En‐Qing Gao、Jinkui Tang、Dai‐Zheng Liao 等 6 位作者2001-05-18Inorganic Chemistry
Four oxamato-bridged heterotrinuclear Ni(II)Cu(II)Ni(II) complexes of formula ([Ni(bispictn)](2)Cu(pba))(ClO(4))(2).2.5H(2)O (1), ([Ni(bispictn)](2)Cu(pbaOH))(ClO(4))(2).H(2)O (2), ([Ni(cth)](2)Cu(pba))(ClO(4))(2) (3), and ([Ni(cth)](2)Cu(opba))(ClO(4))(2).H(2)O (4) and a binuclear Ni(II)Cu(II) complex of formula [Cu(…
Metal complexes synthesis and propertiesMagnetism in coordination complexesMetal-Catalyzed Oxygenation Mechanisms
Stephanie L. Brock、Maria Sanabria、Jaya Nair 等 5 位作者2001-05-18The Journal of Physical Chemistry B
The structure and ion-exchange properties of tetraalkylammonium (TAA; alkyl = methyl, ethyl, propyl) manganese oxide gels produced from colloidal manganese oxide solutions are presented. TAA manganese oxide xerogels are analyzed by X-ray powder diffraction (XRD) and extended X-ray absorption fine spectra (EXAFS) and c…
Supercapacitor Materials and FabricationLanthanide and Transition Metal ComplexesLayered Double Hydroxides Synthesis and Applications
Mark Murrie、H. Stoeckli‐Evans、Hans U. Güdel2001-05-18Angewandte Chemie International Edition
The proligand citric acid has been used to assemble two new anionic NiII clusters, [Ni7(cit)6(H2O)2]10− and [Ni21(cit)12(OH)10(H2O)10]16− (see picture; Ni=black spheres), from basic aqueous solution. The former possesses a high-spin S=7 ground state, while the latter shows predominantly antiferromagnetic exchange.
Metal complexes synthesis and propertiesMagnetism in coordination complexesNanocluster Synthesis and Applications
Mike Wehmeier、Manfred Wagner、Kläus Müllen2001-05-18Chemistry - A European Journal
New perylene chromophores, phenyl-substituted diindeno[1,2,3-cd:1',2',3'-lm]perylenes 5a,b and 4,4',7,7'-tetraphenyldiacenaphtho[1,2-k:1',2',k']diindeno[1,2,3-cd:1',2',3'-me]perylenes 22a,b, have been synthesized from substituted fluoranthene derivatives 3a,b and 4a,b by means of a surprisingly simple oxidative cyclod…
Organic Electronics and PhotovoltaicsLuminescence and Fluorescent MaterialsPhotochromic and Fluorescence Chemistry
Ruikang Tang、George H. Nancollas、Christine A. Orme2001-05-18Journal of the American Chemical Society
Recent constant composition dissolution studies of sparingly soluble calcium phosphates have revealed an interesting and unusual behavior in that the rates decreased, eventually resulting in effective suppression, even though the solutions remained undersaturated. Contrary to traditional theories of dissolution, these…
Metal Extraction and BioleachingCalcium Carbonate Crystallization and InhibitionMinerals Flotation and Separation Techniques
G. Eric Oosterom、Joost N. H. Reek、Paul C. J. Kamer 等 4 位作者2001-05-18Angewandte Chemie
Dendrimere sind wohldefinierte hochverzweigte Makromoleküle, die bei hinreichender Größe charakteristische globuläre Strukturen aufweisen. Sie haben viele Chemiker zur Entwicklung von neuen Materialien angeregt, und eine Reihe von Anwendungen, auch in der Katalyse, wurde bereits untersucht. Die jüngsten Fortschritte b…
RNA Interference and Gene DeliveryChemical Synthesis and AnalysisDendrimers and Hyperbranched Polymers
Takahiro Kusukawa、Michito Yoshizawa、Makoto Fujita2001-05-18Angewandte Chemie International Edition
The highly symmetric structure of a cagelike host enables the inclusion geometry of guest molecules in the host to be predicted in a dynamic fashion by analyzing not the guest but the host framework. For example, an S4 orientation of two 1,2-diketone guests in the clathrate complex was predicted by NMR spectroscopy an…
Crystallography and molecular interactionsPorphyrin and Phthalocyanine ChemistrySpectroscopy and Quantum Chemical Studies
Prafulla Chetri、N. N. Dass2001-05-18Journal of Applied Polymer Science
Abstract Poly(vinyl alcohol) (PVA) can be dissolved in a nonaqueous medium in the presence of catalytic concentration of ethyl nitrate dimethyl sulfoxide, C 2 H 5 ONO 2 · DMSO (EN · DMSO). From the PVA solution, poly(vinyl butyral) (PVBu) was prepared by acid‐catalyzed homogeneous acetalization of PVA with butyraldehy…
Polymer crystallization and propertiesbiodegradable polymer synthesis and propertiesPolymer Science and PVC
Sheng‐Huei Hsiao、Jiun‐Hsiang Chiou2001-05-18Journal of Polymer Science Part A Polymer Chemistry
Abstract Polyhydrazides and poly(amide‐hydrazide)s were prepared from two ether‐sulfone‐dicarboxylic acids, 4,4′‐[sulfonylbis(1,4‐phenylene)dioxy]dibenzoic acid and 4,4′‐[sulfonylbis(2,6‐dimethyl‐1,4‐phenylene)dioxy]dibenzoic acid, or their diacyl chlorides with terephthalic dihydrazide, isophthalic dihydrazide, and p…
Epoxy Resin Curing ProcessesSynthesis and properties of polymersSilicone and Siloxane Chemistry
E. Donth、Heiko Huth、Mario Beiner2001-05-18Journal of Physics Condensed Matter
Three lengths for the dynamic glass transition will be compared: a kinematic length from computer simulation, a heterogeneity length from multidimensional nuclear magnetic resonance, and a characteristic length from calorimetry. A qualitatively consistent picture is obtained after discussion of their different origins…
Material Dynamics and PropertiesThermodynamic properties of mixturesAdsorption, diffusion, and thermodynamic properties of materials
Laura G. Schultz、Yan Zhao、Steven C. Zimmerman2001-05-18Angewandte Chemie International Edition
Hydrolytic removal of the core unit and cross-linking of their wedges enables dendrimers to be “cored” (see schematic representation). By internalizing the alkenes, the ring-closing metathesis reaction will “stitch” the dendritic wedges together intramolecularly, even at dendrimer concentrations of 10−3 M. In contrast…
Chemical Synthesis and AnalysisSynthetic Organic Chemistry MethodsDendrimers and Hyperbranched Polymers
Dong Wuk Kim、W. S. Kim、D. H. Lee 等 8 位作者2001-05-18Journal of Applied Polymer Science
Abstract Prior to curing, we evaluated thermal stability of poly(butylene succinate) (PBS). Above 170°C, PBS was severely degraded and the degradation could not be successfully stabilized by an antioxidant. PBS was crosslinked effectively by DCP at 150°C, and the gel fraction was increased as DCP content increased. Th…
Polymer Nanocomposites and Propertiesbiodegradable polymer synthesis and propertiesAdditive Manufacturing and 3D Printing Technologies
J. D. Maynard2001-05-18Reviews of Modern Physics
As a result of advances in experimental and theoretical physics, many interesting problems have arisen in condensed-matter physics, typically as a result of the quantum-mechanical nature of a system. Areas of interest include Anderson localization, universal conductance fluctuations, normal electron persistent current…
Quasicrystal Structures and PropertiesMineralogy and Gemology Studies
E. A. Jagla2001-05-18Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
A system of identical particles interacting through an isotropic potential that allows for two preferred interparticle distances is numerically studied. When the parameters of the interaction potential are adequately chosen, the system exhibits coexistence between two different liquid phases (in addition to the usual…
Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesPickering emulsions and particle stabilization
Tse‐Hao Ko、Wen‐Shyong Kuo、Ying‐Huang Chang2001-05-18Journal of Applied Polymer Science
Abstract After curing, phenol‐formaldehyde resins were postcured at 230°C in air for 32 h and then carbonized and graphitized from 300 to 2400°C. Thermal fragmentation and condensation of the polymer structure occurred above 300°C. The crystal size of the cured phenolic resins decreased with the temperature increase.…
Carbon Nanotubes in CompositesPolymer Nanocomposites and PropertiesFiber-reinforced polymer composites
Jian Jiang、F. Kragh、D. J. Frost 等 5 位作者2001-05-18Journal of Physics Condensed Matter
The hardness and thermal stability of cubic spinel silicon nitride (c-Si 3 N 4 ), synthesized under high-pressure and high-temperature conditions, have been studied by microindentation measurements, and x-ray powder diffraction and scanning electron microscopy, respectively. The phase at ambient temperature has an ave…
Advanced ceramic materials synthesisMetal and Thin Film MechanicsDiamond and Carbon-based Materials Research
Stephan Haubold、Markus Haase、Andreas Kornowski 等 4 位作者2001-05-18ChemPhysChem
The wide-bandgap semiconducting material, zinc sulfide, has been coated on indium phosphide nanoclusters to a 1-2-Å thickness. The resulting InP-ZnS core-shell particle (as shown in the TEM image; scale 1 cm=5 nm) exhibits bright luminescence at room temperature with quantum efficiencies as high as 23 %.
Quantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin FilmsNanocluster Synthesis and Applications
Lars Dähne、Stefano Leporatti、Edwin Donath 等 4 位作者2001-05-18Journal of the American Chemical Society
Hollow polyelectrolyte capsules in micro- and submicrometer size were prepared. Their interior was functionalized by a "ship in bottle" synthesis of copolymers. While the monomers permeated the capsule wall easily, the formed polymers remained in the capsule cage. The physicochemical properties of the capsule interior…
Polymer Surface Interaction StudiesMolecular Junctions and NanostructuresDendrimers and Hyperbranched Polymers
Alfons M. Molenbroek、Jens K. Nørskov、Bjerne S. Clausen2001-05-18The Journal of Physical Chemistry B
We discuss the design of a Ni−Au nanoparticle catalyst system, which is based on the detailed experimental and theoretical understanding of the alloying and the chemical reaction processes on single-crystal surfaces. The alloy formation and structure of Ni−Au catalysts supported on SiO 2 and on MgAl 2 O 4 are simulate…
Catalytic Processes in Materials ScienceCatalysts for Methane Reformingnanoparticles nucleation surface interactions
Siegfried O. H. Gutschke、D.J. Price、Annie K. Powell 等 4 位作者2001-05-18Angewandte Chemie International Edition
Corner-sharing Co3(μ3-OH) triangles make up the framework of two novel compounds obtained by hydrothermal synthesis from CoCl2, NaOH, and benzene-1,2,3-tricarboxylic acid. In the structure (see picture) of one of these—[Co2(OH){1,2,3-(O2C)3C6H3}(H2O)]⋅H2O—octahedral (crosshatched) and tetrahedral (dotted) Co sites alt…
Metal-Organic Frameworks: Synthesis and ApplicationsMagnetism in coordination complexesPolyoxometalates: Synthesis and Applications