fusion Project for more than two years, he almost left the world of mathematical physics.

Although he still had continuous contact with some former acquaintances, he was really not sure if anything else had happened in the mathematics and physics circles in the past two years.

While browsing through some events in the mathematical physics community over the past two years, a timely notification from Arxiv caught his eye.

[The first room temperature and normal pressure superconductor! 】

Seeing the pop-up box in the lower right corner, Xu Chuan was obviously stunned for a moment.

Room temperature superconducting materials?

what's the situation?

Quickly sliding the mouse with his right hand, he clicked on arxiv's push and entered this link.

"Abstract: The first room-temperature and normal-pressure superconductor, Subey Lee, Kim Ji-hoon, Kwon Yong-woon."

"We have successfully synthesized for the first time in the world a room temperature superconductor (Tc ≥ 400k, 127c) operating at ambient pressure with a modified lead apatite (KL-66) structure. The superconductivity of KL-66 is determined by the critical temperature ( Tc), zero resistivity, critical current (Ic), critical magnetic field (Hc), and the Meissner effect. The superconductivity of KL-66 results from slight structural distortion caused by slight volume shrinkage (0.48%). Not external factors such as temperature and pressure.”

"The shrinkage is caused by the substitution of copper 2+ lead ions in the 2+(2) lead phosphate insulating network and generates stress. It is simultaneously transferred to the Pb(1) of the cylinder, causing deformation of the cylinder interface, which occurs at the interface 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 the maintenance of 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 summary provided by arxiv was quickly reviewed by Xu Chuan, and at the same time, the corresponding paper had been downloaded.

Impatient, he quickly clicked on the downloaded paper.

Room temperature superconductivity?

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

With deep doubts in his heart, Xu Chuan quickly scanned the entire paper.

However, after reading the paper, all he could see in his eyes was the word 'outrageous' in capital letters.

Nothing else.

Just because this method of synthesizing KL-66 room temperature superconducting material simply refreshed his knowledge.

Step 1: Synthesize pyroclastic lead by chemical reaction. Mix lead oxide and lead sulfate powders in a ceramic crucible at a ratio of 50% each. Heat the mixed powder in a furnace at 725 degrees Celsius for 24 hours in the presence of air. During the heating process, the mixture undergoes a chemical reaction to produce pyroclastic lead.

Step 2: Synthesize cuprous phosphide crystals. Mix copper and phosphorus powders in a crucible in proportion. Seal the mixed powder in a 20 cm per gram thyristor with a vacuum of 10 to the -3 power torr. Heat the sealed tube containing the mixed powder in a furnace at 550 degrees Celsius for 48 hours, during which the mixture reacts and forms cuprous phosphide crystals.

Step 3: Grind the pyroclastic lead and cuprous phosphide crystals into powder, mix them in a crucible, and then seal them into a thyristor with a vacuum of 10 to the -3 power torr. Heat the sealed tube containing the mixed powder in a furnace at 925 degrees Celsius for 5-20 hours. During this process, the sulfur element 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, and the raw materials are also available everywhere.

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

Yes, it can be rubbed out by hand in the true sense.

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

The synthesis method and materials of this superconducting material are a bit too "cheap".

Of course, Xu Chuan did not deny that this room-temperature superconducting material called KL-66 was fake at the first time.

No matter how outrageous its synthesis process is, no matter how simple its synthesis process is, it requires rigorous and multiple experiments to confirm or disprove it.

And to be honest, in the field of materials, such similar things are not impossible to happen.

After all, relying on a piece of tape, one can stick together the world's most versatile material, 'graphene', and then win the Nobel Prize, which is also a real thing in history.

If you tell others about this kind of thing, others will only think that this is probably a novel written by a dog author who doesn't understand science.

After all, it is really too outrageous.

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

Sometimes, maybe you can get a 'koi' who is extremely lucky and knows nothing about materials and put it in the project team, and maybe it can bring you good luck, and in the blink of an eye, you can make some new materials that can make you worry-free for the rest of your life.

Materials, this is probably a field where all the luck is in the world, except for experience.