磷矿山开采系统对黄柏河东支的影响研究

从黄柏河东支流域磷矿山绿色开发要求出发，基于地表水环境系统和矿业开采的耦合影响作用，开展了磷矿山开采对黄柏河东支的水环境的影响研究。通过定量和定性分析，在磷矿山开采过程中对黄柏河东支的各种影响因素中，矿井涌水(占比为43.19%)、尾渣淋溶水(占比为15.51%)、矿废石淋溶水(占比为14.64%)和生产废水(占比为10.84%)为磷矿山开采对黄柏河东支水环境的主要影响因素，尤其是矿井涌水携带的总污染物量大，影响占比接近50%。该研究影响分析为黄柏河东支水环境的治理提供有力指引支撑。     

具有双通道数据包丢失的Delta算子系统故障检测

研究同时存在双通道数据包丢失和时变时延的Delta算子网络控制系统（NCSs）故障检测问题.假定数据包丢失发生在控制器到执行器、传感器至控制器的数据传输过程中，并且利用两个相互独立的伯努利随机变量描述是否发生丢包.将上述的NCSs建模为网络切换系统，提出任意切换律下故障检测滤波器的设计方法.利用线性矩阵不等式（LMIs）方法、Lyapunov-Krasovskii泛函和平均驻留时间等得出所考虑的网络切换系统具备指数均方稳定性的充分条件.证明了所用的网络切换系统满足H_∞性能，并推导出了滤波器参数的显式表达.数值仿真结果验证了所提方法的有效性.     

A probabilistic approach to stability and stabilization of networked control systems

In this paper, a probabilistic approach is proposed to study the modeling, stability, and stabilization problems for networked control systems (NCSs) with simultaneous random network communication delay and data dropout. Different from existing modeling approaches, the proposed NCSs model naturally captures the stochastic characteristics of the considered NCSs by taking into account the effects of the random network communication delay and data dropout. Based on the developed NCSs model, necessary and sufficient conditions of stability analysis, state, and output feedback stabilization problems are tackled. Moreover, necessary and sufficient stability and stabilization conditions are also presented for the case when the occurrence probabilities of delay and data dropout are partially known. Finally, three numerical examples are provided to demonstrate the effectiveness and the reduced conservatism of the proposed method. Copyright © 2014 John Wiley & Sons, Ltd.     

Event-triggered controller design of nonlinear discrete-time networked control systems in T-S fuzzy model

This article is concerned with event-triggered fuzzy control design for a class of discrete-time nonlinear networked control systems (NCSs) with time-varying communication delays. Firstly, a more general mixed event-triggering scheme (ETS) is proposed. Secondly, considering the effects of the ETS and communication delays, based on the T-S fuzzy model scheme and time delay system approach, the original nonlinear NCSs is reformulated as a new event-triggered networked T-S fuzzy systems with interval time-varying delays. Sufficient conditions for uniform ultimately bound (UUB) stability are established in terms of linear matrix inequalities (LMIs). In particular, the quantitative relation between the boundness of the stability region and the triggering parameters are studied in detail. Thirdly, a relative ETS is also provided, which can be seen as a special case of the above proposed mixed ETS. As a difference from the preceding results, sufficient conditions on the existence of desired fuzzy controller are derived to ensure the asymptotic stability of the closed-loop system with reduced communication frequency between sensors and controllers. Moreover, a co-design algorithm for simultaneously determining the gain matrices of the fuzzy controller and the triggering parameters is developed. Finally, two illustrative examples are presented to demonstrate the advantage of the proposed ETS and the effectiveness of the controller design method.     

Flame characteristics of premixed H2-air mixtures explosion venting in a spherical container through a duct

The explosion venting duct can effectively reduce the hazard degree of a gas explosion and conduct the venting energy to the safe area. To investigate the flame quantitative propagation law of explosion venting with a duct, the effects of hydrogen fraction and explosion venting duct length on jet flame propagation characteristics of premixed H₂-air mixtures were analyzed through experiment and simulation. The experiment results under initial conditions of room temperature and 1 atm show that when hydrogen fraction was high enough, part of the unburned hydrogen was mixed with air again to reach an ignitable concentration, resulting in the secondary combustion was easier produced and the duration of the secondary flame increased. With the increase of venting duct length, the flame front distance and propagation velocity increased. Meanwhile, the spatial distribution of pressure field and temperature field, and the propagation process and mechanism of the flame venting with a duct were analyzed using FLUENT software. The variation of the pressure wave and the pressure reflection oscillation law in the explosion venting duct was captured. Therefore, in the industrial explosion venting design with a duct, the hazard caused by the coupling of venting pressure and venting flame under different fractions should be considered comprehensively.     

Reacting flow coupling with thermal impacts in a single solid oxide fuel cell

Thermal impacts are the major concern for the designs of electrolyte of Solid Oxide fuel cells (SOFCs) due to the high temperature operating conditions. In this study, the coupling dynamics of electrochemical reacting flows with heat transfer and generations of thermal strains and stresses (thermal impact) of solid electrolyte and porous electrodes are investigated in a single SOFC by numerical simulations. Modeling results from a test case show that the coupling is necessary as the electrochemical and thermal properties of the cell strongly depends on temperature, meanwhile, the thermal strains and stresses on temperature gradients. The differences in current density and thermal strain gradients predicted by coupling and decoupling simulations are as larger as 20% because of the strong dependents of ionic conductivity of the electrolyte material on temperature, the maximum thermal strain, thermal stresses, and temperature are all about 5%. It is identified that the high operation voltage benefits to the thermal strain, which decreases 20% when the cell operating from 0.5 V–0.7 V.     

矿山陡坡铁路受力分析的有限元方法

考虑矿区线路的实际工况，建立了包括轨道结构和车辆结构的耦合动力系统模型。将线路结构离散为不同的单元，采用能量原理导出了系统动力方程，进一步建立了系统的动力矩阵。得出了车辆走行过程中的轨道位移、速度、加速度等动力响应结果及受力情况，特别对坡度这个影响因素进行了分析。结果表明了有限元方法应用于陡坡铁路计算的正确性和实用性。     

新型改性矿物填料应用于橡胶/PVC弹性体

对矿物填料进行适当的改性处理，使橡胶／PVC弹性体具有明显的补强效果。探讨了矿物填料、偶联剂对橡胶／PVC弹性体力学性能的影响。     

模型锚杆腐蚀耦合效应试验研究

锚杆腐蚀耦合效应问题研究是锚杆耐久性研究的难点问题之一。本文概述了早期埋设在工程现场的尚在研究锚杆腐蚀耦合效应的一批缩尺锚杆的腐蚀环境、试验方法、试验结果和结论，可供读者参考。