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Hybrid Structures (hybrid + structure)

Distribution by Scientific Domains

Polymers and Materials Science	33%
Chemistry	33%
Physics and Astronomy	18%
3 Other Domains	16%

Selected Abstracts

Nanowires: A Microfluidic Approach for the Formation of Conductive Nanowires and Hollow Hybrid Structures (Adv. Mater.

ADVANCED MATERIALS, Issue 20 2010
20/2010)
The inside cover shows a scanning electron microscopy image of electrically conductive hybrid nanofibers made of tetrathiafulvalene/gold produced by hydrodynamic flow focusing in a microfluidic device, as reported in work by Josep Puigmartí-Luis and co-workers on p.,2255. The hybrid nanowires produced using this method are potential candidates for nanoscale sensor applications due to their electrical conductivity and their ease of functionalization. [source]

A Microfluidic Approach for the Formation of Conductive Nanowires and Hollow Hybrid Structures

ADVANCED MATERIALS, Issue 20 2010
Josep Puigmartí-Luis
A facile fabrication process for micro- and nanometer-scale hybrid structures employing a microfluidic reactor is described. The unique properties of hydrodynamic flow focusing are exploited to promote the formation of well-defined structures with dissimilar morphology and structure in a fast and simple way. The hybrid nanowires are potential candidates for nanometer-sized sensors due to their electrical conductivity and their ease of functionalization. [source]

A Molecular Double Decker: Extending the Limits of Current Metal,Molecule Hybrid Structures,

ANGEWANDTE CHEMIE, Issue 2 2010
Felix Eberle
Eine neue Art organisch-anorganischer Hybridverbindungen besteht aus zwei unabhängigen Molekülschichten, die durch eine Metallmonoschicht getrennt und zwischen zwei Elektroden eingelagert sind (siehe Bild). Die Monoschicht zeigt trotz ihrer rein zweidimensionalen Ausdehnung und der Gegenwart chemischer Bindungen auf beiden Seiten metallische Eigenschaften und könnte nützlich als Zwischenelektrode zur Steuerung von Ladungstransfer durch molekulare Funktionseinheiten sein. [source]

Optical Fiber/Nanowire Hybrid Structures for Efficient Three-Dimensional Dye-Sensitized Solar Cells,

ANGEWANDTE CHEMIE, Issue 47 2009
Benjamin Weintraub
Effizienter als in zweidimensionalen Einheiten ist die Energieumwandlung in dreidimensionalen farbstoffsensibilisierten Solarzellen (DSSCs) in einer Hybridstruktur aus optischen Fasern und Nanodrähten. Axiale Bestrahlung von innen erhöht die Energieumwandlungseffizienz einer Hybridstruktur mit der Form einer rechteckigen Faser (siehe Bild) bis zum Sechsfachen gegenüber der Bestrahlung von außen senkrecht zur Faserachse. [source]

Inorganic,Organic Hybrid Structures: Open-Framework Iron Phosphite,Oxalates of Varying Dimensionality

CHEMISTRY - A EUROPEAN JOURNAL, Issue 3 2007
Sukhendu Mandal
Abstract Inorganic,organic hybrid structures belonging to the family of iron phosphite,oxalates have been prepared by employing hydrothermal methods. Their structures, determined by single-crystal X-ray diffraction, show a hierarchy within the family. While compounds I and II are low dimensional, III,VI have three-dimensional structures. Compound I has edge-shared ladders of iron phosphite with oxalate units hanging from the iron centers. Compound II has a layer structure with a honeycomb-like arrangement. The three-dimensional hybrid structures have the oxalate units connected in both in-plane and out-of-plane modes. A newly identified secondary building unit (SBU-7) and the oxalate units satisfying the valence and coordination requirements in the structure of V are novel and noteworthy structural features. Magnetic studies show that the dominant interactions between the iron centers are antiferromagnetic. Similar to other known hybrid structures, the phosphite,oxalate structures appear to show wide compositional and structural diversity. [source]

Textured growth and microstructure of pulsed laser deposited Nb/Cr/SmCo5 hybrid structures

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2010
R. Schaarschuch
Abstract Hybrid structures based on superconducting Nb and highly coercive ferromagnetic SmCo5 films grown on MgO(100) substrates were fabricated by pulsed laser deposition under UHV conditions. Thin film architectures of SmCo5 on Nb and the reversed system both with and without Cr spacer layer between superconductor and ferromagnet were examined by transmission electron microscopy and X-ray diffraction concerning their microstructure and epitaxial relationship, respectively. For SmCo5 on Nb with thick intermediate Cr spacer the epitaxial relationship MgO(001)[100]//Cr(001)[110]//Nb(001)[110]//Cr(001)[110]//SmCo5(11,,,20)[0001]//Cr(001)[110] was found. With decreasing thickness of the Cr spacer layer the strength of the texture decreases and finally crystallinity of SmCo5 is lost. In the reversed layer system, Nb on Cr on SmCo5, with decreasing thickness of the Cr spacer layer the epitaxial relationships change from SmCo5(11,,,20)[0001]//Nb(001)[110] to local SmCo5(11,,,20) [0001]//Nb(110)[1,,,11] and the Nb texture changes from the (001)[110] component to a ,110, fibre. The orientation relationships observed are discussed with regard to elastic strain energy minimization. [source]

Structural Evolution and Copper-Ion Release Behavior of Cu-pHEMA Hybrids Synthesized In Situ,

ADVANCED ENGINEERING MATERIALS, Issue 11 2009
Yen-Yu Liu
Abstract A novel Cu-pHEMA hybrid was successfully prepared by in situ photopolymerization of 2-hydroxyethyl methacrylate (HEMA) monomer in the presence of Cu(II) copper ions, following an in situ chemical reduction. Experimental observations indicate that intermolecular interactions such as the coupling force and hydrogen bonding between the Cu and the hydroxyl groups further stabilize the hybrid structure to a considerable extent. Localization of the metallic copper particles within the pHEMA network structure as a result of those intermolecular interactions gives rise to the formation of discretely distributed nanocrystallites with particle sizes ranging from 5 to 25,nm in diameter. A crystallographic change of the Cu nanophase from an amorphous-like to a crystalline structure is observed as the H2O:HEMA molar ratio increases, upon synthesis, accompanied with an increase in the particle size. A relatively slow and sustained release of the Cu (in the form of cupric ions) from the hybrids was measured for a time period of about 10 days, which also illustrates a Cu(II)-induced proliferation of the endothelial cells over a relatively small range of release rate of the Cu from the hybrids. Such a new type of Cu-loaded hybrid hydrogel is expected to be compatible and may be considered as a candidate biomaterial for biomedical/therapeutic uses. [source]

Preparation-Condition Dependence of Hybrid SiO2 -Coated CdTe Nanocrystals with Intense and Tunable Photoluminescence

ADVANCED FUNCTIONAL MATERIALS, Issue 8 2010
Ping Yang
Abstract When aqueously prepared CdTe nanocrystals (NCs) are coated with a SiO2 shell containing Cd ions and a sulfur source, they show a drastic increase in photoluminescence (PL) efficiency with a significant red shift and spectral narrowing after reflux. This is ascribed to the creation of a hybrid structure characterized by the formation of CdS-like clusters in the vicinity of the NCs in the SiO2 shell. Since these clusters are close to the NCs, their effective size increases to reduce the quantum size effect. The dependences of the PL properties on the preparation conditions are systematically investigated. The PL efficiency increases from 28% to 80% in the best case with a red shift of 80,nm. The PL behaviors differ from those of normal CdTe NCs and include less temperature quenching and longer PL lifetime. The SiO2 coating enables bioconjugation with IgG without deterioration of PL efficiency, making hybrid NCs amenable for bioapplication. [source]

Clean and Flexible Modification Strategy for Carboxyl/Aldehyde-Functionalized Upconversion Nanoparticles and Their Optical Applications

ADVANCED FUNCTIONAL MATERIALS, Issue 24 2009
Huan-Ping Zhou
Abstract Rare-earth upconversion nanoparticles (UCNPs) exhibit great potential in luminescent biolabels and other multifunctional probes; however, their applications are limited by their low water solubility and the lack of binding groups. To address these problems, a clean and flexible strategy to modify hydrophobic monodisperse UCNPs into hydrophilic ones that are capped with functional groups is developed. The modification process is implemented by direct oxidation of oleic acid ligands with ozone under specific conditions, where the oleic acid (OA) ligands on the surface of the UCNPs can be converted into azelaic acid ligands (HOOC(CH2)7COOH) or azelaic aldehyde HOOC(CH2)7CHO, as is revealed by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) measurements. This oxidation process has no significant side-effects on the morphology, phase, composition, or luminescent properties of the UCNPs. Free carboxylic acid groups on the surface endow the UCNPs with good water solubility, while aldehyde groups at the surface provide binding sites for amino-containing molecules via Schiff-base condensation, such as 2-(4-aminophenylethylyl)-5-methoxy-2-(2-pyridyl)thiazole (MPTEA) and 2-aminoethanethiol hydrochloride (NH2CH2CH2SH·HCl, HEMA). A Ce4+ sensor is constructed based on the dual-emission arising from the different spectral responses of MPTEA and the UCNPs. Facilitated by the covalent linkage between the terminal aldehyde group on the UCNPs and the amino group in HEMA, a hybrid structure of UCNPs and Au NPs is fabricated. The effective coupling between the aldehyde group and the amino group suggests that these functionalized UCNPs have potential in combining other functional units for simultaneous biolabeling, or other optical applications. [source]

Hybrid identification of fuzzy rule-based models

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 1 2002
Sung-Kwun Oh
In this study, we propose a hybrid identification algorithm for a class of fuzzy rule-based systems. The rule-based fuzzy modeling concerns structure optimization and parameter identification using the fuzzy inference methods and hybrid structure combined with two methods of optimization theories for nonlinear systems. Two types of inference methods of a fuzzy model concern a simplified and linear type of inference. The proposed hybrid optimal identification algorithm is carried out using a combination of genetic algorithms and an improved complex method. The genetic algorithms determine initial parameters of the membership function of the premise part of the fuzzy rules. In the sequel, the improved complex method (being in essence a powerful auto-tuning algorithm) leads to fine-tuning of the parameters of the respective membership functions. An aggregate performance index with a weighting factor is proposed in order to achieve a balance between performance of the fuzzy model obtained for the training and testing data. Numerical examples are included to evaluate the performance of the proposed model. They are also contrasted with the performance of the fuzzy models existing in the literature. © 2002 John Wiley & Sons, Inc. [source]

Cooperative Activation in the Hydrolytic Kinetic Resolution of Epoxides by a Bis-Cobalt(III)salen-Calix[4]arene Hybrid

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010
Sander
Abstract A chiral, bimetallic cobalt(III)salen-calix[4]arene hybrid structure was prepared and tested in the hydrolytic kinetic resolution (HKR) of racemic epoxides. Kinetic studies have revealed that the two catalytic units on the upper rim of the calixarene scaffold are able to activate the reactants in a cooperative and primarily intramolecular mode. High enantioselective behaviour was observed and besides, a higher stability was found for the bimetallic catalyst as compared to a monometallic reference complex. [source]

An ultra-wideband bandpass filter using hybrid structure of microstrip and CPW

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2009
Xun Luo
Abstract An ultra-wideband (UWB) bandpass filter is proposed based on the hybrid structure of microstrip and coplanar waveguide (CPW). First, the detached-mode resonator is formed on the CPW layer, which composes a quarter-wavelength (,/4) multiple-mode resonator (MMR) with a short-stub and a ,/4 single-mode resonator. Then, two ,/4 microstrip open-stubs on the top side of the common substrate are introduced for bandwidth enhancement to meet the UWB passband limit. Quasi-elliptic function response and UWB operation are achieved. The simulated and measured results show an excellent agreement. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2470,2473, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24658 [source]

Direct bonding conditions of ferrite garnet layer on ion-exchanged glass waveguides

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 10 2008
Anne-Laure Joudrier
Abstract In order to realize an integrated optical isolator, a new hybrid optical structure has been proposed. This structure is composed of an active magneto-optic garnet layer with a strong refractive index, transferred on a passive ion-exchanged glass waveguide. Given the thermal restraints relating to the stability of the glass waveguides, the process used to achieve this hybrid structure is composed of two main steps: firstly, good quality garnet films were grown by liquid phase epitaxy, then these active films were bonded successfully on glass wafer. According to modelling, the thickness of the garnet layer does not exceed 300 nm for maintaining a good confinement. Good wafer bondings on ion-exchanged glass waveguides are obtained. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Neonatal salt-wasting and 11 ,-hydroxylase deficiency in a child carrying a homozygous deletion hybrid CYP11B2 (aldosterone synthase),CYP11B1 (11 ,-hydroxylase)

CLINICAL GENETICS, Issue 3 2004
B Ezquieta
This article reports the case of a boy diagnosed at 1.8 years of age with congenital adrenal hyperplasia due to 11 ,-hydroxylase deficiency. The patient showed salt-wasting episodes during the neonatal period. On molecular analysis, a homozygous deletion hybrid (CYP11B2,CYP11B1) involving the CYP11B locus at 8q24.3 was found. Southern blot analysis showed the break point of the chimera gene to be located before intron 5; sequence analysis identified it at exon 4 between codons 202 and 248. This CYP11B2(5,)/B1(3,) hybrid should lack aldosterone synthase activity (due to the CYP11B1 residues at exons 5 and 6), and the enzyme it codes for should not be promoted by adrenocorticotropic hormone (ACTH) (CYP11B2 promoter sequences). The patient phenotype , neonatal salt-wasting and 11 ,-hydroxylase deficiency , is in agreement with this hybrid structure. This is the first time a homozygous deletion hybrid generated by unequal crossover has been described in exon 4. This genetic lesion appears to be the reciprocal product from the recombination event that causes glucocorticoid-remediable aldosteronism, a duplication dominant allele (CYP11B2,CYP11B1/B2,CYP11B1) coding for additional aldosterone synthase activity regulated by ACTH. The clinical presentation of the condition in this patient contributes to the in vivo understanding of the regulation of this complex locus in which two ,duplicated' genes have evolved different regulatory and enzymatic activities involved in mineralocorticoid and glucocorticoid synthesis in the adrenal glands. The fact that this allele was first predicted and has now been documented clinically and molecularly in vivo is particularly noteworthy. [source]

Benzylamines as Versatile Agents for the One-Pot Synthesis and Highly Ordered Stacking of Anatase Nanoplatelets

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2008
Georg Garnweitner
Abstract The simple reaction of titanium isopropoxide in benzylamine is shown to lead to remarkably complex, highly ordered hybrid structures. These structures consist of anatase nanoplatelets that were stacked in a lamellar fashion with a small organic layer in between. By careful characterization of these structures, we show that indeed solely the benzylamine solvent is present in the organic moiety between the nanocrystals, which thereby provides both shape control and alignment of the inorganic crystals. The solvent also plays a central role during the anatase formation itself; hence, it enacts control on the forming materials on a multitude of levels.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Hybrid 2D and 3D Frameworks Based on ,-Keggin Polyoxometallates: Experiment and Simulation

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2005
Anne Dolbecq
Abstract The ,-Keggin polyoxomolybdate {,-PMoV8MoVI4O40,x(OH)xM4} is a versatile building unit, with M being either a ZnII or a LaIII capping ion located at the vertices of a slightly distorted tetrahedron. The charge of the Keggin unit depends on the number of protonated oxo bridging ligands, which has been shown to vary from 0 to 5. The Keggin entity can thus be either an anion (M = Zn, x = 0) or a cation (M = La, x = 3,5). The Zn derivative has been generated in situ by hydrothermal synthesis and forms a 2D material built from the connection of the cations by 4,4'-bipyridine ligands linked to the capping ZnII ions. The reaction of the chloride salt of the La derivative with di-, tri- and tetrasubstituted benzenecarboxylate ligands has allowed us to isolate 2D and 3D materials. The 3D materials seem to be the first examples of hybrid open frameworks based on Keggin building blocks. The 3D framework built from the connection of ,-Keggin units by trimesate ions exhibits tunnels filled only by water molecules, which can be partly removed and reintroduced at room temperature. Besides these experimental results, simulation has allowed us to generate two virtual hybrid structures derived from those of known silicates by replacing the Si ions by hypothetical ,-Keggin cations and the O -bridging ligands by terephthalate ions, thus showing that 3D frameworks with large pores can be envisioned in the chemistry of hybrid organic,inorganic materials based on ,-Keggin units and motivating further experimental investigations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

In Situ Damage Detection With Acoustic Emission Analysis During Cyclic Loading of Wire Reinforced EN AW-6082,

ADVANCED ENGINEERING MATERIALS, Issue 7 2010
Kay André Weidenmann
In the field of lightweight construction, hybrid structures such as reinforced metal matrix composites are highly qualified materials. The direct composite extrusion process allows for continuous manufacturing of wire reinforced aluminum matrix profiles. The aim is to increase the stiffness and specific strength in a way that the composite material shows better mechanical properties than the single matrix material. To determine and locate damage evolution during cyclic loading of spring steel reinforced EN AW-6082 matrix the acoustic emission analysis is used. Furthermore it allows for getting more information about the damage mechanisms during fatigue of the matrix and the final failure of the reinforcing element. The current work also includes the determination of damage evolution using strain measuring methods. [source]

Gold Nanoparticles Stabilized by Acetylene-Functionalized Multidentate Thioether Ligands: Building Blocks for Nanoparticle Superstructures

ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009
Torsten Peterle
Abstract Aiming at the formation of inorganic/organic hybrid gold nanoparticle superstructures, the design and synthesis of acetylene-monofunctionalized multidentate thioether ligands and their ability to stabilize gold nanoparticles are presented. Rather monodisperse gold particles with diameters of about 1,nm are obtained, which are coated by a small number of ligands, each comprising a silyl-protected acetylene. The acetylene is attached at the end of a rigid ethynylene-phenylene unit of variable length, leading to functionalized gold nanoparticles carrying acetylenes at different distances from the nanoparticle surface. These particles are interlinked by diacetylene formation and are investigated by transmission electron microscopy and UV/vis spectroscopy, revealing the formation of nanoparticle aggregates and small superstructures such as dimers or trimers while the nanoparticles themselves retain their integrity. The interparticle distance in small nanoparticle superstructures reflects the ethynylene-phenylene spacer length corroborating the wet chemical interlinking as the origin of these organic/inorganic hybrid structures. [source]

A Microfluidic Approach for the Formation of Conductive Nanowires and Hollow Hybrid Structures

An Inorganic/Organic Semiconductor "Sandwich" Structure Grown by Molecular Beam Epitaxy

ADVANCED MATERIALS, Issue 47 2009
S. Blumstengel
Preparation of ZnO/organic/ZnO "sandwich" semiconductor hybrid structures by molecular beam epitaxy is reported. Overgrowth of the organic layer becomes possible because ZnO epitaxy requires exceptionally low substrate temperatures. The molecule, a spirobifluorene derivative, withstands ZnO overgrowth without degradation of its optical properties. Excitonic coupling as well as optical gain in ZnO/organic/ZnO sandwich hybrid structures are demonstrated. [source]

Textured growth and microstructure of pulsed laser deposited Nb/Cr/SmCo5 hybrid structures

Light scattering study on hybrid structures of Zn1,x,yCdxMnySe quantum wells with ferromagnetic Co wires

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 3 2004
M. Sakuma
Abstract Sub-micron scale hybrid structures of Zn1,x,yCdxMnySe diluted magnetic semiconductor (DMS) quantum wells (QWs) with ferromagnetic Co wires have been fabricated for the purpose of applying local magnetic fields to the DMS-QW. The wire of DMS-QW with the width down to 100 nm was sandwiched between the Co wires. The magneto-optical properties are studied by spin-flip light scattering of paramagnetic Mn-ions in the DMS. The application of uniform magnetic fields higher than 0.25 T has been attained from the Co wires to the DMS-QWs. In addition, the field application from the Co to the DMS-QWs is switched on by weak magnetic fields of 0.03 T due to the magnetic shape anisotropy of the Co wires, which can realize the switching behavior of the spin alignment of Mn-ions in the DMS-QW. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Inorganic,Organic Hybrid Structures: Open-Framework Iron Phosphite,Oxalates of Varying Dimensionality

Defect-Enhanced Dispersion of Carbon Nanotubes in DNA Solutions

CHEMPHYSCHEM, Issue 14 2009
Jin Hee Kim
Nanotubes wrapped up: In nanotube,DNA hybrid structures (see figure), defects on the sidewall of carbon nanotubes effects the dispersibility. DNA is helically wrapped around the nanotubes in an irregular pattern and structural defects on the sidewall of the nanotubes provide additional sites for binding with DNA. [source]