A terahertz material for emission reduction and fuel saving of gasoline vehicles and its preparation method and application, includes the following raw materials in parts by weight: 2035 SiO.sub.x, 315 Al.sub.2O.sub.3, 2545 SiO.sub.2, 1525 Fe.sub.2O.sub.3, 2040 ochre, 0.52 barium tungstate, 1525 CaCO.sub.3, wherein a preparation method includes: mixing the component raw materials according to the above ratio; after crushing, performing heating to 6001,200 C. in an oxygen-free environment, maintaining the temperature for 38 hours, and then performing crushing for the second time; and performing enhancement processing with terahertz irradiation rays at 10 mW to 100 W for 5 seconds to 1 hour to obtain a terahertz material, wherein the terahertz material improves combustion efficiency by increasing the molecular activity of gasoline and air participating in combustion work and reducing molecular groups, and has the effects of emission reduction, energy saving and improving power.

The present invention provides a high-energy-density slurry fuel, a preparation method, and an application. The high-energy-density slurry fuel comprises the following components in percentage by mass: 3%-40% of aluminum-based-metal hydride composite fuel; 53.6%-96% of high-density liquid hydrocarbon fuel; 0.2%-2% of anti-settling agent; and 0.2%-5% of other performance regulators, wherein an aluminum-based-metal hydride is a composite material that disperses and distributes a metal hydride inside aluminum powder particles. The high-energy-density slurry fuel may be used as a fuel for an engine such as a ramjet engine or a rocket engine. Compared with the existing liquid fuel, the present high-energy-density slurry fuel has the characteristics of high density (.sub.20 C.>0.9 g/cm3), high heat value (greater than 38 MJ/kg), rapid ignition, and efficient combustion; and compared with the existing slurry fuel, the present high-energy-density slurry fuel has the advantages of rapid ignition, efficient combustion, and no residue or less residue in combustion products.

The present disclosure is directed to fuel compositions comprising a polar based continuous phase comprising a liquid ammonia with a concentration greater than about 81% by v/v of total polar phase; and a non-polar based discontinuous phase comprising one or more of a frozen hydrocarbon, a viscous liquid hydrocarbon, and a liquefied volatile hydrocarbon, wherein the fuel composition has a droplet size ranging from about 100 nm to about 250 m. Further, the disclosure provides for systems and methods for using the fuel compositions.