Abstract: A control system of a flexible permanent magnet brushless DC motor, comprising a DC power supply, a filter capacitor, a voltage source inverter, a permanent magnet brushless DC motor and a controller, wherein an output end of the DC power supply is connected with the filter capacitor in parallel; the voltage source inverter is provided with m bridge arms which are connected with both ends of the filter capacitor in parallel; upper and lower controllable switching devices are arranged on each bridge arm; the phase number of armature winding of the permanent magnet brushless DC motor is equal to the number of bridge arms; head ends of armature windings of each phase are correspondingly connected with intermediate contacts of the upper and lower controllable switching devices of one bridge arm, tail ends of armature windings of each phase are connected together.

Abstract: A blood pressure tracking and detection system. The pressure application and release module is configured to apply a pressure to a detected part of a target user according to a pressure application instruction. The pressure application and release module is further configured to release the pressure on the detected part of the target user according to a pressure release instruction. The signal obtaining module is connected to the pressure application and release module. The signal obtaining module is configured to obtain a photoplethysmography (PPG) signal and a pressure signal of the detected part of the target user. The blood pressure tracking and detection module is connected to the signal obtaining module. The blood pressure tracking and detection module is configured to determine an initial blood pressure of the detected part of the target user according to a PPG signal and a pressure signal in a pressure application and release cycle.

Abstract: The invention relates to the field of industrial wastewater treatment, and particularly discloses a nanofiltration membrane for treating printing and dyeing wastewater and its preparation method. The preparation method comprises the following steps: S1, pouring an aqueous solution containing m-phenylenediamine, camphorsulfonic acid and triethylamine onto the surface of a polysulfone ultrafiltration membrane, setting still for 10 s to 30 s, and then removing the excess aqueous solution from the surface; S2, pouring an organic solution containing trimesoyl chloride and an interface auxiliary polymerization agent onto the surface of the membrane obtained in step S1, reacting for 5 s to 20 s, and then removing the excess solution from the surface; and S3, setting the membrane obtained in step S2 still and then carrying out heat treatment and water rinsing on the membrane in sequence, thus obtaining the nanofiltration membrane.

Abstract: The present application relates to a preparation method for recycling inorganic salt in printing and dyeing wastewater and comprises the following process steps: S1, performing impurity removal, softening, COD removal and decoloration on reverse osmosis (RO) membrane concentrated water to obtain pretreated wastewater; S2, performing two-stage electrodialysis on the wastewater obtained in step S1: returning fresh water obtained in a first-stage electrodialysis desalination chamber to a front end of the RO process, and taking saline water obtained in a concentration chamber as raw water of a second-stage electrodialysis desalination chamber and a second-stage electrodialysis concentration chamber; and returning the fresh water obtained by the second-stage electrodialysis desalination chamber to the first-stage electrodialysis concentration chamber; and S3, dealkalizing the concentrated saline water obtained in the step S2 and then adjusting the pH value to obtain concentrated saline water capable of being reuse

Abstract: The present disclosure provides the synthesis of an imidazolium-based functional ionic liquid copolymer (PMMA-b-PIL-R*) and a preparation method of an alloy ultra-filtration membrane. Firstly, PMMA-b-PIL-R* is prepared from methyl methacrylate (MMA) and polymerizable imidazolium-based functional ionic liquid (IL-R*) containing double bonding as the reactive monomers through sequential radical polymerization. With the use of a non-solvent induced phase separation method, PMMA-b-PIL-R* is introduced into the body of a polymeric membrane material, so as to prepare an alloy ultra-filtration membrane. A hydrogen-bond interaction is generated between the carbonyl in the molecular chain of PMMA-b-PIL-R* and the H . . .

Abstract: The invention relates to the field of industrial wastewater treatment, and particularly discloses a nanofiltration membrane for treating printing and dyeing wastewater and its preparation method. The preparation method comprises the following steps: S1, pouring an aqueous solution containing m-phenylenediamine, camphorsulfonic acid and triethylamine onto the surface of a polysulfone ultrafiltration membrane, setting still for 10 s to 30 s, and then removing the excess aqueous solution from the surface; S2, pouring an organic solution containing trimesoyl chloride and an interface auxiliary polymerization agent onto the surface of the membrane obtained in step S1, reacting for 5 s to 20 s, and then removing the excess solution from the surface; and S3, setting the membrane obtained in step S2 still and then carrying out heat treatment and water rinsing on the membrane in sequence, thus obtaining the nanofiltration membrane.

Abstract: A three-port converter with a wide input range and a control method thereof are provided, which relates to a technical field of power electronic converters. The converter is provided with three ports of a photovoltaic cell PV, a storage battery Bat and a resistance load R, and includes a boost circuit (Boost) and a reversible boost-buck circuit (Sepic-Zeta). The boost circuit is configured to connect the photovoltaic cell PV and the load R; and the reversible boost-buck circuit is configured to connect the photovoltaic cell PV, the storage battery Bat, the storage battery Bat and the load R. The three-port converter of the present disclosure has advantages of a small size, a wide input range, a high integration level, high stability, high conversion efficiency, etc.

Abstract: Disclosed in the present invention are a low energy consumption anhydrous CO2 phase change absorption agent, and a regeneration method and an application thereof, the absorption agent using a unitary diamine with a primary amine (NH2—) and a tertiary amine (—N—), and not containing any other organic solvent, water, and ionic liquid; two alkyl branches are linked to a nitrogen atom of the tertiary amine, forming a certain hydrophobicity; after absorbing the CO2, the diamine changes from a liquid phase to a solid phase, undergoing liquid-solid phase change to form white amino formate crystals.

Abstract: Disclosed are a light-driven filtration antibacterial composite membrane and a preparation method and use thereof. The method for preparing the light-driven filtration antibacterial composite membrane includes: mixing dichloromethane and N,N-dimethylformamide to obtain a first solution; adding PCL particles to the first solution, and stirring until being uniform to obtain an electrospinning solution; adding a ZIF-8 powder to the electrospinning solution, and ultrasonically dispersing for at least 1 hour to obtain a PCL/ZIF-8 spinning solution; spraying the PCL/ZIF-8 spinning solution onto a PPCL@PDA/TAEG men-blown membrane to obtain the light-driven filtration antibacterial composite membrane.

Abstract: A motor fault detection system is based on coupling injection of high-frequency signal. An input end of the motor is connected with the high-frequency detection signal source circuit through the coupling circuit to inject a high-frequency detection signal into the motor winding; an input end of the high-frequency detection signal source circuit is connected with an output end of the controller to control the output of the high-frequency detection signal; an output end of the response signal processing circuit is connected with an input end of the controller to send the received voltage or current response signal to the controller; and the controller judges whether the motor has a fault and the degree of the fault by analyzing the response signal after applying an excitation.

Abstract: The invention provides a piezoelectric electromagnetic combined energy harvester based on parallel mechanism. The harvester includes fixed bracket, three groups of motion branches and movable bracket. The movable bracket includes bottom platform, the bottom platform support frame and the bottom platform connector. The invention realizes multi-direction telescopic motion, and the magnetic flux of the coil is constantly changing, generating induced electromotive force. The vibration of piezoelectric beam causes the polarization of piezoelectric material and produces the output voltage. The invention uses parallel mechanism to introduce twelve piezoelectric beams, twelve permanent magnets and twenty-four coils in a small working space.

Abstract: A flexible photonic skin is provided, including a functional layer, an adhesive layer used for fixing the functional layer and made of hypoallergenic polyvinyl ethyl ether, and a packaging layer made of a polyurethane semi-transparent film and adhered to the adhesive layer, which are arranged successively from the top down, wherein the functional layer consists of two electrodes located on two sides and used for acquiring electrocardiographic signals of a human body, and a polymer-based photonic integrated chip located between the two electrodes and used for acquiring body temperature, pulse, blood pressure and blood glucose signals of the human body; and, the polymer-based photonic integrated chip processes and outputs the acquired electrocardiographic signals of the human body as well as the body temperature, pulse, blood pressure and blood glucose signals of the human body.

Abstract: The present application relates to a preparation method for recycling inorganic salt in printing and dyeing wastewater and comprises the following process steps: S1, performing impurity removal, softening, COD removal and decoloration on reverse osmosis (RO) membrane concentrated water to obtain pretreated wastewater; S2, performing two-stage electrodialysis on the wastewater obtained in step S1: returning fresh water obtained in a first-stage electrodialysis desalination chamber to a front end of the RO process, and taking saline water obtained in a concentration chamber as raw water of a second-stage electrodialysis desalination chamber and a second-stage electrodialysis concentration chamber; and returning the fresh water obtained by the second-stage electrodialysis desalination chamber to the first-stage electrodialysis concentration chamber; and S3, dealkalizing the concentrated saline water obtained in the step S2 and then adjusting the pH value to obtain concentrated saline water capable of being reuse

Abstract: A four-sided-synchronous-swing dual-mode broadband power generation device, comprising a fixing frame, a piezoelectric beam swing mechanism, and electromagnetic induction power generators (7). Four groups of straight piezoelectric beams (6) and L-shaped piezoelectric beams (5) are installed in a small space, therefore, a limited working space can be fully utilized, the working area can be reduced, and the requirements for development of a microelectromechanical system can be satisfied. Each L-shaped piezoelectric beam (5) comprises a horizontal beam and a vertical beam, so that vibration in two directions can be implemented, therefore, the dynamic behavior of piezoelectric cantilevers is enriched, and the power generation efficiency of the system is improved. The straight piezoelectric beams (6) and L-shaped piezoelectric beams (5) have different lengths, so that energy of different swing frequencies can be effectively harvested, and the effective working frequency bandwidth can be broadened.

Abstract: The present disclosure provides the synthesis of an imidazolium-based functional ionic liquid copolymer (PMMA-b-PIL-R*) and a preparation method of an alloy ultra-filtration membrane. Firstly, PMMA-b-PIL-R* is prepared from methyl methacrylate (MMA) and polymerizable imidazolium-based functional ionic liquid (IL-R*) containing double bonding as the reactive monomers through sequential radical polymerization. With the use of a non-solvent induced phase separation method, PMMA-b-PIL-R* is introduced into the body of a polymeric membrane material, so as to prepare an alloy ultra-filtration membrane. A hydrogen-bond interaction is generated between the carbonyl in the molecular chain of PMMA-b-PIL-R* and the H . . .

Abstract: A position-sensorless control method and device for long-cable drive permanent magnet motors, including: adding a coupling circuit after boost transformers in the long-cable drive circuit of a permanent magnet motor; coupling three high frequency detection signals with different frequencies into a power supply cable and windings of the motor through three coupling transformers in the coupling circuit respectively; obtaining high frequency voltage components on primary windings of the coupling transformers by bandpass filters; obtaining the position signals according to relations among effective values of the high frequency voltage components; and finally realizing the position-sensorless control of the motor by a controller according to the obtained position signals.

Abstract: Disclosed in the present disclosure are a low energy consumption anhydrous CO2 phase change absorption agent, and a regeneration method and an application thereof, the absorption agent using a unitary diamine with a primary amine (NH2—) and a tertiary amine (—N—), and not containing any other organic solvent, water, and ionic liquid; two alkyl branches are linked to a nitrogen atom of the tertiary amine, forming a certain hydrophobicity; after absorbing the CO2, the diamine changes from a liquid phase to a solid phase, undergoing liquid-solid phase change to form white amino formate crystals.