Materials Literature
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For the first time pressure-volume-temperature (PVT) measurements for the crystal-like smectic E phase have been performed. The phase diagram of 4′-n -octyl-4-isothiocyanatobiphenyl 8BT has been recently established using differential thermal analysis up to 250 MPa. 8BT exhibits a splitting of the clearing line above…
The oxidation of p-toluidine in acetonitrile by hydrogen peroxide is a very slow reaction which produces 4,4'-dimethylazoxybenzene as the product. The presence of functionalized multiwalled carbon nanotubes (CNT) in the above reaction produces 4,4'-dimethylazobenzene. The reactions have been followed by GC/MS, which s…
In the present publication we report on the preparation and spectroscopic features of a penta-coordinate rhodium(III) complex of corrole with bulky ortho-phenyl substituents at the meso positions, Rh ( tdcc )( PPh 3 )[ tdcc = tris (2,6- dichlorophenyl ) corrole ]. Addition of pyridine to Rh ( tdcc )( PPh 3 ), as well…
Microphase separation and morphology of asymmetric diblock copolymer (f = 0.4) thin films confined in a slit with surfaces neutral or attractive towards block A or block B were studied by the cell dynamic system method (CDS). The size effect in CDS calculations was carefully investigated. For asymmetric copolymers, th…
A new method of assessing the magnitude of the magnetic field in a transmission electron microscope using a permanent magnetic material is described. The approach is versatile and simple enough to be implemented for certain scientific or engineering situations in which the exact calibration of the magnetic field in th…
The structure and bonding in oxidized and reduced decatungstate anions have been investigated using density-functional methods. The computational−experimental agreement is good for the geometrical parameters of the oxidized species. The electronic structure of the anions has been probed with molecular-orbital, Mullike…
Des investigations portant sur le genre Diadesmis (Bacillariophycées), observé à l'aide du microscope photonique et du microscope électronique à balayage, ont été réalisées dans différents biotopes des archipels de Crozet et de Kerguelen : lacs, mares temporaires, mousses et sols. Dix espèces ont été recensées. Diades…
Abstract Amorphous silicate sediments comprise most of the upper part of the sedimentary column of the Atlantis II Deep, whereas more crystalline phases are found in the lower part. The objective of this study was to focus on the newly-formed, metastable, hydrothermal phases, that eventually transform into clays or Fe…
The linear triplet structure of SiC3 (with terminal Si) has been investigated using coupled cluster methods, including a perturbative treatment of triple excitations, and Dunning’s correlation-consistent polarized core-valence quadrupole zeta basis set (CCSD(T)/cc-pCVQZ). Based on the demonstrated convergence with res…
We report on the evolution of the Raman-active A g phonon modes in the charge-ordered manganite Pr 0.63 Ca 0.37 MnO 3 as a function of temperature from 300 K to 25 K. Our studies reveal that the linewidths of the A g (2) and A g (4) phonons increase as temperature decreases. This anomalous temperature dependence of ph…
Megakalsilite, KAlSiO4, hexagonal, a 18.1111(8), c 8.4619(4) Å, V 2403.7(2) Å3, c:a = 0.4672, space group P63, Z = 24, R = 0.039 (for 3255 observed reflections collected with a four-circle X-ray diffractometer), is a new mineral species from Mount Koashva, Khibina alkaline massif, Kola Peninsula, Russia. It is of pegm…
The correlation between chemical structure and mesomorphic properties is one of the most important problems in liquid crystals science. 3,5-Disubstituted 1,2,4-oxadiazoles are very convenient model-compounds for studying the dependence of the LC properties on the molecular design. The transition temperatures and diele…
Theoretical studies of β-C3N4 and other crystalline carbon nitride structures indicate that several crystalline phases are metastable, with high bulk modulus values. There are many reports of successful synthesis of some crystalline carbon nitride phases. In spite of questionable data analysis in a significant number…
Abstract Morphological characteristics and mechanical properties of PP‐EP/EVA blends were studied and compared to those of PP/EVA previously reported. For the PPEP/EVA blends, interfacial interactions in amorphous zones, which were associated with shifts in T g , were well defined compared to those of PP/EVA blends, a…
On the basis and with the inclusion of results described in a previous paper [2], submitted for publication almost two years ago, we add some comments on very recent developments regarding both the design and synthesis of thermotropic nematogens of low-molecular weight, supposed biaxial in character, as well as puzzle…
Abstract The present work reports evolution of morphology from initial (presence of striation) to final (droplet formation) stages in a single‐screw extruder. Morphology development during the blending process controls the final size of the dispersed phase, which in turn significantly affects the properties of the ble…
Better understanding of mineral surface reactivity can improve control of crystal growth and dissolution which is central to biomineralisation, design of advanced materials and preventing transport of toxic substances in the environment. Some experimental observations of fundamental processes on calcite using high-res…
The new Heraeus STU fiber, which is very similar to the radiation resistant Russian KS-4V fiber, was subjected to /sup 60/Co gamma irradiation tests for the first time. The results of spectral measurements (300-850 nm) as well as of measurements at 829 and 1310 nm with different dose rates were compared with those of…
The slow growth characteristics of a condensing ethanol sessile drop on a quartz substrate were studied experimentally. Using interference microscopy measurements of the transient liquid film profile (curvature) to obtain the pressure field and a Kelvin−Clapeyron model of interfacial mass flux to obtain the interfacia…
One hundred and thirty samples from the collection of the Natural History Museum in Florence, labeled as tetrahedrite, have \nbeen extensively studied by means of SEM, XRD, EPMA, DTA, EPR and SQUID techniques. Wide-ranging substitutions, \nconfirmed by compositional data, play a fundamental role in the thermal…