Source | Zeng Yongchun Science Network Blog
Edit | Academic Jun
One of my PhD students passed the PhD thesis defense yesterday with a score of 90 points, which is my 6th PhD student to graduate.
It's been a long time since I've written a blog post about students. As a doctoral supervisor for 10 years, I became more and more cautious, and I did not dare to easily expose students in my blog posts.
Maybe it's my maturity!
Or, even if it's my old age. Never matured, has aged.
But I couldn't help but want to write about this student because she had been with me for a long time. This girl, who transferred from the Faculty of Science to my group for master's and doctoral studies, has been with me since 2014 until yesterday. Although in these 7 years, I have been angry with her countless times to the point of wanting to leave her alone, but she shouted "teacher" and "teacher", continuing our teacher-student relationship.
The story between me and her goes like this. In 2014, she went to my group with a master's degree or ph.D.
At the time of my time, I was flourishing, the students were just right, the funds were sufficient, and I didn't blink an eye. At that time, my meltblown machine was also in its prime, and the state was very good.
This meltblown testing machine was built by a factory I found after returning from a visit to North Carolina State. It can be said that the research team of the Benmei family can occupy a place in meltblown research at home and abroad, and this meltblown machine has made great achievements.
Today, it is old and fading, but when this student joins the group, the machine is at its peak.
So I decided to make meltblown her PhD project. She hadn't officially started her PhD career yet, but I couldn't wait for her to get started with the work I wanted to do most:
Study the turbulence characteristics of meltblown gas fields.
The meltblown gas field plays a key role in meltblown technology as a power field for pulling molten polymers into micro and nanofibers.
This high-temperature, high-speed airflow field that reaches subsonic speeds has a special turbulence characteristic, which is formed by the complex geometry of the meltblown die (airflow nozzle). The meltblown die used in industry is a double-slot structure, two high-temperature high-speed jets collide, act and diffuse under the die, forming a complex turbulence field, its evolution, its development, its beginning and end, is what I have been thinking about exploring.
So she and I started working on a hotline anemometer for turbulence measurements. The hotline anemometer was from the Faculty of Science, and they lent it to me. I spent money on a temperature module and configured a 3D mobile platform.
Even more extravagant, in order to measure the high-temperature flow field, I bought a high-temperature probe from Denmark without blinking an eye, and it took a year to reach the laboratory.
My idea at that time was to systematically dedicate the turbulent characteristics of the meltblown gas field to the world for the first time, so that later studies would cite our experimental results, as experimental verification of simulation studies, or directly as a guide for die design, turbulence measurement research is very important.
I have no intention of writing this blog post as a popular science. Unexpectedly, the results were not published until last year, six years later. The story in the middle is the theme of this blog post.
In 2014, I went abroad to study. In fact, it was a visiting study, but the Foundation Committee did send me a certificate of "obtaining the qualification of studying abroad from the national public dispatch". So there was a scene of students sending their mentors to study abroad. Looking back at the circle of friends on August 11, 2014, he wrote with arrogance that "today, students have sent congratulatory messages to wish their tutors a happy study abroad!".
At that time, I already had four or five PhD students waiting to be fed, and I was able to let them go to study abroad, thinking that I would never find the courage to come back when I was old today.
That trip to Brisbane was only three months, and I returned to school refreshed after enjoying the Australian sunshine and tranquility in comfort during those three months. At this time, the student also wanted to study abroad (visit). Naturally, I can't object to it – tutors can go abroad, and students are more qualified to go. She soon applied for a visiting qualification from the National Scholarship Council and prepared to go to Imperial College London. However, her path abroad is far more tossed than others. For nearly two years, I watched her toss visas, even from IELTS.
During these times, our turbulence measurement studies are almost as slow as a turtle crawling. As a mentor, I dare not speak out. She was distracted, what could I do?
Finally the visa came down, and it had reached her bosan. I hurried to ask her to summarize the results of the turbulence measurement before boarding the plane and prepare to submit it.
We finalized the content of the submission, I even finished writing the Insert, and then the results, the framework, and the first draft of the Insert were stored in the folder with her name on it, lying quietly on my computer desktop until a few years later, when they reopened. This is a postscript.
This student went to Imperial For a year as a visiting student, and my request to her was not to leave the meltblown project. So she and her mentor at Imperial College repeatedly discussed and collided with the research direction of using instability theory to study the bending instability motion of meltblown fibers in the airflow field. In this way, her previous experimental research on turbulence measurement in the air flow field and the research on the theory of unstable bending motion of fibers to be completed later can just constitute a complete doctoral thesis on the basic research of meltblown technology, which is expected to be a very in-depth doctoral thesis.
She's been in the UK for a whole year, and I know she's working very hard, because to fully transition into mathematical physics is not something that the average engineering student would want to do. However, she completely abandoned the task I gave her to write a paper on turbulence measurement research and publish it.
Maybe I was afraid that I would urge her to write a thesis, and she would hardly contact me. I really sighed!
So I also gave up, thinking about waiting for her to return to China, she always has to send a thesis to graduate!
A year later, she finally returned to China, and by this time it was already her bo four. Another PhD student in the group with her has already given birth to a child to defend.
And she didn't seem to be in a hurry, and she ignored me and chased her to submit. She remains immersed in instability theory, building 12 systems of partial differential equations of the highest 4th order, plus 7 boundary conditions. The sheer amount of computation of these equations took me and her almost two years.
By this time, the graduation deadline was approaching, and she had not yet published a single thesis.
As a mentor, I was on the verge of a breakdown. I saw that her eyes were vicious and resentful. It was as if she was a "negative person" who had failed us in our original intentions.
I forgot what method I used to get her to put aside the messy calculations and start writing turbulence measurements as a paper submission. At this time, I opened the folder that had been lying on my computer for three years, and I was like a dead man. Maybe it was born, and she seemed destined to do things without tossing and turning.
After her and I worked day and night, three papers were finally published. During this period, I experienced incomprehensible tosses, including the editor's misplaced review opinions, and I did not want to elaborate on them here.
During this time, I repeatedly broke down, and sometimes communicated with her almost to the point of dropping the phone, and the strong she cried out "teacher" and finally came to the day when the thesis was completed. It is undeniable that although the paper that should have been published a few years ago has been delayed for a long time, this long period of time has made me and her understand meltblown more and more deeply, and the published papers have reached a level that we are both satisfied with.
These are all indescribable mix of sorrows and joys, and I feel sorry that a doctoral dissertation has done so that I do not record it.
This article only records the graduation of students and wishes such a strong and persistent girl a smooth and prosperous life and career in the future.
Article links:
https://blog.sciencenet.cn/blog-531950-1320424.html
Source of this article: Zeng Yongchun Science Network Blog
Author: Zeng Yongchun
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