Go back to the past and be a schoolboy

Chapter 243 Mathematics should face the national economy

"The universe is so big, the particles are so small, the rockets are so fast, the chemical engineering is ingenious, the earth is changing, the living things are so dense, and the daily use is so complicated. Mathematics is everywhere."

Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Swish Is there any comrade willing to take the initiative to stand up and read the above sentence aloud?"

The masters under the podium looked at me and I looked at you, their eyes were full of doubts, and they really didn't know what the new teacher wanted to express inside and outside the words.

Fortunately, Cheng Nuo had expected all of this. He came down from the podium and walked to the center of the classroom and said, "A gentleman avoids the three points, that is, avoids the pen of the scribe, avoids the edge of the warrior, and avoids the tongue of the debater. I can understand everyone's performance." I understand, let me introduce myself first, my name is Cheng Nuo, I am a new consultant hired by our Jiangnan Shipbuilding Institute, and I am also the main lecturer of this class, and we will work together for a long time in the future."

After a pause, Cheng Nuo turned around and pointed to the line on the blackboard and said seriously: "How about this, whoever stands up first, I will add 10 points to his normal score. As for what this normal score is for, it is very easy Simple.

It is an important part of the total score of comrades in this class. The more points you usually get, the higher the total score and the better the evaluation of the individual. "

As soon as the words fell, Li Nanteng stood up from the bench.

"Teacher, let me come..."

But he ignored it, he only sat on one end of the bench, and there were other comrades sitting on the other end.

Standing up suddenly caused the center of gravity of the bench to be unstable, and it fell over in an instant, and the companion was immediately thrown on his back.

"Oh, what the fuck..."

"Sorry, I ignored you just now, are you okay?"

Seeing that the situation was not going well, Li Nan reacted instantly and wanted to help his companion, but Cheng Nuo took the lead, and joked while helping him: "It seems that Comrade Li Nan values ​​​​this normal time, although he was a little rash , but this positive and enterprising attitude is worth learning from.”

Li Nan scratched the back of his head in embarrassment, and said with a little embarrassment: "There is no need to learn from me, it consumes too much of my comrades."

Fortunately, the person did not fall into any major accidents, patted the dirt on his body, and the classroom atmosphere was restored again.

But with such a small episode, the tension that was in the air before gradually dissipated.

Looking at the writing on the blackboard, Li Nan breathed a sigh of relief and read it seriously:
"The universe is so big, the particles are so small, the rockets are so fast, the chemical engineering is ingenious, the earth is changing, the living things are so dense, and the daily use is so complicated. Mathematics is everywhere."

As the last word fell, Cheng Nuo took the lead in applauding.

"Very good, the pronunciation is very accurate, and the emotion is also very strong, I will give you ten points!" Cheng Nuo smiled and nodded, then looked at the "injured" comrade before and said: "However, in view of Comrade Li Nan's ten points The table caused some minor troubles, in order to make up for him, add 5 extra points to the same table, do you have any objections?"

Li Nan shook his head again and again: "I have no opinion, it was my mistake."

"That's right." After getting a positive answer from Li Nan, Cheng Nuo looked at the others with a smile: "Do you have any comments?"

"No~" Everyone said in unison, looking at the two with faint envy.

Just as Li Nan breathed a sigh of relief and was about to sit down with a little happiness in his heart, he was stopped by Cheng Nuo.

"Wait a minute, Comrade Li, I haven't finished my sentence yet. Don't sit down in a hurry and talk about your understanding of this sentence. It's best to combine it with the scene of our shipbuilding." Cheng Nuo encouraged with a smile: "Yes That's right, this question is an additional question, and if you answer it correctly, you will also get extra points."

Li Nan's mind went blank for a moment, and he hesitated after opening his mouth for a long time: "Counting... Calculating the length of the hull requires mathematics..."

"What about the back?" Cheng Nuo asked.

"I don't know about it later." Li Nan shook his head, not daring to look directly into his eyes.

Cheng Nuo was a little helpless, so he had to raise his hand to let the other party sit down.

However, with the good start of Yimu Lixin in front, everyone behind spoke enthusiastically, with various ideas:
"Statistics can be applied in ship positioning to help ship positioning technology to accurately locate and facilitate ships to travel reliably. By collecting ship position data at different time points, the ship's driving route can be inferred and the ship's subsequent driving route can be predicted to ensure the safe driving of the ship... ..."

"There is also geometry, which can be used to calculate and draw the shape of the hull, the dimensions of the ship, the curvature of the hull, and so on."

"There is also the principle of trigonometry, by which the angle, distance, and height of a ship can be calculated and measured. For example, using trigonometry, the height of a ship's hull can be measured to determine whether the hull meets the design requirements..."

It seemed that everyone was chattering, but Cheng Nuo actually found that the answers were basically given by the Chinese laborers he brought back from Europe, and most of the knowledge was from the night school he founded.

The corridor in the middle of the classroom, like the border between the Chu River and the Han Dynasty, separated the Jiangnan Shipyard from the Chinese laborers going to Europe.

While talking more and more confident, while starting to feel a little downcast.

Watching the opponent keep adding points, the workers of the Jiangnan Shipyard, who originally regarded themselves as the masters, changed their original arrogance and began to feel a little restless.

The young man next to him looked left and right, and the more he looked, the more flustered he became, so he quickly closed his eyes and closed his eyes to the master master.

"Master, we have to do something, or we will be inferior to others in our factory in the future, what is the reason for this?"

The master sat firmly on the Diaoyutai, picked up the enamel cup slowly, blew off the tea foam on the water surface, sucked it for a while, and then said: "This is where to go, don't worry, besides, when foreigners controlled it, We have not been taught anything with technical content, how can we stand up and compare with others?"

After all, he is young, even with the guidance of the master, the young man still can't sit still: "But you have said it before, master, you can't sit and wait for death. Now we just watch people eat meat, that's not okay."

"Enough!" The master stared wide-eyed, covered the teacup with one hand and knocked it on the table: "What's the matter, you don't listen to me anymore? If you know everything, why do you need to sit here? Flutter your wings, people want to improve and study first, and only see the battle of spirits, what big things can they achieve? Listen to what people say!"

As he said that, the master took out a notebook and a pen from his waist and spread them on the table.

Seeing that the young man hadn't reacted yet, the master snorted directly: "Live and learn, and still don't listen carefully? If you really want to win, then study hard!"

With the master craftsmen making samples, even if they were dissatisfied in their hearts, these workers in the Jiangnan Shipyard began to correct their attitudes. No matter how provocative the Chinese workers going to Europe were, they would turn a deaf ear to them.

Cheng Nuo naturally saw everything below and remembered it in his heart. Knowing that this could not go on, he clapped his hands and stopped answering.

"Everyone's answers are very good, but for our shipbuilding industry at present, although mathematics can be used in many places, everything has a priority. Today we are going to learn the mathematical staking of the hull. So what is staking? Let the master with the most experience in shipbuilding present here answer it."

After saying this, Cheng Nuo took the initiative to applaud again, and looked expectantly at the master.

This time, the master master did not refuse, put down the pen in his hand, Shi Shiran stood up, cupped his hands around and said calmly: "Then I will throw a brick to attract jade. If there is anything wrong, comrades here are welcome to correct it in time."

Nodding at Cheng Nuo, the master said steadily: "The so-called lofting directly means to enlarge the design drawing drawn on a certain scale on the drawing into a 1:1 real-scale drawing. Of course, it may also be 1:5. :1, or even 10:[-], and so on.

In terms of shipbuilding, the purpose of lofting is to produce various parts of the hull, such as ship planks, keels, and ship bottoms.After the lofting is complete, each section curve of the hull is transferred to the appropriate material, where it is cut, riveted or welded to form the complete hull structure. "

"Well said, the master is indeed a master, hit the nail on the head!" Cheng Nuo walked up to the master himself, sat him down and said, "The hull stakeout is a crucial step in the shipbuilding process. It ensures the integrity of the hull design. accuracy and consistency.

Through staking, our hull designers can verify the curves and dimensions on the design drawings and convert them into actual construction instructions, making the hull construction work more accurate and efficient. "

Stepping up to the podium again, Cheng Nuo directly erased the famous mathematical quote and drew a smooth curve: "Put it in mathematics, it is easy to understand, it is used to convert the two-dimensional curve on the hull design drawing into the three-dimensional shape of the actual hull..."

Generally speaking, stakeout has two main purposes. The first is to make an actual check on the original design and modify the unreasonable or wrong parts in the design.

The second is to provide sketches, sample rods, sample boards, and sample boxes as the basis for construction for each subsequent process - blanking, processing, assembly, launching, sprinkler, etc.

Its work generally includes three parts: line lofting of the hull, structure lofting and shell expansion.

Take the 1-ton giant ship Cheng Nuo and the others are currently building as an example. Draw a line diagram of a 100-class ship at a scale of 0.5:50. mm.

In order to avoid mistakes in the middle, Cheng Nuo deliberately selected some more practical mathematical principles and calculation methods, summarized them, and taught them to the comrades present, so as to carry out manual mathematical stakeout.

The several order function derivative value of the spline curve used in the mathematical lofting of the hull at each end point is the information of the spline curve, that is, the category of computational geometry.

Among them, the main theory of mathematical staking comes from Mr. Su Buqing, the founder of our country's school of differential geometry, who is known as "the brilliant mathematical star in the eastern country", "the first geometrician in the east" and "the king of mathematics".

At that time, Su Buqing was not in his prime, but he was still very concerned about the practical problems of production.He led his students to many factories, and later went to Jiangnan Shipyard to do hull mathematics lofting, and went to Shanghai Tool Factory to give classes to workers and technicians.

Solving the problems encountered in production for them has greatly improved the technological level and productivity of related industries.

Later, on the basis of the hull mathematical lofting project, Su Buqing founded the new discipline of "computational geometry" and opened up a new field of geometry research.Later, the Department of Mathematics of Fudan University won the National Science Conference Award for the "Mathematical Stakeout of Hull" and other projects.

Although many of them required the assistance of computers and were not suitable for Cheng Nuo at this time, there were still some contents of applied mathematics, which greatly helped Cheng Nuo and the others.

It was during this process of study and discussion that the Chinese workers who went to Europe and the old employees of the Jiangnan Shipbuilding Institute also began to gradually abandon the previous suspicions, and the relationship became more and more familiar. The master will often discuss with Wang Tiehammer about new techniques, and everything is developing in a good direction.

On the other side, Morgan, who "professes that he has contributed to construction", directly dismissed it, picked up his cigar and took a sharp puff:
"Jack, do you know where the cigars taste the best?"

Jack hurried forward and replied, "Of course the cigar in your hand tastes the best, sir."

"No, no, of course Cuban cigars are good, with a mellow fermented aroma. Only the fertile red soil in Cuba can breed the best tobacco in the world!"

The subordinate cooperated: "What you said is that only upper-class people like you are worthy of smoking such cigars."

All the smoke from Morgan's mouth was spit on the subordinate's face. Seeing that the other party dared not speak out, obviously angry but unable to get angry, he couldn't help but feel complacent: "Only our British Empire, where the sun never sets, can create The most advanced ships in the world, the French? NO, the Chinese, NO."

Morgan laughed out loud after saying this, especially after listening to his subordinates report on the progress of the shipbuilding, he felt that the victory was in his hands, and everything in front of him was nothing more than chickens and dogs.

The subordinate was not as optimistic as Morgan thought, he hesitated, and finally decided to tell the story of Cheng Nuo's lecture: "Sir, I heard that the Chinese side has started special shift training, should we also conduct training? ?”

Morgan didn't care: "That's because they don't understand anything, so they need training. We have a lot of experience, so how can we use it like them? It's a waste of life meaninglessly, God and even the elderly can't stand it." of."

Before his subordinates could react, Morgan suddenly thought of something funny: "Also, with the ability of us British, it seems that everyone can be a teacher to the Chinese in the past. In this way, are we too bullying? They are dead, or should I send a few colleagues over there to carry out humanitarian assistance?"

Originally, the subordinate wanted to tell Morgan that Cheng Nuo's training was not only successful, but also that the construction progress was on par with the British's, and even faintly surpassed. It was not what Morgan imagined.

But thinking of the other party's arrogant look just now, the subordinate's heart was rekindled.

"Poor guy, don't you know that this place is not under the jurisdiction of God?"

(End of this chapter)