Graphene and hexagonal boron nitride (hBN) are two-dimensional (2D) materials with a similar atomic structure but drastically different although complementary electronic properties. The large-scale synthesis of h-BN/graphene heterostructures with high crystallographic quality is required to fully benefit of the graphene electronic properties. In this study, we examine numerically the interaction of graphene precursors on hBN and of hBN precursors on graphene to gain deep insight of the CVD and MBE growth mechanism of graphene/hBN heterostructures.
View Article and Find Full Text PDFFor the fabrication of modern graphene devices, uniform growth of high-quality monolayer graphene on wafer scale is important. This work reports on the growth of large-scale graphene on semiconducting 8 inch Ge(110)/Si wafers by chemical vapor deposition and a DFT analysis of the growth process. Good graphene quality is indicated by the small FWHM (32 cm) of the Raman 2D band, low intensity ratio of the Raman D and G bands (0.
View Article and Find Full Text PDFThis paper discusses the state of advancement in the development of spectroscopic methods based on the use of mid (proper) infrared radiation in the context of applications in various fields of science and technology. The authors drew attention to the most important solutions specific to both spectroscopy itself (ATR technique) and chemometric data processing tools (PCA and PLS models). The objective of the current paper is to collect and consistently present information on various aspects of FT-IR spectroscopy, which is not only a well-known and well-established method but is also continuously developing.
View Article and Find Full Text PDFThe growth of hexagonal boron nitride (hBN) on epitaxial Ge(001)/Si substrates via high-vacuum chemical vapor deposition from borazine is investigated for the first time in a systematic manner. The influences of the process pressure and growth temperature in the range of 10-10 mbar and 900-980 °C, respectively, are evaluated with respect to morphology, growth rate, and crystalline quality of the hBN films. At 900 °C, nanocrystalline hBN films with a lateral crystallite size of ~2-3 nm are obtained and confirmed by high-resolution transmission electron microscopy images.
View Article and Find Full Text PDFMost publications on the influence of environmental factors on macroinvertebrate communities focus on large rivers, whereas relatively few examine small watercourses in agricultural areas, which, due to their size and pressure from intensive agricultural production, are much more susceptible to the effects of unfavourable environmental conditions or anthropopressure. The aim of our study was to compare the biodiversity of macrozoobenthos assemblages and to determine the effects of physicochemical and hydrological conditions on their abundance and density in 10 small rivers in agricultural areas located in northwest (53°23' N 15°14' E) and central (52°11' N 20°48' E) Poland. In total, 105 taxa were recorded, with the majority being euryoecious.
View Article and Find Full Text PDFRound goby Neogobius melanostomus (Pallas 1814) has become a significant component in the diet of piscivorous fish from the Pomeranian Bay (Bornholm Basin, Baltic Sea). Proper identification of fish species in the diet of predators is significant in biological studies of fish and other aquatic animal species, and, with regard to N. melanostomus, it is important to the knowledge of trophic web structures in areas this species has invaded.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2020
The oxidation behavior of Ge(001) and Ge(110) surfaces underneath the chemical vapor deposition (CVD)-grown graphene films has been investigated experimentally and interpreted on the basis of ab initio calculations. Freshly grown samples were exposed to air for more than 7 months and periodically monitored by X-ray photoelectron spectroscopy, scanning electron microscopy, and Raman spectroscopy. The oxidation of Ge(110) started with incubation time of several days, during which the oxidation rate was supposedly exponential.
View Article and Find Full Text PDFPleomorphic adenoma, also known as tumor mixtus, is one of the most common types of benign neoplasm of the salivary gland, which presents as a slow growing, painless tumor. Major salivary glands are the typical localization of this neoplasm. It rarely undergoes malignant transformation, however may recur locally post resection.
View Article and Find Full Text PDFWstęp: Nowotwory mające swoją etiologię w gruczołach ślinowych występują rzadko i stanowią ok. 3-10% wszystkich guzów w obrębie głowy i szyi. Materiał i metody: W latach 2006-2016 w Klinicznym Oddziale Chirurgii Czaszkowo-Szczękowo-Twarzowej Wojskowego Instytutu Medycznego w Warszawie z powodu nowotworów ślinianek przyusznych hospitalizowano i leczono 149 pacjentów.
View Article and Find Full Text PDFAim Of The Study: Presents our experience in reconstruction of postsurgical defects with use of temporal muscle flap.
Material And Methods: In the years 1996-2010 we treated 10 patients with malignant neoplasms of maxillo-facial region. Following tumor removal the fascia-muscle flaps of temporal muscle were used for reconstruction.
Development of vascular and systemic calcification is one of the more serious and often occurring complications in hemodialyzed patients. The cardiac valves calcifications are of the essential importance. They are result of the very complicated calcification process connected with hyperphosphataemia, hyperparathyroidism, calcium carbonate administering and active vitamin D3 metabolites as well as using dialysis fluids with high concentration of calcium.
View Article and Find Full Text PDFBackground: The study was undertaken to establish the pharmacological basis of the stimulatory activity of galantide (M15) and galanin(1-14)-(a-aminobutyric acid8-[Abu8])scyliorhinin-I [Scy-I] in gastric smooth muscle.
Material/methods: Isotonic contractions of the isolated, longitudinal rat gastric fundus strips were recorded.
Results: Galanin, galanin(1-15)-NH2, M15 and galanin(1-14)-[Abu8]Scy-I elicited concentration-dependent contractions.