Zhang Zhonghua: Pursuit of “quasi” characters throughout his life

When Zhang Zhonghua, an academician of the Chinese Academy of Engineering who is thin and inspiring, and the chief researcher of the Chinese Academy of Sciences, took the stage to receive the award from Vice Premier Wu Yi of the State Council, people reported long and enthusiastic applause.

Zhang Zhonghua and his team won the first prize of the National Science and Technology Progress Award for the “Leading of the Quantum Hall Resistance Reference” project, which is more than 10 times more accurate than the highest level in foreign countries! Perhaps ordinary people do not understand such a slogan of scientific and technological terminology, and do not understand the significance of it, but the scientists present are very clear: This means that our country’s electricity metering with independent intellectual property rights is at the top of the world, which is to promote our country. The progress of science and technology is extraordinary!

After the meeting, when many media wanted to interview Zhang Zhonghua, he discovered that he was gone. Zhang Zhonghua had already returned in a hurry and headed into the lab.

Time is too precious for him.

On May 17 of this year, when the reporter transferred to contact him, he had just returned from an international metrological academic conference. He has already launched a charge on another peak of metrology science, the Quantum Quality Benchmark.

In the laboratory of the China Institute of Metrology, Zhang Zhonghua, who is 69 years old and has a simple clothing and a clear face, looks ordinary and easy. But when he talked about metrology science, his eyes were immediately blasphemy and exudes the wisdom of a big scientist.

“Saddam hid in the ground, why could the US missiles be able to drill and hit him? The satellites were all commanded by GPS. The GPS positioning system was based on atomic clocks mounted on satellites, and the atomic clocks. It must rely on metrology science."

“The televisions and refrigerators that are commonly used in daily life are good or bad. They are measured by electrical instruments. All electrical instruments are not accurate, but also rely on metrology science.”

"Are the air polluted? The measurement will produce a lot of data. These data are not accurate? It must be traced back to the standard amount of metrology science."

"So, say metrology is to manage the sky, to manage the ground, and to control the air..." Zhang Zhonghua said humorously.

"China's measurement must be independent

In 1965, after graduating from the Graduate School of Electrical Engineering at Tsinghua University, Zhang Zhonghua was assigned to the China Institute of Metrology and began his long journey of metrology science.

Here, inadvertently, the former member of the International Metrological Committee Wang Daxuan gave him the “most important lesson” in his life. In the early years after the founding of the People's Republic of China, physical measures were taken as the source of measurement in the international community. Since there was no metrological standard in China at the time, Wang Dazhao had only to go to the former Soviet Union to verify measurement results. Because of fears of temperature and humidity changes and bumpy roads affecting the accuracy of the measurement results, Wang Dazhao held the quilt-wrapped equipment tightly in his arms, carefully holding a baby. Waiting for his destination, his arms could not reach. "Can you understand the taste?" Wang Dazhao asked him gently.

Zhang Zhonghua did not fall down tears. "China's metrology must be independent and not controlled by people!" He secretly vowed. This became the driving force behind his hard work.

Zhang Zhonghua worked tirelessly. In the 1970s, he served as the main researcher of the national "calculated capacitance benchmark", which proposed the "changing boundary perturbation method" and solved the calculation problem of electrode geometry error. Since then, China's AC impedance standard has been independently traced. Later, the results of this project won the first prize of scientific and technological achievements of the former National Bureau of Weights and Measures. During this period, Japan heard that China was studying the technology and offered to compare it with China.

Interestingly, when Zhang Zhonghua asked about the results of the Japanese experiment, Japanese scholars said "can't find it." But when Zhang Zhonghua and their results came out, the Japanese quickly said that their results "have been found." Finally, through the comparison, it is confirmed that the results of both parties are exactly the same.

"Actually, where they can't find results, they don't believe that China can do it." Zhang Zhonghua "dumb dumplings - quite a few."

Time flies.

2006 Turin International Conference, France. Zhang Zhonghua strongly announced that China has declared war on the "Quantum Quality Benchmark" for measuring problems worldwide! All eyes are focused on this thin Chinese scientist. Previously, the Americans have spent more than 30 years investing 30 million U.S. dollars; the British have spent 10 million pounds in research for nearly 30 years; and the French have spent 9 million euros in research for more than 20 years, but they have not yet achieved the required results.

Is China OK?

However, the achievements of Chinese metrology science are enough to make people no longer doubt the enormous energy contained in this thin body and no longer doubt the power of the Chinese.

From the moment of Zhang Zhonghua’s wishful thinking, more than 40 years have passed. China has become an oriental dragon attracting worldwide attention, and China’s measurement scientific research has also stood in the world of science.

Britain, France, Germany, Japan and other developed countries have thrown olive branches to Zhang Zhonghua. Some requested cooperation, others expressed that they should provide generous financial support, and some directly gave him personally generous conditions. Even the United States has also offered to jointly complete the topic of “establishing a quantum quality benchmark”—which was unthinkable in the past. “In the past, Americans simply ignored you!”

Zhang Zhonghua was not humble or scornful, but declined. He said with confidence: "China's metrology science should take the path of independence and independence. We have this strength and this ability!"

A "quasi" word, the pursuit of a lifetime

In Zhang Zhonghua's eyes, metrology science has been condensed into one word: accurate. A "quasi" word allowed him to pursue his life.

"Quasi" is constantly changing. International metrology used the physical standard as the measurement source from the 1960s, and today it has derived the quantum measurement standard with basic physical constants. The accuracy has already undergone an epoch-making leap.

But in each period, Zhang Zhonghua strives to keep up with the international advanced level in his field, even leading the international level. Conditions are not as good as others, and we can make up for it by redouble our efforts. Sometimes we can make hundreds of experiments for a single data. "His scholarship is very rigorous," was evaluated by a German metrology expert.

Once, in the Sino-German trade cooperation, the Germans sent a batch of silicon steel sheets, which had been assessed as unqualified by the country, to Tianjin Port. The technician refused to sign the bill after the delivery inspection found abnormality. German color Li Ning Ge Geology: How can you prove that our product is not qualified?

In fact, technicians have already sent samples to the Chinese Academy of Sciences for testing. When the inspection data given by Zhang Zhonghua was presented to the German representative, the other party was stunned – the measurement results are exactly the same as those of Germany in the country! "I didn't think of it, didn't think of it!" They had no choice but to compensate themselves.

"The development of measurement science is backward, it will be bullied!" Zhang Zhonghua repeatedly told his students, "The core of metrology science is on 'quasi', and 'quasi' must be rigorous."

His students have a deep understanding of this. “How do you mess with the table? This is like learning to do it!” On that day, in front of the reporter, Zhang Zhonghua criticized his disciple without mercy. “You must start from the little things to do learning, and the measurement is Science that is not sloppy at all!"

In fact, this "quasi" word has been integrated into his blood. His students noticed such a detail: Zhang Zhonghua likes to wear a white shirt. Interestingly, for decades, he always wore shirts for the first time in the winter and summer.

With rigorous studies and attitudes to life, this way, year after year, Zhang Zhonghua left a series of footprints on the journey to climb the peak of measurement:

In 1988, he measured the value of the international system of quantized Hall resistance and was formally adopted by the International Metrology Commission as one of the basis for determining the international recommended value. In 1992, he presided over the establishment of the “superconducting strong magnetic field standard” project. Through the appraisal, for the international advanced level of similar devices, the "suppression method" proposed in the research has solved the international problems; in 1993, he discovered and solved the main error sources that hindered the improvement of the accuracy of the quantized Hall resistance standard and made it. The international leader in superconducting current comparators; in 1994, internationally, he used the computational capacitance in our country to measure the quantified value of the international unit of Hall resistance—this amount was later in the latest round of international basic physical constants. He was formally adopted during the adjustment process and contributed to the determination of the exact numerical value of the basic physical constants. In 1995, he was elected as an academician of the Chinese Academy of Engineering. At the age of 55, he became one of the youngest academicians at that time.

"Run against time"

In 1980, at the International Metrological Conference held in Germany, when the German professor Feng Kelu first published the “Quantitative Hall Effect”, this major discovery caused a great stir. All the scientists in the world were excited and a British scientist jumped up on the spot and shouted: "It's an incredible thing. I'm going to run back and study it. We must be able to get results first."

Everyone knows that a new era of measurement has arrived. As the only Chinese expert who attended the meeting at the time, Zhang Zhonghua's heart was also excited and straightforward. He quickly left home. On the deck of the ship, in the face of the vast sea, Zhang Zhonghua stood in the wind and felt that China must seize a place in the international metrology and science and technology field. It must first establish a quantum measurement standard with independent intellectual property rights!

Returning to China, Zhang Zhonghua could not wait to report the major discoveries in this measurement field and the importance of establishing China's Quantum Hall Resistance Standards to relevant departments. However, at the time, China's metrology business was in vain and the national strength and metrology research capabilities did not yet have the conditions for the study of quantum standards. Until 7 years later, his "quantum resistance benchmark" was included in the experimental project.

Unfortunately, by 1992, due to funding and brain drain, etc., the study of "quantum resistance resistance" was forced to break. Zhang Zhonghua was in a hurry. From January 1, 1990, the International Metrology Commission formally adopted a quantized natural resistance standard for Hall resistors instead of the physical reference that has been used for decades. After two years have passed, when will China have its own benchmark?

"If you are not afraid of the late start, you are afraid of rushing!" Zhang Zhonghua's mind sparked a raging fire of science: "The stones of other mountains can attack jade!"

In 1993, he again came to Germany, where metrology technology was developed. There is only one purpose: to learn advanced experience and establish China's quantized electronic benchmark. In 3 years, he devoted himself wholeheartedly to learning and research. Countless rest days, the entire German Federal Institute of Physics and Technology, only one person focused on his presence. Tired and tired, he walked out of the experimental building and went to play with a group of laid-back deers on the lawn in front of the building to relax his tired body and mind. For a long time, even the guards at the German Experimentation Institute saw him admiring: "The Chinese did not rest and came to work again."

Occasionally, the German counterparts will also play nicely: “Zhang, are you racing against time?”

Fortunately, an opportunity came soon. Pan Biqing, an expert leader who has been working on the measurement front, took the post of the head of the China Metrology Academy of Sciences. He resolutely told Zhang Zhonghua: “The quantized resistance benchmark must be developed. There is no money. I use the president’s funds to support you!” After many efforts, it also won the funds of the World Bank’s Ministry of Finance and the Ministry of Science and Technology, and stopped the quantized Hall resistance benchmark project for many years.

It's a good thing. Just as Zhang Zhonghua devoted his energies to the study with a hundredfold enthusiasm, the unwitting guest of the illness wraps his body again - he was found to be suffering from severe kidney disease. Upon learning of this news, the leaders attached great importance to immediately sending Zhang Zhonghua to the hospital with the best medical conditions. The leadership repeatedly told the doctor: "This is a national expert. He must use the best medicine and cure his illness at any cost!"

At this time, Zhang Zhonghua, who was lying in bed, thought that he had already entered the key research stage. He anxiously burned fire, and meditated again and again in his heart: He must not delay the subject, and must rush to deliver results in front of other countries. A few days later, the body was still in recovery phase, and Zhang Zhonghua made a strong push into the laboratory.

"The world's first, really outstanding"

Autumn is a harvest season. The harvest time of Zhang Zhonghua and his team also arrived.

On September 13, 2004, the "quantized Hall resistance benchmark" project ushered in the identification of the moment. At this moment, it has been 24 years since he established his great wish to formulate China's own quantum standard. It has been 17 years since the project was established in China.

At the appraisal meeting, the atmosphere was warm. Zhang Zhonghua, an academician of the Academy of Engineering, like a respectful student, read out the research report of the research group in detail and waited for the long-awaited identification results.

It is exciting that experts agree that this achievement has achieved a quantum leap in the international quantum research field! First of all, it is the first time in the world that it has theoretically proved that the value of the quantized Hall resistor has nothing to do with the shape of the device, and has contributed to verifying the universality of the quantized Hall effect. Second, the self-developed quantized Hall device broke through the foreign technology blockade and provided the core device for the subject. In addition, the self-researched sorghum-to-superconductivity flow comparators have greatly exceeded the level of internationally equivalent devices. The data of this research result is reliable, and the accuracy is the first of its kind in the world (10-10 scale). It is worth mentioning that these three major innovations all have our own independent intellectual property rights!

“This achievement was achieved by more than ten years of hard work by the scientific research team headed by Academician Zhang Zhonghua of the China Institute of Metrology. The built-in quantized Hall resistance reference has been improved by more than one thousand times than the traditional standard resistance. The international leading level.” When the chairman of the appraisal committee issued the above evaluation, the audience’s warm applause lasted forever.

However, what confused Zhang Zhonghua was that the International Bureau of Weights and Measures had not responded yet.

As early as 2003, the International Bureau of Weights and Measures organized an international key comparison of 100Ω resistance values ​​that was replicated on the basis of the quantized Hall resistance standard, with participation from 12 countries. The Chinese team led by Zhang Zhonghua finished the experiment within the specified time and submitted experimental data. However, the International Bureau of Weights and Measures has not published the results of the comparison.

Until March 2005, the Electromagnetism Advisory Committee of the International Bureau of Measurements informed Zhang Zhonghua that he would go to Paris for a briefing. After returning from Paris, in June the International Bureau of Weights and Measures finally announced the results of the comparison to the world. The results show that the measurement results in China are closest to the average value and the uncertainty is the smallest! - This means that the world's data must be based on China!

Afterwards, the team members learned that in this comparison, China's test results are so good that it is far superior to the test data of 11 other countries – the uncertainty index is more than 10 times higher than the foreign benchmark! Officials at the International Bureau of Weights and Measures did not believe that this was really done by the Chinese themselves, so the date for publishing the results of the experiment was repeatedly postponed. Until they heard the report of the research group, they were very convinced.

It is said that Mr. Warrard, the director of the International Bureau of Weights and Measures, waved his hands and shouted: "Unbelievable! Incredible!"

For this reason, Cui Qi, a winner of the Nobel Prize in physics for Chinese students and a professor at Princeton University in the United States, sent a warm congratulatory letter and spoke highly of this scientific research achievement as “the best in the world and indeed outstanding”.

Zhang Zhonghua said with emotion, but said only one sentence: "On this day, I waited too long!"

"Measuring science is like the root of flowers"

Little-known is that Zhang Zhonghua almost passed away with metrology science. In 1957 he was admitted to Tsinghua University with honors. He first studied military secrecy, and later changed to a motor major because of "overseas relations."

"Understanding" the past, Zhang Zhonghua laughed. He has two brothers of the same mother, a dentist in Taiwan and a director in the California Highway Authority. All of them intentionally or unintentionally "implied" that Zhang Zhonghua could work in the local area, but Zhang Zhonghua declined neatly.

He even "kicked" to the point where he was not willing to go out to lecture. Some developed countries such as Japan gave him a high price of 6000 US dollars for lectures. He did not accept the invitation. He would rather stay in a Chinese lab, do research, or bring students.

“One flower alone is not spring, and thousands of springs are full of spring gardens.” The brain drain at the end of the 1980s gave him a deep sense of urgency. “I’m old and a lot of work depends on young scientists. Like Peking University, Tsinghua University, and Polytechnic University. Some of Gao Gaocai made a study to run in the United States. This is a sad one!" He took a dozen of his doctors on his own, and in his heart, taking one more can retain one more person.

Therefore, Zhang Zhonghua does not have the word "leisure" in his life - in order to not affect the quality of education, and to not delay scientific research, all of his so-called leisure time is spent in the laboratory.

His student Lan Jiang said: “I arrived at the laboratory at 7:00 in the morning and the teacher had arrived; I then changed to the laboratory at 6 o'clock in the morning and the teacher was still there; the third day - I was late...”

Lan Jiang also said: "The teacher often talks with us, and we should not be impetuous. We must not be too utilitarian. We must reassure ourselves to carry out research... Foreign technical talents will eventually return to the embrace of the motherland. This is unquestionable. After all, foreign countries Not your own home..."

Zhang Zhonghua used his own experience to educate students. "Measuring business is of great significance to safeguarding national technological sovereignty, the independence of scientific research, and national economic security and national defense construction. The country is strong and individuals have a future. The Chinese can be respected." ”

“Measuring scientific research is an obscure job. The flowers in the garden are beautiful and people can see it. Metrology science is like the root of flowers. People can't see it, but it’s crucial.”

"Give me another decade."

Zhang Zhonghua, who was nearly 70 years old, still works for more than a dozen hours a day. Even his students are self-described. His thin body seems to have infinite energy. In the morning, when the sky was just dawning, he took the metro through the awakening city and came to the quiet laboratory of the Chinese Academy of Metrology.

The leader of the AQSIQ was very worried about his body. He was placed on several occasions to rest in the sanatorium. He did not eventually go. Leaders are sad and angry: Are you so busy? Zhang Zhonghua only smiled apologetically.

He is really busy. For many years, he has served as the standing director of the China Measurement Testing Society, the chairman of the Editorial Committee of the Journal of Measurement, the vice director of the China Instrument and Control Society, and the chairman of the Editorial Committee of the Instrument and Instrument Journal. Just two years ago, he also participated in the compilation of the "Encyclopedia of Electromagnetic Measurements of Electromagnetic Coils" and "Electromagnetic Measurement and Instrumentation" series as an associate editor.

He also used to bring students to experiment with himself as an academician. He always said: "The basic knowledge of young scientists is not yet solid. I will teach them all my life..."

What makes him feel even more urgent is the "Quantum Quality Benchmark," which is a large mountain in front of scientists around the world. "The whole world is engaged in it. Are we not going to do it? If we don't do it, we must be subject to human beings and we must rely on people's breath. So we must Engage!"

“Very challenging!” Zhang Zhonghua said with excitement, straightening his waist. “Give me another 10 years!”

“I have to invest 17 million yuan in the early stage of the country. I have to afford such a large sum of money!” Zhang Zhonghua blinked at him with a small, smug smile. “For 10 years, I’ve tried to use 10 years to come up with results.”