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Hybrid Architecture (hybrid + architecture)
Selected AbstractsA CdSe Nanowire/Quantum Dot Hybrid Architecture for Improving Solar Cell PerformanceADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Yanghai Yu Abstract Incorporating colloidal CdSe quantum dots (QDs) into CdSe nanowire (NW)-based photoelectrochemical solar cells increases their incident-photon-to-carrier conversion efficiencies (IPCE) from 13% to 25% at 500,nm. While the effect could, in principle, stem from direct absorption and subsequent carrier generation by QDs, the overall IPCE increase occurs across the entire visible spectrum, even at wavelengths where the dots do not absorb light. This beneficial effect originates from an interplay between NWs and QDs where the latter fill voids between interconnected NWs, providing electrically accessible conduits, in turn, enabling better carrier transport to electrodes. The presence of QDs furthermore reduces the residual polarization anisotropy of random NW networks. Introducing QDs therefore addresses an important limiting constraint of NW photoelectrochemical solar cells. The effect appears to be general and may aid the future design and implementation of other NW-based photovoltaics. [source] Electro-Optical Materials: Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon Nanotubes (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Mater. Hybrid assemblies of zinc oxide (ZnO) nanowires grown on carbon nanotubes (CNTs) are presented by A. J. Hart et al. on page 2470. The foreground shows a transmission electron micrograph of an individual hybrid bundle where the ZnO nanowires extend radially from the surface of the CNTs. The background shows a scanning electron micrograph of the sidewall of a ZnO/CNT hybrid forest. Color was added using Adobe Photoshop. [source] Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon NanotubesADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Jong G. Ok Abstract The fabrication and characterization of hybrid architectures of ZnO nanowires (ZNWs) grown on organized carbon nanotubes (CNTs), by a two-step chemical vapor deposition (CVD) process involving CNT growth from a hydrocarbon source followed by ZNW growth using a Zn metal source, is reported. The ZNWs grow uniformly and radially from individual CNTs and CNT bundles, and the aligned morphology of the CNTs is not disturbed by the ZNW growth process. The nucleation and growth of ZnO crystals on CNTs are analyzed in relation to the classical vapor,solid mechanism. Importantly, the CNTs make uniform and distributed electrical contact to the ZNWs, with up to a 1000-fold yield advantage over conventional ZNW growth on a flat substrate. Hybrid ZNW/CNT sheets are fabricated by scalable CVD, rolling, and printing methods; and their electrical properties, which are governed by transport through the anisotropic CNT network, are characterized. Functional interaction between the ZNWs and CNTs is demonstrated by photoconductive behavior and photocurrent generation of the hybrid material under UV illumination. There is significant future opportunity to extend these processing methods to fabricate other functional oxides on CNTs, and to build devices that harness the attractive properties of ZNWs and CNTs with high volumetric efficiency over large areas. [source] Autocatalytic Creation of Closed Dimer and Extended Helix Metallosupramolecular ArchitecturesCHEMISTRY - A EUROPEAN JOURNAL, Issue 39 2009Nobuto Yoshinari Hybrid architectures: Self-organization of the xylyl-linked dicobalt(III) complex with an L -cysteine residue into homochiral dimeric and helix supramolecular structures is reported (see figure). These two structures were randomly and exclusively formed in the absence of any external stimuli if [HgBr4]2, was incorporated as the counter ion, thanks to the conformational bistability of the xylyl linker. [source] A DVB/Inmarsat hybrid architecture for asymmetrical broadband mobile satellite servicesINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 2 2006Bjørn Roger Andersen Abstract In order to bridge the gap, both regulatory and technologically, between offering mobile satellite services at L-band today and broadband mobile services at C-band, Ku-band or Ka-band in the future, a short-term solution is foreseen. Therefore, a DVB/Inmarsat hybrid service offering bi-directional asymmetrical satellite connectivity, with a broadband receive channel at Ku-band based on DVB-S, and with a transmit channel at L-band based on Inmarsat Mobile Packet Data Service, has successfully been developed, implemented and tested. The article focuses on the rationale for, and a technical solution, and how this can be evolved to support use of Inmarsat Broadband Global Area Access as transmit channel at L-band. There are no regulatory issues associated with global operation of such a system, and the users can access the services using cost-efficient off-the-shelf equipment, since the well established Inmarsat and DVB standards are utilized. The system has proved its feasibility to offer services like Internet access, email access, fast file transfers, and IP streaming of audio and video, in addition to the traditional Inmarsat services. Copyright © 2006 John Wiley & Sons, Ltd. [source] Robust Navigation and Mapping Architecture for Large EnvironmentsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 10 2003Favio Masson This paper addresses the problem of Simultaneous Localization and Mapping (SLAM) for very large environments. A hybrid architecture is presented that makes use of the Extended Kalman Filter to perform SLAM in a very efficient form and a Monte Carlo localizer to resolve data association problems potentially present when returning to a known location after a large exploration period. Algorithms to improve the convergence of the Monte Carlo filter are presented that consider vehicle and sensor uncertainty. The proposed algorithm incorporates significant integrity to the standard SLAM algorithms by providing the ability to handle multimodal distributions over robot pose in real time during the re-localization process. Experimental results in outdoor environments are presented to demonstrate the performance of the algorithm proposed. © 2003 Wiley Periodicals, Inc. [source] A three-dimensional hybrid framework based on novel [Co4Mo4] bimetallic oxide clusters with 3,5-bis(3-pyridyl)-1,2,4-triazole ligandsACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2009Quan-Guo Zhai In the title organic,inorganic hybrid complex, poly[[[,-3,5-bis(3-pyridyl)-1,2,4-triazole]tri-,3 -oxido-tetra-,2 -oxido-oxidodicobalt(II)dimolybdenum(VI)] monohydrate], {[Co2Mo2O8(C12H9N5)]·H2O}n, the asymmetric unit is composed of two CoII centers, two [MoVIO4] tetrahedral units, one neutral 3,5-bis(3-pyridyl)-1,2,4-triazole (BPT) ligand and one solvent water molecule. The cobalt centers both exhibit octahedral [CoO5N] coordination environments. Four CoII and four MoVI centers are linked by ,2 -oxide and/or ,3 -oxide bridges to give an unprecedented bimetallic octanuclear [Co4Mo4O22N4] cluster, which can be regarded as the first example of a metal-substituted octamolybdate and exhibits a structure different from those of the eight octamolybdate isomers reported to date. The bimetallic oxide clusters are linked to each other through corner-sharing to give two-dimensional inorganic layers, which are further bridged by trans -BPT ligands to generate a three-dimensional organic,inorganic hybrid architecture with six-connected distorted ,-Po topology. [source] Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon NanotubesADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Jong G. Ok Abstract The fabrication and characterization of hybrid architectures of ZnO nanowires (ZNWs) grown on organized carbon nanotubes (CNTs), by a two-step chemical vapor deposition (CVD) process involving CNT growth from a hydrocarbon source followed by ZNW growth using a Zn metal source, is reported. The ZNWs grow uniformly and radially from individual CNTs and CNT bundles, and the aligned morphology of the CNTs is not disturbed by the ZNW growth process. The nucleation and growth of ZnO crystals on CNTs are analyzed in relation to the classical vapor,solid mechanism. Importantly, the CNTs make uniform and distributed electrical contact to the ZNWs, with up to a 1000-fold yield advantage over conventional ZNW growth on a flat substrate. Hybrid ZNW/CNT sheets are fabricated by scalable CVD, rolling, and printing methods; and their electrical properties, which are governed by transport through the anisotropic CNT network, are characterized. Functional interaction between the ZNWs and CNTs is demonstrated by photoconductive behavior and photocurrent generation of the hybrid material under UV illumination. There is significant future opportunity to extend these processing methods to fabricate other functional oxides on CNTs, and to build devices that harness the attractive properties of ZNWs and CNTs with high volumetric efficiency over large areas. [source] Polyphenylene Dendrimer-Templated In Situ Construction of Inorganic,Organic Hybrid Rice-Shaped ArchitecturesADVANCED FUNCTIONAL MATERIALS, Issue 1 2010Xiaoying Qi Abstract A novel dendrimer-templating method for the synthesis of CuO nanoparticles and the in situ construction of ordered inorganic,organic CuO,G2Td(COOH)16rice-shaped architectures (RSAs) with analogous monocrystalline structures are reported. The primary CuO nanoparticles are linked by the G2Td(COOH)16 dendrimer. This method provides a way to preserve the original properties of primary CuO nanoparticles in the ordered hybrid nanomaterials by using the 3D rigid polyphenylene dendrimer (G2Td(COOH)16) as a space isolation. The primary CuO nanoparticles with diameter of (6.3,±,0.4) nm are synthesized via four successive reaction steps starting from the rapid reduction of Cu(NO3)2 by using NaBH4 as reducer and G2Td(COOH)16 as surfactant. The obtained hybrid CuO,G2Td(COOH)16 RSA, formed in the last reaction step, possesses a crystal structure analogous to a monocrystal as observed by transmission electron microscopy(TEM). In particular, the formation process of the RSA is monitored by UV,vis, TEM, and X-ray diffraction. Small angle X-ray scattering and Fourier transform infrared spectroscopy are used to investigate the role of the dendrimer in the RSA formation process. The obtained results illuminate that Cu2+COO, coordination bonds play an indispensable role in bridging and dispersing the primary CuO nanoparticles to induce and maintain the hybrid RSA. More importantly, the RSA is retained through the Cu2+COO,coordination bonds even with HCl treatment, suggesting that the dendrimers and Cu2+ ions may form rice-shaped polymeric complexes which could template the assembly of CuO nanoparticles towards RSAs. This study highlights the feasibility and flexibility of employing the peculiar dendrimers to in-situ build up hybrid architectures which could further serve as templates, containers or nanoreactors for the synthesis of other nanomaterials. [source] | |||||||||||||