bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mayonnaise, Aioli & Co
Authors: Vilgis Thomas 
Published: August 2004

AbstractHätten Sie einmal Lust auf selbst gemachte Mayonnaise? Oder ein cremiges, nach Knoblauch duftendes Aioli? Mögen Sie Fisch und eine kräftige Remoulade? Kein Problem, vor allem für Physiker, denn sie wissen, was zu tun ist, schließlich gehorchen all diese Kulinarien bestimmten molekularen Prinzipien.
Poly(vinyl acetate‐co‐dibutyl maleate) latex films in the presence of grafted and post‐added poly(vinyl alcohol)
Authors: Wu Jun , Li Huxi , Winnik Mitchell A. , Farwaha Rajeev , Rademacher Jude 
Published: August 2004

AbstractWe describe the synthesis and characterization of a series of poly(vinyl acetate‐co‐dibutyl maleate) [P(VAc‐DBM)] latex particles (monomer molar ratio 10.6:1). One set of samples [high‐MandM250kSDS‐P(VAc‐DBM), gel content 50% and 0%] was prepared in the presence of an anionic surfactant sodium dodecyl sulfate. The other two sets of samples [high‐MandM250kPVOH–P(VAc‐DBM)] were prepared in the presence of poly(vinyl alcohol) (PVOH). These polymers differ in gel content (50 and 0%) and the extent of PVOH grafting (30 and 15%). Polymer diffusion across cell boundaries in the latex films was monitored by fluorescence resonant energy transfer (ET) experiments. First, we examinedM250ksamples in the presence of grafted and post‐added PVOH. The presence of post‐added PVOH (5%) causes a small but detectable retardation on the rate of polymer diffusion, whereas the presence of grafted PVOH (degree of grafting: 15%) significantly promotes the polymer diffusion rate. For the high‐MP(VAc‐DBM), the presence of post‐added PVOH also retards the polymer diffusion. Strikingly, the presence of grafted PVOH (degree of grafting: 30%) in the high‐MPVOH‐P(VAc‐DBM) promotes the polymer diffusion to such an extent that the diffusion was complete in the freshly prepared films. Our data also suggest that under our experimental conditions, the rate of P(VAc‐DBM) diffusion increases with an increase of the degree of PVOH grafting. To confirm these results, we carried out fluorescence microscopy experiments to monitor the fate of PVOH in these latex films and found that in newly formed PVOH–P(VAc‐DBM) films, the PVOH was either uniformly distributed in the P(VAc‐DBM) matrix or the domains were too small to be resolved (i.e., < 0.5 μm). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5005–5020, 2004
Synthesis and characterization of alkylated N‐vinylformamide monomers and their polymers
Authors: Shi Lianjun , Boduch‐Lee Keri A. , Henssler John T. , Beckman Eric J. , Chapman Toby M. 
Published: August 2004

AbstractN‐alkyl‐N‐vinylformamide monomers (alkyl: n‐butyl, hexyl, decyl, and dodecyl) are synthesized in two steps: first, preparation of N‐vinylformamide potassium salt by the reaction of N‐vinylformamide (NVF) with potassium t‐butoxide, then reaction with alkyl bromide. All four monomers are liquid and are characterized by IR, 1H NMR, 13C NMR, and mass spectra. They exist as rotomers in solution and a 2D NOE experiment on the N‐hexyl containing polymer shows the E isomer to be favored. The polymerizability of the four monomers is from good to fair, depending upon the length of alkyl chain on the N‐atom‐‐the longer the chain length, the lower lower the polymerizability of monomer. The hydrolysis of poly(N‐hexyl‐N‐vinylformamide) and poly(N‐dodecyl‐N‐vinylformamide) under acidic and basic conditions was examined. Studies show that hydrolytic cleavage of formyl groups of poly (N‐alkylated‐N‐vinylformamide) depends on the hydrophobicity of the alkyl substituent on the N‐atom under acidic conditions; both polymers were hydrolyzed to only a minor extent under alkaline conditions. The N‐alkylated monomers can copolymerize with NVF and demonstrate amphiphilic properties. The copolymers demonstrate a critical aggregation concentration above which they can solubilize a water insoluble dye; the N‐hexyl containing copolymer stabilizes a castor oil‐in‐water emulsion. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4994–5004, 2004
D. P. Chatterjee, U. Chatterjee, and B. M. Mandal, "Atom transfer radical polymerization of methyl methacrylate at ambient temperature using soluble Cu(I) complex catalysts formed with mixed ligands of multidentate amines and halide ions," J Polym Sci Part A: Polym Chem (2004) 42(17) 4132–4142
Authors: Chatterjee Dhruba P. , Chatterjee Uma , Mandal Broja M. 
Published: August 2004

AbstractThe original article to which this Erratum refers was published in J Polym Sci Part A: Polym Chem (2004) 42(17) 4132–4142No abstract.
Gallium nitride nanowires with a metal initiated metal‐organic chemical vapor deposition (MOCVD) approach
Authors: Lee Sang‐Kwon , Choi Heon‐Jin , Pauzauskie Peter , Yang Peidong , Cho Nam‐Kyu , Park Hyo‐Derk , Suh Eun‐Kyung , Lim Kee‐Young , Lee Hyung‐Jae 
Published: August 2004

AbstractWe have studied structural and electrical properties of one dimensionally grown single crystalline gallium nitride (GaN) nanowires (NWs) for nanoscale devices using a metal‐initiated metal‐organic chemical vapor deposition (MOCVD). GaN nanowires were formed via the vapor‐liquid‐solid (VLS) mechanism with gold, iron, or nickel as growth initiators and were found to have triangular cross‐sections with widths of 15 ∼ 200 nm and lengths of 5 ∼ 20 μm. TEM confirmed that the nanowires were single crystalline and were well oriented along the [210] or [110] direction on substrate depending on the metal initiators. For electrical transport properties of un‐doped GaN nanowires, the back‐gated field effect transistors (FET) were also fabricated by standard e‐beam lithography. In our electrical measurement, the carrier concentration and mobility were ≈2 ∼ 4 × 1018 cm–3 and 60 ∼ 70 cm2/V s, respectively. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of magnetic clusters in Co‐doped ZnO using neutron scattering
Authors: Lee Hyeon‐Jun , Ryu Gi‐Hun , Kim Sung‐Kyu , Kim Shin Ae , Lee Chang‐Hee , Jeong Se‐Young , Cho Chae Ryong 
Published: August 2004

AbstractWe report on a study of magnetic cluster in Co‐doped ZnO using neutron diffraction. The samples are fabricated by the sol–gel process and the structural properties are characterized by X‐ray diffraction and neutron diffraction. The diffraction data obtained by neutron are compared with the results of X‐ray diffraction and refined by the Rietveld refinement method. The secondary phases are detected by neutron diffraction in above 5 mol% Co‐doping of ZnO samples and the fractions of the phases in the samples are calculated. In particular, the Co metal phase is clearly observed in 30 mol% Co‐doped ZnO. However, these secondary phases are not detected by X‐ray diffraction due to reasons such as X‐ray absorption by CoK‐edge and incoherent X‐ray scattering. We discuss the advantage of using neutron diffraction in studying the secondary phase and suggest the solubility limit of Co‐doping. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence and Raman scattering in Mg and P co‐implanted GaN epitaxial layers
Authors: Liu K. T. , Su Y. K. , Chang S. J. , Onomitsu K. , Horikoshi Y. 
Published: August 2004

AbstractOptical properties of P–Mg co‐implanted GaN epitaxial layers with P/Mg concentration ratios of 0–0.5 have been studied. It is found that the photoluminescence intensity significantly increases with the P/Mg ratio, probably due to the suppression of N vacancy generation by co‐implanted P atoms. New photoluminescence lines caused by P‐related transitions are observed for samples with a large P/Mg ratio. Unlike the usual donor‐acceptor pair emission peaks, these newly observed peaks exhibit clear red shifts when the temperature is increased. The P‐related emission is found to be associated with the recombination of electrons on the shallow native donors with holes on isoelectronic P traps. The photoluminescence study suggests that the isoelectronic P trap forms a stable charged state in the P–Mg co‐implanted GaN with a hole binding energy of approximately 220 meV. In addition, Raman measurements indicate that the P–Mg co‐implanted GaN layers are to be annealed at 1200 °C for 10s to achieve a sufficient recovery of crystal quality. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photo‐induced absorption change for InGaN film by violet laser diode
Authors: Nomura Masahiro , Arita Munetaka , Ashihara Satoshi , Nishioka Masao , Arakawa Yasuhiko , Shimura Tsutomu , Kuroda Kazuo 
Published: August 2004

AbstractWe have investigated photo‐induced absorption changes for In0.10Ga0.90N multiple quantum wells and a thin film induced by a continuous‐wave (cw) beam and a femtosecond pulse in the violet region. For the thin‐film sample, nearly the same absorption changes were observed in cw pumping and pulse pumping measurements. Screening of the piezoelectric field in InGaN heterostructures causes absorption changes around the band edge. This screening results from spatial separation of electron–hole pairs to the opposite sides of the InGaN epilayer. These spatially separated carriers are trapped in deep levels and maintain the absorption changes. The trapped charges are considered to be thermally excited to the conduction band and diffuse to attain the equilibrium state. This process takes on the order of 100 μs and such a long decay time of absorption changes allows us to have large absorption changes even by low‐intensity cw pumping. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eu concentration dependence on structural and optical properties of Eu‐doped GaN
Authors: Bang Hyungjin , Morishima Shinichi , Tsukamoto Takaharu , Li Zhiqiang , Sawahata Junji , Seo Jongwon , Takiguchi Mikio , Bando Yoshio , Akimoto Katsuhiro 
Published: August 2004

AbstractThe structural and optical properties of europium‐doped GaN were studied. The Eu‐related luminescence was observed at 622 nm and originated from the intra‐4f transition of the Eu3+ ion. The intensity of the luminescence increased as the Eu concentration increased up to about 3 at%, and then abruptly decreased. In‐situ reflection high‐energy electron diffraction (RHEED) and X‐ray diffraction (XRD) were carried out to study this luminescence quenching, and it was discovered that there is a close relationship between the luminescence intensity at 622 nm and the structural properties. The cause of the concentration quenching is likely related to the polycrystalline growth as well as to the formation of EuN. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Epitaxial growth of hexagonal and cubic InN films
Authors: Nishida K. , Kitamura Y. , Hijikata Y. , Yaguchi H. , Yoshida S. 
Published: August 2004

AbstractWe have grown InN films on 3C‐SiC (001) substrates with and without cubic GaN underlayers by RF‐N2 plasma MBE. It was found that, in the case of direct growth on 3C‐SiC (001), hexagonal InN grows with the crystal orientation as hexagonal InN (1 $ \bar 1 $00)//3C‐SiC (110), while, in the case of the growth on cubic GaN underlayers, cubic InN grows with the crystal orientation as cubic InN (110)//cubic GaN (110). Photoluminescence emissions from the cubic and hexagonal InN films were clearly observed at around 0.7 eV. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effects of strained sapphire (0001) substrate on the structural quality of GaN epilayer
Authors: Cho Yong Suk , Kim Jeakyun , Park Young Ju , Na Hyunseok , Kim Hee Jin , Kim Hyun Jin , Yoon Euijoon , Kim Young Woon 
Published: August 2004

AbstractWe investigated the structural properties of GaN epilayers grown on strained sapphire (0001) substrate by metal‐organic chemical vapor deposition (MOCVD). To minimize the mismatch in lattice constants and thermal expansion coefficients between the sapphire substrate and the GaN epilayer, we imposed the strain onto the sapphire (0001) substrate using high‐energy O+, Cl+, and As+ ion implantation. The strained sapphire surfaces result in the different behaviors of defect generation in the GaN epilayer. Not only the ionic species but also the thickness of the low‐temperature GaN buffer layer on sapphire affected the structural quality of the GaN epilayer. The present results show that O+ ion‐implanted substrate can provide an improved GaN epilayer using only a thin (∼5 nm) buffer layer rather than using a thicker one. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐principle study on electronic properties of gallium nitride and aluminium nitride nanowires
Authors: Doi Kentaro , Higashimaki Nobuyuki , Kawakami Yoshihiko , Nakamura Koichi , Tachibana Akitomo 
Published: August 2004

AbstractIn this work, one‐dimensional wire structures of gallium nitride (GaN) and aluminium nitride (AlN) are studied by first‐principle methods. These wire structures have interesting properties different from those of the bulks. We devised two types of wire structures named axial joint model and equatorial joint model. These initial structures are optimized and energy band structures of these optimized structures are calculated. The energy band gaps of GaN nanowires are 0.26 eV in the axial bond model and 0.08 eV in the equatorial one and those of AlN nanowires are 2.68 eV in the axial model and 0.16 eV in the equatorial one. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polarity control of ZnO films grown with high temperature N‐polar GaN intermediate layers by plasma‐assisted molecular beam epitaxy
Authors: Roh O. H. , Tomita Y. , Ohsugi M. , Wang X. , Ishitani Y. , Yoshikawa A. 
Published: August 2004

AbstractZnO epilayers were grown on nitridated c‐Al2O3 substrates by plasma‐assisted molecular beam epitaxy and the effect of the deposition temperature for GaN buffer and/or intermediate layers on the polarity of ZnO epilayer was investigated. First, it was found that the polarity of the ZnO epilayers grown on low temperature‐grown GaN buffer and/or intermediate layers was uncertain and it became often +c polarity, i.e., Zn‐polarity. This seems strange because the polarity of the GaN‐underlying layer was –c polarity, i.e., N‐polarity, and then the polarity of the under layer was not kept unchanged by the following epilayer. On the other hand, when the growth temperature of the GaN buffer/intermediate layer was increased above 850 °C, it was found that the polarity of the GaN layer was followed by the ZnO epilayers; the polarity became –c polarity, i.e., O‐polarity. This reason was estimated by the effect of surface oxides on GaN which were formed just before the deposition of ZnO buffer layer on it. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Direct heteroepitaxial lateral overgrowth of GaN on stripe‐patterned sapphire substrates with very thin SiO2 masks
Authors: Cheong H. S. , Yoo M. K. , Kim H. G. , Bae S. J. , Kim C. S. , Hong C.‐H. , Baek J. H. , Kim H. J. , Yu Y. M. , Cho H. K. 
Published: August 2004

AbstractDirect heteroeptaxial lateral overgrowth of GaN was performed on sapphire substrates by low‐pressure metalorganic chemical vapor deposition. The substrates were patterned with very thin SiO2 stripes with the thickness of 200∼300 Å. The growth was carried out by a two‐step condition. In the first step for facet‐controlled epitaxy, the formation of a triangular cross‐section of GaN stripes grown directly on the patterned sapphire was achieved to terminate threading dislocations (TDs) in the opening regions on the inclined {11–22} facets. During the second step for lateral growth, the TDs were bended completely by strong lateral overgrowth. The densities of the step terminations in atomic force microscopic images, corresponding screw‐ or mixed‐type TDs were effectively reduced to less than 107 cm–2 over the entire region. The crystallographic tilt between the mask and the opening regions was also well suppressed by using the very thin SiO2 mask as thick as GaN nucleation layer. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Applicability criterion for semiclassical Bohmian dynamics
Authors: Garashchuk Sophya , Rassolov Vitaly A. 
Published: August 2004

AbstractIn this paper we develop a criterion of the applicability for the trajectory‐based semiclassical propagation methods that are exact for Gaussian wavepackets in locally quadratic potentials. The error estimate takes into account a deviation of the wavefunction from the Gaussian form due to the anharmonicity of a potential. The derivation is based on the time‐dependent noncoherent solutions of the Schrödinger equation for a general quadratic potential that form a complete orthonormal time‐dependent basis. The anharmonicity is treated as a time‐dependent cubic perturbation, which is further related to the nonlinearity of a force acting on trajectories. The criterion is expressed in terms of scalar products of the average force, its first moments, and dispersion of the wavefunction and is efficient in the context of dynamics with the Bohmian trajectories. We give an application for the Bohmian dynamics with the approximate quantum potential, for the Gaussian wavepacket dynamics and for the semiclassical initial value representation propagator. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Ensemble‐averaged variational transition state theory with optimized multidimensional tunneling for enzyme kinetics and other condensed‐phase reactions
Authors: Truhlar Donald G. , Gao Jiali , Garcia‐Viloca Mireia , Alhambra Cristobal , Corchado Jose , Luz Sanchez Maria , Poulsen Tina D. 
Published: August 2004

AbstractThis paper provides an overview of a new method developed to include quantum mechanical effects and free energy sampling in calculations of reaction rates in enzymes. The paper includes an overview of variational transition state theory with optimized multidimensional tunneling for simple gas‐phase reactions and then shows how this is extended to incorporate free energy effects and to include protein motions in the reaction coordinate by ensemble averaging. Finally we summarize recent comparisons to experiment for primary and secondary kinetic isotope effects for proton and hydride transfer reactions catalyzed by enzymes. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Theoretical study of stabling function of the NO to the (CH3)3CO · radical
Authors: Zhao Hongmei , Liu Kun , Ma Siyu , Li Zonghe 
Published: August 2004

AbstractThe stabling function of the NO to the (CH3)3CO · radical has been theoretically investigated. Density functional theory (DFT) calculations are performed to optimize the geometries of relevant species. The single‐point energy is evaluated at CCSD(T)/6‐31++G** level. Three reaction channels of (CH3)3CO · + NO in the singlet state are considered. The calculations indicate that NO is a stable reagent of active radical (CH3)3CO. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Neural membrane field effects in a cytoskeleton corral: Microdomain regulation of impulse propagation
Authors: Wallace Ron 
Published: August 2004

AbstractThis article proposes that electrostatic interaction between transiently polarized neural‐membrane ethenes and charged residues of an unfolded ion‐channel protein regulate channel closing and electrical signaling in neurons. Field effects are confined by a cytoskeleton corral that gates movement of membrane lipids from one corralled region to another. Cytoskeleton gating permits stepwise changes in the concentration of unsaturated lipids and thereby modulates ion‐channel activity. The system is hypothesized to operate at axonal branch points where impulse conduction has a low safety factor. Throughout the discussion the A‐current delayed‐rectifier potassium channel is used as an example. Implications of the model for molecular networks are briefly discussed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Application of transfer Hamiltonian quantum mechanics to multi‐scale modeling
Authors: Mallik Aditi , Taylor DeCarlos E. , Runge Keith , Dufty James W. 
Published: August 2004

AbstractIn quantum mechanical/classical mechanical (QM/CM) partitioning methods for multi‐scale modeling, one is often forced to introduce uncontrolled phenomenological effects of the environment (CM) in the quantum (QM) domain, as ab initio quantum calculations are computationally too intensive to be applied to the whole sample. We propose a method in which two qualitatively different components of the information about the state of the CM region are incorporated into the QM calculations. First, pseudoatoms constructed to describe the chemistry of the nearest‐neighbor exchange interactions replace the atoms at the boundary of the CM and the QM regions. Second, the remaining effect of the CM bulk environment due to long‐range Coulombic interactions is modeled in terms of dipoles. We have tested this partitioning method in a silica nanorod and a three‐membered silica ring for which ab initio quantum data for the whole system are available to assess the quality of the proposed partitioning method. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Fast preparation method of effective pure states for NMR‐quantum computer with controlled‐not gates
Authors: Kawamura Minaru , Sawae Ryuichi , Kumaya Takashi , Takarabe Kenichi , Manmoto Yoshinori , Sakata Toshio 
Published: August 2004

AbstractA fast method to prepare effective pure states for NMR‐quantum computer in homo‐nuclear spin system is proposed. The temporal averaging method has been introduced to prepare an effective pure state in NMR‐quantum computer, but the method requires many experiments, whose number increases exponentially with the number of quantum bits (qubits), and it seems that a huge number of logical gates are required. The proposed method avoids this problem by eliminating a part of elements in the density matrices. This method requires only one ancillary qubit and two different experiments; the steps have been confirmed to be proportional to the number of qubits up to four‐qubit. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Determination of the absolute configuration of calliactine by quantum chemical calculations
Authors: Voloshina Elena , Raabe Gerhard , Estermeier Michael , Steffan Bert , Fleischhauer Jörg 
Published: August 2004

AbstractThe chiroptical properties of calliactine (2) have been studied experimentally as well as by quantum chemical calculations based on density functional theory (DFT). According to the DFT calculations, the four energetically lowest conformers of the title compound lie within a range of 1.1 kcal/mol and are separated from other conformers by an energy gap of nearly 9 kcal/mol. Based on their geometries, the excitation energies and rotational strengths have been calculated using time‐dependent DFT (TDDFT) and the dipole velocity formalism. The circular dichroism (CD) spectrum of calliactine has been obtained as a Boltzmann‐weighted superposition of the spectra of each of the four structures. By comparison of the calculated and experimental CD spectra, the absolute configuration of calliactine has been elucidated as S. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004