"Hey, do you think there can be such a big gap between this person and people? At a young age, Professor Cheng not only knew mathematics, but also chemistry, and he also knew more than the average person."

"Do you have any misunderstanding of the word "understand", do people just understand, they can teach us as a husband, you are ashamed to say that you are not ashamed."

"I'm ashamed of the bird, I'm ashamed to be on the road for a while, not to mention the position in the front row, even the back row has to be robbed, maybe I have to stand in the aisle to listen in the end."

"That's it, not to mention that this course is still about synthetic ammonia, which I couldn't think of before~"

As he spoke, the steps of several people suddenly intensified, and they ran in the direction of the classroom.

And similar scenes also happened in all corners of the yard, lest I run too slowly and finally can't even squeeze into the classroom.

The reason why this happened is mainly because Cheng Nuo deliberately carried out a series of chemical knowledge assault courses within the Academy of Sciences in order to cultivate more chemical talents, involving acids, alkalis, and salts.

In addition to the people from the original Academy of Sciences, there are also some students from the Work-Study Society who are interested in chemistry.

Basically, they are all members of their own family and know their roots.

Combined with the experience accumulated in the previous alkali production, Cheng Nuo talked about these chemical knowledge easily, and explained while doing experiments in the middle, which completely opened up the new teaching mode of this class and stimulated many people's enthusiasm for chemistry.

Originally, I was just interested in Cheng Nuo, and I wanted to see how his attainments in chemistry were, but I never expected that Jing Chengnuo would be so up and down and directly interested in chemistry.

Jiang Jiangzuo ridiculed him after learning about this, saying that after the end of this series of courses, he must not find Cheng Nuo again, otherwise all good students will be taken to the "point of no return in chemistry", which will be a loss to grandma's family.

"Come on, let's let me go, Professor Cheng is here, everyone hurry up and let Professor Cheng go first."

With a few shouts, Cheng Nuo squeezed out of the crowd and spread the books under his armpits on the table.

Surprisingly, today's Cheng Nuo did not start teaching after a little review of the course as before, but took out a letter from his arms and lit up in front of the students:

"Students, do you know what this is?"

"Faith."

"That's right, this is a letter, a letter from across the Pacific Ocean, a letter from your chemistry senior to me, to you, to aspiring young people in China, and I will take him out today and read it to all of you."

Under the curiosity of the students, Cheng Nuo opened the envelope, took out the letter from it, and said in front of everyone:

"I've been in the U.S. for so long, and I've always had some Tsinghua students write to me and ask me to introduce my life in the United States of America.

It seems that with the word "beauty", this country becomes so beautiful, as if it is an ideal country in the world, but is this really the case, don't say it is beautiful, and it is not an exaggeration to describe it with ugly words.

Today, I will take this opportunity to tell you what happened to me, and I believe that with your talents and learning, it is enough to see the life of the vast majority of Chinese people in the United States through my shadow.

I still remember that the first place I came to the United States was Honolulu, when the steamer was docking for supplies, I thought that I would finally dock, just to take advantage of the island to have a good look at the scenery, but I didn't expect that the local guards would not let the Chinese go ashore and never let me get off the ship.

Thanks to the ship's first mate, we were able to stay on the island for a few hours, but even so, every time we passed through an intersection, we had to be checked for a while, and then we carefully calculated that the time spent on the island was not as much as the inventory.

And that's not all, when we return to the ship, we have to check again, and we don't forget to count the number of people, why are they so serious, it's because they are afraid that we will stay on the island as islanders.

The so-called Wendao steamer arrived in Danshan, and it was very difficult for the Chinese to land on the shore

, the most sad is the Chinese country, and people everywhere look at it coldly.

Some students will definitely say that the United States is so big, this kind of thing may be just accidental, but what I want to say is that as long as you set foot in the United States for one day, we will be discriminated against as Chinese sons and daughters for one day, even if we wear suits, bow ties, and high-class looks, we are still insulted and teased.

Walking on the street, you will be ridiculed from time to time (stupid).

In particular, the modesty and prudence that we are often accustomed to be proud of are considered to be a "non-resistance" and "compromise" nation in front of foreigners.

What impressed me the most was that several of our fellow villagers went to a small factory in Canada with Americans for internships, and every time we went back, we had to be harassed, and then we were forced to have no choice, so we directly asked the teacher to lead the team.

But even so, the border police still refused to let us go, whether it was the overseas Chinese card, the university emblem, or the teacher's testimony, they refused to let us go, thinking that our identity was fake, and even the single clothes we were wearing had to be checked for half a day, thinking that we could not afford it, and they wanted to detain us on the grounds that we had no receipt......

In addition to the fact that part of the treatment of these inferior residents is that we Chinese are too timid and afraid of things, a large part of them is because our country is too weak to shelter its people.

The minister to the United States doesn't know this, of course he does, but does he have a way, no! His eyes were closed, his ears were covered with cotton, and he was shrunk together to cover his ears and steal the bell.

Like our neighbor Japan, the treatment is a little unfair, and the effect is very different.

Foreigners who are even slightly aggrieved in China immediately report to their consul and ask for negotiations with our official family, and if they are more angry, they will directly appeal to their own minister and negotiate directly with Beijing.

This government is a government, and the people are happy to have their government.

……

Having said so much, it can be summed up in one sentence, the country's poverty is the original sin, whether it is at home or abroad, it can't shelter its people, only when the country is strong, the ugly country will become a kind "America", my generation should be self-reliant!"

As soon as the letter was read, the faces of everyone in the classroom were generally full of solemnity.

Those who were in intense emotions were directly so angry that their faces turned red, and their knuckles were pinched and creaked.

"Professor Cheng, is everything written in this letter true, is it really so miserable for our compatriots to live there, everyone cares."

"Yes, Professor Cheng, we all know that you are also in the United States, no, it is an ugly country, you have studied in an ugly country for so long, and you have lived such a life?"

"It's really unbearable, it's unbearable!"

Cheng Nuo handed the letter to the students who walked up to the stage and handed the letter to the students in the first row for everyone to circulate to each other.

Looking at everyone, Cheng Nuo took a long sigh and said slowly: "I can only say that the situation is more serious, I won't talk about the killing of overseas Chinese in Mexico, and the near Shandong has been encroached upon by foreign powers, I believe everyone can also see it, the country is still not guaranteed, let alone overseas?"

After a pause, Cheng Nuo said earnestly: "The country is poor and weak, and her people will not be looked down upon wherever they go, I think everyone can understand the purpose of our study, Yu Gong, for the prosperity and strength of the country, for themselves, and for straightening their waists."

After saying this, the students have a better understanding of the meaning of learning.

However, some students were still curious: "Professor Cheng, which senior wrote this letter?"

Cheng Nuo smiled: "This, isn't it written on the payment, Hou Debang."

The student was pleasantly surprised: "Is that Senior Hou Debang who scored 1,000 points in 10 homework in the Tsinghua entrance exam?"

[In view of the general environment,

Cheng Nuo nodded: "Except for this, I'm afraid there is no second person."

Seeing that the scene was about to riot again, Cheng Nuo hurriedly stopped: "Okay, put aside the letter for the time being, let's start the formal class, first ask a few classmates to stand up and come back to the homework I assigned after class last time......

It is said that Hou Debang is the first generation of scholars at Tsinghua University, and he has already participated in the work

He felt that his youth should not be like this, so he resigned and went to Tsinghua University to study in the United States Preparatory School. It was in this entrance exam that Hou Debang became a well-known figure in Tsinghua Park with an excellent score of 1000 in 10 subjects.

In 1913, Hou Debang was escorted by Tsinghua School to study chemical engineering at the Massachusetts Institute of Technology in the United States.

Because Fan Xudong had written to him before, Cheng Nuo took the opportunity to ask Hou Debang to write a letter to these juniors to motivate them to study hard.

Maybe it's because of Cheng Nuo's openness, no matter what they do, they seem to be able to succeed, so that these students blindly have some more arrogant ideas, take things too seriously, and think that the world only looks at talent and nothing else.

Cheng Nuo just wanted to use Hou Debang's own experience to warn these students with forked thoughts, lest they really take the wrong path in the future.

It's too smooth, it's too perfect, it's not a good thing.

"Okay, let's put aside the review for now, let's start a new lesson, and the theme of this issue is "Ammonia."

After hearing the question, the students in the audience were quietly relieved, but after hearing that they were going to talk about new knowledge points, their hearts tightened a little bit.

Seeing everyone cheer up again, Cheng Nuo nodded with satisfaction and began to teach seriously:

"Scientists have found that nitrogen is one of the most important components of plant nutrition, and it is the most important nutrient for plant growth.

However, most plants cannot directly absorb nitrogen in the air, and only when nitrogen is combined with other elements can it be absorbed and utilized by plants, so it is necessary to convert nitrogen in the air into nitrogen compounds, and the process of converting free nitrogen in the air into nitrogen compounds is called fixed nitrogen......

In fact, there are two methods of ammonia fixation in nature, one is to rely on nitrogen-fixing microorganisms to convert nitrogen into ammonia for plant absorption, and the other is to rely on natural energy such as lightning to convert nitrogen into ammonia, but this method cannot be used by manpower and is inefficient.

Later, in order to explore more efficient nitrogen fixation methods, the German chemist Haber successfully researched the method of synthesizing ammonia by the reaction of nitrogen and hydrogen in 1908, which is still the most widely used and economical nitrogen fixation method at present.

In addition to being used in chemical fertilizers, ammonia can also be used to produce dyes, pharmaceuticals, kerosene, soda ash, synthetic fibers, synthetic resins, etc.

The most important thing, and what Cheng Nuo sees the most, is that in the defense industry, ammonia is the raw material for the production of explosives, and missiles can be produced as propellants and oxidizers for rockets.

Especially in the current World War, ammonia, as a raw material for the explosives industry, has been used in large quantities to serve the war effort.

As early as 1913, the German Oborg-Baden Aniline Soda Ash Company built a set of 30t per day ammonia plant, which is the world's first ammonia production unit to achieve industrial production.

At the same time, we did not begin to have our own synthetic ammonia plant until the 30s of the 20th century, and even then, the scale was quite small and could not meet domestic needs at all.

Of course, this means that Cheng Nuo has great potential for development, but the difficulties in the initial stage of development are also unimaginable.

In particular, ammonia is synthesized by hydrogen and nitrogen under the conditions of high temperature and high pressure catalysts, so it is necessary to select suitable raw materials and go through a series of processing processes to complete the production of synthetic ammonia.

Hydrogen cannot be obtained directly from other mixtures, so the most important issue in ammonia production is how to obtain pure hydrogen.

After the steps of ammonia synthesis are simply disassembled, they can be divided into three parts, namely, the preparation of raw gas, the purification of raw gas, the compression of gas and the synthesis of ammonia.

None of the processes in the middle are simple, especially in the final step of ammonia synthesis, which requires a mixture of nitrogen and hydrogen to synthesize ammonia under the action of high temperature and high pressure and catalyst, how to accurately obtain synthesis data is a rather difficult and dangerous process.

But what are the best high temperature and high pressure conditions? What kind of catalyst is best?

These all need to be calculated and experimented by Cheng Nuo.

In the middle, because of the temperature and pressure, the synthesis device explodes at every turn, which is very dangerous.

Fortunately, after several failures, Cheng Nuo had experience, on the one hand, please continue to improve the process, on the other hand, he asked Tesla to come forward and participate in the design of the chemical design synthesis device, and finally solved the problem of high temperature and high pressure resistance of the equipment by adopting a double-layer structure.

Finally, looking at the sample, Cheng Nuo became more familiar with it the more he looked at it, and finally after thinking about it carefully, he blurted out:

"Isn't this the thing that Bosch designed, because it won the Nobel Prize in Chemistry in 1931, no wonder the more I got to the back, the more familiar I became, and it turned out to be based on the drawing."

Tesla was a little puzzled: "Cheng, what are you talking about?"

Cheng Nuo haha: "I'm saying, Mr. Tesla, your Chinese is getting better and better."

"It's over."

"Hey, yes, don't you consider learning our dialects, such as Sichuan?"