Liu Tingbo's movements were very fast, and early the next morning, he called and said that he had helped Pang Xuelin contact a big man from the School of Materials Science and Engineering.

"Xiao Pang, I will introduce to you our Jiangda State Key Laboratory of Silicon Materials, Director of the Institute of Semiconductor Materials Academician Xu Xingguo, Academician Xu has been engaged in the research of semiconductor silicon materials for a long time, the research areas include silicon materials for VLSI integrated circuits, solar photovoltaic silicon materials, silicon-based optoelectronic materials and nano-silicon semiconductor materials, etc., he heard that you are interested in materials science, let me take you to see, as long as you complete the undergraduate professional courses, you can directly apply for his graduate school."

Listening to the voice on the other end of the phone, Pang Xuelin couldn't cry or laugh, Academician Xu is an expert in the field of silicon materials, if he really applied for his graduate school, then in the future, he will use carbon nanotubes to make carbon-based CMOS, which will smash his mentor's job!

Although he thought so in his heart, Pang Xuelin still agreed.

He is mainly good at the preparation of high-purity carbon nanotubes and two-dimensional graphene materials, if he can really convince this big man to change careers, he may not be able to develop real carbon-based chips in the future.

"Okay, Dean Liu, have you made an appointment with Academician Xu, when will I go to him?"

"This afternoon, he happens to be free in the afternoon, let's go to the lab to find him!"

"Okay, that's it!"

……

At two o'clock in the afternoon, Pang Xuelin, under the leadership of Liu Tingbo, met Academician Xu Xingguo at the State Key Laboratory of Silicon Materials on the Yuquan Campus of Jiangda University.

Academician Xu is in his fifties, with a Chinese face, thick eyebrows and big eyes, it can be seen that he should be a handsome guy when he is young, even at this age, his body shape is not out of shape at all, and he is full of energy.

"Professor Xiao Pang, I've admired my name for a long time, and I've wanted to meet you for a long time, but I've been here on the Yuquan campus most of the time, so I haven't been able to see you, and today I finally saw the real person!"

Xu Xingguo got up and smiled.

Although Pang Xuelin is young, his academic status is even above Xu Xinguo, who is an academician of the Chinese Academy of Sciences.

After all, in China, academicians are hundreds of years older, but the big man level of the Fei Award is just Pang Xuelin.

Therefore, for Pang Xuelin, even if the other party has something to ask for him, Xu Xingguo did not slack off at all.

"Hello, Professor Xu!" Pang Xuelin smiled and shook hands with Xu Xingguo and said, "Dean Liu should have told you, I want to learn some more material science, I don't know if it's inconvenient for you." ”

Xu Xingguo said with a smile: "Convenient, there is no problem on my side, but if you want to be admitted to my graduate school, you must at least have an undergraduate professional knowledge level, I heard Lao Liu say that you have completed the self-study of the undergraduate professional course of materials science?" ”

Pang Xuelin nodded and smiled: "Yes!" ”

Pang Xuelin said this very low, in fact, in the years of wandering the earth world, he did not relax his learning, especially the basic knowledge of materials science and chemistry, he learned it all over again, and even according to his level in the field of carbon nanotubes and graphene alone, I am afraid that there is no one who surpasses him in this world.

Xu Xingguo said with a smile: "That's it, I have a set of papers here, if you can do more than eighty points, then I will directly ask the School of Materials to organize a special professional course exam for you, if you can still pass, then you will write a graduation thesis, and the school will directly award you a bachelor's degree in engineering." What do you think of coming directly to me for graduate school next year? ”

Pang Xuelin said: "No problem! ”

"Okay, then let's not talk nonsense, you make this test paper first!"

Xu Xingguo had obviously prepared before, and handed a scroll that still exuded the fragrance of ink to Pang Xuelin.

Pang Xuelin took the paper, found a place in the office directly, and picked up the pen to answer.

Xu Xingguo and Liu Tingbo on the side did not speak, and watched Pang Xuelin answer the question with interest.

Although this paper was made by Xu Xingguo temporarily, there are more than a dozen big questions, but the question type involves all aspects of the field of materials science, and the difficulty is comparable to the postgraduate examination questions of the materials major, which can be regarded as a comprehensive assessment of Pang Xuelin's professional knowledge.

For example, the first question is about the field of materials physics.

[Describe the band structure characteristics of conductors, semiconductors, and insulators.] 】

Pang Xuelin glanced at it and wrote the answer directly in the blank.

For Pang Xuelin, the answer to this basic question type has already been imprinted in his mind, and he almost doesn't need to think about it.

[The conductor contains an under-band, and under the action of the external field, the electron distribution on the under-band is shifted, thus changing the original central stacking state, and the motion current formed by the electrons occupying different states cannot be completely offset, and the current formed by the unoffset part is the macroscopic current. Insulators do not contain incomplete bands, and the electrons in the full state will not be affected by the external field to produce a distribution that deviates from the equilibrium state, while some insulators containing empty bands ......】

In the second question, let Pang Xuelin explain the quantum size effect.

[Quantum size effect: when the particle size drops to a certain value, the electron energy level near the metal Fermi level changes from quasi-continuous to discrete energy level, and semiconductor particles have discontinuous highest occupied molecular orbital and lowest unoccupied molecular orbital, and the energy gap becomes wider, which in turn leads to photoelectric and superconducting properties different from macroscopic objects, such as: the transition from conductor to insulator, the blue shift phenomenon of spectral absorption, and the magnitude of the magnetic moment is related to the odd and even number of electrons......]

In the third question, in the preparation of one-dimensional nanomaterials, the vapor-liquid-solid growth mechanism is used, and let Pang Xuelin briefly describe the basic principle of this growth mechanism.

Pang Xuelin also won it easily.

Next, the fourth question......

Question 5......

……

It only took less than half an hour for Pang Xuelin to complete all the answers to the test paper issued by Xu Xingguo.

"Professor Xu, I've answered all these questions, take a look!"

Xu Xingguo took the scroll and went through it from top to bottom, and couldn't help but be a little surprised.

Although these test questions are not difficult, they involve a lot of knowledge points, and they involve a wide range of topics, from materials chemistry, materials physics, material mechanics to new functional inorganic non-metallic materials, nanomaterials, artificial bandgap materials, etc., Pang Xuelin not only completely answered these questions within half an hour, and there are no errors or omissions in the middle, which is rare.

Even some of his graduate students don't necessarily do that.

This shows that Pang Xuelin has a very solid professional basic knowledge in the field of materials science.

Liu Tingbo on the side was a little curious: "Old Xu, how is Professor Xiao Pang's answer?" ”

Xu Xingguo smiled: "It's better than I imagined, Professor Xiaopang, if I hadn't seen it with my own eyes, I really couldn't believe that you could get a full score on this test paper, even some of my graduate students may not be able to do it!" ”