摘要:
The present invention relates to a novel method for preparing a catalyst for partial oxidation of methlybenzenes, comprising, (a) a step of preparing a solution or slurry of the compounds comprising tungsten (b) a step of supporting the solution or slurry obtained in the step (a) on inorganic carrier; (c) a step of drying the catalyst obtained in the step (b); and (d) a step of calcining the dried catalyst obtained in the step (c), characterized in that the ratio of the pore volume of inorganic carrier and the volume of the solution or slurry in the step (b) is 1:09˜1.1, and the catalyst provides superior aromatic aldehydes selectivity to those prepared by the conventional impregnation or heat evaporation method over a wide range of conversion rate.
摘要:
The present invention provides an apparatus and method for compensating for the variation of a gain spectrum attributable to the temperature variation of a fiber amplifier, and a long-wavelength band dispersion-compensating hybrid amplifier equipped with the gain spectrum compensating apparatus. The apparatus includes a DCF located between a first amplification stage and a second amplification stage to compensate for dispersion of an optical signal output from the first amplification stage and perform Raman amplification of the optical signal using input pumping light; at least one pumping light provision means for providing forward or backward pumping light to the DCF; first and second temperature detection means for detecting temperature variations of the first and second amplification stages, respectively; and control means for controlling intensity of the pumping light of the pumping light provision means according to the detected temperature variations.
摘要:
A reformer is disclosed for supplying a reformed gas containing hydrogen to a fuel cell. The reformer comprises a heat source; a preheating portion preheated by heat from the heat source; a pipe shaped reforming reaction unit; a carbon monoxide processing unit extending from the reforming reaction unit; and a rugged portion installed on an internal surface of the pipe shaped reforming reaction unit which is heated by the heat source. By using the rugged portion and the extended pipe design, the area heated by the heat source is increased and more heat is recovered, thereby improving thermal efficiency.
摘要:
Disclosed is a method for producing a transparent and homogenized polymeric sol of a calcium phosphate compound, containing apatite and having excellent wettability and bioactivity, according to a sol-gel synthesis, and a method for coating the polymeric sol on a metal implant, in which the polymeric sol is coated on the metal implant and then heat-treated to form a dense coated layer strongly bonded to the metal implant. The polymeric sol is obtained by process of preparing a calcium salt solution, containing calcium ethoxide dissolved in organic acid, and a phosphate solution, containing triethyl phosphite or triethyl phosphate dissolved in the organic acid, mixing the calcium salt solution with the phosphate solution to produce a mixed solution, and aging the mixed solution.
摘要:
The present invention relates to a lens driving device includes a lens receiving part with a lens disposed therein, having first and second extension parts formed at opposed sides in a predetermined interval from each other. The lens driving device also includes an actuator having a body between the first and second extension parts. The actuator body has first and second output members contacting the first and second extension parts of the lens receiving part at opposed ends thereof, and thereby expands, contracts and bends when power is applied. The lens driving device also includes a preload member compressing the first and second extension parts against the actuator body to maintain a status of pressed contact. The lens driving device further includes a guide part for guiding the movement of the lens receiving part in an optical axis direction.
摘要:
A photoresist coating apparatus and method for solving an edge bead problem occurring in photoresist coating. An edge bead is prevented from occurring by forming a solvent vapor layer from ionized solvent vapor on a wafer through the use of a magnetic field generator, spraying a liquid photoresist on the wafer, and controlling the liquid photoresist to not vaporize more at the edge of the wafer than towards the center thereof. A photoresist coating apparatus includes: a solvent ionizer supplying ionized solvent vapor; and a magnetic field generator forming a solvent vapor layer on a wafer from the ionized solvent vapor.
摘要:
The invention relates to a piezoelectric vibrator easily manufactured and mass-produced. The piezoelectric vibrator includes the piezoelectric bar having a plurality of piezoelectric plates alternately stacked and a plurality of vibration sectors divided vertically and horizontally with respect to the direction in which the piezoelectric plates are stacked. Electrode terminals are formed on each of surface regions of the piezoelectric plate, divided in a longitudinal direction thereof, and jump terminals corresponding to electrode terminals are formed on a surface of an adjacent one of the piezoelectric plates. On side surfaces of the piezoelectric plates, a plurality of side electrodes are formed, connecting the electrode terminals and the corresponding jump terminals to power the vibration sectors, by which a pair of the vibration sectors diagonally disposed from each other are simultaneously powered. The piezoelectric vibrator is small and easily manufactured and mass-produced with a simple structure.
摘要:
A piezoelectric ultrasonic motor includes a piezoelectric stator including a metal tube with an inner space and piezoelectric elements mounted on the outer circumference of the metal tube, a rotary shaft including a rotation bar inserted into the inner space of the metal tube, and a rotation member provided around the rotation bar in contact with the piezoelectric stator. The piezoelectric stator strains with an electric field applied thereto, and the rotation member rotates in response to the strain of the piezoelectric stator. A power transmission member is provided at one portion of the rotation bar to transmit the rotation of the rotation member to an object to be transported. With face contact the motor achieves stable actuation together with enhanced force and sufficient strain, and a flexibility to be applied to various apparatuses such as a camera module.
摘要:
The present invention relates to a ceramic tube type ultrasonic motor having a stator including a tube-type elastic body that is formed of a ceramic material; and a plurality of piezoelectric diaphragms that are attached on the outer peripheral surface of the elastic body in a longitudinal direction thereof and to which voltages having a phase difference are respectively applied and a rotor that is rotated by the friction with the elastic body flexurally vibrating due to the voltages applied to the plurality of piezoelectric diaphragms.
摘要:
A structure capable of automatically supporting a nodal point of a piezoelectric stator is provided. The structure includes a piezoelectric stator constructed of at least one piezoelectric element and having at least one nodal point; at least one elastic member elastically contacting the piezoelectric stator via the piezoelectric element; a holder arranged around the piezoelectric stator and mounted with the elastic member; and a power supply for applying an electric field to the piezoelectric element via the elastic member. The elastic member automatically locates and contacts the nodal point of the piezoelectric stator owing to the strain of the piezoelectric stator when the electric field is applied to the piezoelectric element. As the nodal point of the piezoelectric stator is correctly supported, oscillation efficiency of the piezoelectric stator is maximized.