Chapter 111: It's a school girl

　　 "Han Jiaying, why are you here?" Xu Qiu asked in confusion:
　　 "Also, how did you get in?"
　　 Microelectronics building has access control. The school girl has just joined Teacher Wei’s research group not long ago, and there is a high probability that they have never handled access control.
　　 "On the school bus I took, two people came to the microelectronics building, and I walked in behind them."
　　 "You can tell me in advance and I will open the door for you."
　　 "I sent you a WeChat message, but you didn't reply me." Han Jiaying pouted.
　　 Xu Qiu touched his pocket. It was empty. The phone should be on the A501.
　　 This is a bit embarrassing, he hurriedly changed the subject:
　　 "Most of those two people are also in the material department. Which floor did they go to?"
　　 "The third floor."
　　 "They should be the students of Teacher Zhang Jianwen. Zhang Jianwen and Teacher Wei returned to China at about the same time, so the laboratory was also arranged in Zhang Jiang."
After 　　 said, Xu Qiu continued to ask:
　　 "By the way, what are you doing here?"
　　 "I just want to come to learn experimental operations with my brother, Chen Wanqing, sister..." Han Jiaying said, the lower her voice became.
　　 Is it difficult? The school girl thinks that Chen Wanqing is not very reliable in teaching, so she ran over to hold her thighs?
　　 Xu Qiu was a little bit dumbfounded:
　　 "Zhang Jiang is mainly doing organic synthesis. It is very hard and dangerous. Are you sure you want to learn?"
　　 Han Jiaying nodded seriously.
　　 "Then just follow me. At this stage, you should listen more, watch more and less move. Don't touch anything in the laboratory without my permission."
"Ok."
　　 "However, I have only done synthesis recently. After this batch of products are synthesized, I don't know when the next batch will be."
　　 Xu Qiu showed her the four layers of gloves in his hand:
　　 "You wear lab coats and gloves first, don’t do experiments. You wear one layer of PE gloves and one layer of latex gloves. If you do experiments, it’s best to wear four layers like me."
　　……
　　 While experimenting, Xu Qiu introduced Han Jiaying the precautions for organic synthesis and various common sense in the synthesis laboratory.
　　 The school girl is still pretty good. He follows wherever he goes, and doesn't disturb the equipment in the laboratory.
　　 And she also took out an experiment notebook to record Xu Qiu's teaching content.
　　 It's just that once the experimental log is in the synthesis laboratory, there is no way to take it out.
　　 Finally, she thought of a way to take pictures of the contents recorded in the experiment log and save it with her mobile phone. It was quite smart.
　　 In accordance with the laboratory tradition, Xu Qiu invites her schoolgirls to dinner.
　　 location, of course it is the cafeteria.
　　 After the meal, he sent the school girl to the school bus, Xu Qiu returned to the laboratory to continue the experiment.
　　 The huge laboratory, once again only left him alone, is really a little empty.
　　……
　　 Xu Qiu stayed in Zhangjiang for another night.
　　The question is coming. The next day is Wednesday, and there are classes in the morning.
　　 I have no choice but to skip class.
　　 When both experiment and class are not available, I can only give up the latter.
　　 Xu Qiu apologized to Shen Cheng, the teacher of "Nanomaterials" in his heart.
　　 Before, he asked Tian Qing, Shen Cheng never called his name in class, and the exam was relatively simple.
　　 Although it is a closed book, as long as he memorizes the more than 200 pages of PPT he gave, it is not difficult to get a good grade.
　　 Tian Haru said that she took the A easily in this course.
　　 Xu Qiu's grade point is 3.5. Exam skills, especially the skills of memorizing PPT, are naturally full, so it is not very empty.
　　……
　　 After processing the polymerization products in the morning, return to Handan campus in the afternoon.
　　 My senior sister made an appointment for today’s gel chromatograph to test gel permeation chromatography GPC.
　　 The six batches of polymers synthesized recently will be tested.
　　 Xu Qiu came to Caiyi 216, weighed about 1 mg of each polymer material, put it into a 2 ml disposable centrifuge tube, and numbered it with a marker.
　　 Then, together with Chen Wanqing, took a disposable syringe, oil phase filter, and gloves, and went to the test site-Advanced Materials Building.
　　 The principle of gel permeation chromatography is very simple. In one sentence, it is that the time for different molecular weight polymers to pass through the column is different.
　　At the end of the chromatographic column, install a signal detector that can detect polymer molecules, record the signal intensity at different times, and get the molecular weight distribution of the polymer through conversion.
　　 There are three commonly used parameters, namely number average molecular weight, weight average molecular weight and polydispersity coefficient.
　　Number average molecular weight is the arithmetic average of molecular weight;
　　Weight average molecular weight is the weight-weighted average of molecular weight, which is not less than the number average molecular weight in value;
　　 The polydispersity coefficient is the ratio of the two, which is greater than or equal to 1.
　　 The closer the value is to 1, the more concentrated the molecular weight distribution.
　　 Take extreme cases for example, such as the case of pure small molecules, where all molecules have the same molecular weight, the number average molecular weight is equal to the weight average molecular weight, and the polydispersity coefficient is 1.
　　……
　　 The two came to the Advanced Materials Building and first found the teacher in charge of GPC equipment, registered the test information, and got the room key.
　　 As soon as he entered the laboratory, Xu Qiu saw an instrument in the center of the room, still humming, and a computer next to it, and there was still a seemingly odor of solvent in the house.
　　 "Is this the smell of tetrahydrofuran?" Xu Qiu asked uncertainly.
　　 Chen Wanqing sniffed and said, "Yes, it is tetrahydrofuran. It is the solvent of the sample and the eluent of the chromatogram, but the content is not high, so there should be no problem."
After 　　 finished speaking, she pointed to the working instrument in the center and said:
　　"This is a gel chromatograph. The smart one we bought in our department is relatively smart. You can pause at any time and add new samples at any time.
　　Because there will be a fixed loss every time the instrument is turned on, usually a batch of samples are collected and tested together. UU Reading www.uukanshu.com runs the machine once or twice a week, depending on the number of samples, one or two tests at a time.
　　We have to prepare samples here before we can test. "
　　 Prepare samples in a laboratory fume hood, use tetrahydrofuran as a solvent to dissolve each polymer material at a concentration of approximately 0.5-1 mg/ml.
　　 It is difficult for individual samples to dissolve. Chen Wanqing pressed the two ends of the centrifuge tube and shook the centrifuge tube up and down to dissolve it.
　　 Xu Qiu also learned to operate.
　　 About twenty minutes later, all the samples were dissolved.
　　 Then, they used a disposable syringe with a filter head to filter the solution into the special glass bottle provided by the laboratory here, and the sample preparation was completed.
　　 Chen Wanqing has been trained before, so there is no problem with the operation of the instrument, and the operation manual is carefully prepared next to the instrument.
　　 The two put the sample into the instrument, locked the door, and returned the key.
　　 I will come back the next day to process the data and clean up the samples left here.
　　……
　　 On the way back to Caiyi, Xu Qiu suddenly remembered what happened yesterday and asked:
　　 "How did Han Jiaying go to Zhang Jiang to find me yesterday? You are not bullying others, right?"
　　 "How is it possible, I just said that you are about to post a big article, and then she went to join you." Chen Wanqing said:
　　 "Although I have a good idea of ​​my teaching level, but she did not look back when she left, I still felt offended."
　　 "Really?" Xu Qiu didn't believe it.
　　 "Of course it was a joke," Chen Wanqing smiled:
　　 "I asked her to find you. I feel like she will get started faster if she learns from you."