bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of InAs quantum wires on (001)InP: toward the realization of VCSEL structures with a stabilized polarization
Authors: Lamy J.‐M. , Levallois C. , Nakhar A. , Caroff P. , Paranthoen C. , Piron R. , Le Corre A. , Ramdane A. , Loualiche S. 
Published: May 2007

AbstractWe propose a new type of long‐wavelength vertical cavity surface emitting laser (VCSEL) which consists of quantum wires (QWires) layers of InAs/InGaAsP grown on InP(001) and dielectrics Bragg mirrors, in order to control the in plane polarization of output power. QWires and quantum wells growth are performed by molecular beam epitaxy. QWires present a strong photoluminescence dependence to the polarization in contrast to the quantum wells, a polarization rate of 33% is measured. The optically pumped VCSEL is fabricated by metallic bonding, which allows the deposition of two dielectrics Bragg mirrors. The VCSEL with an active region based on InGaAs/InGaAsP quantum wells exhibits a lasing emission at 1.578 µm at room temperature under continuous wave operation. The VCSEL with an active region based on quantum wires shows a luminescence at 1.53 µm strongly polarized along the direction [1$ \bar 1 $0] which is promising for the stabilization of in plane polarization of VCSEL emission. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The biocompatibility microorganisms‐carbon nanostructures for applications in microbial fuel cells
Authors: Morozan A. , Stamatin L. , Nastase F. , Dumitru A. , Vulpe S. , Nastase C. , Stamatin I. , Scott K. 
Published: May 2007

AbstractBionanocomposites Staphylococcus aureus /carbon nanotubes were prepared and their biocompatibility with different species of carbon nanotubes (CNTs) evaluated in terms of their incorporation into a microbial fuel cell (MFC) anodic design. Multi wall carbon nanotubes (MWNTs) with various morphologies and structures, as received, and synthesized by the pyrolysis of novolac with ferrocene addition were used. MWNTs were characterized by TEM and FT‐IR spectroscopy. Optical microscopy with fluorescent quantum dots (QDs) have been used for bio‐labeling, microorganisms‐CNTs biocompatibility and rapid identification of the colonies developed. Designed BNCs are good culture cells media and the electrodes based on synthesized CNTs could be used with good effects in MFCs, from the point of view of bacteria biocompatibility. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetotransport in high mobility epitaxial graphene
Authors: Berger Claire , Song Zhimin , Li Xuebin , Wu Xiaosong , Brown Nate , Maud Duncan , Naud Cécile , de Heer Walt A. 
Published: May 2007

AbstractEpitaxial graphene layers grown on single‐crystal SiC have large structural coherence domains and can be easily patterned into submicron structures using standard microelectronics lithography techniques. Patterned structures show two‐dimensional electron gas properties with mobilities exceeding 3 m2/Vs. Magnetotransport measurements (Shubnikov–de Haas oscillations) indicate that the transport properties are dominated by the highly doped graphene layer at the silicon carbide interface. They reveal the Dirac nature of the charge carriers as predicted for a single graphene layer. The properties of Dirac fermions can be conveniently explored in epitaxial graphene with long electronic phase coherence at the micron scale. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic properties of nickel–zinc ferrite nanoparticles synthesized by coprecipitation
Authors: Corral‐Flores V. , Bueno‐Baqués D. , Paraguay‐Delgado F. , Botez C. E. , Ibarra‐Gómez R. , Ziolo R. 
Published: May 2007

AbstractThe influence of Zn substitution in the magnetic properties of a nanoscale system Ni1–x Znx Fe2O4 (where x = 0.0, 0.25, 0.50 and 0.75) was studied. The ferrites were synthesized by the coprecipitation technique. Transmission electron microscopy revealed a particle size around 4–15 nm, increasing with Zn content. FC/ZFC curves showed a typical superparamagnetic behavior in all samples. It was found that Zn substitution affects both the blocking temperature and the magnetization. The maximum magnetization at room temperature was 48 emu/g for the sample x = 0.50. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Construction of a two‐dimensional molecule–nanoparticle network using iron(II) bis(terpyridine) complex formation for molecular‐device applications
Authors: Hobara D. , Kondo S. , Choi M.‐S. , Ishioka Y. , Hirata S. , Murata M. , Azuma K. , Kasahara J. 
Published: May 2007

AbstractWe report a novel method to construct a two‐dimensional network of gold nanoparticles and metal complex molecules. Terpyridine derivatives having a thiol group are adsorbed on a gold nanoparticle surface through formation of a gold–sulfur bond. A monolayer of nanoparticles is then formed on the water surface, then transferred onto a Si/SiO2 substrate. The introduction of Fe2+ from a Fe(BF4)2 solution forms an iron(II) bis(terpyridine) complex, which simultaneously forms a network where the complex molecules interlink adjacent nanoparticles. The conductivity of the network, formed by the conjugated terpyridine derivative, is 4 or 5 orders of magnitude higher than that of non‐conjugated derivatives. Conductivity is modulated by gate voltage when a conjugated derivative is used but not when a non‐conjugated derivative is used. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Relaxor‐based thin film memories and the depolarizing field problem
Authors: Marqués Manuel I. , Aragó Carmen 
Published: May 2007

AbstractA simple model for a thin film memory based on a first neighbor interacting model is studied in detail. We have found that the minimum possible value for the thickness (D) as a function of the lateral size of the memory (L), the screening of the charges at the substrate (S) and the strength of the ferroelectric interaction (J), in order to obtain spontaneous polarization is D = SL /2J. We propose a new mechanism to obtain miniaturization of thin film memories to a single layer based on the use of relaxor ferroelectrics instead of regular ferroelectrics. Under the hypothesis of an internal organization of the random fields inside the nanofilm we show analytically how it should be possible to miniaturize the memory to a width as small as D = 1 for any value of L, J and S. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carbon‐isotopic composition of soil‐respired carbon dioxide in static closed chambers at equilibrium
Authors: Mora Germán , Raich James W. 
Published: May 2007

AbstractThe carbon‐isotopic composition (δ13C) of soil‐respired CO2 has been employed to evaluate soil carbon‐cycling processes and the contribution of soil CO2 emissions to canopy and tropospheric air. These evaluations can be successful only when accurate isotope values of soil‐respired CO2 are available. Here, we tested the robustness of δ13C values of soil‐respired CO2 obtained after long incubations in static closed chambers that were initially flushed with soil air. The rationale of this approach is that the equilibrium carbon‐isotope values of chamber‐headspace CO2 are theoretically equal to those of CO2 produced within the soil. Static closed chambers were installed in replicated grass monocultures, and measurements of headspace CO2 concentrations and δ13C values were performed at regular time intervals for 24 h in July 2005. The results revealed no significant effects of grass species on headspace CO2 concentrations or δ13C values (repeated measures analysis of variance (ANOVA), P > 0.1). As predicted by theory, isotope values asymptotically approached equilibrium conditions, which in our experimental setting occurred after 10 h. This good match between model predictions and our results suggests that an accurate determination of δ13C values of CO2 produced within soils is obtained through the isotopic measurement of chamber‐headspace CO2 once equilibrium conditions have been reached with the underlying soils. An additional advantage of this approach is that only one sample per chamber is required, which, combined with the low uncertainties of these measurements, facilitates the investigation of the spatial (landscape) variability of soil‐respired CO2. Copyright © 2007 John Wiley & Sons, Ltd.
Indigo Carmine degradation by hypochlorite in aqueous medium monitored by electrospray ionization mass spectrometry
Authors: de Urzedo Ana P. F. M. , Nascentes Clésia C. , Diniz Maria E. R. , Catharino Rodrigo R. , Eberlin Marcos N. , Augusti Rodinei 
Published: May 2007

AbstractThe degradation of the dye Indigo Carmine by hypochlorite in aqueous solution was monitored by electrospray ionization mass spectrometry in the negative ion mode (ESI(—)‐MS). Hypochlorite was highly efficient in removing the color of aqueous solutions of the dye. ESI(—)‐MS monitoring showed that concomitant with the Indigo Carmine consumption two transient species appeared (detected as doubly charged anions) probably formed via a net insertion of two hydroxyl groups at the exocyclic CC bond followed by the incorporation of two (mainly) or one oxygen atoms at the indolic rings of the dye. Structures of these products were proposed based on the ESI(—)‐MS/MS data and high accuracy mass measurements. These two transient intermediates quickly decomposed, both in the condensed and in the gas phase, to yield mono‐charged anions. Based on these results, a route for the Indigo Carmine degradation by hypochlorite in aqueous solution has been proposed. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of twenty‐five elements in lichens by sector field inductively coupled plasma mass spectrometry and microwave‐assisted acid digestion
Authors: Pino Anna , Alimonti Alessandro , Botrè Francesco , Minoia Claudio , Bocca Beatrice , Conti Marcelo E. 
Published: May 2007

AbstractA simple and efficient digestion method for rapid sample preparation and quantification of 25 chemical elements in lichens by sector field inductively coupled plasma mass spectrometry is described. A microwave (MW)‐assisted acid digestion was carried out at atmospheric pressure simultaneously handling up to 80 samples in screw‐capped disposable polystyrene tubes. This digestion procedure was compared with the established MW digestion in closed vessels in order to examine its potential applicability in routine analysis for environmental monitoring. Three certified reference materials, i.e. BCR 482 (lichens), BCR 62 (olive leaves) and BCR 100 (beech leaves), as well as a small set of real samples were analyzed. Limits of quantification, accuracy and precision of the method were assessed. The majority of the elements were totally recovered from the lichens and from the other vegetable matrices. Low contamination risk, simplicity, time‐saving, and applicability in routine analyses make this method very suitable for use in extensive screening campaigns. Copyright © 2007 John Wiley & Sons, Ltd.
Factors influencing enantiomeric fractions of hexabromocyclododecane measured using liquid chromatography/tandem mass spectrometry
Authors: Marvin Chris H. , MacInnis Gordia , Alaee Mehran , Arsenault Gilles , Tomy Gregg T. 
Published: May 2007

AbstractHexabromocyclododecane (HBCD), the most heavily produced of the cycloaliphatic brominated flame retardants (BFRs), is a mixture of three predominant diastereomers (α‐, β‐, and γ‐HBCD), each with a corresponding pair of enantiomers. We have investigated the liquid chromatography/mass spectrometry (LC/MS) behaviour of the HBCD enantiomers, and demonstrated that enantiomeric fractions (EFs) calculated using data uncorrected for instrument and/or matrix effects can result in potentially inaccurate EF values. However, use of labelled surrogates effectively corrects for these effects. Experiments with racemic HBCD standards indicate that chromatographic factors, including mobile phase composition and column bleed from chiral stationary phases, may be contributors to variations in the mass spectrometric response of the HBCD enantiomers. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of amprolium, carbadox, monensin, and tylosin in surface water by liquid chromatography/tandem mass spectrometry
Authors: Song Wenlu , Huang Min , Rumbeiha Wilson , Li Hui 
Published: May 2007

AbstractAntibiotics present in the environment are recently considered as emerging contaminants, and have raised increasing concerns about their potential risks to ecosystems and human health. In addition to the utilization for treatment, antibiotics are also routinely added as supplements in livestock feed to promote animal growth. A portion of the administered dose used for these purposes can be excreted into animal manure, and land application of the animal manure as plant fertilizers enhances the dissemination of antibiotics in the environment. It is a common practice to simultaneously administer multiple classes of antibiotics to livestock in an animal production farm. This study attempts to develop a protocol to determine four commonly used veterinary pharmaceuticals, amprolium, carbadox, monensin, and tylosin, in surface runoff from a livestock farm. A single‐cartridge solid‐phase extraction procedure was developed to simultaneously extract these veterinary antibiotics from surface water which were subsequently analyzed by liquid chromatography/tandem mass spectrometry. The extraction recoveries of spiked samples ranged from 89 to 113%, and the limits of quantitation were 8, 25, 1, and 35 ng/L for amprolium, carbodox, monensin, and tylosin, respectively. In the surface runoff from a livestock farm, amprolium was most frequently detected with the concentration range of 10–288 ng/L. Monensin was frequently detected with concentrations up to 37 ng/L. Tylosin was detected in two out of eleven samples, and carbadox was not detected in the surface runoff. The results indicate that the developed analytical method can be utilized to determine multiple classes of veterinary antibiotics present in surface runoff originating from animal farms. Copyright © 2007 John Wiley & Sons, Ltd.
A simple and selective method for the measurement of leucine and isoleucine from plasma using electrospray ionization tandem mass spectrometry
Authors: Bishop Michael J. , Crow Brian , Norton Dean , Kovalcik Kasey , George Joe , Bralley J. Alexander 
Published: May 2007

AbstractAn analytical method was developed for the rapid and accurate quantification of leucine (LEU) and isoleucine (ILE) from plasma using electrospray ionization tandem mass spectrometry (ESI‐MS/MS). The two isomeric amino acids were selectively detected using fragment ions unique to each compound. As a result, the need for chromatographic separation was avoided allowing for faster analysis (3 min). The possibility of any considerable interference between the two transitions was closely monitored, with no significant interference being observed. The presence of interfering compounds in plasma was also evaluated and found to minimal. The method was evaluated based upon linearity, with r2 ≥ 0.995 for both compounds, and accuracy, with no more than 8% deviation from the theoretical value. Copyright © 2007 John Wiley & Sons, Ltd.
3G evolution scenario toward 4G: Super 3G concept
Authors: Onoe Seizo , Nakamura Takehiro , Higuchi Kenichi 
Published: May 2007

AbstractThis paper describes the concept of Super 3G, the long‐term evolution (LTE) of 3G mobile communications systems. The objectives, technical proposals, the 3rd Generation Partnership Project (3GPP) standardization activities, and recent research activities on 4G radio access technologies are also described. Copyright © 2007 John Wiley & Sons, Ltd.
Bit‐interleaved space‐time‐frequency coded modulation with general linear precoding
Authors: Huang Tao , Yuan Chaowei , Sun Changlu 
Published: May 2007

AbstractA general linear precoding space‐time‐frequency bit‐interleaved coded modulation (GLP‐STF‐BICM) is presented. By expanding the dimensions of linear precoding (LP) matrix we achieve the correlation between the adjacent code matrices, and further time diversity is realized, and by further time diversity higher diversity gain is realized which effectively avoids possible burst errors in block fading channels. Also, the Singleton bound, channel capacity and BER performances are theoretically analyzed. Then the optimum criterion of the precoding matrix to maximize both diversity and coding gain is given. Furthermore, to reduce the decoding complexity, we present an efficient sphere iterative decoding (SID) algorithm for our scheme. Finally, we consider the downlink multiuser system model for GLP‐STF‐BICM, the scheduling and capability of the three multi‐access methods TDMA, F/TDMA, and S/F/TDMA are analyzed. The simulation results prove that the performance of the new scheme improved greatly in the frequency‐selective block fading channels. Copyright © 2007 John Wiley & Sons, Ltd.
A survey on analytic studies of Delay‐Tolerant Mobile Sensor Networks
Authors: Wang Yu , Dang Ha , Wu Hongyi 
Published: May 2007

AbstractThis paper presents a survey of analytic studies on the Delay‐Tolerant Mobile Sensor Network (DTMSN). We first give an overview of the analytic study on DTMSN, by identifying several key design components, that is, nodal mobility model, data delivery scheme, and queue management scheme. Then, several representative analytic models of DTMSN are exemplified and discussed in detail, with thorough comparison presented and possible open research issues enumerated. We expect that this paper will provide a deep understanding of the characteristics of DTMSN, and at the same time reveal the key design issues in its modeling and performance analysis, leading to useful insights for future theoretic study and protocol design. Copyright © 2007 John Wiley & Sons, Ltd.
Evaluating MobySpace‐based routing strategies in delay‐tolerant networks
Authors: Leguay Jérémie , Friedman Timur , Conan Vania 
Published: May 2007

AbstractBecause a delay‐tolerant network (DTN) can often be partitioned, routing is a challenge. However, routing benefits considerably if one can take advantage of knowledge concerning node mobility. This paper addresses this problem with a generic algorithm based on the use of a high‐dimensional Euclidean space, that we call MobySpace, constructed upon nodes' mobility patterns. We provide here an analysis and a large‐scale evaluation of routing schemes using MobySpace by replaying real mobility traces. The specific MobySpace evaluated is based on the frequency of visits of nodes to each possible location. We present simulation results for single‐copy and multi‐copy routing strategies that use MobySpace as a means to route bundles or to control flooding. We show that routing based on MobySpace can achieve good performance compared to a number of common algorithms. Copyright © 2007 John Wiley & Sons, Ltd.
Die Prandtl‐Glauertsche Näherung als Grundlage für ein Iterationsverfahren zur Berechnung kompressibler Unterschallströmungen
Authors: Hantzsche W. 
Published: May 2007

AbstractFür ein Iterationsverfahren zur Berechnung der kompressiblen Strömung, das von der Prandtlschen Näherung für dünne Profile als erstem Schritt ausgeht, wird die dritte Näherung berechnet. Unter Verwendung der konformen Abbildung, die das Außengebiet des Profils in der nach Prandtl affin verzerrten Strömungsebene in das eines Kreises überführt, läßt sich die dabei zu integrierende inhomogene Differentialgleichung allgemein lösen. Für die Strömung um die nichtangestellte Ellipse und den nichtangestellten Kreisbogen wird die dritte Näherung vollständig angegeben und numerisch ausgewertet. Der Kompressibilitätseinfluß steigt gegenüber der zweiten Näherung noch weiter an.
Affine Transformationen durch Doppel‐Photographie
Authors: Graf Ulrich 
Published: May 2007

AbstractBei der Diapositiv‐Herstellung von Schaubildern, Diagrammen, Nomogrammen, bei der Reproduktion von Zeichnungen aus Büchern u. ä. müßte eine in Größe und Format irgendwie vorliegende Urzeichnung auf das Diapositiv‐Format (beliebiger Größe) umgezeichnet werden, um daraus phototechnisch durch ähnliche Verkleinerung das (voll ausgefüllte) Diapositiv zu gewinnen. Unter Vermeidung der Umzeichnung läßt sich rein reproduktionstechnisch eine Verkleinerung in verschiedenen Maßstäben in Höhe und Breite (also eine affine Transformation) vornehmen, die die unmittelbare photomechanische Reproduktion auf beliebige Formate ermöglicht. Die bei diesem Verfahren maßgebenden geometrischen Gesetzmäßigkeiten werden untersucht.
Die Grundgleichungen der elastischen Stabilität in allgemeinen Koordinaten und ihre Integration
Authors: Neuber H. 
Published: May 2007

AbstractAusgehend vom Kräftegleichgewicht stellt Verfasser unter Anwendung des absoluten Differentialkalküls die Grundgleichungen der Stabilitätstheorie in beliebigen krummlinigen Koordinaten auf. Der Vorteil dieser Ableitung ist der, daß zunächst keine Voraussetzungen über das Formänderungsgesetz gemacht zu werden brauchen und daß die Größen, denen auch bei endlichen Verschiebungen Tensoreigenschaft zukommt, klar als Tensoren hervortreten. Das Integral der Grundgleichungen des anisotropen Kontinuums bei stationärer Vorspannung wird auf eine vektorielle Spannungsfunktion zurückgeführt, die einer Differentialgleichung sechster Ordnung genügt. Im Falle der Isotropie gelingt die Zurückführung auf Differentialgleichungen zweiter Ordnung.
Über die Analyse kurzer Kurvenzüge
Authors: Blume Hans 
Published: May 2007

AbstractEs wird ein Verfahren zur Feststellung der Voraussetzungen dafür hergeleitet, daß eine kurze Registrierkurve durch eine Summe exponentiell abklingender Wellenzüge konstanter Frequenz dargestellt werden kann. Ein Weg zur Berechnung der dabei auftretenden Konstanten wird gegeben. Da die Methode nicht auf die Darstellung durch solche Komponenten beschränkt ist, wird weiter die Frage erörtert, welche Arten von Wellenzügen zweckmäßig einer Analyse zugrunde zu legen sind.
Beiträge zur numerischen Lösung linearer Eigenwertprobleme.
Authors: Lehmann N. Joachim 
Published: May 2007

AbstractDie in einer gleichnamigen Arbeit begonnenen Untersuchungen über die Eingrenzung vorgeschriebener Eigenwerte werden fortgesetzt und abgeschlossen. Von den Ergebnissen der ersten Veröffentlichung ausgehend, wird zuerst ein Verfahren angegeben, das von unten und oben gegen den interessierenden Eigenwert konvergierende Näherungen liefert. Eine weitere Konstruktion führt nochmals auf untere Eigenwertschranken.
Über die äußere und innere Reibungsschicht bei Störungen laminarer Strömungen
Authors: Holstein H. 
Published: May 2007

AbstractDas Formelsystem, das zur Durchführung von Stabilitätsrechnungen an laminaren Reibungsschichten nach der Tollmienschen Methode erforderlich ist, wird — z. T. auf neuartige Weise — hergeleitet und übersichtlich zusammengestellt. Für die dabei auftretenden universellen Funktionen werden genauere Tabellen angegeben. Insbesondere zum Fall der angefachten und gedämpften Schwingungen werden einige neue Resultate mitgeteilt. Zu Ergebnissen aus dem neuesten Schrifttum zur Stabilitätstheorie, insbesondere von C. C. Lin und D. Meksyn, wird kritisch Stellung genommen.
Spannungsfunktionen für die von Kugel= und Kegelflächen begrenzten Körper und Kuppelproblem
Authors: Timpe A. 
Published: May 2007

AbstractIn vorliegendem Aufsatz wird der auf eine erzeugende biharmonische Funktion gestützte Lösungsschlüssel, den Verf. in Bd. 28 (1948) dieser Zeitschrift für die achsensymmetrische Deformation von Umdrehungskörpern in räumlichen Polarkoordinaten entwickelt hat zur Gewinnung von typischen Lösungen für die von Kugel‐ und Kegelflächen begrenzten Körper nutzbar gemacht, insbesondere einer Gruppe von “Brückenlösungen”, die für das Kuppelproblem (verteilte Belastung oder konzentrierte Last in der Kuppe) in Frage kommen. Anschließend Kegelprobleme.