a highly efficient procedure for the preparation of n,n'-alkylidenebisamides in the presence of bf3.sio2 as a catalyst is described. n,n'-alkylidenebisamides have been prepared via one-pot three-component condensation reaction of various aldehydes and amides. all of the reactions proceeded in high yields and in moderately short reaction times.

We performed comparative studies of radiation-induced interface trap generation at n-6H-SiC/SiO2 and Si/SiO2 interfaces for high doses of low energy x-rays in the range 0 to 200 Mrad (Si). We found that radiation-induced interface trap generation at the n-6H-SiC/SiO2 interface is much lower than at the Si/SiO2 interface. The experiments provide evidence of interface trap generation near the SiC...

A new form of finite silica with edge-sharing SiO2 units connected in a ring is proposed. High-level density-functional calculations for (SiO2)(N), N=4-14, show the rings to be energetically more stable than the corresponding (SiO2)(N) linear chains for N>11. The rings display frequency modes in remarkable agreement with infrared bands measured on dehydrated silica surfaces indicating their pot...

We have been prepared Semiconducting oxide material like TiO2, SiO2, TiO2-SiO2 and TiO2/SiO2 thin films for taken different composition by using hydrothermal method. All these elements were deposited on the glass substrate. In this films are acted on the p and n type working with the majority carrier are recombination of electron and hole .This material is N type but it will acted p-type Ti and...

Triple-layer omnidirectional reflectors (ODRs) consisting of a semiconductor, a quarter-wavelength transparent dielectric layer, and a metal have high reflectivities for all angles of incidence. Internal ODRs (ambient material's refractive index n >> 1.0) are demonstrated that incorporate nanoporous SiO2, a low-refractive-index material (n = 1.23), as well as dense SiO2 (n = 1.46). GaP and Ag s...

Acute paraquat (PQ) poisoning is one of the most common forms of pesticide poisoning. Oxidative stress and inflammation are thought to be important mechanisms in PQ-induced acute lung injury (ALI). Selenium (Se) can scavenge intracellular free radicals directly or indirectly. In this study, we investigated whether porous Se@SiO2 nanospheres could alleviate oxidative stress and inflammation in P...