bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the horseweed (Conyza canadensis) transcriptome using GS‐FLX 454 pyrosequencing and its application for expression analysis of candidate non‐target herbicide resistance genes
Authors: Peng Yanhui , Abercrombie Laura LG , Yuan Joshua S , Riggins Chance W , Sammons R Douglas , Tranel Patrick J , Stewart C Neal 
Published: August 2010

AbstractBACKGROUND: The de novo transcriptome sequencing of a weedy plant using GS‐FLX 454 technologies is reported. Horseweed (Conyza canadensis L.) was the first broadleaf weed to evolve glyphosate resistance in agriculture, and also is the most widely distributed glyphosate‐resistant weed in the United States and the world. However, available sequence data for this species are scant. The transcriptomic sequence should be useful for gene discovery, and to help elucidate the non‐target‐based glyphosate resistance mechanism and the genomic basis of weediness.RESULTS: Sequencing experiments yielded 411 962 raw reads, an average read length of 233 bp and a total dataset of 95.8 Mb (NCBI accession number SRA010952). After trimming and quality control, 379 152 high‐quality sequences were retained and assembled into contigs. The assembly resulted in 31 783 unique transcripts, including 16 102 contigs and 15 681 singletons. The average coverage depth for each contig and each nucleotide position was 22‐fold and 12‐fold respectively. A total of 16 306 unique sequences were annotated by searching a custom plant protein database. The utility of the transcriptome data was demonstrated by further exploration of ABC transporters, which were previously hypothesized to play a role in non‐target glyphosate resistance. Real‐time RT‐PCR primers were designed from the transcriptome data, which made it possible to assess expression patterns of 17 ABC transporters from resistant and susceptible horseweed accessions from Tennessee, with and without glyphosate treatment.CONCLUSION: These results show that GS‐FLX 454 sequencing is a powerful and cost‐effective platform for the development of functional genomic tools for a weed species. Copyright © 2010 Society of Chemical Industry
Formation of {100} facet‐terminated nanocrystalline diamond by microwave plasma chemical vapor deposition: Edge effect
Authors: Tang C. J. , Fernandes A. J. S. , Buijnsters J. G. , Abe I. , Domingues M. F. F. , Pinto J. L. 
Published: August 2010

Abstract{100} Facet‐terminated nanocrystalline and {100} textured large‐grained polycrystalline diamond (PCD) have been grown simultaneously not only on different substrates but also on the same substrate from a single deposition run using high‐power microwave plasma chemical vapor deposition (MPCVD). The synthesis of diamond with varying morphologies in the same deposition run was achieved by combining the effect of nitrogen addition on diamond growth and the influence of substrate size and geometry on the distribution of the plasma power density and temperature along the substrate. We have modeled the temperature distribution on the substrates by computer simulations using the finite element method. The formation mechanism of several morphologies including both {100} facet‐terminated nanocrystalline and {100} textured large‐grained PCD on one substrate is discussed based on this temperature analysis and other simulation results described in the literature.
Detailed study of superconductivity in nanostructured nanocrystalline boron doped diamond thin films
Authors: Mandal Soumen , Naud Cécile , Williams Oliver A. , Bustarret Étienne , Omnès Franck , Rodière Pierre , Meunier Tristan , Saminadayar Laurent , Bäuerle Christopher 
Published: August 2010

AbstractIn this paper, we report on the transport properties of nanostructured boron doped diamond thin films. The nanostructures made from polycrystalline boron doped diamond show clear evidence of superconductivity with critical temperatures in the Kelvin range and critical field in the Tesla range. Such robust superconducting properties in these superhard materials make them promising candidates for superconducting nanoelectromechanical systems.
Passivation of H‐terminated diamond with MOCVD‐aluminium nitride – a key to understand and stabilize its surface conductivity
Authors: Kueck Daniel , Scharpf Jochen , Ebert Wolfgang , Fikry Mohamed , Scholz Ferdinand , Kohn Erhard 
Published: August 2010

AbstractThe surface conductivity of hydrogen (H)‐terminated diamond still suffers from instabilities at high temperature especially in O‐containing atmosphere and/or under high power FET device operation. For devices based on this H‐induced surface conductivity concept, stabilization is thus essential. In this investigation AlN, deposited by MOCVD at 800 °C, has been used as passivation and gate dielectric in Surface Channel MESFET and MISFET structures. Despite the high deposition temperature, the H‐induced channel is still present in the case of both structures and can be fully modulated. Surface Channel MESFETs yield a maximum output current density of 200 mA/mm (at pS = 9.5 × 1012 cm−2) in enhancement mode of operation. MISFETs display 20 mA/mm current density (at pS = 2.1 × 1012 cm−2) in semi‐enhancement mode of operation, the maximum current being limited by AlN dielectric breakdown. The film shows strong adhesion. To explain all features consistently, it is proposed that the interfacial bonding is provided by a H‐double bond.
Diamond nanotextured surfaces for enhanced protein redox activity
Authors: Yang Nianjun , Smirnov Waldemar , Kriele Armin , Hoffmann Rene , Nebel Christoph E. 
Published: August 2010

AbstractA nanotextured diamond electrode was utilized to achieve optimized electrochemical redox‐interactions of cytochrome c (cyt c) with the diamond transducer. The nanotextured surface was realized using a top–down technology where diamond nanoparticles are used as etching masks. Macroscopic characterizations of the OH‐terminated surface using cyclic voltammetry reveal adsorption‐controlled cyt c/electrode interaction. The adsorption is assigned to the electrostatic attraction force of positively charged cyt c parts with the slightly negatively charged diamond surface in pH 7 buffer. Atomic force microscopy experiments in physiologic buffer solutions on flat diamond surface confirms the adsorption of cyt c on OH‐terminated diamond surfaces without structural changes of cyt c.
Diamond Schottky‐pn diode without trade‐off relationship between on‐resistance and blocking voltage
Authors: Makino Toshiharu , Kato Hiromitsu , Tokuda Norio , Ogura Masahiko , Takeuchi Daisuke , Oyama Kazuhiro , Tanimoto Satoshi , Okushi Hideyo , Yamasaki Satoshi 
Published: August 2010

AbstractWe successfully improved a merged diamond diode, namely a Schottky‐pn diode (SPND), which is composed of a fully depleted n‐type active layer sandwiched between a highly doped p+‐type layer and a Schottky metal. According to the analysis of operation mechanisms based on band diagrams, we increased the acceptor concentration in the p+‐type layer in order to decrease the on‐resistance (RonS), and increased the n‐type layer width to reach higher blocking voltage (Vblock). Consequently, much lower RonS of 0.03 mΩ cm2 and higher Vblock than those of the previously reported diamond SPND were achieved simultaneously. Thus, we elucidated experimentally that the diamond SPND has no trade‐off relationship between RonS and Vblock, and is suitable for low‐loss high‐power switching devices.
Effects of post‐growth annealing on physical properties of SrRuO3 thin film grown by MOCVD
Authors: Anooz S. Bin , Schwarzkopf J. , Dirsyte R. , Wagner G. , Fornari R. 
Published: August 2010

AbstractWe report on the annealing effects on strontium ruthenate thin films deposited on SrTiO3 using liquid‐delivery metalorganic chemical vapor deposition (MOCVD). The results of high resolution X‐ray diffraction (HR‐XRD), Raman spectroscopy, atomic force microscopy (AFM), and electrical resistivity, before and after a post‐growth annealing process were analyzed and compared. XRD and Raman spectroscopy for the as‐deposited film revealed that the film had c‐axis orientation and contained RuO2 as secondary phase. Single phase SrRuO3 could be obtained by annealing the film at 700 °C. Annealing at higher temperatures up to 850 °C leads to ruthenium deficiency, which is revealed by an increase in the out‐of‐plane lattice parameter, while at even higher annealing temperatures a decrease in the out‐of‐plane lattice parameter was detected might be due to diffusion of Ti from the substrate. The electrical resistivity increased with increasing annealing temperature up to 950 °C and showed typical metallic temperature dependence, while for the film annealed at 1000 °C a semiconductor‐like behavior was observed.
Integrated impedance based hydrocarbon gas sensors with Na‐zeolite/Cr2O3 thin film interfaces: Electrochemical mechanism of the impedance changes
Authors: Dubbe Andreas 
Published: August 2010

AbstractThis study aims to clarify the mechanism of a hydrocarbon gas sensor effect, which involves impedance changes of a Na+ ion conducting Pt‐doped zeolite layer in contact with chromia (Cr2O3) films as electrodes. Based on our previous studies on sensing characteristics and model experiments with asymmetrical cells, a coherent picture of the sensing mechanism is derived: The impedance change is attributed to the process of Na+ ion insertion from the zeolite into the chromia film. The impedance of this interface process is a function of the electrical potential at the interface. Combined with the observation that gas sorption in the zeolite micropores causes changes of the electrochemical potential at the zeolite surface, these two effects explain the observed sensor effect. The sensor response as predicted from this theory agrees well with the experimental data of the original sensor. Implications for the development of integrated devices are discussed.
Structural, electronic, linear, and nonlinear optical properties of ZnCdTe2 chalcopyrite
Authors: Ouahrani Tarik , Reshak Ali H. , Khenata R. , Baltache H. , Amrani B. , Bouhemadou A. 
Published: August 2010

AbstractWe report results of first‐principles density functional calculations using the full‐potential linearized augmented plane wave method. The generalized gradient approximation (GGA) and the Engel–Vosko‐GGA (EV‐GGA) formalism were used for the exchange–correlation energy to calculate the structural, electronic, linear, and nonlinear optical properties of the chalcopyrite ZnCdTe2 compound. The valence band maximum and the conduction band minimum are located at the Γ‐point, resulting in a direct band gap of about 0.71 eV for GGA and 1.29 eV for EV‐GGA. The results of bulk properties, such as lattice parameters (a, c, and u), bulk modulus B, and its pressure derivative B′ are evaluated. The optical properties of this compound, namely the real and the imaginary parts of the dielectric function, reflectivity, and refractive index, show a considerable anisotropy as a consequence ZnCdTe2 posseses a strong birefringence. In addition, the extinction coefficient, the electron energy loss function, and the nonlinear susceptibility are calculated and their spectra are analyzed.
Coefficient of thermal expansion of stacked auxetic and negative thermal expansion laminates
Authors: Lim Teik‐Cheng 
Published: August 2010

AbstractAnalytical expressions for the in‐plane and out‐of‐plane coefficients of thermal expansion for laminates with isotropic laminas are presented herein based on (i) zero net force on the laminate edges, (ii) equal displacement of the lamina edges, and (iii) Hooke's law in three dimensions. Results show that a laminate consisting of alternating auxetic (with positive coefficient of thermal expansion, CTE) and negative thermal expansion (NTE) (with positive Poisson's ratio) laminas exhibit a more negative effective CTE than a laminate of alternating conventional laminas (positive Poisson's ratio and positive CTE) with unconventional laminas (auxetic and NTE). Finally, temperature‐dependent CTE for such laminates are developed and plotted for special cases. It is herein shown that under certain circumstances, the magnitude of temperature‐dependent effective CTE tends to infinity.
Counterintuitive modulus from semi‐auxetic laminates
Authors: Lim T.‐C. , Rajendra Acharya U. 
Published: August 2010

AbstractSemi‐auxetic laminates consist of conventional and auxetic laminas such that the interlacing effect results in overall properties that are absent in both conventional and purely auxetic materials. Of late it has been shown that the in‐plane Young's modulus of a semi‐auxetic laminate always exceeds the rule of mixtures. In this paper, the conditions by which the in‐plane modulus exceeds the stiffness of the phase with higher modulus is established. In addition, an example is demonstrated whereby the maximum point of the in‐plane modulus occurs where the volume fraction of the stiffer phase is lower than that of the more compliant phase.
A simple theoretical approach to designing nanotube‐based sensors
Authors: Rocha C. G. , Ferreira M. S. 
Published: August 2010

AbstractNanotube‐based sensors are high‐sensitivity devices that can probe a number of nano‐sized impurities through doping‐induced variations in their conductivity. One key question for designing efficient sensors is to establish which impurity/nanotube combination will generate maximum sensitivity. Standard ways for selecting a good nanotube/impurity combination consists of an ad hoc approach that involves sifting through an immense universe of possibilities. This trial‐and‐error approach, despite being time‐consuming and computationally demanding, does not necessarily result in sensitivity optimization. A mathematically transparent theoretical formalism was adopted to introduce an inverse way of thinking about the nanotube/impurity combination by establishing a set of characteristics these components must have to generate high sensitivity devices. In this way guidelines were generated that can narrow the search for the ideal components of nanotube‐based sensors. We illustrate this method with a few examples of nanotubes doped with a different single‐atom impurities.
Role of non‐collinear magnetization: From ferromagnetic nanowires to quantum rings
Authors: Sedlmayr Nicholas , Dugaev Vitalii , Berakdar Jamal 
Published: August 2010

AbstractWe consider interaction effects related to a non‐uniform magnetization in ferromagnetic nanowires and their possible generalization to nanorings. First we show that the electric current in a ferromagnetic nanowire with more than one domain wall induces an exchange coupling between the walls mediated by the spin‐dependent interference of scattered carriers. This interaction reveals a complex behavior as a function of mutual orientations and separation of the domain walls, thus affecting the domain wall dynamics. Then we consider how the theory should be modified in the case of a magnetized quantum ring. In this case the situation is more complicated because the vortex and onion magnetization states in the ring are not truly ferromagnetic.
Electronic structure and magnetism of monatomic one‐dimensional metal nanostructures on metal surfaces
Authors: Ignatiev P. A. , Negulyaev N. N. , Niebergall L. , Hashemi H. , Hergert W. , Stepanyuk V. S. 
Published: August 2010

AbstractWe report on theoretical studies of one‐dimensional (1D) monatomic metal nanostructures coupled to metal substrates, which support surface states. The aim of the work is to demonstrate general features of electronic structure, magnetic properties, and interactions in such systems. We start from simple finite monatomic chains. It is shown that electronic confinement in 1D metallic chains can be observed at energies of projected band gaps of a metallic substrate. At other energies the confinement is significantly suppressed by scattering of chain states into the metallic substrate. Although this scattering decreases the exchange interaction between magnetic atoms incorporated into the chain, we show that it is still possible to get a significant enhancement of the exchange interaction in short chains. The next problem addressed in the paper is related to the interaction of the surface state with ad‐chains and 1D resonators. Special attention is paid to a possible impact of confinement in 1D resonators on atomic diffusion and self‐organization inside them. Finally, we illustrate the theoretical approach for the treatment of magnetization dynamics in 1D nanostructures.
Spin selective transport through Aharonov–Bohm and Aharonov–Casher triple quantum dot systems
Authors: Tosi Leandro , Aligia A. A. 
Published: August 2010

AbstractWe calculate the conductance through a system of three quantum dots (QDs) under two different sets of conditions that lead to spin filtering effects under an applied magnetic field. In one of them, a spin is localized in one QD, as proposed by Delgado et al. [Phys. Rev. Lett. 101, 226810 (2008)]. In the other one, all dots are equivalent by symmetry and the system is subject to a Rashba spin–orbit coupling. We solve the problem using a simple effective Hamiltonian for the low‐energy subspace, improving the accuracy of previous results. We obtain that correlation effects related to the Kondo physics play a minor role for parameters estimated previously and high enough magnetic field. Both systems lead to a magnetic field tunable “spin valve”.
Novel polyanion conduction in Sc2(WO4)3 type negative thermal expansion oxides
Authors: Zhou Yongkai , Neiman Arkady , Adams Stefan 
Published: August 2010

AbstractThe relationship between the polyatomic anion conduction and negative thermal expansion (NTE) in Sc2(WO4)3 type structure has been investigated by a combination of computational, electrochemical and X‐ray diffraction approaches. The motion of the effective charge carriers in solid‐state ionics can be visualised by molecular dynamics (MD) simulations if proper initial structure and force‐field are known. By successfully reproducing the NTE for a large temperature range, we have designed and verified a valid force‐field to predict the mobile species in Sc2(WO4)3. Using the same force‐field a series of correlated WO migrations are observed in extended isothermal–isobaric MD simulations. Tubandt‐type electrolysis experiments confirmed that the mobile species in Sc2(WO4)3 is anionic. Scandium tungstate is thus the prototype of novel class of ionic conductors, a WO anion conductors. The relationship of the ion transport in this unique ion conductors with polyatomic mobile charge carriers to the NTE is discussed.
In situ 3D X‐ray microtomography study comparing auxetic and non‐auxetic polymeric foams under tension
Authors: McDonald Samuel A. , Dedreuil‐Monet Ghislain , Yao Yong Tao , Alderson Andrew , Withers Philip J. 
Published: August 2010

AbstractX‐ray microtomography has been used to study in situ the uniaxial tensile response of low‐density polyurethane foam. Two variants have been examined, one before and one after treatment to generate auxetic behaviour. For both variants, microstructurally faithful finite element (FE) models have been constructed from the initial tomographs. For each variant a series of tomographs have been collected during progressive straining. Poisson's ratios of 0.30 (conventional, non‐auxetic) and −0.22 (auxetic) have been measured for the two variants by digital image correlation (DIC) between successive images. By comparison, the FE models exhibited Poisson's ratio's of 0.5 and −0.3, respectively. Key micromechanical mechanisms responsible for the auxetic effect have been observed during straining, such as the straightening of bent ribs and rotation of nodes (joints), compared to changes in the angles between essentially straight struts for the non‐auxetic variant. The microstructurally faithful FE models confirm the mechanisms observed in the experiments and enable characteristic rib and node behaviour to be followed in greater detail.
Anisotropy energy, spin‐atomic vibration interaction, and spin‐flip Hamiltonian of a single atomic spin system: application to iron ion
Authors: Kokado Satoshi , Harigaya Kikuo , Sakuma Akimasa 
Published: August 2010

AbstractWe derive an anisotropy energy VA, a spin‐atomic vibration interaction VSA, and a spin‐flip Hamiltonian VSF of a single atomic spin system, “Fe2+ (3d6) in a crystal field of tetragonal symmetry”. The perturbation theory is here applied to the system with the spin‐orbit interaction and the kinetic and potential energies, in which difference of vibration displacement between a nucleus and electrons is taken into account. We first find conditions to enhance a coefficient |D | of VA = – |D |S2Z, with SZ being the Z component of a spin operator. Second, the presence or absence of VSA and VSF is shown for any parameter sets. Also, some coefficients of VSA are proportional to 1/√f, with f being a vibration frequency, although a coefficient of the conventional spin‐phonon interaction has √f (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Highly luminescent nanostructures of CdS and ZnS prepared by microwaves heating: effect of sulphide concentration
Authors: Ortíz Samuel , Gómez Idalia , Elizondo Perla , Cavazos José 
Published: August 2010

AbstractNearly monodisperse and highly luminescent ZnS and CdS NPs were obtained by microwave irradiation. The ZnS and CdS NPs solutions were prepared by adding freshly prepared ZnSO4 or CdSO4 solution to a thioacetamide solution at pH 8 in the presence of sodium citrate in solution used as stabilizer. The precursors concentration were such that the sulphide ion concentrations were 3 × 10–2 M, 6 × 10–2 M and 8 × 10–2 M, for each of these [S] concentrations the [Zn] or [Cd] content were fixed at 3 × 10–2 M. NPs were prepared under microwave irradiation for 1 min at 905 W of power. The NPs samples were taken when the temperature descended to ambient temperature for further analysis. Effect of concentration of Cd and Zn ions were studied in the luminescence property. RXD, AFM, TEM and UV‐Vis were used too as analytical equipment for characterization. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of oscillator strength in colloidal CdSe/CdS dots‐in‐rods
Authors: Pisanello Ferruccio , Leménager Godefroy , Martiradonna Luigi , Spinicelli Piernicola , Fiore Angela , Amo Alberto , Giacobino Elisabeth , Cingolani Roberto , De Vittorio Massimo , Bramati Alberto 
Published: August 2010

AbstractThe oscillator strength in CdSe/CdS colloidal dot‐in‐rods is evaluated and assessed to be of ∼1.5. On the basis of this finding, the possibility to reach the strong coupling regime with photonic crystals nanocavities is discussed. In spite that carefully choosing the cavity parameters the strong coupling regime could be analytically achieved at room temperature, theoretical considerations show that the typical Rabi doublet cannot be resolved. The work draws also a viable strategy toward the observation of the strong coupling at cryogenic temperatures. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Collective electronic excitations in a potassium‐covered Be surface
Authors: Echeverry J. P. , Chulkov E. V. , Silkin V. M. 
Published: August 2010

AbstractWe investigate within a two‐component jellium model the collective electronic excitations in a one‐monolayer (1ML) potassium covered beryllium surface. The calculations of the surface dynamical response properties have been performed with one‐particle energies and wave functions derived from the Kohn‐Sham density‐functional theory. The dispersion relation for the surface plasmon modes as well as the real and imaginary parts of the induced dynamical charge density oscillations are presented. Comparison of the collective modes in the 1ML K/Be system with that of a clean Be surface is made. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)