Multi‐surface sliding control for fast finite‐time leader–follower consensus with high order SISO uncertain nonlinear agents

In this paper, multi surface sliding cooperative control scheme is presented and new multiple sliding surfaces are proposed. It is proven that, for the setup that each agent is described by a chain of integrators, where the last integrator is perturbed by a bounded disturbance, leader–follower consensus can be achieved on these sliding surfaces if the communication graph has a directed spanning tree. Also, sliding variables can be driven to the sliding surfaces in fast finite time by the nonsmooth control law. The fast finite‐time Lyapunov stability theorem, the terminal sliding control technique, and the adding a power integrator design approach are used in our proposed control. Simulation results demonstrate the effectiveness of the proposed scheme. Copyright © 2013 John Wiley & Sons, Ltd.     

撞击流反应器流场的有限元分析初探

撞击流已被证明是强化相间热质传递最有效的方法之一，作为一种新型的反应器——浸没循环撞击流反应器，在液相和液固相反应极具应用开发潜力。本文用有限元软件ANSYS／FLOTRAN对其三维流场进行模拟和分析。结果表明SCISR流场中各参数关于Y轴完全对称；撞击区速度和压力都较大，撞击区静压高，且在驻点达到最大值。     

0.3%印楝素乳油防治水稻二化螟药效试验

0.3%印楝素乳油对水稻二化螟有较好的防治效果,用药后14 d防效达90%左右,而且对稻株无药害,可以作为当前防治二化螟的选择药剂。     

啮合同向双螺杆挤出过程非啮合开槽螺纹元件组合流道三维流场分析

应用ANSYS有限元分析软件对啮合同向双螺杆挤出过程包括非啮合多过程螺纹元件（NI-MPE）组合流道进行了等温非牛顿三维流场模拟分析，得到了包括NI-MPE元件的组合流道的压力场、速度场、剪切速率场和剪切应力场，并与包括非啮合常规螺纹元件的组合流道的模拟结果进行了对比。     

多孔催化剂效率因子的多组分扩散模型(Ⅴ) 表面中毒并伴有平衡死区圆柱状催化剂效率因子的有限元求解

针对表面中毒并伴有平衡死区二维圆柱状催化剂的反应-扩散偏微分方程组的特殊性,引入有限元方法求解该类问题,建立了求解步骤。实际计算所得效率因子与实验值对照表明,本法结果准确,过程简单,容易推广应用于各种相类似的体系。     

Unsteady temperature fields of monoliths in catalytic converters

This paper measured unsteady temperature fields of uncoated-monolith and catalytic monolith under real engine operating conditions using thermocouples. A multi-dimensional flow model of the turbulence, heat and mass transfer, and chemical reactions in monoliths was established and numerically solved in the whole flow field of the catalytic converter. The purpose of this paper is to study unsteady warm-up characteristics of the monoliths and to investigate effects of inlet cone structure on temperature distribution of the catalytic converter. Experimental results show that the warm-up behaviors between uncoated-monolith and catalytic monolith are quite different. Simulation results indicate that the established model can qualitatively predict the warm-up characteristics. Increasing the inlet cone angle can improve the light-off characteristics of the catalysts due to high flow velocity and high temperature in the center of the monoliths.     

中间苍白杆菌对含蜡原油除蜡降粘分析

蜡质不仅使含蜡原油黏度升高，而且会析出积聚在管壁上降低管输效率。从原油污染淤泥中分离出一株产表面活性剂的烃降解菌F-1，经16S rDNA鉴定为中间苍白杆菌。与原油作用7 d 后，能将蜡含蜡量为15.2%的高含蜡原油处理为蜡含蜡量为9.1%的含蜡原油，原油蜡质量分数降低40.1%，原油黏度降低21%以上，细胞疏水性达28.1%。通过傅里叶红外光谱鉴定该菌产生的生物表面活性剂为脂肽类。添加该菌上清液到液体石蜡 可形成91.49 mm的排油圈，能够显著降低培养基表面张力，对液体石蜡乳化系数达到65%。     

Semiochemicals and Social Signaling in the Wild European Rabbit in Australia: I. Scent Profiles of Chin Gland Secretion from the Field

The European rabbit (Oryctolagus cuniculus) uses the secretion of the chin gland in the maintenance of social status. Previous work has concentrated on secretion collected directly from the animal. In this study, the analysis was conducted by collecting scent marks made by free-ranging animals. Scent marks were found to be concentrated at the center of the area controlled by a social group, and at the boundaries between two adjacent social groups. Only the mark from dominant animals could be identified. Marks were also collected from the skin of rabbits, where they had been placed by the dominant individual. The mark found on the head of a subordinate animal may, in the future, be used to identify the dominant animal of the social group, who placed the mark.     

承压含水层地下水稳定流的有限层分析

有限层法是一种对空间某一方向进行数值离散,而在其余两方向采用连续函数的半数值半解析方法.该方法能有效地将三维问题简化为一维问题求解,从根本上解决了常用数值分析方法在模拟三维地下水运动时存在的计算工作量大、占用内存多、耗时大等缺点.文中基于有限层法的优点,推导了以伽辽金法结合贝塞耳函数为基础的层状非均质各向异性承压含水层的稳定流有限层方程,并编制了相应的计算程序.通过对2个经典算例的数值解与解析解对比分析,验证了该方法的正确性.     

销钉机筒挤出机内销钉附近物料流场分析及功率计算

采用当量粘度的方法，基于牛顿流体模型，提出销钉机筒挤出机内销钉附近流场的应力及速度分布数学模型和销钉消耗功率的计算方法。用NR／炭黑混炼胶进行的挤出过程中销钉消耗功率的研究结果表明，实测值与计算值的相对误差只有4％。