A super-resilient and highly sensitive graphene oxide/cellulose-derived carbon aerogel

By engineering an ordered lamellar texture and stabilizing the structure during carbonization, an ultralight carbon aerogel with superior mechanical performances and high linear sensitivity is successfully fabricated.

Akkalkan deposit of bentonite clays (Southeast Kazakhstan): formation conditions and prospects for technological use

The article presents the results of the bentonite clays study of Akkolkanskoye deposit, located in South-Eastern Kazakhstan. Based on the mapping, four main types of bentonites were identified: light gray argillite-like clay; dark gray clay lamellar and crushed stone morphology; waxy light brown and pale yellow clay lamellar texture; black plastic clay. Mineralogical study of these varieties allowed to establish the relationship of crystal-morphological features of the main rock-forming mineral in clays with the conditions of their formation and with the technological properties of bentonite raw materials for use in various industries.

Ferroelasticity of SrCo0.8Fe0.2O3–δperovskite-related oxide with mixed ion–electron conductivity

A group-theoretical analysis was carried out to determine the possible orientation states of domains formed as a result of the `perovskite–brownmillerite' phase transition in SrCo0.8Fe0.2O2.5oxide with mixed ion–electron conductivity (MIEC). The results of the theoretical analysis agree with the experimental data obtained in the study of the SrCo0.8Fe0.2O2.5microstructure by means of transmission electron microscopy. Brownmillerite SrCo0.8Fe0.2O2.5(BM) has a lamellar texture composed of 90° twins 60–260 nm in size; the 〈010〉BMand 〈101〉BMdirections are linked through twinning in accordance with the predictions of the group-theoretical analysis. The presence of twins and their switching under mechanical load provide evidence that the perovskite–brownmillerite phase transition in SrCo0.8Fe0.2O2.5is ferroelastic. Comparative analysis of the phenomena observed for ferroelectrics and MIEC oxides indicates their similarity based on the common nature of ferroelectricity and ferroelasticity, and allows us to suppose that nonstoichiometric SrCo0.8Fe0.2O3−δwith compositional disorder may be considered (in terms of its microstructural features) a `relaxor ferroelastic'.

Visible-Light Driven C3N4 Photocatalysts Prepared by a Thermal Decomposition Process

The C3N4was synthesized by directly thermal decomposition melamine in N2atmosphere furnace. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). The results show that C3N4indicates the typical slate-like, stacked lamellar texture of about 1μm in diameter, and a band gap of about 2.78 eV. The photocatalytic experiment shows the good photocatalytic activity for the decomposition of methyl orange (MO) under visible-light irradiation, which is attributed to the strong visible-light absorption.

Scanning texture analysis of lamellar bone using microbeam synchrotron X-ray radiation

Texture analysis with microbeam scanning diffraction enables the local mapping of three-dimensional crystallite orientation in heterogeneous natural and synthetic materials. Cortical (compact) bone is an example of a hierarchically structured biocomposite, which is built mainly of cylindrical osteons, having a lamellar texture at the micrometre level. In this work, a combination of microbeam synchrotron X-ray texture analysis with thin sections of osteonal bone is used to measure the three-dimensional distribution of thec-axis orientation of the mineral apatite in bone with positional resolution of 1 µm. The data reduction procedure needed to go from the stereographic projection of X-ray intensity to the determination of the local orientation of mineralized collagen fibrils is described. The procedure can be applied to other mineralized tissues (such as trabecular bone and chitin) with micrometre scale and biologically controlled fibrillar texture.

Phase Orientation of a TiC-TiB2-SiC Ternary Eutectic Composite Prepared by An FZ Method

The TiC-TiB2-SiC system was a ternary eutectic, whose eutectic composition was 34TiC-22TiB2-44SiC (mol%). A TiC-TiB2-SiC ternary eutectic composite were synthesized via the floating zone method using TiC, TiB2 and SiC powders as starting materials. The TiC-TiB2-SiC eutectic composite showed a lamellar texture. TiC(022), TiB2(010) and SiC(111) of the eutectic composite were perpendicular to the growth direction. The TiC-TiB2-SiC ternary eutectic composite had a specific relationship among the crystal planes: TiC[011]//TiB2[010]//SiC[112], TiC(200)// TiB2(001)//SiC( 402 ) and TiC(111)//TiB2(101)//SiC( 220 ).

Shell morphology, shell texture and species discrimination of Caribbean Tucetona (Bivalvia, Glycymeridae)

Previous descriptions of Tucetona lack a consistent system using diagnostic characters and only two recent Caribbean ‘species' are recognized. In this study, textural and structural features of the Tucetona shell are examined and used as the basis for comparison to other glycymerids and in the recognition of morphospecies. Standard diagnostic characters based mainly on the cross-sectional shape of ribs and on hinge teeth ontogeny are presented and used to distinguish six recent Caribbean morphospecies. The shell texture has been examined by light and scanning electron microscopy, showing the interior of glycymerid hinge teeth structured by two bundles of crossed lamellar texture. Whereas European Glycymeris examined for comparison correspond in their hinge plate textures to the one found in Tucetona, differences from a Caribbean Glycymeris sp. are described. Simple lamellar, crossed-lamellar and cone complex crossed-lamellar textures showed the same basic crystallite subunits.