THE GLOBAL EXISTENCE AND UNIQUENESS OF SMOOTH SOLUTIONS TO A FLUID-PARTICLE INTERACTION MODEL IN THE FLOWING REGIME

This paper is concerned with the Cauchy problem for a 3D fluid-particle interaction model in the so-called flowing regime inℝ3.Under the smallness assumption on both the external potential and the initial perturbation of the stationary solution in some Sobolev spaces,the existence and uniqueness of global smooth solutions in H3 of the system are established by using the careful energy method.

Preparation of Nitrogen-Doped Carbon Catalyst to Oxygen Reduction Reaction and Influence of Protective Gas Flowing on Its Activity

A non-precious metal catalyst MnHMTA/C to oxygen reduction reaction was prepared by py- rolyzing a precursor from manganese chloride, hexamethylenetetramine and acetylene black in nitrogen gas atmosphere. The effect of heat treatment temperature and flowing of nitrogen gas were investigated. A catalyst with the highest activity can be obtained at 700 ℃. Mn（Ⅱ） ion was changed to MnO in heat treatment, which improved the catalytic activity of the catalyst. Hexamethylenetetramine takes part in the formation of active site of the catalyst as its decomposed gases. The flowing of protective gas takes the decomposed gases out of the tube furnace and brings negative effect on the catalytic activity of the MnHMTA/C catalyst.

Comparative experimental investigation of chemical grouting into a fracture with flowing and static water

We present a series of experimental tests on chemical grouting into a fracture with flowing and static water,using a transparent fracture grouting experimental device.Variations of seepage pressure and grout propagation were compared in our investigation.The results show that flowing water results in drops of seepage pressure,development of penetration radii in the upstream side and drops of propagation area during the same period,compared with grouting in static water.The propagation area in static water is always round before grouts reach the joint boundaries.However,the propagation shape changes from round to an elliptic shape for grouting into a fracture with flowing water.A theoretical model for the grout penetration radius in a fracture considering flowing velocity was developed and validated by our experimental results.These results are helpful in improving understanding of fracture grouting mechanism and in guiding engineering practices.

Prediction of Flowing Bottomhole Pressures for Two-Phase Coalbed Methane Wells

A method is proposed to predict the flowing bottomhole pressures （FBHPs） for two-phase coalbed methane （CBM） wells. The mathematical models for both gas column pressure and two-phase fluid column pressure were developed based on the well liquid flow equation. FBHPs during the production were predicted by considering the effect of entrained liquid on gravitational gradients. Comparison of calculated BHPs by Cullender-Smith and proposed method was also studied. The results show that the proposed algorithm gives the desired accuracy of calculating BHPs in the low- productivity and low-pressure CBM wells. FBHP is resulted from the combined action of wellhead pressure, gas column pressure and fluid column pressure. Variation of kinetic energy term, compressibility and friction factors with depth increments and liquid holdup with velocity should be considered to simulate the real BHPs adequately. BHP is a function of depth of each column segment. The small errors of less than 1.5% between the calculated and measured values are obtained with each segment within 25 m. Adjusting BHPs can effectively increase production pressure drop, which is beneficial to CBM desorption and enhances reservoir productivity. The increment of pressure drop from 5.37 MPa2 to 8.66 MPa2 leads to an increase of CBM production from 3270 m3/d to 6700 m3/d and is attributed to a decrease in BHP from 2.25 MPa to 1.33 MPa.

Emergence as a process of resources flowing in supply chain system

To accurately describe the resource values that agents possess in the complex supply chain system which is a result of the interaction among the agents and to make correct decisions regarding quantity, time and place of the resources, the characteristics of the resource values in the supply chain are analyzed. ＂Chromosome＂ is used to express a resource value in the supply chain, and eight random numbers are used to integrate the resources. The if-then rules and correlation chance constrained programming in the resource supply-distribution model are set up and they are used in a three-tiered-echo model which can describe the kinds of interactive behavior of the agents in the supply chain system. Simulation is done in the platform of Swarm with a genetic algorithm. The results show that the resources in the supply chain complex adaptive system are an organic whole that cannot be separated. The three-tiered-echo model can accurately describe the interaction of resource flows of agents in the supply chain system. The system can attain optimization by utilizing the resources in the supply chain if the agents in the system cooperate, compete and distribute resources according to this model.

Analysis of Influencing Factors of Silt Solidified Soil in Flowing State

Every year, a large amount of silt is generated by river dredging. For the characteristics of dredging silt, such as high moisture content, low strength and high compressibility, the traditional solidification method can no longer better solve this kind of silt problem.?This paper mainly studies the fluidized solidification treatment of high water content sludge, not only makes the silt soil achieve a good solidification effect, but also the project cost is lower, the construction method is more environmentally friendly and green. The influencing factors of the solidified soil are mainly investigated by the unconfined compression test and the fluidity test. The experiment result shows?1)When the cement to sludge mass ratio (RCS) is 0.09?-?0.16 and the fly ash to cement mass ratio (RFC) is 0.35?-?0.80, as the amount of?RFC?increases, the flow rate of the solidified soil gradually decreases. With the increase of time, the liquidity is significantly reduced, and the influence of cement on the fluidity is greater than that of fly ash.?2) When?RCS?= 0.09?-?0.16, the strength of the sludge solidified soil at 28?d age increased by 4.5?-?6 times. 3)?When?RCS?= 0.09?-?0.16 and?RFC?= 35%?-?80%, the intensity of 14?d increased by 1.23 times than that of 7?d, and the intensity of 28 days increased by 1.29 times than that of 14?d. This experiment can provide the mix ratio design of solidified materials for different needs of the project, which can better provide a basis for engineering application and strength prediction.

Study on water treatment effect of dispersion discharge plasma based on flowing water film electrode

To improve the utilization rate of plasma active species,in this study,a closed non-uniform air gap is formed by a flowing water film electrode and a sawtooth insulating dielectric layer to realize the diffuse glow discharge in the atmosphere.Firstly,the electric field distribution characteristics of non-uniform air gap in the sawtooth dielectric layer are studied,and the influence of aspect ratio on the characteristics of diffuse discharge plasma is discussed.Subsequently,the effects of wire mesh,the inclination angle of the dielectric plate,and liquid inlet velocity on the flow characteristics of the water film electrode are analyzed.The results show that the non-uniform electric field distribution formed in the sawtooth groove can effectively inhibit the filamentous discharge,and the 1 mm flowing water film is directly used as the electrode,and high-active plasma is formed directly on the lower surface of the water film.In addition,a plasma flowing water treatment device is built to treat the methyl orange solution and observe its decolorization effect.The experimental results show that after 50 min of treatment,the decolorization rate of the methyl orange solution reaches 96%,which provides a new idea for industrial applications of wastewater treatment.

Experimental Simulation Study of Smoke Flowing Properties in Running Train

Tbe experimental simulation has been performed to investigate the smoke flowing properties within the 1/5 reduced-scale model of a sleeping carriage. The velocity field of the running train on fire is simulated in a wind tunnel of the State Key Lab of Fire Science, USTC (University of Science & Technology of China). In this paper, the fire-smoking properties and the variation of the temperature field in the sleeping carriage are analyzed. This paper introduces the simulation method of reducedscale experiment about the running train and the analysis or the experimental data. It provides the basis of experiment for the running train’s fire-safety and full-scale experiment in the future study.

ROUNDED FLOWING STATES OF OBSTRUCTED BUOYANT JET

The mutual relationships of three effective factors, the diameter D/d （d is the diameter of exit） of obstructed plate, exit densimetric Froude number and the distance Hid of the plate from jet orifice for obstructed buoyant jet in static ambient, are analyzed to explain normal and abnormal rounded flowing （reverberated and bifurcated flowing）. The critical Froude numbers for obstructed buoyant jets with H/d=2, 4, 6, 8 which distinguished normal and abnormal flowing pattern are obtained. Normal rounded flowing is found only for a plate under a special value of H/d. A fitted formula of critical Froude numbers with H/d and D/d is presented to distinguish rounded flowing types. The occurring of reverberated or bifurcated flowing in abnormal rounded flow is analyzed. Based on the results of obstructed buoyant jets with D/d=1, normal rounded flowing occurred only for all conditions and axial dilution behind the plate under different H/D is obtained.

FLOWING FILM JIGGING FUNCTION IN THE NEW″IFFC″PROCESS FOR SEPARATING MINERALS OF ULTRAFINE SIZES

The concept of the flowing film jigging was first applied to the flowing film concentration area.The flowingfilm jigging function is an important element of the new process,in jection-flowing film centrifugation(IFFC),for separating and recovering minerals of ultrafine sizes.

Investigation of semi-solid aluminum alloy filling-plastic flowing in thixoforging

The semi-solid filling-plastic flowing integrated forging process of semi-solid 6061 Al alloy was simulated by commercial finite element software DEFORM-3D.Temperature,fluid and stress-strain fields were considered in numerical simulation.The simulation results show that the plastic deformation of billet of the ends is higher than that of billet in the straight cylinder.The value of plastic deformation varies with loading mode and plastic deformation fields at the stage of increasing pressure to constant value.When the thixoforging experiments were performed at 590 ℃,15 mm/s of punch velocity and 46 MPa of pressure side urn,it gets the filling wholly and dense internal organization of semi-solid thixoforging parts is gotten.Finite element analysis results are compatible with experimental ones.

Mechanism of Flowing Stop of Al-Si Alloys in EPC Process

The effect of several casting parameters on flowability of aluminium alloys is studied.It is found that fluidity increases linearly with the increase of pouring temperature and casting section thickness;the latent heat of vaporization is one of the most important properties of polystyrene which influences the molten metal flow.Also the mechanism of metal flowing stop is studied by means of dumping tests.The results show that for pure aluminium and aluminium alloys with narrow freezing range the molten metal flowing is stopped when a solidification shell which has enough strength to resist the effective pressure head is formed at the flowing metal front.The mechanism of flowing stop is much different from that in the traditional green sand casting.

Flowing simulation of injection molded parts with micro-channel

In the micro-molding of component with a micro-sized channel, the ability for polymer melt to flowing into the micro-channel in a macro-sized part is a big challenge. The multidimensional flow behaviors are included in the injection molding the macro-component with a micro-channel. In this case, a simplified model is used to analyze the flow behaviors of the macro-sized part within a micro-channel. The flow behaviors in the macro-cavity are estimated by using the finite element and finite difference methods. The influence of the injection rate, micro-channel size, heat transfer coefficient, and mold temperature on the flowing distance is investigated based on the non-isothermal analytic method. The results show that an increase in the radius of the micro-channel and mold temperature can improve effectively the flowing distance in the micro-channel.

Energetics of Resistive Wall Modes in Flowing Plasmas

Stabilization/destabilization of magnetohydrodynamic （MHD） waves are formulated in terms of wave energy, where the waves are subject to Alfven and sound resonances and also influenced by small resistivity at conductive wall. Negative energy wave, which may exist in the presence of mean flow, is shown to be destabilized by the resistive wall, where its growth rate is characterized by the energy dissipation rate. The effect of resonance is examined as well based on a recent knowledge of wave energy for Alfv4n and sound continuum modes. Resonant coupling between an eigenmode and a continuum mode having the same sign of energy results in phase mixing （or continuum） damping. In contrast, if their signs are opposite, such resonance triggers an instability.

Sediment Load of Asian Rivers flowing into the Oceans and their Regional Variation

Study of the major Asian rivers discharge to the ocean reveals variations of their water discharges and sediment loads, and local characteristics of river sediment concentrations. On the basis of this, the Asian rivers fall into three regions, including Eurasia Arctic, East Asia, Southeast and South Asia Regions. The Eurasia Arctic Region is characterized by the lowest sediment concentration and load, while the East Asia Region is of the highest sediment concentration and higher sediment load, and the South-East and South Asia Region yields higher sediment concentration and highest sediment load.The sediment loads of these regions are mainly controlled by climate, geomorphology and tectonic activity. The Eurasia Arctic rivers with large basin areas and water discharge, drain low relief which consists of tundra sediment, thus causing the lowest sediment load. The East Asia rivers with small basin areas and lowest water discharges, drain extensive loess plateau, and transport most erodible loess material, which results in highest sediment concentration. The SE and South Asia rivers originating from the Tibet Plateau have large basin areas and the largest water discharges because of the Summer Monsoon and high rainfall influence, causing the highest sediment load.In Asia, tectonic motion of the Tibet Plateau plays an important role. Those large rivers originating from the Tibet Plateau transport about 50% of the world river sediment load to ocean annually, forming large estuaries and deltas, and consequently exerting a great influence on sedimentation in the coastal zone and shelves.

Height prediction of water flowing fractured zones based on BP artificial neural network

Factures caused by deformation and destruction of bedrocks over coal seams can easily lead to water flooding(inrush)in mines,a threat to safety production.Fractures with high hydraulic conductivity are good watercourses as well as passages for inrush in mines and tunnels.An accurate height prediction of water flowing fractured zones is a key issue in today's mine water prevention and control.The theory of leveraging BP artificial neural network in height prediction of water flowing fractured zones is analysed and applied in Qianjiaying Mine as an example in this paper.Per the comparison with traditional calculation results,the BP artificial neural network better reflects the geological conditions of the research mine areas and produces more objective,accurate and reasonable results,which can be applied to predict the height of water flowing fractured zones.

Electrical properties of carbon nanotubes in flowing vapor

Electric potentials were generated from carbon nanotubes immersed in flowing vapors. The nanomaterials used in this study were multiwall carbon nanotubes（MWCNTs） and silver nanopowders. These nanomaterials were dispersed and densely packed on a substrate and immersed in flowing vapors generated from solution such as water, ethanol and KCI. The potentials generated from these samples were measured by a voltmeter. Experimental results showed that the electric potentials were produced at the surface of the MWCNT samlpes, and strongly dependent on the pretreatment of MWCNT and properties of the flowing vapors. The mechanism of vapor-flow induced potentials may be ascribed to ions in the flowing vapors. This property of MWCNTs can advantage their application to nanoscale sensors, detectors and power cells.

THE THEORY OF CURRENT TRANSIENTS AT TUBULAR ELECTRODES IN A FLOWING FLUID

A theoretical equation is developed which describes the response of the current transients to a constant potential at tubular electrodes for a reversible electrode reaction in the flowing fluid.

THE VERIFICATION OF THE CURRENT TRANSIENT EQUATION AT TUBULAR ELECTRODES IN A FLOWING FLUID UNDER POTENTIAL STEP

The equation derived for the response of the current transients in the flowing fluid is verified experimentally.