3,302 research outputs found

    Global Solution to the Three-Dimensional Incompressible Flow of Liquid Crystals

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    The equations for the three-dimensional incompressible flow of liquid crystals are considered in a smooth bounded domain. The existence and uniqueness of the global strong solution with small initial data are established. It is also proved that when the strong solution exists, all the global weak solutions constructed in [16] must be equal to the unique strong solution

    HPM-14: A New Germanosilicate Zeolite with Interconnected Extra-Large Pores Plus Odd-Membered and Small Pores

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    HPM-14 is a new extra-large pore zeolite synthesized using imidazolium-based organic structure-directing agents (SDAs), fluoride anions, and germanium and silicon as tetrahedral components of the framework. Owing to the presence of stacking disorder, the structure elucidation of HPM-14 was challenging, and different techniques were necessary to clarify the details of the structure and to understand the nature of the disorder. The structure has been solved by three-dimensional electron-diffraction technique (3D ED) and consists of an intergrowth of two polymorphs possessing a three-dimensional channel system, including an extra-large pore opened through windows made up of sixteen tetrahedral atoms (16-membered ring, 16MR) as well as two additional sets of odd-membered (9MR) and small (8MR) pores. The intergrowth has been studied by scanning transmission electron microscopy (C-s-STEM) and powder X-ray diffraction simulations (DIFFaX), which show a large predominance of the monoclinic polymorph A

    Microwave Catalytic Conversion of SO2 and NOx over Cu/zeolite

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    Abstract: Microwave catalytic technology is a promising technology for flue gas treatment. Cu/zeolite was used as catalyst for microwave catalytic desulfurization and denitrification and for microwave catalytic reduction of SO2 and NOx with ammonium bicarbonate (NH4HCO3) as a reducing agent. Microwave catalytic desulfurization and denitrification efficiency achieved 76.1 and 81.8% separately. The reaction efficiency of microwave catalytic reduction of SO2 and NOx could be up to 99.8 and 92.8% respectively. The physico-chemical properties of Cu/zeolite catalysts were characterized by X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller measurements (BET), X-ray photoelectron spectrum analysis (XPS), scanning electron microscopy (SEM).The XPS results indicate that sulfide (SO42-), element sulfur (S0) and NH4+ species exist on the catalyst surface after the reaction. Microwave catalytic SO2 and NOx removal follows Langmuir — Hinshelwood(L-H) kinetics. Key words: Simultaneous desulfurization & denitrification; Microwave catalytic technology; Cu/zeolite; Characterizatio

    Ultrahigh Energy Nuclei in the Galactic Magnetic Field

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    Observations are consistent with a significant fraction of heavy nuclei in the cosmic ray flux above a few times 10^19 eV. Such nuclei can be deflected considerably in the Galactic magnetic field, with important implications for the search of their sources. We perform detailed simulations of heavy nuclei propagation within recent Galactic magnetic field models. While such models are not yet sufficiently constrained to predict deflection maps in detail, we find general features of the distribution of (de-) magnified flux from sources. Since in most theoretical models sources of heavy nuclei are located in the local large scale structure of galaxies, we show examples of images of several nearby galaxy clusters and of the supergalactic plane. Such general features may be useful to develop efficient methods for source reconstruction from observed ultrahigh energy cosmic ray arrival directions.Comment: 17 pages, 11 figures. Published in JCA

    Graphene oxide functionalized long period fiber grating for highly sensitive hemoglobin detection

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    We present graphene oxide (GO) nanosheets functionalized long period grating (LPG) for ultrasensitive hemoglobin sensing. The sensing mechanism relies on the measurement of LPG resonant intensity change induced by the adsorption of hemoglobin molecules onto GO, where GO as a bio-interface linkage provides the significant light-matter interaction between evanescent field and target molecules. The deposition technique based on chemical-bonding associated with physical-adsorption was developed to immobilize GO nanosheets on cylindrical fiber device. The surface morphology was characterized by scanning electron microscope, atomic force microscopy, and Raman spectroscopy. With relatively thicker GO coating, the refractive index (RI) sensitivity of GO-LPG was extremely enhanced and achieved −76.5 dB/RIU, −234.2 dB/RIU and +1580.5 dB/RIU for RI region of 1.33-1.38, 1.40-1.44 and 1.45-1.46, respectively. The GO-LPG was subsequently implemented as an optical biosensor to detect human hemoglobin giving a sensitivity of 1.9 dB/(mg/mL) and a detectable concentration of 0.05 mg/mL, which was far below the hemoglobin threshold value for anemia defined by World Health Organization. The proposed GO-LPG architecture can be further developed as an optical biosensing platform for anemia diagnostics and biomedical applications

    R-parity violation effect on the top-quark pair production at linear colliders

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    We investigate in detail the effects of the R-parity lepton number violation in the minimal supersymmetric standard model (MSSM) on the top-quark pair production via both ee+e^--e^+ and γγ\gamma-\gamma collision modes at the linear colliders. We find that with the present experimental constrained /R\rlap/{R} parameters, the effect from /R\rlap/{R} interactions on the processes e+ettˉe^+e^-\to t\bar{t} and e+eγγttˉe^+e^- \to \gamma\gamma \to t\bar{t} could be significant and may reach -30% and several percent, respectively. Our results show that the /R\rlap/{R} effects are sensitive to the c.m.s. energy and the relevant /R\rlap/{R} parameters. However, they are not sensitive to squark and slepton masses when mq~400GeVm_{\tilde{q}} \geq 400 GeV (or ml~300GeVm_{\tilde{l}} \geq 300 GeV) and are almost independent on the tanβ\tan\betaComment: Accepted by Phys.Rev.

    Model of a fluid at small and large length scales and the hydrophobic effect

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    We present a statistical field theory to describe large length scale effects induced by solutes in a cold and otherwise placid liquid. The theory divides space into a cubic grid of cells. The side length of each cell is of the order of the bulk correlation length of the bulk liquid. Large length scale states of the cells are specified with an Ising variable. Finer length scale effects are described with a Gaussian field, with mean and variance affected by both the large length scale field and by the constraints imposed by solutes. In the absence of solutes and corresponding constraints, integration over the Gaussian field yields an effective lattice gas Hamiltonian for the large length scale field. In the presence of solutes, the integration adds additional terms to this Hamiltonian. We identify these terms analytically. They can provoke large length scale effects, such as the formation of interfaces and depletion layers. We apply our theory to compute the reversible work to form a bubble in liquid water, as a function of the bubble radius. Comparison with molecular simulation results for the same function indicates that the theory is reasonably accurate. Importantly, simulating the large length scale field involves binary arithmetic only. It thus provides a computationally convenient scheme to incorporate explicit solvent dynamics and structure in simulation studies of large molecular assemblies
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