Chapter 71

On this day, a big event suddenly happened in the spaceship: academician Ding of the wolf design bureau made a voice and wanted to recruit a graduate student among the undergraduate graduates, which caused a sensation among the whole group of candidates!

academician Ding has always cultivated doctors, but this time he wanted to recruit a master's degree, so the opportunity is extremely rare.

Everyone knows clearly that contacting these top-level talents in advance will have a significant impact on his future academic career.

Because the number of applicants is too large, it is impossible to come here in an interview. The staff had to strengthen the hard and fast conditions for registration, so that the number of applicants was sharply reduced to less than 50.

Zhang Yuan opened the registration interface, saw his hard conditions and examination results, and was able to register. He was relieved.

At this time, Professor Wang Zhong sent a video.

“…… That old guy has been convinced by me. It's up to you. If there is a more suitable person than you, who has been competitive, no wonder others. Do you have any confidence in choosing one of the 50 experts? "

"Yes!"

"That's good. I'll wait for your good news!"

……

After a brief preparation, it's finally the day of the interview.

There are five interviewing teachers, two of whom are former colleagues of their own father. They are familiar with each other, and they all cast friendly eyes.

The one sitting in the middle is Professor Ding Zhaodong, and the one on the left is captain Ma Tao, who also looks at Zhang Yuan with a kind face.

"Don't be nervous, young man."

Captain Ma took a look at the materials on the table, and first asked, "you are Lao Zhang's son, as we all know, so I don't need to introduce myself. I have a question. What do you learn most from him? "

Nervous, with enough strength, he is not nervous at all.

Zhang Yuan said casually: "humble personal character, excellent study habits, free from foreign things, lofty goal and ideal!"

"Stop!"

Seeing that the professors around showed a slightly strange smile, Captain Ma asked again, "just tell me what his shortcomings are. What shortcomings can't you tolerate?"

Zhang Yuan was stunned. Is there any old gap between the captain and his father?

Or is it just a joke to ease the tension and seriousness?

It's possible.

Zhang Yuan thought for a while and said, "he is always demanding others with his intelligence. I find it hard for ordinary people to tolerate this. He thinks many things are very simple, so he orders others to do them casually. But he thinks that people have to do some simple things for half a day, and they may not even be able to do them So he always lost his temper for no reason

Everyone began to smile.

Zhang Yuan was a little confused about whether his answer was good or not.

Then comes the serious question time. Naturally, it won't be that kind of ordinary question.

One of the professors asked straightforwardly, "I once read your paper on robot kinematics. It's really a very good paper. But have you considered too much the problem of constraint computation for robots with few degrees of freedom? "

"In reality, many industrial robots don't need too many degrees of freedom, and the algorithms are also different What do you know about 2-rps-2-sps 4-DOF parallel robot? Just say an idea. It doesn't need to be lengthy. "

Zhang Yuan thought for a few seconds. In fact, this problem is relatively basic: "in terms of the complexity of the structure and the production cost of the parallel robot, the fully symmetrical parallel mechanism has great advantages The characteristic matrix of the four degree of freedom motion is 3T1R, 2T / / 2R, 2T ⊥ 2R, 1T3R, 3t2r, 2t3r, 3t3r

"Let's first discuss the mechanical generators in the form of simple open chains connected by these seven motions..."

Although he was asked not to make a long speech, he said it for more than ten minutes.

The professor squinted, nodded and said, "good answer."

It's not easy to think of so many things clearly in such a little time, which shows that Zhang Yuan has solid basic knowledge, quick thinking and brilliant mind.

“…… Do you have any research on the latest optical chips? Why not develop quantum chips with stronger computing power? "

After thinking for a few seconds, Zhang Yuan replied: "I'm sorry Photonic chip is a computing framework based on photonic circuit, which is equivalent to the use of numerous micro optical switches on the chip. Its function is similar to the logic gate in semiconductor chip Photonic chips use the combination of different wavelengths, phases and intensities of light to process information in an array composed of complex mirrors, filters and prisms

“…… Like microelectronics, they are all semiconductor architectures based on silicon materials, so they are equivalent to the extension of traditional chips. Its computing power is more than 10000 times that of ordinary silicon-based chips, and with the current technology, there is still room for further development. "

"Although the computing power of quantum computer can reach 100 million times or even 1 trillion times of that of silicon-based chip, it must realize the relevant number of quantum entangled states. 40-50 entangled states is the limit of current technology, and it is very difficult to improve. But the computing power of this number of entangled states is not as good as that of traditional silicon-based chips.... ""Therefore, although quantum chip is good, it is difficult to make further progress without a major theoretical breakthrough, so it is not the mainstream of current research."

"Very good, very right." The professor nodded slightly. This time not only examined the theoretical basis, but also examined the breadth of knowledge.

Many professors raised many questions, and Zhang Yuan dealt with them one by one with ease.

"I have a question, too." Ding Zhaodong suddenly opens his mouth.

"Excuse me."

Academician Ding Zhaodong said slowly, "what do you think of the industrialized production of the new civilization? What do you think is the biggest constraint on the development of new civilization? "

Is it such a big problem?

Zhang Yuan cleared his throat and replied, "we do have some good industrial bases. For example, the spaceship carries the most advanced lithography machines, some nano material production rooms, and some industrial master machines. We can produce some parts, but many upstream industrial chains are completely disjointed. "

"For example, chloroform, caprolactam and acrylic acid, which are the most basic chemical raw materials, have only a small amount of inventory, and can not be produced when they are used up. If we use biosynthesis, the cost is too high. "

"If we can successfully reach the target planet and obtain a lot of material resources, we have to start with the development of the most basic raw materials. In my opinion, the biggest factor restricting the development of civilization is actually Population. The population is too small to make the whole industrial system work. "

"I once read a report that the minimum population of the earth's industry is 1.6 billion. Although the quality of our population is high enough, the number is only 500000, which is far from enough. "

"It's reasonable. In fact, it's also something we're worried about..." Before academician Ding answered, a professor nodded first.