Riding the wind of rebirth

"Oh yes, is this the paint box?"

"Yes." Zhou Zhi took out a magnifying glass and said: "The bottom of this box was rebuilt by Qianlong craftsmen, covering up some original traces, but not all of them were covered up."

"If we want to know the original appearance of these traces, we can only use scientific means. The first thing we think of is X-rays." While Professor Su was checking the bottom of the box, Zhou Zhi continued to introduce: "But X-rays contain radiation and are harmful to organic matter. Carbon [-] dating will cause irreversible effects, so we think we should avoid it as much as possible."

"I heard that Professor Su has infrared thermal imaging technology equipment here, so I'm here to disturb you."

"What is the temperature range that this box can withstand?" Professor Su is a very strict person. Thermal imaging must be related to temperature, so Professor Su asked this question.

"Hmm..." What is the temperature range that lacquerware can withstand?Mr. Qi and Zhou Zhi looked at each other, they really didn't know this.

But the general range is still pretty much the same. Zhou Zhi said: "Now in Liangshan Prefecture in the middle of Sichuan, everyone still uses lacquerware to make bowls and plates. They can serve soup and rice without any problem. They can definitely withstand the high temperature of [-] degrees."

"The elbow refers to the Yi people. In fact, there are also Xibe people in the northeast, and they are also masters of making lacquerware."

Qi Lao added: "The winter temperature in the Northeast is often tens of degrees below zero. Logically speaking, there should be no problem at [-] to [-] degrees below zero."

"That's easy." Professor Su breathed a sigh of relief: "Then it seems that this cultural relic is quite durable, right?"

"No, don't..." Zhou Zhi was so frightened that he quickly corrected: "If you can't bear it, you can't build it. We are just talking about a general range..."

"Well, let's start from minus five degrees, change to forty degrees, and take a look through the thermal imaging camera."

There is no problem with this temperature, but Zhou Zhi never forgets to remind: "Speed, Professor Su, don't change the temperature too fast..."

Professor Su placed the rhino-picking box in a device similar to a large box, then turned on the power, and a rough picture appeared on a screen on the workbench.

"Can you see clearly?" Zhou Zhi asked.

"This is surveillance." Professor Su was good-tempered: "The imaging camera can't see it now."

The assistant quickly adjusted the shooting position so that the three characters at the bottom of the bowl could be captured by the infrared camera at the best angle, and then closed the box: "Professor, let's start adjusting the temperature?"

"Let's begin." Professor Su nodded.

The process was quite simple. There was a buzzing sound inside the machine, and Zhou Zhi could see the light spots at the bottom of the bowl on the monitoring screen begin to change like clouds receding.

The screen displays from bright to dark. After reaching the initial temperature, turn on the low light, adjust the exposure rate, and then the assistant begins to heat up the environment inside the box. Zhou Zhi feels that the screen in the monitoring room begins to gradually brighten, just like the sunrise.

But the clouds are green.

The assistant tapped the button of the machine a few times at the right time, and the machine made a slight clicking sound. It was probably that the video was taken at the right time.

After a while, the box was reopened, and the assistant took out the paint box and handed it to Professor Su, and went to develop the film himself.

"Is this lacquer box very expensive?" Professor Su looked at the lacquer box: "Isn't this the kind of box that ladies in the north use to do sewing on their kangs? I've also seen plastic and glass ones, and they're both pretty good-looking. "

In the future, there will be melamine ones, which will look more like this!Zhou Zhi could only complain silently in his heart.

"At least it is an object from before the Qianlong Dynasty." Mr. Qi was equally unimpressed: "If the writing on it can be deciphered and it is as we expected, it will be very precious." "What you are guessing is Which words?"

"Zhang Cheng made, Zhang Fei's Zhang, achievements made, manufacturing made." Zhou Zhi said: "Zhang Cheng is the master of red and rhinoceros lacquerware in the Yuan Dynasty. If these three words can match Zhang Cheng's handwriting on the Forbidden City collection If so, this box should be from the Yuan Dynasty."

"Lacquerware from the Yuan Dynasty? How can it be so well-preserved?" Professor Su was a little surprised: "This really looks similar to the things on the kang of Northeastern aunts."

"This is the characteristic of lacquerware. After forming a complex with water molecules, it can stay as good as new for a thousand years." Mr. Qi said: "Don't talk about the Yuan Dynasty, even the ones unearthed from Chu tombs in the Spring and Autumn and Warring States periods All kinds of lacquerware are still well preserved.”

"The most exaggerated piece is the red lacquer wooden bowl from the Hemudu site in 500 BC." Zhou Zhi said: "Pottery, linen, silk, and lacquer are the earliest crafts in our country. Among them, silk and lacquer are two of the earliest crafts in my country. Unique to civilization, it was not until the rise of porcelain that the large-scale use of lacquerware was gradually replaced."

"Comrades who are interested in materials science can still dig into it. The anti-corrosion performance and adhesion performance are extraordinary."

At this time, Professor Su's assistant brought over a few negatives. The negatives were quite special and were as big as a six-page paper. Professor Su placed the negatives on the white frosted glass workbench and turned on the switch. The entire tabletop emitted a soft white light, making The content on the negative can be clearly seen.

Seeing the strange expressions on the faces of Mr. Qi and Zhou Zhi, Professor Su specially explained: "It is said that this table was invented by a child in Sichuan. Children nowadays are so smart. How do you think they figured this out?"

Mr. Qi laughed loudly and pointed at Zhou Zhi: "You have to ask him about this!"

"What do you mean?" Professor Su didn't understand.

"Hahahaha...because this smart kid you mentioned is sitting in front of you now."

"Ah? Did you invent this table?" Professor Su also laughed: "Isn't this a coincidence?"

"This was originally used for the elders in the family to restore calligraphy and paintings. Later, when it turned out to be useful, I ordered a batch for the school's Ancient Book Restoration Research Institute. Unexpectedly, they all came here..."

After Zhou Zhi finished speaking, he was about to stand up and look at the brand: "Let me see if the manufacturer has authorized it..."

"Sit down!" Mr. Qi quickly reprimanded. It depends on whether it's embarrassing for everyone if they find out it's a Sanwu product: "Business matters!"

Infrared thermal imaging has a halo effect and of course cannot be as clear as X-rays.

However, infrared thermal imaging also has an additional benefit, that is, it can capture the temperature difference changes of various parts in the temperature zone and reflect it through the depth of the color.

Nowadays, the film is still black and white, and the temperature difference is expressed as a change in grayscale.

In the normal temperature zone of ten degrees and thirty degrees, Professor Su adjusted the temperature change curve very quickly. In the film taken in this temperature zone, the temperature difference between the writing and the carcass is the largest, and the displayed text is also the clearest.

Of course, the specific optical technology is not clear, but at least on the three negatives, three characters can be seen clearly, which is indeed "Zhang Chengzao".

"I missed it again!" Mr. Qi patted Zhou Zhi on the shoulder hard: "Okay, I wouldn't have noticed it."

"That's your old eyesight problem, not your eyesight problem." Zhou Zhi said modestly: "I just thought that according to the level of paint work done by Qianlong, it would not leave any traces, so I was more curious."

"Lao Qi, why do you think the later painters left some traces for our descendants?"