As soon as the New Year passes, even in the city, the flavor of the New Year gradually becomes stronger.

NTU, the campus is deserted, and ordinary college students have already left the school during the winter vacation.

In the office, Xu Chuan is also giving the last small class of the year to several students he has brought with him.

Unlike undergraduates, graduate students, whether master's or doctorate, do have winter and summer vacations, but the duration of winter and summer vacations generally depends on the conscience of the mentor and the projects in hand.

If you don't have a project in hand when the winter and summer vacations are approaching and the tutor is good, the winter and summer vacations will be longer, and it is not impossible to follow the undergraduate students or even take some holidays earlier.

If the project in hand is busy, or the 'exploitation' of the supervisor is more serious, it can be said that the winter and summer vacations of graduate students are almost a few days.

Of course, Xu Chuan is naturally not an unscrupulous mentor, and the few students who studied with him have not left for vacation so far, and they are voluntary.

Because when the year is approaching, the probability of their tutors appearing on the campus of NTU is much greater than usual.

Especially when the projects of Xinghai Research Institute and Chuanhai Materials Research Institute are suspended or slowly advanced due to the end of the year, Xu Chuan will also take the initiative to give them some targeted lessons.

These are rare opportunities that don't usually exist.

And this rare opportunity, whether it is Ding Rui, who is studying for a doctorate, or Rong Xinji, who is studying for a master's degree, no one will let it go.

In addition, there are three senior brothers and sisters in front, Amelia, Gu Bing, and Cai Peng, all of whom graduated with extremely excellent grades, and the psychological pressure of several people is undoubtedly great.

Taking advantage of all opportunities and working hard to acquire knowledge is the only thing they can do.

In general, the exact solutions of these partial differential equations cannot be given explicitly, such as the finite difference method, the finite element method, the spectral method, etc. However, the order of precision of the numeric format is for the global error. ”

"However, in the precision order of numerical value format, there is a class of problems that are relatively easy to study from the exact solution of partial differential equations.

In the office, when he was idle, Xu Chuan gathered several students together and gave them a small class to give them a simple explanation of the knowledge in the field of partial differential equations.

However, for him, it was obvious that these simple knowledge were not so easy to understand in the eyes of several students.

In the office sitting in rows, aside from Gu Bing, who had graduated, several other students listened more or less with frowns and small faces.

Hearing Xu Chuan's question, Rong Xinji, who specializes in differential equations and partial differential equations, quickly raised his hand and replied: "The question of time dependence. ”

Xu Chuan nodded with a smile and said, "That's right, for the problem of time dependence, starting from the accurate solution of the partial differential equation, the ratio of the numerical error to the time step introduced by only one step of the numerical format is the local truncation error." ”

So, in what sense does the "high precision" format maintain high accuracy when the partial differential equation is nonlinear and the solution is interrupted? Has anyone thought about this? ”

Hearing this, everyone frowned this time, including Gu Bing, who had already graduated and was listening to the lecture on the side, all fell into thought.

Looking at the few students who were silent in the office, Xu Chuan smiled and was about to speak, when there was a sudden knock on the door of the office.

A pretty figure walked in with some bouncing steps, carrying a cake in her hand.

"Dude! Happy birthday! ”

A crisp and pleasant sound like a yellow oriole sounded in his ears, and Xu Chuan turned his head in some surprise: "Why are you back?" ”

"Of course, I'm back for your birthday." Xu Xiao smiled and raised the cake in his hand.

Xu Chuan glanced at her and said with a smile: "Don't come to this set, every time you celebrate me, you don't hold back your fart, what bad idea did you play this time?" ”

said so, but he was still very moved by Xu Xiao rushing back from England to celebrate his birthday. Although part of the reason for this is that this girl took advantage of this time to take a vacation and come back for the New Year.

After all, his birthday is the day after the New Year, and the New Year is not a few days away.

Although there is no custom of the New Year in Europe, and there will be no holiday at this time, it is really not difficult for Xu Xiao to take a leave to come back for the New Year.

After all, she still has a Nobel Prize brother on her head, and I'm afraid that no professor will risk offending him to prevent Xu Xiao from going home for the New Year.

Standing opposite, Xu Xiao, who was wearing a beige down jacket, pouted, and said dissatisfiedly: "How can anyone talk about his sister like this, I will come back thousands of miles to celebrate your birthday, if you are not moved, forget it, and say bad things about me!" ”

Xu Chuan glanced at her and said, "On my birthday in 2019, you cheated five million from me, and on my birthday in 2020, you cheated another 10 million, and in 2021, you cheated 20 million more and more every year, nominally to celebrate my birthday, but in reality?" ”

Hearing this detailed number, Xu Xiao smiled: "Isn't this all for research, brother." Besides, I didn't waste this money, and there were still results. ”

Xu Chuan said with a smile: "For the results you have made, I will find a biological research team outside, and I can make it with only one-fifth of the funding, do you believe it or not?" ”

This girl, with his support behind her, is also a lavish style when she spends money.

However, he has always supported the expenditure on scientific research, and if he did not support it, Xu Xiao would not be able to fool him into funding again and again.

Besides, money is a number to him, life does not bring death, he only has this one sister, who can he spend if he doesn't give her flowers?

Xu Xiao pouted and said, "It's not normal to spend some money on research, and experience is priceless!" ”

Xu Chuan glanced at her and said, "Say, how much are you going to cheat this year?"

Hearing this, Xu Xiao immediately changed his face, raised his finger energetically and promised, "I won't ask you for money this time!" ”

Hearing this, Xu Chuan suddenly looked vigilant: "Don't want money, then what do you want?" ”

From the small pit to the big one by this girl, he is about to get out of the psychological shadow.

Looking at his own brother with a vigilant look, Xu Xiao was about to cry, pouting and shouting aggrievedly: "Brother! What about trust between people! I'm your dearest sister! Can't I just give you a birthday? ”

Xu Chuan smiled disdainfully: "If you give me a birthday, just three words, you have to add money!" Each time more than ever, your trust in me has long since disappeared infinitesimally. ”

In the office, hearing this, one didn't hold back, and several students who sat in a row to eat melons laughed out loud.

I didn't expect them to hear the phrase 'gotta more money' come out of the professor's mouth one day.

Xu Chuan didn't care too much, these students have been with him for almost two years, except for Liu Jiaying, who was newly recruited recently, they basically know Xu Xiao.

Ignoring Xu Xiao's girl, he looked at the few students sitting in the office, knocked on the table and said.

"As for the question I just asked about the meaning of the "high precision" format when the partial differential equation is nonlinear and the solution is interrupted, it is left to the question of the mind of the New Year's event. ”

"When you come back in the next year, hand in the answers to each of your thoughts on this question and let me see."

Hearing this, the office suddenly wailed.

Do they know that the professor's 'hilarity' is so easy to watch?

It's good now, the already handful of winter vacation time has to be taken into it, is it really easy for them!

Damn it!

After pouring a cup of hot water for this sister who rushed back from thousands of miles away, Xu Chuan asked with a smile: "Have you bought a ticket to go back to your hometown?" ”

Xu Xiao warmed his hands with a glass of water: "No, brother, the New Year is over, and I can't grab a ticket, you can help me buy it." ”

Xu Chuan smiled dumbly and said, "Feelings, do you still want to rub the car back when you come to my side?" ”

Xu Xiao said with a smile: "I'm not here to celebrate your birthday for my brother, how can it be called a scholar's business, by the way, do you understand by the way?" ”

Xu Chuan gave her a blank look, didn't say anything, and sent a message to Zheng Hai, asking him to help buy an extra ticket.

What he didn't know, of course, was that this message was actually redundant.

At his current level, whether he is traveling by high-speed rail or plane, basically the corresponding carriage or business class will be locked in advance, that is, the entire carriage or business class will only be provided to him alone.

So even if you bring one more Xu Xiao, you don't need to buy more tickets.

"Brother, are you a new student?"

In the office, Xu Xiao took a probing glance at the student room outside, and his eyes fell on Liu Jiaying, who he had never seen before.

Although she hadn't seen it, she always felt a little familiar.

Xu Chuan nodded and said, "You should know, Liu Jiaxin's sister, Liu Jiaying, used to go to school in Fudan, and only turned around to follow me two months ago." ”

Hearing this, Xu Xiao's eyes widened suddenly, his mouth widened, and he looked at Xu Chuan in surprise and surprise, and said in a daze: "Sister flower? Dude, you're playing too."

Xu Chuan interrupted her with a black face: "What are you talking about, what the hell have you learned when you went abroad to study?" ”

Xu Xiao stuck out his tongue and closed his mouth with an embarrassed face.

On the way back, she just read Ben, and she couldn't help but think of it.

Ahem, you can't continue to say this, it's 404 if you continue.

In the office, after the two brothers and sisters chatted for a while, Xu Xiao ran out to find Liu Jiaying outside to play, Xu Chuan didn't care, sorted out the documents in the office, and prepared to go back to his hometown for the New Year.

After flipping through the information, he sorted out the papers and materials related to quantum chemistry and uploaded them to the network disk, ready to take a look at them during the Chinese New Year.

Compared to previous years, this year he has a lot less things on his hands.

Those large-scale projects, whether it is aerospace or the strong particle collider, are currently progressing smoothly and do not need too much concern from him.

As for the rest, basically the management of the laboratory and the institute can handle it.

Therefore, Xu Chuan plans to take advantage of the Chinese New Year to brush up on quantum chemistry-related materials and papers.

He has established the interface theory of the microscopic solid reaction process of electrochemistry, but it is still an extremely difficult and huge task to extend it to the four major fields of traditional chemistry.

After a simple dinner in the villa with a few students and Liu Jiaxin, who came from the Internet, and held a small birthday party, the 23-year schedule has also entered the countdown time.

Returning to his hometown from Jinling, on the high-speed train, Xu Chuan flipped through the papers in his hands.

On the side, Xu Xiao was holding a mobile phone and didn't know what he was swiping.

Suddenly, she raised her head and looked over, and asked curiously, "Brother, speaking of which, when are you going to get married?" ”

Hearing this question, Xu Chuan was stunned for a moment and looked at Xu Xiao: "Why did you suddenly ask this?" ”

In the business class, Zheng Hai and Tang Sijia in the back row also pricked up their ears.

This person's marriage is a real big deal.

Xu Xiao thought for a while and said, "After yesterday, brother, you have already reached twenty-six into twenty-seven, at this age, the little brothers of the same age as you in the village are all married, and you are the only one left." ”

Xu Chuan smiled: "What, do I have to get married when they are all married?" ”

Xu Xiao shrugged his shoulders and said, "Not really, but you told your mother before you would consider getting married at the age of thirty, but when you reach the age of thirty, Sister Jiaxin will be thirty-one." ”

Xu Chuan paused and looked at Xu Xiao blankly.

"What's wrong? Dude? Xu Xiao asked curiously.

Coming back to his senses, Xu Chuan shook his head and said softly, "It's nothing." ”

In the business class, the atmosphere was suddenly silent for a while.

Xu Chuan didn't know what he was thinking about holding the paper in his hand, and Xu Xiao on the side didn't speak again.

The high-speed rail roars across the vast land, and during the Spring Festival season, there are wanderers returning home everywhere.

Looking at the travelers outside the window, Xu Chuan, who didn't know what he was thinking, came back to his senses, looked at Xu Xiao, and asked, "By the way, what is the mathematical work you talked about yesterday?" ”

Yesterday's birthday, Xu Xiao celebrated him, and he didn't ask for money, but he asked him to help make a mathematical model.

It's just that because of the dinner party in the evening, he didn't have time to ask, this will happen to be on the high-speed rail, he can take a look.

Hearing Xu Chuan's inquiry, Xu Xiao hurriedly turned on his computer.

"I've sent you an email, brother, you can take a look first."

Xu Chuan nodded, took the notebook from the small table on the side, slid his fingers twice on the touchpad, and clicked on the mailbox.

In the mailbox that he paid special attention to, a newly arrived email was beating, he clicked on the email, and looked at the title of the email, but when the title came into view, the whole person was slightly stunned.

【Research Theory of Simulated Neural Signals and Electrical Signal Conversion Based on Quantum Theory】