摘要:
There is disclosed a process for producing an aromatic hydroxylic compound by acid decomposition of a hydroperoxide having the general formula (I) ##STR1## wherein Ar represents an aromatic hydrocarbon group having a valence of n; and n represents an integer of 1 or 2, in the presence of an acid catalyst, thereby to provide an aromatic hydroxylic compound having the general formula (II)Ar--(OH)n (II)wherein Ar and n are the same as above defined, characterized in that tetrafluoroboric acid, hexafluorosilicic acid or hexafluorophosphoric acid is used as the acid catalyst. According to this process, the aromatic hydroxylic compound is obtained in a high yield while the by-production of hydroxyacetone is effectively suppressed. In paricular, a more effective suppression of by-production of hydroxyacetone and a higher yield of the target compound can be achieved by carrying out the acid decomposition reaction in two stages wherein the first stage of the reaction is carried out in the first reactor at a temperature of 50.degree.-95.degree. C., the resultant reaction mixture is sent to the second reactor, and the second stage of the reaction is then carried out in the second reactor at a temperature of 80.degree.-120.degree. C.
摘要:
An object of the present invention is to achieve reductions in size and costs of a vehicle-mounted motor driving control board in a configuration which allows the redundancy of a power supply to be ensured. The vehicle-mounted motor driving control board is formed by one printed circuit board on which are formed two inverter driving circuits for driving two inverter circuits for three-phase motors, and a voltage step-up/step-down driving circuit for driving a voltage step-up/step-down circuit for supplying electric power to the inverter circuits. The vehicle-mounted motor driving control board further includes a first power supply circuit for supplying electric power to part of constituent circuits constituting the voltage step-up/step-down driving circuit and the two inverter driving circuits, and a second power supply circuit for supplying electric power to the remainder of the constituent circuits in the voltage step-up/step-down driving circuit and the two inverter driving circuits.
摘要:
A process for the production of lower olefins by dehydrating lower alcohols having 2 to 4 carbon atoms which comprises using a .gamma.-alumina catalyst containing 0.3% by weight or less of impurities in total excluding SiO.sub.2, the impurities including 0.2% by weight or less of sulfur content calculated in terms of SO.sub.4 - and 0.05% by weight or less of sodium content calculated in terms of Na.sub.2 O, and/or a process for the production of lower olefins by dehydrating lower alcohols having 2 to 4 carbon atoms that comprises using a .gamma.-alumina catalyst which contains 0.5 to 5% by weight of SiO.sub.2.According to the process of the present invention, lower olefins can be produced from lower alcohols with high yield and high selectivity for a prolonged period of time without reducing the catalytic activity.
摘要:
Propylene can be prepared in high yield and selectivity by dehydrating isopropanol in the presence of a .gamma.-alumina catalyst having a mean pore diameter of from 30 to 150 .ANG. with a standard deviation (.sigma..sub.n) of from 10 to 40 .ANG. based on statistic calculation from pore diameter and pore volume.
摘要:
A power module includes a first semiconductor device having a collector terminal and an emitter terminal which extend outwardly from a molded resin, wherein at least one of the collector and emitter terminals is a bilaterally extending terminal extending outwardly from two opposite surfaces of the molded resin, and a second semiconductor device having the same construction as the first semiconductor device. The bilaterally extending terminal of the first semiconductor device is connected to a bilaterally extending terminal of the second semiconductor device.
摘要:
This invention provides novel pyrimidines or their pharmaceutically acceptable salts thereof and process for preparation thereof. The novel compounds are useful for neurological diseases of the peripheral and central nervous systems of animals.
摘要:
A semiconductor device includes a semiconductor element having a gate and controlled with a gate voltage, a gate drive circuit which controls the gate voltage, an electrode connected to the semiconductor element, a principal current in the semiconductor element flowing through the electrode, a temperature sensing part which senses the temperature of the electrode, a generation section which generates, on the basis of the temperature sensed by the temperature sensing part, a first control signal for giving a maximum amount of energization to the semiconductor element in such a range that the temperature of the electrode does not exceed a predetermined temperature, and a comparison section which compares the first control signal and a second control signal transmitted from the outside for the purpose of controlling the gate voltage, and selects a selective control signal which is one of the control signals with which the temperature of the electrode can be limited. The gate drive circuit controls the gate voltage according to the selective control signal.
摘要:
An object of the present invention is to achieve reductions in size and costs of a vehicle-mounted motor driving control board in a configuration which allows the redundancy of a power supply to be ensured. The vehicle-mounted motor driving control board is formed by one printed circuit board on which are formed two inverter driving circuits for driving two inverter circuits for three-phase motors, and a voltage step-up/step-down driving circuit for driving a voltage step-up/step-down circuit for supplying electric power to the inverter circuits. The vehicle-mounted motor driving control board further includes a first power supply circuit for supplying electric power to part of constituent circuits constituting the voltage step-up/step-down driving circuit and the two inverter driving circuits, and a second power supply circuit for supplying electric power to the remainder of the constituent circuits in the voltage step-up/step-down driving circuit and the two inverter driving circuits.
摘要:
A semiconductor device includes a semiconductor element having a gate and controlled with a gate voltage, a gate drive circuit which controls the gate voltage, an electrode connected to the semiconductor element, a principal current in the semiconductor element flowing through the electrode, a temperature sensing part which senses the temperature of the electrode, a generation section which generates, on the basis of the temperature sensed by the temperature sensing part, a first control signal for giving a maximum amount of energization to the semiconductor element in such a range that the temperature of the electrode does not exceed a predetermined temperature, and a comparison section which compares the first control signal and a second control signal transmitted from the outside for the purpose of controlling the gate voltage, and selects a selective control signal which is one of the control signals with which the temperature of the electrode can be limited. The gate drive circuit controls the gate voltage according to the selective control signal.
摘要:
A power module includes a first semiconductor device having a collector terminal and an emitter terminal which extend outwardly from a molded resin, wherein at least one of the collector and emitter terminals is a bilaterally extending terminal extending outwardly from two opposite surfaces of the molded resin, and a second semiconductor device having the same construction as the first semiconductor device. The bilaterally extending terminal of the first semiconductor device is connected to a bilaterally extending terminal of the second semiconductor device.