Získávání poznatků: Přímé pozorování či měření Proxy palimpsest
2 Earth science: Probing the core's light elements. Duffy, Thomas Nature. 479(7374):480-481, November 24, 2011. DOI: 10.1038/479480a Figure 1 | Cross-section of Earth's interior. Depths for the various regions are indicated on the left and corresponding pressures (in gigapascals) on the right. The core is mainly composed of iron (Fe) and nickel (Ni), with some unknown lighter elements. By comparing laboratory measurements with seismic data, Huang et al.3 place new constraints on the identity of these light elements in the core.
a diamant, b-grafit, c-londsdaleit, d-f fullereny, g – amorfní C, h – nanotrubice, CO2 methan
AK Geim & IV Grigorieva Nature 499, 419-425 (2013) doi:10.1038/nature12385 Building van der Waals heterostructures.
AK Geim & IV Grigorieva Nature 499, 419-425 (2013) doi:10.1038/nature12385 State-of-the-art van der Waals structures and devices.
Cordier et al. 1 have analysed images produced using electron backscatter diffraction to identify grain-boundary disclinations in olivine aggregates. Shown here is a cross- section of a sample deformed at high stress. Different colours denote different crystallographic orientations of the crystals that make up the aggregate. Scale bar, 20 μm. 1 Nature 9March 2014, 42 Olivín (Mg,Fe) 2 [SiO 4 ]
Reformulating table salt.When sodium chloride (NaCl) is squeezed by diamond anvils at high temperatures and under Cl- or Na-rich conditions, compounds such as NaCl3 or Na3Cl can be formed. J Ibáñez Insa Science 2013;342:1459-1460 Published by AAAS
Fig. 2Crystal structures of Na chlorides and NaCl 7.(A) Pm3-NaCl 7. (B) Pnma-NaCl 3. (C) Pm3n-NaCl 3. (D) P4/mmm-Na 3 Cl. (E)P4/m-Na 3 Cl 2. (F) Cmmm-Na 3 Cl 2. (G) P4/mmm-Na 2 Cl. (H) Cmmm-Na 2 Cl. (I) Imma-Na 2 Cl. Blue and green spheres denote Na and Cl atoms, respectively. W Zhang et al. Science 2013;342:1502-1505
Metal-organic framework (MOF) structures are amenable to expansion and incorporation of multiple functional groups within their interiors. (A) The isoreticular expansion of MOFs maintains the network’s topology by using an expanded version of the parent organic linker. Examples of catalysis in MOFs are shown in the large space created by IRMOF-74-XI; Me is a methyl group. (B) Conceptual illustration of a multivariate MOF (MTV-MOF) whose pores are decorated by heterogeneous mixtures of functionalities that arrange in specific sequences. (Background) Optical image of zeolitic imidazolate framework (ZIF) crystals.
Fig. 3 Isoreticular expansion of metal-organic frameworks H Furukawa et al. Science 2013;341:123 Published by AAAS
Fig. 6 Examples of creating heterogeneity within crystalline materials.(A) MTV-MOF-5, in which a heterogeneous mixture of functionalities decorates the interior of the crystals to provide an environment capable of highly selective binding of carbon dioxide. H Furukawa et al. Science 2013;341:1230444 Published by AAAS
Room at the bottom.Among the crystalline arrays of atom-like molecular cluster units created by Roy et al. is a giant analog of the structure formed by NaCl (rock salt). P Batail Science 2013;341:135-136 Published by AAAS
Fig. 1 Structures of the nanoscale atoms as measured by SCXRD.In the figure, the clusters are depicted on the same size scale. X Roy et al. Science 2013;341:157-160 Published by AAAS
Cryo-electron tomogram of a fraction of the cytoplasm of a human cell. Microtubules are coloured in orange, stress fibres in grey, protein complexes in green, membranes in cyan and vesicular contents in yellow.
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