A Large Deformation Model for the Elastic Moduli of Two-dimensional Cellular Materials

1Introduction Themechanicalbehaviorofcellularmaterialsde pendsontheirrelativedensity,cellgeometryandthema terialpropertiesofthesolidfromwhichtheyaremade.Theelasticmoduliofcellularmaterialscanbederived fromananalysisofthedeformationmechanismofthecell members.Thesimplegeometryofanidealizedunitcell allowsthederivationofrelationsbetweenmicro structural featuresandeffectivemechanicalproperties.Manytheoreticalmodelshavebeendevelopedtopre dicttheelasticmoduliofcellularmaterials[14].AbdEl Sayedetal[…     

Exploration of Reactivity of Eu(TTA)2(phen)(MA)

The reactivity of Eu(TTA)2(phen)(MA) (HTTA=2-thenoyltrifluoroacetone, MA=maleic anhydride) was studied. A series of products were prepared by direct polymerization, suspension polymerization, and alternate suspension and solution copolymerization with the styrene. And then we reactivity of these products were studied. The complexes were investigated and characterized by X-ray Diffraction (XRD), gel permeation chromatography (GPC) and fluorescence spectrophotometer. Although high polymerization degree is not found in the exploration of reactivity, it is found that the fluorescent intensity of complexes prepared by suspension polymerization increases significantly compared with the original particles, which is five times higher than that of the pure rare earth complex.     

Effect of Rare Earths on Electronic Structure of (110) Twin Martensite Boundary for Ni2MnGa Alloy

The doping effect of rare earth elements (Tb and Sm) on the electronic structure of (110) martensitic twin boundary in Ni2MnGa alloys was investigated by using ab initio method within the DFT and the supercell implementation. The calculated results show that the atomic relaxation lowers the boundary energy and the segregation energy. Sm seems easier to segregate to the boundary and has a greater doping effect compared with Tb due to its lower segregation energy and bigger bonder order with neighboring atoms. Tb makes a greater contribution to the magnetic properties of the twin boundary than Sm.     

一种新颖的具有带隙结构运算放大器设计

本文提出了带隙结构的运算放大器，把带隙基准和运算放大器有机的结合到一起，有效的节省了芯片面积，并有很好的精度和动态响应特性。本文阐述了该结构的工作原理，对整体结构进行分析，重点阐述了带隙结构的特点。采用0.8μm BiCMOS工艺，通过HSPICE进行仿真验证，得到其开环增益为63.4dB，电源抑制比为106.4dB。     

带有Agent特征的全局流程集成平台研究

针对政府信息化建设中的特殊应用,借鉴MAS思想提出了全局流程的概念,并把全局流程与局部流程区分开来.在此基础上建立了全局流程集成平台,详细讨论了平台的设计思想、结构和关键的组成部分.实践表明,平台的流程描述能力强、层次结构清晰,具有通用性,能体现Agent的自治性、自主性、协作性和适应性,有效地支持了电子政务中典型应用的开发,适合作为开发以业务流程为中心的应用系统的支撑平台.     

Cones and foci: A mechanical framework for protocol verification

We define a cones and foci proof method, which rephrases the question whether two system specifications are branching bisimilar in terms of proof obligations on relations between data objects. Compared to the original cones and foci method from Groote and Springintveld, our method is more generally applicable, because it does not require a preprocessing step to eliminate τ-loops. We prove soundness of our approach and present a set of rules to prove the reachability of focus points. Our method has been formalized and proved correct using PVS. Thus we have established a framework for mechanical protocol verification. We apply this framework to the Concurrent Alternating Bit Protocol.

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Tilting Micromirror With a Liquid-Metal Pivot

In this paper, we have developed a new micromirror with a compact footprint which can be rapidly tilted to large angles. The micromirror is supported by a liquid-metal drop (LMD) with low vapor pressure and is rotated by an electrostatic torque. A torsional spring model is proposed to predict the equivalent torsional constant of the LMD and the resonant frequency of the mirror. Micromirrors (1 mmtimes1 mmtimes25 mum) and actuating electrodes are microfabricated with a centralized wetting area surrounded by a nonwetting parylene area to confine the LMD. Our measurements of the mirror show the average snap-down voltage of ~ 79 V and the resonant frequency of 165 Hz. A single mirror is actuated to steer a laser beam with a maximum deflected angle of 23.6deg. A 1times3 mirror array is demonstrated for light switching, and has greater than 1 : 64 idle/deflection contrast. We also test the stability of the mirror to mechanical shake up to 56 g (g = 9.807 m/s²). The prototype mirror has 3.6 million cycles of operation     

The control of a two-level Markov decision process by time aggregation

The solution of Markov Decision Processes (MDPs) often relies on special properties of the processes. For two-level MDPs, the difference in the rates of state changes of the upper and lower levels has led to limiting or approximate solutions of such problems. In this paper, we solve a two-level MDP without making any assumption on the rates of state changes of the two levels. We first show that such a two-level MDP is a non-standard one where the optimal actions of different states can be related to each other. Then we give assumptions (conditions) under which such a specially constrained MDP can be solved by policy iteration. We further show that the computational effort can be reduced by decomposing the MDP. A two-level MDP with M upper-level states can be decomposed into one MDP for the upper level and M to M(M-1) MDPs for the lower level, depending on the structure of the two-level MDP. The upper-level MDP is solved by time aggregation, a technique introduced in a recent paper [Cao, X.-R., Ren, Z. Y., Bhatnagar, S., Fu, M., & Marcus, S. (2002). A time aggregation approach to Markov decision processes. Automatica, 38(6), 929-943.], and the lower-level MDPs are solved by embedded Markov chains.     

Comments on: “Efficient robust constrained model predictive control with a time varying terminal constraint set” by Wan and Kothare

We present an algorithm that modifies the original formulation proposed in Wan and Kothare [Efficient robust constrained model predictive control with a time-varying terminal constraint set, Systems Control Lett. 48 (2003) 375–383]. The modified algorithm can be proved to be robustly stabilizing and preserves all the advantages of the original algorithm, thereby overcoming the limitation pointed out recently by Pluymers et al. [Min–max feedback MPC using a time-varying terminal constraint set and comments on “Efficient robust constrained model predictive control with a time-varying terminal constraint set”, Systems Control Lett. 54 (2005) 1143–1148].     

沸石、骨炭、活性氧化铝除氟效果研究

对沸石、骨炭和活性氧化铝三种除氟剂的除氟性能，处理后的水质通过静态和动态实验进行了比较，结果表明沸石价格低廉，具有越用越好的趋势，处理后的水质和水量能满足家庭饮用水的需要，适用于高氟区家庭使用，骨炭和活性氧化铝除氟效果较好，技术成熟，适用于处理厂集中处理使用。