An optical window is provided and includes a core layer, a cladding layer and an electromagnetic interference (EMI) layer interposed between the core and cladding layers.

An optical window is provided and includes a core layer, a cladding layer and an electromagnetic interference (EMI) layer interposed between the core and cladding layers.

An MA-M.sub.2T spinel solid solution-reinforced magnesium oxide-based ceramic foam filter and a preparation therefor. The preparation method comprising: 1) preparing a ceramic slurry having a solid content of 60%-70% by dosing 15%-25% by mass of a nanometer alumina sol, 0.8%-1.5% by mass of a rheological agent, and the balance magnesium oxide ceramic powder comprising a nanometer titanium oxide sintering aid, and then adding deionized water and ball milling to mix until uniform, and then vacuum degassing the mixture; 2) soaking a polyurethane foam plastic template into the ceramic slurry, squeezing by a roller press the polyurethane foam plastic template to remove redundant slurry therein to make a biscuit, and drying the biscuit by heating it to 80 C.-120 C.; 3) putting the dried biscuit into a sintering furnace, elevating the temperature to 1400 C.-1600 C. and performing a high temperature sintering, cooling to the room temperature with the furnace to obtain the magnesium oxide-based ceramic foam filter.

An MA-M.sub.2T spinel solid solution-reinforced magnesium oxide-based ceramic foam filter and a preparation therefor. The preparation method comprising: 1) preparing a ceramic slurry having a solid content of 60%-70% by dosing 15%-25% by mass of a nanometer alumina sol, 0.8%-1.5% by mass of a rheological agent, and the balance magnesium oxide ceramic powder comprising a nanometer titanium oxide sintering aid, and then adding deionized water and ball milling to mix until uniform, and then vacuum degassing the mixture; 2) soaking a polyurethane foam plastic template into the ceramic slurry, squeezing by a roller press the polyurethane foam plastic template to remove redundant slurry therein to make a biscuit, and drying the biscuit by heating it to 80 C.-120 C.; 3) putting the dried biscuit into a sintering furnace, elevating the temperature to 1400 C.-1600 C. and performing a high temperature sintering, cooling to the room temperature with the furnace to obtain the magnesium oxide-based ceramic foam filter.

The present invention provides A magnesium oxide whisker in-situ formed MA spinel-reinforced magnesium oxide-based ceramic foam filter and a method for preparing the same. The method comprising: 1) preparing a ceramic slurry having a solid content of 60%-70% by dosing 15%-25% by mass of a nanometer alumina sol, 0.8%-1.5% by mass of a rheological agent, and the balance magnesium oxide ceramic powder comprising magnesium oxide whiskers, and then adding deionized water and ball milling to mix until uniform, and then vacuum degassing the mixture; 2) soaking a polyurethane foam template into the ceramic slurry, squeezing by a roller press the polyurethane foam template to remove redundant slurry therein to make a biscuit, and drying the biscuit by heating it to 80 C.-1200 C.; 3) putting the dried biscuit into a sintering furnace, elevating the temperature to 1400 C.-1600 C. and performing a high temperature sintering, cooling to the room temperature with the furnace to obtain the magnesium oxide-based ceramic foam filter.

A spinel-reinforced magnesium oxide-based foam ceramic filter that is obtained by by coating onto a polyurethane foam carrier a slurry of light calcined magnesium oxide-based ceramic comprising a nanometer lanthanum oxide sintering aid, and then drying and sintering. A method for preparing the foam ceramic filter comprising: 1) preparing a ceramic slurry having a solid content of 60%-70% by dosing 15%-25% by mass of a nanometer alumina sol, 0.8%-1.5% by mass of a rheological agent, and the balance magnesium oxide ceramic powder comprising a nanometer lanthanum oxide sintering aid, and then adding absolute ethanol and ball milling to mix until uniform; 2) soaking a polyurethane foam template into the ceramic slurry, squeezing by a roller press the polyurethane foam template to remove redundant slurry therein to make a biscuit, and then removing the ethanol solvent in a ventilation chamber at a temperature of 40 C.-50 C. to dry the biscuit; 3) putting the dried biscuit into a sintering furnace, elevating the temperature to 1350 C.-1550 C. and performing a high temperature sintering, cooling to the room temperature with the furnace to obtain the magnesium oxide-based ceramic foam filter.

A spinel-reinforced magnesium oxide-based foam ceramic filter that is obtained by by coating onto a polyurethane foam carrier a slurry of light calcined magnesium oxide-based ceramic comprising a nanometer lanthanum oxide sintering aid, and then drying and sintering. A method for preparing the foam ceramic filter comprising: 1) preparing a ceramic slurry having a solid content of 60%-70% by dosing 15%-25% by mass of a nanometer alumina sol, 0.8%-1.5% by mass of a rheological agent, and the balance magnesium oxide ceramic powder comprising a nanometer lanthanum oxide sintering aid, and then adding absolute ethanol and ball milling to mix until uniform; 2) soaking a polyurethane foam template into the ceramic slurry, squeezing by a roller press the polyurethane foam template to remove redundant slurry therein to make a biscuit, and then removing the ethanol solvent in a ventilation chamber at a temperature of 40 C.-50 C. to dry the biscuit; 3) putting the dried biscuit into a sintering furnace, elevating the temperature to 1350 C.-1550 C. and performing a high temperature sintering, cooling to the room temperature with the furnace to obtain the magnesium oxide-based ceramic foam filter.

A spinel-reinforced magnesium oxide-based foam ceramic filter that is obtained by by coating onto a polyurethane foam carrier a slurry of light calcined magnesium oxide-based ceramic comprising a nanometer lanthanum oxide sintering aid, and then drying and sintering. A method for preparing the foam ceramic filter comprising: 1) preparing a ceramic slurry having a solid content of 60%-70% by dosing 15%-25% by mass of a nanometer alumina sol, 0.8%-1.5% by mass of a rheological agent, and the balance magnesium oxide ceramic powder comprising a nanometer lanthanum oxide sintering aid, and then adding absolute ethanol and ball milling to mix until uniform; 2) soaking a polyurethane foam template into the ceramic slurry, squeezing by a roller press the polyurethane foam template to remove redundant slurry therein to make a biscuit, and then removing the ethanol solvent in a ventilation chamber at a temperature of 40 C.-50 C. to dry the biscuit; 3) putting the dried biscuit into a sintering furnace, elevating the temperature to 1350 C.-1550 C. and performing a high temperature sintering, cooling to the room temperature with the furnace to obtain the magnesium oxide-based ceramic foam filter.

The present application relates to a magnesium oxide based dielectric ceramics with ultrahigh dielectric breakdown strength and a preparation method thereof. The composition of the magnesium oxide based dielectric ceramic material comprises: (1x)MgO-xAl.sub.2O.sub.3, wherein 0<x0.12 and x is a mole percentage. The material has a specific composite structure with magnesium aluminate spinel acting as a second phase surrounding a principal crystalline phase, MgO.

The present application relates to a magnesium oxide based dielectric ceramics with ultrahigh dielectric breakdown strength and a preparation method thereof. The composition of the magnesium oxide based dielectric ceramic material comprises: (1x)MgO-xAl.sub.2O.sub.3, wherein 0<x0.12 and x is a mole percentage. The material has a specific composite structure with magnesium aluminate spinel acting as a second phase surrounding a principal crystalline phase, MgO.