摘要:
The present invention provides a method for preparing a nanoporous ultra-low dielectric thin film including a high-temperature ozone treatment and nanoporous ultra-low dielectric thin film prepared by the same method. The method includes preparing a mixture of an organic silicate matrix-containing solution and a reactive porogen-containing solution; coating the mixture on a substrate to form a thin film; and heating the thin film with an ozone treatment. The prepared nanoporous ultra-low dielectric thin film could have a dielectric constant of about 2.3 or less and a mechanical strength of about 10 GPa or more by improving a pore size and a distribution of pores in the thin film by performing an ozone treatment with high temperature and optimization of the ozone treatment temperature.
摘要:
There is provided a method of producing U3O8 powder having large surface area and small particle size by oxidizing defective UO2 pellets and manufacturing nuclear fuel pellets which are stable in a pore structure and high in density through the use of a mixture comprising UO2 powder and U3O8 powder. The method includes producing an U308 powder having a surface area of at least 1 m2/g by oxidizing defective UO2 pellets at a temperature of 300 to 370° C. in such a way that a maximum weight increase rate per 1 g of the UO2 pellets is up to 0.06 wt %/min; producing a mixed powder by mixing the U3O8 powder with an UO2 powder by 2 to 15 wt %; producing a compact by compression molding the mixed powder; and sintering the compact in a reducing gas atmosphere at a temperature of 1600 to 1800° C. In addition, a small amount of an Al-compound may be added to the oxidized U3O8 powder before the U3O8 powder is mixed with the UO2 powder. The additive such as Al is mixed with the U3O8 powder and then mixed with the UO2 powder to produce the pellets by a conventional production method. This ensures a stable pore structure, high density and a considerable increase in a crystal grain size.
摘要:
Provided are a method of controlling the compositional gradient and solubility of doped-additives at grain boundaries during sintering of a uranium-based oxide green pellet including the additives, and a method of manufacturing a sintered nuclear fuel pellet having a large grain size using the same. The grain boundary solubility of the doped-additives is maintained at a certain level by stepwise varying of an oxygen partial pressure during isothermal sintering of a uranium-based oxide green pellet including the additives. The method of manufacturing a sintered nuclear fuel pellet having a large grain size includes preparing additive mixed uranium oxide powder, forming an additive mixed uranium oxide green pellet using the mixed powder, heating the green pellet to a sintering temperature in a gas atmosphere having a low oxygen partial pressure, and sintering while a sintering gas atmosphere is changed to stepwise increase an oxygen partial pressure at the isothermal sintering temperature.
摘要:
The present invention relates to a high temperature proton-conducting polymer membrane, a preparation method thereof, a membrane-electrode assembly using the same and a fuel cell containing the same. More particularly, it relates to a proton-conducting polymer membrane enabling fuel cell operation under high temperature and normal pressure condition, wherein sulfoalkyl or sulfoaryl groups are introduced between layers of metal phosphate and cation exchange groups are present in side chains, a preparation method thereof and a membrane-electrode assembly using the proton exchange membrane and a fuel cell containing the same.
摘要:
Disclosed is a motor. The motor includes a rotor case, a ring member mounted on the rotor case and including an encoder on a bottom surface thereof extending outside of the rotor case, and an encoder sensor detecting speed information of the rotor case from the encoder such that the rotor case rotates at low speeds enabling a LightScribe operation.
摘要:
A motor device includes a base plate on which a motor for rotating a disk is disposed, a flexible printed circuit board disposed on the base plate and having a circuit pattern applying power to the motor, and a screw mounting portion provided with a ground pattern of the FPCB, mounted with a screw engaged to electrically connect the ground pattern to the base plate, and having a part on which solders are provided.
摘要:
A disk chucking device and a disk driving device having the same are disclosed. The disk chucking device may include: a chuck base, on which a boss is formed; chuck chips inserted in the chuck base in a manner such that the chuck chips protrude out from the chuck base; an elastic member, which elastically supports a pair of adjacent chuck chips towards an outer side of the chuck base; and a protrusion portion, which is formed on a bottom of the boss, and which supports the elastic member. The disk chucking device can improve the environment of the elastic members that support the chuck chips, to improve the alignment between the rotation centers of the disk and the chuck base.
摘要:
An optical disk apparatus includes a printed circuit board; a stator fixed on the printed circuit board; a rotor configured to receive an optical disk thereon, the rotor being rotated by an electromagnetic interaction with the stator; and a sensing part fixed on the printed circuit board and sensing a rotation of the optical disk. Here, the sensing part includes a sensor; a terminal connecting the sensor with the printed circuit board electrically; and a plastic mold fixing the terminal thereto. The optical disk apparatus has a reduced number of components to allow reduced production costs, and has a simple manufacturing process to allow reduced production times and defect rate.