Search results for "TRANSMISSION ELECTRON"
showing 10 items of 426 documents
Elektronenmikroskopische Untersuchung von Transversalschnitten d�nner Schichten auf festen Unterlagen
1969
A method is described which allows to prepare transverse sections of thin films by means of an ion etching technique so that transmission electron micrographs of the film structure can be carried out. A section through a 6-layered optical film with a total thickness of 0.62 μm is shown as an example.
Nature and origin of natural Zn clay minerals from the Bou Arhous Zn ore deposit: Evidence from electron microscopy (SEM-TEM) and stable isotope comp…
2016
International audience; Zn-clay minerals have been found in the non-sulfide deposit of Bou Arhous (High Atlas, Morocco). They occur as white or ochre clays embedding willemite (Zn2SiO4) and are commonly associated to red detrital clays in karstic cavities. Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) with Energy Dispersive X-ray (EDX) analyses were combined in order to characterize the clay minerals and to determine the mechanism of their formation. XRD patterns on oriented and powdered clays and Fourier Transform Infrared (FTIR) spectroscopic analyses suggest that fraipontite is the major Zn clay phase (with some smectite interstrat…
Asymmetric tungsten oxide nanobrushes via oriented attachment and Ostwald ripening
2011
Tungsten oxide nanobrushes were synthesized using a solvothermal approach that lead to self-branching in the presence of citric acid and hexadecylamine as surfactants. Our synthetic approach yielded branched nanorods of tungsten oxide in a single synthetic step. Based on our results, we propose a phenomenological pathway for the formation, branching, and assembly of these tungsten oxide brushes. The formation of tungsten oxide brushes proceeds by thermal decomposition of ammonium tungstate in the presence of citric acid and hexadecylamine. The pale blue powder obtained after solvothermal reaction was analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolu…
Étude par microscopie électronique et spectroscopie de films minces catalytiques pour micro piles à combustibles
2016
Předložená dizertační práce se zabývá studiem nových katalyzátorů na bázi kov-oxid vhodných pro použití v palivových článcích na straně anody. Platinou dopovaný oxid ceru připravený magnetronovým naprašováním ve formě tenkých vrstev na uhlíkových mezivrstvách nesených křemíkovým substrátem byl zkoumán prostřednictvím mikroskopických a spektroskopických metod. Vliv složení uhlíkového nosiče (a-C a CNx filmy), depozičního času CeOx vrstvy a dalších depozičních parametrů, např. depoziční rychlosti, složení pracovní atmosféry a Pt koncentrace na morfologii Pt-CeOx vrstev byl studován převážně pomocí transmisní elektronové mikroskopie (TEM). Získané výsledky ukazují, že vhodnou kombinací depozič…
A light and electron microscope study of spherical structures in the test cells of an ascidianCiona intestinalis L.
1984
Spherical structures in the test cells that surround the embryos of the ascidianCiona intestinalis L. (Tunicata, phylum Chordata) were studied by both light and electron microscope. Our data support the view that these structures are microorganism-like cells living in symbiosis with the test cells. Their possible role is discussed.
Structural modulations and phase transitions in β-eucryptite: an in-situ TEM study
1999
Beta-eucryptite as grown by the flux method has been investigated by in-situ cold- and hot-stage transmission electron microscopy (TEM). Using electron diffraction and dark-field TEM imaging, we found no evidence for the merohedral twinning that accompanies structural collapse at the β-to-α-quartz transition, suggesting a true hexagonal symmetry for the aluminosilicate framework of β-eucryptite. Selected-area electron diffraction (SAED) patterns exhibited a variety of incommensurate structures along the three a axes with an average modulation period of about 6.5 a. These modulated structures arise from superperiodic stacking parallel to (100) of two structural units with different Li config…
Phase transitions and upconversion luminescence in oxyfluoride glass ceramics containing Ba4Gd3F17 nanocrystals
2017
This is the peer reviewed version of the following article: G. Krieke, A. Sarakovskis, R. Ignatans, J. Gabrusenoks "Phase transitions and upconversion luminescence in oxyfluoride glass ceramics containing Ba4Gd3F17 nanocrystals", Journal of the European Ceramic Society, 2017, 37 (4), which has been published in final form at https://www.sciencedirect.com/science/article/abs/pii/S0955221916306768 This article may be used for non-commercial purposes in accordance with Elsevier Terms and Conditions for Sharing and Self-Archiving.
Nanosized shape-changing colloids from liquid crystalline elastomers.
2010
A method to prepare shape-changing nanospheres from liquid crystalline elastomers is reported. The nanosized colloids are prepared by a miniemulsion process. During this process, colloids are prepared from a liquid crystalline (LC) main-chain polyester and subsequently crosslinked into a nanometer-sized LC elastomer. The ability of these LC elastomers to change their shape at the phase transition temperature from the smectic A to the isotropic phase was detected by temperature-dependent transmission electron microscopy. The phase transition-induced shape change leads to strongly shape anisotropic nanosized elastomer particles.
Optimization of Innovative Three-Dimensionally-Structured Hybrid Vesicles to Improve the Cutaneous Delivery of Clotrimazole for the Treatment of Topi…
2019
New three-dimensionally-structured hybrid phospholipid vesicles, able to load clotrimazole in a high amount (10 mg/mL), were obtained for the first time in this work by significantly reducing the amount of water (&le
Structural Analysis and Photocurrent Spectroscopy of CCCs on 99.99% Aluminum
2003
A characterization of chromate conversion coatings (CCCs) formed in the presence and in the absence of accelerator (ferroferricyanide redox couple) has been performed by various techniques (transmission electron microscopy, TEM, glow discharge optical emission spectrometry, GDOES, X-ray absorption near-end structure, XANES, and photon correlation spectroscopy). The results of a detailed investigation on morphological, compositional, and solid-state properties of freshly converted aluminum samples at different immersion times (30 s-90 min) are reported. The TEM and GDOES data suggest the presence of iron-cyanide species only in the external layer of CCC of nearly constant thickness. The XANE…