Abstract: A method for producing mesoporous nanoscale iron-containing metal particles includes the steps of: adding dropwise a reducing agent into an iron salt containing aqueous solution under a condition that the molar ratio of the reducing agent to the iron salt ranges from 6 to 10 times the stoichiometric ratio of the reducing agent to the iron salt to produce mesoporous nanoscale iron-containing metal particles; separating the mesoporous nanoscale iron-containing metal particles from the aqueous solution; and drying the mesoporous nanoscale iron-containing metal particles.

Abstract: A method for treating a body of a polluted porous medium, includes the steps of: preparing a reactive solution containing nanoparticles; injecting the reactive solution into the body of the polluted porous medium so as to decompose pollutants in the polluted porous medium by reacting the nanoparticles with the pollutants; and applying an electric field to the body of the polluted porous medium so as to enhance transporting effect of the nanoparticles in the body of the polluted porous medium.

Abstract: An automatic homing rotary hinge, which includes a pivotal rod, a spring slipped onto the pivotal rod, an assembly board, and a friction portion. The friction portion has a spacer, a baffle, a push gasket, and a skidproof gasket, which are assembled on the pivotal rod in order. Static balance is achieved between a torsion of the spring, the weight of an object and an elastic pressing force and a friction force of the friction portion to arbitrarily position the included angle between two objects. The spring is used to restore the original included angle between the two objects.