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Isomorphic Substitution of Silicon in SAPO-37
1989Isomorphic substitution of Al-P pairs for Si occurs in siliceous SAPO-37 crystals. 29Si MAS NMR shows that such crystals are composed of aluminosilicate and silicoaluminophosphate domains. The aluminosilicate parts have unusual Si, Al ordering. Si-enriched SAPO-37 has enhanced catalytic activity.
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Role of germanium in isomorphic substitutions in quartz
Geochemistry International, 2015We investigated the kinetics of the incorporation of Al, Ti, and Ge impurities into the crystal structure of natural quartz at the second stage of isomorphic substitution after quartz crystallization. Quartz samples were experimentally annealed to model the accumulation of isomorphic admixtures under natural conditions.
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Singular words, invertible substitutions and local isomorphisms
1995One-dimensional (1D) quasiperiodic Schrodinger equations have been studied by many authors in recent years (see for example [21]). In particular, much attention has been focussed on quasiperiodic potentials that are derived from the Fibonacci sequence, providing a. kind of prototype models for studying quasiperiodic systems. Starting from the Fibonacci
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Integrative oncology: Addressing the global challenges of cancer prevention and treatment
Ca-A Cancer Journal for Clinicians, 2022Jun J Mao,, Msce +2 more
exaly
Isomorphous substitutions in vanadate garnets
Neues Jahrbuch für Mineralogie - Abhandlungen, 2006K. Iishi, Y. Ikuta
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Synthesis of isomorphously boron-substituted mesoporous MCM-48
2007Abstract A series of boron-substituted MCM-48 mesoporous molecular sieves over a wide range of boron content (Si/B ratio from 100 to 2 in the reaction mixture) have been synthesized hydrothermally and characterized by ICP, XRD, N2 adsorption, TG, SEM, and 11B and 29Si MAS-NMR. Only tetrahedral BO4 units in the framework were found in as-synthesized B-
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Isomorphous Substitution in Zeolitic Frameworks Procedures and Characterization
1991Abstract Isomorphous substitution of T element in a molecular sieve material is very interesting in order to modify its acidic or redox catalytic and shape selective properties. Different ways to perform such a substitution are now well established either during synthesis or post synthesis including solid-solid reaction between the zeolite and ...
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Multidisciplinary standards of care and recent progress in pancreatic ductal adenocarcinoma
Ca-A Cancer Journal for Clinicians, 2020Aaron J Grossberg +2 more
exaly