A few days after returning home, it was already time for Zhang Lan's first grade of primary school to officially report, which was a big deal, Zhang Zongjun didn't care how reluctant Zhang Lan was, and Yang Zhi escorted Zhang Lan to report to school.

The first grade is really a good place, except that the teacher is not a familiar teacher before, almost all the classmates are familiar little guys before, thinking about staying with these little broken children with snot for five years, Zhang Lan can't help but have a headache: How can I live this day?

Fortunately, Mo Liyan, who is as cute as a porcelain doll, is still Zhang Lan's tablemate, which finally gave Zhang Lan's sad heart a little comfort.

Everything is normal in the company, and there is nothing to do with Zhang Lan, and Zhang Lan is not willing to go around all day to be an eyesore. Zhang Lan and Mo Liyan were fighting when they got out of class, Mo Liyan listened carefully during class, and Zhang Lan slept seriously, and the division of labor between the two was very clear. Zhang Lan who sleeps is really honest, and there will be no indecent performances such as snoring and drooling at all, and the teachers are also very cooperative with Zhang Lan sleeping in class: As long as you don't make trouble in my class, you can do whatever you like, as long as you are stable, we will have Emei tofu.

The only one who can control Zhang Lan is Xiao Chenxi, this girl has now become the substitute head teacher of Zhang Lan's class - there is no formal, this substitute class teacher is considered a class teacher - but unfortunately the principal's idea of using Xiao Chenxi to manage Zhang Lan has not been realized, although he has no interest in making trouble at school, but Zhang Lan still either falls asleep in class, or writes something on a piece of paper that no one knows what it is.

Just like this, day by day, when I am happy, I go to class, and when I am very bored, I take Mo Liyan to skip class together, and the life is comfortable. Mo Liyan, this girl was taken by Zhang Lan, the little girl who never skipped class before, was instigated by Zhang Lan to skip class in fear from the beginning, and then followed Zhang Lan to skip class unscrupulously, and finally developed to pull Zhang Lan to skip class, the change is so big that Zhang Lan is a little suspicious that this girl is still the little girl who only knows how to study when she first met and sees her admiration?

Time is gradually entering autumn in the careless wandering day by day. The autumn is high and cool, the leaves are just beginning to wither and yellow, and on this day, Zhang Lan, who skipped class, is squatting on the street with Mo Liyan. One person ate ice cream deliciously, Zhang Lan looked at the crowd of people coming and going in front of him, and struggled to find scarce beauty resources from the crowd to satisfy his eyes, at this moment, the two saw a car running and suddenly smoke began to smoke in the engine compartment.

Zhang Lan was taken aback. Suddenly stood up, what is going on? Could it be the legendary spontaneous combustion of the car?

Seeing that smoke began to rise from the engine compartment, the driver of the car quickly stopped the car, took out the fire extinguisher from the trunk and opened the engine compartment cover.

At the moment when the engine compartment cover was opened, although it was a little far away, Zhang Lan still clearly saw that the engine compartment, which was originally only smoking, was opened to the engine compartment, and when the engine compartment cover was opened, the things that were not burning violently were flamed after encountering a large amount of oxygen in the air. Despite the driver's best efforts to spray with a fire extinguisher, it was still to no avail. The owners of several shops around the area obviously also saw the situation in front of them, and rushed out of the store with a basin, but the fire was still too big, and when everyone put out the fire, the cockpit was fine, and there was basically not much left in the engine compartment except for some things that could not be touched, such as the engine.

Zhang Lan didn't go up to help, not only could she not help when she passed, but she would also be kicked aside by a group of people who were anxiously busy helping to put out the fire as a hindrance. But seeing the spontaneous combustion of the car, Zhang Lan was a little strange. The natural phenomenon of automobiles generally occurs more in summer, which is generally because the temperature in the engine compartment of the car is relatively high in summer, and the parts that are easy to catch fire such as wires age quickly, and if the sealing system of the vehicle engine has a slight problem, there is a leakage of fuel or lubricating oil. It is easy to spontaneously combust in summer, but now it is autumn, and the temperature is much lower than in summer, why does this car still spontaneously combust?

The steaming engine caught Zhang Lan's attention, and the hot air was because the engine was too hot, and the cold water poured on it evaporated when it was hot.

The car has been parked for so long. After everyone even poured water on the fire extinguisher, the engine was still so hot, what happened?

Zhang Lan seemed to feel that she had caught something, but the thought in her mind was like a naughty child playing hide and seek with herself, and she couldn't catch it!

"This broken car," the hapless driver complained loudly because he had such an unlucky thing to do, "fuck, why is the heat dissipation so bad?!" I cleaned the radiator two days ago, but I didn't expect it to be like this in two days! ”

Poor heat dissipation?!

Zhang Lan's head was excited, and he suddenly remembered the material of the current engine, and now the material of the automobile engine is generally cast iron engine, and the heat dissipation of the cast iron engine is of course very poor!

Material! Zhang Lan slapped her thigh heavily, and in a trance, it seemed that there was no feeling on her thigh, but Zhang Lan, who was excited, didn't notice this: it was the material of the engine!

Cast iron engines have many innate performance deficiencies, such as large weight, poor heat dissipation, high friction coefficient, etc., among which heat dissipation is the main reason for spontaneous combustion of automobiles! In order to solve this problem, major automobile manufacturers have tried all means to solve this problem, and the simplest and most complex way is to use new lightweight materials with good heat dissipation to make engines!

The reason why it is simple is because as long as you find the right material, the production of a new type of engine will bring a huge leap in technology, but it is difficult, and it has its own unique difficulties, which material is more suitable as the material of the engine? There are a lot of things that can be used to make materials for engines, but if you count alloys, it's even more!

Although this engine still has various shortcomings such as poor corrosion resistance, low strength, high cost and so on, the advantages are also obvious, that is, the weight of the engine is nearly half lighter than that of the cast iron engine, and the heat dissipation performance of the engine has been greatly improved!

On an all-aluminum engine, spontaneous combustion has never occurred. Of course, an all-aluminum engine is not the best choice, and its low top speed and low engine body strength make it unsuitable as a representative of high-performance engines. However, at this stage, it is the most suitable new generation product as a replacement for cast iron engines in terms of economy and practicality.

Foreign automobile giants have begun the research of all-aluminum engines, and now there is basically no engine with independent intellectual property rights in China, and the research of all-aluminum engines is impossible to talk about, but one thing can be believed, that is, domestic people of insight have realized that this new type of engine has broad prospects. It's a pity that these people of insight are the ones who don't count.

To make an all-aluminum engine, the most important thing is to solve the problem of materials and heat dissipation, the temperature limit of the best super heat-resistant alloy can not exceed 1093 degrees Celsius, the temperature limit of steel and cast iron is 450 degrees Celsius, and the heat resistance limit of aluminum alloy is only 350 degrees Celsius. Compared with cast iron engines, its heat resistance limit is too low, which inevitably puts forward higher requirements for heat dissipation.

Now the engine used in their own motorcycle, the material is still cast iron engine, even if it is a relatively high-end Alice Ducati (Diana MARK5), its material is mainly cast iron, just for more beautiful, the shell parts of the engine and some parts with relatively low strength and temperature requirements are made of polished aluminum alloy material, even so, the weight of this engine is much lighter than before, and the appearance is more beautiful than the original cast iron engine after treatment, It also feels more upscale. This is also the reason why a motorcycle that costs more than 80,000 yuan is still in short supply.

The Institute of Metal Materials of the Chinese Academy of Sciences is probably at the forefront of metal materials in China, and the research level of metal materials here represents the highest level in the field of metal research in China!

Just when Zhang Lan was thinking about it, her ears suddenly hurt, and she felt as if she had been made a cycle of movement three times left and three times on the right.

Zhang Lan, who came back to her senses, held back the pain and squinted her eyes, but suddenly found that it was none other than Mo Liyan, who was eating big ice cream with her just now.

"Girl, are you crazy?" Zhang Lan was a little depressed, when did this girl become so savage? "What are you doing twisting my ear?"

"What are you doing with twisting your ears?" Mo Liyan's face was angry, "You're embarrassed to ask me, let me ask you, what did you mean by you slapping my leg so hard just now?" As he spoke, he couldn't help but reach out and rub his leg a few times, obviously the place that was photographed by Zhang Lan just now still hurts.

Yes? Zhang Lan smiled helplessly, no wonder she didn't feel pain when she filmed it just now, she didn't care about it, she thought she was too excited to ignore it, it turned out that her feelings were on this girl's legs!

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