ABSTRACT
Plate-boundary fault rupture during the 2004 Sumatra-Andaman subduction earthquake extended closer to the trench than expected, increasing earthquake and tsunami size. International Ocean Discovery Program Expedition 362 sampled incoming sediments offshore northern Sumatra, revealing recent release of fresh water within the deep sediments. Thermal modeling links this freshening to amorphous silica dehydration driven by rapid burial-induced temperature increases in the past 9 million years. Complete dehydration of silicates is expected before plate subduction, contrasting with prevailing models for subduction seismogenesis calling for fluid production during subduction. Shallow slip offshore Sumatra appears driven by diagenetic strengthening of deeply buried fault-forming sediments, contrasting with weakening proposed for the shallow Tohoku-Oki 2011 rupture, but our results are applicable to other thickly sedimented subduction zones including those with limited earthquake records.
ABSTRACT
With controlled nanometre-sized pores and surface areas of thousands of square metres per gram, metal-organic frameworks (MOFs) may have an integral role in future catalysis, filtration and sensing applications. In general, for MOF-based device fabrication, well-organized or patterned MOF growth is required, and thus conventional synthetic routes are not suitable. Moreover, to expand their applicability, the introduction of additional functionality into MOFs is desirable. Here, we explore the use of nanostructured poly-hydrate zinc phosphate (α-hopeite) microparticles as nucleation seeds for MOFs that simultaneously address all these issues. Affording spatial control of nucleation and significantly accelerating MOF growth, these α-hopeite microparticles are found to act as nucleation agents both in solution and on solid surfaces. In addition, the introduction of functional nanoparticles (metallic, semiconducting, polymeric) into these nucleating seeds translates directly to the fabrication of functional MOFs suitable for molecular size-selective applications.
Subject(s)
Organometallic Compounds/analysis , Phosphates/analysis , Polymers/analysis , Zinc Compounds/analysis , Biosensing Techniques/methods , Catalysis , Crystallization/methods , Models, Molecular , Organometallic Compounds/chemical synthesis , Organometallic Compounds/metabolism , Phosphates/chemical synthesis , Phosphates/metabolism , Polymers/chemical synthesis , Polymers/metabolism , Quantum Dots , Semiconductors , Solutions/chemistry , Surface Properties , Zinc Compounds/chemical synthesis , Zinc Compounds/metabolismABSTRACT
An image filter has been used to test a simple model describing the dynamical scattering of electrons that have suffered multiple interactions with plasmons. Semi-quantitative agreement is observed in both Si and TiAl under quasi two-beam conditions. In the latter material it is shown that the classical Hirsch, Howie, Whelan analysis of contrast due to dislocations can be carried out in images produced by electrons that have suffered as many as five interactions with plasmons and at thicknesses at which the unfiltered and zero loss images show no contrast.
