No abstract

The thermal protective clothing for high-temperature operation usually consists of three-layer fabrics and a gap called the air layer or Layer IV between Layer III and skin. In order to design more effective thermal protective clothing at less cost, based on the heat transfer principles, we establish heat transfer models of fabrics and air layer, which are one-dimensional nonlinear partial differential equations with constant coefficients. In the three-layer fabrics, we consider the effects of heat conduction and heat radiation in Layer I but only consider heat conduction in Layer II and Layer III. Furthermore, the heat transfer model of Layer IV is decoupled and simplified to steady-state heat conduction in Layer IV and radiation heat transfer on surface of Layer IV. According to the explicit difference schemes for the models, we use the parameters in an experiment which puts a thermal manikin in high-temperature environment for some time and measures the temperature of lateral skin at regular time, to solve the models and calculate the temperature of each layer. With MATLAB, the visual interface of three-dimensional temperature distribution is provided, which is reference for functional design of thermal protective clothing. We also compare the simulation result of skin surface with the experimental data. The results show that at the same position, the temperature rises over time but with decreasing rate and finally reaches the steady state. Moreover, at one moment after reaching the steady state, the temperature has a gradual decrease with the increase of distance from the external environment.

Nowadays, most land use projects disregard the impact of their decisions on the biosphere. However, they often directly affect the biodiversity and lead to environmental degradation. Considering this issue, we first select indexes from four dimensions: provisioning, regulating, supporting and culture, and establish a static ecosystem services valuation (SESV) model using equivalent factor method. Then, introducing dynamic adjustment coefficient and current discount rate, we construct a dynamic ecosystem services valuation (DESV) model, which is used to put a value on the environmental cost of land use projects. Moreover, we use entropy method to calculate the weights of the economic benefit indexes we choose and establish an economic benefit (EB) model to determine project benefit. After that, we select Canglong District Development Project in Wuhan and Three Gorges Project in China as a small community-based project and a large national project respectively to perform a cost benefit analysis using the models. As the results, compared to small-scale project, large-scale project can greatly increase the economic benefit, but at the same time, it notably increases the environmental degradation cost. Effectiveness analysis proves that the results are effective and reliable.