 He's a professor and a faculty dean of School of Rehabilitation. He received his PhD in 2004 from School of Rehabilitation Science in Beijing University. He worked as a research fellow in Poco University of Austria from 2004 and five, and then joined the University after that. His research interests involved a lot of economics in anthropology and urban anthropology. Good morning, everybody. Welcome to Beijing, and welcome to my university for this conference. At least, I'm quick for analysis. I have a background of ecology by training. In recent years I've been interested in the metabolism research, but I'm always confused about the metaphor. From the biology of ecology to the research in our domain, this is my outline about the U.S. concept of metabolism and also what we have achieved during several decades of research from 1965 to be domestic. And also how we can continue to do in the future from the metaphor for recent domain. It's a basic idea about the biology, the perspective of metabolism, and metabolism means change. Something change, happen, reaction, to make something alive. These two points are very important because for the safety, we need some of the reaction, and also we need something that makes the safety, you know, alive, too. So, as I find this, etymology in their Greeks, the words, remember, means change. And the notation for metabolism there refers to the process of changes that capture the system alive. And he had a very central initial use in ecology and the biophysical sciences. This is the very development roadmap that we are all familiar with in this process. But the first one is that it can be traced back to the last quote in 1860, 1852. But this is a very important point. Because during this state, there was a lot of debate and argument. Can this concept be expanded across the field? But the same thing, we have no more discussion or more debate. Can this concept be used in this area? We all think this is okay. It's good concept. And what we have to try to do is to find the method, find the model of modeling and measuring what's happening inside. There was no longer debate on the concept, the rightness of the concept. But during this stage, during this stage, when you look at the reference in that time, there are lots of argument debates about can this concept be appropriately used in macro level. Then, now, I don't want to talk about this, but we think things back to what we have learned from biology. Actually, in biology, maybe in ecology, there are lots of the key words. The first key word is based on the ecology, structure, function, equilibrium, and diversity. So all of these words, if you look at all of that, every mathematical, it's not that it can be widely used in our domain, every mathematical. And in biological domain, you will find another one. Anabolism. Cathabolism. And these words are also certainly used in our research on GRD. That's what you call it. Maybe we had all the chemical present by which food and these derivatives that broke it down. We have new building blocks, the energy. This segment of metabolism is a term, the catalytism. The same thing to separate and decomposition. And all the chemical present by which living cell and tissues are produced, the built up, will possibly from DNA to a large macro structure of biology and ecology. This anabolism, actually, is the build up new molecules by geophysics. These two preferences is very important for most of the biological present. And the follow-up on area, we have actually from our beginning to try to measure how much material and energy flows into the city and how much waste flow out of the city at the beginning. And then try to do the inside, trying the more detail of the material and energy flow inside. We have summarized some of the research here. The box, actually, North Korea is just, to my understanding, is a line and a box. The box means the stock. The line means flow. They try to depict or try to detail, no matter from the outside and the inside of the system. And we use the box to, the plus sign means the element, how much element. And the sigma means the cementation. You'll find that at the beginning of mouth of the inventory, through the wall of the construction material, there's no cementation, just the inventory. And then they try to be, to account more systematically from the material, the weight or energy, the jewels. They try to sum up some of those. And then with the development method, like the energy, we try to unify all of the, provide unify the coming out of the material. This is the one dimension. We use the single element, try to depict more detail of the inside and outside of the system. So use the network analysis to find the stock flow and how they dynamically and statistically modeling of the system and also the dynamic system. So roughly, it can be three times the research works. Firstly, the linear process. You just to measure how much we needed it and how much we emission to the environment. So results and environment pressure, you really can be, can be, can be predicted by this. And secondly, maybe our mind likes things, how much potential results we can mine from the urban metabolism. And finally, you try to network to know, try to understand the complexity of our system in the perspective of material flow analysis. I try to find the three types of thinking. Just thinking some basic ideas. As I said, no empirical analysis, but just thinking. So for, this is the building of construction area. You will find this is the material flow. This is stock. And this is the flow again. This is the flow. From this dimension, you will find the structure. That would be something, structure. If the structure can be, can be pre-function, we need additional flow. Different types of flow, like the energy, water to support the building who works properly. So I divide these two types, homogenous flow and heterogeneous flow to make this understanding of the stock and flow. You will try to do talk a lot of the decoupling. We think the building decoupled, but actually this decoupled process is coupled by another flow. The heterogeneous flow is replaced by a heterogeneous flow to create a function. This is what I get away from the ecology, because most of the ecology is structure and function. All of the structure and function needed something that could not be without. So if you try to imagine a flow like a molecule like this, there was a, yes, there was a decoupled from the homogenous flow with the stock. But sometimes the heterogeneous flow would be increased correspondingly. Second thing I want to think about. What is the affecting factor by the urban, like Beijing or Tianjin or Shanghai? What is the metabolism rate related to urban shapes, urban types, GDP or whatever? What do you think this? We can find two very famous rules in biology ecology. First is the elementary. I think we have some idea of this. Another one is the Alex rule, Alex rule, Alex rule. All of these things is to depict the affecting factor of the body, on the body's process. That's the, you know, perhaps the weight, the body, the body size, and the, sorry. No, no, this is not the right figure. Actually, this is a body size with a metabolic rate. So there are some of the linear or logistic relationships that are sometimes different. So like this one. Overall, a metabolic rate in the animal is generally accepted to show that activity, along with a scale from mass to the true power of the seven zero point seven five, knowing that the people are slow. And this is one of, but not all, there actually will be more to provide. Is this rule applies to urban scale or urban system? I'm not sure. We need to work to support or to deny or to approve of these rules in a study. Another one is a reminder. It is the resource, the resource we can recover from that currently. We actually call it, in a quality, we obviously material cycle and energy flow do not miss the material cycle, material cycle. Energy only can be flowed. Energy could not cycle. But the material cycle is driven by energy. There's no cycle without energy. So for the urban industry, if you want to mix the circular economy or to remind whatever you want, you need to the cost of energy. Very large cost. And also maybe a trade-off, a trade-off between energy and material. Sometimes you have to sacrifice energy to get back to resources. Sometimes you have to sacrifice your resources to get energy, whatever you want. So we need to be clear minded in the basic idea, the basic philosophy behind the ecology, material cycle and energy flow. This is actually three things that I'm currently working on. And also, one of my priorities to take this as the best work is where it changes. But we try to want to finish this. What's the next step? I have no idea. I'm not sure. But we try to find some of the basic idea of the beyond what we have already done, the current data, everyone, that's going down. Yes, actually lots more. We learn from the biology we call it. It likes the lexical biology. And also about the shelf of the law of tolerance. For the city, we should have a right resource for we to make the city to run properly, not on the threshold of uproofs or loads. So we need to find which one is the city's limiting factor. From the perspective of resource or in the law, whatever. See, and also the law of laxation in the mass of the law. And through all of it, even the equilibrium, diversity, the principle of the ecology can be to find their parallel or common partner in the area of metabolism. Okay. This is the final comment, Mark. The urban metabolism effort greatly promotes the knowledge and understanding of the methods of material material on the extent of in nature, especially not the possible six decades. We still need to go beyond the current paradigm to refresh the reach of biological and ecological knowledge to perceive the metaphor to a real sense of domain of the metabolism. Okay. Thank you. Thank you.