R. Gerdil、Huiyou Liu、G. Bernardinelli1999-03-10Helvetica Chimica Acta
Several aspects of the heterogeneous actions of aqueous and gaseous HCl on the chemical behavior of 3,4-epoxycyclopentanone (=6-oxabicyclo[3.1.0]hexan-3-one; 1) included in the asymmetric cages of tri-o-thymotide (TOT) clathrates belonging to space groups P3121 are described, showing specific features strikingly at va…
Mesoporous Materials and Catalysis
Edwin Suresh、John Pragasam、Francis P. Xavier 等 4 位作者1999-03-10International Journal of Energy Research
Manganese–molybdenum–diethyldithiocarbamate [MnMoO2(Et2dtc)4(H2O)] {Et2dtc=diethyldithiocarbamate} complex has exhibited reversible photogalvanic behaviour in aqueous dimethylformamide medium when studied in a Honda cell. The photogalvanic behaviour has been further investigated by varying the pH, temperature and phot…
Magnetism in coordination complexesMetalloenzymes and iron-sulfur proteinsPolyoxometalates: Synthesis and Applications
Giovanni Nisato、Brett D. Ermi、Jack F. Douglas 等 4 位作者1999-03-10Macromolecules
The phase separation kinetics of ultrathin deuterated poly(styrene)/poly(butadiene) polymer blend films spun cast onto striped self-assembled monolayer (SAM) substrates is studied by atomic force microscopy (AFM). Fourier transform analysis of the AFM topographic data at various stages of the film pattern development…
Surfactants and Colloidal SystemsBlock Copolymer Self-AssemblyFluid Dynamics and Thin Films
Giampaolo Ricciardi、Angela Rosa、Ilaria Ciofini 等 4 位作者1999-03-10Inorganic Chemistry
The Co(OESPz) complex crystallizes in space group P 2 1 / n, with a = 10.260(5) Å, b = 22.650(5) Å, c = 16.720(5) Å, β = 91.680(5)°, and Z = 4 and forms, similarly to the isomorphous Mn(OESPz), solid-state extended one-dimensional aggregates where “ruffled” molecular units are held together by extra planar Co···S inte…
Metal-Catalyzed Oxygenation MechanismsMagnetism in coordination complexesPorphyrin and Phthalocyanine Chemistry
Gang Yang、Mitsutoshi Jikei、Masa‐aki Kakimoto1999-03-10Macromolecules
Previous experiments from our group [ Macromolecules 1998, 31, 5964] have established that thermal polymerization of 3,5-bis(4-aminophenoxy)benzoic acid (monomer 1 ) gave a hyperbranched aromatic polyamide (polymer 1 ). Here we show that thermal polymerization of methyl 3,5-bis(4-aminophenoxy)benzoate (monomer 2 ), ha…
Dendrimers and Hyperbranched PolymersSynthesis and properties of polymersRNA Interference and Gene Delivery
Markus Biesalski、J. Rühe1999-03-10Macromolecules
A novel concept for the synthesis of molecularly thin polyelectrolyte layers covalently attached to planar solid surfaces is introduced. The polymer monolayers are generated directly at the surface by using self-assembled monolayers of an azo initiator and radical chain polymerization in situ. This “grafting from” app…
Force Microscopy Techniques and ApplicationsPolymer Surface Interaction StudiesMolecular Junctions and Nanostructures
Marco Fornari、David J. Singh1999-03-10arXiv
The prospects for high thermoelectric performance in phosphide skutterudites are investigated based on first principles calculations. We find that stoichiometric CoP_3 differs from the corresponding arsenide and antimonide in that it is metallic. As such the band structure must be modified if high thermopowers are to…
Materials Science
Ruslan L. Davidchack、Brian. B. Laird1999-03-10arXiv
We examine, using molecular dynamics simulation, the structure and thermodynamics of the (100) and (111) disordered face-centered cubic (FCC) crystal/melt interfaces for a binary hard-sphere system. This study is an extension of our previous work, [Phys. Rev. E 54, R5905 (1996)], in which preliminary data for the (100…
cond-mat.stat-mechMaterials Science
S. Pilla、J. A. Hamida、K. A. Muttalib 等 4 位作者1999-03-10arXiv
We report the first audio frequency dielectric constant measurements of CO and N_2 in their solid phases. We have observed several new features, including (1) strong hysteresis effects above an onset temperature $T_{h} \simeq 42 K$ in the β-phase of pure N_2, (2) absence of the expected short range antiferroelectric d…
Materials Science
I. Terasaki、Y. Sasago、K. Uchinokura1999-03-10arXiv
A transition-metal oxide NaCo_2O_4 is a layered oxide in which CoO_2 and Na alternately stack along the c axis. Recently we have found that this compound shows unusually large thermopower with low resistivity, which is comparable to those of Bi_2Te_3. The negative transverse magnetoresistance and the strongly temperat…
Materials ScienceStrongly Correlated Electrons
E. G. Mishchenko1999-03-10arXiv
The inelastic light scattering in a 2-d electron gas is studied theoretically using the Boltzmann equation techniques. Electron-hole excitations produce the Raman spectrum essentially different from the one predicted for the 3-d case. In the clean limit it has the form of a strong non-symmetric resonance due to the sq…
Mesoscale and Nanoscale PhysicsMaterials Science
J. H. K. Ky Hirschberg、F.H. Beijer、Huub A. van Aert 等 6 位作者1999-03-10Macromolecules
Telechelic oligo- and poly(dimethylsiloxanes) 1 and 2, with two ureidopyrimidone (UPy) functional groups, have been prepared via a hydrosilylation reaction. The compounds have been characterized in solution by 1 H NMR and viscometry and in the solid state by 1 H NMR and 13 C NMR, FTIR, and rheology measurements. The m…
Advanced Sensor and Energy Harvesting MaterialsPolymer composites and self-healingSilicone and Siloxane Chemistry
Jae Hee Song、Michael J. Sailor1999-03-09Inorganic Chemistry
Exposure of photoluminescent porous Si to alkyllithium reagents results in grafting of the alkyl group to the silicon surface by formation of a Si−C bond. The reaction is proposed to proceed by addition of the alkyllithium reagent across a surface Si−Si bond, forming Si−alkyl and Si−Li surface species. The highly reac…
Luminescence Properties of Advanced MaterialsSemiconductor materials and devicesSilicon Nanostructures and Photoluminescence
Jürgen Horbach、Walter Kob、Kurt Binder1999-03-09The Journal of Physical Chemistry B
We investigate to what extent the specific heat of amorphous silica can be calculated within the harmonic approximation. For this we use molecular dynamics computer simulations to calculate, for a simple silica model (the BKS potential), the velocity autocorrelation function and hence an effective density of states g…
High-pressure geophysics and materialsGlass properties and applicationsMaterial Dynamics and Properties
Pablo Jensen1999-03-09arXiv
This paper presents a comprehensive analysis of simple models useful to analyze the growth of nanostructures obtained by cluster deposition. After detailing the potential interest of nanostructures, I extensively study the first stages of growth (the submonolayer regime) by kinetic Monte-Carlo simulations. These simul…
Mesoscale and Nanoscale PhysicsMaterials Science
Nicola Marzari、David Vanderbilt、Alessandro De Vita 等 4 位作者1999-03-09arXiv
Al(110) has been studied for temperatures up to 900 K via ensemble density-functional molecular dynamics. The strong anharmonicity displayed by this surface results in a negative coefficient of thermal expansion, where the first interlayer distance decreases with increasing temperature. Very shallow channels of oscill…
Materials Science
Tomohiro Hashimoto、Yoong‐Kee Choe、Haruyuki Nakano 等 4 位作者1999-03-09The Journal of Physical Chemistry A
The multireference Møller−Plesset perturbation (MRMP) theory with complete active space self-consistent field (CASSCF) reference functions is applied to the study of the Q and B bands of free-base, magnesium, and zinc porphyrins and their derivatives. The Q band of free-base porphyrin is so weak because the transition…
Photochemistry and Electron Transfer StudiesPorphyrin and Phthalocyanine ChemistryPhotosynthetic Processes and Mechanisms
Frank Caruso、Heinz Lichtenfeld、Edwin Donath 等 4 位作者1999-03-09OpenAlex
The electrostatic binding of two anionic probe molecules, pyrenetetrasulfonic acid (4-PSA) and 6-carboxyfluorescein (6-CF), to poly(allylamine hydrochloride) (PAH)/poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC)/PSS ultrathin multilayer films assembled onto polystyrene (PS) l…
Analytical Chemistry and SensorsMolecular Junctions and NanostructuresPolymer Surface Interaction Studies
L. H. Thompson、L. K. Doraiswamy1999-03-09OpenAlex
Sonochemistry is the use of ultrasound to enhance or alter chemical reactions. Sonochemistry in the true sense of the term occurs when ultrasound induces “true” chemical effects on the reaction system, such as forming free radicals which accelerate the reaction. However, ultrasound may have other mechanical effects on…
Chemical Reactions and IsotopesCrystallization and Solubility StudiesUltrasound and Cavitation Phenomena
Angel Romo‐Uribe、Alan H. Windle1999-03-08Proceedings of the Royal Society A Mathematical Physical and Engineering Sciences
In situ optical microscopy, small–angle light–scattering and X–ray–scattering techniques have been applied to study flow–induced textures in main–chain thermotropic liquid–crystalline polymers (LCPs). In order to gain more insight into the underlying mechanism leading to the formation of microstructure, the effect of…
Rheology and Fluid Dynamics StudiesAdvanced Materials and MechanicsLiquid Crystal Research Advancements