bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivities to DMI fungicides in populations of Podosphaera fusca in south central Spain
Authors: López‐Ruiz Francisco J , Pérez‐García Alejandro , Fernández‐Ortuño Dolores , Romero Diego , García Emilio , de Vicente Antonio , Brown James KM , Torés Juan A 
Published: March 2010

AbstractBACKGROUND: Cucurbit powdery mildew elicited by Podosphaera fusca (Fr.) U Braun & N Shishkoff limits crop production in Spain. Disease control is largely dependent on fungicides such as sterol demethylation inhibitors (DMIs). Fungicide resistance is an increasing problem in this pathogen. To overcome such risk, it is necessary to design rational control programmes based upon knowledge of field resistance. The aim of this study was to investigate the state of DMI sensitivity of Spanish P. fusca populations and provide tools for improved disease management.RESULTS: Using a leaf‐disc assay, sensitivity to fenarimol, myclobutanil and triadimenol of 50 isolates of P. fusca was analysed to determine discriminatory concentrations between sensitive and resistant isolates. As no clearly different groups of isolates could be identified, discriminatory concentrations were established on the basis of maximum fungicide field application rate, 100 mg L−1 for the three fungicides tested. Subsequently, a survey of DMI resistance was carried out in different provinces located in the south central area of Spain during the cucurbit growing seasons in 2002, 2003 and 2004. Examination of a collection of 250 isolates revealed that 23% were resistant to fenarimol and 7% to triadimenol, the provinces of Almería, Badajoz and Murcia being the locations with the highest frequencies of resistance. By contrast, no resistance to myclobutanil was found.CONCLUSION: Results show that fenarimol and, to a lesser extent, triadimenol have become less efficient for controlling cucurbit powdery mildew in Spain. These are important observations that should lead to reconsideration of the current disease management programmes. Copyright © 2010 Society of Chemical Industry
Atomic interactions and hydrogen‐induced γ* phase in fcc iron–nickel alloys
Authors: Movchan D. N. , Shyvanyuk V. N. , Shanina B. D. , Gavriljuk V. G. 
Published: March 2010

AbstractEnergy of metal–metal (Me–Me) and metal–hydrogen (Me–H) bonds in hydrogen‐free and hydrogen‐charged fcc iron, nickel, and iron–nickel alloys are ab initio calculated. It is shown that short‐range decomposition of Fe–Ni solid solution and difference in Fe–H and Ni–H bonds are responsible for splitting of γ reflections in the X‐ray diffraction patterns, which is at variance with the common interpretation in terms of a hydrogen‐caused γ* phase. X‐ray diffraction measurements confirm the absence of miscibility gap in the FeNi–H solid solution and its occurrence in Ni–H. Results of calculations are consistent with the absence of H–H pairs in pure nickel.
Inhomogeneities of InGaN/GaN MOVPE multi quantum wells grown with a two temperatures process studied by transmission electron microscopy
Authors: Kret S. , Ivaldi F. , Sobczak K. , Czernecki R. , Leszczyński M. 
Published: March 2010

AbstractThe structural investigation of InGaN/GaN:Si multiple quantum well (MQW) samples grown by low‐pressure metal‐organic vapor phase epitaxy (LP‐MOVPE) in a two temperatures (2T) process on high‐pressure GaN mono‐crystalline substrates is performed by transmission electron microscopy (TEM). A sample in which barriers and wells were grown at 780 °C is compared with another in which the barriers were deposited at 900 °C and the wells at 730 °C. For both samples the indium composition in the QWs reaches the level of about 20 at.%. The local indium composition was measured through strain measurements by digital processing from the lattice fringes images taken by TEM. Cross‐sectional investigations are performed in two zone axes – [$1\bar {1}00$] and [$11\bar {2}0$] – with the use of axial and off‐axis illumination. During TEM investigations the formation of “false indium clusters ” of the size of 2–4 nm was observed for both samples just after 2 min of LaB6 electron beam illumination at 200 kV. Large lateral fluctuations of indium content in the QWs of the length of 30–130 nm were detected in 2T sample. The plan view analysis was carried out to characterize the anisotropy of the indium fluctuation inside the QWs.
In‐vacancies in Si‐doped InN
Authors: Rauch C. , Reurings F. , Tuomisto F. , Veal T. D. , McConville C. F. , Lu H. , Schaff W. J. , Gallinat C. S. , Koblmüller G. , Speck J. S. , Egger W. , Löwe B. , Ravelli L. , Sojak S. 
Published: March 2010

AbstractThe introduction of vacancy type point defects by Si doping in InN grown by plasma‐assisted molecular beam epitaxy was studied using a monoenergetic positron beam. With the combination of positron lifetime and Doppler broadening measurements, compensating In‐vacancy (VIn) acceptors were identified in the material. For increasing Si doping an enhanced formation of VIn defects was observed, up to a concentration of $c_{\rm V} = 7 \times 10^{17} \,{\rm cm}^{ - 3} $ in the highest doped sample ($n_{\rm e} = 6.6 \times 10^{20} \,{\rm cm}^{ - 3} $). A strong inhomogeneity of the defect profile with a significant increase of the VIn concentration toward the layer/substrate interface could be detected. Additionally, larger vacancy clusters containing several VIn are formed in the proximity of the interface.
A study on oxygen reduction inhibition at pyridine‐terminated self assembled monolayer modified Au(111) electrodes
Authors: Muglali Mutlu Iskender , Bashir Asif , Rohwerder Michael 
Published: March 2010

AbstractThe electroreduction of oxygen on self‐assembled monolayers (SAMs) of various pyridinedisulfides and pyridinethiols on Au(111) surfaces has been investigated in alkaline solutions. Electrochemical experiments that were carried out in three‐electrode cell reveal a good correlation between the chain‐length of thiol molecules and the oxygen reduction inhibition of the resulting adlayer films. The effect of retarded diffusion of oxygen through the protective film has been investigated by forming additional layer of immobilized cytochrome c (cyt.c) metalloprotein on pyridine moiety during linear sweep voltammetry (LSV) scans. At sufficiently negative cathodic potentials the electrochemical reaction rate has been observed to increase together with the density of defects. Morphological changes at different levels of cathodic polarization were investigated by ex situ scanning tunneling microscopy (STM), indicating oxygen reduction reaction (ORR) induced structural defects at the metallorganic interface.
Theory of carrier and photon dynamics in quantum dot light emitters
Authors: Dachner Matthias‐René , Malic Ermin , Richter Marten , Carmele Alexander , Kabuss Julia , Wilms Alexander , Kim Jeong‐Eun , Hartmann Gregor , Wolters Janik , Bandelow Uwe , Knorr Andreas 
Published: March 2010

AbstractWe present a microscopic theory describing the charge carrier and light emission dynamics in quantum dot (QD) light emitters. The theory covers non‐classical light emission (fluorescence and Raman emission) in the low carrier injection limit as well as laser emission and pulse amplification in the high carrier injection limit. The theoretical approach is based on QD Bloch equations including microscopically calculated Coulomb and electron–phonon scattering rates between bound QD, continuous wetting layer (WL) and bulk states. In the low carrier density limit, multi‐phonon relaxation is the dominant process, while at high charge carrier densities, Coulomb scattering dominates the dynamics. Using an equation of motion approach, we address (i) time‐resolved fluorescence and Raman emission, (ii) electrical injection and charge carrier transfer from bulk into WL and QD states, (iii) single photon emission and (iv) gain dynamics of QD amplifiers and lasing dynamics in QD vertical‐cavity surface‐emitting lasers (VCSELs) at high injection currents.
Near‐field scanning optical microscopy of colloidal CdSe nanowires
Authors: Mintairov Alexander M. , Herzog Joseph , Kuno Masaru , Merz James L. 
Published: March 2010

AbstractWe have developed a nano‐optical technique using diffraction‐limited far‐field fluorescence monitoring of near‐field scanning optical microscopy (NSOM) experiments. The technique was combined with time‐resolved (TR) spectroscopy and was used to study the emission properties of single colloidal CdSe nanowires (NWs) with spatial resolution ∼100 nm. The use of this novel technique reveals a critical role of organic suspensions in optical experiments with single colloidal nanostructures. We observed that organic suspensions form a viscous shell which acts as a nano‐lens providing efficient coupling of excited and emitted photons to the NW. We demonstrate that physical distortion of the shell produced by the near‐field probe affects the emission dynamics of single NWs. Temperature dependent measurements show that the emission decay of a colloidal NW is dominated by size‐dependent non‐radiative recombination.
Self‐organized nucleation layer for the formation of ordered arrays of double‐walled TiO2 nanotubes with temperature controlled inner diameter
Authors: Enachi Mihai , Tiginyanu Ion , Sprincean Veaceslav , Ursaki Veaceslav 
Published: March 2010

AbstractIt is proposed to use the variation of the electrolyte temperature to fabricate titania nanotubes with variable inner diameter at a constant outer diameter and an invariable package density. The anodization of Ti sheets in an ethylene glycol and HF containing electrolyte is found to allow the preparation of nanotubes with the inner diameter controlled in the range from 10 nm to more than 250 nm through the change of the electrolyte temperature from –20 °C to +50 °C. The peculiarities of the anodization process performed at low electrolyte temperatures are discussed.magnified image(© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of phosphorus, arsenic or antimony ion implantation in silicon targets
Authors: Labbani R. 
Published: March 2010

AbstractThe aim of this work was to study the behaviors of P+, As+ and Sb+ ions implanted in silicon targets. The investigation was mainly performed by simulation using the SRIM2006 (stopping and range of ions in matter) program. Several quantities, such as the depth profiles of the ion concentration, stopping powers and radiation damage, were predicted. Besides, an experimental study was carried out particularly for the case of Sb+ ions. The antimony ion implantation was performed to a dose of 5 × 1015 Sb+ cm−2 at 120 keV energy into an Si(100) target. The samples were analyzed by means of Rutherford backscattering spectroscopy (RBS) using He+ particles. A discrepancy between the experimental and simulated antimony depth profiles was revealed. In the case of phosphorus and arsenic, the simulated projected ranges (Rps) were compared with literature values and good agreement has been obtained. Finally, it is necessary to note that the predictions of some effects related to ion implantation (annealing temperature, crystallographic orientation of the targets, multi‐implantations, etc.) are not possible via the SRIM code. Copyright © 2010 John Wiley & Sons, Ltd.
Observation of self‐assembled monolayers on diamond‐like carbon films: agglomeration of self‐assembled FDTS molecules
Authors: Choi Junho , Sakurai Kenichi , Kato Takahisa 
Published: March 2010

AbstractSelf‐assembled monolayers (SAMs) of 1H,1H,2H,2H‐perfluorodecyltrichlorosilane (FDTS) were prepared on hydrogen‐free diamond‐like carbon (DLC) films by immersing the DLC substrates into dilute solutions of FDTS in hydrofluoroether. The FDTS‐adsorbed DLC surfaces were observed using a tapping mode atomic force microscopy (AFM) with respect to the immersion time to investigate the monolayer formation process. The measurements of the water contact angles, X‐ray photoelectron spectroscopy (XPS) and the surface roughness were also conducted. The DLC films were deposited on silicon plates with an electron cyclotron resonance(ECR)‐type ion beam sputter using graphite as a sputter target. Initially, FDTS molecules form a liquid‐like disordered mass of molecules on the DLC surface, and then begin to form densely packed FDTS islands with the height of a monolayer. The FDTS monolayer islands grow laterally with the immersion time. After immersion for several hours, the agglomeration of FDTS molecules to a height of 3–5 nm is observed on the DLC surfaces. This is due to the presence of a large number of active sites on the hydrogen‐free DLC surface, preventing the surface diffusion of FDTS molecules. Also, the inhomogeneity of the DLC surface due to the adsorption of a large number of oxygen atoms from the air after DLC deposition is one of the reasons for the FDTS agglomeration. Copyright © 2010 John Wiley & Sons, Ltd.
Photoelectrochemical and photocatalytic properties of mesoporous TiO2 films modified with silver and gold nanoparticles
Authors: Smirnova N. , Vorobets V. , Linnik O. , Manuilov E. , Kolbasov G. , Eremenko A. 
Published: March 2010

AbstractTiO2 and Zn2+/TiO2 functional coatings doped with Ag or Au nanoparticles were prepared by photo‐ or thermoreduction of metal ions introduced into bulk or adsorbed on the film surface. TiO2 and Zn2+/TiO2 films with the Ag or Au nanoparticles (MNPs) distributed in the matrix and on the surface were characterized by XRD, TEM and UV‐Vis spectroscopy. Direct photoelectrochemical investigations of the M/TiO2 and M/Zn2+/TiO2 heterojunctions showed the cathodic shift of the flatband potential position and the increase of photocurrent quantum yield in comparison with unmodified TiO2 electrodes. Photocatalytic activity of synthesized films estimated in the process of degradation of the antibiotic tetracycline hydrochloride coincides with photoelectrochemical data. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of pH variation in aqueous solutions on dissolution of copper oxide
Authors: Ko Cheon Kwang , Lee Won Gyu 
Published: March 2010

AbstractDissolution characteristics, such as the solubility of copper oxides and the complexation stability between copper ions and aqueous solutions, were analyzed under various pH values of citric acid or monoethanolamine (MEA) aqueous solution, which are known as complexing agents for copper. The dissolution characteristics of the aqueous solutions were measured in terms of the solubility of copper oxides and metallic copper. The citric acid solution had a good solvent property for copper oxides in the range of acidic conditions, whereas the MEA solution showed the same property in the basic region. The surface roughness of copper film treated with solutions having different pH values strongly depended on the solubility of copper oxides. The treatment of citric acid and MEA of different pH values has an influence on the oxidation status of copper surface, which is confirmed with X‐ray photoemission spectroscopy and electrochemical impedance. Copyright © 2010 John Wiley & Sons, Ltd.
Microstructural surface changes of electrodeposited Pb on gas diffusion electrode during electroreduction of gas‐phase CO2
Authors: Machunda Revocatus L. , Lee JongGyu , Lee Jaeyoung 
Published: March 2010

AbstractWe have applied zero‐gap cell for gas‐phase CO2 conversion to introduce better applicability at large scale. The cathodic reduction of CO2 has attracted considerable attention with the aim of generating useful fuels and chemicals. The CO2 gas is reduced on the surface of the electrodeposited Pb on gas diffusion electrode to give mainly formic acid, accompanied by morphological and crystalline changes of the catalyst. These changes are revealed by both scanning electron microscope and X‐ray diffraction analysis. The catalytic conversion of CO2 gas as a function of Pb microstructures in relation to formic acid production was also investigated and is presented. Copyright © 2010 John Wiley & Sons, Ltd.
Formation of multi‐layered inorganic film on polycarbonate surface modified by an atmospheric plasma discharge
Authors: Won Dong Su , Kim Tea Kyung , Lee Won Gyu 
Published: March 2010

AbstractSurface modification of polymers has been widely studied because of the industrial interest in several applications involving adhesion, packaging and metallization, among others. Plasma treatment, particularly atmospheric pressure plasma, is one of the most versatile techniques in surface modification. In this work, atmospheric pressure plasma treatment was performed to modify a polycarbonate surface. The effects of the treatment were sensitive to both the plasma ambient and the time elapsed after treatment. Surface treatment with a dielectric barrier discharge plasma torch produced an increase in the wettability of polycarbonate through the creation of COH polar groups on its surface, together with surface roughness. These effects were more pronounced by the addition of oxygen in an Ar gas mixture and the surface treatment time. In general, the atmospheric plasma torch treatment helped to enhance the wettability of the aqueous solutions to form a multi‐layered inorganic film on the polycarbonate. Copyright © 2010 John Wiley & Sons, Ltd.
Temperature‐dependent profile of the surface states and series resistance in (Ni/Au)/ AlGaN/AlN/GaN heterostructures
Authors: Taşçıoǧlu İ. , Aydemir U. , Şafak Y. , Özbay E. 
Published: March 2010

AbstractThe profile of the interface state densities (Nss) and series resistances (Rs) effect on capacitance–voltage (C–V) and conductance‐voltage (G/ω–V) of (Ni/Au)/AlxGa1−xN/AlN/GaN heterostructures as a function of the temperature have been investigated at 1 MHz. The admittance method allows us to obtain the parameters characterizing the metal/semiconductor interface phenomena as well as the bulk phenomena. The method revealed that the density of interface states decreases with increasing temperature. Such a behavior of Nss can be attributed to reordering and restructure of surface charges. The value of series Rs decreases with decreasing temperature. This behavior of Rs is in obvious disagreement with that reported in the literature. It is found that the Nss and Rs of the structure are important parameters that strongly influence the electrical parameters of (Ni/Au)/AlxGa1−xN/AlN/GaN(x = 0.22) heterostructures. In addition, in the forward bias region a negative contribution to the capacitance C has been observed, that decreases with the increasing temperature. Copyright © 2010 John Wiley & Sons, Ltd.
A comparative X‐ray photoelectron spectroscopy and medium‐energy ion‐scattering study of ultra‐thin, Hf‐based high‐k films
Authors: Sygellou L. , Ladas S. , Reading M. A. , van den Berg J. A. , Conard T. , De Gendt S. 
Published: March 2010

AbstractUltra‐thin high‐k layers based on HfO2, or Hf‐silicates in combination with sub‐nanometer SiO2, show much promise in their use as Si‐compatible gate dielectrics. XPS has been applied on a range of HfO2/SiO2 and HfSiOx(60%Hf)/SiO2 films on Si(100), before and after decoupled plasma nitridation (DPN) at 1073 K. The treatment of the data was optimized in order to determine individual layer thicknesses of the multilayer stack taking into account the measured nitrogen content of the nitrided films. The procedure adhered to the prescriptions of ISO18118:2004(E) for the calculations of inelastic mean free paths (IMFP) and elastic corrections thereof, using film material properties, like densities and band gaps. Effective attenuation lengths (EAL) were taken throughout as 90% of the respective IMFP, whereas an appropriate set of empirical relative sensitivity factors (RSF) was used. The XPS‐derived thicknesses were compared with corresponding values obtained from medium‐energy ion scattering (MEIS) measurements on the same series of specimens in combination with energy spectrum simulation to provide quantitative layer information with sub‐nanometer resolution. The XPS and MEIS results exhibit very good agreement on the deduced layer structures within the respective experimental uncertainty, and both sets are consistent with the grown nominal layer parameters of the high‐k nanofilms. Copyright © 2010 John Wiley & Sons, Ltd.
XPS depth profiling of polystyrene etched by electrospray droplet impact
Authors: Sakai Yuji , Iijima Yoshitoki , Asakawa Daiki , Hiraoka Kenzo 
Published: March 2010

AbstractThe molecular‐level depth profiling of polystyrene (PS) has been performed by using a newly designed electrospray droplet impact (EDI) gun. The multiple charged water droplets with kinetic energy of ∼106 eV were irradiated to a bulk and a spin‐coated PS. When a PS target is etched by EDI, the ablation of the sample is suppressed to minimal, i.e. the shallow surface etching with nonrecognizable damage on the surface is realized. It was found that XPS spectra for PS were independent on the irradiation time by EDI. This indicates that EDI is a unique technique for the surface etching of synthetic polymer materials without resulting in any damage to the etched surface. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of different P/As ratio on the optical and structural properties of GaAs1−xPx/GaAs
Authors: Cetin Saime S. , Kinaci Baris , Asar Tarık , Kars Ilknur , Ozturk Mustafa K. , Mammadov Tofig S. , Ozcelik Suleyman 
Published: March 2010

AbstractThe GaAs1−xPx/GaAs ternary alloys were grown on n‐GaAs (100) substrate with different P/As flux ratio by solid source molecular beam epitaxy (MBE) system using GaP decomposition source. In order to obtain smooth interface and lattice mismatch structures we have used both continuous growth (CG) and graded growth (GG) methods. The range of lattice parameters in the graded epilayer and phosphorous composition in the samples were determined by the high‐resolution X‐ray diffraction (HRXRD) rocking curve simulation. The critical energy points of the interband transition edges of the structures were determined by line‐shape analyses on their dielectric functions (DF) using spectroscopic ellipsometry (SE) measurements at a room temperature in the 0.5–5 eV photon energy region. Also, surface and interface phenomenon of the structures were discussed by using ellipsometric data. Phosphorous compositions of the ternary alloys were also calculated by photoluminescence (PL) emission peak positions at room temperature and using the bowing parameter obtained by fitting to critical points. Copyright © 2010 John Wiley & Sons, Ltd.
Probing soft materials with energetic ions and molecules: from microscopic models to the real world
Authors: Delcorte A. , Bertrand P. , Garrison B. J. , Hamraoui K. , Mouhib T. , Restrepo O. A. , Santos C. N. , Yunus S. 
Published: March 2010

AbstractAfter introducing a typical example of the performance of C60 clusters for the molecular depth‐profiling analysis of (bio‐)organic samples by secondary ion mass spectrometry (SIMS), this contribution reviews a few areas in which microscopic models using molecular dynamics (MD) simulations provide a better understanding and predictions in the field of organic sample sputtering. The topics considered discuss about structural effects in crystalline hydrocarbons, the sputtering of hybrid metal–organic surfaces and the influence of the cluster projectile size on molecular desorption and fragmentation. The next section of the article presents experimental studies using real‐world samples taken from technological applications in materials science to illustrate some of the strengths and weaknesses of molecular analysis and imaging of organic and biological samples by SIMS. Connections with the results of the simulations are pointed out when it is deemed appropriate. Copyright © 2010 John Wiley & Sons, Ltd.