A huge classroom,

Yang Xiaoman was talking about his family history on the stage, as well as the case of using finance to like foreign markets, while Xu Mang was sitting in a corner, dozing off boredly, unable to imagine that there were so many students coming to listen to the lecture for such an airport woman.

Hell...

I feel that Xiao Man is much more well-known than himself, what's the situation? Shouldn't these people be more fascinated by themselves?

What's going on?

Xu Mang took out his mobile phone and took a picture of his face, and found that he was still so handsome, even more handsome than before, he was young and frivolous in the past, and he had the feeling of chasing the wind, but now he has a little more maturity and stability, I have to say... It's just handsome.

In boredom,

Xu Mang took out a pen and a notepad from his bag, and began to study the application of perovskite in solar energy, of course, it is inseparable from mobile phones, and some information needs to be found on the Internet, although a large amount of information is still copied in the brain, but the database has been updated, and he is usually so lazy...

According to the tandem structure proposed by Xu Mang, from the perspective of solar energy, the important property of these materials is that the incident light causes the negatively charged electrons to enter a higher energy state, leaving vacancies or holes, which act like positively charged particles.

If these charged electrons and holes can avoid recombining and reach the electrodes above and below the perovskite membrane for a long enough time, the current can flow.

Theoretically,

However, there are many problems, for the time being, there is no strength to make large-size, high-efficiency battery grids, and the problem is that it is more difficult to produce uniform coatings on larger sizes, but Xu Mang proposed to use transparent electrode films to collect current.

As it turns out, these electrode films allow a lot of light to pass through, but they also have a slight resistance that blocks some of the current, which is even more problematic at larger sizes, and doesn't allow for the same increase in area and conversion as silicon panels.

Xu Mang made a simple calculation that the efficiency of a perovskite cell of 6.25 square centimeters was 20 percent, but when the 35 grids were combined into a 412 square centimeter module, this proportion dropped to 12 percent.

But...

Despite this, perovskite cells are easier to produce and cheaper than silicon cells, and Xu Mang has investigated the process of making silicon, which requires heating at 1,800 degrees, and dissolving the material in hydrochloric acid at 300 degrees Celsius when preparing high-purity slabs.

On the contrary,

Perovskite cells only require an inkjet printer to deposit a small amount of material onto a plastic film.

"Ugh..."

"It's so annoying!" Xu Mang sighed, if it weren't for his wife, he would have torn off these contents earlier, it is not easy to be a man, and it is even more difficult to be a man of Xiaoman.

What to do?

What else can I do, who let myself marry such a woman.

Aside from the conversion rate of perovskite cells, its lifetime is also a big problem, and the silicon plates currently in service have 25 years to live, but can perovskites reach this time?

On the other hand,

Perovskites are also very sensitive to air and moisture, but this can be protected with transparent materials, and the most serious thing is the crystal structure of the perovskite itself, damn it... In some cases, perovskites undergo structural changes after heating, which are reversible but still affect power generation efficiency.

Xu Mang was desperate,

The question is a bit difficult, anyway... Let's talk about it back home.

In the following time, Xu Mang was very tormented, the ghost knows how to spend it, when the classroom was over, Xu Mang was woken up by Yang Xiaoman, raised his head and looked around, and asked in confusion: "What about people? Why are there no people?"

"It's over!" Yang Xiaoman said angrily: "Old lady, I'm in class, didn't you listen to a word? Do you know how long I was preparing last night? You big pig's trotters... Don't respect me at all, I'm!"

"Ahem..."

"I can't help it. Xu Mang said embarrassedly: "What should I do if I don't understand?" I'm so honest, I automatically fall asleep if I don't understand, and I say... Did you give any money for the speech?"

"Nope. ”

"But give me the position of honorary professor. Yang Xiaoman said seriously: "I have an open class tomorrow, to speak... You stay with me, otherwise I'll be nervous, you don't want to see your wife suffer from depression because of nervousness, right?"

Xu Mang: @#¥%......%

I...

OMG!

Two days were wasted, but the vacation could be extended.

Leaving the classroom,

Xu Mang and Yang Xiaoman planned to go to the attractions in the afternoon, but when they passed by the Mathematics, Physics and Life Sciences Building, Xu Mang was suddenly stunned, and there was a blackboard next to the door, which was empty and empty.

"What's wrong?" Yang Xiaoman asked, "Is there a problem?"

"The blackboard says the smartest problem solver and the best problem solver. Xu Mang frowned and said seriously: "Isn't there no genius in this university?"

"What do you want to do?"

"Don't make a fuss... If you are in a foreign land, you have to follow the customs of the country, in case someone else takes a machine gun and kills you 'Tututu' the next day. Yang Xiaoman stood on tiptoe, gently pinched Xu Mang's ears, and said gently: "Good... Otherwise, I'll beat you, old lady. ”

Alas...

In the gentlest tone, in the most vicious words.

Damn it!

However, Xu Mang has always been rebellious, otherwise he would not marry Yang Xiaoman, silently picked up the chalk, and then wrote down a formula, the process took only half a minute, turned around and said with a smile: "Let's go..."

"This..."

"What is this?" Yang Xiaoman asked with a confused expression, "What kind of demon did you start doing again?"

"A mathematical equation. ”

"The Chan-Hardy-Littlewood theorem is needed. Xu Mang said indifferently: "Although it has not yet reached the world-class difficulty, it is enough to make the science students, professors, scholars and experts of Pacific University confused for half a year." ”

"Cut!"

"I don't believe it, old lady. Yang Xiaoman said disappreciatively: "You are not the smartest in the world, I believe there are others who are smarter than you." ”

After that,

Suddenly sprinkled dog food, held Xu Mang's prosperous beauty, his eyes exuded a strong love, and said seriously: "But you are the only genius in my mind!"

"Let's go!"

"My knight, Princess Ben wants to eat rainbow ice and ginger ale!"

...

Afternoon

A professor who is engaged in mathematics research, Dwyke, took his own materials to the Mathematical Physics and Life Sciences Building, and as soon as he entered the building, he saw the blackboard next to him full of contents, which made the mathematics professor stop.

It's been almost a year,

Although the idea was brought up two years ago, it only lasted for less than a year, and then everyone's enthusiasm dropped, and the lack of reward mechanism made many people lose motivation.

unexpectedly

It reappeared.

The professor took a few steps to the blackboard and saw a not-so-complicated equation that he didn't pay attention to at first, but when he was about to solve it, he suddenly realized that it was not as simple as it seemed.

"Huh..."

"Who wrote this?" Professor Dwye Ke's scalp was numb at this time, and the more he went deeper, the more he felt that this equation was not simple, and it had completely exceeded the scope of his understanding, logically speaking, it was not like it was written by a student, but there were not many professors engaged in professional mathematics, after all, Pacific University was weak in academic and natural sciences.

Damn it

Who wrote the bastard's equation?

Professor Dwieske picked up his phone, took a picture of it, and emailed it directly to a friend of his, who is a professor of mathematics at Princeton University, and can be a professor in the mathematics department of Princeton, where the madmen are all running wild.

Long

When Professor Dwiek returned to his office from the professor, suddenly his cell phone rang, it was his friend.

"Dwike!"

"It's... Is this what you came up with?" the professor of mathematics at Princeton University, with a hint of surprise in his words, hurriedly asked, "This... It's very difficult, and I just studied it with other professors in the Department of Mathematics and found that... Multiple proofs are required. ”

"You can't do it?" Dwiko asked in surprise, "I know it's hard, but I'm a little surprised that it can be difficult for you." ”

"Anyway..."

"Did you come up with this?" the professor asked.

"No!"

"I don't know who wrote it, I asked everyone in the math department, and no one admitted it. Dwiko suddenly thought of something and hurriedly said, "That's right... Professor Xu Mang from Huaguo is on vacation in Hawaii, and his wife is giving a lecture at our school. ”

“...”

"It must be him!"

"It must have been written by Xu Mang. The professor said solemnly: "Ordinary people can't think of such a difficult equation, oh my God... If you do, be sure to ask him for an answer, and we people are anxious right now. ”

"Good!"

Hang up the phone,

Dwiko showed a wry smile, he should have thought that this was written by Xu Mang, a person who can achieve such a high level of achievement in physics, this mathematical talent will not be too bad, after all, he is engaged in theoretical physics, which is full of a large number of mathematical calculations.

meanwhile

Princeton University,

The math professor was quite speechless, I didn't expect Xu Mang to go to Hawaii, and he gave you a math formula, which... This guy is a real headache, however... Although this professor is quite helpless to Xu Mang, he is very honest.

silently posted this calculation on his Twitter, telling others that this is the calculation given by Xu Mang, hoping that someone can solve it, and then attached Xu Mang's current coordinates, located at Pacific University in Hawaii.

In less than an hour,

This tweet exploded directly,

By the way, there is also the University of the Pacific that I don't know what to do.

The president of the University of the Pacific received numerous phone calls, begging him to keep Xu Mang, at least the damn answer.

......