Kristofer J. Thurecht、Andreas Heise、Matthijs deGeus 等 7 位作者2006-10-20Macromolecules
The kinetics of enzymatic ring-opening polymerization (eROP) of ε-caprolactone in supercritical carbon dioxide (scCO 2 ) was investigated using a new, high-pressure sampling autoclave. The polymerization was performed using Candida antarctica lipase B (CALB) as catalyst and was found to be approximately first order wi…
Enzyme Catalysis and ImmobilizationCarbon dioxide utilization in catalysisbiodegradable polymer synthesis and properties
Nicola M. Pugno2006-10-20Nanotechnology
In this paper, we evaluate the strength, toughness and stiffness of super-nanotubes, just recently discovered, and of the related fibre-reinforced composites. The prediction of huge toughening mechanisms suggests the feasibility of ‘super-composites'. We found the optimum for super-nanotubes with a number of ∼2 hierar…
Advanced Materials and MechanicsCalcium Carbonate Crystallization and Inhibition
Weiliu Fan、Xinyu Song、Yuxiang Bu 等 5 位作者2006-10-20The Journal of Physical Chemistry B
Selective-controlled structure and shape of LaVO(4) nanocrystals were successfully synthesized by a simple hydrothermal method without the presence of catalysts or templates. It was found that tuning the pH of the growth solution was a crucial step for the control of the structure transformation, that is, from monocli…
Quantum Dots Synthesis And PropertiesLuminescence Properties of Advanced MaterialsAdvanced Photocatalysis Techniques
P. J. Brown、Tapan Chatterji2006-10-20Journal of Physics Condensed Matter
We have undertaken a new study of the magnetic and crystalline structures of YMnO 3 and HoMnO 3 using neutron diffraction combined with neutron polarimetry. It is shown how the long-standing problem of distinguishing between magnetic structure models which give nearly identical diffraction intensities may be resolved.…
Magnetic and transport properties of perovskites and related materialsAdvanced Condensed Matter PhysicsMultiferroics and related materials
Yan Geng、Dennis E. Discher、Justyna Justynska 等 4 位作者2006-10-20Angewandte Chemie International Edition
The attachment of a hydrophobic peptide onto polybutadiene-block-poly(ethylene oxide) shifts the assembly morphologies in water towards those with lower curvatures, namely, from spherical micelles to wormlike micelles and vesicles (see picture; wEO: weight fraction of the hydrophilic PEO block; PEO=poly(ethylene oxide…
Dendrimers and Hyperbranched PolymersAdvanced Polymer Synthesis and CharacterizationSupramolecular Self-Assembly in Materials
Carol Creutz、Bruce S. Brunschwig、Norman Sutin2006-10-20The Journal of Physical Chemistry B
Interfacial charge-transfer absorption (IFCTA) provides information concerning the barriers to charge transfer between molecules and the energy levels of a metal/semiconductor and the magnitude of the electronic coupling and could thus provide a powerful tool for understanding interfacial charge-transfer kinetics. Her…
Quantum Dots Synthesis And PropertiesElectrochemical Analysis and ApplicationsMolecular Junctions and Nanostructures
K. P. Sinha、A. Meulenberg2006-10-20arXiv
Models to account for the observed experimental results for low-energy nuclear reactions in palladium-deuteride systems are presented along with calculated results. The crucial idea is a mechanism of improved probability for the needed penetration of the Coulomb barrier for a D-D reaction. This facilitation occurs, in…
Materials Sciencephysics.plasm-phcond-mat.other
W. Hellmann、R. Hennig、S. Goedecker 等 6 位作者2006-10-20arXiv
Density functional and quantum Monte Carlo calculations challenge the existence of a unique ground state structure for certain Si clusters. For Si clusters with more than a dozen atoms the lowest ten isomers are close in energy and for some clusters entropic effects can change the energetic ordering of the configurati…
Materials Science
V. A. Shalygin、H. Diehl、Ch. Hoffmann 等 11 位作者2006-10-20arXiv
We report on the study of spin photocurrents in (110)-grown quantum well structures. Investigated effects comprise the circular photogalvanic effect and so far not observed circular photon drag effect. The experimental data can be described by an analytical expression derived from a phenomenological theory. A microsco…
Mesoscale and Nanoscale PhysicsMaterials Science
Takeo Hoshi、Takeo Fujiwara2006-10-20arXiv
Fundamental theories and practical methods for large-scale electronic structure calculations are given, in which the computational cost is proportional to the system size. Accuracy controlling methods for microscopic freedoms are focused on two practical solver methods, Krylov-subspace method and generalized-Wannier-s…
Materials Science
S. A. Prosandeev、L. Bellaïche2006-10-20Physical Review Letters
An atomistic approach is used to investigate finite-temperature properties of ferroelectric nanodots that are embedded in a polarizable medium. Different phases are predicted, depending on the ferroelectric strengths of the material constituting the dot and of the system forming the medium. In particular, novel states…
Ferroelectric and Piezoelectric MaterialsDielectric materials and actuatorsMaterial Dynamics and Properties
J. Lloyd-Hughes、S. K. E. Merchant、F. Lan 等 7 位作者2006-10-20arXiv
The carrier dynamics of photoexcited electrons in the vicinity of the surface of (NH4)2S-passivated GaAs were studied via terahertz (THz) emission spectroscopy and optical-pump THz-probe spectroscopy. THz emission spectroscopy measurements, coupled with Monte Carlo simulations of THz emission, revealed that the surfac…
Materials Science
A. P. Sorini、J. J. Kas、J. J. Rehr 等 5 位作者2006-10-20Physical Review B
A method is presented for first-principles calculations of electron inelastic mean free paths and stopping powers in condensed matter over a broad energy range. The method is based on ab initio calculations of the dielectric function in the long wavelength limit using a real-space Green's function formalism, together…
Semiconductor materials and devicesElectron and X-Ray Spectroscopy TechniquesSurface and Thin Film Phenomena
S. S. Rao、Saurabh Tripathi、Dhananjai Pandey 等 4 位作者2006-10-20Physical Review B
${\mathrm{Nd}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_{3}$ nanoparticles (average diameter $\ensuremath{\sim}20$ and $40\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$) are synthesized by the polymeric precursor sol-gel method and characterized by various physico-chemical techniques. Quite strikingly, in the $20\phantom{\rule…
Advanced Condensed Matter PhysicsMultiferroics and related materialsMagnetic and transport properties of perovskites and related materials
Clare J. Dibble、Michael Kogan、Michael J. Solomon2006-10-20Physical Review E
Transitions in structural heterogeneity of colloidal depletion gels formed through short-range attractive interactions are correlated with their dynamical arrest. The system is a density and refractive index matched suspension of 0.20 volume fraction poly(methyl methacyrlate) colloids with the nonadsorbing depletant p…
Phase Equilibria and ThermodynamicsSurfactants and Colloidal SystemsMaterial Dynamics and Properties
Kenneth G. Libbrecht2006-10-20arXiv
This application note describes how to model diffusion-limited crystal growth from vapor using QuickField - a commercial finite-element analysis code. The crystal growth problem is cast into the format of a steady-state heat diffusion problem, which is one type of problem QuickField is designed to solve, and we derive…
Materials Science
Jayant Khandare、Sreeja Jayant、Ajay Singh 等 7 位作者2006-10-20Bioconjugate Chemistry
The relative difference in polymeric architectures of dendrimer and linear bis(poly(ethylene glycol)) (PEG) polymer in conjugation with paclitaxel has been described. Paclitaxel, a poorly soluble anticancer drug, was covalently conjugated with PAMAM G4 hydroxyl-terminated dendrimer and bis(PEG) polymer for the potenti…
RNA Interference and Gene DeliveryDendrimers and Hyperbranched PolymersAdvanced Polymer Synthesis and Characterization
A. Sundaresan、R. Bhargavi、N. Rangarajan 等 5 位作者2006-10-20arXiv
Room-temperature ferromagnetism has been observed in nanoparticles $(7--30\phantom{\rule{0.3em}{0ex}}\mathrm{nm}\phantom{\rule{0.2em}{0ex}}\mathrm{diam})$ of nonmagnetic oxides such as ${\mathrm{CeO}}_{2}$, ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$, $\mathrm{ZnO}$, ${\mathrm{In}}_{2}{\mathrm{O}}_{3}$, and ${\mathrm{SnO}}_{2…
ZnO doping and propertiesMagnetic and transport properties of perovskites and related materialsCopper-based nanomaterials and applications
David Schurig、Jack J. Mock、B.J. Justice 等 7 位作者2006-10-20OpenAlex
A recently published theory has suggested that a cloak of invisibility is in principle possible, at least over a narrow frequency band. We describe here the first practical realization of such a cloak; in our demonstration, a copper cylinder was "hidden" inside a cloak constructed according to the previous theoretical…
Advanced Antenna and Metasurface TechnologiesAntenna Design and AnalysisMetamaterials and Metasurfaces Applications
Hemant S. Patel、Keshav Patel2006-10-19International Journal of Polymeric Materials
Eight homopolyesters were synthesized by high temperature polycondensation of 2-(N-1-naphthylamine)-4,6-bis (naphthoxy-2-carbonyl chloride)-s-triazine [NANCCT]with each of the eight diols: Bisphenol-A(BPA), bisphenol-C(BPC), phenolphthalein(ph), resorcinol(R), hydroquinone(Hq), catechol(C), 1,5-dihydroxy naphthalene (…
Synthesis and properties of polymersSynthesis and Characterization of Heterocyclic CompoundsEpoxy Resin Curing Processes