Great Country Academician

After listening to the plan of the person in charge on the stage, Xu Chuan looked at Qin Anguo who was sitting beside him with a strange expression.

The mass catapult, the Nantianmen project, and the space carrier are all things he talked to Wen Yuanhang a week ago.

I didn't expect to be pulled up today as a publicity.

Noticing Xu Chuan's gaze, Qin Anguo turned around and smiled at him, saying, "I also have to thank Academician Xu for your proposal. After Comrade Wen Yuanhang came back, he reported these directions and developments."

"After discussing in the internal meeting of Shumen, everyone felt that your suggestion was quite good, so they made a more detailed plan and used it in today's exchange meeting."

"After all, today's exchange meeting is open to the public, coupled with such a large-scale report, no matter what, it can attract some attention from the United States."

Xu Chuan rubbed his chin, thought for a while, and said, "To be honest, I think the plan you made may be really feasible. Things like mass catapults are theoretically possible. .”

Hearing this, Qin Anguo asked curiously, "How?"

Xu Chuan smiled and explained: "If it's just a simple manned spaceflight and lunar exploration project, there is really no need to build a large mass catapult."

"After all, the spacecraft needed to carry out a manned spaceflight and lunar exploration project will theoretically not exceed 100 tons."

"Even if we can't directly send a 100-ton spacecraft into the sky at one time, we can do it several times, and it won't cost too much money."

"But if you want to carry out large-scale lunar exploration, fire detection, and even establish a permanent scientific research and living foundation on it, a simple and lower-cost delivery method is quite necessary."

"From a long-term perspective, building a large mass accelerator is still a good choice."

Qin Anguo thought for a while and asked, "How much money and time would it take to build such a project? Can the current technology do it?"

Hearing this, Xu Chuan thought for a while, and said, "Mass projectors are generally composed of giant electromagnetic rails, and may also be composed of coils, vacuum pipes, and power supply systems."

"And no matter which one of these three has huge engineering difficulties, the electromagnetic rail or coil is best composed of a superconductor, and its huge superconductor requirements and corresponding low temperature requirements are almost unacceptable at present."

"However, as long as superconducting materials are further developed, theoretically this shortcoming can also be solved."

"Secondly, the engineering difficulty of the vacuum super pipeline several kilometers vertical also exists, but this can be built with the help of mountains like Mount Everest. With the structural support of the mountain, this is not the most important."

"As for the energy supply problem, after the controllable fusion technology is solved, electric energy is the easiest problem to solve."

"So in theory, it is indeed possible."

"As for the funding, I did a simple calculation and estimated that this project should start at trillions of RMB."

"But the advantage is that after it is completed, the price of each launch is quite low. With this kind of thing, space activities can be carried out on a large scale in the future."

"If you're interested, I can get someone to do a planning and budget plan for you when I go back."

Hearing the budget revealed by Xu Chuan, Qin Anguo smiled wryly, shook his head and said, "Trillions, it's impossible, at least not now. It's impossible for the Development Committee to pass a project with a budget of this level."

If it is controllable nuclear fusion, perhaps when we see hope, such as the demonstration reactor, this level of investment can still pass. After all, Huaguo is extremely hungry for energy, and it only spends on fossil fuel imports every year. The amount far exceeds this figure.

But aerospace engineering is almost impossible.

Even if the country can spare so much money, it is impossible to invest it in this kind of project. Is it not good to mine resources on the earth? Must go to space?

Why, the iron in space is better than the iron on the earth?

Xu Chuan smiled and said, "Actually, I'm more optimistic about repairing on the moon than on the earth."

"For digging the third-class helium deposits on the moon, because of the low gravity and airless environment, it does not require a large-scale mass projector to throw large-mass items to the earth."

Qin Anguo thought for a while, then smiled and said: "This idea is quite special, I suggest to study it after I go back."

The two chatted, and the exchange meeting on the stage came to an end.

Aside from the representatives from the Academy of Sciences and the Science and Technology Department, representatives of major aerospace companies and even some private enterprises that have nothing to do with aerospace, such as goose factory, cat factory and other enterprise representatives also came to the stage to give an exchange report .

The former is mainly to share and exchange some technologies in the aerospace field, to promote business and popularity for their own companies, and so on.

The latter means that he has an idea and a budget to enter the aerospace field, or announces a satellite network plan or something.

Including Xu Chuan himself, at the request of Chief Qin Anguo, came to the stage to give a report on the development and direction of the aerospace field.

Of course, his speeches were not many, mainly focusing on the field of electromagnetic propulsion.

After all, since the last chat with Academician Yang Hong, the aerospace electromagnetic propulsion system is his preferred aerospace engine technology.

However, his fame lies here, and the direction he said has been recorded by many people in academia, industry, and even business.

All in all, industry and business can present themselves at the networking event, meet partners and much more.

More importantly, the investment in the aerospace field can be tax deducted one to two.

This is undoubtedly great news for those companies that pay large taxes.

Enterprises such as Goose Factory have their own demand and dependence on satellites. This time, the state has subsidized scientific research funds in the aerospace field in disguise, which will undoubtedly save them a lot of money.

The country has also promoted the development of the domestic aerospace field through this exchange meeting.

Of course, more importantly, through this kind of exchange meeting, the disclosure of Huaguo's goals and plans in the aerospace field will help draw the attention of Western countries led by the United States and drag them into the aerospace field.

In order to achieve the goal of slowing down the opponent's research progress in the field of controllable nuclear fusion, maintaining its own leading edge, expanding Huaguo's influence in the international community, and so on.

Today's meeting can be said to be a win-win situation for everyone present.

In this large-scale exchange meeting, apart from the daytime exchanges, there will also be an exchange party at night for the guests attending the meeting to get to know each other.

At the party, many people looked for that young figure in the venue with their eyes wide open, but to everyone's regret, that person did not come to the party.

At this moment, Xu Chuan has returned to Beihai Hotel.

For him, it doesn't make much sense to attend such a party. It's better to come back and study mathematics.

The research on the correlation effect and superconductivity in the multi-track strongly correlated system has not yet been completed, and he has to hurry up to get this done.

After all, superconducting materials with high critical magnetic fields are the basis for miniaturized and controllable nuclear fusion technology and aerospace electromagnetic propulsion systems.

In the hotel room, Xu Chuan, who ruled out a way again, put down the pen in his hand, raised his head and silently looked at the white ceiling.

Over the past few days, he has successively ruled out several different routes through mathematical methods, and has also tried several different methods to calculate.

But in the end did not get any good results.

However, if the research on the correlation effect and superconductivity in the multi-orbital strongly correlated system is really so easy to solve, it will not be a century-old problem in the physics world.

Taking a long breath, Xu Chuan looked down at the manuscript paper on the table, and began to think again.

"Most of the time, the strongly correlated system of electrons is basically described or described from the perspective of condensed matter, but quantum chemistry can also explain this, maybe you can try it from quantum theory?"

Staring at the manuscript paper on the table, Xu Chuan fell into deep thought.

"Strictly speaking, the single-electron (mean field) approximation does not mean that the interaction between electrons is ignored, but that the interaction between electrons is considered in the form of a mean field, that is, the two-body operator passes The trace with the single particle density matrix is ​​converted into a single operator."

"But the mean field approximation does not mean that there is no correlation. Because the wave function of Hartree-Fock is antisymmetric (Slater determinant), electrons with the same spin are actually correlated. This is called Fermi correlation."

"So, the mean-field approximation of the really missing correlation effect is the so-called Coulomb correlation."

"If you want to calculate this wide connection, you have to start with the specific form of the wave function. The approximate wave function used by the mean field to approximate Hartree-Fock is called the Slater determinant. incompatible."

Thinking about it, Xu Chuan involuntarily picked up the signature pen on the table again, and wrote on the manuscript paper:

[|Ψ\u003e=c0|Φ\u003e+∑i, aCai\u003e+∑ij, abCab/ij\u003e+···(eqn 1)]

Starting from the ground state configuration, the one-electron wave function |Φ|\\Phi\\rangle|\\Phi\\rangle is a good approximation of the many-body wave function |Ψ|\\Psi\\rangle|\\Psi\\rangle, indicating that the Coulomb correlation is very small .

In a weakly correlated system, the mean field approximation can qualitatively describe many properties of the system, but there are some quantitative deficiencies. These quantitative deficiencies are due to the contribution of those excited configurations that account for a small proportion.

In other words, it can be promoted!

Perhaps, starting from the field of quantum chemistry, it is really possible to find a mathematical path leading to the correlation effect in the multi-track strongly correlated system.

Staring at the data on the manuscript paper, Xu Chuan's eyes flickered with excitement.

He may have found a breakthrough.

It's just that how far this mouth can take him is still unknown.

PS: There is another one at night, ask for a monthly pass!