Chapter 494: Gradually feeling the joy of finance

Xu Qingzhou put the manuscript to one side; the battery experiment matter was not urgent. He planned to finish Song Yao's high-frequency signal synthesis first.

With constant in-depth understanding, he vaguely could understand Song Yao's joy.

Just like that saying: use a fulcrum, and you can pry the earth.

Find the right economic law, and you can make a huge commercial empire fall into paralysis, very fulfilling.

During the day in the library, he had already finished most of the content.

But he found that Fourier transform had limitations. If Tesla's price fluctuation cycle suddenly changed, like 10 seconds -> 5 seconds, Fourier transform couldn't capture the dynamics, and limited sampling would lead to spectral leakage.

To be more perfect, need to use the next step of wavelet analysis to strengthen.

Through the time-frequency localization ability of Morlet wavelet or Daubechies wavelet, can accurately capture the time point and intensity of such events.

To be figurative, it's like using scissors to cut a piece of infinitely long ocean wave recording tape. Limited sampling is like violently cutting the ocean wave recording, destroying the natural continuity of the signal, causing the pure "wave crest" in the frequency domain to be polluted by messy "sea spray". And the role of the window function is like using gradient scissors to gently cut the recording, making the start and end points transition smoothly, reducing noise.

Ding~

Just when the two were busy with their own things, the phone on Xu Qingzhou's desk rang.

Glanced at the name, he answered, greeted with a smile: "Professor Gu, good morning."

"Professor Xu, didn't disturb you, did I?" Professor Gu Zhizhong asked with a smile on the other side.

"Look at what you're saying, your call, how could there be no time to answer."

"Heard you kid are doing experiments on superconducting thin films?"

For Professor Gu Zhizhong knowing his research direction, Xu Qingzhou wasn't very surprised, still that saying, those doing academics are all in one circle.

Especially old professors like Gu Zhizhong who have peaches and plums all over the world, it's very easy to want to know something.

He nodded and said: "Yes, want to do substrate-free NbSn thin films based on ALD and graphene substrate."

"Tsk tsk, you are still the same as before, the things you do are always unexpected."

Gu Zhizhong sighed, paused, and said: "Looking at you, you won't want to do theoretical mathematics after returning to the country, right?"

"Still you understand me, can't sit still."

Xu Qingzhou said with a smile.

The superconducting thin film experiment has already started; if it can't be done this year, can only bring the project back to the country.

As for the future...

Energy.

Xu Qingzhou's research direction will lean toward this direction, and at the same time, can also synchronize the experiments in quantum mechanics once done.

"This is also quite good... however, you can also consider what specific research to engage in. Half a year, not short, not long, consider it in advance, laboratory equipment, venue, location, these all need time to arrange."

Hearing this, Xu Qingzhou immediately understood, smiling: "You old man are informing me."

"Hehe, the school is having a meeting, indeed someone mentioned about your return. I discussed with Old Chu, tell you first. Public is public, private is private, the requirements you should raise should still be raised."

"Okay, thank you and Professor Chu for the reminder, I will consider it."

October 10th, the breath of autumn is getting stronger.

After 3 hours of electrochemical stripping, lasting a month and a half, the first sample finally appeared in front of his eyes. Next, Xu Qingzhou spent another 7 days reserving shared equipment to complete characterization testing.

On the office desk was a test report from the shared laboratory.

【Sample Number: Nb3Sn_ALD_Graphene_001】

【Structural characterization results

Transmission Electron Microscopy (TEM) analysis

Grain size distribution:

Average: 85nm

Range: 30–200nm (Standard deviation ±40nm)

Grain boundary width: 3–8nm (micro-cracks exist in some areas, width ≈2nm).】

【X-ray Diffraction (XRD)

Main peak position:

(200) crystal plane: 2θ=32.5° (Intensity ≈1500cps, FWHM=0.3°).

(210) crystal plane: 2θ=46.8° (Intensity ≈800cps).

Impurity phase detection:

SnO peak: 2θ=26.5° (Intensity ≈120cps, proportion ≈3.5%).】

Xu Qingzhou and Carson were looking through the data in front of them.

Sun Simin and Ma Ersi were both resting their chins on their hands, looking uninterested; the sample situation was not satisfying.

Xu Qingzhou was very relaxed, jokingly saying to Sun Simin and Ma Ersi: "Cheer up, at the very least, we have reached the laboratory level."

From the current data, the sample performance was roughly the same as the finished product of James's team four years ago.

And it was even more different from the ideal performance pursued by major laboratories today. Figuratively speaking, this was equivalent to the performance gap between the antique machine equipped with Snapdragon 845 in 2018 and the 3nm photonic quantum SoC concept machine in 2025.

Sun Simin nodded, took a deep breath, "Although very disappointed, it feels very magical, participating in the production of a superconducting thin film with my own hands."

"Wake up, we are just doing odd jobs."

Ma Ersi added on the side.

After getting familiar, Sun Simin was not as restrained as before, pouted and retorted: "Be confident, doing odd jobs is also an experiment."

"We used a month to finish the achievements of Professor James and the others for two years."

Carson had a strong mentality, flipping through the report: "However... this grain size... a bit complex, from 30 to 200 nanometers? Very much like putting kindergarten kids and NBA players in the same locker room..."

"There are many places that need optimization and improvement. The next part is the key."

Xu Qingzhou tapped his fingertips and arranged tasks: "Carson, next Monday, you continue the experiment, use Sn(Net) to replace Sn(CH), combined with in-situ H plasma reduction, target to reduce SnO content from 3.5% to..."