Understanding the nature of NH3-coordinated active sites and the complete reaction schemes for NH3-SCR using Cu-SAPO-34 catalysts

Cu-SAPO-34 zeolite catalysts show excellent NH3-SCR performance at low temperature, which is due to the catalytic capacity of copper species.

Growth process control produces high-crystallinity and complete-reaction perovskite solar cells

The growth process control (GPC) method, a new method which is better than thermal evaporation, for producing high-crystallinity perovskites by controlling the growth time in a low vacuum, is explored in this work.

Effects of Aluminum Powder on Ignition Performance of RDX, HMX, and CL-20 Explosives

As a kind of high explosives, aluminized explosive cannot release the energy maximumly, which is a key problem. Using DTA-TG equipment, the ignition performance of three kinds of aluminized explosives (RDX, HMX, and CL-20) with different mass percentages of aluminum powder (0%, 10 wt.%, 20 wt.%, and 30 wt.%) was investigated. The results showed that the energy release of the HMX/Al composite explosive with 10 wt.%, 20 wt.%, and 30 wt.% aluminum powder was only equivalent to 80%, 65%, and 36% of pure HMX, respectively. It was similar to RDX/Al and CL-20/Al composite explosives, except the CL-20/Al mixture with 10% aluminum powder. Rather than participating in the ignition and combustion, the aluminum powder does effect the complete reaction of RDX, HMX, and CL-20 in the initial stage of ignition or in the lower temperature area of the boundary.

Influences of CO2 Bubbling Types on Preparation of Calcite Nanoparticles by Carbonation Process

This study investigates the comparison of influences of CO2 bubbling into the calcium hydroxide (Ca(OH)2) slurry through a microbubble generator (MBG) and an ordinary CO2 generator (OCG) on the preparation of calcite nanoparticles by a carbonation method. Each obtained precipitate was characterized using XRD, SEM and particle size analyses. During the carbonation process at each CO2 flow rates, it was determined that the MBG generates tiny bubbles whereas an increase in CO2 flow rates led to an increase bubble size when the OCG was used. The flow rate of CO2 was not an important parameter with using the MBG as calcite nanoparticles were prepared (<125 nm) at each CO2 flow rates. The necessary time for the complete reaction decreases with an increase in the CO2 flow rates through the MBG in comparison to the OCG. To produce calcite nanoparticles with a high production recovery in shorter times, the MBG should be adopted to the carbonation reactor.