نتایج جستجو برای: cerium

تعداد نتایج: 3705  

Journal: :Beilstein Journal of Organic Chemistry 2006
OP Chevallier ME Migaud

Standard reaction conditions for the desilylation of acetylated furanoside (riboside, arabinoside and xyloside) derivatives facilitate acyl migration. Conditions which favour intramolecular and intermolecular mechanisms have been identified with intermolecular transesterifications taking place under mild basic conditions when intramolecular orthoester formations are disfavoured. In acetyl ribos...

Journal: :journal of ultrafine grained and nanostructured materials 2015
majid farahmandjou mahsa zarinkamar

cerium oxide (ceo2) or ceria has been shown to be an interesting support material for noble metals in catalysts designed for emission control, mainly due to its oxygen storage capacity. ceria nanoparticles were prepared by precipitation method. the precursor materials used in this research were cerium nitrate hexahydrate (as a basic material), potassium carbonate and potassium hydroxide (as pre...

1998
Joseph P. Dunn Jih-Mirn Jehng Du Soung Kim Laura E. Briand Harvey G. Stenger Israel E. Wachs

The interactions between surface sulfate and surface vanadate species present on sulfated supported vanadia catalysts under dehydrated conditions have been investigated with infrared and Raman spectroscopies. The surface sulfate species present on sulfated TiO2, ZrO2, and Al2O3 supports and V2O5/TiO2, V2O5/ZrO2, and V2O5/Al2O3 catalysts have identical molecular structures, i.e., (M-O)3SdO, wher...

2009

A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts of cerium (IV), based on the catalytic effect of Ce (IV) on the oxidation of Nile blue (NB) by potassium periodate is described. The reaction rate was monitored spectrophotometrically by measuring the decrease in absorbance of NB at 636 nm. The detection limit of the method was 0.15 g ml and the line...

2015
Joseph C. Bear Paul D. McNaughter Charles W. Dunnill Ramesh K. Guduru

Nickel-doped cerium dioxide nanoparticles exhibit room temperature ferromagnetism due to high oxygen mobility within the doped CeO2 lattice. CeO2 is an excellent doping matrix as it can lose oxygen whilst retaining its structure. This leads to increased oxygen mobility within the fluorite CeO2 lattice, leading to the formation of Ce3+ and Ce4+ species and hence doped ceria shows a high propensi...

2016
Keren Jiang Chin Li Cheung

Cerium oxide, or ceria (CeO x : x = 1.5 to 2), has been widely used as a heterogeneous catalyst. Ceria has several properties make it high catalytic active: the fluctuating valence of cerium, the high oxygen storage capacity and high oxygen mobility in the nonstoichiometric ceria. With the high abundance of cerium on earth crust, ceria is a highly effective alternative of the noble metal cataly...

2011
P. C. Ricci C. M. Carbonaro A. Casu C. Cannas A. Anedda

The optical and structural properties of sol–gel prepared polycrystalline films of Cerium doped Lutetium and Yttrium oxyorthosilicates (Ce:LYSO) are investigated by means of optical spectroscopy, XRD diffraction and Raman spectroscopy. The sol–gel samples are compared to commercially available Ce-doped LYSO single crystals, and a detailed study of the emission properties from the different ceri...

2015
Lavinia Fiorani Maurizio Passacantando Sandro Santucci Stefano Di Marco Silvia Bisti Rita Maccarone Thomas Langmann

The first target of any therapy for retinal neurodegeneration is to slow down the progression of the disease and to maintain visual function. Cerium oxide or ceria nanoparticles reduce oxidative stress, which is known to play a pivotal role in neurodegeneration. Our aim was to investigate whether cerium oxide nanoparticles were able to mitigate neurodegeneration including microglial activation ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2015
Thomas Willers Fabio Strigari Zhiwei Hu Violetta Sessi Nicholas B Brookes Eric D Bauer John L Sarrao J D Thompson Arata Tanaka Steffen Wirth Liu Hao Tjeng Andrea Severing

The interplay of structural, orbital, charge, and spin degrees of freedom is at the heart of many emergent phenomena, including superconductivity. Unraveling the underlying forces of such novel phases is a great challenge because it not only requires understanding each of these degrees of freedom, it also involves accounting for the interplay between them. Cerium-based heavy fermion compounds a...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2002
Mohammad Reza Ganjali Tahereh Poursaberi Morteza Hosseini Masoud Salavati-Niasary Mohammad Yousefi Mojtaba Shamsipur

A highly selective PVC membrane electrode based on a cerium-salen complex was prepared. The sensor displays an anti-Hofmeister selectivity sequence with a preference for iodide ion over many common organic and inorganic anions. The proposed electrode exhibits a near-Nernstian behavior over a wide concentration range (5.0 x 10(-2) - 8.0 x 10(-6) M) with a slope of 57.5 mV per decade, and a detec...

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