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第 184651 / 190634 页 · 当前展示 3,693,001–3,693,020 / 3,812,669 条匹配结果 · 摘要仅作预览

High-resolution structures of scytalone dehydratase-inhibitor complexes crystallized at physiological pH

Z. Wawrzak、Tatyana Sandalova、James J. Steffens 等 7 位作者1999-06-01Proteins Structure Function and Bioinformatics

Scytalone dehydratase is a molecular target of inhibitor design efforts aimed at preventing the fungal disease caused by Magnaporthe grisea. A method for cocrystallization of enzyme with inhibitors at neutral pH has produced several crystal structures of enzyme-inhibitor complexes at resolutions ranging from 1.5 to 2.…

Carbohydrate Chemistry and SynthesisEnzyme Structure and FunctionBiochemical and Molecular Research

Electronic Spectra of the Electrogenerated 1,4-Benzoquinone π-Dianion and the Strongly Hydrogen-Bonded Charge-Transfer Complex with Methanol

Noriko Okumura、Bunji Uno1999-06-01Bulletin of the Chemical Society of Japan

Abstract Electronic spectra of the active π-electronic dianion of 1,4-benzoquinone and its hydrogen-bonded complex with CH3OH, generated at sequential electroreduction steps, have been discussed from the points of view of the observation techniques and n–σ charge-transfer interaction of the dianion with a weak hydroge…

Porphyrin and Phthalocyanine ChemistryPhotochromic and Fluorescence ChemistryOrganic Chemistry Cycloaddition Reactions

Fully relativistic spin-polarized LMTO calculations of the magneto-optical Kerr effect ofdandfferromagnetic materials. I. Chromium spinel chalcogenides

V. N. Antonov、Vladimir Antropov、B. N. Harmon 等 5 位作者1999-06-01Physical review. B, Condensed matter

${\mathrm{CuCr}}_{2}{\mathrm{Se}}_{4}$ is one of the few compounds that exhibits a magneto-optical (MO) Kerr angle of greater than one degree at room temperature. To better understand the origin of this effect, the MO properties of ferromagnetic ${\mathrm{CuCr}}_{2}{X}_{4} (X=\mathrm{S},\mathrm{}\mathrm{S}\mathrm{e},\…

Magnetic and transport properties of perovskites and related materialsIron-based superconductors researchHeusler alloys: electronic and magnetic properties

Effects of annealing conditions on charge loss mechanisms in MOCVD Ba0·7Sr0·3TiO3 thin film capacitors

J. D. Baniecki、R. B. Laibowitz、T. M. Shaw 等 10 位作者1999-06-01Journal of the European Ceramic Society

The leakage and dielectric relaxation currents of MOCVD Ba0·7Sr0·3TiO3 thin films with Pt electrodes after post top electrode anneals in oxygen and forming gas (95% Ar, 5% H2) were investigated. The Schottky barrier height for thermionic emission of electrons from the cathode varied depending on annealing conditions.…

Ferroelectric and Piezoelectric MaterialsSemiconductor materials and devicesSemiconductor materials and interfaces

Relationship of fracture behavior and morphology in polyolefin blends

Ute Niebergall、Jürgen Bohse、Britta L. Schürmann 等 5 位作者1999-06-01Polymer Engineering and Science

Abstract High‐density polyethylene (HDPE) and isotactic polypropylene (PP) were mixed either with a stabilizer or with a stabilizer and a compatibilizer in different mixing ratios. The structure and properties of these blends were analyzed by methods such as torsion pendulum measurements, mechanical short time experim…

Mechanical Behavior of CompositesPolymer crystallization and propertiesFiber-reinforced polymer composites

Characteristics of slow and fast ion dynamics in a lithium metasilicate glass

Junko Habasaki、Yasuaki Hiwatari1999-06-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics

Molecular dynamics simulations of lithium metasilicate (Li(2)SiO(3)) glass have been performed. The motion of lithium ions is divided into slow (A) and fast (B) categories in the glassy state. The waiting time distribution of the jump motion of each component shows power law behavior with different exponents. Slow dyn…

Material Dynamics and PropertiesGlass properties and applicationsTheoretical and Computational Physics

Transmembrane pH gradients in vivo: measurements using fluorinated vitamin B6 derivatives.

Ralph P. Mason1999-06-01PubMed

It is well recognized that pH plays a significant regulatory role in most cellular processes. Increasingly, there is interest in transmembrane pH gradients, particularly with respect to tumor growth and response to therapy. NMR offers a non-invasive approach to monitoring cellular pH and detecting changes in response…

Cancer, Hypoxia, and MetabolismLanthanide and Transition Metal ComplexesElectron Spin Resonance Studies

Chemical and paragenetic data on gadolinite-group minerals from Baveno and Cuasso al Monte, southern Alps, Italy

Federicο Pezzotta、Valeria Diella、Alessandro Guastoni1999-06-01American Mineralogist

The crystal structure of a rubidian cesian phlogopite-1M from pegmatite exocontacts at Red Cross Lake, Manitoba, monoclinic, a = 5.343(1),6 = 9.247(2),c = 10.397(3) Å, β = 100.04(2)°, V= 505.8(2) Å 3 , has been refined to an R index of 4.5% based on 519 observed reflections measured with graphite-monochromated MoΚα X-…

Geological and Geochemical AnalysisCrystal Structures and PropertiesRadioactive element chemistry and processing

The effects on polyetheretherketone and polyethersulfone of electron and γ irradiation

H.M. Li、R.A. Fouracre、M.J. Given 等 6 位作者1999-06-01IEEE Transactions on Dielectrics and Electrical Insulation

In this study, the effects of ionizing radiation on the aromatic polymers polyethersulfone (PES) and polyetheretherketone (PEEK) were investigated. UV light, /spl gamma/ rays and a high-energy electron beam were used as radiation sources. A range of techniques has been utilized to investigate changes in PES and PEEK a…

Polymer Nanocomposites and PropertiesHigh voltage insulation and dielectric phenomenaPolymer Nanocomposite Synthesis and Irradiation

Poly(p-phenyleneethynylene)s Are Thermotropic Liquid Crystalline

Lioba Kloppenburg、David Jones、John B. Claridge 等 5 位作者1999-06-01Macromolecules

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTPoly(p-phenyleneethynylene)s Are Thermotropic Liquid Crystalline†Lioba Kloppenburg, David Jones, John B. Claridge, Hans-Conrad zur Loye, and Uwe H. F. BunzView Author Information Department of Chemistry and Biochemistry, The Univers…

Liquid Crystal Research AdvancementsSurfactants and Colloidal SystemsSynthesis and Properties of Aromatic Compounds

Coalescence in blends of thermoplastic polyurethane with polyolefins

Katrin Wallheinke、Petra Pötschke、Christopher W. Macosko 等 4 位作者1999-06-01Polymer Engineering and Science

Abstract The coalescence behavior of immiscible blends was determined by annealing the melt without shear. The kinetics and the mechanism of coalescence were observed for blends of thermoplastic polyurethane (TPU) and polyolefins. Two different types of measurements were used to observe coalescence in quiescent melt a…

Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesPolymer composites and self-healing

Material Selection Guidelines to Limit Atomic Oxygen Effects on Spacecraft Surfaces

D. Dooling、Miria Finckenor1999-06-01NASA Technical Reports Server (NASA)

This report provides guidelines in selecting materials for satellites and space platforms, designed to operate within the Low-Earth orbit environment, which limit the effects of atomic oxygen interactions with spacecraft surfaces. This document should be treated as an introduction rather than a comprehensive guide sin…

Silicone and Siloxane Chemistry

Ab initiostructure determination of sulfathiazole polymorph V from synchrotron X-ray powder diffraction data

Fung Choy Chan、Jamshed Anwar、Robert J. Cernik 等 5 位作者1999-06-01Journal of Applied Crystallography

The crystal structure of sulfathiazole [4-amino- N -(2,3-dihydro-2-thiazolylidene)benzenesulfonamide, C 9 H 9 N 3 O 2 S] polymorphic form V has been determined from high-resolution synchrotron X-ray powder diffraction data. The structure is monoclinic, space group P 2 1 / n , Z = 8, with two molecules in the asymmetri…

Crystallography and molecular interactionsX-ray Diffraction in CrystallographyPolymer Synthesis and Characterization

Organization of cyanobiphenyl liquid crystal molecules in prewetting films spreading on silicon wafers

S. Bardon、R. Ober、Marie‐Pierre Valignat 等 6 位作者1999-06-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics

We observe prewetting films of 8CB (4'-n-octyl-4-cyanobiphenyl) spreading at room temperature on silicon wafers by ellipsometry and x-ray reflectivity. Ellipsometry indicates the formation of a nondense monolayer spreading in front of a 45-A-thick film. X-ray reflectivity, performed using a ribbon geometry for the liq…

Liquid Crystal Research AdvancementsNonlinear Dynamics and Pattern FormationFluid Dynamics and Thin Films

Effect of Grain Size on the Sliding Wear and Friction of Alumina at Elevated Temperatures

Tetsuya Senda、Eiichi Yasuda、Masaki Kaji 等 4 位作者1999-06-01Journal of the American Ceramic Society

The sliding friction and wear of three different grain‐size aluminas were studied from room temperature through 1000°C. The coefficient of friction revealed two distinct regions of decrease with increased temperature, with a transition at ∼700°C. Below 700°C, the coefficient of friction decreased rapidly with increase…

Advanced ceramic materials synthesisAluminum Alloys Composites PropertiesAdvanced materials and composites

Supramolecular Organization of Oligo(m-phenylene ethynylene)s in the Solid-State

P.-J. Prest、Ryan B. Prince、Jeffrey S. Moore1999-06-01Journal of the American Chemical Society

A series of oligo( m -phenylene ethylene)s having triethylene glycol ester-linked side chains (i.e., 2-[2-(2-methoxyethoxy)ethoxy]ethyl esters) were prepared, and their supramolecular organization in the solid-state was studied. These oligomers are amphiphilic, having a nonpolar aromatic hydrocarbon backbone that is a…

Organic Electronics and PhotovoltaicsLuminescence and Fluorescent MaterialsSynthesis and Properties of Aromatic Compounds

Strength of a Hi‐Nicalon™/Silicon‐Carbide‐Matrix Composite Fabricated by the Multiple Polymer Infiltration‐Pyrolysis Process

Michio Takeda、Yutaka Kagawa、Shiro Mitsuno 等 5 位作者1999-06-01Journal of the American Ceramic Society

A woven‐fabric Hi‐Nicalon™‐fiber reinforced SiC‐matrix composite has been fabricated by using a multiple polymer infiltration‐pyrolysis (PIP) process. The three‐point bend strength, at room temperature, of the composite is examined as a function of total porosity of the composite. The porosity of the composite decreas…

Advanced ceramic materials synthesisAluminum Alloys Composites PropertiesFiber-reinforced polymer composites

Low-Fire NiO–CuO–ZnO Ferrite with Bi2O3

Jau‐Ho Jean、Cheng-Horng Lee1999-06-01Japanese Journal of Applied Physics

Additions of Bi 2 O 3 were used to enhance densification and to promote grain growth during sintering of NiO–CuO–ZnO ferrite. With a small amount of Bi 2 O 3 (0.5–2.5 wt%) present as a sintering aid in NiO–CuO–ZnO ferrite, the densification rate and final sintered density are greatly increased, but the activation ener…

Multiferroics and related materialsMagnetic Properties and Synthesis of FerritesMicrowave Dielectric Ceramics Synthesis

Raman scattering studies of monohydrated L-asparagine

A. Moreno、Paulo Freire、I. Guedes 等 6 位作者1999-06-01Brazilian Journal of Physics

Polarized first-order Raman scattering studies at 300 K were carried out in L-asparagine monohydrate crystal in order to obtain the general assignment of its phonon spectra. A careful analysis of the vibrational spectra shows that the assignment of the fundamental vibrational modes can be done on the basis of amino, c…

Crystallography and molecular interactionsNonlinear Optical Materials ResearchSolid-state spectroscopy and crystallography

B3O3Ph3(7-azaindole): Structure, Luminescence, and Fluxionality

Qianying Wu、Gang Wu、Lorenzo Brancaleon 等 4 位作者1999-06-01Organometallics

A 7-azaindole adduct of boroxine, B 3 O 3 Ph 3 (7-azaindole), 1, was obtained from the reaction of PhB(OH) 2 with 7-azaindole. The crystal structure of 1 shows that the 7-azaindole ligand is bonded to the boroxine molecule through a B−N bond and an H···O hydrogen bond. Compound 1 is fluorescent in solution and the sol…

Molecular Sensors and Ion DetectionLuminescence and Fluorescent MaterialsOrganoboron and organosilicon chemistry