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The paper Introduces the structure composition and performance characteristics of the large partical size and porous rubber modified asphalt mixture, analyses the road performance of mixtures, on the basis of the characteristics of higher proportion of coarse aggregate and poriness, puts forward the practical and feasible construction scheme. It will be a beneficial exploration for the development and application of the large partical size and porous rubber modified asphalt mixture in the "white and black" pavement structure.

Effect of pulsed magnetic field treatment on the microstructure and mechanical properties of Mg97Y2Zn1 alloy has been investigated. When the pulsed magnetic field is applied on the alloy in semi-solid state, the α-Mg was modified from developed dendrite to fine rosette, resulting in a refined solidification microstructure with the grain size decreased from 4 mm to 0.5 mm. The volume fraction of the second phase ( X phase) increased by about 10 %. The yield strength, fracture strength and plasticity were improved by 21 MPa, 38 MPa and 2.4 %, respectively. The improvement of mechanical properties was attributed to the refined grain size and increased volume fraction of X phase.

The one-droplet-per-pulse transfer is widely considered to ensure the stability of the welding process in pulsed MIG welding; a peak pulse followed by a median pulse in a square wave pulse can effectively enhance droplet transfer controllability and improve weld appearance. The instantaneous current and voltage waveforms, the probability density distributions of current and voltage, and U-I graphs collected by the waveform wavelet analyzer were used to assess the welding quality and weld bead appearance. The 1.2-mm carbon steel welding wire experiments showed that under the same conditions, using a median waveform could significantly improve the welding quality. If the median current was too small or too large, the influence on the welding process was not obvious, and was only representing an increase of the base current or peak current phase. If the median time was too short, the energy accumulated was not enough to control the droplet transfer; conversely, too much median time led to globular droplet transfer. With a backward median current range of 180A-225A and duration range of 8ms-12ms, all experiments resulted in a nice weld effect.

Use polyurethane rubber composite modified asphalt.Through the Marshall test and rutting test, test of polyurethane rubber asphalt mixture high temperature stability, low temperature crack resistance and water damage resistance, verify the composite modification advantages.

An ultrasound-assisted procedure for the extraction of pectin from heads ofHelianthus annuusL. (sunflower) was established. A Box–Behnken design (BBD) was employed to optimize the extraction temperature (X1: 30–50°C), extraction time (X2: 20–40 min) and pH (X3: 2.5–3.5) to obtain a high yield of pectin with high degree of esterification (DE) from sunflower heads. Analysis of variance showed that the contribution of a quadratic model was significant for the pectin extraction yield and DE. An optimization study using response surface methodology was performed and 3D response surfaces were plotted from the mathematical model. According to the RSM model, the highest pectin yield (23.11 ± 0.08%) and DE (39.85 ± 0.14%) can be achieved when the UAE process is carried out at 50°C for 40min using a hydrochloric acid solution of pH 3.0. These results suggest that ultrasound-assisted extraction could be a good option for the extraction of functional pectin from sunflower heads at industrial level.

Based on the nanoporous network structure features of silica aerogel, the gas-solid coupled heat transfer model of silica aerogel is analyzed, and the calculation formulas of the gas-solid coupled, the gas thermal conductivity and the heat radiation within the aerogel are derived. The thermal conductivity of pure silica aerogel is calculated according to the derived heat transfer model and is also experimentally measured. Moreover, measurements on the thermal conductivities of silica aerogel composites with different densities at ambient conditions are performed. And finally, a novel design of silica aerogel based integrated structure and thermal insulation used for withstanding the harsh thermal environment on the Martin surface is presented.

The technology was put forward on mould broken areas 3D digital remanufacturing. Based on CAD and laser cladding, it is finished including 3D repairing-trajectory modeling, editing manufacturing program and laser cladding processing. The pre-processing tasks are the experiment of laser cladding parameter, the broken areas pretreatment and measurement, and the repairing task is finished by machining after laser cladding.

The mold’s broken area is irregular, so it is difficult to model by traditional method. It puts forwards to remodel the mold’s broken area by Reverse Engineering technology. Non-contact measurement and contact measurement are both used to measure the broken mold. The pretreatment tasks are done including the point cloud data reduction Chord where the deviation sampling method is used. The surface model of the mold is remodeled and solidified. The broken area is extracted and solidified, and it provides the important data for the following repairing work.

In this paper, an energy-efficient multicast routing algorithm in multi-hop wireless networks is proposed aiming at new generation wireless communications. Different from the previous methods, this paper targets maximizing the energy efficiency of networks. In order to get the optimal energy efficiency to build the network multicast route, our proposed method tries to maximize the network throughput and minimize the network energy consumption by exploiting network coding and sleeping scheme. Simulation results show that the proposed algorithm has better energy efficiency and performance improvements comparing with the existing methods.

The semi-solid metal (SSM) processing, including thixoforming and rheocasting, offers the opportunity to manufacture net-shaped components with complicated shape and good mechanical properties. More and more researches have been focused on rheocasting in recent years because of its low cost and high productivity [1,. Rheocasting involves stirring the solidifying alloy to prepare non-dendritic semisolid slurry, then shaping the slurry directly. Ultrasonic vibration (USV) has the potential to be a simple and effective process to produce semisolid metal slurry. Previous investigations have revealed that when USV is applied on the solidifying melt, microstructure changes occur involving grain refinement, increased homogeneity, reduced micro-segregation as well as degassing [3-.

The ball mills, which have great energy consumption, are commonly used in coal-fired power plant. The key to reduce their energy consumption is to determine the best ball loading, the optimum gradation and the complement parameters. The premise of determining these parameters is to give the balls wear law. The wear matrix model, which determines the balls probability distribution through their diameters, is one of the practice methods to determine the balls attrition rule. This study assessed the wear law through the change of balls weight, determines the program feasibility and the test time through the test of a ball mill.

The effects of ultrasonic vibration (USV) on the solidified microstructure of AZ61 magnesium alloy were investigated. The experimental results show that the remarkable microstructural refinement is achieved when the USV was applied to the solidification of the AZ61 alloy. The average grain size is decreased from 263 μm without ultrasonic treatment to 98 μm with USV treatment. The microstructure evolution reveals that the primary α-Mg generates and grows in globular shape with USV, contrast with the dendritic shape without USV. The USV causes melt convection during solidification, which makes the temperature of the whole melt homogenized, and produces an undercooling zone in front of the liquid/solid interface, which makes the nucleation rate increased and big dendrites prohibited. In addition, the β-phase in the entire cross-section of the billet is significantly refined and also changed from continuous to discontinuous morphology. Spherical β-phase is formed during the solidification of billet treated with USV.

In order to follow the technical progress in the filed of aeronautics and astronautics, a numerical investigation into flow characteristic of two-phase flow under high gravity (hi-g) condition is performed. Using the CFD code CFX, the two-phase flow in orthogonal pipe under high gravity condition has been evaluated, and the effects of hi-g on two-phase flow characteristic have been analyzed. Compared with the static condition, the flow pattern, volume fraction, velocity and pressure distributions, pressure drop through the pipe are quite different under hi-g, depending on the magnitude and direction.

It is generally considered, as the material basis of human survival and production, materials industry is one of the main reasons causing energy shortages, excessive consumption of resources and environmental pollution, the issues on ecomaterials life cycle assessment are also increasingly subject to attention. In this paper, Fuzzy decision trees is applied due to they are powerful, top-down, hierarchical search methodology to extract human interpretable classification rules. And Fuzzy ID3 algorithm is used, a popular and particularly efficient method, to construct fuzzy decision tree. We use weighted fuzzy production rules generated from FDT to establish assessment model. In addition, a new method is proposed, based on fuzzy rules and degree of confidence, to set the band of assessment. Classification accuracy was used to examine results of the system. The results indicated that the system is very valid for eco-materials life cycle assessment.

The division of geohydrologic unit is the base of regional hydrogeologic research. Based on the weakness of the traditional method of dividing geohydrologic unit, the division method of geohydrologic unit based on hydrochemical characters of groundwater is put forward. The division of geohydrologic unit on Cambrian limestone in Pingdingshan coal field is done with Fuzzy C-Means Cluster, and the result is satisfying. It provides a new theoretical method for division of geohydrologic unit.

Based on the engineering that shield machine’s passing through a vertical shaft in urban rail transit construction, two methods are proposed according to the engineering geology and construction organization and finite element model is established to simulate the real situation. After the technical analysis and safety analysis of the two methods, the recommended method is given, also given are the corresponding safety measures and construction procedure. The success of this engineering proves that this analysis is reasonable and the safety measures are worth of referring to.

In order to improve the characteristic and control strategy in transmission lines, a tension stringing mathematical model was established which analyzed the multiple disturbance factors of tension. According to the tension control principle of hydraulic system and the influence of different factors, a control method of constant tension adapted to the system was proposed based on pressure regulating plan. By simulation, the modified tension control system enhanced the dynamic response characteristic and stability effectively, which can realize the ideal constant tension control.

The microstructures and tribological properties of materials for friction pairs used to space docking were investigated by optical metallographic microscope and a special home-made tribo-tester, respectively. The results demonstrate that friction material appears homogeneous and compact microstructure. Counterpart material presents temper sorbite which keeps martensite morphology and residues a small amount of blocky undissolved ferrite; the porosity of friction material is about 3.7%. Materials for space docking show favorable rigidity; during running-in, friction torque of friction pairs can be enhanced obviously; under different operation conditions, friction pairs for space docking possesses different friction coefficient.

According to the components, mechanical properties of difficult-to-process material (26NiCrMoV145)as well as characteristics of high-speed machining, modelling and prediction of cutting force in high-speed milling is studied. Based on geometry model of ball end mill edge line, milling force model of helical ball milling cutter is established by theoretical analysis and empirical coefficient. Then, simulation prediction of cutting forece is conducted under different circumstances. The experimental result shows that the predicted cutting force is consistent with experimental data and the established model is reasonable. The article contributes to the milling of difficult-to-process material, which improves security and productive efficiency in processing.

An identification method of spindle bearing fault based on rough sets theory is proposed in the article. By collecting bearing’s typical fault signal and using signal information processing techniques, vibration fault data is obtained. Then, equidistant clustering analysis method is introduced into discretization of experimental data of continuous attributes. In this way, vibration fault data table meets the requirement of rough sets data analysis. Besides, attribute importance algorithm is used in order to realize the reduction of condition attribute in the decision table. Thus, fault information which hidden in huge signal data is extracted. Therefore, simple and clear fault pattern rules are acquired. The result indicates that the method can realize fault pattern identification of spindle’s bearings and it is of great application value in practical fault pattern identification.

In order to reduce the catastrophic optical damage ( COD ) in the cavity surface of the traditional GaAs-LDs, this paper proposed the use of AlN film prepared as a non-absorbing window near the cavity surface of GaAs-LDs. In order to validate its feasibility, first of all, we prepared AIN film with different thickness on GaAs chips by reactive magnetron sputtering technology, and then, the PL spectroscopy of AlN / GaAs surface was acquired, the residual stress of the structure was calculated in accordance with the wavelength drift of GaAs intrinsic peak with the change in testing temperature.The experimental results show that the compression stress on GaAs chip is obvious when the thickness of AlN film is above 0.8 um. After the GaAs chip is subjected to compressive stress, the band gap will be widened,so the Eg of the active region near window area of GaAs-LDs will be wider than one of the active region inner the cavity, so that when the photons pass through this area, the absorption will be reduced, thereby forming non-absorbing window,therefore, the experimental validated that the AlN film used as the non-absorbing window of GaAs-LDs is feasibility.

The dynamic response of the slider to external interference is analyzed through solving eqations simultaneously of the momentum equations and the time-dependent modified Reynolds equation based on the FK-Boltzmann modified model. Analysis software of autonomous copyright was produced, and the number of the copyright is 2009SR039126. Using this software, the dynamic response curves of the slder under different shocks were obtained, and the numerical results show that under an external motivation the significant vibration is produced. but the slider is capable of returning to the equilibrium position in 0.006ms. Then the lubrication function parameters are calculated, and variable rules of the values also were analyzed. The results shows the oscillation of slider in up-and-down direction have a larger effect on the film lubrication function, yet in the rolling direction the influence is the smallest. Consequently, the fluctuation in up-and-down direction is the main factor of affecting the dynamic lubrication function.

In this paper, a spectral element method (SEM) is applied to simulate the axisymmetric flow in Czochralski crystal growth. The coordinate singularity for 1/r at r=0 is avoided by using the Gauss-Radau type quadrature points for the spatial discretization. The SEM solver is validated by its application to the benchmark problems suggested by Wheeler [1]. The stream function is solved by an artificial Poisson equation with the present method. The results show that it agrees well with available data in the literatures.

Vitamin E microcapsules prepared using spray drying were applied to fabrics in thefinishing processby means of padding, and characterization of microcapsules was studied.Experimental conditions for the textile padding process were based on industrial requirements.Morphologies and core-shell structure of the microcapsules and particle size distribution were studiedusing scanning electron microscopy, transmission electron microscopy, and a particle size analyzer.The effectiveness of textile padding (adherence state of microcapsules on textiles and washingfastness) was evaluated by scanning electron microscopy and ultraviolet spectrophotometry. Basedon the present reseach, vitamin E successfully adhered to textiles, and a kind of skin-care product hasbeen developed.

We study the effect of force convection and temperature on the double dendrite growth during the solidification of binary alloy using a phase-field model. The mass and momentum conservation equations are solved using the Simple algorithm, and the thermal governing equation is numerically solved using an alternating implicit finite difference method. The results indicate that dendritic grows unsymmetrically under a forced flow, the growth velocity of the upstream tip is faster than the downstream tip. The downstream tip of the first dendrite and the upstream tip of the second dendrite are influenced each other, the upstream tip of the second dendrite will Coarsen, and the concentration at the boundary between them is the highest. Moreover, the interaction between the two dendrites is more and more obvious with the increasing of the temperature.

Silicon is widely used as substrate material for the fabrication of micro-electro and micromechanical components. Since silicon is very brittle, how to cut it into complex shapes remains a hot topic. Thanks to the small spot diameter, laser cutting is a promising alternative. However, during laser cutting, different kinds of defects can be generated depending on the beam-material interaction phenomena (ablation, melting, etc). Molecular Dynamics simulation is an effective way to study the beam-material interaction phenomena. Lots of work has been done to develop MD models of laser ablation of silicon. However, due to lack of support from high performance parallel simulation platform, the scale of the molecular systems is limited. This paper presents a component-based parallel simulation platform Sensing-VISICOM, for large scale molecular dynamics simulation. To test its runtime performance, a molecular system of femtosecond laser ablation of silicon is designed and implemented under Sensing-VISICOM. The results of the simulation show the platform can scales well to millions of atoms.

In this paper, we present theoretical analysis and detailed design of a class of wireless power transfer (WPT) systems based on strong coupled magnetic resonances. We established the strong coupled resonance conditions for practically implementable WPT systems. We investigated the effects of non-ideal conditions presented in most practical systems on power transfer efficiency and proposed solutions to deal with these problems. We carried out a design of WPT system by using PCB (Printed Circuit Board) antenna pair, which showed strong coupled magnetic resonances. The innovations of our design include: (1) a new coil winding pattern for resonant coils that achieves a compact space volume, (2) fabrication of resonant coils on PCBs, and (3) integration of the entire system on a pair of PCBs. Extensive experiments were performed and experimental results showed that our WPT system setup achieved a guaranteed power transfer efficiency 14% over a distance of two times characteristic length(44cm). The wireless power transfer efficiency in this PCB based experimental system was sufficiently high to lighten up a LED with a signal generator.

This paper refers the case project of the Xi'an Subway Line 2 tunneling through the South Gate area of the Xi'an City Wall, has researched the surface settlement due to tunnel construction, and simulated the whole shield tunnel by using Flac3D numerical analysis. This paper has obtained the law of surface settlement and the influence on the City Wall in the tunnel construction by analyzing the calculation results, and simulated the effects of three protective measures which will be used in the South Gate area. The results showed that the surface settlement ratio after the piles and chemical grouting reinforcement was lower by about 25% than no reinforcement. The monitoring data showed that the result of model calculation was reasonable, and the protective measures in Condition 3 are feasible and effective.

A model for on-line calculation of equivalent stresses in steam turbine rotors has been built up based on Support Vector Machine (SVM) neural network and the finite element method. Regarding 125MW steam turbine rotor as an object, SVM method is employed as a tool to train large numbers of date about the equivalent stress of the rotor, which obtained from the finite element method. A model can be gotten after finishing training the data. Equivalent stresses of rotor obtained with finite element and SVM model are compared during cold start. Results show that similar calculation results of equivalent stress may be obtained with either finite element or SVM model. However, with the latter one, the calculation becomes easier and fast, which is applicable for on-line calculation of equivalent stresses in turbine rotors, and may serve as a reference for on-line life management of turbine rotors.

The Zhaohua is an ancient city on the Chinese Sichuan Road with more than 2000 years glorious history, and still preserve completely city gates and city walls, and the streets and lanes until now. The environment landscape space of inside and outside of the city construct were in perfect order, which were comply with “Nature and humanity” layout idea, The spatial design of whole this city has the feature of the Contrary Space Sequence combination in growth of Chinese historic ancient city. However, the Zhaohua ancient city faced with the modern spatial pattern which grows in the historical evaluation, especially with continuous exploitation of the ancient city combines with tourism economy, a problem that the space demand between residents and tourists must be arise. In the foundation of the effective protection of traditional space culture, we put forward and research to carry on space form optimization and adjustment to border space and street space, in order to meet the modern urbanization development needs, meanwhile, it has extremely important research significance to the ancient cities’ protection and the reasonable tourism development.

Aiming at a high-power turbine of a certain 1000MW electric-generating unit, three calculation schemes were programmed to calculate the thermal parameters of steam in the flow passages. The comparison and analysis between the calculating results and the design values under the turbine rated load (TRL) verified the feasibilities of the calculation schemes. The thermal parameters of steam in flow passages under variable operating conditions were also obtained by the calculation. The calculating results could be the basic data needed by thermal stress analysis and life prediction of the turbine.

To date, discrete event stochastic simulations of large scale biological reaction systems are extremely compute-intensive and time-consuming. Besides, it has been widely accepted that spatial factor plays a critical role in the dynamics of most biological reaction systems. The NSM (the Next Sub-Volume Method), a spatial variation of the Gillespie’s stochastic simulation algorithm (SSA), has been proposed for spatially stochastic simulation of those systems. While being able to explore high degree of parallelism in systems, NSM is inherently sequential, which still suffers from the problem of low simulation speed. Fine-grained parallel execution is an elegant way to speed up sequential simulations. Thus, based on the discrete event simulation framework JAMES II, we design and implement a PDES (Parallel Discrete Event Simulation) TW (time warp) simulator to enable the fine-grained parallel execution of spatial stochastic simulations of biological reaction systems using the ANSM (the Abstract NSM), a parallel variation of the NSM. The simulation results of classical Lotka-Volterra biological reaction system show that our time warp simulator obtains remarkable parallel speed-up against sequential execution of the NSM.I.IntroductionThe goal of Systems biology is to obtain system-level investigations of the structure and behavior of biological reaction systems by integrating biology with system theory, mathematics and computer science [1][3], since the isolated knowledge of parts can not explain the dynamics of a whole system. As the complement of “wet-lab” experiments, stochastic simulation, being called the “dry-computational” experiment, plays a more and more important role in computing systems biology [2]. Among many methods explored in systems biology, discrete event stochastic simulation is of greatly importance [4][5][6], since a great number of researches have present that stochasticity or “noise” have a crucial effect on the dynamics of small population biological reaction systems [4][7]. Furthermore, recent research shows that the stochasticity is not only important in biological reaction systems with small population but also in some moderate/large population systems [7].To date, Gillespie’s SSA [8] is widely considered to be the most accurate way to capture the dynamics of biological reaction systems instead of traditional mathematical method [5][9]. However, SSA-based stochastic simulation is confronted with two main challenges: Firstly, this type of simulation is extremely time-consuming, since when the types of species and the number of reactions in the biological system are large, SSA requires a huge amount of steps to sample these reactions; Secondly, the assumption that the systems are spatially homogeneous or well-stirred is hardly met in most real biological systems and spatial factors play a key role in the behaviors of most real biological systems [19][20][21][22][23][24]. The next sub-volume method (NSM) [18], presents us an elegant way to access the special problem via domain partition. To our disappointment, sequential stochastic simulation with the NSM is still very time-consuming, and additionally introduced diffusion among neighbor sub-volumes makes things worse. Whereas, the NSM explores a very high degree of parallelism among sub-volumes, and parallelization has been widely accepted as the most meaningful way to tackle the performance bottleneck of sequential simulations [26][27]. Thus, adapting parallel discrete event simulation (PDES) techniques to discrete event stochastic simulation would be particularly promising. Although there are a few attempts have been conducted [29][30][31], research in this filed is still in its infancy and many issues are in need of further discussion. The next section of the paper presents the background and related work in this domain. In section III, we give the details of design and implementation of model interfaces of LP paradigm and the time warp simulator based on the discrete event simulation framework JAMES II; the benchmark model and experiment results are shown in Section IV; in the last section, we conclude the paper with some future work.II. Background and Related WorkA. Parallel Discrete Event Simulation (PDES)The notion Logical Process (LP) is introduced to PDES as the abstract of the physical process [26], where a system consisting of many physical processes is usually modeled by a set of LP. LP is regarded as the smallest unit that can be executed in PDES and each LP holds a sub-partition of the whole system’s state variables as its private ones. When a LP processes an event, it can only modify the state variables of its own. If one LP needs to modify one of its neighbors’ state variables, it has to schedule an event to the target neighbor. That is to say event message exchanging is the only way that LPs interact with each other. Because of the data dependences or interactions among LPs, synchronization protocols have to be introduced to PDES to guarantee the so-called local causality constraint (LCC) [26]. By now, there are a larger number of synchronization algorithms have been proposed, e.g. the null-message [26], the time warp (TW) [32], breath time warp (BTW) [33] and etc. According to whether can events of LPs be processed optimistically, they are generally divided into two types: conservative algorithms and optimistic algorithms. However, Dematté and Mazza have theoretically pointed out the disadvantages of pure conservative parallel simulation for biochemical reaction systems [31]. B. NSM and ANSM The NSM is a spatial variation of Gillespie’ SSA, which integrates the direct method (DM) [8] with the next reaction method (NRM) [25]. The NSM presents us a pretty good way to tackle the aspect of space in biological systems by partitioning a spatially inhomogeneous system into many much more smaller “homogeneous” ones, which can be simulated by SSA separately. However, the NSM is inherently combined with the sequential semantics, and all sub-volumes share one common data structure for events or messages. Thus, directly parallelization of the NSM may be confronted with the so-called boundary problem and high costs of synchronously accessing the common data structure [29]. In order to obtain higher efficiency of parallel simulation, parallelization of NSM has to firstly free the NSM from the sequential semantics and secondly partition the shared data structure into many “parallel” ones. One of these is the abstract next sub-volume method (ANSM) [30]. In the ANSM, each sub-volume is modeled by a logical process (LP) based on the LP paradigm of PDES, where each LP held its own event queue and state variables (see Fig. 1). In addition, the so-called retraction mechanism was introduced in the ANSM too (see algorithm 1). Besides, based on the ANSM, Wang etc. [30] have experimentally tested the performance of several PDES algorithms in the platform called YH-SUPE [27]. However, their platform is designed for general simulation applications, thus it would sacrifice some performance for being not able to take into account the characteristics of biological reaction systems. Using the similar ideas of the ANSM, Dematté and Mazza have designed and realized an optimistic simulator. However, they processed events in time-stepped manner, which would lose a specific degree of precisions compared with the discrete event manner, and it is very hard to transfer a time-stepped simulation to a discrete event one. In addition, Jeschke etc.[29] have designed and implemented a dynamic time-window simulator to execution the NSM in parallel on the grid computing environment, however, they paid main attention on the analysis of communication costs and determining a better size of the time-window.Fig. 1: the variations from SSA to NSM and from NSM to ANSMC. JAMES II JAMES II is an open source discrete event simulation experiment framework developed by the University of Rostock in Germany. It focuses on high flexibility and scalability [11][13]. Based on the plug-in scheme [12], each function of JAMES II is defined as a specific plug-in type, and all plug-in types and plug-ins are declared in XML-files [13]. Combined with the factory method pattern JAMES II innovatively split up the model and simulator, which makes JAMES II is very flexible to add and reuse both of models and simulators. In addition, JAMES II supports various types of modelling formalisms, e.g. cellular automata, discrete event system specification (DEVS), SpacePi, StochasticPi and etc.[14]. Besides, a well-defined simulator selection mechanism is designed and developed in JAMES II, which can not only automatically choose the proper simulators according to the modeling formalism but also pick out a specific simulator from a serious of simulators supporting the same modeling formalism according to the user settings [15].III. The Model Interface and SimulatorAs we have mentioned in section II (part C), model and simulator are split up into two separate parts. Thus, in this section, we introduce the designation and implementation of model interface of LP paradigm and more importantly the time warp simulator.A. The Mod Interface of LP ParadigmJAMES II provides abstract model interfaces for different modeling formalism, based on which Wang etc. have designed and implemented model interface of LP paradigm[16]. However, this interface is not scalable well for parallel and distributed simulation of larger scale systems. In our implementation, we accommodate the interface to the situation of parallel and distributed situations. Firstly, the neighbor LP’s reference is replaced by its name in LP’s neighbor queue, because it is improper even dangerous that a local LP hold the references of other LPs in remote memory space. In addition, (pseudo-)random number plays a crucial role to obtain valid and meaningful results in stochastic simulations. However, it is still a very challenge work to find a good random number generator (RNG) [34]. Thus, in order to focus on our problems, we introduce one of the uniform RNGs of JAMES II to this model interface, where each LP holds a private RNG so that random number streams of different LPs can be independent stochastically. B. The Time Warp SimulatorBased on the simulator interface provided by JAMES II, we design and implement the time warp simulator, which contains the (master-)simulator, (LP-)simulator. The simulator works strictly as master/worker(s) paradigm for fine-grained parallel and distributed stochastic simulations. Communication costs are crucial to the performance of a fine-grained parallel and distributed simulation. Based on the Java remote method invocation (RMI) mechanism, P2P (peer-to-peer) communication is implemented among all (master-and LP-)simulators, where a simulator holds all the proxies of targeted ones that work on remote workers. One of the advantages of this communication approach is that PDES codes can be transferred to various hardwire environment, such as Clusters, Grids and distributed computing environment, with only a little modification; The other is that RMI mechanism is easy to realized and independent to any other non-Java libraries. Since the straggler event problem, states have to be saved to rollback events that are pre-processed optimistically. Each time being modified, the state is cloned to a queue by Java clone mechanism. Problem of this copy state saving approach is that it would cause loads of memory space. However, the problem can be made up by a condign GVT calculating mechanism. GVT reduction scheme also has a significant impact on the performance of parallel simulators, since it marks the highest time boundary of events that can be committed so that memories of fossils (processed events and states) less than GVT can be reallocated. GVT calculating is a very knotty for the notorious simultaneous reporting problem and transient messages problem. According to our problem, another GVT algorithm, called Twice Notification (TN-GVT) (see algorithm 2), is contributed to this already rich repository instead of implementing one of GVT algorithms in reference [26] and [28].This algorithm looks like the synchronous algorithm described in reference [26] (pp. 114), however, they are essentially different from each other. This algorithm has never stopped the simulators from processing events when GVT reduction, while algorithm in reference [26] blocks all simulators for GVT calculating. As for the transient message problem, it can be neglect in our implementation, because RMI based remote communication approach is synchronized, that means a simulator will not go on its processing until the remote the massage get to its destination. And because of this, the high-costs message acknowledgement, prevalent over many classical asynchronous GVT algorithms, is not needed anymore too, which should be constructive to the whole performance of the time warp simulator.IV. Benchmark Model and Experiment ResultsA. The Lotka-Volterra Predator-prey SystemIn our experiment, the spatial version of Lotka-Volterra predator-prey system is introduced as the benchmark model (see Fig. 2). We choose the system for two considerations: 1) this system is a classical experimental model that has been used in many related researches [8][30][31], so it is credible and the simulation results are comparable; 2) it is simple but helpful enough to test the issues we are interested in. The space of predator-prey System is partitioned into a2D NXNgrid, whereNdenotes the edge size of the grid. Initially the population of the Grass, Preys and Predators are set to 1000 in each single sub-volume (LP). In Fig. 2,r1,r2,r3stand for the reaction constants of the reaction 1, 2 and 3 respectively. We usedGrass,dPreyanddPredatorto stand for the diffusion rate of Grass, Prey and Predator separately. Being similar to reference [8], we also take the assumption that the population of the grass remains stable, and thusdGrassis set to zero.R1:Grass + Prey ->2Prey(1)R2:Predator +Prey -> 2Predator(2)R3:Predator -> NULL(3)r1=0.01; r2=0.01; r3=10(4)dGrass=0.0;dPrey=2.5;dPredato=5.0(5)Fig. 2: predator-prey systemB. Experiment ResultsThe simulation runs have been executed on a Linux Cluster with 40 computing nodes. Each computing node is equipped with two 64bit 2.53 GHz Intel Xeon QuadCore Processors with 24GB RAM, and nodes are interconnected with Gigabit Ethernet connection. The operating system is Kylin Server 3.5, with kernel 2.6.18. Experiments have been conducted on the benchmark model of different size of mode to investigate the execution time and speedup of the time warp simulator. As shown in Fig. 3, the execution time of simulation on single processor with 8 cores is compared. The result shows that it will take more wall clock time to simulate much larger scale systems for the same simulation time. This testifies the fact that larger scale systems will leads to more events in the same time interval. More importantly, the blue line shows that the sequential simulation performance declines very fast when the mode scale becomes large. The bottleneck of sequential simulator is due to the costs of accessing a long event queue to choose the next events. Besides, from the comparison between group 1 and group 2 in this experiment, we could also conclude that high diffusion rate increased the simulation time greatly both in sequential and parallel simulations. This is because LP paradigm has to split diffusion into two processes (diffusion (in) and diffusion (out) event) for two interactive LPs involved in diffusion and high diffusion rate will lead to high proportional of diffusion to reaction. In the second step shown in Fig. 4, the relationship between the speedups from time warp of two different model sizes and the number of work cores involved are demonstrated. The speedup is calculated against the sequential execution of the spatial reaction-diffusion systems model with the same model size and parameters using NSM.Fig. 4 shows the comparison of speedup of time warp on a64X64grid and a100X100grid. In the case of a64X64grid, under the condition that only one node is used, the lowest speedup (a little bigger than 1) is achieved when two cores involved, and the highest speedup (about 6) is achieved when 8 cores involved. The influence of the number of cores used in parallel simulation is investigated. In most cases, large number of cores could bring in considerable improvements in the performance of parallel simulation. Also, compared with the two results in Fig. 4, the simulation of larger model achieves better speedup. Combined with time tests (Fig. 3), we find that sequential simulator’s performance declines sharply when the model scale becomes very large, which makes the time warp simulator get better speed-up correspondingly.Fig. 3: Execution time (wall clock time) of Seq. and time warp with respect to different model sizes (N=32, 64, 100, and 128) and model parameters based on single computing node with 8 cores. Results of the test are grouped by the diffusion rates (Group 1: Sequential 1 and Time Warp 1. dPrey=2.5, dPredator=5.0; Group 2: dPrey=0.25, dPredator=0.5, Sequential 2 and Time Warp 2).Fig. 4: Speedup of time warp with respect to the number of work cores and the model size (N=64 and 100). Work cores are chose from one computing node. Diffusion rates are dPrey=2.5, dPredator=5.0 and dGrass=0.0.V. Conclusion and Future WorkIn this paper, a time warp simulator based on the discrete event simulation framework JAMES II is designed and implemented for fine-grained parallel and distributed discrete event spatial stochastic simulation of biological reaction systems. Several challenges have been overcome, such as state saving, roll back and especially GVT reduction in parallel execution of simulations. The Lotka-Volterra Predator-Prey system is chosen as the benchmark model to test the performance of our time warp simulator and the best experiment results show that it can obtain about 6 times of speed-up against the sequential simulation. The domain this paper concerns with is in the infancy, many interesting issues are worthy of further investigated, e.g. there are many excellent PDES optimistic synchronization algorithms (e.g. the BTW) as well. Next step, we would like to fill some of them into JAMES II. In addition, Gillespie approximation methods (tau-leap[10] etc.) sacrifice some degree of precision for higher simulation speed, but still could not address the aspect of space of biological reaction systems. The combination of spatial element and approximation methods would be very interesting and promising; however, the parallel execution of tau-leap methods should have to overcome many obstacles on the road ahead.AcknowledgmentThis work is supported by the National Natural Science Foundation of China (NSF) Grant (No.60773019) and the Ph.D. Programs Foundation of Ministry of Education of China (No. 200899980004). The authors would like to show their great gratitude to Dr. Jan Himmelspach and Dr. Roland Ewald at the University of Rostock, Germany for their invaluable advice and kindly help with JAMES II.ReferencesH. Kitano, "Computational systems biology." Nature, vol. 420, no. 6912, pp. 206-210, November 2002.H. Kitano, "Systems biology: a brief overview." 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Vitamin E (VE) microcapsules with polyurethane (PU) shell are successfully prepared via interfacial polymerization of polyurethane with toluene-2,4-diisocyanate (TDI) as the isocyanate, polyethylene glycol as the polyol, and 1,4-butanediol (BD) as the chain extender. In the preparation process, VE emulsion, prepolymer and microencapsulation of VE are studied using a particle size analyzer, butylamine titration, optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Based on the present research, VE microcapsules prepared have smooth surfaces and spherical appearances, the mean particle size of about 550 nm. Vitamin E microcapsules have been glued effectively to textiles, and a kind of skin-care product has been developed.

High performance simulation has great prospect of application in the fields of Materials Science and Engineering. In high performance simulation, high performance computers are used to improve the performance of simulation. As one of the simulation standards, HLA simulation was greatly applied in computer simulation. In HLA simulation domain, many RTIs are designed to support the simulation in LAN/WAN environment. Because of the general TCP/UDP communication mechanism, high simulation performance can’t be achieved by these software on high performance computer. To improve the simulation performance, a customized RTI software for high performance computer and PC hybrid environment is designed. By using of partially hierarchical design on functional distributed architecture, large scale simulation can be supported. An adaptive communication mechanism is proposed, which can adapt communication between different RTI components to shared memory, Infiniband and Ethernet automatically, thus can greatly improve communication performance. In addition, this paper explains the related design in this customized RTI.

The microstructure and tribological properties of space copper-based friction material fabricated by Powder Metallurgy technology were studied using optical metallographic microscope and MM-1000-type tribo-tester, respectively. The results are shown as follows: The lubricant MoS2 was resolved during sintering, resulting in the loss of S element. MoS2 and its resolvents reacted with other components into some new compounds which contribute to the tribological properties of friction material. The lubrication mechanism of these new compounds showed essential difference in comparison to that for MoS2; the friction coefficient was higher under atmospheric condition than that under vacuum conditions, but almost the same under low and high vacuum conditions. It decreased under both atmospheric and low vacuum conditions with the increase of load. The environmental temperature had insignificant effect on the friction coefficient; under atmospheric condition as load increased, the mass loss of material decreased linearly, then increased. With regard to low vacuum condition as load increased, the mass loss of material increased, then decreased; the stable coefficient of friction material under vacuum condition was higher than that under atmospheric condition.

To develop the reverse transcriptase polymerase chain reaction (RT-PCR) for the detection of European brown hare syndrome virus (EBHSV), 3 specific primers and 9 overlapping oligo primers were designed to amplify a fragment of 335 nucleotides from the genome of EBHSV according to the genome sequences published in GenBank, and a 359 bp DNA fragment of the capsid protein(VP60)gene of EBHSV was synthesized in vitro by using overlap extension PCR to construct the recombinant plasmids pGM-T-EBHSV, then the RT-PCR method was described through the optimization of reaction conditions, sensitivity and specificity tests. Results showed the RT-PCR method was supplied for the detection of EBHSV with good specificity and sensitivity. The sensitivity of the RT-PCR could reach about 50 copies of cloned viral genomic fragments (pGM-T-EBHSV), and no amplifications for RHDV, Pasteurella multocida, E.coliandSalmonellafrom rabbits detection by this approach.

The characteristics of deformation and strength of soils under the plane strain condition can be simplified as a two-dimensional problem. How to easily and reasonably determine the value of principal stress in the direction of plane strain is the key point. Based on the Elastic-plastic stress-strain relationship for soil and test data under the plane strain condition, it is assumed that the relationship between principal stresses in plain strain direction and the principal stresses in the other directions is bilinear. The parameters of bilinear function are determined by one-dimensional consolidation and failure state. The principal stress in plain strain direction is expressed as a function of stress states and material properties. Compared with test results, the rationality of the proposed bilinear principal stress function is testified.

In allusion to facility corrosion problem in caustic soda industry five types of ni-Cr-cu alloy cast irons were developed. The corrosion rates of ni-Cr-cu alloy cast irons in hot concentrated alkali solution were measured by using self-made dynamic corrosion experiment equipment; the microstructures and surface corrosion morphology of alloy cast irons were observed by means of the optical microscope and SEM; the composition was analyzed using XES. Corrosion resistance mechanism were discussed detailedly. the experimental results showed that ni-Cr-cu cast iron was uniform corrosion macroscopically in the dense caustic soda at high temperature and there was ni, cu enrichment microcosmically. The Ni and Cu enriched in the matrix , which increase in local electrode voltage of the matrix,are advantageous to the improvement of caustic corrosion resistances of that zone. The higher Ni content,the better alkali corrosion resistance performance with high temperature.

In this work, a visible photocatalytic system containing Eosin Y, multiwalled carbon nanotubes and CuO was prepared. The photocatalytic hydrogen evolution from water over this system was studied using triethanolamine (TEA) as a sacrificial reagent. The results indicated that it was an efficient photocatalyst with an average rate of H2 evolution of 373 mmol·h-1·g-1 during first three hours under visible irradiation.

In the presence of Cu2+ ions, the photocatalytic hydrogen evolution from a methanol aqueous solution was achieved when potassium hexaniobate nanotubes were used as the catalyst. It was found that there existed a photo-induced period in the initial reaction stage. Furthermore, the photo-induced period was prolonged by increasing the amount of Cu2+ ions. After that, the rate of hydrogen evolution was dramatically improved. Combined with the reaction phenomena and the result of the photocatalytic hydrogen evolution, it was deduced that the Cu2+ ions captured the photo-generated electrons of potassium hexaniobate nanotubes in the photo-induced period. Consequently, the Cu2+ ions were reduced and deposited on the potassium hexaniobate nanotubes. When the mass ratio of Cu to potassium hexaniobate nanotubes was 3 wt%, the rate of hydrogen evolution over the catalyst reached 21.9 mmol·g-1·h-1, which could almost match with Pt as a co-catalyst. These results showed that Cu was an effective alternative to Pt as a co-catalyst of potassium hexaniobate nanotubes for the photocatalytic hydrogen evolution from the methanol aqueous solution.

The pompon-like microspheres of AgIn5S8 with a cubic phase were prepared in a low temperature aqueous solution using mercaptoacetic acid as capping agent and thioacetamide as sulfur source and characterized with XRD, UV-vis absorption spectra, SEM and BET analysis. It is interesting that the microspheres are quite open and puffy. More importantly,the obtained microspheres showed remarkable photocatalytic activity for the degradation of methyl orange under visible light irradiation, which is probably due to the pompon-like morphology for providing reactive sites and facilitating the charge transfer between the target pollutant and the photocatalyst. This method could be extended to the synthesis of other functional micro/nano materials.

Due to the establishment of thermal equilibrium is very rare, some cases not possible, so the accuracy of temperature measurement is often difficult to ensure that no one will be allowed or asking for too much more to the transient temperature measurement is difficult. Based on the finite element software ANSYS platform, according to the feature of fusion welding, the impact of heat on the welding and the welding temperature field is simulatd by the Three-Dimensional Dynamic FEM simulation of the ANSYS software. Finite element numerical simulation results with the test weld shape with good consistency, so that the body welding Gauss heat source model is used to simulate the temperature field is reasonable.

Amorphous InAsSb films and hydrogenated InAsSb films are deposited on substrates of quartz glass and silicon by rf magnetron sputtering technique in different gas ambient. The effect of H addition on structure, optical properties and electrical properties of a-InAsSb is studied. It is found that the bonded hydrogen content increases with increasing H2 to Ar flow rate radio(R). When R is 0.1, Hydrogen addition shifts the optical absorption edge to higher energy, decreases the dark conductivity and improves the photo-sensitivity. However, hydrogen addition produces the crystallization of the film at R>0.1. Moreover the optical gap, dark conductivity and photo-sensitivity of the films have a reverse change compared with that in R=0. These results demonstrate that hydrogen has obvious passivation effects on rf sputtered amorphous InAsSb thin films only at R=0.1.

We present a systematic study of the effect of the sputtering parameters on the structure and composition of InSb film. The effect of the sputtering parameters on the crystallographic structure of InSb films is discussed in terms of the kinetic energy of the particle bombarding the growing film. Measurements of the chemical composition show that In to Sb concentration ratio increases with the increase of working pressure because Sb atoms are more rapidly thermalized by collisions with argon atoms during the transport process of the sputtered atoms. And the composition of the films is governed by the Sb re-evaporation process at the surface of the growing films. In to Sb concentration ratio is enhanced by increasing the substrate temperature (essentially) or RF power.

The analysis on ingredient and petrographic examination of 5mm thickness ANF-6 electroslag fluxes (70% CaF2 + 30% Al2O3) skin formed during 0.45C steel 260 kg ingot remelting by electroslag remelting furnace with 160 kW, Φ100 mm × 350 mm mould indicates that the lamination phenomenon of fluxes is observed, and the Al2O3 content in fluxes skin near mould side and near electroslag ingot side is higher 69.24%-75.62%, and the CaF2 content is 21.46%-28.36%, where at skin center 3 mm location, the Al2O3 content in fluxes skin is only 15.84% and the CaF2 content is 81.06%. The solidification mechanism of “ring shaped miniature fluxes pool” formed at upper edge of remelted ingot is advanced in this paper, and the surface quality of ingot by using large over-cooling and low melting-point fluxes is higher than that by using low over-cooling and high melting-point fluxes.

Al–Si alloy-based composites are widely used in automotive, aerospace and mineral processing industries with improved properties. In situ techniques have been developed to fabricate Al–Si alloy-based composites, which can lead to better adhesion at the interface and hence better mechanical properties. Al–Si alloy reinforced with in situ TiB2 particles was synthesized successfully by using salt reaction route. These in situ composites have shown significant improvement in mechanical properties compared with the base alloy. The wear resistance of the alloy is also significantly improved with the addition of TiB2 particles. The hardness, strength and wear resistance are strengthened with increasing TiB2 content of the composites. TiB2 can act not only as a grain refiner for primary Al but also as a modifier of Si in eutectic mixture. Analysis of the worn surface of Al–Si/TiB2 composites tested under loads of 30 and 110N suggests that ploughing is predominant at lower loads and delamination is predominant at higher loads.

TiC reinforced AZ91 magnesium matrix composites have been fabricated by a melt in-situ reaction spray deposition. The microstructures of spray-deposited alloys were studied by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The dry sliding wear behavior of the alloys was investigated by using a pin-on-disc machine under five loads, namely 10, 20, 30, 40 and 50 N. It has been found that the wear behavior of the alloys was dependent on the TiC content in the microstructure and the applied load. At a lower load (10 N), with increasing TiC content, the wear rate of the alloy was decreased, and the dominant wear mechanism was an oxidative mechanism. At a higher load (50 N), a spray- deposited AZ91/TiC composites exhibited superior wear resistance to the AZ91 magnesium alloy, the dominant wear mechanism was delamination.