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A Response Regulatory Protein with the Site of Phosphorylation Blocked by an Arginine Interaction: Crystal Structure of Spo0F from Bacillus subtilis,

M. D. Madhusudan、James Zapf、James A. Hoch 等 6 位作者1997-10-01Biochemistry

Spo0F is a secondary messenger in the "two-component" system controlling the sporulation of Bacillus subtilis. Spo0F, like the chemotaxis protein CheY, is a single-domain protein homologous to the N-terminal activator domain of the response regulators. We recently reported the crystal structure of a phosphatase-resist…

Bacterial Genetics and BiotechnologyRNA and protein synthesis mechanismsEnzyme Structure and Function

Atomistically Modeling the Chemical Potential of Small Molecules in Dense Polymer Microstructures. 1. Method

Birgitta Knopp、Ulrich W. Suter、Andrei A. Gusev1997-10-01Macromolecules

A method is presented to estimate the excess chemical potential of solutes in dense polymer microstructures with a combination of the thermodynamic-integration approach and Widom's particle insertion from MD runs under constant NVT conditions on an atomistic level. The results obtained for pure water systems show good…

Polymer crystallization and propertiesMaterial Dynamics and PropertiesPolymer Nanocomposites and Properties

Effect of Random Packing on Stress Relaxation in Foam

Stephen A. Langer、Andrea J. Liu1997-10-01The Journal of Physical Chemistry B

Numerical simulations are conducted to examine the effect of randomness in the bubble packing on the local elastic properties of a foam. We find that the response to a small-amplitude strain is spatially inhomogeneous: there are regions (of several bubbles) where bubbles shift their positions in order to prevent disto…

Surface Modification and SuperhydrophobicityEnhanced Oil Recovery TechniquesPickering emulsions and particle stabilization

Thickness dependent low frequency relaxations in ferroelectric liquid crystals with different temperature dependence of the helix pitch

Vladimı́ra Novotná、Milada Glogarová、Alexej Bubnov 等 4 位作者1997-10-01Liquid Crystals

A low frequency relaxation mode 1 has been detected in ferroelectric phases of three materials. The relaxation frequency and the dielectric strength of this mode depend strongly on the sample thickness, but their temperature dependences are qualitatively different in the materials studied, reflecting the behaviour of…

Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesSurfactants and Colloidal Systems

Surface Defect Characterization in Oxygen-Dosed Nickel Surfaces and in NiO Thin Films by CO Adsorption−Desorption Experiments

H. Öfner、Francisco Zaera1997-10-01The Journal of Physical Chemistry B

Oxygen-covered Ni(110) as well as thin NiO films grown by oxidation of that surface were characterized under ultrahigh vacuum by using low-energy electron diffraction (LEED), X-ray photoelectron (XPS), Auger (AES), and ion scattering (ISS) spectroscopies together with CO temperature-programmed desorption (TPD) titrati…

ZnO doping and propertiesCatalytic Processes in Materials ScienceSemiconductor materials and devices

Suggested Correlation between the Visible Photoluminescence and the Fourier Transform Infrared Spectrum of a Porous Silicon Surface

James L. Gole、David A. Dixon1997-10-01The Journal of Physical Chemistry B

The FTIR spectrum for a heavily oxidized porous silicon (PS) surface is considered. It is suggested that a portion of this spectrum be reassigned to the Si O stretch frequency of a surface bound-silanone-based silicon oxyhydride consistent also with the 18 O 2 / 16 O 2 isotopic labeling of the FTIR spectrum and with m…

Semiconductor materials and devicesSilicon Nanostructures and PhotoluminescenceNanowire Synthesis and Applications

Photoregulated Liquid Crystal Alignment on Photoreactive Side-Chain Liquid-Crystalline Polymer

Nobuhiro Kawatsuki、Hirohumi Takatsuka、Tohei Yamamoto Ono1997-10-01Japanese Journal of Applied Physics

We describe the anisotropic photoreaction of photoreactive side-chain liquid-crystalline polymers (SLCPs), containing biphenyl mesogen and photoreactive cinnamoyl group, by irradiation with a linearly polarized (LP) UV light, and the alignment behavior of the low-molecular-weight (LMW) liquid crystal (LC) on them. The…

Liquid Crystal Research AdvancementsSynthesis and Properties of Aromatic CompoundsPlant Reproductive Biology

Long-time translational self-diffusion in isotropic dispersions of colloidal rods

M. P. B. van Bruggen、H. N. W. Lekkerkerker、Jan K. G. Dhont1997-10-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics

A dispersion of fluorescent colloidal silica coated boehmite rods with length $L\ensuremath{\approx}325\mathrm{nm}$ and diameter $D\ensuremath{\approx}46\mathrm{nm},$ dispersed in dimethylformamide, is synthesized. The concentration dependence of the long-time translational self-diffusion coefficient ${D}_{s}^{L}$ is…

Material Dynamics and PropertiesSurfactants and Colloidal SystemsAdsorption, diffusion, and thermodynamic properties of materials

Plasma‐assisted CVD of cubic boron nitride

I. Konyashin、Joachim Bill、Fritz Aldinger1997-10-01Chemical Vapor Deposition

Abstract Single‐phase cubic boron nitride films of high quality might be of great importance as superhard wear‐resistant coatings and semiconductive materials. This paper reviews deposition techniques, precursors, deposition parameters and substrates employed in plasma‐assisted CHEMICAL VAPOR DEPOSITION (PACVD) of cub…

Metal and Thin Film MechanicsDiamond and Carbon-based Materials ResearchBoron and Carbon Nanomaterials Research

A new method for measuring thermal conductivity of thin films

S. A. Govorkov、W. Ruderman、Mark W. Horn 等 5 位作者1997-10-01Review of Scientific Instruments

A new, relatively inexpensive, easy-to-use instrument has been developed for measuring the thermal conductivity of thin films based on a differential photoacoustic method. Measurements made on silicon dioxide and silicon nitride are consistent with those reported previously for a different technique. In addition, the…

Ultrasonics and Acoustic Wave PropagationThermal properties of materialsThermography and Photoacoustic Techniques

Structure and Thermodynamics of Homogeneous-Dendritic-Polymer Solutions: Computer Simulation, Integral-Equation, and Lattice-Cluster Theory

Leo Lue、John M. Prausnitz1997-10-01Macromolecules

We present some calculated structural and thermodynamic properties of homogeneous-dendritic-polymer solutions using computer simulation methods, integral-equation theory, and lattice-cluster theory. Monte-Carlo methods are used to sample conformations of polymer molecules. From these conformations, we first compute tw…

Advanced Polymer Synthesis and CharacterizationLubricants and Their AdditivesDendrimers and Hyperbranched Polymers

In Search for Mononuclear Helical Lanthanide Building Blocks with Predetermined Properties: Lanthanide Complexes with Diethyl Pyridine‐2, 6‐Dicarboxylate

Fabien Renaud、Claude Piguet、Gérald Bernardinelli 等 5 位作者1997-10-01Chemistry - A European Journal

Abstract The ligand diethyl pyridine‐2, 6‐dicarboxylate ( L 5 ) reacts with Ln III in acetonitrile to successively give the complexes [Ln( L 5 ) i ] 3 + (Ln = La to Lu, i = 1‐3). Spectroscopic investigations (ES‐MS, UV/Vis, NMR) show that the 1:3 complexes [Ln( L 5 ) 3 ] 3 + have poor stability in solution and exist a…

Magnetism in coordination complexesRadioactive element chemistry and processingLanthanide and Transition Metal Complexes

Temperature-dependent valence-band photoemission spectra ofLa1−xSrxMnO3

T. Saitoh、A. Sekiyama、K. Kobayashi 等 8 位作者1997-10-01Physical review. B, Condensed matter

We have studied the temperature dependence of the photoemission spectra of La${}_{1\ensuremath{-}x}$Sr${}_{x}$MnO${}_{3}$ $(x$=0.0, 0.2, and 0.4) and found that the spectral line shape dramatically changes in the entire valence-band region, particularly for $x$=0.2 and 0.4. By contrast, the spectra of La${}_{0.6}$Sr${…

Magnetic and transport properties of perovskites and related materialsAdvanced Condensed Matter PhysicsElectronic and Structural Properties of Oxides

Structure and growth mechanism of tetrapod-like ZnO particles

Koji Nishio、Toshiyuki Isshiki、Motoi Kitano 等 4 位作者1997-10-01Philosophical magazine. A/Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties

Tetrapod-like ZnO particles having four legs shorter than a micrometre have been observed by transmission electron microscopy and electron diffractometry. The particles are composed of six or more wurtzite-type elements. Four of them make legs and others form (1122) twins with the legs. Particles composed of only four…

ZnO doping and properties

Vibrationally Resolved Photoelectron Spectra of TiCx- (x = 2−5) Clusters

Xuebin Wang、Chuan‐Fan Ding、Lai‐Sheng Wang1997-10-01The Journal of Physical Chemistry A

Vibrationally resolved photoelectron spectra are obtained for the small TiC x - ( x = 2−5) clusters. Adiabatic electron affinities (EAs) and low-lying electronic states are measured for the neutral TiC x clusters. While the EAs are similar for the series of clusters, 1.542 eV for TiC 2, 1.561 eV for TiC 3, 1.494 eV fo…

Graphene research and applicationsMetal and Thin Film MechanicsBoron and Carbon Nanomaterials Research

Imine-Bridged Planar Poly(phenylenethiophene)s and Polythiophenes

Qing T. Zhang、James M. Tour1997-10-01Journal of the American Chemical Society

Synthetic routes to soluble planar poly(phenylenethiophene)s and polythiophenes are described. The main polymer backbones are synthesized via Pd(0)-catalyzed couplings of the electron-rich N,N ‘-(bis- tert -butoxycarbonyl)-3,4-diamino-2,5-bis(tri- n -butylstannyl)thiophene with electron-deficient aryldibromodiones. Th…

Organic Electronics and PhotovoltaicsConducting polymers and applicationsPorphyrin and Phthalocyanine Chemistry

Influence of Pseudohalide Ions on the Molecular Structure and Magnetic Properties of the Manganese(II)−Bipyrimidine−Pseudohalide System

Roberto Cortés、M. Karmele Urtiaga、Luís Lezama 等 6 位作者1997-10-01Inorganic Chemistry

The compounds [Mn 2 (bpm) 3 (NCS) 4 ] ( 1 ), [Mn(bpm)(NCO) 2 ] ( 2 ), and [Mn 2 (bpm)(N 3 ) 4 ] ( 3 ) (where bpm= 2,2‘-bipyrimidine) have been synthesized and characterized. Compound 1 crystallizes in the triclinic P 1̄ space group, with a = 9.122(1) Å, b = 9.229(1) Å, c = 11.710(2) Å, α = 74.89(1)°, β = 80.30(1)°, γ…

Metal-Organic Frameworks: Synthesis and ApplicationsMetal complexes synthesis and propertiesMagnetism in coordination complexes

Direct measurements of the stopping power for antiprotons of light and heavy targets

S. Möller、E. Uggerhøj、H. Bluhme 等 7 位作者1997-10-01Physical Review A

Measurements of antiproton stopping powers around the stopping-power maximum are presented for targets of Al, Si, Ti, Cu, Ag, Ta, Pt, and Au. The Low Energy Antiproton Ring antiproton beam of 5.9 MeV is degraded to 50--700 keV, and the energy loss is found by measuring the antiproton velocity before and after the targ…

Atomic and Molecular PhysicsX-ray Spectroscopy and Fluorescence AnalysisElectron and X-Ray Spectroscopy Techniques

Structural Study of an Al72Ni20Co8Decagonal Quasicrystal Using the High-Angle Annular Dark-Field Method

Koh Saitoh Pang Tsai1997-10-01Japanese Journal of Applied Physics

High-angle annular dark-field (HAADF) images of an Al 72 Ni 20 Co 8 decagonal quasicrystal have been taken for the first time. It has been found that the transition metals form pentagonal and star-shaped cluster columns with radii of about 0.4 nm. The atom-cluster columns with a 2 nm diameter of the alloy, which have…

Quasicrystal Structures and PropertiesX-ray Diffraction in CrystallographyMineralogy and Gemology Studies

Computer simulation studies of confined liquid-crystal films

Greg D. Wall、Douglas J. Cleaver1997-10-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics

In this paper we present results from molecular dynamics simulations performed using a system of Gay-Berne particles confined between two substrates in a slab geometry. We use a nonseparable anisotropic molecule-substrate interaction potential and investigate weak and moderate molecule-substrate coupling strengths. We…

Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesSurfactants and Colloidal Systems