Extending the Propagation Distance of a Silver Nanowire Plasmonic Waveguide with a Dielectric Multilayer Substrate

Chemical synthesized silver nanowires have been proved to be the efficient architecture for Plasmonic waveguides, but the high propagation loss prevents their widely applications. Here, we demonstrate that the propagation distance of the plasmons along the Ag NW can be extended if the Ag NW was placed on a dielectric multilayer substrate containing a photonic band gap, but not placed on a commonly used glass substrate. The propagation distance at 630 nm wavelength can reach 16 um even that the Ag NW is as thin as 90 nm in diameter. Experimental and simulation results further show that the polarization of this propagating plasmon mode was nearly parallel to the surface of the dielectric multilayer, so it was excited by a transverse-electric polarized Bloch surface wave propagating along a polymer nanowire with diameter at only about 170 nm on the same dielectric multilayer. Numerical simulations were also carried out and consistent with the experiment results. Our work provides a platform to extend the propagation distance of plasmonic waveguide and also for the integration between photonic and plasmonic waveguides on the nanometre scale.Comment: 5 pages, 4 figure

A novel model for synthesizing parallel I/O workloads in scientific applications

Abstract — One of the challenging issues in performance eval-uation of parallel storage systems through synthetic-trace-driven simulation is to accurately characterize the I/O demands of data-intensive scientific applications. This paper analyzes several I/O traces collected from different distributed systems and concludes that correlations in parallel I/O inter-arrival times are inconsistent, either with little correlation or with evident and abundant correlations. Thus conventional Poisson or Markov arrival processes are inappropriate to model I/O arrivals in some applications. Instead, a new and generic model based on the α-stable process is proposed and validated in this paper to accurately model parallel I/O burstiness in both workloads with little and strong correlations. This model can be used to generate reliable synthetic I/O sequences in simulation studies. Experimental results presented in this paper show that this model can capture the complex I/O behaviors of real storage systems more accurately and faithfully than conventional models, particularly for the burstiness characteristics in the parallel I/O workloads. I

Supra-molecular assembly of aromatic proton sponges to direct the crystallization of extra-large-pore zeotypes

The combination of different experimental techniques, such as solid C-13 and H-1 magic-angle spinning NMR spectroscopy, fluorescence spectroscopy and powder X-ray diffraction, together with theoretical calculations allows the determination of the unique structure directing the role of the bulky aromatic proton sponge 1,8-bis(dimethylamino)naphthalene (DMAN) towards the extra-large-pore ITQ-51 zeolite through supra-molecular assemblies of those organic molecules.This work has been supported by the Spanish Government through Consolider Ingenio 2010-Multicat, the 'Severo Ochoa Programme' (SEV 2012-0267), MAT2012-37160; UPV through PAID-06-11 (no. 1952); the Swedish Research Council (VR) and the Swedish Governmental Agency for Innovation Systems (VINNOVA).Martínez Franco, R.; Sun, J.; Sastre Navarro, GI.; Yun, Y.; Zou, X.; Moliner Marin, M.; Corma Canós, A. (2014). Supra-molecular assembly of aromatic proton sponges to direct the crystallization of extra-large-pore zeotypes. Proceedings of the Royal Society of London. Series A, Mathematical and physical sciences. 470:1-13. https://doi.org/10.1098/rspa.2014.0107S113470Moliner, M., Rey, F., & Corma, A. (2013). Towards the Rational Design of Efficient Organic Structure-Directing Agents for Zeolite Synthesis. Angewandte Chemie International Edition, 52(52), 13880-13889. doi:10.1002/anie.201304713Freyhardt, C. C., Tsapatsis, M., Lobo, R. F., Balkus, K. J., & Davis, M. E. (1996). A high-silica zeolite with a 14-tetrahedral-atom pore opening. Nature, 381(6580), 295-298. doi:10.1038/381295a0Wagner, P., Yoshikawa, M., Tsuji, K., Davis, M. E., Wagner, P., Lovallo, M., & Taspatsis, M. (1997). CIT-5: a high-silica zeolite with 14-ring pores. Chemical Communications, (22), 2179-2180. doi:10.1039/a704774fBurton, A., Elomari, S., Chen, C.-Y., Medrud, R. C., Chan, I. Y., Bull, L. M., … Vittoratos, E. S. (2003). SSZ-53 and SSZ-59: Two Novel Extra-Large Pore Zeolites. Chemistry - A European Journal, 9(23), 5737-5748. doi:10.1002/chem.200305238Corma, A., Díaz-Cabañas, M. J., Rey, F., Nicolopoulus, S., & Boulahya, K. (2004). ITQ-15: The first ultralarge pore zeolite with a bi-directional pore system formed by intersecting 14- and 12-ring channels, and its catalytic implications. Chem. Commun., (12), 1356-1357. doi:10.1039/b406572gSun, J., Bonneau, C., Cantín, Á., Corma, A., Díaz-Cabañas, M. J., Moliner, M., … Zou, X. (2009). The ITQ-37 mesoporous chiral zeolite. Nature, 458(7242), 1154-1157. doi:10.1038/nature07957Jiang, J., Jorda, J. L., Yu, J., Baumes, L. A., Mugnaioli, E., Diaz-Cabanas, M. J., … Corma, A. (2011). Synthesis and Structure Determination of the Hierarchical Meso-Microporous Zeolite ITQ-43. Science, 333(6046), 1131-1134. doi:10.1126/science.1208652Kubota, Y., Helmkamp, M. M., Zones, S. I., & Davis, M. E. (1996). Properties of organic cations that lead to the structure-direction of high-silica molecular sieves. Microporous Materials, 6(4), 213-229. doi:10.1016/0927-6513(96)00002-8Corma, A., Rey, F., Rius, J., Sabater, M. J., & Valencia, S. (2004). Supramolecular self-assembled molecules as organic directing agent for synthesis of zeolites. Nature, 431(7006), 287-290. doi:10.1038/nature02909Gómez-Hortigüela, L., López-Arbeloa, F., Corà, F., & Pérez-Pariente, J. (2008). Supramolecular Chemistry in the Structure Direction of Microporous Materials from Aromatic Structure-Directing Agents. Journal of the American Chemical Society, 130(40), 13274-13284. doi:10.1021/ja8023725Gómez-Hortigüela, L., Hamad, S., López-Arbeloa, F., Pinar, A. B., Pérez-Pariente, J., & Corà, F. (2009). Molecular Insights into the Self-Aggregation of Aromatic Molecules in the Synthesis of Nanoporous Aluminophosphates: A Multilevel Approach. Journal of the American Chemical Society, 131(45), 16509-16524. doi:10.1021/ja906105xStaab, H. A., & Saupe, T. (1988). ?Proton Sponges? and the Geometry of Hydrogen Bonds: Aromatic Nitrogen Bases with Exceptional Basicities. Angewandte Chemie International Edition in English, 27(7), 865-879. doi:10.1002/anie.198808653Leslie, M., & Gillan, N. J. (1985). The energy and elastic dipole tensor of defects in ionic crystals calculated by the supercell method. Journal of Physics C: Solid State Physics, 18(5), 973-982. doi:10.1088/0022-3719/18/5/005Catlow, C. R. A., & Cormack, A. N. (1987). Computer modelling of silicates. International Reviews in Physical Chemistry, 6(3), 227-250. doi:10.1080/01442358709353406Gale, J. D. (1997). GULP: A computer program for the symmetry-adapted simulation of solids. Journal of the Chemical Society, Faraday Transactions, 93(4), 629-637. doi:10.1039/a606455hGale, J. D., & Rohl, A. L. (2003). The General Utility Lattice Program (GULP). Molecular Simulation, 29(5), 291-341. doi:10.1080/0892702031000104887Kiselev, A. V., Lopatkin, A. A., & Shulga, A. A. (1985). Molecular statistical calculation of gas adsorption by silicalite. Zeolites, 5(4), 261-267. doi:10.1016/0144-2449(85)90098-3Sastre, G., Lewis, D. W., & Catlow, C. R. A. (1996). Structure and Stability of Silica Species in SAPO Molecular Sieves. The Journal of Physical Chemistry, 100(16), 6722-6730. doi:10.1021/jp953362fYanai, T., Tew, D. P., & Handy, N. C. (2004). A new hybrid exchange–correlation functional using the Coulomb-attenuating method (CAM-B3LYP). Chemical Physics Letters, 393(1-3), 51-57. doi:10.1016/j.cplett.2004.06.011Tawada, Y., Tsuneda, T., Yanagisawa, S., Yanai, T., & Hirao, K. (2004). A long-range-corrected time-dependent density functional theory. The Journal of Chemical Physics, 120(18), 8425-8433. doi:10.1063/1.1688752Schäfer, A., Horn, H., & Ahlrichs, R. (1992). Fully optimized contracted Gaussian basis sets for atoms Li to Kr. The Journal of Chemical Physics, 97(4), 2571-2577. doi:10.1063/1.463096Wozniak, K., He, H., Klinowski, J., Jones, W., & Barr, T. L. (1995). ESCA, Solid-State NMR, and X-ray Diffraction Monitor the Hydrogen Bonding in a Complex of 1,8-Bis(dimethylamino)naphthalene with 1,2-Dichloromaleic Acid. The Journal of Physical Chemistry, 99(40), 14667-14677. doi:10.1021/j100040a014Rodriguez, I., Sastre, G., Corma, A., & Iborra, S. (1999). Catalytic Activity of Proton Sponge: Application to Knoevenagel Condensation Reactions. Journal of Catalysis, 183(1), 14-23. doi:10.1006/jcat.1998.2380Wozniak, K., He, H., Klinowski, J., Barr, T. L., & Milart, P. (1996). ESCA and Solid-State NMR Studies of Ionic Complexes of 1,8-Bis(dimethylamino)naphthalene. The Journal of Physical Chemistry, 100(27), 11420-11426. doi:10.1021/jp9537320Wo?naik, K., Krygowski, T. M., Pawlak, D., Kolodziejski, W., & Grech, E. (1997). Solid-state NMR and x-ray diffraction studies of ionic complex of 1,8-bis(dimethylamino)naphthalene (DMAN) with picrolonic acid. Journal of Physical Organic Chemistry, 10(11), 814-824. doi:10.1002/(sici)1099-1395(199711)10:113.0.co;2-

Decoding microbial genomes to understand their functional roles in human complex diseases

Complex diseases such as cardiovascular disease (CVD), obesity, inflammatory bowel disease (IBD), kidney disease, type 2 diabetes (T2D), and cancer have become a major burden to public health and affect more than 20% of the population worldwide. The etiology of complex diseases is not yet clear, but they are traditionally thought to be caused by genetics and environmental factors (e.g., dietary habits), and by their interactions. Besides this, increasing pieces of evidence now highlight that the intestinal microbiota may contribute substantially to the health and disease of the human host via their metabolic molecules. Therefore, decoding the microbial genomes has been an important strategy to shed light on their functional potential. In this review, we summarize the roles of the gut microbiome in complex diseases from its functional perspective. We further introduce artificial tools in decoding microbial genomes to profile their functionalities. Finally, state-of-the-art techniques have been highlighted which may contribute to a mechanistic understanding of the gut microbiome in human complex diseases and promote the development of the gut microbiome-based personalized medicine.</p

The first zeolite with a tri-directional extra-large 14-ring pore system derived using a phosphonium-based organic molecule

[EN] A new germanosilicate zeolite (denoted as ITQ-53) with extra-large pores has been synthesised using tri-tertbutylmethylphosphonium cation as the organic structure directing agent (OSDA). Rotation electron diffraction (RED) was used to identify ITQ-53 from an initially-synthesised sample containing impurities, and to solve its structure. The structure was refined against PXRD data of pure ITQ-53 samples obtained after synthesis optimisation. ITQ-53 is the first example of extra-large pore zeolites with tri-directional interconnected 14 x 14 x 14-ring channels. It is stable up to at least 650 degrees C. The structure of ITQ-53 changes from monoclinic to orthorhombic upon calcination.This work was supported by the Spanish Government (MAT2012-38567-C02-01, Consolider Ingenio 2010-Multicat CSD-2009-00050 and Severo Ochoa SEV-2012-0267), the Swedish Research Council (VR), the Swedish Governmental Agency for Innovation Systems (VINNOVA) and the Knut & Alice Wallenberg Foundation through a grant for purchasing the TEMs and the project grant 3DEM-NATUR. Yifeng Yun thanks the China Scholarship Council (CSC).Yun, Y.; Hernández Rodríguez, M.; Wan, W.; Zou, X.; Jorda Moret, JL.; Cantin Sanz, A.; Rey Garcia, F.... (2015). The first zeolite with a tri-directional extra-large 14-ring pore system derived using a phosphonium-based organic molecule. Chemical Communications. 51(36):7602-7605. https://doi.org/10.1039/c4cc10317cS760276055136C. Baerlocher and L.McCusker, Database of Zeolite Structures: http://www.iza-structure.org/databases/Estermann, M., McCusker, L. B., Baerlocher, C., Merrouche, A., & Kessler, H. (1991). A synthetic gallophosphate molecular sieve with a 20-tetrahedral-atom pore opening. Nature, 352(6333), 320-323. doi:10.1038/352320a0Su, J., Wang, Y., Lin, J., Liang, J., Sun, J., & Zou, X. (2013). A silicogermanate with 20-ring channels directed by a simple quaternary ammonium cation. Dalton Trans., 42(5), 1360-1363. doi:10.1039/c2dt32231eWei, Y., Tian, Z., Gies, H., Xu, R., Ma, H., Pei, R., … Lin, L. (2010). Ionothermal Synthesis of an Aluminophosphate Molecular Sieve with 20-Ring Pore Openings. Angewandte Chemie International Edition, 49(31), 5367-5370. doi:10.1002/anie.201000320Sun, J., Bonneau, C., Cantín, Á., Corma, A., Díaz-Cabañas, M. J., Moliner, M., … Zou, X. (2009). The ITQ-37 mesoporous chiral zeolite. Nature, 458(7242), 1154-1157. doi:10.1038/nature07957Corma, A., Diaz-Cabanas, M. J., Jiang, J., Afeworki, M., Dorset, D. L., Soled, S. L., & Strohmaier, K. G. (2010). Extra-large pore zeolite (ITQ-40) with the lowest framework density containing double four- and double three-rings. Proceedings of the National Academy of Sciences, 107(32), 13997-14002. doi:10.1073/pnas.1003009107Dorset, D. L., Strohmaier, K. G., Kliewer, C. E., Corma, A., Díaz-Cabañas, M. J., Rey, F., & Gilmore, C. J. (2008). Crystal Structure of ITQ-26, a 3D Framework with Extra-Large Pores. Chemistry of Materials, 20(16), 5325-5331. doi:10.1021/cm801126tDorset, D. L., Kennedy, G. J., Strohmaier, K. G., Diaz-Cabañas, M. J., Rey, F., & Corma, A. (2006). P-Derived Organic Cations as Structure-Directing Agents:  Synthesis of a High-Silica Zeolite (ITQ-27) with a Two-Dimensional 12-Ring Channel System. Journal of the American Chemical Society, 128(27), 8862-8867. doi:10.1021/ja061206oCorma, A., Diaz-Cabanas, M. J., Jorda, J. L., Rey, F., Sastre, G., & Strohmaier, K. G. (2008). A Zeolitic Structure (ITQ-34) with Connected 9- and 10-Ring Channels Obtained with Phosphonium Cations as Structure Directing Agents. Journal of the American Chemical Society, 130(49), 16482-16483. doi:10.1021/ja806903cHernández-Rodríguez, M., Jordá, J. L., Rey, F., & Corma, A. (2012). Synthesis and Structure Determination of a New Microporous Zeolite with Large Cavities Connected by Small Pores. Journal of the American Chemical Society, 134(32), 13232-13235. doi:10.1021/ja306013kSimancas, R., Jordá, J. L., Rey, F., Corma, A., Cantín, A., Peral, I., & Popescu, C. (2014). A New Microporous Zeolitic Silicoborate (ITQ-52) with Interconnected Small and Medium Pores. Journal of the American Chemical Society, 136(9), 3342-3345. doi:10.1021/ja411915cSimancas, R., Dari, D., Velamazan, N., Navarro, M. T., Cantin, A., Jorda, J. L., … Rey, F. (2010). Modular Organic Structure-Directing Agents for the Synthesis of Zeolites. Science, 330(6008), 1219-1222. doi:10.1126/science.1196240Hua, W., Chen, H., Yu, Z.-B., Zou, X., Lin, J., & Sun, J. (2014). A Germanosilicate Structure with 11×11×12-Ring Channels Solved by Electron Crystallography. Angewandte Chemie International Edition, 53(23), 5868-5871. doi:10.1002/anie.201309766Yun, Y., Wan, W., Rabbani, F., Su, J., Xu, H., Hovmöller, S., … Zou, X. (2014). Phase identification and structure determination from multiphase crystalline powder samples by rotation electron diffraction. Journal of Applied Crystallography, 47(6), 2048-2054. doi:10.1107/s1600576714023875Zhang, D., Oleynikov, P., Hovmöller, S., & Zou, X. (2010). Collecting 3D electron diffraction data by the rotation method. Zeitschrift für Kristallographie, 225(2-3). doi:10.1524/zkri.2010.1202X. Zou , S.Hovmoller and P.Oleynikov, Electron Crystallography: Electron Microscopy and Electron Diffraction, Oxford University Press, 2011, ISBN: 978-0-19-958020-0Wan, W., Sun, J., Su, J., Hovmöller, S., & Zou, X. (2013). Three-dimensional rotation electron diffraction: softwareREDfor automated data collection and data processing. Journal of Applied Crystallography, 46(6), 1863-1873. doi:10.1107/s0021889813027714Martinez-Franco, R., Moliner, M., Yun, Y., Sun, J., Wan, W., Zou, X., & Corma, A. (2013). Synthesis of an extra-large molecular sieve using proton sponges as organic structure-directing agents. Proceedings of the National Academy of Sciences, 110(10), 3749-3754. doi:10.1073/pnas.1220733110Su, J., Kapaca, E., Liu, L., Georgieva, V., Wan, W., Sun, J., … Zou, X. (2014). Structure analysis of zeolites by rotation electron diffraction (RED). Microporous and Mesoporous Materials, 189, 115-125. doi:10.1016/j.micromeso.2013.10.014Guo, P., Liu, L., Yun, Y., Su, J., Wan, W., Gies, H., … Zou, X. (2014). Ab initio structure determination of interlayer expanded zeolites by single crystal rotation electron diffraction. Dalton Trans., 43(27), 10593-10601. doi:10.1039/c4dt00458bJiang, J., Yun, Y., Zou, X., Jorda, J. L., & Corma, A. (2015). ITQ-54: a multi-dimensional extra-large pore zeolite with 20 × 14 × 12-ring channels. Chemical Science, 6(1), 480-485. doi:10.1039/c4sc02577fWillhammar, T., Burton, A. W., Yun, Y., Sun, J., Afeworki, M., Strohmaier, K. G., … Zou, X. (2014). EMM-23: A Stable High-Silica Multidimensional Zeolite with Extra-Large Trilobe-Shaped Channels. Journal of the American Chemical Society, 136(39), 13570-13573. doi:10.1021/ja507615bPatinec, V., Wright, P. A., Lightfoot, P., Aitken, R. A., & Cox, P. A. (1999). Synthesis of a novel microporous magnesioaluminophosphate, STA-6, containing an unbound azamacrocycle †. Journal of the Chemical Society, Dalton Transactions, (22), 3909-3911. doi:10.1039/a907259dWragg, D. S., Morris, R., Burton, A. W., Zones, S. I., Ong, K., & Lee, G. (2007). The Synthesis and Structure of SSZ-73:  an All-Silica Zeolite with an Unusual Framework Topology. 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Synthesis of an extra-large molecular sieve using proton sponges as organic structure-directing agents

The synthesis of crystalline microporous materials containing large pores is in high demand by industry, especially for the use of these materials as catalysts in chemical processes involving bulky molecules. An extra-large-pore silicoaluminophosphate with 16-ring openings, ITQ-51, has been synthesized by the use of bulky aromatic proton sponges as organic structure-directing agents. Proton sponges show exceptional properties for directing extra-large zeolites because of their unusually high basicity combined with their large size and rigidity. This extra-large-pore material is stable after calcination, being one of the very few examples of hydrothermally stable molecular sieves containing extra-large pores. The structure of ITQ-51 was solved from submicrometer-sized crystals using the rotation electron diffraction method. Finally, several hypothetical zeolites related to ITQ-51 have been proposed.The authors gratefully acknowledge Dr. Alejandro Vidal-Moya for the 27Al MQ MAS NMR experiment. The authors also acknowledge financial support from Ministerio de Economia y Competitividad of Spain (MAT2012-37160), Consolider Ingenio 2010-MULTICAT, Generalitat Valenciana through the PROMETEO program, Universitat Politecnica de Valencia through PAID-06-11 (n.1952), the Swedish Research Council (VR), the Swedish Governmental Agency for Innovation Systems (VINNOVA), and the Goran Gustafsson Foundation. M. M. also acknowledges "Subprograma Ramon y Cajal" for Contract RYC-2011-08972. The TEM used in this study was purchased from a grant by the Knut and Alice Wallenberg Foundation.Martínez Franco, R.; Moliner Marin, M.; Yun, Y.; Sun, J.; Wan, W.; Zou, X.; Corma Canós, A. (2013). Synthesis of an extra-large molecular sieve using proton sponges as organic structure-directing agents. Proceedings of the National Academy of Sciences. 110(10):3749-3754. https://doi.org/10.1073/pnas.1220733110S374937541101