Articles de revues : « Lithic substrate »

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Casero, María Cristina, Victoria Meslier, Jocelyne DiRuggiero, Antonio Quesada, Carmen Ascaso, Octavio Artieda, Tomasz Kowaluk et Jacek Wierzchos. « The composition of endolithic communities in gypcrete is determined by the specific microhabitat architecture ». Biogeosciences 18, n^o 3 (10 février 2021) : 993–1007. http://dx.doi.org/10.5194/bg-18-993-2021.

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Abstract. Endolithic microhabitats have been described as the last refuge for life in arid and hyper-arid deserts where life has to deal with harsh environmental conditions. A number of rock substrates from the hyper-arid Atacama Desert, colonized by endolithic microbial communities such as halite, gypsum crusts, gypcrete, calcite, granite and ignimbrite, have been characterized and compared using different approaches. In this work, three different endolithic microhabitats are described, each one with a particular origin and architecture, found within a lithic substrate known as gypcrete. Gypcrete, an evaporitic rock mainly composed of gypsum (CaSO4 ⋅ 2H2O) and collected in the Cordón de Lila area of the desert (Preandean Atacama Desert), was found to harbour cryptoendolithic (within pore spaces in the rock), chasmoendolithic (within cracks and fissures) and hypoendolithic (within microcave-like pores in the bottom layer of rock) microhabitats. A combination of microscopy investigation and high-throughput sequencing approaches were used to characterize the endolithic communities and their habitats at the microscale within the same piece of gypcrete. Microscopy techniques revealed differences in the architecture of the endolithic microhabitats and the distribution of the microorganisms within those microhabitats. Cyanobacteria and Proteobacteria were dominant in the endolithic communities, of which the hypoendolithic community was the least diverse and hosted unique taxa, as a result of less access to sun radiation. These results show, for the first time, that the differences in the architecture of a microhabitat, even within the same piece of a lithic substrate, play an essential role in shaping the diversity and composition of endolithic microbial communities.

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McBrearty, Sally, Laura Bishop, Thomas Plummer, Robert Dewar et Nicholas Conard. « Tools Underfoot : Human Trampling as an Agent of Lithic Artifact Edge Modification ». American Antiquity 63, n^o 1 (janvier 1998) : 108–29. http://dx.doi.org/10.2307/2694779.

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A series of eight replication experiments tests the proposition that human trampling of stone flakes can produce edge damage that mimics deliberate retouch. Retouchlike edge damage, breakage, and other forms of macroscopic mechanical damage were observed on large numbers of pieces in all trampled sets. Experiments measured the relative contributions of three variables-raw material, artifact density, and substrate-in generating damage. Results indicate that while all three factors contribute to some degree, substrate plays the most decisive role, and that artifacts are more likely to exhibit damage if trampled on an impenetrable substrate. It was further found that trampling transforms flakes into pseudo-tools that can be classified as formal tools using a standard typology. Many of these are notched and denticulate pieces, indicating that special caution is needed in behavioral interpretations based on these tool types, and that the European Paleolithic Denticulate Mousterian industry requires critical reassessment.

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Shipway, J. Reuben, Marvin A. Altamia, Gary Rosenberg, Gisela P. Concepcion, Margo G. Haygood et Daniel L. Distel. « A rock-boring and rock-ingesting freshwater bivalve (shipworm) from the Philippines ». Proceedings of the Royal Society B : Biological Sciences 286, n^o 1905 (19 juin 2019) : 20190434. http://dx.doi.org/10.1098/rspb.2019.0434.

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Shipworms are a group of wood-boring and wood-feeding bivalves of extraordinary economic, ecological and historical importance. Known in the literature since the fourth century BC, shipworms are both destructive pests and critical providers of ecosystem services. All previously described shipworms are obligate wood-borers, completing all or part of their life cycle in wood and most are thought to use wood as a primary source of nutrition. Here, we report and describe a new anatomically and morphologically divergent species of shipworm that bores in carbonate limestone rather than in woody substrates and lacks adaptations associated with wood-boring and wood digestion. The species is highly unusual in that it bores by ingesting rock and is among the very few known freshwater rock-boring macrobioeroders. The calcareous burrow linings of this species resemble fossil borings normally associated with bivalve bioerosion of wood substrates (ichnospecies Teredolites longissimus ) in marginal and fully marine settings. The occurrence of this newly recognized shipworm in a lithic substrate has implications for teredinid phylogeny and evolution, and interpreting palaeoenvironmental conditions based on fossil bioerosion features.

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Roche, Olivier. « Nature and velocity of pyroclastic density currents inferred from models of entrainment of substrate lithic clasts ». Earth and Planetary Science Letters 418 (mai 2015) : 115–25. http://dx.doi.org/10.1016/j.epsl.2015.03.001.

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Gifford-Gonzalez, Diane P., David B. Damrosch, Debra R. Damrosch, John Pryor et Robert L. Thunen. « The Third Dimension in Site Structure : An Experiment in Trampling and Vertical Dispersal ». American Antiquity 50, n^o 4 (octobre 1985) : 803–18. http://dx.doi.org/10.2307/280169.

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AbstractTwo measured and weighed assemblages of lithic debitage were subjected to human treadage, one set on a compact sandy silt (“loam”) substrate, the other on unconsolidated sand. The assemblages were excavated, plotted in three dimensions, and documented for damage. Downward migration of pieces at the loam site was minimal: fracture of small pieces was the dominant damage pattern. Most sand site pieces migrated to 3-8 cm depth; vertical distribution of pieces approximated a normal curve, and edge-damage to larger pieces was the dominant damage pattern. Vertical distribution of artifacts at the sand site approximated a pattern observed in two other trampling experiments and a number of archaeological occurrences. Factors influencing these distributions are discussed.

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Smith, Ru D. A., et Andrew J. Ross. « Amberground pholadid bivalve borings and inclusions in Burmese amber : implications for proximity of resin-producing forests to brackish waters, and the age of the amber ». Earth and Environmental Science Transactions of the Royal Society of Edinburgh 107, n^o 2-3 (juin 2016) : 239–47. http://dx.doi.org/10.1017/s1755691017000287.

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ABSTRACTClavate (club-shaped) structures rimming mid-Cretaceous Burmese amber from Myanmar, previously misdiagnosed as fungal sporocarps, are shown to be domichnia (crypts) of martesiine bivalves (Pholadidae: Martesiinae). They are similar in form to Teredolites clavatus Leymerie, 1842 and Gastrochaenolites lapidicus Kelly & Bromley, 1984; however, the former identification is preferable, given that they are martesiine crypts in amber as opposed to a lithic substrate. Cross-cutting relationships between the clavate features and inclusions in the amber demonstrate that the features post-date hardening of the resin. The fills of the crypts are variable, including sand grade sediment of very fine to coarse sand grainsize, and sparry calcite cements. In some cases, the articulated valves of the pholadid bivalve responsible are visible inside the borings. However, one remarkable specimen contains two pairs of articulated shells ‘floating’ in amber, not associated with crypts; an observation that suggests that the resin was still liquid or soft when the bivalves were trapped in the resin. One individual is associated with an irregular sediment-filled feature and shows shell breakage. Formation of a solid rim around a liquid central volume has been documented in subaqueous bodies of resin in modern swamp forests, and argues for a close proximity between the amber-producing trees and a brackish water habitat for the bivalves. The presence of pyrite as thin films and crystal groups within Burmese amber is further consistent with such a depositional environment. Comparison of the size of pholadid body fossils with growth rates of modern equivalents allows the duration of boring activities to be estimated and suggests that small fossil pholadids in Burmese amber became trapped and died within 1–2 weeks of having settled on the resin. Larger examples present within well-formed domichnia formed in hardened resin. Since ‘hardground’ describes early lithified sediment as a substrate and ‘woodground’ describes wood as a substrate, the term ‘amberground’ is used here to described borings in an amber substrate.

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Koski, Randolph A. « Ferromanganese deposits from the Gulf of Alaska Seamount Province : mineralogy, chemistry, and origin ». Canadian Journal of Earth Sciences 25, n^o 1 (1 janvier 1988) : 116–33. http://dx.doi.org/10.1139/e88-012.

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Ferromanganese-oxide deposits dredged from four seamounts (Welker, Miller, Murray, and Patton) in the Gulf of Alaska Seamount Province include poorly crystallized microlaminated crusts on basalt substrate, well-crystallized Mn-oxide veins in epiclastic sedimentary rocks, and crystalline Mn-oxide layers and micronodules in phosphorite. The principal rock types dredged are alkali-basalt pillow fragments and tuffaceous conglomerate and sandstone. The glassy rims of pillow fragments, the glassy goundmass of large volcanic clasts, and the tuffaceous component of the sediment are altered to palagonite. Other low-temperature alteration products include phillipsite, smectite, and carbonate-apatite.Thick (10–50 mm) Fe–Mn crusts consist mainly of δ-MnO2; straight and cuspate growth laminae indicate variable growth rates and periods of nondeposition. A larger number of detrital particles toward the top of thick crusts record the increasing influence of active volcanoes of the Aleutian arc during northwestward movement of the Pacific plate. Thick crusts on basalt substrate have higher Mn/Fe ratios and lower Co content than Fe–Mn crusts from low-latitude seamounts of the central Pacific region. Thin (< 10 mm) crusts on volcaniclastic substrate contain todorokite and birnessite and have higher Mn/Fe ratios, Ni, and Cu and lower Fe and Co than thick Gulf of Alaska crusts.Veins of todorokite and cryptomelane with complex internal structure occur in altered tuffaceous sandstone and conglomerate from Miller Seamount. Fibrous todorokite has a composition similar to those of other marine examples but may contain up to 7% Mn2+ in M2 sites. Microprobe analysis of the marine cryptomelane indicates a composition that is approximately (K,Ba)1–2(Mn4+,Co)7–8O16∙x(H2O).A third type of Fe–Mn deposit in phosphorite is an intimate mixture of todorokite (and minor δ-MnO2)-bearing layers and micronodules, carbonate-apatite, and phillipsite that encloses grains of altered volcanic glass and lithic fragments.The microlaminated structure, mineralogy (predominantly δ-MnO2), and composition (Mn/Fe ratio and transition metal, rare earth element, U, and Th contents) of the thick crusts are characteristic of hydrogenetic Fe–Mn crusts elsewhere in the Pacific. Conversely, the crystallinity and chemical composition of the Mn-oxide veins and thin crusts indicate formation during diagenesis of the volcanogenic sediment substrate. Mn and other transition metals are mobilized during low-temperature oxidative alteration (palagonitization) of basaltic volcanic glass; the oxidation of Fe2+ to Fe3+ during palagonitization and the dissolution of the dilute biogenic fraction of the sediment combine to lower the Eh of ambient pore fluid and enhance the mobility of Mn2+. Diagenesis in the phosphatic sandstone from Patton Seamount involves organic-rich sediment and pore waters elevated in phosphorus owing to upwelling above a large volcanic edifice.

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McPherron, Shannon P., David R. Braun, Tamara Dogandžić, Will Archer, Dawit Desta et Sam C. Lin. « An experimental assessment of the influences on edge damage to lithic artifacts : a consideration of edge angle, substrate grain size, raw material properties, and exposed face ». Journal of Archaeological Science 49 (septembre 2014) : 70–82. http://dx.doi.org/10.1016/j.jas.2014.04.003.

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Anderson, Dennis S., et Ronald B. Davis. « The vegetation and its environments in Maine peatlands ». Canadian Journal of Botany 75, n^o 10 (1 octobre 1997) : 1785–805. http://dx.doi.org/10.1139/b97-893.

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This study is based on relevés from 96 peatlands representing the typologic, environmental, and geographic variation of Maine peatlands, and on peat pore-water chemistry at a representative set of 51 of these peatlands. We give optima and tolerances of pH, Ca, P, NO3-N, NH4-N, and influence of upper on lower vegetational strata for the 73 most common vascular plant species, excluding sedges, which are presented elsewhere. The program TWINSPAN differentiated 30 plant communities. Environments of the first seven TWINSPAN divisions differed largely by Ca, pH, P, NH4, Fe, microrelief, substrate depth, degree of humification, and climate. A canonical correspondence analysis (CCA) with forward selection entered pH, P, Na, Fe, Ca, Mg, and percent H2O as the minimum number of variables which best explains species variation. A CCA of the lower strata vascular plants demonstrated the importance of the upper strata (percent overstory) on species' distributions. Gradients of pH–alkalinity and percent overstory are primary in determining Maine's peatland vegetation. Other important gradients are percent H2O in upper peat, concentrations of lithic elements (P, Fe, Mn, Al, and Si) in pore water, and climate. Although these gradients partially covary, some of the variation in species' distributions can be attributed to independent aspects of individual gradients. Species richness across the range of peatland types is related to pH–alkalinity for vascular plants, and to percent H2O, microrelief, and percent overstory for bryophytes. Key words: plant communities, Maine, multivariate statistical analysis, peatlands, mires, vegetation.

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Wu, Yue, Cheng Wang, Zewen Yang, Depeng Song, Takeo Ohsaka, Futoshi Matsumoto, Xiaolin Sun et Jianfei Wu. « Designing conductive networks of hybrid carbon enables stable and long-lifespan cotton-fiber-based lithium–sulfur batteries ». RSC Advances 11, n^o 55 (2021) : 34955–62. http://dx.doi.org/10.1039/d1ra06568h.

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Katsui, Hirokazu, Yamashita Yuji et Takashi Goto. « Orientation and Morphology of LiCoO₂ Prepared by Chemical Vapor Deposition on Al₂O₃ Single Crystal ». Key Engineering Materials 508 (mars 2012) : 300–303. http://dx.doi.org/10.4028/www.scientific.net/kem.508.300.

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Lithium Cobaltate (LiCoO2) Films Were Prepared on the (001), (110), (110) and (112) Planes of Al2O3 Single Crystals Substrates by Metal Organic Chemical Vapor Deposition, and the Phases, Orientated Textures and Surface Morphologies Were Examined. (001)-Oriented LiCoO2 Films Were Obtained on (001) and (110) Al2O3 Substrates, while (018)- and (104)-Oriented LiCoO2 Films Were Grown on (110) and (112) Al2O3 Substrate. Triangular and Elongated Rectangular Faceted Structures Were Directionally Aligned, and (001)- and (018)-Oriented Grains Were Epitaxially Grown on (001) and (110) Al2O3 Substrates. Randomly Arranged Polygonal Faceted Structures Were Observed in the (001)-Oriented Licoo2 Film on (110) Al2O3 Substrate, while Locally Inhomogeneous Grains Were Observed in the (104)-Oriented LiCoO2 Film on (1_,12) Al2O3 Substrate.

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Lochmann, Lubomír, et Miroslav Janata. « 50 years of superbases made from organolithium compounds and heavier alkali metal alkoxides ». Open Chemistry 12, n^o 5 (1 mai 2014) : 537–48. http://dx.doi.org/10.2478/s11532-014-0528-0.

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AbstractA review of reactions of organolithium compounds (RLi) with alkali metal alkoxides is presented. On the one hand, simple lithium alkoxides form adducts with RLi the reactivity of which differs only slightly from that of RLi. On the other hand, after mixing heavier alkali metal alkoxides (R’OM, M = Na, K, Rb, Cs) with RLi, a new system is formed, which has reactivity that dramatically exceeds that of the parent RLi. A metal interchange, according to the equation RLi + R’OM = RM + R’OLi, occurs in this system, giving rise to a superbase. This reaction is frequently used for the preparation of heavier alkali metal organometallic compounds. Similar metal interchange takes place between R’OM and compounds such as lithium amides and lithium enolates of ketones or esters, thus demonstrating the general nature of this procedure. Superbases react easily with many types of organic compounds (substrates), resulting in the formation of a heavier alkali metal derivative of the substrate (metalation). The metalated substrate can react in situ with an electrophile to yield the substituted substrate, a procedure that is frequently used in synthetic and polymer chemistry. An improved mechanism of metal interchange and reaction of superbases with substrates is proposed.

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Mavrin, Aleksey A., et Andrey A. Pshenov. « Tolerable Stationary Heat Loads to Liquid Lithium Divertor Targets ». Plasma 5, n^o 4 (15 novembre 2022) : 482–98. http://dx.doi.org/10.3390/plasma5040036.

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An 0D model is proposed that makes it possible to estimate the limiting stationary heat loads to the targets covered with liquid lithium (LL) layer, taking into account the effects of vapor shielding by sputtered and evaporated LL and hydrogen recycling. Several models of cooled target substrates are considered in which the LL layer facing the plasma is placed. For the considered substrate models, a parametric analysis of the tolerable stationary heat loads to the target on the substrate thickness, the effective cooling energy per particle of sputtered lithium, and the lithium prompt redeposition factor was carried out. It is shown that, at a small substrate thickness, the choice of the substrate model has a significant impact on the tolerable heat loads. It is also shown that even at unrealistically large values of the effective cooling energy, the dissipation of lithium remains modest. This means that in regimes with a high power coming from the core plasma to the edge, the injection of an additional radiator is required. Finally, it is shown that one of the most effective ways to increase the tolerable stationary heat loads would be to reduce the thickness of the target substrate.

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Tsujimoto, A., WW Barkmeier, T. Takamizawa, TM Wilwerding, MA Latta et M. Miyazaki. « Interfacial Characteristics and Bond Durability of Universal Adhesive to Various Substrates ». Operative Dentistry 42, n^o 2 (1 mars 2017) : E59—E70. http://dx.doi.org/10.2341/15-353-l.

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SUMMARY Objective: This study investigated the interfacial characteristics and bond durability of universal adhesives to various substrates. Methods and Materials: Two universal adhesives were used: 1) Scotchbond Universal and 2) G-Premio Bond. The substrates used were bovine enamel and dentin with or without phosphoric acid etching, resin composite, lithium disilicate and leucite-reinforced glass ceramics, zirconia, and metal alloys. The surface free energy and the parameters of various substrates and of substrates treated by adhesive after light irradiation were determined by measuring the contact angles of three test liquids. Resin composite was bonded to the various substrates to determine shear bond strength after 24 hours water storage and 10,000 thermal cycles. A one-way analysis of variance (ANOVA) and the Tukey post hoc test were used for the surface free energy data, and a two-way ANOVA and the Tukey post hoc test were used for analysis of shear bond strength data (α=0.05). Results: The interfacial characteristics of the various substrates show significant differences depending on the type of substrate, but the interfacial characteristics of substrate treated by adhesive after light irradiation did not show any significant differences regardless of the substrate used. The bond durability of two universal adhesives to various substrates differs depending on the type of substrate and the adhesive. Conclusions: The results of this study suggest that universal adhesives modify the interfacial characteristics of a wide range of substrates and create a consistent surface, but the bond durability of universal adhesive to various substrates differs depending on the type of substrate and the adhesive.

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Kim, Hakkwan, et Alexander H. King. « Control of porosity in fluoride thin films prepared by vapor deposition ». Journal of Materials Research 22, n^o 7 (juillet 2007) : 2012–16. http://dx.doi.org/10.1557/jmr.2007.0225.

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We have measured the porosity in thin films of lithium fluoride (LiF), magnesium fluoride (MgF2), barium fluoride (BaF2), and calcium fluoride (CaF2) as a function of the substrate temperature for films deposited by thermal evaporation onto glass substrates. The amount of porosity in the thin films was measured using an atomic force microscope and a quartz crystal thickness monitor. The porosity was very sensitive to the substrate temperature and decreased as the substrate temperature increased. Consistent behavior was observed among all of the materials in this study.

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Kikkawa, S., M. Miyazaki et M. Koizumi. « Titanium disulfide thin film prepared by plasma CVD ». Journal of Materials Research 5, n^o 12 (décembre 1990) : 2894–901. http://dx.doi.org/10.1557/jmr.1990.2894.

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Titanium disulfide films were prepared by plasma CVD. Crystalline orientation of layered TiS2 was investigated in relation to deposition rate, film thickness, and kinds of substrate. The preferred orientation of TiS2 basal plane perpendicular to substrates was obtained on the films with their thickness of more than ca. 10 μm at the deposition rate of ca. 4 ⊠ 10−3 g/cm2·h on all kinds of substrate. This orientation resulted in a large discharge capacity in a lithium battery cathode application.

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Souza, Jackson Mirellys Azevêdo, Sarita Leonel, Luis Lessi Dos Reis, Rafael Augusto Ferraz et Bruno Henrique Leite Gonçalves. « Biostimulant and substrates on litchi tree propagation by air layering ». Comunicata Scientiae 7, n^o 1 (10 mai 2016) : 122. http://dx.doi.org/10.14295/cs.v7i1.1383.

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The production of quality seedlings is important for the crop cycle and the main propagation type is by the air layering technique, which can be enhanced by using different substrates and plant growth regulators. Therefore, the objective of this study was to evaluate the use of a biostimulant and substrate types in the propagation of litchi tree by air layering. The experiment was installed in a commercial area in the city of Mogi Mirim, SP, Brazil and conducted in a randomized block design with a 5x2 factorial with four replications. The treatments consisted of five Stimulate® biostimulant concentrations (0, 3, 6, 9, and 12 ml L-1) and two substrate types (Plantmax® and earthworm humus). After 120 days, the root length (cm), number of roots, calloused and rooted layers percentage (%), root fresh and dry mass (g) and root volume (cm3) were evaluated. Based on the results, it was found that the concentrations of 6.1 and 6.9 ml L-1 promoted greater success in litchi tree propagation and that the layers can be produced on both evaluated substrates.

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Nurgazizov N. I., Bizyaev D. A., Bukharaev A. A., Chuklanov A. P., Shur V. Ya. et Akhmatkhanov A. R. « Influence of thermoinduced magnetoelastic effect on domain structure of planar Ni microparticles ». Physics of the Solid State 64, n^o 9 (2022) : 1305. http://dx.doi.org/10.21883/pss.2022.09.54171.29hh.

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Results of studying the domain structure of planar Ni microparticles formed on single-crystal substrates from the lithium niobate and from the potassium titanyl phosphate at different temperatures are presented. The dependence of domain sizes on the sample temperature was studied. It is shown the observed change of the domain structure is caused by the magnetoelastic effect, which arises due to the difference in the thermal expansion coefficients of the substrate and microparticles as the sample temperature changes. It is shown, the sizes of magnetic domains, up to the creation of a state with a quasi-homogeneous magnetization may be set by the substrate temperature during the microparticles formation. Keywords: magnetoelastic effect, magnetic force microscopy, remagnetization, lithium niobate, potassium titanyl phosphate, temperature.

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Jokerst, N. M. « Integrated Optoelectronics Using Thin Film Epitaxial Liftoff Materials and Devices ». Journal of Nonlinear Optical Physics & ; Materials 06, n^o 01 (mars 1997) : 19–48. http://dx.doi.org/10.1142/s0218863597000034.

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The separation of single crystal thin film epitaxial compound semiconductor layers from a lattice matched growth substrate through selective etching, with subsequent bonding of the epitaxial thin film devices onto host substrates, is an emerging tool for multi-material, hybrid integration. Progress to date in this area, presented herein, includes advanced thin film devices, thin film material separation and device integration processing techniques, and thin film material and device integration with host substrates which include silicon circuitry, polymers, glass, and lithium niobate.

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Lu, Yi, Benjamin Johnston, Peter Dekker, Michael J. Withford et Judith M. Dawes. « Channel Waveguides in Lithium Niobate and Lithium Tantalate ». Molecules 25, n^o 17 (27 août 2020) : 3925. http://dx.doi.org/10.3390/molecules25173925.

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Low-loss photonic waveguides in lithium niobate offer versatile functionality as nonlinear frequency converters, switches, and modulators for integrated optics. Combining the flexibility of laser processing with liquid phase epitaxy we have fabricated and characterized lithium niobate channel waveguides on lithium niobate and lithium tantalate. We used liquid phase epitaxy with K2O flux on laser-machined lithium niobate and lithium tantalate substrates. The laser-driven rapid-prototyping technique can be programmed to give machined features of various sizes, and liquid phase epitaxy produces high quality single-crystal, lithium niobate channels. The surface roughness of the lithium niobate channels on a lithium tantalate substrate was measured to be 90 nm. The lithium niobate channel waveguides exhibit propagation losses of 0.26 ± 0.04 dB/mm at a wavelength of 633 nm. Second harmonic generation at 980 nm was demonstrated using the channel waveguides, indicating that these waveguides retain their nonlinear optical properties.

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Prabhakar, Vidya, et Ashrit P. « Effect of substrate on the electro chromic properties of tungsten trioxide thin films ». International Journal of Engineering & ; Technology 3, n^o 2 (10 mai 2014) : 245. http://dx.doi.org/10.14419/ijet.v3i2.2084.

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Thin films of tungsten trioxide (WO3) were deposited onto glass and Indium Tin Oxide (ITO) coated glass substrates using thermal evaporation technique under various deposition conditions. In the present work the effect of substrate on the structure and EC performance of WO3 thin films has been examined using a dry lithiation method. The structural and optical changes occurring in these films with lithium insertion have been studied. It is found that the ITO coated substrate promotes the granulation and higher coloration efficiencies of the films. The peak efficiency is observed at higher infrared wavelengths where it is principally the reflectance modulation that brings about optical changes. Keywords: WO3 Thin Films, Electrochromism, Optical and Structural Properties, Effect of ITO Substrate.

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Dai, Z. R., Sangbeom Kang, W. Alan Doolittle, Z. L. Wang et April S. Brown. « Interfacial Structure and Defects in GaN/AlGaN Heterojunction Epitaxially Grown on LiGa02 Substrate by Molecular Beam Epitaxy ». Microscopy and Microanalysis 6, S2 (août 2000) : 1106–7. http://dx.doi.org/10.1017/s1431927600038022.

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The performance of III-Nitride based Light Emitting Diodes (LEDs), LASERs, GaN/AlGaN MODFETs (Modulation-doped Field Effect Transistors) and HEMTs (High Electron Mobility Transistors) have been improved dramatically over the past few years [1,2], despite the relatively poor material quality of GaN, as compared to GaAs, for example. The intrinsic properties of the materials system make it extremely well suited to both optoelectronic and microwave power transistor applications. Typically, GaN is grown on substrates such as GaAs, Al2O3 (sapphire) or SiC with large lattice mismatch. This has usually resulted in an extremely high defect density in the GaN layer. The growth of GaN on lithium gallate LiGaO2 (LGO) affords many advantages compared to all other available substrates. LGO offers the smallest average lattice mismatch of any available substrate for the Ill-nitrides. This facilitates the growth of high quality GaN directly on Lithium Gallate without the need for a defective buffer to decouple the strain associated with the large lattice mismatch of other substrates [3].

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Beaulieu, L. Y., A. D. Rutenberg et J. R. Dahn. « Measuring Thickness Changes in Thin Films Due to Chemical Reaction by Monitoring the Surface Roughness with In Situ Atomic Force Microscopy ». Microscopy and Microanalysis 8, n^o 5 (octobre 2002) : 422–28. http://dx.doi.org/10.1017/s1431927602010309.

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Measuring the changing thickness of a thin film, without a reference, using an atomic force microscope (AFM) is problematic. Here, we report a method for measuring film thickness based on in situ monitoring of surface roughness of films as their thickness changes. For example, in situ AFM roughness measurements have been performed on alloy film electrodes on rigid substrates as they react with lithium electrochemically. The addition (or removal) of lithium to (or from) the alloy causes the latter to expand (or contract) reversibly in the direction perpendicular to the substrate and, in principle, the change in the overall height of these materials is directly proportional to the change in roughness. If the substrate on which the film is deposited is not perfectly smooth, a correction to the direct proportionality is needed and this is also discussed.

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ONUKI, Teppei, Hirotaka OJIMA, Jun SHIMIZU, Libo ZHOU, Itaru TAKAHAMA et Kazuki KAMOSHIDA. « 1201 Machining quality controls in ultrashort pulse laser micromachining on lithium niobate substrates ». Proceedings of International Conference on Leading Edge Manufacturing in 21st century : LEM21 2015.8 (2015) : _1201–1_—_1201–4_. http://dx.doi.org/10.1299/jsmelem.2015.8._1201-1_.

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Нургазизов, Н. И., Д. А. Бизяев, А. А. Бухараев, А. П. Чукланов, В. Я. Шур et А. Р. Ахматханов. « Влияние термоиндуцированного магнитоупругого эффекта на доменную структуру планарных Ni-микрочастиц ». Физика твердого тела 64, n^o 9 (2022) : 1316. http://dx.doi.org/10.21883/ftt.2022.09.52826.29hh.

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Results of studying the domain structure of planar Ni microparticles formed on single-crystal substrates from the lithium niobate and from the potassium titanyl phosphate at different temperatures are presented. The dependence of domain sizes on the sample temperature was studied. It is shown the observed change of the domain structure is caused by the magnetoelastic effect, which arises due to the difference in the thermal expansion coefficients of the substrate and microparticles as the sample temperature changes. It is shown, the sizes of magnetic domains, up to the creation of a state with a quasi-homogeneous magnetization may be set by the substrate temperature during the microparticles formation.

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Morohashi, Rintarou, Naoki Wakiya, Takanori Kiguchi, Tomohiko Yoshioka, M. Tanaka et Kazuo Shinozaki. « Preparation of Epitaxial LiNbO₃ Thin Film by MOCVD and its Properties ». Key Engineering Materials 388 (septembre 2008) : 179–82. http://dx.doi.org/10.4028/www.scientific.net/kem.388.179.

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Lithium niobate (LiNbO3) thin films were deposited on Al2O3(001) substrates using metal-organic chemical vapor deposition (MOCVD), with Li(dpm) and Nb(C2H5)5 as precursors. By optimizing the conditions of thin film deposition, the c-axis oriented and epitaxially grown LiNbO3 thin films with stoichiometric composition were deposited on an Al2O3(001) substrate. The refractive index of the stoichiometric LiNbO3 thin film was 2.24 at = 632.8 nm, which is close to that of bulk crystal.

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Park, Tae Wan, Young Lim Kang, Sang Hyeon Lee, Gu Won No, Eun-Soo Park, Chan Park, Junghoon Lee et Woon Ik Park. « Formation of Li2CO3 Nanostructures for Lithium-Ion Battery Anode Application by Nanotransfer Printing ». Materials 14, n^o 7 (24 mars 2021) : 1585. http://dx.doi.org/10.3390/ma14071585.

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Various high-performance anode and cathode materials, such as lithium carbonate, lithium titanate, cobalt oxides, silicon, graphite, germanium, and tin, have been widely investigated in an effort to enhance the energy density storage properties of lithium-ion batteries (LIBs). However, the structural manipulation of anode materials to improve the battery performance remains a challenging issue. In LIBs, optimization of the anode material is a key technology affecting not only the power density but also the lifetime of the device. Here, we introduce a novel method by which to obtain nanostructures for LIB anode application on various surfaces via nanotransfer printing (nTP) process. We used a spark plasma sintering (SPS) process to fabricate a sputter target made of Li2CO3, which is used as an anode material for LIBs. Using the nTP process, various Li2CO3 nanoscale patterns, such as line, wave, and dot patterns on a SiO2/Si substrate, were successfully obtained. Furthermore, we show highly ordered Li2CO3 nanostructures on a variety of substrates, such as Al, Al2O3, flexible PET, and 2-Hydroxylethyl Methacrylate (HEMA) contact lens substrates. It is expected that the approach demonstrated here can provide new pathway to generate many other designable structures of various LIB anode materials.

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Tezcan, Tugba, Banu Sezer, Ugur Tamer et Ismail Hakki Boyaci. « Rapid and Reliable Detection of Lithium in Water Sources Using Surface Enhanced Laser Induced Breakdown Spectroscopy (SENLIBS) on Aluminium Substrate ». International Journal of Engineering and Technology 15, n^o 1 (février 2023) : 17–21. http://dx.doi.org/10.7763/ijet.2023.v15.1212.

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Lithium is one of the most important materials in re-chargeable battery as well as pharmaceutical and automotive industry. Due to the increasing demand for lithium for industrial production and daily usage, the reliable detection and recovery of lithium, a non-renewable metal, from water resources is an essential requirement. In this work, we performed lithium detection using surface enhanced laser induced breakdown spectroscopy on aluminium (Al) substrate for three different matrices, sea, river and municipal water. We also examined the matrix effect on sensitivity of lithium detection. Lithium spiked samples in different concentration (0- 100 ppm) was dried on an Al surface. The specific emission line of Li 670 nm was used for quantitative analysis. The intensity of Li was obtained about 15 times on Al substrate better than microscope glass. The limit of detection (LOD) value achieved to 0.138 ppm. No significant matrix effect was observed in the different water sources. Good reliability was obtained for intra and inter-day precision methods with RSD is <3.7% and<7.3% respectively in all water samples. Total analysis time including sample preparation is approximately in 1 min. We demonstrated that SENLIBS method provides rapid, high accuracy and repeatability of sensitive Li detection in different water sources.

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Liu, Xunxian, Xinyue Lu, Kaimei Song et Marc R. Blackman. « Natural Functions of PLIN2 Mediating Wnt/LiCl Signaling and Glycogen Synthase Kinase 3 (GSK3)/GSK3 Substrate-Related Effects Are Modulated by Lipid ». Molecular and Cellular Biology 36, n^o 3 (23 novembre 2015) : 421–37. http://dx.doi.org/10.1128/mcb.00510-15.

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Belonging to the PLIN family, PLIN2 associates with lipid storage droplets (LSDs), but other functions of PLIN2 remain unclear. Here, we suggest that PLIN2 mediates Wnt signaling because PLIN2 small interfering RNA (siRNA) suppresses activation of Wnt/coreceptor pathways. The mediation in the Wnt/Frizzled pathway seems to occur from Dishevelleds to axin/glycogen synthase kinase 3(GSK3)/β-catenin complexes (AGβC) as Wnt decreases Dishevelled/PLIN2 but increases AGβC/PLIN2 associations. Augmenting cellular LSDs that affect PLIN2 associations with these proteins, oleic acid (OA) treatment inhibits Wnt-increased AGβC/PLIN2 associations and β-catenin T-cell factor signaling (β-CTS). Revealing that PLIN2 is a GSK3-associated protein, the study explored PLIN2-mediated effects on GSK3/GSK3 substrates. PLIN2 siRNA reduces inhibitory GSK3 levels and lithium chloride (LiCl)-upregulated β-catenin or CCAAT/enhancer binding protein α (c/EBPα) expression. OA treatment decreases LiCl-increased c/EBPα via PLIN2-c/EBPα dissociation. In addition to PLIN2 overexpression increasing β-CTS, PLIN2 depletion or overexpression drops or adds expression of GSK3 substrates, such as β-catenin, c/EBPα,c-Myc, cyclin D1, and insulin receptor substrate 1, and cell growth/survival. PLIN2 N or C terminus overexpression that is associated with higher levels of the substrates suggests that those substrates bind to specific regions of PLIN2. Mimicking the possible high lipid concentrations in cells in the human body under conditions of hyperlipidemia/obesity, OA-treated cells gain or reduce GSK3 substrate expression in parallel with a decrease (a Wnt-like effect) or increase in GSK3 activity, likely regulated by GSK3/PLIN2/GSK3 substrate associations.

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Рыжкова, М. В., Е. А. Борисенко, М. В. Иванченко, Д. А. Цуканов, А. В. Зотов et А. А. Саранин. « Исследование поверхностной проводимости двойного слоя таллия на Si(111) после адсорбции лития и рубидия ». Письма в журнал технической физики 44, n^o 10 (2018) : 12. http://dx.doi.org/10.21883/pjtf.2018.10.46094.17220.

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AbstractChanges in the state of a thallium bilayer on Si(111) substrate, Si(111)6 × 6–Tl, after adsorption of lithium and rubidium were studied using low-energy electron-diffraction and four-point probe-conductivity measurements. New surface reconstructions 5 × 1 and $$5\sqrt 3 \times 5\sqrt 3 $$ 5 3 × 5 3 were observed after the adsorption of lithium, and 2 × 2 and $$\sqrt 3 \times \sqrt 3 $$ 3 × 3 reconstructions appeared after the adsorption of rubidium. The surface conductivity of silicon substrates was studied as a function of the dose of deposited adsorbate. It is established that the formation of both 5 × 1 and 2 × 2 reconstructions retains the conducting properties of a two-dimensional channel constituted by the thallium bilayer.

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Madhuri, K. V., et M. Bujji Babu. « Morphological, optical and electrochromic properties of dry-lithiated nanostructured WO3 thin films ». Materials Science-Poland 36, n^o 2 (25 juin 2018) : 341–47. http://dx.doi.org/10.2478/msp-2018-0048.

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Abstract Tungsten trioxide (WO3) thin films were prepared by thermal evaporation technique on thoroughly cleaned glass substrates at high pressure of 133.322 mPa in presence of argon. The substrate temperature was maintained from 6 °C to 8 °C with the help of a cold jar. The deposited films were annealed at 400 °C in air for about 2 hours. The films were characterized in terms of their composition by X-ray photoelectron spectroscopy. Subsequently, the laboratory developed dry lithiation method was used to intercalate lithium atoms into as-deposited films in various proportions. With the amount of lithium content inserted into the film, the films showed coloration in visible and near infrared regions. The morphology, coloration efficiency and optical constants of annealed and lithiated films were calculated.

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Doolittle, William A. « Growth of GaN on lithium gallate substrates for development of a GaN thin compliant substrate ». Journal of Vacuum Science & ; Technology B : Microelectronics and Nanometer Structures 16, n^o 3 (mai 1998) : 1300. http://dx.doi.org/10.1116/1.590005.

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Kisailus, David, et F. F. Lange. « Growth of epitaxial GaN on LiGaO2 substrates via a reaction with ammonia ». Journal of Materials Research 16, n^o 7 (juillet 2001) : 2077–81. http://dx.doi.org/10.1557/jmr.2001.0284.

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Oriented GaN and LixGa(2−x)O2xN2(1−x) thin films were found to grow on LiGaO2 single-crystal (001) substrates via a reaction between ammonia (or reactive ammonia species) and substrate components at temperatures between 700 and 1000 °C. The compound LixGa(2−x)O2xN2(1−x), where x was determined to be ≈0.35, is a solid solution formed from a partial reaction of ammonia with the LiGaO2 substrate. Negligible lithium (i.e., x ≈ ≈ 0) was detected in the films formed with a constant high flow rate (164 cm3/min) of ammonia, indicating a complete reaction with the LiGaO2 single crystal. The growth of a partial surface film and surface pitting suggests a vapor reaction (via loss of LiNH2 or LiOH, and nitridation of Ga2O) similar to that observed when semiconductor grade reacts with N2 to form Si3N4. The resultant films have either a wurtzite structure or one approaching the wurtzite structure. Both films form on the substrate with the same orientation as the LiGaO2.

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Tsukanov D. A. et Ryzhkova M. V. « Study of structural and electrical properties of the reconstructed Si(111) surface after lithium adsorption ». Technical Physics 92, n^o 8 (2022) : 1040. http://dx.doi.org/10.21883/tp.2022.08.54570.83-22.

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The results of a study of the crystal structure and surface conductivity of a Si(111) silicon substrate with a reconstructed surface after deposition of submonolayer doses of lithium are presented. We used the method of low energy electron diffraction to study changes in the structure of the crystal lattice of the surface, as well as the four-point probe method for measuring the conductivity of substrates under in situ conditions. As the initial surfaces, we used the Si(111)7x7 reconstruction of an atomically clean silicon substrate, and the reconstructions obtained by adsorption of 1 ML of gold, lead, and bismuth atoms: Si(111)β-3x3-Au, Si(111)1x1-Pb and Si(111)β-3x3-Bi, respectively. Keywords: silicon surface, adsorption, surface reconstruction, surface conductivity, low-energy electron diffraction.

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Maño, Encarna Piquer, Rafael Marco Algarra, Amr Fawzy, Vicente C. B. Leitune, Fabrício M. Collares, Victor Feitosa et Salvatore Sauro. « In Vitro Bonding Performance of Modern Self-Adhesive Resin Cements and Conventional Resin-Modified Glass Ionomer Cements to Prosthetic Substrates ». Applied Sciences 10, n^o 22 (18 novembre 2020) : 8157. http://dx.doi.org/10.3390/app10228157.

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This study aimed at evaluating the shear bond strength (SBS) of modern self-adhesive resin cements and resin-modified glass ionomer cements applied to different prosthetic substrates. Zirconia, lithium-disilicate glass-ceramic and a noble metal alloy were used as bonding substrates. They were all sand-blasted with alumina, while LD was further etched with 9.6% hydrofluoric acid (10 s). A light-curing resin-modified glass ionomer cement (3M-GIC: Ketac Cem Plus) and a self-curing resin-modified glass ionomer cement (GC-GIC: FujiCEM 2) were compared to self-adhesive resin cements (PAN: Panavia SA Universal) and (3M-RES: Rely X Unicem 2). Ten specimens for each substrate were produced and up to five cylinders of each cement were bonded to each substrate. The shear bond strength (SBS) was evaluated after 24 h or after thermocycling (TC) aging (5000 cycles). The data was statistically analysed by two-way ANOVA and Student–Newman–Keuls test (α = 0.05). Failure modes were analysed through stereoscopic microscopy. The greatest SBS was attained with PAN, whilst 3M-GIC showed the lowest SBS and failed prevalently in adhesive mode. No difference in SBS was observed between GC-GIC and 3M-RES. After TC aging, all cements showed significant drop (p < 0.05) in SBS, but PAN showed the greatest SBS. Reliable bond strength to prosthetic substrates can be achieved with specific universal resin-luting cements and may be an alternative to glass ionomer cements when luting alloy substrates.

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Oshiro, Naomi, et Ana M. Pajor. « Functional characterization of high-affinity Na+/dicarboxylate cotransporter found in Xenopus laevis kidney and heart ». American Journal of Physiology-Cell Physiology 289, n^o 5 (novembre 2005) : C1159—C1168. http://dx.doi.org/10.1152/ajpcell.00295.2004.

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The SLC13 gene family includes sodium-coupled transporters for citric acid cycle intermediates and sulfate. The present study describes the sequence and functional characterization of a SLC13 family member from Xenopus laevis, the high-affinity Na+/dicarboxylate cotransporter xNaDC-3. The cDNA sequence of xNaDC-3 codes for a protein of 602 amino acids that is ∼70% identical to the sequences of mammalian NaDC-3 orthologs. The message for xNaDC-3 is found in the kidney, liver, intestine, and heart. The xNaDC-3 has a high affinity for substrate, including a Km for succinate of 4 μM, and it is inhibited by the NaDC-3 test substrates 2,3-dimethylsuccinate and adipate. The transport of succinate by xNaDC-3 is dependent on sodium, with sigmoidal activation kinetics, and lithium can partially substitute for sodium. As with other members of the family, xNaDC-3 is electrogenic and exhibits inward substrate-dependent currents in the presence of sodium. However, other electrophysiological properties of xNaDC-3 are unique and involve large leak currents, possibly mediated by anions, that are activated by binding of sodium or lithium to a single site.

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Si, Mengting, Chengli Wang, Can Yang, Wei Peng, Lixing You, Zhongxu Li, Hui Zhang et al. « Superconducting NbN thin films on various (X/Y/Z-cut) lithium niobate substrates ». Superconductor Science and Technology 35, n^o 2 (31 décembre 2021) : 025012. http://dx.doi.org/10.1088/1361-6668/ac459e.

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Abstract Lithium niobate (LN) exhibits outstanding properties in various application of photonics, electronics, and optoelectronics, showing potentials in integration. Due to the directional dependence of LN tensor properties, optical elements made up by LN favor the type of LN substrate. To introduce high-performance superconducting nanowire single-photon detectors (SNSPDs) to LN-integrated photonics chips, superconducting NbN thin films with thicknesses from 3 to 50 nm were deposited on X-cut, Y-cut, and Z-cut LN substrates using magnetron sputtering at room temperature. The different thickness dependencies of T c, δT c, and residual resistance ratios are observed in NbN thin films on different LN substrates. NbN thin films on X-cut and Y-cut LN substrates are polycrystalline with a transition temperature (T c) of ∼6 K for a 6 nm thick film. While NbN thin films are epitaxially textured on Z-cut LN substrates with T c of 11.5 K for a 6 nm thick film. NbN-SNSPD on X-cut LN substrates shows a weak saturation trend of its system detection efficiency; however, the performance of NbN-SNSPD on Z-cut LN substrates is limited. We evaluated the selection of cuts and concluded that X-cut and Y-cut LN are more suitable to be a platform of integrated LN photonic chips from the aspect of NbN-SNSPD. This study helps fabricate high-performance SNSPDs on fully integrated photonics chips on LN substrates.

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Kim, Hyoun Woo, Jong Woo Lee, Jeong Whan Han, Hyung Sun Kim, Mok Soon Kim, Byung Don Yoo et Sun Keun Hwang. « Growth of In₂O₃ Thin Films on Lithium Aluminum Oxide Using a Triethylindium and Oxygen Mixture ». Key Engineering Materials 342-343 (juillet 2007) : 625–28. http://dx.doi.org/10.4028/www.scientific.net/kem.342-343.625.

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Indium oxide (In2O3) films were successfully grown on LiAlO2 substrates using the triethylindium (TEI) as a precursor in the presence of oxygen in the metalorganic chemical vapor deposition process. We have established the correlation between the substrate temperature and the structural properties. The grain structures were clearly shown on the surface of the films deposited at 350°C. The root mean square (RMS) surface roughness of the In2O3 films increased with increasing the substrate temperature. A photoluminescence measurement at room temperature exhibited a yellow-green emission band centered at 585 nm.

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Mhatre, Sveeta V., Amita A. Bhagit et Raman P. Yadav. « Proteinaceous Pancreatic Lipase Inhibitor from the Seed of Litchi chinensis ». Food technology and biotechnology 57, n^o 1 (2019) : 113–18. http://dx.doi.org/10.17113/ftb.57.01.19.5909.

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A study of the pancreatic lipase inhibitory activity of a protein from the seed of Litchi chinensis was carried out. Protein was isolated by 70 % ammonium sulphate precipitation followed by dialysis. Lipase inhibitory activity of the protein was evaluated using both synthetic (p-nitrophenyl palmitate) and natural (olive oil) substrates. Protein at the final concentration of 100 µg/mL was able to inhibit 68.2 % pancreatic lipase on synthetic substrate and 60.0 % on natural substrate. Proteinaceous nature of the inhibitor was determined using trypsinization assay. Pancreatic lipase inhibitory protein was sensitive to 0.05 % trypsin treatment with the loss of 61.9 % activity. IC50 of this proteinaceous pancreatic lipase inhibitor was 73.1 µg/mL using synthetic substrate. This inhibitory protein was sensitive to pH, with the highest inhibitory activity at pH=8.0 and the lowest at pH=3.0. Protein was further analyzed using 10 % non-reducing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and, interestingly, it showed the presence of a single band of (61±2) kDa when stained with Coomassie brilliant blue. The isolated protein was finally crystallized to see its homogeneity by batch crystallization method. Crystals were well formed with distinct edges. The isolated protein showed good pancreatic lipase inhibitory activity.

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Al-Zordk, Walid, Alaa Saudi, Abdelraheem Abdelkader, Mansoura Taher et Mohamed Ghazy. « Fracture Resistance and Failure Mode of Mandibular Molar Restored by Occlusal Veneer : Effect of Material Type and Dental Bonding Surface ». Materials 14, n^o 21 (28 octobre 2021) : 6476. http://dx.doi.org/10.3390/ma14216476.

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This study assesses the effect of the material type (lithium disilicate, zirconia, and polymer-infiltrated ceramic) and dental bonding substrates (dentin, dentin with intra-coronal cavity, and dentin with composite filling) on the fracture resistance and failure mode of molars restored by occlusal veneers. Methods: Ninety occlusal veneers, fabricated from either lithium disilicate, zirconia, or polymer-infiltrated ceramic, were adhesively bonded to teeth prepared with either dentin, dentin with intra-coronal cavity, or dentin with composite filling. All specimens were thermally aged (5000 cycles), then load cycled (120,000 cycles). Each specimen was subjected to a compressive load through fracture, then was examined (×20) to identify the fracture type. Data were statistically analyzed. Results: Material type and dental substrate had no significant effect on the fracture resistance of adhesively retained occlusal veneer restorations. For each material, no significant differences were found between veneers bonded to dentin, dentin with intra-coronal cavity, and dentin with composite filling. Additionally, within each bonding substrate, there were no significant differences between lithium disilicate, zirconia, and polymer-infiltrated ceramic veneers. The adhesive failure was recorded mainly with zirconia occlusal veneer restorations. Conclusions: Considering the fracture results, lithium disilicate, zirconia, and polymer-infiltrated ceramic occlusal veneers perform well whatever the type of dental bonding surface. When the dental bonding surface varies, different occlusal veneer materials should be considered. Occlusal veneers bonded to dentin, dentin with composite filling, or dentin with an intra-coronal cavity exhibited a fracture resistance exceeding the average human masticatory forces in the molar area.

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ONUKI, Teppei, Ippei MURAYAMA, Takeyuki YAMAMOTO, Hirotaka OJIMA, Jun SHIMIZU et Libo ZHOU. « A015 Control of the incubation effects in pulsed laser micro machining on ferroelectric lithium niobate substrates ». Proceedings of International Conference on Leading Edge Manufacturing in 21st century : LEM21 2013.7 (2013) : 67–70. http://dx.doi.org/10.1299/jsmelem.2013.7.67.

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Nashimoto, Keiichi, Michael J. Cima, Paul C. McIntyre et Wendell E. Rhine. « Microstructure development of sol-gel derived epitaxial LiNbO3 thin films ». Journal of Materials Research 10, n^o 10 (octobre 1995) : 2564–72. http://dx.doi.org/10.1557/jmr.1995.2564.

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Film growth and microstructural evolution were investigated for sol-gel derived LiNbO3 thin films deposited on lattice-matched single-crystal substrates. Epitaxial LiNbO3 films of about 100 nm nominal thickness were prepared by spin coating a solution of the lithium niobium ethoxide on sapphire (0001) substrates and annealing at 400 °C or 700 °C in a humidified oxygen atmosphere. These films exhibited an epitaxial relationship with the substrate of the type LiNbO3 (0001) || α-Al2O3 (0001) and LiNbO3 [100] || α-Al2O3 [100] as determined by x-ray pole figure analysis. Transmission electron microscopy indicated the epitaxial films annealed at 400 °C consisted of slightly misoriented ∼5 nm subgrains and of numerous ∼10 nm enclosed pores. The microstructure and orientation development of these films was consistent with a heteroepitaxial nucleation and growth mechanism, in which epitaxial nuclei form at the substrate surface and grow upward into an amorphous and porous intermediate film: Epitaxial films annealed at 700 °C contained larger 150-200 nm subgrains and pinholes. Misorientations between adjacent subgrains appeared to be significantly smaller in films annealed at 700 °C than those in films annealed at 400 °C. Hydrolysis of the alkoxide precursor solution prior to spin coating promoted the development of polycrystalline films on single-crystal sapphire substrates. Infrared spectra and thermal analysis indicated that, independent of the degree of the solution hydrolysis, nucleation of LiNbO3 was immediately preceded by decomposition of an amorphous carbonate intermediate phase.

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Galashev, Alexander, et Alexey Vorob'ev. « An Ab Initio Study of Lithization of Two-Dimensional Silicon–Carbon Anode Material for Lithium-Ion Batteries ». Materials 14, n^o 21 (4 novembre 2021) : 6649. http://dx.doi.org/10.3390/ma14216649.

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This work is devoted to a first-principles study of changes in the structural, energetic, and electronic properties of silicene anodes during their lithium filling. Anodes were presented by silicene on carbon substrate and free-standing silicene. The ratio of the amount of lithium to silicon varied in the range from 0.06 to 1.125 for silicene on bilayer graphene and from 0.06 to 2.375 for free-standing silicene. It is shown that the carbon substrate reduces the stability of the silicene sheet. Silicene begins to degrade when the ratio of lithium to silicon (NLi/NSi) exceeds ~0.87, and at NLi/NSi = 0.938, lithium penetrates into the space between the silicene sheet and the carbon substrate. At certain values of the Li/Si ratio in the silicene sheet, five- and seven-membered rings of Si atoms can be formed on the carbon substrate. The presence of two-layer graphene imparts conductive properties to the anode. These properties can periodically disappear during the adsorption of lithium in the absence of a carbon substrate. Free-standing silicene adsorbed by lithium loses its stability at NLi/NSi = 1.375.

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Galashev, A. Y. « Computer development of silicene anodes for lithium-ion batteries : A review ». Electrochemical Materials and Technologies 1, n^o 1 (2022) : 20221005. http://dx.doi.org/10.15826/elmattech.2022.1.005.

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Lithium-ion batteries (LIB) have many advantages, the main ones being high energy density, long service life, small size, and low environmental pollution. This review is devoted to further development of LIBs based on quantum mechanical calculations in order to use them for energy storage in the future. Energetically favorite places occupied by lithium atoms on silicene are found. Lithium filling of free-standing two-layer silicene and single-layer silicene on graphene was studied. The geometric, energy, charging characteristics, as well as the open circuit voltage are determined. The effect of metallic (Al, Cu, Ni, Ag and Au) and non-metallic (C, SiC and BN) substrates on the geometric, energy and electronic properties of silicene has been studied. The effect of an intermediate nickel layer on the characteristics of the "silicene on a multilayer copper substrate" system has been studied. The effect of nuclear transmutation doping (NTD) of the silicene/graphite system with phosphorus on the density of electronic states of one- and two-layer silicene has been determined. Promising applications for silicene and the advantages of its use as an anode in a lithium-ion battery are discussed.

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Kamarád, Luděk, Stefan Pohn, Günther Bochmann et Michael Harasek. « Determination of mixing quality in biogas plant digesters using tracer tests and computational fluid dynamics ». Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 61, n^o 5 (2013) : 1269–78. http://dx.doi.org/10.11118/actaun201361051269.

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The total electricity demand of investigated biogas plants (BGP) makes up 7–8 % of the total electricity produced. Nearly 40 % of this energy is consumed just for mixing in digesters and the energy demand for mixing in some biogas plants can be even higher. Therefore, optimal mixing in anaerobic digesters is a basic condition for efficient plant operation and biogas production. The use of problematic substrates (e.g. grass silage or other fibrous substrates), installation of unsuitable mixing systems or inconvenient mixing intervals may lead to mixing problems. Knowledge about mixing in biogas digesters is still insufficient, so the objective of this study was to fill the information gaps in the literature by determining the minimal retention time of substrates fed into anaerobic digesters and to describe substrate distribution and washing out rates from investigated digesters. Two full-scale biogas plant digesters (2000 m3 and 1500 m3) using different mixing systems and substrates were investigated. To characterize the substrate distribution, lithium hydroxide monohydrate solutions were used for tracer tests at concentrations of 47.1 mg Li+ / kg TS and 46.6 mg Li+ / kg TS in digester. The tracer concentration in the digester effluents was measured during two hydraulic retention times and compared. Although the tracer was detected in the digester effluent at nearly the same time in both cases, the tracer tests showed very different distribution curves. The tracer concentration in effluent B grew much slower than in effluent A and no significant short circuiting streams were detected. Although the data calculated by computational fluid dynamics methods (CFD) showed a very good agreement with the full scale results, full comparison was not possible.

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Ackermann, K. E., B. G. Gish, M. P. Honchar et W. R. Sherman. « Evidence that inositol 1-phosphate in brain of lithium-treated rats results mainly from phosphatidylinositol metabolism ». Biochemical Journal 242, n^o 2 (1 mars 1987) : 517–24. http://dx.doi.org/10.1042/bj2420517.

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In cerebral cortex of rats treated with increasing doses of LiCl, the relative concentrations of Ins(1)P, Ins(4)P and Ins(5)P (when InsP is a myo-inositol phosphate) are approx. 10:1:0.2 at all doses. In rats treated with LiCl followed by increasing doses of pilocarpine a similar relationship occurs. myo-Inositol-1-phosphatase (InsP1ase) from bovine brain hydrolyses Ins(1)P, Ins(4)P and Ins(5)P at comparable rates, and these substrates have similar Km values. The hydrolysis of Ins(4)P is inhibited by Li+ to a greater degree than is hydrolysis of Ins(1)P and Ins(5)P. D-Ins(1,4,5)P3 and D-Ins(1,4)P2 are neither substrates nor inhibitors of InsP1ase. A dialysed high-speed supernatant of rat brain showed a greater rate of hydrolysis of Ins(1)P than of D-Ins(1,4)P2 and a lower sensitivity of the bisphosphate hydrolysis to LiCl, as compared with the monophosphate. That enzyme preparation produced Ins(4)P at a greater rate than Ins(1)P when D-Ins(1,4)P2 was the substrate. The amount of D-Ins(3)P [i.e. L-Ins(1)P, possibly from D-Ins(1,3,4)P3] is only 11% of that of D-Ins(1)P on stimulation with pilocarpine in the presence of Li+. DL-Ins(1,4)P2 was hydrolysed by InsP1ase to the extent of about 50%; both Ins(4)P and Ins(1)P are products, the former being produced more rapidly than the latter; apparently L-Ins(1,4)P2 is a substrate for InsP1ase. Li+, but not Ins(2)P, inhibited the hydrolysis of L-Ins(1,4)P2. The following were neither substrates nor inhibitors of InsP1ase; Ins(1,6)P2, Ins(1,2)P2, Ins(1,2,5,6)P4, Ins(1,2,4,5,6)P5, Ins(1,3,4,5,6)P5 and phytic acid. myo-Inositol 1,2-cyclic phosphate was neither substrate nor inhibitor of InsP1ase. We conclude that the 10-fold greater tissue contents of Ins(1)P relative to Ins(4)P in both stimulated and non-stimulated rat brain in vivo are the consequence of a much larger amount of PtdIns metabolism than polyphosphoinositide metabolism under these conditions.

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Mohd Shafie, Zulfida Mohamad Hafis, Abdul Latif Ahmad, Siew Chun Low, Sabine Rode et Bouchra Belaissaoui. « Lithium chloride (LiCl)-modified polyethersulfone (PES) substrate surface pore architectures on thin poly(dimethylsiloxane) (PDMS) dense layer formation and the composite membrane's performance in gas separation ». RSC Advances 10, n^o 16 (2020) : 9500–9511. http://dx.doi.org/10.1039/d0ra00045k.

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LiCl was incorporated in PES porous substrate fabrication methodology to influence the substrate's surface architectures and later, the resulting PDMS dense separating layer formation for composite membrane gas separation.

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Li, Hui, Yigeng Peng et Ruifeng Lu. « Substrate-Modulated Electric and Magnetic Resonances of Lithium Niobite Nanoparticles Illuminated by White Light ». Nanomaterials 12, n^o 12 (10 juin 2022) : 2010. http://dx.doi.org/10.3390/nano12122010.

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The manipulation of light at the nanoscale is important for nanophotonic research. Lithium niobite (LiNbO3), as an ideal building block for metamaterials, has attracted great interest for its unique properties in the field of nonlinear optics. In this paper, we numerically studied the effect of different substrates on the optical resonances of a LiNbO3 nanoparticle. The results show that the electric and magnetic resonances of such a system can be effectively adjusted by changing the substrate. Compared to the impact of dielectric substrate, the interaction between the LiNbO3 nanoparticle and the Au film shows a fascinating phenomenon that a sharp resonance peak appears. The multipole decomposition of the scattering spectrum shows that the size, shape of the LiNbO3 nanoparticle, and the thickness of the SiO2 film between the particle and the Au film have a significant impact on the electromagnetic resonance of the LiNbO3 nanoparticle. This work provides a new insight into LiNbO3 nanoparticles, which may have potential use in the design of dielectric nanomaterials and devices.

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Stallard, Joe C., Sundeep Vema, David S. Hall, Anthony R. Dennis, Megan E. Penrod, Clare P. Grey, Vikram S. Deshpande et Norman A. Fleck. « Effect of Lithiation upon the Shear Strength of NMC811 Single Crystals ». Journal of The Electrochemical Society 169, n^o 4 (1 avril 2022) : 040511. http://dx.doi.org/10.1149/1945-7111/ac6244.

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An experimental protocol is developed to measure the shear strength of NMC811 single crystals within the cathode of a lithium-ion cell. The cathode is placed upon a set of thick metallic substrates that possess a wide range of indentation hardness. For each choice of substrate, the top surface of the cathode is indented by a Vickers indenter to a sufficient depth that the cathode layer is subjected to an approximately spatially uniform compressive normal traction equal to the hardness of the substrate. The sensitivity of plastic flow and fracture of the single crystals to substrate hardness is determined by observation of the particles in the indented top surface of the cathode using a scanning electron microscope. It is found that the shear strength of fully lithiated NMC811 single crystals along their basal plane is 86 ± 12 MPa, and decreases to 39 ± 5 MPa upon cell charging (delithiation of the cathode). This implies that particle slip and fracture will occur under mild mechanical loading, for example by calendering during manufacture and by electrical cycling of the compacted cathode. The indentation protocol developed here has application to a wide range of single crystal cathode materials.

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Novák, P., T. Khel, J. Vopravil et J. Lagová. « Do Andosols occur in the Czech Republic ? » Soil and Water Research 5, No. 4 (1 décembre 2010) : 161–71. http://dx.doi.org/10.17221/24/2010-swr.

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The aim of this contribution was either to confirm or refuse the supposition that there are soils on the volcanic effusive rocks in the Bruntál district which can be assigned to the referential group of Andosols. The conditions for the genesis of Andosols are described and the diagnostic criteria of the andic process are defined both according to the principles of the WBR/FAO 2006 classification and according to the Slovak MKSPS 2000 classification system. In the Czech classification system, the diagnostics of Andosols has not yet been described or defined because their occurrence on the territory of the Czech Republic has not been confirmed till now. On the Velký Roudný volcanic dome (780 m), samples from two profiles were taken and described: one from below the summit as a sample of forest soil, and the other from the terraced, grass-covered foot of the hill, formerly used as a ploughed land. The samples from the two profiles were processed, and analyses were carried out according to both the classification systems mentioned above. The results of the analyses were subsequently evaluated. It was discovered that both evaluated profiles conformed to most of the diagnostic characteristics of andic development according to both WRB 2006 and the Slovak 2000 classification systems. Both evaluated profiles could be then classified – according to WRB 2006 – as Vitric Andosol (Dystric) and Vitric – Umbric Andosol (Dystric, Colluvic), respectivelly; according to Slovak Classification System as Andic Cambisols. The occurrence of soils with andic development in the Czech Republic was thus confirmed. The conclusion drawn by some authors (eg. in US Taxonomy) that a higher content of volcanic glass and a substrate of andesite type are not an indispensable condition for the creation of soils classified as Andosols was also confirmed. Likewise, according to the WRB criteria, a melanic humus horizon is not a necessary condition. Because of the difficulties in distinguishing the types, the Czech classification system recommends that a humic andic horizon should be evaluated as molic. We assume that in some cases it could be better classified as umbric. A preliminary proposal has been put forward to insert the Andozem soil types in Taxonomic Soil Classification System of the Czech Republic: Haplic Andosol, Vitric Andosol, Lithic Andosol, Umbric Andosol, but the properties and criteria of those soils will have to be defined precisely. One problem which will also have to be resolved is how to allocate the profiles displaying andic properties either to the proposed subtype of Cambic Andosol or to the subtype of Andic Cambisol (outside the referential class of Andsols). This issue is, indeed, not dealt with satisfactorily either by the Slovak system or the worldwide WRB 2006 classification, either.

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