bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spin relaxation and domain wall dynamics in glass‐coated microwires
Authors: Sossmeier K. D. , Beck F. , Chiriac H. , Schelp L. F. , Carara M. 
Published: February 2009

AbstractThe dynamic properties of the magnetic domain walls in amorphous glass‐covered microwires were studied. The samples was Joule annealed with an alternate current at different frequencies and the dynamic behaviour of the samples were studied at different applied stresses. The Landau–Lifshitz–Gilbert damping parameter and the domain wall mobility have shown that the dynamic response can be improved by increasing the annealing current frequency. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coulomb effects in type‐II Ga(As)Sb quantum dots
Authors: Gradkowski Kamil , Ochalski Tomasz J. , Williams David P. , Healy Sorcha B. , Tatebayashi Jun , Balakrishnan Ganesh , O'Reilly Eoin P. , Huyet Guillaume , Huffaker Diana L. 
Published: February 2009

AbstractWe present a detailed explanation of the blue‐shift that is observed in Ga(As)Sb quantum dots (QD) with increasing pump power density by employing an 8‐band k · p model with the Coulomb attractive potential added into the Hamiltonian. Two types of structures are considered: Ga(As)Sb QDs in a GaAs matrix and the same dots overgrown with an InGaAs quantum well (QW). We show that with increasing charge density the electron and hole energy levels shift relative to each other, which results in an increase of the optical transition energy (i.e. a blue‐shift). The major contribution to the effect arises from the holes and is a result of their 3D confinement inside the dot. Additionally, with increasing charge density the electrons move closer to the dot, which improves the oscillator strength of the ground‐state optical transition. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of electronic and transport properties of resonant triple quantum dot molecules
Authors: Shim Y.‐P. , Delgado F. , Korkusinski M. , Gaudreau L. , Studenikin S. , Kam A. , Sachrajda A. S. , Hawrylak P. 
Published: February 2009

AbstractWe present a theory of electronic and transport properties of triple quantum dot molecules in the vicinity of quadruple points where four different charge configurations are on resonance. We study three different quadruple points in the presence of a magnetic field and show that a trapped particle in one of the dot plays an essential role in determining the spin character of the transport. Many‐electron states of the triple quantum dot molecules are used as transport channels in the Fermi's Golden Rule approach and it is demonstrated that the Aharonov–Bohm oscillations of the energy spectrum lead to spin‐selective oscillations in transport. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐inverted electron–hole alignment in InAs/InP self‐assembled quantum dots
Authors: Reimer M. E. , Dalacu D. , Lapointe J. , Poole P. J. , McKinnon W. R. , Williams R. L. 
Published: February 2009

AbstractPhotoluminescence from individual InAs/InP quantum dots embedded within a planar n–i structure is studied as a function of vertical electric field. We demonstrate control of the electron number and determine the Stark shift and built‐in dipole at zero electric field. In contrast to the well studied InAs/GaAs quantum dot material system, we obtain a built‐in dipole which indicates that the electron lies above the hole at zero electric field. The magnitude and direction of the measured dipole suggests a uniform quantum dot composition. The gating principles we demonstrate can be applied to pre‐positioned InAs/InP quantum dots, such that arrays of initialized single spins can be employed for quantum information applications. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of ethanol in an inorganic salt detector based on porous silicon
Authors: Murillo N. , Rucavado E. , Ramírez‐Porras A. 
Published: February 2009

AbstractA porous silicon (PSi) chemical sensor for detection of chloride ions in aqueous solution is reported. The sensor setup is based on the semiconductor/electrolyte system used for the analysis of semiconductor surfaces. AC frequency response signals have been obtained in non‐ethanoic and ethanoic solutions containing small concentrations of chloride ions. Discussion of the results is provided. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemical etching of Si by Ag nanocatalysts in HF‐H2O2: application to multicrystalline Si solar cell texturisation
Authors: Bastide Stéphane , Quang Nam Le , Monna Rémi , Lévy‐Clément Claude 
Published: February 2009

AbstractMetal‐assisted chemical etching (MAE) was used as an alternative route to texturise the front surface of multicrystalline Si solar cells. Ag nanoparticles deposited by an electroless method on the Si surface acted as catalysts for Si etching in a solution containing HF and H2O2, an oxidizing species. MAE formed a duplex structure at the surface of the Si wafer consisting in a mesoporous Si layer that after dissolution in NaOH revealed the second structure, which is a macrotexturised surface. After texturisation, the effective reflectivity (AM1.5G, 400‐1000 nm) ranged between 12% and 15% depending on the duration of the dissolution treatment of the mesoporous layer. MAE texturised solar cells were compared to NaOH texturised solar cells made with similar wafers (∼25% in effective reflectivity). MAE texturisation leads to a gain in fill factor (FF) but not in short‐circuit current (JSC) (from average values). The best MAE cell exhibited higher JSC (+2%) and efficiency (16.1%) compared to the best NaOH cell (15.7%). (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detecting amine vapours with thermally carbonized porous silicon gas sensor
Authors: Björkqvist Mikko , Salonen Jarno , Tuura Jaani , Jalkanen Tero , Lehto Vesa‐Pekka 
Published: February 2009

AbstractA capacitive type porous silicon based gas sensor for detecting amine vapours has been developed. The sensor is highly sensitive, e.g., to methylamine and trimethylamine vapours, and its electrical parameters recover totally after exposure to studied gases. Thermal carbonization of porous silicon under acetylene atmosphere was carried out to produce stable and attractive surface to amine vapours. The sensor response to studied amine vapours can be separated from its response to humidity changes since their electrical responses act reversely. In addition to the vapours of methylamine/water and trimethylamine/water solutions, the sensor was also used to detect different amines, which are generated during spoilage of raw shrimps and Baltic herring fillets at room temperature. Fourier Transform Infrared spectroscopy was used to detect the amine vapours and other volatile compounds simultaneously with sensor measurements. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stress induced one‐dimensional model for current oscillations at the Si/electrolyte contact
Authors: Grzanna Jürgen , Notz Thilo , Lewerenz Hans‐J. 
Published: February 2009

AbstractA cellular automata is introduced to model the locally resolved oxide thickness, the stress, and the etching rate dynamics at the silicon electrolyte contact along a macroscopically long line (1 mm). Short‐ and long‐range interaction mechanisms are considered to achieve current oscillations. Extended chronoamperometric oscillations are obtained but finally, the oscillations become increasingly damped for the case of a locally acting stress and a locally varying etching rate. The additional incorporation of a small oscillating and long‐range interacting nominal etching rate into the model leads to sustained oscillations. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In‐situ FFT impedance spectroscopy in new modes applied to pore growth in semiconductors
Authors: Carstensen Jürgen , Föll Helmut , Cojocaru Ala , Leisner Malte 
Published: February 2009

AbstractMajor progress in FFT impedance spectroscopy now allows in‐situ measurements during pore growth in three modes, two of which use modulation of the back side or front side illumination intensity, respectively; with the back side illumination mode being especially useful to n‐macro(bsi) pores in Silicon. The data obtained in all modes can be interpreted on the base of fully quantitative models which give perfect fits to the measured data and therefore allow to extract in‐situ data of many parameters, including the valence of the process and the actual pore depth. Based on this, macropore growth in Si has been re‐investigated, resulting in new growth modes and especially in substantially increased macropore growth rates as well as pore quality. It is now possible to grow macropores in n‐type Si far deeper and more than twice as fast compared to the present state of the art; the quality as expressed, e.g., in the pore wall roughness, can also be substantially improved. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast macropore growth in n‐type silicon
Authors: Cojocaru Ala , Carstensen Jürgen , Ossei‐Wusu Emmanuel K. , Leisner Malte , Riemenschneider Oliver , Föll Helmut 
Published: February 2009

AbstractDeep macropores can be grown in classical aqueous HF electrolytes only at slow etching speeds, fast macropores can only be grown to modest depths (150 μm). The addition of acid acetic to the electrolyte can roughly double the etching speed of the macropores, enabling quick and easy etching of pore depths as deep as 520 μm, and potentially more, if wafers thicker than 550 μm would be used. The addition of carboxymethylcellulose sodium salt (CMC) to the electrolyte decreases the roughness of the pore walls significantly. It is successfully shown that electrolytes consisting of HF + acetic acid + CMC can be utilized to produce fast, deep, and smooth macropores simultaneously in n‐type silicon, required for a multitude of potential applications. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exploring the QSAR of Pyrazolo[3,4‐b]Pyridine, Pyrazolo[3,4‐b]Pyridone and Pyrazolo[3,4‐b]Pyrimidine Derivatives as Antagonists for A1 Adenosine Receptor
Authors: Cichero Elena , Casolino Chiara , Menozzi Giulia , Mosti Luisa , Fossa Paola 
Published: February 2009

AbstractPyrazolo[3,4‐b]pyridines have been recently presented as a novel class of adenosine A1 receptor antagonists. Depending on substitutions on some key positions of their scaffold they show selectivity towards A1, A2A or A3 receptors, which results in a variety of therapeutic potentialities of these ligands. In this work, we present a QSAR study on these analogues as antagonists for adenosine A1 receptors. Using the MOE software we identified a pool of descriptors that numerically describes the ligand features impacting the affinity at adenosine A1 receptors. The obtained information is useful to understand the main structural features that strongly correlate with the A1 antagonism in this class of compounds and will be used for the rational design of more potent and selective pyrazolo[3,4‐b]pyridine derivatives.
Combined utilization of ion mobility and ultra‐high‐resolution mass spectrometry to identify multiply charged constituents in natural organic matter
Authors: Gaspar Andras , Kunenkov Erast V. , Lock Richard , Desor Michael , Perminova Irina , Schmitt‐Kopplin Philippe 
Published: February 2009

AbstractNatural organic matter as complex biogeochemical non‐repetitive material was investigated with ion mobility mass spectrometry (IMS) and ultra‐high‐resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR‐MS) approaches in order to unravel the existence of multiply charged state constituents. Hereby we describe and assign the potential molecular formulae of these doubly charged species, derived from FTICR‐MS, and the existence of these species was confirmed via IMS. The parallel application of these powerful techniques enabled the boundaries of the understanding of natural organic matter to be pushed further. Copyright © 2009 John Wiley & Sons, Ltd.
First application of the depth profile of silica species as a tracer by fast‐atom bombardment mass spectrometry: investigation of the circulation of seawater and silica uptake by diatoms
Authors: Tanaka Miho , Takahashi Kazuya , Urabe Tatsuya , Oikawa Tomohiro , Nemoto Masao , Nagashima Hideki 
Published: February 2009

AbstractSilica, represented by SiO2, is the general name for the compounds composed of Si, O and H with their derivative complexes. Silica forms various chemical species in aquatic solutions, such as a monomer (Si(OH)3O−), dimer (Si2(OH)5O), and others. These species are known to vary in their relative abundances in solution depending on the chemical and physical conditions. Silica species dissolved in seawater have been examined by fast‐atom bombardment mass spectrometry (FAB‐MS) to elucidate the behavior of silica and its circulation as a novel tracer reflecting the chemical and physical conditions of seawater and the bioactivity of diatoms, which take up silica. In the seawater of Tokyo Bay, silica species such as [Si(OH)2O2Na]− ([monomer–Na]−), [Si2(OH)5O2]− ([dimer]−), [Si2(OH)4O3Na]− ([dimer–Na]−), [Si4(OH)7O5]− ([cyclic tetramer]−), [Si4(OH)6O6Na]− ([cyclic tetramer–Na]−), [Si4(OH)9O4]− ([linear tetramer]−) and [Si4(OH)8O5Na]− ([linear tetramer–Na]−) were observed and assigned by FAB‐MS. To investigate the suitability of silica species as a tracer, the relative peak intensity ratios of silica species observed in the mass spectra, i.e. the profiles of the ratio of the linear tetramer to the cyclic tetramer (m/z 329/311) and the ratio of the dimer to the cyclic tetramer (m/z 173/311) against depth, were examined to determine the annual changes and reproducibility of the depth profiles. In particular, the depth profile of the relative ratio of the linear tetramer to the cyclic tetramer, 329/311, exhibits critical changes depending on the seawater budget. These changes in the relative ratios were identified by an experiment involving a simple sodium chloride solution system. Our measurement is expected to elucidate the dynamics of silica and its role as ‘food’ for diatoms, and we showed that speciation using mass spectrometry is a powerful tool for examining elemental behavior in nature and environmental changes. Our results suggest that a silica tracer is useful for investigating the behavior of seawater in small coastal regions and the uptake of silica by diatoms. Copyright © 2009 John Wiley & Sons, Ltd.
Analysis of Steiner subtrees of random trees for traceroute algorithms
Authors: Guillemin Fabrice , Robert Philippe 
Published: February 2009

AbstractWe consider in this article the problem of discovering, via a traceroute algorithm, the topology of a network, whose graph is spanned by an infinite branching process. A subset of nodes is selected according to some criterion. As a measure of efficiency of the algorithm, the Steiner distance of the selected nodes, i.e. the size of the spanning subtree of these nodes, is investigated. For the selection of nodes, two criteria are considered: a node is randomly selected with a probability, which is either independent of the depth of the node (uniform model) or else in the depth biased model, is exponentially decaying with respect to its depth. The limiting behavior the size of the discovered subtree is investigated for both models. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Linear lower bounds for δc(p) for a class of 2D self‐destructive percolation models
Authors: van den Berg J. , de Lima B.N.B. 
Published: February 2009

AbstractThe self‐destructive percolation model is defined as follows: Consider percolation with parameter p > pc. Remove the infinite occupied cluster. Finally, give each vertex (or, for bond percolation, each edge) that at this stage is vacant, an extra chance δ to become occupied. Let δc(p) be the minimal value of δ, needed to obtain an infinite occupied cluster in the final configuration. This model was introduced by van den Berg and Brouwer. They showed, for the site model on the square lattice (and a few other 2D lattices satisfying a special technical condition) that δc(p) ≥ ${(p-p_{c})\over {p}} $. In particular, δc(p) is at least linear in p − pc.Although the arguments used by van den Berg and Brouwer look very lattice‐specific, we show that they can be suitably modified to obtain similar linear lower bounds for δc(p) (with p near pc) for a much larger class of 2D lattices, including bond percolation on the square and triangular lattices, and site percolation on the star lattice (or matching lattice) of the square lattice. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Cytochrome c on Silica Nanoparticles: Influence of Nanoparticle Size on Protein Structure, Stability, and Activity
Authors: Shang Wen , Nuffer Joseph H. , Muñiz‐Papandrea Virginia A. , Colón Wilfredo , Siegel Richard W. , Dordick Jonathan S. 
Published: February 2009

AbstractThe structure, thermodynamic and kinetic stability, and activity of cytochrome c (cyt c) on silica nanoparticles (SNPs) of different sizes have been studied. Adsorption of cyt c onto larger SNPs results in both greater disruption of the cyt c global structure and more significant changes of the local heme microenvironment than upon adsorption onto smaller SNPs. The disruption of the heme microenvironment leads to a more solvent‐accessible protein active site, as suggested by Soret circular dichroism spectroscopy and through an increase in peroxidase activity as a function of increased SNP size. Similarly, the stability of cyt c decreases more dramatically upon adsorption onto larger SNPs. These results are consistent with changes in protein–nanoparticle interactions that depend on the size or surface curvature of the supporting nanostructure. This study provides further fundamental insights into the effects of nanoscale surfaces on adsorbed protein structure and function.
Rational Synthesis of Magnetic Thermosensitive Microcontainers as Targeting Drug Carriers
Authors: Chen Li‐Bo , Zhang Feng , Wang Chang‐Chun 
Published: February 2009

AbstractA new approach to the fabrication of magnetic thermosensitive microcontainers of Fe3O4 nanoparticles with poly(N‐isopropylacrylamide) walls is presented. The microcontainers undergo a temperature‐induced volume phase transition and present an impressive magnetic response. The microcontainers have a well‐defined structure with a narrow size distribution. The wall thicknesses of the microcontainers can be controlled according to requirements. Compared to other preparation methods, the process is simple and reproducible. The magnetic saturation of these microcontainers is high enough to meet most requirements of bioapplications. To further investigate the potential application of these microcontainers, they are tested as drug carriers, with the drug loading and releasing processes carefully studied. The drug encapsulation efficiency and drug content in the carriers are pH‐dependent, and the carriers have a maximal drug loading of about 50 wt% under alkaline conditions. The release of the drug from the microcontainers can be controlled by the environmental pH, temperature, and magnetic force.
Cobalt Nanoparticle Arrays made by Templated Solid‐State Dewetting
Authors: Oh Yong‐Jun , Ross Caroline A. , Jung Yeon Sik , Wang Yang , Thompson Carl V. 
Published: February 2009

AbstractSelf‐assembled cobalt particle arrays are formed by annealing, which cause agglomeration (dewetting) of thin Co films on oxidized silicon substrates that are topographically prepatterned with an array of 200‐nm‐period pits. The Co nanoparticle size and uniformity are related to the initial film thickness, annealing temperature, and template geometry. One particle per 200‐nm‐period pit is formed from a 15‐nm film annealed at 850 °C; on a smooth substrate, the same annealing process forms particles with an average interparticle distance of 200 nm. Laser annealing enables templated dewetting of 5‐nm‐thick films to give one particle per pit. Although the as‐deposited films exhibit a mixture of hexagonal close‐packed and face‐centered cubic (fcc) phases, the ordered cobalt particles are predominantly twinned fcc crystals with weak magnetic anisotropy. Templated dewetting is shown to provide a method for forming arrays of nanoparticles with well‐controlled sizes and positions.
A Simple Top‐Down/Bottom‐Up Approach to Sectored, Ordered Arrays of Nanoscopic Elements Using Block Copolymers
Authors: Park Soojin , Yavuzcetin Ozgur , Kim Bokyung , Tuominen Mark T. , Russell Thomas P. 
Published: February 2009

AbstractA top‐down/bottom‐up approach is demonstrated by combining electron‐beam (e‐beam) lithography and a solvent annealing process. Micellar arrays of polystyrene‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) with a high degree of lateral order can be produced on a surface where sectoring is defined by e‐beam patterning. The e‐beam is used to crosslink the block copolymer (BCP) film immediately after spin‐coating when the BCP is disordered or in a highly ordered solvent‐annealed film. Any patterns can be written into the BCP by crosslinking. Upon exposure to a preferential solvent for the minor component block followed by drying, cylindrical nanopores are generated within the nonexposed areas by a surface reconstruction process, while, in the exposed areas, the films remain unchanged. Nickel nanodot arrays can be placed over selected areas on a surface by thermal evaporation and lift‐off process.
A method for enterprise knowledge map construction based on social classification
Authors: Liu Lu , Li Jing , Lv Chenggong 
Published: February 2009

AbstractKnowledge map is an important and effective instrument for enterprise knowledge management. A large number of unordered knowledge resources in the enterprises bring about difficulties to the knowledge map construction. It is necessary to construct the enterprise knowledge map from a systematic perspective. Considering influences of individual's cognition on the organizational knowledge structure, this paper introduces social classification into the enterprise context and proposes a three‐level architecture for enterprise knowledge map construction, i.e. the individual knowledge tagging, the domain topic selection and the inter‐domain association analysis layer. In this architecture, domain serves as the basic unit to display knowledge and their relationships, as well as provides a pragmatic context for knowledge navigation and reuse. Incorporating the above elements, a method is formulated and applied to a real‐world case. Copyright © 2009 John Wiley & Sons, Ltd.
Analysing relational benefits in e‐business environment from behavioural perspective
Authors: Su Qin , Li Ling , Cui Yan Wu 
Published: February 2009

AbstractThis paper explores relational benefits from Chinese customer's behavioural perspective, which is a valuable addition to the existing literature that focuses on the western cultural background. The findings of this research show that the relational benefits exist in the online shopping context. In addition to confidence benefit, special treatment benefit and social benefit that have been recognized in traditional services, a new benefit scale, honour benefit, is identified in this study. Empirical data from over 500 online consumers suggest that the relational benefits are becoming more and more important and can possibly turn into the sources of the new competitive advantage for the enterprise in the e‐business environment. Copyright © 2009 John Wiley & Sons, Ltd.