多层孔隙材料在建筑施工中的隔热机理及其优化设计

基于热桥理论基本原理,本文采用理论分析与试验研究相结合的方法,研究建筑用孔隙隔热保温体系的热工能力挥发机理与优化方法,分析了隔热体系设计层数(n)对其热工交换系数和温度函数的影响,建立了相同厚度下n与保温体系热交换率的关系。再通过试验对比,确定了玻璃棉保温体系的最优层数。研究发现,随着n的增加,保温体系热工能力逐渐提升,但增幅逐渐降低,当n增加至4层时,保温体系热工效率最高,可达17.8%,试验结果与理论分析吻合。因此本文针对建筑钢屋盖隔热保温体系的优化方法可靠,且具有工程推广与应用价值。

Synthesis of Multi-component Mass-exchange Networks

This paper presents a superstructure-based formulation for the synthesis of mass-exchange networks (MENs) considering multiple components. The superstructure is simplified by directly using the mass separation agents (MSA) from their sources, and therefore the automatic synthesis of the multi-component system involved in the MENs can be achieved without choosing a 'key-component' either for the whole process or the mass exchangers. A mathematical model is proposed to carry out the optimization process. The concentrations, flow rates, matches and unit operation displayed in the obtained network constitute the exact representation of the mass exchange process in terms of all species in the system. An example is used to illustrate and demonstrate the application of the proposed method.

Development of an Emulator for the Plasma Process Control

This work aims at developing an automatic system for the control of the APS （air plasma spraying） plasma process in which some instability phenomena are present. APS is a versatile technique to produce coatings of powder material at high deposition rates. Using this technique, powder particles are injected into a plasma jet, where they are melted and accelerated towards a substrate. The coating microstructures and properties depend strongly on the characteristics of the plasma jet, which can be controlled by the adjustment of the process parameters. However, the imeractions among the spray variables, render optimization and control of this process are quite complex. Understanding relationships between coating properties and process parameters is mandatory to optimize the process technique and the product quality. We are interested in this work to build an on-line control model for the APS process based on the elements of artificial intelligence and to build an emulator that replicates the dynamic behavior of the process as closely as possible.

Study on optimization of underlying coal bed exploited depth for tunnel

Combined with highway construction, the analysis on the relationship betweentunnel construction and coal resource exploitation was processed, which was based onthe research of rational exploitation depth of coal.3D FEM numerical analysis for tunnelexcavation was carried out according to engineering geological features of coal measurestrata in the project area.Based on the analysis of displacement and stress of the surroundingrock in the tunnel after excavation, the characteristics for displacement andstress of the tunnel support structure were analyzed when the underlying coal bed wasexploited with sublevel and full caving method.In addition, combined with the related codeand standard, the economic and safe prohibiting exploited depth of the underlying coalbed was proposed, so that a scientific basis for tunnel construction of coal measure strataand reasonable exploitation of the mineral resources in complex geological conditions canbe offered.

Study on ultrasonic spray technology for the coating of vascular stent

The ultrasonic spray technology is studied by the method of theoretical derivation, CFD simulation, spray particle diameter detection and analysis, and experimental analysis. And the ultrasonic spray process for the coating of vascular stent is also optimized. Firstly, the ultrasonic atomization physical model is established and the equation of atomization particle diameter is derived. Secondly, the ultrasonic atomization process is simulated by the CFD method, and shows three atomization patterns： incomplete atomization pattern, critical atomization pattern and jet atomization pattem. The critical amplitude and power equation for ultrasonic atomization is derived. Thirdly, experiment is conducted to study the influence of parameters including power, gas pressure, and surface tension. The results show that the spray is stable though few particles are likely to collide each other during spray moving, and the droplet diameter is about 10μm. The Rosin-Rammler distribution equation for ultrasonic spray is created, and the uniform index number is between 7.11 and 11.48. The uniformity of spray particle diameter, the efficiency of adjustment and the energy consumption are better than traditional spray technology. Lastly, the ultrasonic spray process parameters for stent coating are optimized to eliminate the common defects and obtain fine coating.

Efficient link scheduling with joint power control and successive interference cancellation in wireless networks

Existing works have addressed the interference mitigation by any two of the three approaches: link scheduling, power control, and successive interference cancellation(SIC). In this paper, we integrate the above approaches to further improve the spectral efficiency of the wireless networks and consider the max-min fairness to guarantee the transmission demand of the worst-case link. We formulate the link scheduling with joint power control and SIC(PCSIC) problem as a mixed-integer non-linear programming(MINLP), which has been proven to be NP-complete. Consequently, we propose an iterative algorithm to tackle the problem by decomposing it into a series of linear subproblems, and then the analysis shows that the algorithm has high complexity in the worst case. In order to reduce the computational complexity, we have further devised a two-stage algorithm with polynomial-time complexity. Numerical results show the performance improvements of our proposed algorithms in terms of the network throughput and power consumption compared with the link scheduling scheme only with SIC.