Pressure Gradient Force,Saffman Lift,and Magnus Lift on the Fiber-like Particle in Fluid

Flher-like particle suspensions are common in both na-ture and industry, but there is little work reported on it.The forces acting on the fiber - like particle in fluid arestudied in this paper, and the Magnus lift, Saffman lift,pressure gradient force, and then the dynamics modelhave been received. The numerical study of the simpleshear flow past the cylinders shows that the particles ’motion is controlled by the vortex.

TFT-LCD改善Particle Gap的研究

Particle Gap是TFT-LCD制程中常见的一种缺陷。以55UHD产品为例,Particle Gap发生率约为1.0%,对产品良率影响较大,为提升液晶屏品质和客户满意度,急需改善此不良。文章结合不良现象研究Particle Gap的主要异物模式,最终通过改善CF研磨失败异物、沙粒状异物和透明状异物这种模式达到整体Particle Gap降低的效果。首先利用流程图分析影响异物模式的关键步骤,然后通过鱼骨图、决策矩阵、假设检验验证找出影响异物模式的显著因素,最后通过合力促进法总结出显著因素的最佳改善方案,导入量产并文件标准化,可平行推广至55UHD以外的其它尺寸。改善结果表明:通过以上3种异物类型的改善,55UHD Particle Gap发生率降低至少30%,为公司带来了巨大且显著的硬性节省。

Obtaining vehicle parameters from bridge dynamic response:a combined semi-analytical and particle filtering approach

Dynamic load imposed on the bridge by mov- ing vehicle depends on several bridge-vehicle parameters with various uncertainties. In the present paper, particle filter technique based on conditional probability has been used to identify vehicle mass, suspension stiffness, and damping including tyre parameters from simulated bridge accelerations at different locations. A closed-form expres- sion is derived to generate independent response samples for the idealized bridge-vehicle coupled system consider- ing spatially non-homogeneous pavement unevenness. Thereafter, it is interfaced with the iterative process of particle filtering algorithm. The generated response sam- ples are contaminated by adding artificial noise in order to reflect field condition. The mean acceleration time history is utilized in particle filtering technique. The vehicle- imposed dynamic load is reconstructed with the identified parameters and compared with the simulated results. The present identification technique is examined in the presence of different levels of artificial noise with bridge response simulated at different locations. The effect of vehicle velocity, bridge surface roughness, and choice of prior probability density parameters on the efficiency of the method is discussed.

Introducing Ag in Ba_(0.9)La_(0.1)FeO_(3-δ):Combining cationic substitution with metal particle decoration

BaFeO_(3-δ)-derived perovskites are promising cathodes for intermediate temperature solid oxide fuel cells.The activity of these perovskites depends on the number of oxygen vacancies in their lattice,which can be tuned by cationic substitution.Our first-principle calculations show that Ag is a promising substitute for the Fe site,resulting in a reduced oxygen vacancy formation energy compared with the pristine BaFeO_(3-δ).Ag has limited solubility in perovskites,and its introduction generates an Ag metal secondary phase,which influences the cathode performances.In this work,we investigate the matter,using a Ba0:9La0:1Fe_(1-x)AgxO_(3-δ)series of materials as a case study.Acknowledging the limited solubility of Ag in Ba0:9La0:1Fe_(1-x)AgxO_(3-δ),we aim to distinguish the effects of Ag substitution from those of the Ag secondary phase.We observed that Ag substitution increases the number of oxygen vacancies,confirming our calculations,and facilitates the oxygen incorporation.However,Ag substitution lowers the number of holes,in this way reducing the electronic p-type conductivity.On the other hand,Ag metal positively affects the electronic conductivity and helps the redistribution of the electronic charge at the cathode-electrolyte interface.

Dynamic Weapon Target Assignment Based on Intuitionistic Fuzzy Entropy of Discrete Particle Swarm

Aiming at the problems of convergence-slow and convergence-free of Discrete Particle Swarm Optimization Algorithm(DPSO) in solving large scale or complicated discrete problem, this article proposes Intuitionistic Fuzzy Entropy of Discrete Particle Swarm Optimization(IFDPSO) and makes it applied to Dynamic Weapon Target Assignment(WTA). First, the strategy of choosing intuitionistic fuzzy parameters of particle swarm is defined, making intuitionistic fuzzy entropy as a basic parameter for measure and velocity mutation. Second, through analyzing the defects of DPSO, an adjusting parameter for balancing two cognition, velocity mutation mechanism and position mutation strategy are designed, and then two sets of improved and derivative algorithms for IFDPSO are put forward, which ensures the IFDPSO possibly search as much as possible sub-optimal positions and its neighborhood and the algorithm ability of searching global optimal value in solving large scale 0-1 knapsack problem is intensified. Third, focusing on the problem of WTA, some parameters including dynamic parameter for shifting firepower and constraints are designed to solve the problems of weapon target assignment. In addition, WTA Optimization Model with time and resource constraints is finally set up, which also intensifies the algorithm ability of searching global and local best value in the solution of WTA problem. Finally, the superiority of IFDPSO is proved by several simulation experiments. Particularly, IFDPSO, IFDPSO1~IFDPSO3 are respectively effective in solving large scale, medium scale or strict constraint problems such as 0-1 knapsack problem and WTA problem.

Solar Energetic Particle Event of 2005 January 20:Release Times and Possible Sources

Based on cosmic ray data obtained by neutron monitors at the Earth＇s surface, and data on near-relativistic electrons measured by the WIND satellite, as well as on solar X-ray and radio burst data, the solar energetic particle （SEP） event of 2005 January 20 is studied. The results show that this event is a mixed event where the flare is dominant in the acceleration of the SEPs, the interplanetary shock accelerates mainly solar protons with energies below 130 MeV, while the relativistic protons are only accelerated by the solar flare. The interplanetary shock had an obvious acceleration effect on relativistic electrons with energies greater than 2 MeV. It was found that the solar release time for the relativistic protons was about 06：41 UT, while that for the near-relativistic electrons was about 06：39 UT. The latter turned Out to be about 2 rain later than the onset time of the interplanetary type HI burst.

Investigation of the possible source for the solar energetic particle event on 2017 September 10

According to the solar proton data observed by Geostationary Operational Environmental Satellites （GOES）, ground-based neutron monitors on Earth and near-relativistic electron data measured by the ACE spacecraft, the onset times of protons with different energies and near-relativistic electrons have been estimated and compared with the time of solar soft and hard X-ray and radio burst data. The results show that first arriving relativistic and non-relativistic protons and electrons may have been accelerated by the concurrent flare. The results also suggest that release times of protons with different energies may be different, and the protons with lower energy may have been released earlier than those with higher energy. Some protons accelerated by concurrent flares may be further accelerated by the shock driven by the associated CME.

Numerical simulation of flow separation over a backward-facing step with high Reynolds number

Large eddy simulation (LES) explicitly calculates the large-scale vortex field and parameterizes the small-scale vortices.In this study,LES and κ-ε models were developed for a specific geometrical configuration of backward-facing step (BFS).The simulation results were validated with particle image velocimetry (PIV) measurements and direct numerical simulation (DNS).This LES simulation was carried out with a Reynolds number of 9000 in a pressurized water tunnel with an expansion ratio of 2.00.The results indicate that the LES model can reveal largescale vortex motion although with a larger grid-cell size.However,the LES model tends to overestimate the top wall separation and the Reynolds stress components for the BFS flow simulation without a sufficiently fine grid.Overall,LES is a potential tool for simulating separated flow controlled by large-scale vortices.

Measurements of suspended particulate matter with laser in-situ scattering and transmissometry in the Jiaozhou Bay in China

A laser in-situ scattering and transmissemetry probe （LISST - 100） was used to estimate the spatial variations of suspended particle （aggregate） distribution, volume concentration and beam attenuation in the Jiaozhou Bay, Qingdao, China on 18 July 2003. One study site was located at the mouth （Sta. J1 ）, with the other being within the inner bay （Sta. J2）. Measurements of total suspended matter （TSM） and chlorophyll fluorescence and sampling of bottom sediments were carried out simultaneously. On the basis of the field data, the in-situ particle effective density, settling velocity and flux, and particle projected surface area （PSA） were estimated. The results demonstrate that both profiles have similar particle size distributions from surface to bottom within the water columns. Mean particle diameters for Stas J1 and J2 are 38 - 74 and 1 - 20 μm, respectively, particles within these ranges dominate over the particulate components. Suspended particle volume concentrations increase with water depth, with spikes near the bottom. At Sta. J1, the mean size of bottom sediments and those of suspended particles at 10.8 m below the water surface are almost the same, as well as their size distributions. This observation suggests that a special affinity exists between bottom sediment and suspended particles. In addition, the estimates show that the effective density, settling velocity and flux are higher in the innet bay. Beam attenuation coefficient correlates well with the volume concentration, positively. It is inferred that the optical scattering was mostly caused by 1 - 250 μm components, among which the particles finer than 20 μm dominate the beam attenuation. The PSA appears a proxy for the leaving reflectance estimation.

The Influence of Ion-Acoustic Turbulence on the Electron Acceleration in the Reconnecting Current Sheet

Through solving the single electron equation of motion and the Fokker Planck equation including the terms of electric field strength and ion-acoustic turbulence, we study the influence of the ion-acoustic wave on the electron acceleration in turbulent reconnecting current sheets. It is shown that the ion-acoustic turbulence which causes plasma heating rather than particle acceleration should be considered. With typical parameter values, the acceleration time scale is around the order of 10-6 s, the accelerated electrons may have approximately a power-law distribution in the energy range 20-100 keV and the spectral index is about 3-10, which is basically consistent with the observed hard X-ray spectra in solar flares.

The Role of Nuclei-Nuclei Interactions in the Production of Gamma-ray Lines in Solar Flares

Dramatic extensions of experimental possibilities (spacecraft RHESSI, CORONAS-F and others) in solar gamma-ray astronomy call for urgent, detailed theoretical consideration of a set of physical problems of solar activity and solar-terrestrial relationships that earlier may have only been outlined. Here we undertake a theoretical analysis of issues related to the production of gamma-radiation in the processes of interactions of energetic (accelerated) heavy and middle nuclei with the nuclei of the solar atmosphere (the so-called i-j interactions). We also make an estimate of the contribution of these interactions to the formation of nuclear and isotopic abundances of the solar atmosphere in the range of light and rare elements. The analysis is carried out for solar flares in the wide range of their intensities. We compare our theoretical estimates with RHESSI observations for the flare of 2002 July 23. It was shown that the 24Mg gamma-ray emission in this event was produced by the newly generated Mg nuclei. With a high probability, the gamma-ray line emission of 28Si nuclei from this flare was generated by the same processes.

Solar Impulsive Hard X-Ray Emission and Two-Stage Electron Acceleration

Heating and acceleration of electrons in solar impulsive hard X-ray （HXR） flares are studied according to the two-stage acceleration model developed by Zhang for solar ^3Herich events. It is shown that electrostatic H-cyclotron waves can be excited at a parallel phase velocity less than about the electron thermal velocity and thus can significantly heat the electrons （up to 40 MK） through landau resonance. The preheated electrons with velocities above a threshold are further accelerated to high energies in the flare-acceleration process. The flareproduced electron spectrum is obtained and shown to be thermal at low energies and power law at high energies. In the non-thermal energy range, the spectrum can be double power law if the spectral power index is energy dependent or related. The electron energy spectrum obtained by this study agrees quantitatively with the result derived from the Reuven Ramaty High Energy Solar Spectroscopic Imager （RHESSI） HXR observations in the flare of 2002 July 23. The total flux and energy flux of electrons accelerated in the solar flare also agree with the measurements.

Possible Contribution of Mature γ-ray Pulsars to Cosmic-ray Positrons

We restudy the possible contribution of mature gamma-ray pulsars to cosmic ray positrons based on the new version of outer gap model. In this model, the inclination angle and average properties of the outer gap are taken into account, and more mature pulsars can have the outer gap and emit high energy photons. Half of the primary particles in the outer gaps will flow back toward the star surface and emit synchrotron photons, which can produce electron/positron pairs by the cascade of pair production. Some of these pairs will escape from the light cylinder and be accelerated to relativistic energies in the pulsar wind driven by low-frequency electromagnetic waves. Using a Monte Carlo method, we obtain a sample of mature gamma-ray pulsars and then calculate the production of the positrons from these pulsars. The observed excess of cosmic positrons can be well explained by this model.

Synthesis and Characterization of Polystyrene/Nanosilica Organic-Inorganic Hybrid

A polystyrene（PS）/nanosilica organic-inorganic hybrid material was prepared from styrene monomer and commercial aqueous silica sol containing large amounts of Si-OH by means of emulsion polymerization. The nanosilica sol was modified by the addition of the reactive coupling agent methacrylexy propyltrimethoxysilane （ MPS）, and the resulting latex particles were protected by surfactants such as sodium dodecyl sulphonate（ SDS）, hydroxypropyl methyl cellulose （ HMPC）, and poly （vinylpyrrolidone） （PVP）. The effects of the type of surfactant, the amount of surfactant, and the coupling agent on the shape and stability of the resulting latex particles were investigated. The TEM observation indicates that among SDS, HMPC, and PVP, SDS is the best surfactant. When the content of SDS is 0. 5% and the amount of MPS is 7% in the system, the latex with obvious core-shell structure could be obtained. The average diameters of the monodispersed particles range from 182 to 278 nm, and the average number of silica beads for each composite are 1325 and 4409, respectively. The FrIR analysis shows that PS was chemically linked to silica through MPS. The thermal gravimetric analysis shows that when there is a higher silica content, the hybrid composites have a better heat resistance.

Numerical Analysis of the Behavior of A New Aeronautical Alloy (Ti555-03) Under the Effect of A High-Speed Water Jet

In this paper, we present a numerical simulation of a water jet impacting a new aeronautical material Ti555-03 plate.The Computational Fluid Dynamics(CFD) behavior of the jet is investigated using a FV(Finite Volume) method.The Fluid–Structure Interaction(FSI) is studied using a coupled SPH(Smoothed Particle Hydrodynamics)-FE(Finite Element) method. The jets hit the metal sheet with an initial velocity 500 m/s. Two configurations which differ from each other by the position(angle of inclination) of the plate relatively to the axis of revolution of the jet inlet are investigated in this study. The objective of this study is to predict the impact of the fluid produced at high pressure and high speed especially at the first moment of impact. Numerical simulations are carried out under ABAQUS. We have shown in this study that the inclination of the titanium alloy plate by 45° stimulates the phenomenon of recirculation of water. This affects the velocity profile, turbulence and boundary layers in the impact zone. The stagnation zone and the phenomenon of water recirculation are strongly influenced by the slope of the plate which gives a pressure gradient and displacement very important between the two configurations. Fluctuations of physical variables(displacement and pressure) prove the need for a noise and vibratory study. These predictions will subsequently be used for the modeling of the problem of an orthogonal cut in a high-speed machining process assisted by high-pressure water jet.

An Annular Gap Acceleration Model for γ-ray Emission of Pulsars

If the binding energy of the pulsar＇s surface is not so high （the case of a neutron star）, both negative and positive charges will flow out freely from the surface of the star. An annular free flow model for 7-ray emission of pulsars is suggested. It is emphasized that： （1） Two kinds of acceleration regions （annular and core） need to be taken into account. The annular acceleration region is defined by the magnetic field lines that cross the null charge surface within the light cylinder. （2） If the potential drop in the annular region of a pulsar is high enough （normally the case for young pulsars）, charges in both the annular and the core regions could be accelerated and produce primary gamma-rays. Secondary pairs are generated in both regions and stream outwards to power the broadband radiations. （3） The potential drop grows more rapidly in the annular region than in the core region. The annular acceleration process is a key process for producing the observed wide emission beams. （4） The advantages of both the polar cap and outer gap models are retained in this model. The geometric properties of the 7-ray emission from the annular flow are analogous to that pre-sented in a previous work by Qiao et al., which match the observations well. （5） Since charges with different signs leave the pulsar through the annular and the core regions respectively, the current closure problem can be partially solved.

Second Thoughts about the <i>τ-θ</i>Puzzle

The new parity value of π0 was determined according to the hypothesis of conservation of particle number. The theo-retical pentaquark proton’s parity value was also determined, and it was found that the conservation of parity is account nicely for the τ-θ puzzle.

On the limitations of linear beams for the problems of moving mass-beam interaction using a meshfree method

This paper deals with the capabilities of linear and nonlinear beam theories in predicting the dynamic response of an elastically supported thin beam traversed by a moving mass. To this end, the discrete equations of motion are developed based on Lagrange＇s equations via reproducing kernel particle method （RKPM）. For a particular case of a simply supported beam, Galerkin method is also employed to verify the results obtained by RKPM, and a reasonably good agreement is achieved. Variations of the maximum dynamic deflection and bending moment associated with the linear and nonlinear beam theories are investigated in terms of moving mass weight and velocity for various beam boundary conditions. It is demonstrated that for majority of the moving mass velocities, the differences between the results of linear and nonlinear analyses become remarkable as the moving mass weight increases, particularly for high levels of moving mass velocity. Except for the cantilever beam, the nonlinear beam theory predicts higher possibility of moving mass separation from the base beam compared to the linear one. Furthermore, the accuracy levels of the linear beam theory are determined for thin beams under large deflections and small rotations as a function of moving mass weight and velocity in various boundary conditions.

Air Quality Regarding to TSP in Six Cities of Sonora,Mexico,a Criticism to the NOM-025-SSA1-1993 and a Proposed Criterion for Its Non-Compliance

In the present study, the air quality is assessed for the year 2010 regarding to the Total Suspended Particles (TSP) for six cities of Sonora, Mexico, representing the first regional study in Sonora in air quality. The assessment used performance indicators and indicators of compliance with the regulations. It is established that in all the cities the maximum limit value of daily concentration of 210 μg/m3 is exceeded, being the percentage of days above the rule of 30%, 78%, 76%, 6%, 3% and 62% for Agua Prieta, Nogales, Puerto Penasco, Hermosillo, Guaymas and Obregón respectively, classifying these days with poor air quality. According to the annualized index used, the air quality was not satisfactory for the period of study in the six cities. Nogales and Puerto Penasco presented the most adverse conditions of air quality with annual average values of TSP of 363 and 345 μg/m3 and maximum daily of 1047 and 1239 μg/m3 (498% and 590% above the norm) respectively. The requirements of coverage that establishes the Mexican Official Standard NOM-025-SSA1-1993 (SSA, 2005) are questioned for its compliance, proposing in this paper a criterion of non-compliance by prioritizing the protection of health and the precautionary principle. It is recommended to implement air quality management programs (PROAIRE) in these cities.

Finite Element Simulation of the Polymeric Liquid Flow in Coat-hanger Die

A three - dimenslonal finite element model is developed to deal with the polymeric liquid flow in coat - hanger die. This model is used to predict the flow behavior of the 2％ CMC/watsr solution in the coat - hanger die with linearly taper manifolds and its validity is experimentally verified quantitatively and qualitatively by using Laser Doppler Velocimetry and Particle Image Velocimetry respectively.