Materials Literature
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A tetraphenylporphyrin (1b) bearing amide groups at the 3,5-positions of the meso-phenyl groups is assembled into a two-dimensional sheetlike structure and acts as an organogelator. When [60]fullerene was added, the sheetlike structure was dramatically changed into a one-dimensional fibrous structure, and both the gel…
Local structure of the Fe-doped La$_{1-x}$Ca$_{x}$MnO$_{3}$ (x=0.00-1.00) compounds has been investigated by means of Mössbauer spectroscopy. $^{57}$Fe Mössbauer spectra provide a direct evidence of Jahn-Teller distortion in these manganites. On the basis of Mössbauer results, the Jahn-Teller coupling was estimated. I…
We present a systematic analysis of point-contact Andreev reflection (PCAR) spectra for ferromagnetic materials, using both modeling and experimental data. We consider the relationship between ballistic and diffusive transport, the effect of different transport regimes on spin polarization measurements, and the import…
An analytic representation of the short-range repulsion energy in ionic systems is described that allows for the fact that ions may change their size and shape depending on their environment. This function is extremely efficient to evaluate relative to previous methods of modeling the same physical effects. Using a we…
Our study presents experimental measurements of the contact and longitudinal voltage drops in Hall bars, as a function of the current amplitude. We are interested in the heating phenomenon which takes place before the breakdown of the quantum Hall effect, i.e. the pre-breakdown regime. Two types of samples has been in…
The h_u hole spectral intensity for C60 -> C60+ molecular photoemission is calculated at finite temperature by a parameter-free Lanczos diagonalization of the electron-vibration Hamiltonian, including the full 8 H_g, 6 G_g, and 2 A_g mode couplings. The computed spectrum at 800 K is in striking agreement with gas-phas…
We present detailed first-principles calculations for the normal state electronic properties of the high T$_C$ superconductor Bi$_2$Sr$_2$CaCu$_2$O$_8$, by means of the linearized augmented plane wave (LAPW) method within the framework of density functional theory (DFT). As a first step, the body centered tetragonal (…
We have fabricated carbon-nanotube (CN) field-effect transistors with multiple, individually addressable gate segments. The devices exhibit markedly different transistor characteristics when switched using gate segments controlling the device interior versus those near the source and drain. We ascribe this difference…
Many of the outstanding properties in oxides are related to materials with an intrinsic nanoscaled local structure, where the different regions are characterized by competing chemical, structural, and/or physical properties. One of the major challenges in the analysis of the nanoscaled oxides is experimental access to…
We have performed ab initio calculations within the density-functional theory for Ga_{1-x}Mn_xAs diluted semiconductors. Total energy results unambiguously show that a quasi-localized down-spin hole, with strong p-like character, surrounds the fully polarized Mn up-spin d^5-electrons. Calculations indicate that the ho…
We present high resolution two-photon excitation microscopy studies combining two-photon fluorescence (TPF) and second harmonic generation (SHG) in order to probe orientational distributions of molecular ensembles at room temperature. A detailed polarization analysis of TPF and SHG signals is used in order to unravel…
The Fifth Edition of Principles of Polymer Systems has been completely revised and updated. The chemical engineering perspective has been retained and strengthened, and the broad applications of polymers in chemistry and materials science have been addressed. The theoretical basis for various topics has been deepened…
Synthetic pargasite with near end-member cation stoichiometry (X F = F/((OH) + F) = 0) and natural, gem-quality fluoropargasite from Sri Lanka (X F = 0.605) have been studied by high-temperature lead-borate drop-solution calorimetry under dynamic measuring conditions in flowing Ar. IR-spectroscopy shows that both samp…
Electronic structures of very dilute Cr- or Ru-doped ${\mathrm{Nd}}_{1/2}{A}_{1/2}{\mathrm{MnO}}_{3}$ (NAMO) $(A=\mathrm{Ca},\mathrm{Sr})$ manganites have been investigated using the Mn and Cr $2\stackrel{\ensuremath{\rightarrow}}{p}3d$ resonant photoemission spectroscopy (PES). All the Cr- and Ru-doped NAMO systems e…
A revision of the monoraphid pennate diatom genus Campyloneis Grunow was carried out based on LM and EM observations. The material examined originated from various herbarium collections and from extant epiphytic diatom communities on leaves of Posidonia spp. We also examined the generitype C. grevillei (Smith) Grunow…
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Abstract A fine crystal MoS2 has been synthesized by hydrothermal method in a clean and efficient system consisting of Na2MoO4 and KSCN in a short time (24 h). The product is characterized by XRD and TEM, and the ED pattern reveals a hexagonal crystal. The mechanism of this reaction is also put forward. Thus this meth…
This study deals with the radiation-induced defects in fracture filling clay-minerals from the El Berrocal U-deposit (Spain), which is considered as a natural analogue of a high-level nuclear waste repository in granitic rock. Mineralogical analyses shows the widespread occurrence of dickite as a secondary alteration…
Lipase-catalyzed polymerization of caprolactone (CL) in toluene with methoxy-poly(ethylene glycol) (MPEG) and water as initiators was characterized in detail for mechanistic insight. (1)H NMR analysis of polycaprolactone chains (PCL), dicaprolactone, degree of esterification of MPEG, and fractions of PCL chains initia…
Abstract A combination of NMR and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF) techniques were suitable tools for examining the exchange reactions that occur during the melt‐mixing of nylon‐6 and poly(ethylene terephthalate) (Ny6/PET) blends in the presence of p‐toluene sulf…