The next morning, Li Kangping sent a letter to Einstein and went to the laboratory.

After more than a month of processing, self-made parts and outfits, the equipment for the electron diffraction experiment of the Woodgate team is finally complete.

Next came the installation, and according to the drawings, we needed to install the whole unit with extreme care that was 5 inches high and 2 inches long.

The main operation of the installation work can only be undertaken by one person, and the other three people are assisted.

The main installation operation is carried out by Professor Woodgate and Li Kangping in turn, and the electrons will be ejected from the electronic emitter, which consists of an electron gun, a filament and a special glass instrument. Scattered electrons are collected with a double-layer electron collector and sent to a galvanometer for measurement. The inner and outer layers of the collector are insulated with quartz, and the reverse voltage is added to prevent electrons that have undergone inelastic collisions from entering the collector.

The sample is cut from a single crystal nickel grown in a crystal, ground and corroded, and the (111) side is facing the electron beam, because nickel is a face-centered crystal, and the (111) side is the most dense lattice of this type of crystal. The crystal is mounted on an axis in the direction of the incident beam and can be azimushed at will.

In the evening, Li Kangping said: "Professor, it will take about ten to twelve hours to complete the installation, and we will stay up all night until the early morning of tomorrow?" ”

"Oh, I'm sorry, it's my daughter's birthday and I have to go home now." Professor Woodgate said, "Go back and have some rest or have some fun, tomorrow we will work more than ten hours." ”

After some men succeed, they will know more and cherish life more.

When doing the space quantization experiment, Professor Woodgate made the laboratory his home and was busy experimenting day and night.

After returning from Brussels, Professor Woodgate spent more time with his family and enjoyed life.

This is the normal condition of man, so the people dispersed and went back to their homes.

Li Kangping returned to his apartment on Chenbian Street when the phone rang. Li Kangping answered the phone: "Hello." ”

"Is that Mr. Li?" It was a man who spoke.

"Yes, it's me."

"Kangping, I'm Rao Yutai." Men switch to Chinese mode.

"Brother Yutai, don't come unharmed?"

"I'd like to meet you before I get on the ship tomorrow in New York, can I?"

"Brother Yutai is leaving? We'll talk about it tomorrow after we meet. ”

Li Kangping learned that Brother Yutai had received a PhD from Princeton University and that Brother Yutai was about to return to China.

The next day, in the Woodgate Laboratory, thanks to the efforts of everyone, the delicate electron diffraction device was sealed in a glass bubble, followed by repeated baking and degassing, so that the vacuum level reached 10^-8 Torr.

"She's so beautiful!" Professor Woodgate exclaimed.

"Yes, she is the prettiest and most delicate girl I have ever met." Li Kangping admired this masterpiece.

"After a night of baking and degassing, it is expected that tomorrow morning, the vacuum level will be able to reach 10 to the minus 8th power. Vigil is hard work, but someone has to keep vigil, Mark, you keep vigil, can you do it? The professor gave instructions.

"I think I can do it."

So Mark kept a vigil, and the other three departed.

Li Kangping walked to the apartment on Chenbian Street, and he saw a person standing at the door of the apartment, this person was thin, wearing a dark suit, with two large boxes next to him, and he was spitting out smoke and smoking cheap cigarettes.

"Brother Yutai!" Li Kangping hurried to meet him, and he asked, "When will Brother Yutai board the ship?" ”

Brother Yutai said: "I will board the ship to Amsterdam at noon tomorrow, then to Germany, and then return to China via the Trans-Siberian Railway. ”

"Let's go upstairs first." Li Kangping helped pick up the box and led Brother Yutai upstairs into the room.

"Brother Yutai left suddenly, and the route back to China is so tortuous and long, why?" Li Kangping asked.

"The Deutsche Mark is depreciated, so I want to go to Germany."

It turned out that Brother Yu Tai had been invited by President Zhang Boling, and Brother Yu Tai would be the head of the Department of Physics of Nankai University after returning to China.

First there is Nankai Middle School, and then there is Nankai University. Nankai Middle School has developed into a well-known high-quality middle school at home and abroad, Nankai University is in its infancy, and the Department of Physics of Nankai University is currently just a name, with no professors, no lecturers, no students, no equipment, and no books.

Germany is the center of global physics, and Frankfurt am Main, Germany, is the book city of Europe and the world.

It coincided with the sharp depreciation of the Deutsche mark, and the Deutsche mark, which could buy a coat in the morning, could only buy a loaf of bread in the evening.

The dollar is strong, so Brother Yutai took the dollar cash and wanted to buy books in Germany.

From an academic point of view, there are many and complete physical literature in Germany, and there are many rare books that can only be found in Germany.

From the point of view of the cost of buying books, it is extremely cost-effective to buy books in Germany during the depreciation of the Deutsche Mark. What used to cost a few German books can now be bought in two large boxes.

Li Kangping was not happy, and even a little sad.

Brother Yu Tai is the head of the Department of Physics at Nankai University, but after Brother Yu Tai returned to China, he was unable to do scientific research in the short term.

That can only teach students, and teaching students must have professional books, so Brother Yutai took the way of ant moving, tossing from the Americas to Europe and then to Tianjin, relying on two large boxes to bring back the literature and books needed in the early days of the establishment of the Department of Physics of Nankai University.

Although there are many difficulties, Brother Yutai is full of fighting spirit, he said: "Nankai physics has nothing for the time being, and Chinese physics is also a barren land, I am willing to be the pioneer cow and try to reclaim a few acres of land." ”

Li Kangping said with emotion and sincerity: "Although Brother Yutai instructs Kangping in the future, Kangping is willing to work for Brother Yutai, Nankai Physics, and China Physics within the scope of his ability." ”

"Kangping, I have read "Matter Wave", but my brother is dull and it is difficult to fully comprehend "Matter Wave". Have you ever carried out your electron diffraction experiment? ”

"The unit is still being commissioned and it is expected to produce results within this year."

"So the best, so the best."

Chinese students who go to the United States to study physics are basically experimental physics.

Before Mr. Zhenning and Mr. Zhengdao achieved their studies, there were no theoretical physicists in the true sense of the word in China.

As an experimental physicist, Brother Yutai naturally yearns for high-end experiments that touch the cutting-edge ideas of physics.

The academic environment is not only about spending money to build laboratories and buying advanced equipment, but also about talent echelon and humanistic care.

"If the electron diffraction experiment is successful, Kangping will inevitably go to the next level. So Kangping, when are you going to return to China? Brother Yutai asked.

Li Kangping said: "If I get a PhD, I plan to stay in the United States for a few more years, and I may also go to Europe for further study. ”

"Whether it's good, or good, on the day Kangping returns to China, I hope that China can usher in a stable situation." Brother Yutai said expectantly.

The two chatted in the apartment for a while, and then went to the Retiro Hotel, where Li Kangping hosted a banquet to entertain Brother Yutai and see him off.