Jiang Shuiyuan also hurriedly sat up straight when he heard the sound, and at the same time looked towards the door, and saw a young man walking into the classroom in a graceful manner.

Yes, "personable". Prior to this, Jiang Shuiyuan had always thought that the teachers of Jingshi University were either arrogant and unruly like Uncle Ge, or as gentle and elegant as Hui Chengze, and he never thought that there would be people who would be so personable. I saw that his facial features were white, he was wearing a pair of gold-wire glasses, and his hair was combed neatly. The crisp cashmere coat accentuates the slender figure, and the dark grey Scottish scarf drapes casually around the neck. The navy blue trousers are straight, and the leather shoes on the feet are also recognizable. The whole person looks delicate and chic, and it reflects the smart fashion in the quiet. If he hadn't appeared in the classroom, Jiang Shuiyuan would have thought he was a fashion model.

He stood still on the podium, looked around, and then introduced himself with a smile: "Hello everyone, my name is Han Tingsong, and I am a lecturer in our mathematics department. According to the arrangement of the department, I will teach you the course "Numerical Methods for Partial Differential Equations" this semester. -- Actually, it can't be called a lecture, because my understanding of partial differential equations is also very limited, so let's all learn and make progress together! If there is a mistake, you are welcome to point it out directly. ”

It's quiet offstage.

Han Tingsong didn't talk nonsense anymore and began to cut straight to the topic: "Before that, everyone should have been more or less exposed to partial differential equations, and know that partial differential equations are an important branch of mathematics, which has a wide range of connections with other branches of mathematics, and has a wide range of applications in natural sciences and engineering technology, such as physics, geology, numerical weather prediction, stress analysis of large dams, nuclear tests, aircraft design, and even war decision-making. In fact, as a branch of mathematics, partial differential equations appeared in the 18th century, and the first three basic mathematical and physical equations that were systematically studied were the wave equation, the heat conduction equation, and the harmonic equation, and the main tool used was classical analysis. In the next two centuries of research and exploration, many important achievements have been made in the theory and application of partial differential equations, and a variety of methods for solving problems have been established......"

Han Tingsong didn't take the textbook, he pinched a piece of chalk and talked there, but he was concise and not annoying, and sorted out the important basic concepts of partial differential equations in just one class, and introduced the Fourier transform and complex matrix, which benefited the river source a lot.

During the recess, Wang Canlong took out a plastic water cup and poured a few sips of "Gu Dong" and "Gu Dong", and then asked Jiang Shuiyuan: "Dude, do you understand?"

Jiang Shuiyuan smiled: "It's okay, after all, it's all an introductory historical introduction and knowledge preparation, it's not too difficult, I guess I won't understand it if it's difficult." ”

Wang Canlong seemed to be very satisfied with Jiang Shuiyuan's answer, and said in a teachable tone: "Knowing is knowing, not knowing is not knowing, and knowing is knowing! Don't look at Teacher Han's slow and shallow speech now, that's because the course has just begun, and you have to give everyone a process of getting started and adapting, and you will find that he is going to drive fast later, and the content he talks about is not limited to teaching materials." The teachers at Jingshi University are like this, they take one class enough to take three or four classes at other colleges. So you must take good notes during class, and you must review and preview carefully when you go back, otherwise you won't understand at all after three or four classes!"

Jiang Shuiyuan looked humbly taught: "Thank you for your advice!"

"Pointing is not counting, it's just a little experience. ”

Jiang Shuiyuan was a little curious: "Listening to the tone of the eldest brother, it shouldn't be a short time to audit at Jingshi University, right? Why do you need to take such a basic course?"

The corners of Wang Canlong's mouth twitched slightly, and it took a long time to answer: "First of all, the course "Numerical Methods of Partial Differential Equations" is not basic, in fact, the mathematics departments of many local colleges and universities do not even offer courses on partial differential equations. Secondly, after all, Mr. Han is a Ph.D. from Princeton, and he is exposed to the forefront of the subject, and the content he teaches is not limited to textbooks, and many new ideas and ideas will open people's eyes, which is also the characteristic of Jingshi University that is different from other schools. Also, do you think so many auditors are here to be auditors?"

"Or else?"

Wang Canlong said to Nunu in the direction of the podium: "Look for yourself!"

Jiang Shuiyuan found that many people were gathered around Han Tingsong, some of them were close, some asked questions, some submitted their papers or books to him for guidance, and some even sent local products directly, which surrounded Han Tingsong. Jiang Shuiyuan was also dumbfounded when he saw such a Western scene: "Who are they?"

"A lot of people are just a means, and selling themselves is the goal. Wang Canlong's demeanor is very complicated, with disdain and envy, and envy with a little disdain, just like seeing the little sister next door to make money and buy a luxury car and mansion. He couldn't help but raise the plastic water cup and pour a few sips of "goo dong" and "goo dong" and pour a few sips of cool white water: "Do you understand how to sell yourself?" Some people want to go to graduate school, some people want to win awards, some people want to publish papers, some people want to evaluate professional titles, some people want to win project funding, and some people want to come to Jingshi University to gild...... In short, there are all kinds of reasons, and every Jingshi University teacher is a scarce resource that is worth working hard for. Therefore, universities are not ivory towers, and academia is also rivers and lakes!"

Jiang Shuiyuan was not as cynical as Wang Canlong, and only sighed: "No wonder everyone says that the university is a small society." ”

"What do you mean by 'the university is a small society'? The university is a society! I don't believe you wait for the students to evaluate the scholarships, the teachers to evaluate the awards, and the professional titles. Wang Canlong said indignantly, "That is, Jingshi University is a little more detached, so when I prove the four-color problem, I will come to Jingshi University to be a teacher!"

Jiang Shuiyuan once again sent his blessings: "May your dreams come true as soon as possible!"

As Wang Canlong expected, in the next class, Han Tingsong began to drag racing frantically, not only explaining the basic concept of the finite difference method at the speed of the wind sweeping the leaves, but also interspersed with the development and application of the finite difference method. At the end of class, he listed a large number of reference books, such as "Introduction to Modern Partial Differential Equations", "Methods for Difference of Partial Differential Equations", "Numerical Solutions of Partial Differential Equations", "Boundary Value Problems of Partial Differential Equations", etc., and then he patted the chalk ash on his hand in a dashing manner: "These books are available in the library, you can go through them when you have time." As for the homework, I won't assign it, anyway, there are exercises at the end of each chapter of the textbook, you can do it yourself, anyway, it's very simple, and it won't delay your and my precious time. Class!"

As soon as I finished class, another group of people surrounded me.

Wang Canlong looked at Jiang Shuiyuan with a smile: "Dude, do you understand this time?"

Jiang Shuiyuan didn't know how others felt after class, anyway, he was dizzy and his eyes were straight, and he smiled bitterly when he heard the words: "I don't know if I understand it, I feel that my brain is a little insufficient." ”