39results about How to "Flexible and adjustable frequency" patented technology

The invention relates to chiral manganese oxide nanoparticles as well as a preparation method and application thereof, and relates to the technical field of material chemistry. According to the chiral manganese oxide nano particle, a manganese precursor, tartaric acid and a reducing agent react under the alkaline condition to obtain the chiral manganese oxide nano particle; and the tartaric acid is L-tartaric acid or D-tartaric acid. The chiral manganese oxide nanoparticles have chiral optical activity at 300-900nm, the preparation method is simple, the application is wide, and the prepared manganese oxide nanoparticles have important significance in promoting the development of the fields of optics, life science, medicine and the like.

The invention provides an ultra-high-order harmonic compensation control method, which is applied to an ultra-high-order harmonic compensation device, the device comprises an ultra-high-order harmonic source connected to a power grid, and the method comprises the following steps: S101, detecting ultra-high-order harmonics at a common connection point of the power grid, judging whether compensation is needed or not based on a detection result, if compensation is not needed, locking the ultra-high-order harmonic source, and if compensation is not needed, locking the ultra-high-order harmonic source; if compensation is needed, executing the next step; s102, determining a carrier angular frequency according to the detected ultra-high-order harmonics, and assigning initial values to a carrier phase, a direct current side voltage amplitude and a modulation ratio; s103, the carrier phase, the modulation ratio and the direct current side voltage amplitude are set until the carrier phase, the modulation ratio and the current side voltage amplitude which inhibit the ultra-high-order harmonic amplitude at the common connection point of the system side to the maximum degree are found; and S104, judging whether the ultra-high-order harmonic index at the common connection point meets the requirement or not, if so, enabling the ultra-high-order harmonic source to keep the operation parameters to continuously operate, and if not, returning to the step S103. According to the invention, compensation of specific-order ultra-high-order harmonics can be realized.

The invention relates to a floating charger capable of pulse charging, and belongs to the technical field of electronics. The floating charger comprises a process indication unit, a parallel discharging unit, a parallel charging unit, an interface unit, a pulse unit, a dual-selection ending unit, a load unit and a trickle resistor. A charging circuit difficult to damage is achieved by a few activepieces, the parallel charging unit, the parallel discharging unit, the interface unit and the pulse unit are combined to form pulse charging of which charging and discharging are simultaneously performed and charging time is larger than discharging time, a triode in the parallel charging unit is connected in a constant-current mode and is also in constant-current charging, two modes of ending after full charging of the battery and timely ending are arranged in measure, the switching is flexible and convenient, sound is reminded after ending, and a required trickle current is provided for a charged battery by the trickle resistor. After implementing the floating charger, the charging time and charging stopping time of the charged battery can be flexibly adjusted, different types of chargedbatteries are adapted, the lifetime of the charger and the charged battery is prolonged to the greatest extent, and environmental friendliness of society is achieved.

The invention discloses a photoelectric high-power microwave amplification method based on a wide-band-gap semiconductor device, and aims to solve the problems of low output power and low amplification efficiency of an existing amplification circuit. According to the technical scheme, firstly, a B-type push-pull amplification circuit based on a wide-band-gap semiconductor device is constructed, wherein the B-type push-pull amplification circuit is composed of two power supplies, two pulse forming devices, two wide-band-gap semiconductor devices, two current-limiting resistors, a load resistorand a grounding end; the two paths of laser pulses and the voltage generated by the two direct-current power supplies act on two wide-band gap semiconductor devices in the amplifying circuit at the same time; the two wide-band-gap semiconductor devices work as light-operated variable resistors under the excitation of photoelectric signals, and the on-resistance of the two wide-band-gap semiconductor devices is linearly changed along with the light intensity of the high-energy pulse cluster laser, so that the output current and the light intensity are changed in a direct proportion, and photoelectric microwaves are amplified. The amplifying circuit is simple in structure, high in working voltage and high in microwave output power, the unipolar limitation is eliminated, and the problem of low output power is effectively solved.

The invention discloses an automatic frequency calibration system for an electric duplexer, which relates to the field of microwave communication. The system includes a frequency calibration unit, a first switch, a second switch, a generator filter, a receiver filter, a circulator, a radio frequency self-circulator, and a low-noise amplifier; the frequency calibration unit performs frequency conversion amplification and filtering on the received signal , the filtered signal is sequentially sampled, compared, judged and counted. After reaching the preset threshold, the output sends the specified frequency to the generator filter or outputs the specified frequency to the receiver filter. The invention cooperates with the frequency calibration unit and the switch to make the electronically adjustable duplexer realize automatic frequency calibration, which has the characteristics of intelligence and high degree of automation; the combination of electromechanical, soft and hard, can automatically change the calibration working frequency in a wide frequency range ; The tuning speed is fast, and the accuracy and stability of the duplexer's operating frequency are maintained in high and low temperature environments; it is a highly versatile and highly integrated automatic frequency calibration system for electronically tuned duplexers.

The invention relates to a chiral manganese oxide nanoparticle, a preparation method and application thereof, and relates to the technical field of material chemistry. In the chiral manganese oxide nanoparticles described in the present invention, the chiral manganese oxide nanoparticles are obtained by reacting a manganese precursor, tartaric acid and a reducing agent under alkaline conditions; the tartaric acid is L-tartaric acid or D-tartaric acid. The chiral manganese oxide nanoparticles described in the present invention have chiral optical activity at 300-900nm, the preparation method is simple, and the applications are wide. is of great significance.