I Have a Research Support System

I'm back.

Chen Wanqing came back from Teacher Wei's office with a smile on her face and seemed to be in a good mood.

Sister, what are you so happy about? Xu Qiu asked.

It's been almost a year since I came here, and it's finally about to open this time. I've done a job recently, and now the main framework has been established.

After showing the repaired picture to Mr. Wei, he was quite satisfied and asked me to start writing the article, but I guess I can only post a small article. Chen Wanqing said.

Congratulations, senior. Xu Qiu said.

By the way, I have almost mastered the operation of cleaning the substrate. Can you teach me some new experimental operations? Xu Qiu pointed to the petri dish with the substrate.

Okay, just recently I may need to add some data. After I teach you, you will understand... Chen Wanqing stared at Xu Qiu with wide eyes.

Understand, understand, senior sister's business is my business. Xu Qiu hurriedly responded.

Okay, it's a deal, let's teach you how to use the glove box first. Chen Wanqing smiled.

[The glove box skill is detected, is it recorded? 】

Record.

…………

This huge box is the glove box. It is very airtight, with a transparent explosion-proof glass on the front and iron sheets all around.

On the explosion-proof glass are two rubber gloves protruding outwards, through which the operator can reach into the inside of the box to perform experimental operations in the box. Chen Wanqing said.

Xu Qiu noticed that diagonally opposite this glove box, there was a larger glove box with three rubber gloves attached to it, so he asked:

Senior sister, there is also a glove box over there. They should be used to make solar cell devices. Why are they separated? Is there any particularity?

Actually, it's best to put them together, but we don't have enough space in the laboratory, so we can only put them like this. Chen Wanqing said.

Xu Qiu nodded, and then carefully looked at the box in front of him. It was about 1.6 meters long, 2 meters high, and about 1.2 meters deep from front to back.

He roughly estimated the price of the glove box in his mind.

Iron sheets, explosion-proof glass, and rubber gloves add up to a few thousand yuan less in material cost.

However, after the finished product is made, the price must be doubled several times, and it must cost tens of thousands, so let's ask.

Sister, how much is this glove box?

The two sets cost more than 380,000. Mr. Wei knew the boss of the manufacturer and gave him a discounted price. There are not many manufacturers in China that can make glove boxes. This one happens to be in Shanghai. Chen Wanqing said. .

It actually costs 200,000 yuan for one unit. I thought it would only cost tens of thousands. It seems that when I estimate the price in the future, I will add 0 after the estimate, and it will be close to the real price. Xu Qiu sighed.

Scientific research is such a waste of money, and you will get used to it after a while. Chen Wanqing smiled lightly, and then continued to introduce:

The atmosphere inside the glove box is nitrogen, argon and other inert gases. We use a nitrogen atmosphere. If it is a lithium battery, you must use argon.

The use of nitrogen is to create anhydrous and oxygen-free conditions, so that the reliability and repeatability of the experimental results obtained are high, because some materials in the battery devices we made are sensitive to oxygen and water.

You can see the numerical control panel here, which shows the real-time content of water and oxygen in the box, which are now less than 0.1ppm.

During the experiment, it may rise to about 10ppm, which is not a big problem.

However, if it is kept above 100ppm for a long time, it will have a great impact on the experimental results. Chen Wanqing said.

Xu Qiu knows that ppm stands for concentration in parts per million, which means that the proportion of oxygen molecules and water molecules in the glove box is less than one part per million.

The glove box is connected to the nitrogen cylinder through the gas pipeline, which can replenish nitrogen at any time to prevent air backflow due to insufficient internal pressure of the box.

After Chen Wanqing finished speaking, she led Xu Qiu to the two cylinder cabinets in the corner of the laboratory.

The cabinet body is painted with eye-catching yellow paint, and yellow and black warning tapes are pasted on the floor.

The senior sister opened the steel cylinder cabinets, and Xu Qiu saw two steel cylinders in each cabinet, a total of four steel cylinders.

We only have two cylinders, one is high-purity nitrogen, and the other is a 95:5 volume ratio nitrogen-hydrogen mixture. The former is used to supply gas to the glove box and nitrogen gun, and the latter is used to clean the glove box. Chen Wanqing said.

Afterwards, she looked at Xu Qiu seriously, and said, The operation of steel cylinders is dangerous, so before you are fully familiar with it, you must have me present to operate it.

Okay, senior. Although Xu Qiu has a system, he still nodded obediently.

This is high-purity nitrogen with a capacity of 40 liters, and the internal pressure is about 12.5 MPa. Because the pressure is too high, it cannot be used directly.

In order to solve this problem, the cylinder is usually equipped with a pressure reducing valve, which can reduce the pressure to 0 to 2.5 MPa.

In our daily use, the pressure range is 0.6 to 1 MPa, which is 3 to 5 divisions of the pressure reducing valve scale.

It is also very important to point out that if the main valve of the steel cylinder is loosened, the greater the pressure will be; on the contrary, the tighter the pressure reducing valve is, the greater the pressure will be. Chen Wanqing said.

Senior sister, the steel cylinder looks quite heavy, how did it get here? Xu Qiu asked while touching the body of the steel cylinder.

After placing an order in the school's laboratory management system, the drug warehouse will send a master to deliver the steel cylinders in time, and then install them before transporting the used empty cylinders away.

After studying the steel cylinder, the two returned to the glove box again.

There are two pedals at the bottom of the glove box, one is for pressurization, that is, to add nitrogen to the box, and the other is for decompression, that is, to pump out the nitrogen in the box and discharge it into the atmosphere.

The tank has an initial set pressure, usually 0.3bar, which is 0.3 atmospheres. When the pressure in the tank is lower than this value, it will automatically replenish air.

When the pressure is too high, the safety valve on the top of the box will be pushed open, and then the equipment will be forced to stop working.

This threshold is around 7bar, so be careful with the pressure gauge when using it.

But after you get familiar with it, you can judge the pressure by the feel without looking at the pressure gauge.

When you want to enter the box through rubber gloves, you must be slow to prevent the pressure from being too high and open the safety valve.

When coming out, it should also be slow to prevent the formation of negative pressure and cause air to enter.

Xu Qiu, try to operate it first. Chen Wanqing said.

...

After putting on the lab coat and taking protective measures, Xu Qiu began to try to put his hand into the glove box through the rubber gloves.

He first found the position of the ten fingers on the rubber glove, put it on his hand, and then slowly stretched it inside.

It was easy to enter at first, and as the hand advanced, the resistance he encountered gradually increased.

Seeing this, Xu Qiu lightly stepped on the decompression pedal, and heard a hissing sound of airflow, and the resistance gradually decreased as expected.

Continue to move forward, and finally entered the deepest point, with both arms fully extended into the inside of the box.

Xu Qiu felt it, because the rubber is very thick, and the operation is much more cumbersome.

Finally he slowly extended his hand and left the glove box.