Abstract: This disclosure relates to slow- and controlled-release fertilizers (S-CRF), and more particularly to a microelement amino acid chelate-urea formaldehyde (UF) slow-release fertilizer and a method for preparing the same by reactive extrusion. The microelement amino acid chelate-UF slow-release fertilizer includes a biodegradable UF polymer and a microelement amino acid chelate. The macromolecular chains of the biodegradable UF polymer interpenetrate in the cross-linked network structure of the chelate, so as to form a polymer composite with a semi-interpenetrating network structure.

Abstract: A device for determining degradation rate of biodegradable polymers in soil, including a micro compressed air pump, a first CO2 absorption vessel filled with dry soda lime or an aqueous strong alkali solution, a CO2 indicator vessel filled with a barium hydroxide solution, a hollow leaching device, a second CO2 absorption vessel and a third CO2 absorption vessel connected in sequence through connecting pipes. A top of the hollow leaching device is provided with an end cover. An external water distributor filled with a leaching solution and a mechanical stirring device is arranged above the end cover. The external water distributor is in communication with an inner cavity of the hollow leaching device through a pipeline. A stirring shaft of the mechanical stirring device extends into the inner cavity. A stirring shaft is provided with a stirring paddle.

Abstract: An injection mold for a high-aspect-ratio double-layer cylindrical plastic part and a molding method using the same. The injection mold includes a support base plate. A movable mold fixing frame and a movable mold base plate are arranged at the middle of a lower surface of the support base plate through positioning screws. A lower core mold is matchingly provided at a center of an upper surface of the support base plate, and is provided with a lower semicircular cavity for accommodating an outer die barrel. One side of the lower semicircular cavity is open, and the other side is provided with a first end wall which is provided with a lower semicircular notch for an inner die rod to pass through. An upper surface of the lower core mold is provided with a positioning protrusion, a lower feeding groove, and a remaining groove.

Abstract: A gradient electrically conductive-uniform thermally conductive dual network structure-based electromagnetic shielding polymer composite with low reflection and high absorption and a preparation method thereof. The electromagnetic shielding polymer composite includes a gradient conductive carbon nanotube network with a vertically oriented cell structure and a uniformly thermally conductive hexagonal boron nitride/carbon nanotube network constructed by the hexagonal boron nitride dispersed uniformly in the carbon nanotube network and the gradient carbon nanotube network. The gradient electrically conductive carbon nanotube network and the uniformly thermally conductive hexagonal boron nitride/carbon nanotube network form a composite synergistic dual function network structure so as to make the electromagnetic shielding polymer composite have a low reflection and high absorption and excellent thermal conductivity.

Abstract: A method for continuously preparing graphene powder directly dispersed in an organic system, including: mixing an aqueous graphene oxide dispersion, an emulsifier and an oil-soluble monomer followed by pH adjustment and dispersing to obtain a pre-emulsified dispersion; subjecting the pre-emulsified dispersion to an emulsion polymerization reaction in the presence of an initiator; introducing a reducing agent to reduce graphene oxide; and subjecting the reaction mixture after emulsion polymerization to spray drying to obtain the graphene powder. Equipment used in the preparation method is also provided herein.