نتایج جستجو برای: eggshell supported cuii catalyst
تعداد نتایج: 236951 فیلتر نتایج به سال:
silica supported phosphorus pentoxide (p2o5·sio2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.
The dorsal anterior region of the follicle cells (FCs) in the developing Drosophila egg gives rise to the respiratory eggshell appendages. These tubular structures display a wide range of qualitative and quantitative variations across Drosophila species, providing a remarkable example of a rapidly evolving morphology. In D. melanogaster, the bone morphogenetic protein (BMP) signaling pathway is...
A robust and efficient non-precious metal catalyst for hydrogen evolution reaction is one of the key components for carbon dioxide-free hydrogen production. Here we report that a hierarchical nanoporous copper-titanium bimetallic electrocatalyst is able to produce hydrogen from water under a mild overpotential at more than twice the rate of state-of-the-art carbon-supported platinum catalyst. A...
Carbon-supported platinum (Pt) and palladium (Pd) alloy catalyst has become a promising alternative electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. In this work, the synthesis of highly active and stable carbon-supported Pt-Pd alloy catalysts is reported with a room-temperature electron reduction method. The alloy nanoparticles thus prepared show a pa...
In this research, a metal oxide nanocatalyst of ZnO supported copper oxide is reported as a highly efficient recyclable catalyst for the chemoselective synthesis of 1,1-diacetates. The catalyst was synthesized by co-precipitation method and characterized by XRD, BET specific surface area, ESEM, EDS and TEM analysis. A wide range of aldehydes, including aromatic and aliphatic aldehydes were conv...
A simple and efficient method for the chemoselective 1,1-diacetate protection of aromatic aldehydes with acetic anhydride by using Ni2+ supported on hydroxyapatite-core-shell magnetic γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp-Ni2+) under solvent free conditions. This method has several advantages, including high yield, short reaction time, simple work-up and recyclable property of the catalyst. The ca...
In this research, spherical α-Fe2O3 nanoparticles (NPs) were supported on the surface of 12-tungstosilicic acid (12-TSA.7H2O) as a catalyst support, using two different Forced Hydrolysis and Reflux Condensation (FHRC) and Solid-State Dispersion (SSD) methods. α-Fe2O3 and 12-TSA.7H2O were synthesized due to previous reports. A...
The eggshell of the hen is a highly ordered and mineralised structure, which is sequentially deposited within an acellular milieu – the uterine fluid secreted by the distal oviduct. Spherulitic crystal growth of calcite is initiated on organic aggregates on surface of the eggshell membranes, followed by competition between radial crystallites for space to form a compact columnar biomineral. The...
Using ancient DNA (aDNA) extracted from eggshell of the extinct moa (Aves: Dinornithiformes) we determined the species composition and number of eggs found in a late thirteenth century earth oven feature at Wairau Bar (South Island, New Zealand) – one of New Zealand’s most significant archaeological sites. Mitochondrial and nuclear DNA signatures confirmed this oven feature contained fragments ...
Embryos of oviparous Reptilia (=turtles, lepidosaurs, crocodilians and birds) extract calcium for growth and development from reserves in the yolk and eggshell. Yolk provides most of the calcium to embryos of lizards and snakes. In contrast, the eggshell supplies most of the calcium for embryonic development of turtles, crocodilians and birds. The yolk sac and chorioallantoic membrane of birds ...
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