I started with a ship full of max-level veterans, and I'm just a complete noob.

The letter made a slight scraping sound as it was pulled out.

Six pages of airmail paper, as thin as cicada wings, were unfolded in Zhou Changlin's hands. In the upper right corner of the first page was Qian Xuesen's usual blue-black ink fountain pen handwriting, so neat it was almost like printed text.

Zhou Changlin's gaze swept down from the first line. The tensor decomposition of shear stress was written at the beginning, followed by the Green's function construction of the interface displacement field. The integral kernel was the Mindlin solution of a semi-infinite elastic body.

He had read about this approach in Leningrad; it was used in the textbooks of the Institute of Mechanics of the USSR Academy of Sciences to deal with the problem of thin film peeling, but no one had ever applied it to the analysis of the cooling process of electron tube coatings.

He turned to the second page, where the expansion of the Green's function under the temperature gradient was written out one by one, with concise physical annotations next to each step.

Ma Gong also came over, and their eyes simultaneously fell on the middle of the third page.

The integral path of thermal expansion mismatch strain is clearly written as the definite integral from the sintering temperature to the target cooling point.

Zhou Changlin moved the letter an inch to the left with his right hand, making it easier for Ma Gong to see, but his own gaze had already slipped to the fourth page.

On the lower half of page four, the simplified expression for the critical temperature after integration is enclosed in a box.

The number in the box is 378.5 degrees Celsius.

His hand remained still as he turned the pages of the letter, his gaze shifting from the letter to the blackboard.

On the blackboard, Jiang Ming's derivation followed a different path.

Starting from the thermal activation energy of dislocation climb, and through the exponential decay function of the Pell's stress and the dislocation density constraint of the Holpage relation, he finally solved the critical temperature under the condition that the interfacial stress equals the fracture toughness of the coating.

That number was written in the box on the right side of the blackboard.

378.5 degrees Celsius.

There are two paths: one entrance is through elasticity mechanics, and the other entrance is through dislocation dynamics.

The mathematical tools used in between are completely different; there is no room for copying between the Green's function and the exponential decay function.

But the destination is the same number.

Zhou Changlin neatly folded the six pages of letter paper, placed them back on the table, and laid his hands flat on either side of the paper.

The silence lasted long enough for the heating pipe to make three water hammer sounds.

When he spoke, his voice was calmer than ever before.

"Two independent paths, different mathematical tools, converge to the same critical temperature."

No one responded in the meeting room.

"This is called self-consistency in physics."

After Zhou Changlin finished stating his conclusion, he touched the pen in front of him with his finger, then pulled it out of his breast pocket and unscrewed the cap.

Ma straightened up, returned to his seat, closed the tattered Soviet manual in front of him, pushed it aside, and didn't touch it again.

Liu looked down at the table, unconsciously rolling up and smoothing out the corner of the copy of the report in front of him. After repeating this three times, he finally put his hands under the table, leaned back in his chair, and stopped moving.

Zhou Changlin turned to the last page of the inquiry letter, to the conclusion section.

There were blank lined sheets of paper there, reserved for the expert panel to write their defense conclusions.

The sound of ink seeping onto paper from a fountain pen could be clearly heard in the quiet conference room.

His characters are small, but every stroke is steady.

"After on-site technical review and verification, the electrophoretic deposition process and rare earth doping formula of the military electron tube project of the Third Electronic Components Factory have complete theoretical consistency and experimental verification support. No violation of basic physical laws was found. It is recommended to continue to implement it."

Signature, date.

He pushed the inquiry letter toward Ma Gong.

Ma Gong took the document, glanced at what Zhou Changlin had written, picked up his pen, and signed his name with a swift and decisive motion.

The inquiry letter slid down to Engineer Liu.

As Liu looked at the line of conclusion text, his lips pressed into a thin line.

Three seconds later, he picked up the pen and signed it.

The pen tip lingered on the paper a little longer than needed, but the signature was eventually completed.

Xu Chongwen stood up from the audience, his leather briefcase tucked under his arm.

He didn't look at anyone, and turned to walk towards the conference room door.

The sound of leather shoes stepping on the cement floor was rhythmic, neither too fast nor too slow, as if maintaining a certain dignity.

The door was opened and then closed.

The footsteps in the corridor gradually faded away.

Factory Director Zhang picked up the enamel mug and took a sip of cold water.

His Adam's apple bobbed as he swallowed.

After putting the jar down, he let out a long breath.

As Zhou Changlin stood up to tidy up the notebooks and letters on the table, he added a line of small print below the conclusion section of the signed inquiry letter.

"It is recommended to conduct an electron microscope analysis of the coating cross-section morphology to improve the process documentation."

He handed the letter back to Jiang Ming, and stopped as he passed by Jiang Ming.

"On page nineteen of your report, the water used for electrophoresis suspension is listed as triple-distilled water."

Zhou Changlin turned his head to look at Jiang Ming's profile, his voice low.

"But your derivation on the blackboard has very high requirements for sensitivity to interfacial impurities, and the ion residue in triple-distilled water may not be clean enough."

Jiang Ming neither denied it nor offered much explanation, only replying with one sentence.

"We have switched to ion-exchange water, and the report will be revised later."

Zhou Changlin nodded.

He didn't seem surprised by the answer, as if he had already guessed from the logical deduction that the water quality needed to be upgraded.

He turned back before stepping out the door, speaking casually as if he were talking about something neither big nor small.

"We have a Japanese-made electron microscope in the aerospace materials department. If you need the equipment for coating cross-sectional morphology analysis, I can help you coordinate it."

Wu Hanzhang, who was standing behind, paused for a moment when he heard this. His hand, which had been holding his reading glasses, was suspended in mid-air.

When Zhou Changlin arrived, he acted like a judge, but when he left, he took the initiative to help coordinate the equipment.

In less than an hour, their identities had been completely reversed.

Ma Gong walked slower than Zhou Changlin.

As he passed Jiang Ming, he slowed his pace and lowered his voice, saying, "Comrade Jiang Ming, I'm working on thermal barrier coatings for engine blades at the Institute of Aeronautical Materials. Perhaps we can learn from your approach to achieving uniformity in electrophoretic deposition."

He took a pencil and a folded piece of paper from the pocket of his Zhongshan suit and handed them over.

"If it's convenient, please write me a parameter summary, just the core variables such as concentration, electric field strength, and time."

Jiang Ming took the manuscript and nodded in agreement.

After Ma left, only the employees of the Third Electronics Factory remained in the meeting room.

Factory Director Zhang stood up from his chair, holding the enamel mug in his hand.

He walked up to Jiang Ming, opened his mouth as if he wanted to say something.

In the end, he simply patted Jiang Ming on the shoulder, but with considerable force.

"Go back to the workshop and keep an eye on your pipes."

Jiang Ming folded the signed inquiry letter and stuffed it into the left breast pocket of his work clothes, the edges of the paper being caught by the already frayed fabric.

He turned to leave, but Director Zhang called him back from behind.

"Wait a moment."

Factory Director Zhang took a folded telegram from his pocket and handed it to Jiang Ming.

When the thin paper is unfolded, there is only one line of lead type.

That was the format for confidential telegrams, and the sending address was the Northwest Base.

The text is so brief that it doesn't require a second reading.

"The delay line diagram has been received; assembly will begin tonight."

Jiang Ming's gaze lingered on that line of text for two seconds, then he folded the telegram, stuffed it into his right breast pocket, and placed it separately from the interrogation letter on either side.

In Workshop No. 1, five pipes are still running.

The microammeter pointer is stuck at 284.

In the Gobi Desert of Northwest China at night, Chen Zhiyuan was probably using a Soviet-made spare coaxial cable and an adjustable capacitor from a discarded transceiver to connect two unequal lengths of cable to the input of a mixer, following the formula on the back of the blueprint.

We'll assemble it tonight and test it tomorrow.