Research starts with PhD students

Chapter 15 He is indeed a handsome man!

The flight from Capital Airport arrived at Sudong Airport at 11pm.

It was already early morning when Zhang Shuo and Luo Yongjun walked out of the airport and took a taxi to the vicinity of Soochow University.

Zhang Shuo declined Luo Yongjun's invitation and found a hotel near the school. He took a shower, lay on the bed, closed his eyes and fell asleep. When he woke up, it was already morning.

He hurriedly packed his things and returned to school.

When I arrived at the school, I found the dormitory building according to my memory. It was the last building of graduate dormitory. I went up to the third floor and found Room 302 accurately.

Zhang Shuo pushed open the door.

"Who is it? Why don't you knock on the door?"

An impatient shout came from the bathroom. A short, sturdy man was brushing his teeth and peeking out through the bathroom door.

It was Zhang Shuo’s roommate Huang Kai.

Huang Kai came out when he saw Zhang Shuo and asked in confusion, "I saw Liu Chengjie yesterday, why didn't you come back together?"

"I came back too late yesterday, the school was closed, and I stayed in a hotel."

Zhang Shuo put his backpack on the chair and said, "Teacher Luo and I have something to do, so I asked Liu Chengjie to come back first."

Huang Kai nodded without further investigation.

He went back to the bathroom to continue washing himself, and came out after a while, staring at Zhang Shuo with some surprise.

"what happened?"

Zhang Shuo touched his cheek with his hand.

"It's different."

Huang Kai continued to stare at Zhang Shuo and said seriously, "You are really different now. I remember when you went there, you didn't even have a smile on your face. Now you look much more relaxed. Have you figured it out?"

"There's nothing you can do about this kind of thing if you can't figure it out." Zhang Shuo pursed his lips and shrugged.

"Just figure it out!"

Huang Kai pulled a chair and sat down. "I advised you to be more open-minded before. Anyway, the school will let you continue studying. As long as you get a doctorate, it doesn't matter whether you have a master's degree or not."

"The scholarship doesn't matter. Otherwise, you can learn from me and do part-time work. It's still very profitable. An hour is more than 100 yuan. When the time comes, I will introduce clients to you."

"Thanks in advance."

Zhang Shuo smiled and replied, then he looked at the time and stood up immediately, "Let's go quickly, or we'll be late."

"Yes, class!"

"The first period is Li Weihua's class!"

Huang Kai reacted, took his things and walked out.

They hurried to the teaching building.

When I arrived at the classroom, there were already more than a dozen people inside, all sitting in the front row or in the middle.

Zhang Shuo found a seat at the side and sat down.

Liu Chengjie came over quickly and asked quietly about the project, "How was the negotiation going? Did you get the project?"

Zhang Shuo nodded gently, "It's settled."

When Liu Chengjie wanted to ask something else, a middle-aged man in his 40s walked into the classroom, and he hurried back to his seat.

The person who came was Li Weihua.

Li Weihua is also a doctoral supervisor, and his course is called "Second-Order Elliptic and Parabolic Partial Differential Equations."

In the application field of partial differential equations, second-order elliptic partial differential equations and parabolic partial differential equations are both major categories.

The motion characteristics of physical systems, fluid dynamics in fluid mechanics, electromagnetic fields in electromagnetism, sound fields in dielectric mechanics, etc. all require relevant types of partial differential equations to describe.

Many doctoral students studying partial differential equations also choose second-order elliptic and parabolic partial differential equations as their research direction.

There are many applications, many research points, and many references.

This is a direction that is easy to write papers and produce results.

Li Weihua has very high requirements for his students. He does not allow students to be late, and he explains the courses very seriously.

This lesson talks about second-order elliptic partial differential equations used in the description of electromagnetic fields.

The explanation includes the characteristics of the equation and the solution method. There are many solutions to the second-order elliptic partial differential equation, the most important of which is to use the Fourier series method to solve it.

The Fourier series method is a method that uses series to solve elliptic partial differential equations. It can transform elliptic partial differential equations into a series of Fourier series to obtain the solutions of elliptic partial differential equations.

Li Weihua gave students an example of the process of solving an equation.

Just solving one equation took more than half a class period, and with the other overview explanations, the time was almost up.

Zhang Shuo listened and thought.

The content taught in class was not difficult. It was just solving conventional second-order elliptic partial differential equations, and the method used was the very popular Fourier transform method.

What he noticed was the complexity of the solution. It was just a regular second-order elliptic partial differential equation, but it was a special case equation that could be solved exactly, but the analytical process was so complicated.

This type of equation has many applications in experiments.

In the data calculation work of microscopic physics experiments, it is impossible to slowly find the exact solution in this way. Instead, we directly use the numerical substitution method to find the range of the solution of the equation, that is, to circle a range and make sure that the exact solution is within the range.

“Can we use a universal method to calculate the boundary value range of the exact solution?”

This is the question Zhang Shuo was thinking about.

The course is over.

For Zhang Shuo, the course was not difficult, but for other doctoral students, it was still difficult to fully understand it.

For example, Huang Kai.

He went to Li Weihua to ask about content he didn't understand in the course, and other doctoral students were standing by and listening.

Zhang Shuo walked over and stood by, waiting patiently.

After others had asked questions, he stepped forward and asked, "Teacher Li, for the type of equations you talked about, is there a general method that can calculate the fuzzy boundary values ​​using various numerical values ​​of the equations?"

Li Weihua was stunned when he heard it. He took a long time to understand it carefully before asking, "Do you want to use computer methods to directly calculate the range of the exact solution?"

Zhang Shuo nodded, "I am thinking about this question."

Li Weihua thought about it carefully and said, "If we only find the boundary of a certain type of equation by manual calculation, this is a numerical solution."

"You said that you use various numerical values ​​of the equation to calculate the fuzzy boundary. Doesn't this involve fuzzy mathematics?"

He thought and shook his head. “It’s too difficult to find a general method, even for just one type of equation.”

"If you are doing research in this direction, I still suggest you give up. This is not something a doctoral student should accomplish..."

He said as he packed up his textbooks, then asked, "By the way, what's your name?"

"Zhang Shuo."

"Zhang Shuo?"

Li Weihua was stunned.

There is no one in the School of Mathematical Sciences who doesn't know the name of Zhang Shuo. Naturally, he also knows Zhang Shuo, but the new semester has just begun, and he has only now matched him with the real person.

Just as he was about to say something, he saw several people walking into the classroom.

The leader was a female comrade in her 50s, Wang Duoju, the administrative director of the college.

"Director Wang?"

Li Weihua took the initiative to walk over and asked in surprise, "Are you...looking for me?" There was some joy in his tone.

Wang Duoju is the administrative director of the college, responsible for personnel, office and other work. More importantly, she is in charge of project work in the direction of school-enterprise cooperation.

She came to me on her own initiative, asking me to join a school-enterprise cooperation project?
As Li Weihua was thinking this, Wang Duoju nodded at him and called him "Professor Li" symbolically. Then she looked at Zhang Shuo with a smile on her face and said, "You are Zhang Shuo, right?"

"You are……"

"You can call me Director Wang." Wang Duoju walked closer and looked at Zhang Shuo enthusiastically, "He is indeed a handsome man!"

"I came to talk to you about the project."

"The college has already signed an agreement on your cooperation project with the Institute of High Energy Physics. I specifically asked about it and I think the payment will be made within a week."

"You have a personal grant of 100 million, right?"

She took out her phone and said, "You can add me as a friend and send me your bank account information. Then the finance department will transfer the money directly."

"it is good."

Zhang Shuo took out his phone and added a friend.

“That’s convenient.”

Wang Duoju smiled and said, "Actually, you can ask other people to come. I came here specifically to see you. Talents like you are rare."

"If you have any questions about the project in the future, you can come to me."

"I have told the finance department that any reimbursement needs for this project will be approved as long as they do not exceed the designated scope."

“The college gives absolute support!”

Wang Duoju spoke a few more words to Zhang Shuo and then left.

Li Weihua felt a bit surreal watching from the side. The administrative director of the college came to talk to a doctoral student about a project? A doctoral student could get a million-dollar personal grant?

He took the things, walked over and said, "Zhang Shuo, the research idea you mentioned is very good."

"Although the research is very difficult, that is for ordinary doctoral students. It won't be a big problem for you."

"I'll look for some information when I get back and give it to you in the next class. It might be helpful to you. If you have any questions, you can always come to me..."

(End of this chapter)