Abstract: A microchannel heat exchanger structure with a nozzle and a working method thereof. The microchannel heat exchanger structure with a nozzle, includes a first heat exchange portion, a second heat exchange portion, and at least one nozzle portion between the first heat exchange portion and the second heat exchange portion, the first heat exchange portion having a high-pressure heat exchange channel, a first micro-fin array being provided inside the high-pressure heat exchange channel, and the second heat exchange portion having a low-pressure heat exchange channel, the high-pressure heat exchange channel and the low-pressure heat exchange channel being in communication through at least one nozzle disposed in the nozzle portion. The heat exchanger structure has a good heat exchange effect and can achieve a better heat flux during heat exchange.

Abstract: The present invention provides an event positioning method, device and application in a distributed fiber vibration monitoring system. When a location at which an event occurs in a sensing fiber is to be positioned, an interference field signal having a maximum optical power is obtained by comparing optical powers of respective interference field signals corresponding to backward Rayleigh scattering lights that are generated when a pulse light is transmitted in the sensing fiber. Subsequently, a sensing location of the interference field signal having the maximum optical power is calculated. Finally, the location at which the event occurs in the sensing fiber is determined, according to the sensing location and a location distribution pattern of the event. According to the positioning method provided in the present invention, by screening the interference field signals and then calculating the event location, the spatial resolution is not determined merely by the pulse width of the optical signal.

Abstract: A hierarchical voltage control system is provided. A supercapacitor unit and a lithium battery unit are both connected to a DC bus to form a parallel-structure-type hybrid energy storage system, and are each configured with a power device and a switch to control a connection relationship between the corresponding unit and the DC bus. A detection circuit detects current and voltage values of the supercapacitor unit, the lithium battery unit, and the DC bus, detects an operating parameter of a power conversion system, and transmits the operating parameter to a processor, the power conversion system being connected in parallel to the DC bus for bidirectional power conversion of AC and DC energy sources. A microprocessor determines a system operating condition and uses a hierarchical voltage control strategy to control charging and discharging states of the supercapacitor unit and the lithium battery unit.

Abstract: A heat-resistant and soluble magnesium alloy, and a preparation method having an elemental composition at the following atomic percentage: Lu 0.10% to 8.00%, Ce 0.001 to 0.05%, Al 0.10% to 0.60%, Ca 0.001% to 0.50%, Cu 0.01% to 1.00%, Ni 0.01% to 1.00%, impurity elements <0.30%, and the rest is Mg, and formed in magnesium alloys are high temperature phase of Lu5Mg24, Mg2Cu, Mg2Ni, Mg12Ce, Al11Ce3 and (Mg, Al)2Ca, and Long Period Stacking Ordered (LPSO) phases as Mg—Lu—Al and Mg—Ce—Al. The magnesium alloy has good mechanical performances at 150° C., and a dissolution rate of 30 to 100 mg·cm?2h?1 in a 3% KCl solution at 93° C.

Abstract: The present invention provides an event positioning method, device and application in a distributed fiber vibration monitoring system. When a location at which an event occurs in a sensing fiber is to be positioned, an interference field signal having a maximum optical power is obtained by comparing optical powers of respective interference field signals corresponding to backward Rayleigh scattering lights that are generated when a pulse light is transmitted in the sensing fiber. Subsequently, a sensing location of the interference field signal having the maximum optical power is calculated. Finally, the location at which the event occurs in the sensing fiber is determined, according to the sensing location and a location distribution pattern of the event. According to the positioning method provided in the present invention, by means of screening the interference field signals and then calculating the event location, the spatial resolution is not determined merely by the pulse width of the optical signal.

Abstract: A method for preparing a high-strength extruded profile of an Mg—Zn—Sn—Mn alloy is composed of a solid solution treatment at two stages to a billet, a high-temperature pre-aging to the billet, a low-temperature rapid extrusion and a low-temperature aging treatment to a profile. The Mg—Zn—Sn—Mn alloy includes the following elements in mass percent: 5.8-6.2% of Zn, 3.0-3.5% of Sn, 0.25-0.45% of Mn, unavoidable impurities of 0.05% or less, and the balance magnesium. The Mg—Zn—Sn—Mn magnesium alloy profile has a fine grain size of about 10-20 ?m and a dispersed second phase, so a high strength and a good elongation can be obtained therein, and a tensile strength of 350 MPa or more, a yield strength of 280 MPa or more, and the elongation of 12% or more. In addition, the profile has a high extrusion production efficiency and a highyield, and a low extrusion cost.

Abstract: An optical fiber flow sensor, including: a housing, an elastic component, an optical fiber detection component, a floating element, and a fixed sealing joint. The elastic component includes a first and second elastic members that are symmetrical and are disposed in a closely fitted manner, with fitting surfaces of the first and the second elastic members being respectively provided with a corresponding seating groove. The optical fiber detection component is disposed in the seating grooves, and both ends of the optical fiber detection component are welded in the seating grooves via a glass solder. The elastic component is enclosed in the housing, and one end of the housing is fixed at the fixed sealing joint. The optical fiber detection component is sealed within the elastic component so as to avoid direct contact with an external fluid, and prevent damage by corrosion, hydrogen loss, or the like.

Abstract: An optical fiber distributed monitoring system and method is provided. The system includes a laser device, an acousto-optic modulator, a phase matching interferometer, a photoelectric detector and a phase demodulation module. After entering the phase matching interferometer, the Rayleigh backscattering light containing parameter information output from the sensing optical fiber enters the two arms of the phase matching interferometer respectively, and the light of the two arms of the phase matching interferometer is phase-modulated by the first modulation wave and the second modulation wave, respectively and then interfere with each other to generate interference light. The photoelectric detector converts a light signal into an electric signal, and the phase demodulation module processes the electric signal based on the Hilbert algorithm to obtain the parameter change of the environment under test.

Abstract: A Pseudomonas sp. ECO-1 strain was preserved at the China General Microbiological Culture Collection Center (CGMCC) on Mar. 31, 2017, with the preservation number of CGMCC No. 13960. The Pseudomonas sp. ECO-1 strain was separated from POPs (Persistent Organic Pollutants) polluted soil for the first time. The bifunctional enzyme preparation capable of efficiently degrading polychlorinated biphenyl and atrazine was prepared by utilizing the strain for the first time; especially, the bifunctional enzyme preparation has remarkable degradation activity on the polychlorinated biphenyl which is difficult to degrade under an aerobic condition, which is completely different from functions of existing known Pseudomonas sp. and enzyme preparations thereof.

Abstract: Provided are a temperature sensor and an active phase-shifted grating-based temperature sensing system, relating to a fiber sensing technical field. The temperature sensor comprises a pump laser, a wavelength division multiplexer, an optical detector and an active phase-shifted fiber grating with ? phase shift. Pump light emitted by the pump laser enters the active phase-shifted fiber grating through the wavelength division multiplexer. The active phase-shifted fiber grating absorbs the pump light and emits laser light, which travels back through the wavelength division multiplexer and enters the optical detector. The optical detector measures output power of the active phase-shifted fiber grating, to analyze the power to obtain ambient temperature of the active phase-shifted fiber grating.

Abstract: Provided is a fiber optic acoustic wave detection system, pertaining to the fiber optic sensing technical field. The system comprises a power output apparatus, a backward Rayleigh scattering principle-based first distributed sensing apparatus, a backward weak optical fiber grating reflection principle-based second distributed sensing apparatus, and a third distributed sensing apparatus. The first distributed sensing apparatus and the second distributed sensing apparatus are connected with the power output apparatus, respectively. The first distributed sensing apparatus and the second distributed sensing apparatus are connected with the third distributed sensing apparatus, respectively.