1. An in situ system of manufacturing nanoparticles having a core-shell structure, the system comprising:
a nanoparticle generating unit configured to generate the nanoparticles in a reaction chamber;
a nanoparticle coating unit configured to receive the nanoparticles serving as a core material from a process passage of a coating chamber connected to the nanoparticle generating unit, supply a carrier gas and a reactive gas serving as a source of a shell material into the process passage of the coating chamber, and coat the nanoparticles moving in the process passage of the coating chamber with the shell material in a state in which a vacuum pump is operated; and
a core-shell nanoparticle collecting unit configured to collect the nanoparticles having the core-shell structure coated with the shell material in the nanoparticle coating unit,
wherein the units are connected to link and continuously process generation of the nanoparticles and a coating and collecting process performed by the nanoparticle generating unit, the nanoparticle coating unit, and the core-shell nanoparticle collecting unit, and
the nanoparticle coating unit has a speed adjustment member installed in the process passage of the coating chamber such that a moving speed of the nanoparticles is decreased and the reactive gas moves to overtake the foregoing nanoparticles.
2. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 1, wherein the speed adjustment member is formed of a porous material or in a grid structure.
3. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 2, wherein a plurality of speed adjustment members are installed in a longitudinal direction of the process passage at predetermined intervals, and
the moving speed of the nanoparticles is decreased due to flow resistance or collision when the nanoparticles pass through the speed adjustment member.
4. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 1, wherein a supply period of the reactive gas is set to correspond to a coating thickness of the shell material coated on the nanoparticles.
5. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 4, wherein a first precursor and a second precursor are alternately supplied as the reactive gas, and
a discharge time for discharging a reactant or byproduct generated in the coating chamber is set whenever one of the first and second precursors is supplied.
6. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 4, wherein the carrier gas is argon (Ar) serving as an inert gas, and
TMA (trimethylaluminum) serving as an aluminum source and H2O serving as an oxygen source are used as the reactive gas when an aluminum oxide (Al2O3) thin film is coated as the shell material.
7. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 1, wherein the nanoparticle generating unit comprises a fluid supply pump configured to supply a precursor in a liquid phase serving as a spray sample of the nanoparticles, a gas supply source configured to supply the carrier gas and the reactive gas, and a low temperature plasma generator configured to generate low temperature plasma according to a radio frequency inductively coupled plasma (ICP) method.
8. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 7, wherein the low temperature plasma generator comprises an RF matching box configured to match impedance of the reaction chamber using a direct current high voltage supply unit, an electrospray nozzle, and a radio frequency.
9. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 1, wherein the core-shell nanoparticle collecting unit comprises at least one of a cyclone collector, an electrostatic collector, and a particle collector.
10. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 9, wherein the electrostatic collector comprises an electrode member constituted by a high voltage electrode installed at a collecting container and a ground electrode, and an alternating current high voltage supply unit configured to supply an alternating current high voltage to the high voltage electrode, and
the ground electrode comprises a plurality of disk-shaped conductive plates installed in an axial direction of a support section, and a periphery of the conductive plate has a sharp serration shape.
11. The in situ system of manufacturing the nanoparticles having the core-shell structure according to claim 9, wherein the particle collector comprises a separating container connected to the electrostatic collector, a storage container installed to be in communication with the separating container and configured to finally collect and store the core-shell nanoparticles, and a plurality of grids installed in the separating container to guide the nanoparticles having the core-shell structure to the storage container.
12. An in situ method of manufacturing nanoparticles having a core-shell structure, the method comprising:
generating low pressure plasma in a reaction chamber, electrospraying a spray sample of nanoparticles into the reaction chamber, and supplying a carrier gas and a reactive gas to generate nanoparticles;
supplying the nanoparticles and the carrier gas, and the reactive gas serving as a source of a shell material into a process passage of a coating chamber;
coating the nanoparticles with the shell material by relatively rapidly moving the carrier gas supplied into the process passage and the reactive gas serving as the source of the shell material more than the nanoparticles as a moving speed of the nanoparticles supplied into the process passage of the coating chamber is decreased by a speed adjustment member; and
collecting the nanoparticles having the core-shell structure coated with the shell material.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A fixed codebook searching apparatus, comprising:
a convolution operator, implemented by at least one processor, that convolves an impulse response of a perceptually weighted synthesis filter with an impulse response vector that has values at negative times, to generate a second impulse response vector that has values at negative times;
a matrix generator, implemented by at least one processor, that generates a Toeplitz-type convolution matrix using the second impulse response vector generated by the convolution operator; and
a searcher, implemented by at least one processor, that performs a codebook search by maximizing a term using the Toeplitz-type convolution matrix,
wherein energy of components of the second impulse response vector at negative times is smaller than the energy of components at non-negative times.
2. A fixed codebook searching method, comprising:
convoluting an impulse response of a perceptually weighted synthesis filter with an impulse response vector that has values at negative times, to generate a second impulse response vector that has values at negative times;
generating a Toeplitz-type convolution matrix using the second impulse response vector; and
performing a codebook search by maximizing a term using the Toeplitz-type convolution matrix,
wherein energy of components of the second impulse response vector at negative times is smaller than the energy of components at non-negative times.