摘要:
A process for producing pyromellitic acid which comprises oxidizing 2,4,5-trimethylbenzaldehyde and/or its oxidized derivative in the presence of a catalyst containing iron, manganese and bromine, or additionally containing zirconium or cerium continuously or semi-continuously using aqueous acetic acid solvent and 0.05-2% by weight of bromide ion. The catalyst used in the present invention has high activity, and the catalyst solution has low corrosive because the reaction is performed at low bromide concentration by using a solvent of aqueous acetic acid. So pyromellitic acid is produced industrially advantageously in high yield continuously or semi-continuously which has been a major difficulty up to now.
摘要:
The S/N ratio is improved for recording data to grooves (2-1,2-2) of an optical disc so that as much information as possible can be recorded at the lowest possible frequency band. An optical disc using wobble patterns to record different information has a first groove (2-1) having a first wobble pattern (22) in which one wobble period has a sharp rising edge and a gradual falling edge; and a second groove (2-2) having a second wobble pattern (24) in which one wobble period has a gradual rising edge and a sharp falling edge. Each of the first and the second wobble pattern is represented by a first fundamental and a second harmonic of a Fourier series. The polarity of the second harmonic, which is an even harmonic, of the second wobble pattern is opposite that of the first wobble pattern. A method for manufacturing this optical disc is also provided.
摘要:
An airbag comprises an airbag body, and a wrapping member made tearable for preventing the airbag body from returning to its unfolded state. The airbag body is folded and housed on the peripheral edge of an opening on the inner side of a car body, and is folded up into a rod shape so that it may be inflated when an inflating gas flows thereinto so as to cover the opening. The wrapping member is made flexible and long and is wrapped on the outer periphery of the folded airbag body substantially all along the length of the same, so that it may extend obliquely to the axial direction of the airbag body folded up into the rod-like shape. Moreover, the airbag is restrained in its proper folded state substantially all along its length by a simple wrapping operation.
摘要:
An optical disc recorder and/or player using as a recording medium an optical disc having a plurality of recording layers formed one over another includes an optical pickup having a photodetector to direct a light beam towards any one of the plurality of recording layers and detect a return light beam from a recording layer, and an identifier to compare an output signal from the photodetector with a predetermined reference value and identify, based on a comparison result, which one of the plurality of recording layers formed in the optical disc has focused thereon the light beam from the optical pickup.
摘要:
Provided is an active material for a non-aqueous secondary battery having improved safety while maintaining the capacity and the cycle characteristic, a process for producing the same, and a non-aqueous secondary battery using the same. The active material can be doped/undoped with an alkali metal ion; the active material is a compound particle comprising three or more of constituting elements, and contains an element A selected from Li, Na, K, Mg, Ca, Sr, Ba, B, Al, Ga, In, Si, Zr, Sn, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ag and Zn as one of the constituting elements; the particle has a region where the concentration of element A is decreasing continuously in the direction of from the particle surface to the particle core; and the ratio (d/D) of the mean width (d) of this region towards the depth direction to the mean radius (D) of the particle is 0.001
摘要:
A method for embedding digital watermark data in digital data contents includes the steps of obtaining a frequency coefficient of block data of digital data contents, obtaining a complexity of the block data, obtaining an amount of transformation of the frequency coefficient from the complexity and the digital watermark data, and embedding the digital watermark data by transforming the frequency coefficient. In addition, a method for reading digital watermark data includes the steps of calculating a probability of reading ‘1’ or ‘0’ in a read bit sequence by using a test method on the basis of binary distribution, determining the presence or absence of digital watermark data according to the probability, and reconstituting digital watermark data. Another method includes the steps of performing soft decision in code theory by assigning weights to the digital watermark sequence with a weighting function, and reconstituting digital watermark data.
摘要:
An optical disc having a protection layer for protecting a recording layer located farther from a substrate and having a first recording layer and a second recording layer stacked on one side of the substrate, wherein the reflectance of one of the first and second recording layers is made higher than the reflectance of the other recording layer, and a reproducing device which uses this optical disc. The reproducing device casts a light beam emitted from a single light source onto the first recording layer or the second recording layer via a single objective lens, discriminates which of the first recording layer and the second recording layer the light beam emitted from the light source is cast on, on the basis of the result of detection of a reflected beam from the first recording layer or the second recording layer, moves the objective lens in a direction parallel to the optical axis of the objective lens on the basis of the result of discrimination, and condenses the light beam on the first recording layer or the second recording layer so as to carry out reproduction of information.
摘要:
Platy potassium titanate having a mean major diameter of 1-100 &mgr;m and a mean aspect ratio of 3-500 and obtainable by subjecting magnesium or lithium potassium titanate to an acid treatment to thereby prepare platy titanate, immersing the platy titanate in a potassium hydroxide solution and then subjecting it to calcination.
摘要:
A radiation image storage panel comprises at least a substrate and a phosphor layer overlaid upon the substrate. The phosphor layer contains a binder, a phosphor, and at least one kind of organic phosphorus compound represented by Formula (1): (R)nPO(OM)3−n (1) in which R represents an alkyl group, an aryl group, or a heterocyclic group, which may be optionally substituted by a substituent; M represents a hydrogen atom, an alkali metal, or —N+(R1)4, where R1 represents an alkyl group having at most two carbon atoms; and n represents an integral number of 1 or 2. The radiation image storage panel exhibits enhanced dispersibility of phosphor particles and a high sensitivity and yields little noise.
摘要:
An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits. The rotation of the optical recording medium is controlled by the wobbled signals detected from the groove and the position on the optical recording medium of the recording signal is detected by the pit signal detected from the pits.