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Temperature dependence of electron transport through a quantum shuttle

Anatoly Yu. Smirnov、Lev G. Mourokh2003-11-03arXiv

We analyze electron transport through a quantum shuttle for the applied voltage below the instability threshold. We obtain current-voltage characteristics of this system and show that at low temperature they exhibit pronounced steps. The temperature dependence of the current is calculated in the range from 2K to 300K…

Materials Science

Inverted current-driven switching in Fe(Cr)/Cr/Fe(Cr) nanopillars

M. AlHajDarwish、A. Fert、W. P. Pratt Jr 等 4 位作者2003-11-03arXiv

From both theory and experiment, scattering of minority electrons is expected to be weaker than scattering of majority electrons in both dilute Fe(Cr) alloys and at Fe(Cr)/Cr interfaces. We show that Fe(Cr)/Cr/Fe(Cr) trilayer nanopillars display a normal magnetoresistance--i.e., largest resistance at low magnetic fiel…

Materials Science

Local Order of Liquid and Supercooled Zirconium byAb InitioMolecular Dynamics

N. Jakse、A. Pasturel2003-11-03Physical Review Letters

It has been suggested that icosahedral short-range order (SRO) occurs in deeply undercooled melts of pure metallic elements. We report results of first-principles molecular dynamics simulations for stable and undercooled zirconium liquids. Our results emphasize the occurrence of a local order more complex than the ico…

High-pressure geophysics and materialsMaterial Dynamics and PropertiesTheoretical and Computational Physics

Mechanism and kinetics of the crosslinking reaction between biopolymers containing primary amine groups and genipin

Michael F. Butler、Yiu‐Fai Ng、Paul D. A. Pudney2003-11-03OpenAlex

Abstract The reaction mechanism of chitosan, bovine serum albumin (BSA), and gelatin with genipin (a natural crosslinking reagent) was examined with infrared, ultraviolet–visible, and 13 C NMR spectroscopies; protein‐transfer reaction mass spectrometry; photon correlation spectroscopy; and dynamic oscillatory rheometr…

Nanocomposite Films for Food PackagingPolymer Surface Interaction StudiesAdvanced Drug Delivery Systems

A Mutation in the Essential Gene gmk (Encoding Guanlyate Kinase) Generates a Requirement for Adenine at Low Temperature in Salmonella enterica

Brian J. Beck、M. K. Huelsmeyer、Scott M. Paul 等 4 位作者2003-11-02Journal of Bacteriology

In Salmonella enterica serovar Typhimurium, gmk encodes guanylate kinase, an essential enzyme involved in the synthesis and salvage of guanine nucleotides. Here we report the isolation of a mutation in gmk that results in a nutritional requirement for adenine at low temperature. Comparisons of kinetic parameters from…

Bacterial Genetics and BiotechnologyEndoplasmic Reticulum Stress and DiseaseEnzyme Structure and Function

Efficient electron spin detection with positively charged quantum dots

K. Gundogdu、K. C. Hall、Thomas F. Boggess 等 5 位作者2003-11-02arXiv

We report the application of time- and polarization-resolved photoluminescence up-conversion spectroscopy to the study of spin capture and energy relaxation in positively and negatively charged, as well as neutral, InAs self-assembled quantum dots. When compared to the neutral dots, we find that carrier capture and re…

Materials Science

On the origin of magnetoresistance in Sr$_2$FeMoO$_6$

D. D. Sarma、Sugata Ray、K. Tanaka 等 4 位作者2003-11-02arXiv

We report detailed magnetization ($M$) and magnetoresistance ($MR$) studies on a series of Sr$_2$FeMoO$_6$ samples with independent control on anti-site defect and grain boundary densities. These results, exhibiting a switching-like behavior of $MR$ with $M$, establish that the $MR$ is controlled by the magnetic polar…

Materials ScienceStrongly Correlated Electrons

Asymmetric Arrangement of Monolayer in the Multilayer Films of 2‐Hydroxy‐4,4'‐dihexyloxy‐azobenzene

Jian Jin、Gang Wang、Wensheng Yang 等 5 位作者2003-11-01Chinese Journal of Chemistry

Abstract Multilayer films of 2‐hydroxy‐4,4'‐dihexyloxy‐azobenzene (HAB) on silicon substrates have been studied with atomic force microscopy, temperature‐dependent FTIR, and X‐Ray diffraction technique. The results show that the multilayer films are formed by stacking of HAB monolayers via π‐π interactions and the adj…

Liquid Crystal Research AdvancementsMolecular Junctions and NanostructuresPhotochromic and Fluorescence Chemistry

Corrugation-type instability of the free motion of 180° domain walls in uniaxial ferromagnets

G. E. Khodenkov2003-11-01Technical Physics Letters

Investigation of the spectrum of oscillations of a 180° domain wall (DW) freely moving in a uniaxial ferromagnet shows that the one-dimensional structure becomes unstable with respect to surface distortions in the region of negative effective mass (negative differential mobility). The upper critical value of the pertu…

Magnetic properties of thin filmsMagnetic Properties of AlloysGeomagnetism and Paleomagnetism Studies

Modeling of texture evolution in copper under equal channel angular pressing

Seung Chul Baik、Yuri Estrin、Ralph Jörg Hellmig 等 6 位作者2003-11-01International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde)

Abstract Texture evolution was analyzed with the full-constraint Taylor model for an idealized perfectly plastic face-centered cubic material as well as for real, strain-hardening copper subjected to equal channel angular pressing (ECAP). For the idealized material, the stress in the plastically deformed part of the b…

Microstructure and mechanical propertiesMetal Forming Simulation TechniquesMetallurgy and Material Forming

A Study of Chemical and Physical Changes During Biaxially Oriented Polypropylene Film Production

Semra Ülkü、Devri̇m Balköse、Esen Arkış 等 4 位作者2003-11-01Journal of Polymer Engineering

Article A Study of Chemical and Physical Changes During Biaxially Oriented Polypropylene Film Production was published on November 1, 2003 in the journal Journal of Polymer Engineering (volume 23, issue 6).

Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesPolymer Science and PVC

Dielectric and thermoanalytical behavior and spectroscopic and kinetic evaluation of water in heat-resistant electrical insulating films

S. Yasufuku2003-11-01IEEE Electrical Insulation Magazine

Nowadays, along with requirements for developing heat-resistant electrical insulating materials, various kinds of high polymers with polar structures are used, which are characterized by high heat-stability, good electrical properties, hydrophilic nature, etc. While their heat-stability is beneficial to their uses, th…

Polymer Nanocomposites and PropertiesHigh voltage insulation and dielectric phenomenaEpoxy Resin Curing Processes

Physicochemical properties, surface morphology and particle size distribution of precipitated silicas

Jolanta Żurawska、Andrzej Krysztafkiewicz、Teofil Jesionowski2003-11-01Surface and Interface Analysis

Abstract The results presented are from a study on the production of highly dispersed silicas by their precipitation from solutions of sodium metasilicate and ammonium salts. The applied ammonium salts were NH 4 HCO 3 and (NH 4 ) 2 CO 3 . The precipitation process was conducted in the absence or presence of 1 wt.% non…

Polymer Nanocomposites and PropertiesPolymer Surface Interaction StudiesElectrophoretic Deposition in Materials Science

New aspects of porphyrin coordination chemistry in Russia and former Soviet Union countries

B. D. Berezin2003-11-01Journal of Porphyrins and Phthalocyanines

This paper summarizes what was discussed in a lecture at the IXth International Conference on Porphyrin Chemistry held in Suzdal (Russia) in September 2003. The development of porphyrin chemistry in former Soviet Union countries and over the world are discussed. Some ideas which were cultivated during three conditiona…

Porphyrin and Phthalocyanine ChemistryPhotodynamic Therapy Research StudiesPorphyrin Metabolism and Disorders

Effect of temperature on processes of radiation-induced generation of primary defects in MgF2 crystals

Л. А. Лисицына、V. I. Korepanov、T. V. Grechkina2003-11-01Optics and Spectroscopy

The spectral and kinetic parameters of the absorption and emission relaxation initiated by a single nanosecond-range electron pulse in MgF 2 crystals are studied in the temperature range 20–550 K. It is found that the relationship between the two channels of dissipation of the electronic excitation energy (generation…

Luminescence Properties of Advanced MaterialsGlass properties and applicationsSolid State Laser Technologies

Pressure assisted evolution of defects in silicon

C. A. Londos、M. S. Potsidi、J. Bąk‐Misiuk 等 5 位作者2003-11-01Crystal Research and Technology

Abstract The effect of enhanced hydrostatic pressure following heat treatment on the evolution of point defects in neutron‐irradiated Czochralski‐grown silicon is investigated using infrared spectroscopy. The behavior of oxygen‐related defects, particularly of the VO and the VO 2 centers, is mainly studied using sampl…

Semiconductor materials and devicesTransition Metal Oxide NanomaterialsElectron and X-Ray Spectroscopy Techniques

Specific electron transfer mechanism from the photoexcited tetrasulfonated Zn(II)‐tetraphenylporphyrin to methylviologen via self‐assembled ionic complex

Masao Kaneko、Kazuhisa Suzuki、Esther Ebel 等 4 位作者2003-11-01Macromolecular Symposia

Abstract Electron transfer from photoexcited tetrasulfonated Zn(II)‐tetraphenylporphyrin (ZnTSTPP) to methyviologen (MV 2+ ) was studied. From the investigation of relative fluorescence intensity and emission lifetime against the MV 2+ concentration, it was concluded that the electron transfer takes place by a static…

Porphyrin and Phthalocyanine ChemistryPhotochemistry and Electron Transfer StudiesElectrochemical Analysis and Applications

Calorimetric Approach and Simulation for Scale-Up of a Friedel−Crafts Reaction

Lucia Gigante、A. Lunghi、Simone Martinelli 等 8 位作者2003-11-01Organic Process Research & Development

The present study, on the optimisation of the scale-up of a Friedel−Crafts acylation, joins together experimental calorimetric techniques and simulation techniques. The adopted methodology involved the execution of isothermal tests at different temperatures, using the reaction calorimeter RC1, to obtain the heat flow…

Multicomponent Synthesis of HeterocyclesThermal and Kinetic AnalysisChemistry and Chemical Engineering

Molecular weight distribution in living polymerization proceeding with reshuffling of polymer segments due to chain transfer to polymer with chain scission. Part IV. Systems with cyclization

Ryszard Szymański、Jolanta Baran2003-11-01Polimery

Continuing a series of modeling studies of the influence of reshuffling of polymer segments on the polydispersity index (PDI), the additional effect of cyclization was analyzed by means of Monte Carlo simulations. It was shown that the contribution of cyclization in overall reshuffling process can be important only in…

biodegradable polymer synthesis and propertiesAdsorption, diffusion, and thermodynamic properties of materials

Effects of Growth Environment on Cotton Fiber Properties and Motes, Neps, and White Speck Frequency

Gayle H. Davidonis、Juan Landivar、C. Fernández2003-11-01Textile Research Journal

A number of preharvest and postharvest factors alter textile quality, including cotton variety, growth environment, harvest method, lint cleaning, and combing. In this work, the impact of three planting dates in 1997 and 1999 on fiber properties, mote, neps, and white specks is monitored. Cotton is hand picked, ginned…

Textile materials and evaluations