Fused silica has 2 meanings: previously fused silica and presently fused silica.

Previously fused silica is fused by heating it to its melting point. This can be done in crucible in a furnace.

Presently fused silica is already hot and fused.

Note: melted silica is probably a conductor, at least melted glass is a conductor.

The difference of calcium chloride and fused calcium chloride is the bond acting on their molecules. The fused calcium chloride is fused while the calcium chloride is not fused.

Fused silica is an engineering-quality, amorphous version of quartz.

Source: http://www.makeitfrom.com/material-data/?for=Fused-Silica-Fused-Quartz

The person is from ages 32-50 when the lambdoidal and sagittal sutures are fused but the coronal sutures are not fused.

Fused heterocylic compounds is a heterocylic compound (eg. Furan) fused with another ring which can be either a carbon ring (benzene) or can be fused with another heterocylic ring(Pyridine,Pyrrole,...etc). Fused heterocyclics can be either 2 fused rings,3 rings or more.

From the famous examples on fused heterocylic compounds:

-Heroin

-Indole

-Morphine

-Carbazole