نتایج جستجو برای: oxides

تعداد نتایج: 21448  

Journal: :Bulletin of environmental contamination and toxicology 2003
C Y Chuang J C Hung C Y Yang Y C Ma F C Sung

Journal: :Chemical communications 2007
Mingyu Niu Hua Fu Yuyang Jiang Yufen Zhao

We have developed efficient copper-catalyzed additions of P(O)H compounds to alkynes, and the reactions provided the regio- and stereoselective E-alkenylphosphine oxides under catalysis of the commercially available and inexpensive copper catalyst system CuI/ethylenediamine. This finding is the first example of copper-catalyzed hydrophosphinylation of alkynes to synthesize alkenylphosphine oxides.

Journal: :Organic & biomolecular chemistry 2012
Zhi-Wei Guo Jian-Wu Xie Ce Chen Wei-Dong Zhu

A highly regio-, chemo-, diastereo- and enantioselective organocatalytic [4 + 1] annulation of 2-halo-1,3-dicarbonyl compounds with Morita-Baylis-Hillman adducts catalyzed by commercially available, low cost quinidine for the preparation of synthetically unique and medicinally multi-functionalized isoxazoline N-oxides with three stereogenic centers including adjacent quaternary and tertiary ste...

Journal: :international journal of nanoscience and nanotechnology 2014
m. khorasani-motlagh h. vahidi m. noroozifar

the perovskite-type oxides strontium-substituted lanthanum nickelate (lsno) were prepared by a coprecipitation method in the present of octanoic acid as surfactant. the phase composition, morphology,lattice parameters and size of nanoparticles in these materials were characterized through fourier transform infrared spectroscopy (ft-ir), x-ray diffraction (xrd), scanning electron microscopy (sem...

Journal: :ACS applied materials & interfaces 2014
Peng Du Lan Ma Yinghui Cao Di Li Zhenyu Liu Zhenxin Wang Zaicheng Sun

Surface enhancement Raman scattering (SERS) is a powerful technique for detecting low-concentration analytes (chemicals and biochemicals). Herein, a high-performance SERS biosensing system has been created by using highly stable Ag@oxides nanoplates as enhancers. The Ag nanoplates were stabilized by coating a uniform ultrathin layer of oxides (SiO2 or TiO2) on the Ag surface through a simple so...

2012
Yi Zhao

High permittivity (k) gate dielectric films are widely studied to substitute SiO2 as gate oxides to suppress the unacceptable gate leakage current when the traditional SiO2 gate oxide becomes ultrathin. For high-k gate oxides, several material properties are dominantly important. The first one, undoubtedly, is permittivity. It has been well studied by many groups in terms of how to obtain a hig...

Journal: :Nanoscale 2014
Maria Vasilopoulou

In this work, the effect of surface hydrogenation of different metal oxides, in particular molybdenum and tungsten oxides widely used to enhance hole extraction and zinc and titanium oxides widely used to enhance electron extraction, on the nanomorphology and the charge generation efficiency of polymer blend solar cells is investigated. It was found that photoactive layers based on blends using...

2012
Abhishek Verma Anup Mishra

The scaling of complementary metal oxide semiconductor (CMOS) transistors has led to the silicon dioxide layer used as a gate dielectric becoming so thin (1.4 nm) that its leakage current is too large. It is necessary to replace the SiO2 with a physically thicker layer of oxides of higher dielectric constant (κ) or ‘high K’ gate oxides such as hafnium oxide and hafnium silicate. Little was know...

Group VIII B metal oxides supported on gamma-alumina were investigated as catalysts and promoters of MoO3 hydrodesulfurization catalysis. Superior promotion was observed in PbO promoted catalyst compared to that of CoO, the typically accepted promoter. Other metal oxides, SnO and Ho2O3 exhibited reasonable hydrodesulfurization catalysis promotion but lower than for CoO promoted catalyst.

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