A femtosecond all-fiber laser source incorporating a cw mode-locked Yb-doped silica fiber oscillator and amplifier has been used to synchronously pump an optical parametric oscillator based on periodically poled lithium niobate. The signal output, consisting of 330-fs pulses at a 54-MHz repetition rate and average powers up to 90 mW, was tuned from 1.55 to 1.95microm , with a corresponding idle...

The preparation of different carbon-shell morphology microspheres and controllable surface area via using thermoplastic polymers as carbon source was still a challenge. In addition, the unique structure porous Silica@Carbon (Sil@C) not only can provide larger active site, but also have characteristics high mechanical strength easy modification. Herein, we report simple method to in-situ fixatio...

We screened soil samples for CO(2)-requiring extreme oligotrophs similar to Rhodococcus erythropolis N9T-4, which can grow on a basal salt agar medium without an organic carbon source. From 387 soil samples, three isolates were obtained and identified as Streptomyces spp. by 16S rDNA analysis. The isolates required gaseous CO(2) for growth and grew on a basal salt medium solidified by silica ge...

We report observations and measurements of the inscription of fiber Bragg gratings (FBGs) in two different types of microstructured polymer optical fiber: few-mode and an endlessly single mode. Contrary to the FBG inscription in silica microstructured fiber, where high-energy laser pulses are a prerequisite, we have successfully used a low-power cw laser source operating at 325 nm to produce 1 ...

The passage of a free-electron beam through a nanohole in a periodically layered metal-dielectric structure creates a new type of tunable, nanoscale radiation source--a "light well". In the reported demonstration, tunable light is generated at an intensity of approximately 200 W/cm(2) as electrons with energies in the 20-40 keV range are injected into gold-silica well structures with a lateral ...

ethylene polymerization was carried out using phillips chromium catalyst based on silica supports such as silicaaerogel, sio2 (grace 643), and titanium modified sio2 (g 643), and the results were compared with othercatalysts based on sio2 (aldrich), sba-15(hex), sba-15(sp) and mcm-41. a combination of tga, dsc, xrd,nitrogen adsorption, sem, icp, ftir and other analyses were used to characterize...

Vinasse was successfully utilized to synthesize carbon–silica composite with a low-cost silica source available in Thailand (sodium silicate, Na2SiO3) and most commonly used source, tetraethyl orthosilicate (TEOS). The composites were prepared by simple one-step sol–gel process varying the vinasse (as carbon source) (Na2SiO3 or TEOS) weight ratio. resulting characterized N2 adsorption, moisture...

“Silica,” is a term which refers broadly to the mineral compound silicon dioxide (SiO2). Silica can be crystalline or amorphous. Crystalline silica is significantly more hazardous to employees than amorphous silica. In addition to causing the disabling and irreversible lung disease known as silicosis, crystalline silica has been classified as a human carcinogen by the International Agency for R...

Abstract The photocatalytic process of phenol oxidation and Cr(VI) reduction in the presence nano-silica modified titania was carried out. activity composites tested using two different light sources. photocatalysts with 10% nanosilica showed highest activity. calcination temperature (200–800 o C) significantly determined sensitivity obtained materials to source used. Photocatalysts alternately...

Liquidus phase relationships determined on the join CaAIzSi20 8 (anorthi te)-MgzSiO 4 (forsteri te)-SiO 2 (quartz) at 10 kbar show that increasing pressure causes the forsterite and anorthite primary phase fields to shrink and the spinel, enstatite and silica fields to expand. The boundary line between the enstatite and forsterite fields and that between the enstatite and quartz fields both mov...