There is much less index access and no index AND'ing so that the overall performance can be one or two order of magnitude better - depending on predicate selectivity.

A successful technical catalyst is required not only to have high activity, selectivity and heat-resistance, but also enough high mechanical strength in order to resist some mechanical stresses.

In order to improve the sensitivity and selectivity and to increase the detectable gas compositions, the chemical gas sensor is investigated and applied to explore natural gas and oil in sea.