He Jihuan: Using Math To Do Textile

In the beginning of 2015, Elsevier, the international scientific and technological publisher, released the "Most Cited Chinese Researchers in 2014", choosing 1651 most influential Chinese scholars in the world. He Jihuan, the distinguished professor in the National Engineering Laboratory for Modern Silk, was on both mathematics and computational mechanics lists, and ranked first in mathematics.

With a Master's degree in Mechanics and a Ph.D in hydromechanics,
He is now teaching in the College of Textile and Clothing Engineering of
Soochow University. When interviewed by *Chinese Science News*, he called
himself a "layman" of textile industry. The questions is, how could
such a "layman" enter the most cited list of scientists in
mathematics and computational mechanics?

**"Forerunner" in Textile Mathematics**

"The main research direction of our team is textile mathematics, which is trying to use mathematical research methods to solve key scientific problems in textile engineering." He said.

This might still be a little bit abstract, but you would be more familiar if you heard that the technology developed by him is used in manufacturing techniques of space suit, Mongolian yurt, etc., as it can ensure the internal temperature to stay constant and the external temperature to quickly adjust to the external temperature.

To achieve all these crafts sounds easy, but it must go deeper to Nano-level when doing, which requires fractal geometry, non-continuum mechanics and fractional calculus. Therefore, textile mathematics is a pure inter-discipline seldom touched by scholars at home and abroad. Hence, He can be well entitled as the "forerunner" in this field.

He achieved a lot from researches and explorations for many years, among which bubble electrospinning technique is his favorite work. The traditional craft of making nanofiber is electrospinning, namely, to use needle to drag the thread one by one, of which the production efficiency is quite low. "Bubble possesses the mathematical beauty itself, but it is always hard to be avoided in traditional textile engineering. So I fully consider the mathematical feature of bubble, namely, the small surface tension of bubble." He is excited when talking about his favorite research.

Through the test, He found that bubble electrospinning was feasible. A number of bubbles produced on the surface of the spinning solution can break at once and form many jet flows. With the exogenous process of electrostatic force and airflow, the jet flow can be further stretched to finish spinning, which extremely improve the production efficiency of nanofiber.

**Keep Students from Being "Employees"**

In the seminars for first-year postgraduates, students came to the classroom with notebooks and pens, waiting for the first class.

However, it seemed that He didn't want to introduce any theory. He directly asked students to design a spinning plan. This laboratory does best in bubble electrospinning, but the first task for these students is to seek for a new plan.

"In scientific research, I don't like to follow others, and I also encourage my students to go where no man has gone before, and the best is to create their own paths", said He.

Among these students, some came up with the idea of using airflow to spin, which was encouraged by He. Of course, it was not the end, he also encouraged students to verify the rationality of their plans. So the student found two electric hair driers to blow the bubble, using the simplest and the most direct way to verify the scientificity of the plan.

Moreover, He also has unique ideas. For example, he gives tests without correct answers, and the answers would be right once students write the process of thinking with correct logic; he puts a particular emphasis on following the research thought of the researcher when guiding students to read the literature.

He encourages students to challenge theories of authority and put forward their own ideas. "Since the existing knowledge and conclusions will limit the mind, students can make achievements in their interested fields after learning divergent thinking and innovative thoughts, rather than being my 'employees'." He says.

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**Industry-university-research Progress Together**

There are various problems in the industrialization process, and those who work in the laboratory can only meet "the tip of the iceberg". So, the question is how to make students get to more practical problems?

Last year, He established his own company, which made the bubble electrospinning enter into an industrialization path--using the bubble electrospinning technique to produce nanofiber, then turn it to nanofilm, which is used for filtrating tap water, so as to remove the impurity and retain the minerals.

But industrialization is not just "using electric hair drier to blow bubble"; believing theories in books solely might bring out the condition of "machine runs faultlessly in the laboratory, but may not work after five hours' operation in industrialization".

"The industrialization process can expose the problems in scientific research theory and technology. On the contrary, we have many new research topics which enable us to do better and go further in this field." He says his company now has become the second classroom and laboratory for the scientific research team, and the scientific research problems encountered in the production process are solved by the cooperation between students and teachers. Some students even go abroad for exchange and visit, with their new discoveries in the industrialization process.

Encouraged by the "little achievements", students are in the condition of "thinking all the time". He doesn't worry about that students get up late and don't go to laboratory, because even in midnight they would have heated discussions on certain scientific research inspirations through telephone.

In these right-or-wrong discussions, he says, "students always have surprising ideas which not only improve their abilities of practicing and problem solving, but also drive me progress together".

Currently, He devoted himself into the quantitative production of civil nano-products and the research and development of more nano-textile products. He wants to carry forward his beloved nano-mathematics when cultivating innovative talents and serving local economic development.