摘要:
A pulse width modulation amplifier circuit includes a comparator which receives an analog signal and generates first and second analog signals having a phase difference of 180 degrees. A phase shifting circuit produces first and second triangular wave carrier signals so as to establish therebetween a phase difference of approximately 90 degrees. First and second pulse width modulation amplifiers, having output terminals connected to a load, pulse width modulate the first and second triangular wave carrier signals with said first and second analog signals, respectively, and amplify resultant pulse width signals.
摘要:
An optical system having a grating lens assembly including a first grating lens which diffracts rays of a beam incident thereupon so as to provide non-parallel diffraction rays and a second grating lens which converges the non-parallel diffraction rays at a predetermined point substantially without aberration.
摘要:
The acoustic transmission characteristics of a sound field, such as in the passenger compartment of a vehicle, are measured by placing microphones at the positions of ears of a dummy mannequin having a sound absorbing characteristic similar to that of a clothed adult human. The transmission characteristics are then corrected, such as with an automatic graphic equalizer, to provide optimized listening conditions inside the sound field for an actual listener. The use of the invention results in a listener's perception of completely natural sound.
摘要:
A compound of the formula: ##STR1## wherein R.sup.1 is lower alkyl,R.sup.3 is hydrogen, halogen or ar(lower)alkoxy, andR is lower alkanoyl, nitroso, amino, carboxy, esterified carboxy, carbamoyl, hydroxycarbamoyl, haloformyl, aminomethyleneamino which may be substituted with cyano or lower alkyl, iminomethylamino which may be substituted with cyano or lower alkyl, or a group of the formula: --A--R.sup.2 in which A is lower alkylene andR.sup.2 is di(lower) alkylamino, cyano, lower alkoxy, N-containing heterocyclic group which may have suitable substituent(s), lower alkynyloxy, lower alkenyloxy, lower alkylthio, amino(lower)alkylthio, lower alkylsulfinyl, lower alkylsulfonyl, carboxy, esterified carboxy, carbamoyl, hydroxycarbamoyl, hydroxy, lower alkanoyloxy, heterocyclicamino(lower)alkylthio having two oxo groups, hydrogen or a group of the formula: ##STR2## in which R.sup.4, R.sup.5 and R.sup.6 are each lower alkyl andX is an acid residue,and pharmaceutically acceptable salts thereof. pa The compounds are useful as anti ulcer agents.
摘要:
Anti-allergic quinazolinone derivatives are disclosed which have the formula ##STR1## wherein R.sup.3 is hydrogen or lower alkyl and A is lower alkylene.
摘要:
An automatic graphic equalizer for a sound system has circuitry for measuring the effect of the physical environment receiving a sound on the frequency characteristics of the sound, and for adjusting the characteristics of a graphic equalizer to compensate for distortions in the desired flat frequency response caused by the physical environment. The circuitry includes a pink noise generator supplying pink noise to the graphic equalizer during an initialization operation, the graphic equalizer being controlled by a controller to present a flat frequency characteristic. The equalizer output is sent to a speaker which supplies the pink noise as a sound signal to the selected environment. A microphone picks up the sound in the selected environment and converts it to an electrical signal which is supplied through an ALC amplifier to a frequency-variable band-pass filter to detect the signal level in each of the equalizer frequency bands. The level signals are smoothed in a level detector and digitized to be input to the controller which readjusts the graphic equalizer to compensate for distortions in the desired flat frequency response caused by the selected environment.
摘要:
The invention relates to novel intermediates for preparing novel cephem compounds of high antimicrobial activity, the intermediates being of the formula: ##STR1## wherein A is lower alkylene which may have an oxo group;R.sup.3 is carboxy, protected carboxy, lower alkyl, lower alkenyl, hydroxy(lower)alkyl, phenyl(lower)alkyl or aryl; andR.sup.7a is hydrogen or a mercapto-protective group, or a salt thereof.
摘要:
The invention relates to novel tropone derivatives, of antiinflammatory, analgesic and antirheumatic activity, of the formula: ##STR1## wherein R.sup.1 is hydrogen or lower alkyl,R.sup.2 is hydrogen, hydroxy, halogen, lower alkyl, or lower alkoxy, andR.sup.3 is hydrogen or acyl,and pharmaceutically acceptable salts thereof.