Contents

I. From Hanzhong to Shaanxi Normal University

II. My First Encounter with My Mentor

III. Knocking on the Door

IV. Joining Fang Group

V. The Lesson Learned at the Earthquake

VI. My Strict Mentor

VII. Body in Canada, Heart at SNNU

VIII. A New Journey at XJTU FIST

IX. Gratitude to My Mentor

Time is truly a wondrous thing; before I knew it, more than forty years of my life had passed. The ancients said, “At forty, one is free from confusion”, but now that I’ve actually reached this age, I find that many memories are growing increasingly hazy and are no longer as clear as they once were. Lately, I’ve taken great pleasure in reading reflective essays — such as Wen Yan Ji (Collection of Hearing the Geese) from Jilin University and Dan Yuan Chen Zhong (Fudan Campus Morning Bell) from Fudan University. I’ve savored every single piece, finding them deeply engaging. Perhaps it’s the passage of time, but these writings constantly urge me to look back on the path I’ve traveled. This year marks the 70th birthday of my esteemed mentor, Chinese Academy of Science Academician Fang Yu, which has further strengthened my resolve to record those memories in my own humble words. My writing may be simple, but when I actually sit down to write, I find myself at a loss for where to begin. So, let me take my thoughts back to that autumn of 2001.

I. From Hanzhong to Shaanxi Normal University

I was born in 1982 into an ordinary rural family in Hanzhong. The first eighteen years of my life were uneventful; I spent a fulfilling and happy time in Hanzhong. Back then, I didn’t have a very deep understanding of science—perhaps because I lived in a small town. During my junior high and high school years, I was deeply influenced by my grandfather. Born in 1928, he worked as an English teacher at a middle school after his name was cleared. One can easily imagine what a moving sight it must have been—a white-haired elderly man speaking English with reasonable fluency. Many years later, when I heard Teacher Fang explain why he had been admitted to Shaanxi Normal University, I suddenly felt an indescribable sense of resonance. It turned out that the reasons we both entered the same university were strikingly similar: we were both influenced by a relative who was dedicated to the field of education.

That fall in 2001, my parents accompanied me from Hanzhong to Xi’an. I still remember that night clearly; my parents, who rarely traveled far, seemed just as nervous and a little uneasy as I did. The train departed in the evening and arrived in Xi’an around seven in the morning. The three of us, dragging our heavy luggage, walked out of Xi’an Station. I vaguely recall that senior students from the university were there to meet us. We boarded the university’s shuttle bus for new students, still hauling our heavy luggage, and were taken to Shaanxi Normal University — now known as its Yanta Campus, a place locally referred to as “Wujiafen”. As soon as we stepped through the campus gate, the scene that met my eyes didn’t match the university I’d imagined. Shaanxi Normal University was indeed a beautiful, dignified, and rustic institution of higher learning, but that day, as we approached the entrance to the student dining hall, a light rain was falling, and the entrance was still under construction—it hadn’t been completed in time for the start of the semester. That muddy construction site instantly made me feel a stark disconnect from my expectations of college life. I thought to myself, “My college experience shouldn’t be like this; it should be just like what I’ve seen in TV shows and movies”. Fortunately, the dormitory the university assigned us was quite nice—probably the best on campus at the time — a four-person room with beds on top and desks below. After a brief introduction to my roommates, Hu Yunhe and Li Yingzhi, my first day at Shaanxi Normal University began.

After completing the enrollment procedures, the School of Chemistry and Materials Science at the time gathered the parents who had come to campus in a conference room on the second floor of Teaching Building 7 for a very special parent-teacher meeting. I did not attend; I learned all of this later from my parents’ accounts. According to their description, an academician gave them a very warm and approachable presentation. To be honest, my parents didn’t go into much detail, so I don’t know exactly what was said at the time. It wasn’t until about half a year after I started school that I learned that the academician was none other than our beloved Academician Gao Shiyang. Unfortunately, Academician Gao passed away during my sophomore year, and not having had the opportunity to hear his teachings in person remains one of the greatest regrets of my life. After all, he was the first academician I ever met, and he was also the first academician my parents had ever met.

The military training at the start of the semester gave me a unique perspective on this university. I remember that within two weeks of the semester beginning, the Student Dining Hall was already fully completed, so we were able to enjoy delicious meals during our breaks from training. To this day, I still believe that Shaanxi Normal University’s canteens rank among the best in the country, and the reputation that “Shaanxi Normal University is a food lover’s paradise” is well-deserved.

My college years flew by fast. I vaguely remember my first days in class, when a group of veteran professors — including Prof. Ma Biehou — taught in a thick Guan Zhong (Central Shaanxi) dialect. Most of my classmates couldn’t quite understand what the professors were saying, but we still felt that they were full of passion and completely dedicated to their work. Gradually, many of us began to learn the Guan Zhong dialect. My somewhat halting Guan Zhong dialect today was largely honed during that time. Nurtured by the bonds of friendship and the knowledge I gained, I quickly adapted to campus life. My close friends — Hong Bo, Yang Baolin, and others — and I loved exploring every corner of the campus to discover the university’s heritage, culture, and every nook and cranny: the library, the gymnasium, the movie theater, and the auditorium. We were also eager to get to know every faculty member. Strangely enough, even after nearly a year at the university, the few of us had never once discussed who the president was; we’d only caught a glimpse of him from afar at the opening ceremony. At the time, we simply took it for granted. On this beautiful stretch of land spanning over 700 mu (about 115 acres) at Wujiafen, I happily spent more than a year of my life.

II. My First Encounter with My Mentor

College life flew by. During my time at university, I was surrounded by close friends, and I also met Yan Ni, who has who has been my wife all these years. We thoroughly enjoyed our wonderful college days; back then, we would engage in lively discussions about our ideals, our future, and the things we hoped to accomplish. It was truly the age described by the verse: “In our youth, clad in fine clothes and riding spirited horses, we made the most of our prime years with purpose and wisdom”.

Youth is, for the most part, intertwined with alcohol. My close friends — Hong Bo, Yang Baolin, Li Zhaohu, Tian Wei, and others — and I would often get together; with just a bottle or two of beer and a plate of peanuts, we could chat away until late into the night. Whether by the sports field, in a restaurant after work, or in our dorm, we often made the most of our youth with poetry and wine. However, our favorite spot was Qujiang Liuyin, behind the Xuezhi Restaurant. There was a pond — neither too large nor too small — along with a few stone benches and some rockeries. Though modest in size, it was our favorite place to gather. At night, with just a few bottles of beer and a few plates of snacks, we’d chat about everything from amusing classroom anecdotes and newly acquired knowledge to our future and our individual aspirations.

Apart from occasions where we were very far away, such as the opening ceremony, I don’t have many memories of my beloved teacher, Prof. Fang Yu. I remember one late night in June 2003, around midnight, when the three of us — Hongbo, Baolin, and I — had just finished evening study hall. Each of us was holding a bottle of beer as we sat by the Qujiang Liuyin, sipping our drinks and savoring the moments of our youth. Suddenly, Hongbo raised his hand and pointed: “Look, there’s our president!”

That scene remains etched in my memory to this day. A tall, dashing gentleman, riding a bicycle with a briefcase clamped to the back, sped past us. The lights that night were exceptionally bright — thanks to the university, which never restricted electricity use; the campus was always brightly lit at night, perhaps partly because there were so many female students. Under the bright lights, Hongbo pointed to the professor and said, “That’s our president — the most distinguished scholar in the Chemistry Department, President Fang Yu”.

At the time, I wasn’t even quite sure who the president was; I only knew that the Chemistry Department had an exceptionally brilliant scientist. For the next half hour or so, our conversation revolved entirely around Prof. Fang, as we tried to piece together a complete picture of him using our own inaccurate and scattered bits of information. “A towering figure to look up to” — that was probably the only feeling we all shared at the time. The peach and the plum trees say nothing, yet paths form beneath them. It wasn’t until many years later that I truly understood: that figure riding away on a bicycle late that night was, in itself, a silent lesson in life.

Life is truly wonderful. Because of this little incident, I became extremely interested in Prof. Fang and was eager to find out what this principal and scientist — who didn’t return home until late at night — was actually doing. Of course, it may also be that as time passed and I grew older, having had the good fortune to listen to Prof. Fang’s lectures on numerous occasions, I formed a clear yet vague impression of him. But at that time, I hadn’t given it much thought — or rather, I didn’t realize what a stroke of luck it would be to have the opportunity to interact with President Fang up close.

III. Knocking on the Door

My college years flew by, and before I knew it, it was 2004 — the second semester of my junior year. Since I’d been a bit of a slacker during my college years and hadn’t qualified for direct admission to graduate school, a few of us friends began discussing our post-graduation plans and whether to apply for graduate school. When I graduated with my bachelor’s degree in 2005, as a graduate of Shaanxi Normal University, it wasn’t too difficult to find a job. My family also thought it would be best for me to find a stable teaching position at a middle school and live a quiet, uneventful life. But that summer, I suddenly realized I didn’t want to live my life following such a predictable path. So, with mutual encouragement from Yan Ni and a few friends, we decided to take the graduate entrance exam. I decided to apply to my own university, while Yan Ni applied to the Chinese Academy of Sciences. Information was relatively scarce back then, and I was so naive that I didn’t even think to contact a potential advisor in advance; I simply opened my textbooks and buried myself in studying.

In the winter of 2004, we took the master’s entrance exam. At the same time, we also applied for advisors for our undergraduate theses. I would be working on my undergraduate thesis in Prof. Gao Lingxiang’s research group, while Yan Ni would be working on hers in Prof. Li Baolin’s research group. At that time, I knew that some of my classmates had already joined Prof. Fang’s research group, and I couldn’t help but feel a bit envious.

Fast forward to the spring of 2005. As soon as the semester began, we received our graduate school entrance exam results. It was relatively easy to get into our own university, and I ranked first in the Materials Science program. Unfortunately, Yan Ni didn’t perform as well as she could have and missed her chance to enter the Chinese Academy of Sciences, but her determination remained undaunted, and she decided to take the exam again. By then, I had put my playful side aside and was devoting a great deal of time to my undergraduate thesis. The topic of my undergraduate thesis was related to barium carbonate nanofluids. I really enjoyed the feeling of conducting experiments and was very glad I had chosen to pursue graduate studies. Of course, this was largely thanks to Prof. Gao Lingxiang’s meticulous guidance. During that period, I met Prof. Gao Ziwei and his mentor, Prof. Wang Jiying; both had a profound influence on my future development. After the exam results were announced, the interviews followed immediately. At that time, we took the exam first and then selected an advisor — it was a mutual selection process between students and advisors. One day, while chatting casually with Prof. Gao Lingxiang, she said, “This is a mutual selection process; you can also explore other research areas and faculty members”. Perhaps because I had just learned that I had scored first place on the exam, I couldn’t help but wonder if I could visit other research groups. Coincidentally, some classmates were working on their undergraduate theses in Prof. Fang’s research group, and after hearing their brief introduction to the group, the idea took root in my mind.

Although I’ve been at Shaanxi Normal University for nearly four years, I didn’t know much about scientific research. Through a classmate, I learned that there was a senior student named Gao Lining in Prof. Fang’s research group, who handled many of the lab’s affairs. So I mustered up my courage and waited downstairs with Yan Ni for her. That day, I rather boldly stepped forward to introduce myself: I was a senior graduating this year, had just finished the second round of graduate school entrance exams, and wanted to ask if there was a chance to join Prof. Fang’s research group. I later learned that a considerable number of students apply to join Prof. Fang’s group every year. Miss Gao asked me how the exam had gone and what my past academic performance had been like. I didn’t have much confidence in my past academic performance, but regarding the postgraduate entrance exam results, I said with a touch of pride, “I did pretty well — I came in first.” Unexpectedly, her first remark left me feeling disheartened. She said, “In recent years, Prof. Fang has never accepted the top-ranked candidate”.

I was completely baffled: Why was that? Even so, I put my pride aside and asked my senior classmate to pass my message on to Prof. Fang. I thought to myself that it was definitely worth a try — perhaps this was one of the few good qualities I had in my life. Later, one day, Prof. Fang asked me and another student who had been accepted into his graduate program — Li Huihui, who later became my fellow student — to come to his office for a brief conversation. Strangely enough, to this day I only remember that this meeting ever took place, but I’ve completely forgotten what Prof. Fang said to me — I suppose I was just too nervous at the time. I only remember Prof. Fang telling me that he didn’t recruit the top-ranked student because he held an administrative position and couldn’t always admit the most outstanding students into his research group. But perhaps I was still a spirited young man back then, because Prof. Fang said he would give it some thought. I truly have no recollection of anything else — perhaps when people are extremely nervous, they experience this kind of selective amnesia.

After some time, Prof. Fang finally agreed to accept me as his graduate student. Once my plans were set, Yan Ni also decided to retake the graduate entrance exam, with the goal of joining Prof. Fang’s program as well. This wish was successfully fulfilled the following year. Upon learning that Prof. Fang had accepted me, I felt both incredibly nervous and immensely excited. At the same time, I felt deeply indebted to Prof. Gao Lingxiang and was sincerely grateful to her for giving me the opportunity to successfully complete my undergraduate thesis. During the summer of 2005, Shaanxi Normal University was organizing the IUPAC Satellite Conference on Physical Chemistry, and Prof. Gao Ziwei served as the conference secretary. Since I had performed reasonably well while working on my undergraduate thesis in Prof. Gao Lingxiang’s research group, Prof. Gao Ziwei asked me to serve as his secretary. It was precisely during those days of conference preparation that I truly had close contact with Prof. Fang. It could be said that it was from that time onward that I no longer felt so timid and shy when I saw Prof. Fang, and I was able to have brief exchanges with him.

At the time, I was just a recent college graduate, working my way through the most basic and menial tasks in the secretarial office. But I watched the senior female students in Prof. Fang’s research group as they bustled about at conferences, handling everything with ease — and I was filled with admiration. I, too, looked forward to the day when I could take on responsibilities at academic conferences just like them. That conference was a real eye-opener for me. I met Academician Tian Zhongqun and Prof. Ren Bin; many years later, I even reminisced about this experience with Prof. Ren. He was perhaps the first academic giant I had the privilege of meeting outside of university. I also met world-class academic luminaries; the one who left the deepest impression on me was Prof. Peter Atkins of the University of Oxford, author of the classic textbook Physical Chemistry. Watching Prof. Fang interact warmly with these world-class scholars deepened my admiration for him even further. At that conference, I also met Fang Xiaohua, who was still a high school student at the time. I was particularly envious of her ability to converse fluently in English with these foreign professors; it was only later that I learned she was Prof. Fang’s beloved daughter. I was assigned to accompany and guide these world-class scholars on a visit to the Terracotta Army Museum with her and several graduate students. Xiaohua handled the communication, while I took care of the administrative arrangements. The image of Xiaohua and me walking under the scorching sun, each carrying a large bag of drinking water, remains vivid in my memory to this day.

IV. Joining Fang Group

In August 2005, since I had been attending Shaanxi Normal University since my undergraduate years, I simply moved from one building to another and joined the lab ahead of schedule. It was only then that I gradually began to interact more closely with Prof. Fang. Because I had always held him in such high regard, I didn’t dare speak up. I couldn’t understand the various academic terms he used, nor did I grasp the scientific issues he discussed with the senior female students, and I had no idea how to design an experiment.

I remember one day when Prof. Fang called me into his office. As far as I can recall, the layout of Prof. Fang’s office has remained unchanged over the years: it consists of an inner and outer room, with the inner room serving as his office and the outer room as a small conference room. The conference table in the outer room has been there ever since I first set foot in Prof. Fang’s office, and it still stands today in his office at the Institute of New Concept Sensors and Molecular Materials at Shaanxi Normal University. Every time I sit there, I can’t help but feel a flood of emotions.

In that small conference room, Prof. Fang assigned me my first research project — one that would become a key concept I could hardly avoid for the rest of my life. He asked me to work on conjugated polymers. Just hearing the word “polymer” was enough to give me a headache, and with the addition of the completely unfamiliar term “conjugated”, I was truly nervous. Prof. Fang patiently explained everything to me for about an hour, describing what conjugated polymers were and teaching me how to search for relevant literature and how to analyze a research paper. This was, in all likelihood, my very first real lesson in scientific research.

Fortunately, Prof. Fang insisted on teaching the course on the principles of fluorescence himself at that time, which also gave me my very first English-language textbook: Prof. Lakowicz’s Principles of Fluorescence Spectroscopy. Because we were Prof. Fang’s students, senior labmate Miss Gao Lining distributed a copy of the English textbook to each of us. We accepted the book with great joy, only to realize upon opening it just how difficult it was to read. But precisely because Prof. Fang was teaching the course himself, we had to tackle this tough challenge head-on. At that time, our graduate class was small, usually only about ten students, but because Prof. Fang was teaching the course, the class swelled to as many as twenty or thirty students. Since I was Prof. Fang’s student, I was responsible for organizing the relevant materials and scheduling class times.

Prof. Fang’s classes were incredibly engaging. Although he distributed the textbook Principles of Fluorescence Spectroscopy, he used lecture notes he had written himself for every class and always began by writing on the blackboard. This had a profound impact on me; the blackboard filled with fundamental principles in English captivated us completely, and those are probably the most meticulous notes I’ve ever taken. The following year, I passed these notes on to my classmate Yan Ni, who was taking the course later on. By then, Prof. Fang had already become the president of Shaanxi Normal University, but as far as I know, he never missed a single class for this course. To master this subject, I figured out a little trick, which I’d like to share here — it’s something I often tell my own students as well. Once I entered the group, I realized that trying to grasp this material by plowing through the original English texts was clearly beyond my capabilities at the time — my English foundation was weak, and I lacked the perseverance to work my way through such a massive tome. So I obtained the master’s theses written by my senior classmates Gao Lining and Ding Liping. I placed Prof. Fang’s lecture notes and my seniors’ theses on my bedside table in the dorm, and every night when I returned to my room, I would pore over them carefully. Ever since I was a child, I’ve lived by the saying: “Read a book a hundred times, and its meaning will become clear”. It was precisely from that point on that I truly understood what research the lab was conducting, why we were doing it, and how to go about it.

Prior to this, my senior labmates — Gao Lining, Ding Liping, Lü Fengting, Zhang Shujuan, Kang Jianping, and Hu Jing — had all focused their research on polycyclic aromatic hydrocarbons, with pyrene being the most commonly used fluorescent group in the lab. The conjugated polymers I took on, however, were not only entirely new to me but also a field the entire lab had never explored before. With his exceptionally keen academic insight, Prof. Fang selected this research topic for me. From the principles and historical development of conjugated polymers to their application in explosive detection, and on to the preparation of thin films, there were countless questions for us to explore, learn, and understand.

At that time, due to his heavy administrative workload, Prof. Fang was almost never able to spend long periods in the lab during the day from Monday through Friday. He would only drop by occasionally at lunchtime, and every evening after work, he would come to the lab from the administration building — known among the university community as the “White House”. It wasn’t until many years later that I learned Prof. Fang had turned down countless invitations at the time, choosing instead to devote his limited free time entirely to the lab. During my college years, I was quite playful and restless; most afternoons were spent either playing sports or fooling around with friends. After joining the lab and witnessing Prof. Fang’s diligence and dedication — or perhaps simply to better myself — I resolved to break those bad habits. From then on, I made it a point not to return to my dorm at lunchtime; if I felt sleepy, I would simply rest my head on my desk for a quick nap. Every evening at six o’clock — or even earlier — I would go to dinner, and after eating, I would return to the lab as quickly as possible to continue my work. I never imagined that, many years later, Prof. Fang would repeatedly mention this habit of mine. I suppose it was just a small change I made, inspired by Prof. Fang’s example. Perhaps it was precisely these subtle changes that enabled me to persevere on my path in scientific research.

During that period, Prof. Fang was extremely busy. At the time, one of my senior labmates had gone abroad to pursue postdoctoral research, so I took on many of the lab’s administrative and general duties. Looking back now, these tasks may seem insignificant, but at the time, I felt I had truly come to regard the lab as my home. It’s easy to say, but I believe this is the most basic requirement I have for my current students.

The path of scientific research is not an easy one. In the field of conjugated polymers, Prof. Fang designated several research projects for me, including polysilane, polythiophene, and polystyrene-based polymers. At that time, I had absolutely no idea how to conduct anhydrous and anoxic experiments — or, more precisely, how to perform anhydrous and anoxic procedures in the strictest sense. Prof. Fang therefore invited Prof. Zhang Guofang, who had just returned from Germany, to provide me with hands-on guidance. To this day, I remain deeply grateful for Prof. Zhang’s help; it was he who helped me set up my first anhydrous and oxygen-free apparatus and taught me how to dry solvents. Today, students commonly use ultra-dry solvents, and research conditions are indeed a far cry from what they used to be.

However, I still took quite a few detours in my research and did not achieve the results I had hoped for. To give myself ample time, I participated in the integrated master’s-to-PhD defense in 2007, transitioning directly from my master’s program to a PhD program. During that defense, I met Tu Jianqing, who later became both a colleague and a close friend of mine at Xi’an Jiaotong University; his advisor was Prof. You Xilin. That same year, my classmate Li Huihui, under the guidance of Prof. Fang, successfully completed her master’s program and was offered the opportunity to pursue a PhD in Japan. People often say, “Comparison is the root of suffering”. While this statement is open to debate, that was certainly how I felt at the time. Witnessing a classmate go abroad for further studies — especially in those days — it would be hard to say that I was at peace; in fact, my heart was quite unsettled.

V. The Lesson Learned at the Earthquake

The year 2008 was destined to be an extraordinary one. Many major events took place that year — the worldwide celebration of the Beijing Olympics and the global financial crisis — but what left the deepest impression on me was still the Wenchuan Earthquake.

Since we were located in Xi’an, we were severely affected by the Wenchuan earthquake. At that time, I was in my second year of my PhD program and was considered one of the senior students in the research group. On the afternoon of May 12, 2008, Prof. Fang was still teaching a course on the principles of fluorescence to graduate students. The class was scheduled to take place in the conference room on the sixth floor of Building 7 at Shaanxi Normal University, beginning at 2:30 p.m. The sixth-floor conference room was the best-equipped meeting room in the university at the time, and many academic conferences were held there. Even so, Prof. Fang — who was always meticulous in his academic work — checked the conference room’s projector and still asked me to bring our research group’s projector, as it provided better quality. By then, Prof. Fang had already begun using PowerPoint presentations in conjunction with blackboard notes for his lectures. I always made Prof. Fang’s instructions my top priority. At 2:00 p.m., I carried the projector to the conference room, set it up and calibrated it quickly and skillfully, and then waited for Prof. Fang in the room. Watching the students take their seats one by one, I couldn’t help but recall my own days as a student attending his lectures. I later learned that my junior, Peng Haonan, was one of the students in the audience that day. I used to enjoy sitting in the back row of the classroom to listen to Prof. Fang’s lectures, but back then, he would always “mercilessly” shoo me out, telling me to return to the lab to work.

Prof. Fang had a habit of arriving at the classroom at least fifteen minutes early for every class. Around 2:20 that day, Prof. Fang entered the classroom and began talking with the students. After confirming that all the equipment was in order, I went downstairs to return to the lab in Building 6. On the way, I suddenly felt the world spinning. In fact, I didn’t immediately realize what was happening until someone shouted, “Earthquake!” At that moment, I had only one thought: I immediately rushed up the stairs and ran back to the conference room. When I reached the conference room, I saw Prof. Fang standing by the window, looking down to assess the situation outside. I shouted, “Earthquake!” Prof. Fang immediately yelled, “Have the students leave first! Don’t take the elevator!” Those words have stayed with me for the rest of my life. Knowing that Prof. Fang was in the habit of never being without his computer, I instinctively picked up his laptop, which was sitting on the desk. Prof. Fang organized the students to evacuate the room in an orderly manner, and he was the very last to leave. Our Building 7 was reportedly built with aid from the former Soviet Union and was already several decades old; the stairwell still featured an open-riser design. Prof. Fang and I walked side by side at the very back; the only sound on the entire staircase was the rustling of the students’ footsteps — no one spoke. Walking down the staircase felt like being on a violently rocking boat. I supported Prof. Fang, unsure of what the outcome would be. In just a minute or two, a thousand thoughts raced through my mind, but being with Prof. Fang gave me immense courage. Fortunately, the staircase withstood the test. I later learned that the earthquake had indeed caused immense devastation — not only in Wenchuan but also in Xi’an.

After going downstairs, Prof. Fang immediately rushed to the main administration building. I, on the other hand, stood there in a daze. What happened next left everyone feeling deeply shaken. Under the university’s unified command, the entire campus began an orderly recovery effort. Prof. Fang also arranged for a comprehensive safety inspection of the laboratory as soon as possible. That was the only instruction I received from him during those few days. I often wonder why I made that decision at the time. Perhaps it was due to Prof. Fang’s daily guidance through both words and actions, as well as the deep respect I felt for him from the bottom of my heart.

VI. My Strict Mentor

I had always assumed that since Prof. Fang was both the university president and a renowned scientist, he must have had few worries. It wasn’t until I heard him speak about it during a meal together that I realized there were many hardships behind the scenes. Prof. Fang had a habit of spending Saturdays and Sundays in the lab whenever he wasn’t away on business. At lunchtime, he would ask us to pick up a few simple dishes from a nearby restaurant or canteen, and he would pay out of his own pocket to treat us to a better meal. This was something we truly looked forward to back then — having lunch with Prof. Fang, especially when he treated us to a special meal. During meals, as Prof. Fang discussed science and occasionally shared anecdotes about the school’s development, I came to realize just how many hardships he had endured throughout the institution’s history. Reading about those stories in several articles Prof. Fang has written in recent years evoked a special sense of emotion in me — perhaps because I had heard him recount them firsthand during those shared meals.

Sometimes we don’t work hard enough. I recall seeing Prof. Fang lose his temper twice. One time involved our senior classmate Lü Fengting — now a researcher at the Institute of Chemistry, Chinese Academy of Sciences — who took us on a team-building outing, which was really just a group dinner, with the entire lab going out to have fun. Prof. Fang arrived at the lab to find it completely empty. He was furious and called us, but none of us dared to answer. Looking back now, it was truly foolish of us — that incident must have genuinely angered Prof. Fang. The next day at noon, after finishing work at the administration building, Prof. Fang summoned us to the conference room for a meeting. I had never seen Prof. Fang lose his temper like that before; I gritted my teeth as I endured his criticism, while Lü was already in tears. At the time, we didn’t fully understand, but now that I’ve become a teacher myself, I can truly appreciate Prof. Fang’s frustration at our lack of drive and her disappointment that we weren’t living up to our potential.

Although we all worked very hard afterward, our research did not go smoothly. I joined the research group in 2005, but by 2008, I still hadn’t published any papers. I remember one weekend at noon, Prof. Fang was editing my paper and asked if I had completed the experiments he had assigned the previous week. I made various excuses to avoid answering. When Prof. Fang asked about the third and fourth experiments and whether I had made up for them, and I replied “no” to both, there was a moment when I distinctly felt that Prof. Fang was about to raise his hand, as if he were about to discipline his own child. I was terrified at that moment. Life is just that absurd. At the time, I was using a bar phone. Perhaps because I’d spoken with Prof. Fang on the phone that morning, I didn’t dare go out for lunch. Prof. Fang worked until around 1:30 p.m. and wanted to take a short break; only then did I slip my phone into my pocket and prepare to go eat. But as if by some strange twist of fate, I accidentally pressed the redial button and called Prof. Fang. My phone was in my pocket, and I didn’t even notice it. When Prof. Fang didn’t hear me answer, he hung up and called back. I switched my phone to silent mode and didn’t pick up. Prof. Fang was probably worried that I was emotionally fragile and that something might have happened to me. Little did he know that at that very moment, I was just busy eating a big bowl of noodles — something that, looking back now, seems both ridiculous and shameful. After I’d finished eating and picked up my phone, I saw several missed calls from Prof. Fang. I hurried over to her office, where, naturally, I couldn’t avoid a stern scolding. At the time, it wasn’t just my immaturity — it was also the teacher’s deep concern for her students’ safety. Since then, I’ve rarely made Prof. Fang angry again; perhaps that’s a sign of my own growth.

Later, I became the senior-most graduate student in the lab. Several junior colleagues — including Du Haiying, Wang Hongyue, Peng Haonan, Zhang Holland, and Cui Hong — joined one after another, propelling the research group onto a faster track of development, and things proceeded more smoothly from then on. With Prof. Fang’s strong support, many of my junior colleagues went directly abroad to pursue their doctoral degrees. I remained in the lab, continuing to conduct basic research under Prof. Fang’s guidance, while also devoting considerable effort to the development of explosive detectors. In 2008, the lab moved from Building 7 to Building 6, and in 2011, from Building 6 to Zhizhi Building on Chang’an Campus; I played a leading role in both moves, helping to complete each relocation of the lab.

By 2011, many of my junior classmates and fellow students were studying abroad, and Yan Ni also went to Georgetown University in the United States in 2010 for a joint training program. Upon completing my PhD, perhaps because my performance had been satisfactory, I was very eager to stay on at the university. At that time, Prof. Xin Yunhong, who had collaborated with us for many years, offered me what now seems like a very good opportunity: a position at the university. When I excitedly shared this news with Prof. Fang and expressed my desire to remain in the lab or serve as a lecturer, Prof. Fang unexpectedly refused outright and even criticized Prof. Xin — something that still weighs heavily on my conscience to this day. Prof. Fang pointed me in a new direction: one must have higher aspirations in life and pursue postdoctoral research. This completely dashed my hopes of staying on as a lecturer. Seeing that my classmates, who had performed less well than I had — and given that I was the university president’s own student — still had opportunities to stay at the university, I couldn’t help but feel a sense of injustice. It is only now, many years later, that I fully understand Prof. Fang’s well-intentioned decision.

The process of applying for postdoctoral positions was quite challenging. After finally receiving several offers, I reported back to Prof. Fang, who also taught me a new word — since he required us to write to him in English every time. I remember that when I told him about the offers, his first words were, “Don’t be silly. Go to Canada.” That was the first time I’d ever heard the word “silly”. So I made the firm decision to go to Canada to pursue postdoctoral research.

Time flies. In June 2011, I faced my doctoral dissertation defense. Prof. Fang specially invited Academician Jiang Lei to serve as the chair of my defense committee, which left me both delighted and anxious. Having him preside over the defense was, of course, a recognition of my doctoral work, but it also brought immense pressure. As is well known, Prof. Jiang Lei is an extremely rigorous scientist. On the day of the defense, he posed several profound questions that were truly challenging to answer. Fortunately, I was quite familiar with my dissertation, and in the end, I managed to complete the defense without any major mishaps.

VII. Body in Canada, Heart at SNNU

After graduation, I took a short break to adjust before heading to Beijing to process my visa. Once the paperwork was complete, I returned to school and began another relocation of the lab — this time from Wujiafen to the Chang’an Campus of the university. After a hectic one or two months, we finally completed the entire relocation of the lab just as the new semester began. Every year on September 28, Prof. Fang would host a dinner with his students. The 2011 gathering was held in Dawangcun, which at the time was the liveliest agritourism spot in Shaanxi. The atmosphere that evening was exceptionally joyful; Prof. Fang shared many heartfelt thoughts with everyone and, naturally, offered me plenty of encouragement.

Early the next morning, I set off for Canada, dragging two large suitcases behind me. I left behind at Shaanxi Normal University several boxes — about three in total — filled with items I’d collected since my undergraduate days; though they weren’t valuable, they held countless memories. Back then, I still believed I would return to the university someday, so I solemnly entrusted these boxes to my younger classmates, thinking I’d be back in a year or two, or maybe two or three. My undergraduate classmate Li Zhaohu, along with several younger lab mates, came to see me off. And so, I set out on my journey to Canada. It was also the first time in my life that I had taken such a long flight.

I was doing my postdoc at the University of Alberta in Canada, located in Edmonton, in western Canada — a city international students jokingly call “Ai Tun” (literally the Edmonton Village). As it happened, my senior lab mate Peng Junxia was also doing her postdoc at the same university. She was set to finish her postdoc and return to China the very weekend I arrived. So, quite naturally, I “inherited” the valuable possessions she left behind — everything from her room to her pots, pans, and utensils — which allowed me to settle into my new life abroad with ease. My postdoc advisor is Eric Rivard, a young professor. After a brief conversation with me that lasted less than ten minutes, he wrote down the first chemical reaction I was to perform on the blackboard. Of course, anyone who has done lab work knows that such reactions are often difficult to get right on the first try.

My days in Canada were rather monotonous, yet very fulfilling. Back then, as I was starting over in a completely unfamiliar environment, I filled my time with experiments. I remember that they didn’t use PowerPoint for group meetings; everything was done entirely by writing on the board. This had its benefits — it forced you to have a thorough understanding of your own research. Drawing functional groups and sketching orbitals taught me a great deal. However, the drawbacks were also obvious: discussions weren’t always thorough, as many experimental details couldn’t be conveyed through hand-drawn diagrams alone. I was still accustomed to the PowerPoint presentation style common in China. Although everyone struggled to adjust at first, we eventually came to accept PowerPoint presentations. From then on, Eric Rivard’s lab set a precedent for using PowerPoint presentations.

I was quite fortunate in the lab to have a fellow student named Kang Le, who was also from Xi’an. After completing his bachelor’s degree at Purdue University, he came to Canada to pursue a master’s degree in Eric Rivard’s research group. Having lived abroad for many years and received his undergraduate education overseas, his English proficiency far surpassed mine. With his help, I learned how to operate the lab’s various instruments and equipment, as well as how to handle the procurement of chemicals. At that time, Eric Rivard’s group focused primarily on inorganic chemistry and did not use column chromatography for separation. My new research project focused on organometallic chemistry, which required numerous organic chemistry laboratory procedures. Since column chromatography was a fundamental technique in Prof. Fang’s group, I seamlessly brought that skill with me and taught it to my lab mates. In return, I learned authentic inorganic chemistry in their lab, including a range of skills such as rigorous anhydrous and oxygen-free procedures and the growth of long single crystals.

I often recall how many of my friendships in Canada were nurtured over cups of coffee. I’m not a coffee drinker myself, but thanks to my experiences in various settings back home, I deeply understand how crucial it is to seek help from others. So a cup of coffee costing two or three Canadian dollars became the best — and simplest — bridge for communication. Whether it was with several master’s and doctoral students in the lab or with friendly staff members at an analytical testing center similar to those back home, a cup of coffee often served as the starting point that allowed me to get timely help when I urgently needed data. Perhaps this is also a small example of how traditional Chinese culture has “seeped” into Canadian life.

While conducting postdoctoral research in Canada, I still made a point of reporting my progress to Prof. Fang at least once a month. I would prepare my PowerPoint presentation in advance, have my junior lab mates set up the video call, and once Prof. Fang joined the call, I would give him a brief update. The phrase Prof. Fang repeated most often to me back then was: “Keep it up. You must work hard, make a name for yourself, and serve your country in the future”. Fueled by that encouragement, I worked in Eric Rivard’s research group for two and a half years.

During this time, in October 2012, after two years of joint training in the United States, Yan Ni returned to Prof. Fang’s research group. In June 2013, she successfully defended her doctoral dissertation and subsequently joined me in Canada. At that time, Gao Lining, who was working at Chang’an University, had arrived in Canada a month before Yan Ni and was also conducting research as a visiting scholar at the University of Alberta. The three of us supported one another in Canada, and both our personal lives and work went very smoothly.

After that, I moved to Prof. Jillian Buriak’s lab to continue my postdoctoral research. On August 24, 2014, our little one, He Yanxi, joined our family. Although those days were tough, I look back on them with immense fondness now. To be honest, over the years I’ve always felt a sense of guilt toward Prof. Jillian Buriak. During that time, I devoted more of my energy to my family, which is why I have yet to publish a collaborative paper with her — a significant regret in my life. Although I did my utmost to host her when she visited China later on, I remain deeply grateful for the care she showed me and my family.

At the end of 2014, the application process for the National Talent Introduction Program for Young Scholars began. After numerous lengthy phone conversations and words of encouragement from Prof. Yin Yadong, I made up my mind to join the Frontier Institute of Science and Technology at Xi’an Jiaotong University (abbreviated as FIST) and apply for a National-Level Young Talent Program through the university. To be honest, I wasn’t very confident at the time. However, Prof. Fang provided me with tremendous support, both in preparing the application materials and in refining my research direction. After submitting the application, a long wait began. Since winters in Alberta, Canada, are extremely cold and Yan Ni also needed to return to China to look for a job, in November 2014, we had to make a difficult decision: Yan Ni would travel alone with our tiny daughter, He Yanxi — who had just turned 100 days old — on a long-haul flight lasting more than 20 hours back to Hanzhong, our hometown. Due to issues with my visa, I was unable to accompany them, and their journey was truly incredibly difficult.

I remember it was one night in December 2014 when I suddenly received an email notifying me that I had been selected to participate in the defense for the National Specially Appointed Experts Young Talent Program, scheduled for January 2015. At the time, I was both extremely nervous and unfamiliar with the format of defense presentations in China, so I hurriedly began preparing my PowerPoint presentation. Regrettably, during my nearly four-year postdoctoral fellowship, I had not returned to China even once, but now I was finally boarding a flight back home. As soon as I arrived, I went to Xi’an Jiaotong University for a brief meeting with the officials, then immediately headed to Shaanxi Normal University. Seeing Prof. Fang, I felt a deep sense of warmth. Prof. Fang arranged a very formal academic presentation for me. Looking back now, after I finished my presentation, Prof. Fang remained silent for several minutes — a scene that rarely occurred. In the end, I could tell that, since I had just returned to China, he was extremely reluctant to criticize me. Yet he still pointed out very tactfully — and his words remain as clear to me today as they were then: “He Gang, the quality of your PowerPoint presentations has declined”. I believe that excellence comes from diligence, while idleness leads to decline. Perhaps it was precisely because I lacked a good platform for professional development during those years in Canada, combined with my own poor English expression and lack of skill in formal academic presentations, that this ability gradually deteriorated.

After that, under Prof. Fang’s guidance and with the full support of my junior classmates, I managed to complete the revisions to my PowerPoint presentation, though it was a challenging process. Throughout this time, the faculty at Jiaotong University also provided me with a great deal of guidance. After my final trial lecture, a professor from Jiaotong University offered high praise, which gave me a significant boost of confidence. After successfully completing my defense in Beijing, I learned upon my return that I had been selected for the program. I was overjoyed and immediately shared the good news with Prof. Fang. I then returned to the University of Alberta in Canada to handle the necessary follow-up procedures and handover, before smoothly making my way back home. Yan Ni also successfully joined the School of Materials Science and Engineering at Chang’an University that same month.

Xi’an, I’m finally back.

VIII. A New Journey at XJTU FIST

These past eleven years feel like a separate, complete story of their own. Time seems to have flown by even faster during this period. I often tell my students that, in a person’s academic career, the doctoral advisor is perhaps the most important and far-reaching influence. Although I spent four years conducting postdoctoral research in Canada, the fundamental academic ideas and logic I adhere to were already formed during my doctoral studies. After establishing my own research group, I often reflected: How did Prof. Fang guide me in my research back then? During his tenure as university president, Prof. Fang worked extremely hard, devoting a great deal of time to administrative affairs and spending relatively little time in the lab. Yet, for some reason, I always felt that Prof. Fang’s approach to students and to academia was so warm and natural — and this has shaped the way I mentor my own students.

Of course, establishing my own research group came with its share of setbacks and frequent frustrations. Whenever I confided in Prof. Fang, he always offered unwavering support, often saying, “When you move to a new and better platform, you’re bound to encounter setbacks. What matters is the mindset with which you face them, the approach you take to conducting research, and the values by which you live your life”. Bolstered by this belief, I gradually built my own research group, and some of my students have since achieved notable results. I remember that when I first published my first paper as the sole corresponding author in Angew. Chem. Int. Ed., I immediately sent a message to Prof. Fang. He replied very quickly to offer his congratulations. This was also the greatest encouragement I received that spurred me to continue my research. I also often took my students to participate in some of Prof. Fang’s academic events. Even when faced with these young researchers — who were effectively his “grandstudents” — Prof. Fang continued to offer them tremendous encouragement.

Before I knew it, I’ve been at Xi’an Jiaotong University for nearly a decade. I deeply cherish one honor I’ve received — the title of “Xi’an Jiaotong University Outstanding Graduate Advisor”. I believe that while my modest academic achievements are undoubtedly due to the support, guidance, and help of my professors, the title of “Outstanding Graduate Advisor” is something I’ve earned bit by bit through learning from Prof. Fang.

Now that I’ve become a mentor myself, when faced with my students’ lack of understanding, their occasional slackness, and their complaints, I often think back to who I was back then. I recall the day Prof. Fang refused to let me stay at the university and insisted that I study abroad; I recall the look of frustration in his eyes as he reviewed my papers, as if he were disappointed in a student with great potential. Only now do I understand Prof. Fang’s well-intentioned concerns. How could he not have wanted to keep his students by his side? He simply had a longer-term perspective and knew exactly what we needed at each stage of our development — even if we didn’t understand it at the time and even harbored some resentment. Looking back now, every decision Prof. Fang made for me was the right one. It is only after becoming a teacher myself that I can truly appreciate the depth of his dedication.

In 2023, Ms. Liu Ying, then Party Secretary of the Frontier Institute of Science and Technology, and Prof. Shao Jinyou, the institute’s director, had a heart-to-heart conversation with me. They suggested that Prof. Fang be appointed to a dual appointment at Xi’an Jiaotong University. Upon hearing this, I felt an overwhelming surge of joy, followed immediately by a sense of regret — I couldn’t believe I hadn’t thought of such a wonderful opportunity myself.

After that, Liu Ying and Shao Jinyou paid numerous visits to Prof. Fang. I sincerely hoped that Prof. Fang would come to Xi’an Jiaotong University to serve as an adjunct professor and continue to guide us forward. During that time, Prof. Fang also exchanged views with Academician Jiang Zhuangde on multiple occasions at conferences; the mutual admiration between these two eminent scholars further strengthened Prof. Fang’s resolve to accept a dual appointment at XJTU. Shortly thereafter, Liu Ying and Shao Jinyou successively took up key positions in other administrative departments, but even with these changes in their roles, they remained committed to this matter and continued to facilitate its progress. Later, the weight of this important responsibility fell on the shoulders of new Party Secretary Zhao Weibin and Prof. Liu Feng, whom I regard as an older brother. With the care and support of XJTU President Wang Shuguo, Party Secretary Lu Jianjun, and later President Zhang Liqun, among other officials, the significant achievement of securing Prof. Fang’s dual appointment at Xi’an Jiaotong University was finally realized.

We were truly delighted. Soon after, the Institute of New Concept Sensors and Molecular Materials at Xi’an Jiaotong University was officially established. At the same time, together with the Institute of New Concept Sensors and Molecular Materials at Shaanxi Normal University, we jointly applied for and were successfully approved to establish the Shaanxi Provincial Key Laboratory of New Concept Sensors and Molecular Materials. And so, a new chapter in Prof. Fang’s part-time work at Xi’an Jiaotong University began.

As I write these words, the INCSMM at XJTU is also progressing steadily. I look forward to its completion this golden autumn, when we will be able to move into the new facility and, under Prof. Fang’s guidance, continue to move forward and reach even greater heights.

IX. Gratitude to My Mentor

Life is finite, but learning is boundless. My mentor has always been a guiding light, leading me forward. Academically, he taught me to be innovative and to pursue meaningful, significant work; in life, he taught me never to give up easily in the face of setbacks, to always remain steadfast in my convictions, and to forge ahead courageously. To this day, I continue to take inspiration from the words Prof. Fang taught me — the very words I once used in my PowerPoint defense: “Work diligently and be a person of integrity”. These words are simple and unadorned, yet perhaps there are no more fitting words to guide me on my path forward.

Nowadays, although I often meet with Prof. Fang, I still frequently recall the moment I first met him. More than twenty years have flown by in the blink of an eye, and even I feel a bit dazed by it all. Meeting Prof. Fang and studying under his guidance may well have been the turning point that changed my life. I remember during a year-end gathering with relatives and friends back home, my uncle asked me a question that felt like a soul-searching inquiry. He asked, “How did you, a child from an ordinary family in Hanzhong, become a professor at Xi’an Jiaotong University?” I think my answer came almost instinctively, without a moment’s hesitation: “Because I met Prof. Fang and became his student.”

I am filled with gratitude and appreciation — words cannot express it all. I do not know what words could possibly convey my deep respect for my mentor, nor what actions could repay the trust she has placed in me, nor what emotions or state of mind I should carry with me as I move forward. But I know one thing for certain: walking alongside Prof. Fang is the greatest blessing of my life.

The mountains are vast and majestic, the river flows broad and deep; my mentors noble character is as enduring as these towering peaks and flowing waters.

With Prof. Fang’s 70th birthday approaching, we, his students, have no way to repay him; all we can do is turn this gratitude into the motivation to move forward. My mentor often said, “Doing every ordinary task well is extraordinary; doing every simple task well is not simple”. These words have long been deeply ingrained in my mind. Now that I, too, have become a teacher with students of my own, I follow my mentor’s example by advising them that character comes before scholarship, and urging them to stay grounded and avoid seeking empty fame. I believe this is perhaps the best way to repay my mentor — by passing on, bit by bit, what he taught me. My mentor is a towering tree, and we are all leaves on its branches; no matter where we may drift, our roots remain deeply embedded in that fertile soil.

A thousand words and a million thoughts are distilled into these simplest words:

May our beloved teacher enjoy a long and healthy life, and may he remain as evergreen as the pine and cypress. May the flame in your heart forever illuminate the path ahead for generation after generation of students. We, too, will transform this flame into a spark within our own hearts, passing it on to illuminate the lives of even more young people.

Student He Gang

First draft written on June 18, 2026, at Guizhou Zunyi Executive Leadership Academy

Revised on June 30 at Xingqing Campus of Xi’an Jiaotong University

Final draft completed on July 23 at iHarbour of Xi’an Jiaotong University