Li Kangping borrowed a bunch of literature and returned to his apartment on Chenbian Street to study it carefully.

On November 26, 1907, Russian physicist and inventor Boris Lvovich Rosing published an article in Scientific American about television.

In the scheme, the scanning of the camera part is a mechanical system, which is scanned by two rotating drums to complete the line and field scanning of the image respectively, and at the same time, the line and field synchronization pulses are also transmitted, and the photocell completes the pixel-current conversion. The video signal is transmitted to a Braun tube, which uses two separate sets of magnetic field deflection coils, and the scanning current is generated by electromagnetic induction.

Luo Xing's TV thesis is a design concept, after several years of hard work, continuous improvement, finally made the "TV" object, in 1908 obtained a British patent, 1909 German patent, 1911 American patent.

The word "television" is in quotation marks because Luo Xing's television is not a modern television set, and his television device can only transmit images of simple geometric figures.

Luo Xing is considered to be the "pioneer of television", and the "father of modern television" is someone else.

After brushing the paper, Li Kangping began to draw.

There are two main differences between Li Kangping's circuit diagram and Luo Xing's TV system circuit diagram.

First, Luo Xing's television system is a video signal transmitted by wired closed circuit, while Li Kangping's television system is a radio frequency signal transmitted by wireless open circuit.

Second, Luo Xing's TV system uses electromechanical scanning in the camera part, and electromagnetic scanning in the imaging part. And Li Kangping's TV system uses electromagnetic scanning entirely.

Li Kangping titled the paper "All-Electronic Television System".

In this article, Li Kangping invented a new academic term---kinescope.

Translated into Chinese, kinescope means "picture tube".

What exactly is a picture tube?

Li Kangping explained that the "CRT" should be an enhanced version of the Braun tube.

What is the enhanced Braun tube?

It takes time to research and make a physical object.

In Li Kangping's memory, the "all-electronic TV system" took more than ten years and cost $50 million from the basic theory to product research and development, and then to commercial operation.

Li Kangping can take fewer detours, but no matter how he takes shortcuts, he needs at least an elite R&D team of more than 100 people and R&D funds of no less than 5 million US dollars.

"All-electronic TV system" is not only the research and development of TV sets, but also involves the development, construction, operation and maintenance of TV station systems. It's not just a single product, it's a new telecommunications system.

In 1922, there was no television station in the world. Therefore, the "all-electronic television system" is a systematic project with a huge amount of work, and it is by no means something that Li Kangping can handle alone.

This did not prevent Li Kangping from writing a basic theoretical thesis on the "all-electronic television system" first.

Scientific American was fond of this type of paper, and Li Kangping finished writing "All Electronic Television System" and sent it to the editorial office of Scientific American.

The weather is getting hotter and hotter, and Li Kangping's master's graduation defense is scheduled for summer, as is the doctoral graduation defense.

The Hertley Building conference room is where several physics professors from Columbia University sit.

Professor Green and Professor Harris are acquaintances of Li Kangping, and these two professors attended Li Kangping's master's graduation defense last year.

Professor Woodgate's relationship with Li Kangping goes beyond acquaintances. is also a teacher and a friend, mutual benefit and win-win, the two are probably such a relationship.

Professor Savi and Professor Beckman, these two professors are not strangers to Li Kangping, they all eat together in Columbia University, and they have a certain understanding of each other.

Professor Green, who is still the leader of the defense team, spoke first: "We have not forgotten that this time last year, on that very hot day, we sat here and participated in the defense meeting of Mr. Li's "Silver Atomic Beam Method Verification Space Quantization Experiment". I am glad to see that this paper has become a classic paper in physics, and it has been presented at the Solvay Conference and recognized by physicists all over the world. ”

"Today, a year later, I am still presiding over Mr. Li's doctoral graduation defense, and I would like to ask Mr. Li to begin your presentation on the doctoral dissertation "Experiments on Nickel Crystals Being Diffracted by Electrons."

The necessary procedures were carried out in the necessary environment, and Li Kangping said in a loud voice: "Dear professor, I am K.P. Lee, a doctoral student and laboratory assistant in the Woodgate laboratory. Next, I will present the "Experiment of Electron Diffraction of Nickel Crystals". ”

"The purpose of the experiment of electron diffraction of nickel crystals is to prove the theory of matter waves, and I mentioned the electron diffraction experiment at the end of the paper "Waves of matter", so "Experiments on the Electron Diffraction of Nickel Crystals" can be regarded as a companion article to "Waves of matter."

"Please bear with my verbosity, I repeat the formula λ=h/mv because I think it's too important, it's the core."

"The design principle of the experiment of electron diffraction of nickel crystals is not so difficult to understand, simply put, it is to use electrons with known velocity to hit the nickel crystal, scatter the electrons to the electron collector, capture the electron diffraction pattern through the celluloid diaphragm, and obtain a series of curves after mathematical processing, and then compare them with the theoretical prediction value of "Matter Wave".

"Gentlemen, please look at the graph in the copy of the paper, the arrows pointing to the theoretical values representing the diffraction at all levels. During the experimental operation, the accelerating voltage increases, the electronic wavelength becomes shorter, and the measured values gradually approach the theoretical values......"

"Considering the internal potential of nickel, the measured data we obtained are basically in good agreement with the theoretical prediction of the Matter Wave. Yes, we did, we proved the correctness of the theory of matter waves. That's my statement, thank you. ”

Li Kangping calmly finished his thesis statement and waited for the professors' questions.

"From the experimental data, they are credible and informative." Professor Savi was the first to speak, who said: "As you know, many physics experiments fail at the operational level. I went to the Woodgate lab the other day and saw this experimental setup with my own eyes, and it was an extremely delicate device, and it was a remarkable thing to design, build, and install this experimental device, to make it work properly, and to collect data. ”

"Personally, I think that the phenomenon observed by electron diffraction experiments in nickel crystals is electron diffraction, not X-ray diffraction from high-speed electron collisions. In fact, the maximum acceleration voltage you set is 72 volts, which means that you are doing electron diffraction experiments in a relatively low energy environment. So what happens in a high-energy environment--- for example, at an accelerating voltage of several thousand or tens of thousands of volts? Professor Savi asked with interest.

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(Thank you for the 10,000 yuan reward of the hall master, I wish the hall master eternal youth and lasting strength!) ）