Experimental Study of the Distribution of Au and Cu in Aqueous Vapor Phase at High Temperatures and Its Role on Ore-forming Transportation

This study focuses on experiments of Au and Cu dissolved in vapor phase in hydrothermal fluids. Experiments prove that Au and Cu can re-distribute in vapor phase and liquid phase during separation of Au- and Cu-bearing supercritical fluids to vapor and liquid phases. These experimental results can illustrate some ore geneses, where boiling phenomena of ore fluids were found. Au- and Cubearing NaHCO3-HCl solutions were heated up to more than 350℃ in the main vessel, and then passed through a phase separator in a temperature range from 250℃ to 300℃, separated into vapor and liquid phases. We collected and analyzed the liquid and vapor samples separately, and found that Au and Cu dissolved and distributed in vapor phase. In some cases, the concentrations of Au and Cu in vapor are higher than those in liquid phase. Those experiments are used to interpret field observations of fluid inclusion data of some Au and Cu deposits, and demonstrate that some Au and Cu ore deposits are derived from metals transportation in vapor phase.

Bionic Design and Finite Element Analysis of Elbow in Ice Transportation Cooling System

With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical problem; typically flowresistance occurs in the elbow. In the present study, according to the analysis of the surface morphology of fish scale, abiomimetic functional surface structure for the interior wall of elbow is designed. Based on the theory of liquid-solid two phaseflow, a CFD numerical simulation of ice-water mixture flowing through the elbow is carried out using finite element method.Conventional experiments of pressure drop and flow resistance for both bionic and common elbows are conducted to test theeffect of the bionic elbow on flow resistance reduction. It is found that with the increase in the ice mass fraction in the ice-watermixture, the effect of bionic elbow on resistance reduction becomes more obvious.

Optical properties of ZnO and Mn-doped ZnO nanocrystals by vapor phase transport processes

In this paper we investigated the optical properties of ZnO and Mn doped ZnO nanocrystals that were fabricated by a vapor phase transport growth process, using zinc acetate dihydrate with or without Mn in a constant O2/Ar mixture gas flowing through the furnace at 400600℃, respectively. The as grown ZnO nanocrystals are homogeneous with a mean size of 19 nm observed by scanning electron microscope（SEM）. The optical characteristics were analyzed by absorption spectra and photoluminescence（PL） spectra at room-temperature. For ZnO nanocrystals, a strong and predominant UV emission peaked at 377 nm was found in the PL spectra. For Mn doped ZnO nanocrystals, in addition to the strong UV emission, a strong blue emission peaked at 435 nm was observed as well. By doping Mn ions, the major UV emission shifts from 377 nm to 408 nm, showing that Mn ions were not only incorporated into ZnO Ncs, but also introduced an impurity level in the bandgap. Moreover, with the concentration of Mn increasing, the relative intensities of the two emissions change largely, and the photoluminescence mechanism of them is discussed.

Coupled Model of Two-phase Debris Flow,Sediment Transport and Morphological Evolution

The volume fraction of the solid and liquid phase of debris flows, which evolves simultaneously across terrains, largely determines the dynamic property of debris flows. The entrainment process significantly influences the amplitude of the volume fraction. In this paper, we present a depth-averaged two-phase debris-flow model describing the simultaneous evolution of the phase velocity and depth, the solid and fluid volume fractions and the bed morphological evolution. The model employs the Mohr–Coulomb plasticity for the solid stress, and the fluid stress is modeled as a Newtonian viscous stress. The interfacial momentum transfer includes viscous drag and buoyancy. A new extended entrainment rate formula that satisfies the boundary momentum jump condition （Iverson and Ouyang, 2015） is presented. In this formula, the basal traction stress is a function of the solid volume fraction and can take advantage of both the Coulomb and velocity-dependent friction models. A finite volume method using Roe’s Riemann approximation is suggested to solve the equations. Three computational cases are conducted and compared with experiments or previous results. The results show that the current computational model and framework are robust and suitable for capturing the characteristics of debris flows.

Characteristics of ZnO Particles Prepared by Au-catalyzed Phase Transport Technique

ZnO particles were prepared by Au-catalyzed vapor phase transport method on silicon substrate. Scanning electron microscopy（SEM） images show many ZnO particles were formed on the sample surface. They grew up layer by layer along the c-axis, which was confirmed by the results of X-ray diffraction（XRD）. The morphology of ZnO particles is close to hemisphere and its formation process could be seen from the SEM image. The room temperature photoluminescence（PL） measurement revealed a narrow UV emission peak at 3.27 eV and a broad green emission peak at 2.45 eV, which was caused by the near-band-edge and deep-level emissions.

Phase Separation and Transport Behavior in La_(0.67-x)Sm_xSr_(0.33)MnO_3 System

The magnetic behavior and the transport behavior of La0.67-x Smx Sr0.33 MnO3 （x = 0. 00, 0. 10, 0. 20, 0. 30, 0. 40, 0. 50 and 0. 60 ） systems were studied through measuring the M-T curves, electron spin resonance （ ESR ） curves and ρ-T curves. The samples exhibit a long-range ferromagnetic order when x = 0. 00, 0. 10, a cluster-spin glass state when x = 0. 20 and 0. 30, and an anti-ferromagnetic state at low temperatures when x = 0. 40, 0. 50 and 0. 60. The samples of x = 0. 30 and 0.40 show phase separation at temperatures above Te. The transport behavior of the sample of x = 0. 60 becomes abnormal when the doping is high, and an insulator-metal transition occurs near To and then a metal-insulator transition occurs, which rarely appears in an ABO3 structure. It is concluded that the magnetic and electric behavior changes of the systems depend on the extra magnetism and lattice distortion effect induced by Sm doping.

Phase transition and charge transport through a triple dot device beyond the Kondo regime

Semiconductor quantum dot structure provides a promising basis for quantum information processing, within which to reveal the quantum phase and charge transport is one of the most important issues. In this paper, by means of the numerical renormalization group technique, we study the quantum phase transition and the charge transport for a parallel triple dot device in the strongly correlated limit, focusing on the effect of inter-dot hopping t beyond the Kondo regime. We find the quantum behaviors depend closely on the initial electron number on the dots, and the present model may map to single,double, and side-coupled impurity models in different parameter spaces. An orbital spin-1/2 Kondo effect between the conduction leads and the bonding orbital, and several magnetic-frustration phases are demonstrated when t is adjusted to different regimes. To understand these phenomena, a canonical transformation of the energy levels is given, and important physical quantities with respect to increasing t and necessary theoretical discussions are shown.

Gluon Transport Properties in the Region of Coexistence of Both Hadronic and QGP Phases

The transport properties of gluon in color space in a system of coexistence of both hadronic and QGP phases are investigated from the quantum transport equation of gluon.

In—Phase Resonances with Generic Transmission Zeros and Eigenvectors of Hamiltonian in Models of Single Channel Transport

We investigate the phase coherent transport in a single channel system. The theory that the transmission zeros lead to abrupt phase change and in-phase resonances is confirmed numerically in two tight-binding models. After calculating the eigenvalues and eigenvectors of the Hamiltonians we also confirmed that the same symmetry of the eigenvectors also leads to the abrupt phase change and in-phase resonances that equal the transmission zero.

Predicting Net Cross-Shore Total Load Transport: A Phase-Averaging, Quasi-Steady Approach Incorporating Undertow Contribution

Wave shapes that induce velocity skewness and acceleration asymmetry are usually responsible for onshore sediment transport, whereas undertow and bottom slope effect normally contribute to offshore sediment transport. By incorporating these counteracting driving forces in a phase-averaged manner, the theoretically-based quasi-steady formula of Wang （2007） is modified to predict the magnitude and direction of net cross-shore total load transport under the coaction of wave and current. The predictions show an excellent agreement with the measurement data on medium and fine sand collected by Dohmen-Janssen and Hanes （2002） and Schretlen （2012） in a full-scale wave flume at the Coastal Research Centre in Hannover, Germany. The modified formula can predict the net onshore transport of fine sand in sheet flows. In particular, it can predict the net offshore transport of medium sand in rippled beds through enlarged bed roughness, as well as the net offshore transport of fine-to-coarse sand in sheet flows with the aid of a new criterion to judge the occurrence of net offshore transport.

Nonlinear Transport for Beam Phase Space of the High Curent Injector

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Tb(III) Transport in Dispersion Supported Liquid Membrane System with D2EHPA as Carrier in Kerosene

The transport of Tb（III） in dispersion supported liquid membrane（DSLM） with polyvinylidene fluoride membrane（PVDF） as the support and dispersion solution including HCl solution as the stripping solution and di（2-ethylhexyl） phosphoric acid（D2EHPA） dissolved in kerosene as the membrane solution, has been studied. The effects of pH value, initial concentration of Tb（III） and different ionic strength in the feed phase, volume ratio of membrane solution to stripping solution, concentration of HCl solution, concentration of carrier, different stripping agents in the dispersion phase on the transport of Tb（III） have also been investigated, respectively. As a result, the optimum transport conditions of Tb（III） were obtained, i.e., the concentration of HCl solution was 4.0 mol/L, the concentration of D2EHPA was 0.16 mol/L, the volume ratio of membrane solution to stripping solution was 30：30 in the dispersion phase and pH value was 4.5 in the feed phase. Ionic strength had no obvious effect on the transport of Tb（III）. Under the optimum conditions, the transport percentage of Tb（III） was up to 96.1% in a transport time of 35 min when the initial concentration of Tb（IIl） was 1.0× 10 -4 mol/L. The diffusion coefficient of Tb（III） in the membrane and the thickness of diffusion layer between feed phase and membrane phase were obtained and the values were 1.82×10 -8 m2/s and 5.61 um, respectively. The calculated results were in good agreement with the literature data.

Mechanism of Phase Lag Between Current Speed and Suspended Sediment: Combined Effect of Erosion, Deposition, and Advection

To retrieve and explain the phase lag between current speed and suspended sediment concentration(SSC), erosion, deposition, and advection were isolated as primary processes of sediment movement in a three-dimensional model. The response time was proved to be one of the reasons for the phase lag, as time is needed for suspension to diffuse from bottom to surface. A fitted Shields diagram was introduced into the model to reflect the relationship between SSC and shear stress, between shear stress and critical shear stress, as well as between SSC and critical shear stress for erosion. It takes some time for shear stress to increase to the critical value after high or low tide, and this was proved to be an important contributor to the phase lag. Overall, the variation of vertically integrated SSC is influenced by erosion mass flux, deposition mass flux, and advection flux. The phase pattern of erosion mass flux is consistent with the pattern of current if there was no wave action. However, phase difference is produced by the influence of deposition mass flux and advection. In this study, SSC peak/trough mostly occurred near the moment erosion mass flux approximately equaled deposition mass flux and would be impacted by advection. The time required for instantaneous variation of suspension to get to 0 after current peak/trough represents the phase lag between current speed and SSC.

Flow, Transport and Biodegradation of Toluene During Bioventing

Bioventing is conducted on one-dimensional soil columns. A numerical model is developed for simulating the mass exchange, advective and dispersive transport and biodegradation of toluene. The model parameters are estimated independently through laboratory batch experiments, or from literature. Simulations are found to provide reasonable agreement with experimental data. Experimental results show that toluene removal due to biodegradation is more important at the later stage. The total cleanup time when NAPL (non-aqueous phase liquid) phase exists was twice more than that without NAPL. Sensitivity analysis of parameters suggests that model predictions are mainly dependent on mass transfer coefficient and microbial parameters, such as the half-saturation coefficient and maximum specific substrate utilization rate.

Fast and extensive intercalation chemistry in Wadsley-Roth phase based high-capacity electrodes

Wadsley-Roth (W-R) structured oxides featured with wide channels represent one of the most promising material families showing compelling rate performance for lithium-ion batteries.Herein,we report an indepth study on the fast and extensive intercalation chemistry of phosphorus stabilized W-R phase PNb_(9)O_(25) and its application in high energy and fast-charging devices.We explore the intercalation geometry of PNb_(9)O_(25) and identify two geometrical types of stable insertion sites with the total amount much higher than conventional intercalation-type electrodes.We reveal the ion transportation kinetics that the Li ions initially diffuse along the open type Ⅲ channels and then penetrate to edge sites with low kinetic barriers.During the lithiation,no remarkable phase transition is detected with nearly intact host phosphorous niobium oxide backbone.Therefore,the oxide framework of PNb_(9)O_(25) keeps almost unchanged with all the fast diffusion channels and insertion cavities well-maintained upon cycling,which accomplishes the unconventional electrochemical performance of W-R structured electrodes.

Evaluation of Energy Band Gap, Thermal Conductivity, Phase Transition Temperature and Elastic Response of PS/CdS Semiconducting Optical Nanocomposite

Thick film of Polystyrene (PS)/CdS semiconducting optical nanocomposite has been synthesized by dispersing nanofiller particles of CdS in PS matrix. The nanostructure of the CdS particles has been ascertained through X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Small angle x-ray scattering analysis has been performed in order to ascertain nanocomposite character of the PS/CdS sample. Scanning Electron Microscopy (SEM) analyses of these samples have been carried out to establish the surface morphology. Optical Absorption Spectroscopy is used to measure the energy band gap of PS/CdS nanocomposite by using Tauc relation whereas Transient Plane Source Technique is used for the determination of thermal conductivity of the prepared samples. The phase transition temperature and elastic response of the prepared samples have been ascertained through Dynamic Mechanical Analyzer (DMA). This study reveals that the thermal conductivity, Young’s modulus and the toughness of the material are greatly influenced by the existence of interfacial energetic interaction between dispersed CdS nanofiller particles and matrix of PS.

Charge carrier dynamics in different crystal phases of CH_(3)NH_(3)PbI_(3)perovskite

Despite that organic-inorganic lead halide perovskites have attracted enormous scientific attention for energy conversion applications over the recent years,the influence of temperature and the type of the employed hole transport layer(HTL)on the charge carrier dynamics and recombination processes in perovskite photovoltaic devices is still largely unexplored.In particular,significant knowledge is missing on how these crucial parameters for radiative and non-radiative recombinations,as well as for efficient charge extraction vary among different perovskite crystalline phases that are induced by temperature variation.Herein,we perform micro photoluminescence(pPL)and ultrafast time resolved transient absorption spectroscopy(TAS)in Glass/Perovskite and two dierent Glass/ITO/HTL/Perovskite configurations at temperatures below room temperature,in order to probe the charge carrier dynamics of different perovskite crystalline phases,while considering also the effect of the employed HTL polymer.Namely,CH_(3)NH_(3)Pbb films were deposited on Glass,PEDOT:PSS and PTAA polymers,and the developed Glass/CH_(3)NH_(3)PbI_(3)and Glass/ITO/HTL/CH_(3)NH_(3)PbI_(3)architectures were studied from 85 K up to 215 K in order to explore the charge extraction dynamics of the CH_(3)NH_(3)PbI_(3)orthorhombic and tetragonal crystalline phases.It is observed an unusual blueshift of the bandgap with temperature and the dual emission at temperature below of 100 K and also,that the charge carrier dynamics,as expressed by hole injection times and free carrier recombination rates,are strongly depended on the actual pervoskite crystal phase,as well as,from the selected hole transport material.

Electric transport properties and temperature stability of magnetoresistance of composite system between La_(8/9)Sr_(1/45)Na_(4/45)MnO_3 and Sb_2O_3

The samples ofLa8/9Sr1/45Na4/45MnO3 （LSNMO）/x/2（Sb2O3） were prepared by the solid-state reaction method. The electric transport properties and the temperature stabil-ity of magnetoresistance （MR） of the samples were studied through the measurements of X-ray diffraction patterns, resistivity-temperature （ρ-T） curves, mass magnetization-temperature （σ-T） curves, and magnetoresistance-temper-ature （MR-T） curves. The results indicate that the p-Tcurves of the original material LSNMO show two peaks, and the phenomenon of two peaks of ρ-T curves disappears for the composite samples, which can be explained by a competition between surface-phase resistivity induced by boundary-dependent scattering and body-phase resistivity induced by paramagnetism-ferromagnetism transition. For all the sam-ples in the low temperature range, MR increases continu-ously with the decrease of temperature, which shows a characteristic of low-field magnetoresistance. However, MR basically keeps the same in the high temperature range. The paramagnetism-ferromagnetism transition is observed in the high temperature range due to a composite between perov-skite manganite and insulator, which can enhance the tem-perature of MR appearance in the high temperature range and make it to appear near room temperature. For the sample with x = 0.12, MR remains constant at the value of 7.5 % in the temperature range of 300-260 K, which achieves a tem-perature stability of MR near room temperature. In addition,for the sample with x = 0.16, MR is above 6.8 % in the high temperature range of 318-252 K （△T = 66 K）. MR almost remains constant in this temperature range, which favors the practical application of MR.

Geometric phase of an open double-quantum-dot system detected by a quantum point contact

We study theoretically the geometric phase of a double-quantum-dot(DQD) system measured by a quantum point contact(QPC) in the pure dephasing and dissipative environments, respectively. The results show that in these two environments, the coupling strength between the quantum dots has an enhanced impact on the geometric phase during a quasiperiod. This is due to the fact that the expansion of the width of the tunneling channel connecting the two quantum dots accelerates the oscillations of the electron between the quantum dots and makes the length of the evolution path longer.In addition, there is a notable near-zero region in the geometric phase because the stronger coupling between the system and the QPC freezes the electron in one quantum dot and the solid angle enclosed by the evolution path is approximately zero,which is associated with the quantum Zeno effect. For the pure dephasing environment, the geometric phase is suppressed as the dephasing rate increases which is caused only by the phase damping of the system. In the dissipative environment,the geometric phase is reduced with the increase of the relaxation rate which results from both the energy dissipation and phase damping of the system. Our results are helpful for using the geometric phase to construct the fault-tolerant quantum devices based on quantum dot systems in quantum information.

Solution of the finite slab criticality problem using an alternative phase function with the second kind of Chebyshev polynomials

The critical size of a finite homogenous slab is investigated for one-speed neutrons using the alternative phase function(AG, Anli-Gungor) in place of the scattering function of the transport equation. First of all, the neutron angular flux expanded in terms of the Chebyshev polynomials of second kind(UN approximation) together with the AG phase function is applied to the transport equation to obtain a criticality condition for the system.Then, using various values of the scattering parameters, the numerical results for the critical half-thickness of the slab are calculated and they are tabulated in the tables together with the ones obtained from the conventional spherical harmonic(PN) method for comparison. They can be said to be in good accordance with each other.