Then Jin Yichang quickly wrote down a set of theoretical equations for Semenov's thermal spontaneous combustion on the blackboard, and said: "Because it is a graduate course, everyone will read the textbook by themselves, and the main content of the class will be taught, and I hope you will preview it in advance." Pen "Fun" Pavilion www.biquge.info"

He pointed to the projected model and the schematic diagram of the thermal equilibrium relationship with a laser pointer, and began to explain the set of equations he had just written on the blackboard.

Nikolai Nikolayevich Semyonov, for his great contribution to chemical kinetics, was awarded the Nobel Prize in Chemistry in 1956. Semenov's theory of chemical chain reaction amount, thermal explosion theory and gaseous mixture combustion theory have always been an important theoretical basis for safety science and fire protection engineering. According to Semenov's theoretical model of thermal spontaneous combustion, we see the phenomenon of thermal spontaneous combustion of gas mixtures in containers. ”

After Jin Yichang explained a bunch of equations on the blackboard, he stopped, looked at the students sitting below and listened to the lecture, and then said: "I want to know, now, the students' understanding of the theory of Semenov's thermal spontaneous combustion, is it the graduate student who speaks or the student who flies?" ”

He looked at everyone, stopped again, and after a while, he saw a graduate student raise his hand to speak, and he pointed to the student who raised his hand: "Please come and speak." ”

"The process of thermal spontaneous combustion is caused by a constant increase in temperature. For the process of thermal spontaneous combustion of a combustible mixture of fuel and air in a container, both ignition and combustion are carried out in a limited container. Therefore, a part of the heat released by the reaction is always lost to the medium outside the container. These are the two most critical factors of Semenov's theory of thermal spontaneous combustion: the rate of heat generation and the rate of heat dissipation. By differential derivation, the solution of Semenov's equation for the ignition temperature threshold can be obtained. ”

"Good." Jin Yichang said, made a gesture, motioned for the graduate student who was speaking to sit down, and continued: "From the students' answers to the questions, we can know that everyone has a good grasp of the thermal ignition mechanism described in the undergraduate combustion science, the Frank-Kamenetssky theory of spontaneous combustion and the theory of Semenov's thermal spontaneous combustion. However, are there any students who can explain Semenov's theory of thermal spontaneous combustion more thoroughly? ”

He looked at everyone, and no one seemed to raise their hands to answer, so he said: "Let me give you a hint, according to Semenov's theory, the ignition temperature is related not only to the nature of the combustible gas mixture, but also to all conditions in the process of system change. ”

When Jin Chen saw this scene, he didn't want the graduate students to look down on the students, and he didn't want to pick the head in his father's class. He tried his best to encourage Mu Tianyu to raise his hand to speak, deliberately pulling his right hand up, Jin Yichang saw the two of them muttering, and when he saw Mu Tianyu's hand being pulled up, he pointed and said, "The students who raised their hands in the back row, you can talk about it." ”

Mu Tianyu glared at Jin Chen, and stood up helplessly: "I thought of the chain ignition mechanism. The activation energy of ordinary molecules is very large, and at ordinary temperatures, it has little influence on the development of the chain, and the branching reaction rate and interrupted reaction rate of the chain have become the main factors affecting the development of the chain. ”

"Well, good, please continue."

"Since the interrupted reaction of the chain is a chemical reaction between atoms, its activation energy is very small, in fact it is independent of temperature; However, the branching reaction rate of the chain is different, because its activation energy is large, and the increase of temperature has an increasing influence on the branching reaction rate of the chain, which can promote the formation of activation centers. Thus, at low temperatures, the rate of the chain branch reaction is very slow, while the rate of chain interruption is very fast, so the reaction rate tends to a certain value with time, that is, the activation center does not automatically accumulate to accelerate the reaction. ”

"Very well, please take a seat." Jin Yichang was very happy that Mu Tianyu and they were still freshmen who could understand the graduate course, and he was completely relieved that Jin Chen was directly receiving special training from the Jiangcheng Plan here, and he also firmly believed that the Jiangcheng Plan would definitely achieve unprecedented results.

Jin Yichang carefully looked around at the students sitting below, and continued: "We have discussed the application of Semenov's thermal spontaneous combustion theory under different conditions, and when we consider different conditions, we can obtain the temperature threshold of ignition by solving Semenov's equation. ”

He continued: "Semenov's discovery of chain reactions marks a new stage in theoretical chemistry and chemical reaction kinetics. Semenov applied the chain reaction mechanism to the study of combustion and explosion processes, suggesting the connection and difference between combustion and explosion. He pointed out that combustion is a slow explosion, and an explosion is an intense burn. ”

He continued: "Just as Semenov's theory helps us to achieve a rigorous quantification of the chemical reaction between combustion and explosion, we can achieve precise control of the speed and direction of various chemical reactions on this basis, which is precisely the purpose and long-term task of our research on Semenov's theory of thermal spontaneous combustion." ”

At this point, the graduate students all turned their heads to look at the back, and they began to exchange heads: "The row of juniors in the back is really not bad. ”

"It turned out to be those people who were hungry, and they only complained that we didn't catch the opportunity."

"I've heard that some of them are only freshmen, so it's really unambiguous to be able to keep up with our classes."

"It's really the back waves of the Yangtze River pushing the front waves."

"Not so obliquely, right? We're dead on the beach, right? ”

"What do you say?"

"Students," Jin Yichang smiled, motioned for everyone to be quiet with his hand, and further extended his speech: "When we study Semenov's theory, we should also learn Semenov's method and optimize our own knowledge structure. ”

Train, learn, learn, train,......

Soon Mu Tianyu and Jin Chen's sophomore years were coming to an end, Su Bufan and several of their seniors were already graduate students, and the members of the Eagle still did not relax in the slightest, completing one new special training after another, and completing one new course after another.

Mu Canghai has basically recovered his physical condition after a year of rehabilitation exercises. When recuperating from illness, the work of the head of the Jiangcheng fire brigade has been concurrently held by the deputy head of the detachment. As soon as Mu Canghai resumed his work, he reported to the Provincial Fire Brigade and applied for himself to be the deputy head of the detachment, and officially promoted the acting head of the detachment to the head of the detachment.

Just when the head of the corps was in trouble, Yang Jianjun, through the Military Commission, directly transferred Mu Canghai to the Chinese Armed Police University as an instructor and was promoted to the rank of major general.