Chapter 76 Encountering a Problem
Xu Qingzhou returned to the dormitory with his schoolbag on his back. Xu Zhengyang and the others received a lot of club leaflets on their desks.
"It's lively." Xu Qingzhou clicked his tongue.
Xu Zhengyang was still browsing the club information on the flyer. When he saw Xu Qingzhou coming back, he asked: "Old Xu, do you really not want to join the club?"
Xu Qingzhou put down his schoolbag and shook his head: "No, even if I participate, I don't have time to go."
"I signed up for the hip-hop club and the guitar club." Xu Zhengyang chuckled and recommended to Xu Qingzhou, "Old Xu, why don't you come to the hip-hop club? Those girls are more energetic than the others."
"Didn't you say that you are tone-deaf?" Xu Qingzhou paid more attention to the guitar club this guy joined. He usually cried and howled in the shower, but few of them were in tune.
Xu Zhengyang rolled his eyes and retorted: "Can't a tone-deaf person have a heart to pursue his dreams?"
"This guy was actually fooled by the pretty director of the guitar club." Kong Xianbo revealed ruthlessly and sighed, "And Lao Zhai also signed up for the guitar club."
Zhai Ziqiang said with some embarrassment: "I just want to learn an instrument myself."
Xu Qingzhou didn't tease Zhai Ziqiang about wanting to learn a musical instrument. It was not easy for Zhai Ziqiang's family to provide someone from Peking University. Learning musical instruments was not realistic. He looked at Xu Zhengyang with a smile: "Old Xu, look at the beauty, Dong Shan won’t be jealous if she finds out?”
"Dong Shan is also in the hip-hop club." Xu Zhengyang shrugged.
Xu Qingzhou was a little surprised. He didn't expect Dong Shan to be interested in hip-hop, and he was a little worried about Xu Zhengyang. At least now it seems that a girl like Dong Shan has a warm heart. Although Xu Zhengyang looks romantic, she is just a mouth-sucker. The dog is a novice, I don’t know if I can hold it.
In the dormitory, everyone continued chatting for a while. Except for Xu Qingzhou, who did not plan to apply for anything, Kong Xianbo planned to apply for the student union, and Zhai Ziqiang not only applied for the guitar club, but also applied for the literary club.
At 12 o'clock in the evening, Xu Qingzhou took a shower and went to the study room with his computer.
Looking at Xu Qingzhou walking out, Kong Xianbo, who was lying on the bed, frowned slightly, stood up silently, got out of bed, and took out the textbook number 1.
"Lao Kong, what are you doing with a book at this late hour?" Xu Zhengyang was lying on the bed, looking at his phone and giggling.
"Study." Kong Xianbo replied in a muffled voice.
Hearing these two words, Zhai Ziqiang, who had already closed his eyes, suddenly lost sleep. He turned on his phone and looked through the blackboard pictures taken in today's class.
For three whole days, Xu Qingzhou was basically immersed in various complex data, as if he had regained the state when he was in charge of the experiment, maintaining a three-point and one-line life in the library, dormitory, and canteen.
However, even so, as of the evening of the second day, he had only completed the establishment of the second set of models. While considering the impact of magnetic field strength on critical current density, he added the variable temperature to optimize the model so that it Includes the effect of temperature on critical magnetic field strength.
The relationship between critical magnetic field strength $B_c$ and temperature $T$ is:
B_c(T)=B_0\cdot(1-T^2/T_c^2)Bc(T)=B0(1T2/Tc2).
Xu Qingzhou turned on the computer, entered Python, and substituted this temperature-dependent critical magnetic field intensity into the critical current density model.
Bc=B0*(1-(T/Tc)**2)#Calculate critical magnetic field strength
ifBc
raiseValueError(“Temperatureistoohighforsuperconductivity.”)
Jc=J0*(1-B/ Bc)**n
returnJc
After Xu Qingzhou entered the values, he suddenly found that several sets of data were abnormal.
(B, T, J0=1e10, B0=12, Tc=4, n=1)
The output value, n should be 2.
n is the rate at which the current density decreases with magnetic field strength, which means that there was a problem on the 10th test of sample No. 22. In the study room, in addition to Xu Qingzhou, there was another boy who was fighting hard. He looked at Xu Qingzhou with various data placed in front of him, as well as thick draft paper with dense calculations written on it.
The boy couldn't help but sigh, this great god came from nowhere.
He met this person in the study room for two consecutive days, and he seemed to be doing an extremely difficult calculation.
The boy took a deep breath, cheered up, and suddenly felt the desire to win.
You can't compete in studies, you can't lose if you stay up late in class!
At this end, Xu Qingzhou didn't notice the boy's strange gaze at all. He had already begun to screen various data in detail. First, he checked the model. If there was no problem with the model, he checked the data, time, and magnetic field strength.
The data after sample No. 22 , brought in, there are also a few problems.
Yes, if the current experiment continues, by the time of sample No. 80, all aspects of the data seem to be stabilizing and improving, but once it reaches sample No. 100, the value of n will become 0.
Niobium-titanium alloy is a material with zero resistance. However, no matter how exquisite and perfect the processing is, in terms of physics, there will be losses during the transmission of electric current.
When n is 0, the current loss from the positive pole to the negative pole is zero.
Another hour passed. Xu Qingzhou took a long breath and leaned back on his chair. He seemed to have reached a bottleneck.
If we can't find any problems from the data, then we only have the materials?
Rubbing his temples, Xu Qingzhou glanced at the time and found that it was already 3 o'clock in the middle of the night. The senior who stayed up late with him left at some point. He simply turned off the computer, took his things, and went back to the dormitory to sleep.
On Thursday morning, the senior class ended and Xu Qingzhou went straight to the laboratory.
"Junior brother, is there any progress?" Wang Wei asked as soon as they met.
After not seeing each other for three days, this senior brother Wang seemed to be a lot more haggard.
Wang Wei is indeed worried. Not only him, but Zhao Shengwen and Hong Yayu are also worried. Time waits for no one. According to rumors, Jinling University has built a model and has now begun testing.
"Not sure yet." Xu Qingzhou sat down directly in front of the office and said, "Brother Wang, I want to take a look at the internal organization chart of each sample first."
"Okay." Although Wang Wei was anxious, he still nodded slightly. He had been waiting for three days anyway, so he didn't care about such a short time.
The information in the computer is very complete.
Sample types include Nb-44Ti, Nb-46.5Ti, Nb-48Ti, Nb-50Ti, Nb-53Ti, Nb-55Ti. In addition to the structural diagram, there is also a corresponding sample preparation ingredient list.
In addition to the two main raw materials of niobium (Nb) and titanium (Ti), a small amount of trace elements such as hafnium (Hf) and zirconium (Zr) are also added.
Xu Qingzhou kept observing the structural diagrams of niobium-titanium alloy materials, and at the same time called up the sample preparation ingredient list to confirm his guess.
Near 11 o'clock, Xu Qingzhou looked at Wang Wei who was sorting out data across the way and said, "I found the problem."
(End of chapter)