The present invention is a fly ash filler or filler blend having a particle size distribution with at least three modes that can be combined with a polymer at higher filler loadings to produce a filled polymer for polymer composites that, in many cases, can produce improved mechanical properties for the polymer composites over polymer composites using conventional fillers. A method comprises downloading content to a special purpose virtual machine and then storing the downloaded content at a location, where the location is only accessible via the special purpose virtual machine. A bias input terminal of a differential amplifier is pulled up according to an output of the source-grounded amplifier till the voltage of the second power supply rises, whereby an output of the laser driving circuit block is suppressed. Each constant-current feed unit is built in the submarine feed branching device.