Abstract: The present invention discloses a photovoltaic power generation virtual inertia compensation system based on SCES, comprising a photovoltaic array, a boost circuit and a grid-connected inverter, which are electrically connected in sequence, and further comprising a supercapacitor assembly for energy storage, a bidirectional DC-DC converter and a virtual inertia control module; an end of the bidirectional DC-DC converter is electrically connected to an output end of the unidirectional DC-DC boost circuit and an input end of the power grid inverter, and the other end thereof is electrically connected to the supercapacitor assembly; the bidirectional DC-DC converter comprises two power switch devices; the virtual inertia control module comprises a first inverting adder, a virtual inertia converter, a second inverting adder, a first PI controller, a third inverting adder, a second PI controller and a PWM modem, which are electrically connected in sequence.

Abstract: A virtual simulation manufacturing platform based on automatic control is provided. The platform comprises an integrated control system, a process treatment system, a virtual simulation system and a signal feedback system, wherein a data end of the integrated control system is connected to a data end of the process treatment system, the data end of the process treatment system is connected to a data end of the virtual simulation system, the data end of the virtual simulation system is connected to a data end of the signal feedback system. A physical workshop during the actual production process is connected to a virtual workshop on a computer by means of a digital twinning technology, and related information such as related process parameters and device parameters are completely displayed in the virtual simulation system in the virtual simulation manufacturing platform based on automatic control.

Abstract: The present application relates to a cell cryopreservation protective composition, the use of the composition, and a cell cryopreservation method. The cell cryopreservation protective composition comprises a zwitterionic molecule having the general formula R1—N+(CH3)2—(CH2)n—R2, wherein R1 is a linear or branched alkyl having 1 to 10 carbon atoms, and is optionally substituted with a substituent; R2 is any negatively charged group selected from the group consisting of —COO?, —SO4?, —SO3?, and (I); and R3 is a group selected from the group consisting of (methyl)acryloyloxyalkyl, alkyl and alkenyl; and the zwitterionic molecule having general formula R1—N+(CH3)2—(CH2)n—R2 is preferably a betaine compound. The cell cryopreservation protective composition can carry out cell cryopreservation in a non-toxic and efficient manner, and results in an extremely high post-thaw cell survival rate and does not require stepwise cryopreservation.

Abstract: Provided is a source-load cooperation access method for a power distribution region. The method includes: establishing a timing feature model of a distributed generator and a timing feature model of a load respectively, acquiring a timing feature of the distributed generator in an access power distribution region by using maximum likelihood estimation and acquiring a timing feature of a user which accesses the power distribution region by using classification and regression trees; and inputting the timing feature of the distributed generator and the timing feature of the user which access the power distribution region into a combination optimization model, and determining a source-load access feeder through optimization.

Abstract: The present application discloses a supported PtZn intermetallic alloy catalyst, a method for preparing the same and application thereof. The catalyst uses SiO2 as a support and Zn as a promoter, and a small amount of active component Pt is supported; the weight percentage of Pt is 0.025%-1%, and the weight percentage of Zn is 0.025%-1.7%, a co-impregnation method is adopted in preparation, the SiO2 support is impregnated in aqueous solution of chloroplatinic acid and zinc nitrate, and then drying and high-temperature reduction are performed to obtain a PtZn/SiO2 catalyst. The catalyst has the advantages of high activity, high stability, low price and low toxicity. The catalyst provided by the present application is applicable to preparation of alkene through short-chain alkane dehydrogenation, in particular to preparation of propylene through propane dehydrogenation in a hydrogen atmosphere.

Abstract: The present invention discloses a residual pressure measurement system for a MEMS pressure sensor with an F-P cavity and method thereof, the measurement system includes a low-coherence light source, a 3 dB coupler, a MEMS pressure sensor, an air pressure chamber, a thermostat, a pressure control system, a cavity length demodulator, an acquisition card and a computer. The measurement method comprises: performing cavity length measurement by using the reflecting light by the pressure control system at two temperatures, respectively, so as to calibrate the MEMS pressure sensor and establish a relationship between the absolute phase of a monochromatic frequency and the external pressure; performing linear fitting to the two measurement data to obtain all the external pressure when the cavity length of two measurement data are equal to each other, and substituting the theoretical equation for calculation to obtain the residual pressure under the flat condition of the diaphragm.

Abstract: Disclosed is a cascade water recycling intelligent system for shale gas exploitation, comprising a cascade water recycling system, wherein a data output end of the cascade water recycling system is connected with a data input end of an information system, a data output end of the information system is connected with a data input end of a decision making system, and a data output end of the decision making system is connected with a regulator; the cascade water recycling system comprises at least one time of water quantity judgment, a current exploiting intensity of shale gas is continued under a condition that the water quantity does not exceed a water safety threshold; and monitoring data is transferred to the information system under a condition that the water quantity exceeds the water safety threshold; the information system is further used for transferring the collected data to the decision making system.

Abstract: The present invention belongs to the bioengineering field, and relates to a method for fermentation production of L-theanine by using an Escherichia coli genetically engineered bacterium. The engineered bacterium is obtained by serving a strain as an original strain, wherein the strain is obtained after performing a single copy of T7RNAP, a dual copy of gmas, xylR knockout, and sucCD knockout on an Escherichia coli W3110 genome, and by integrating genes xfp, pta, acs, gltA, and ppc, and knocking out ackA on the genome. The present invention has a high yield, and stable production performance; after 20-25 h, L-theanine has a titer of 75-80 g/L, and the yield is up to 52-55%. The fermentation broth is purified by membrane separation in combination with a cation-anion resin series technique. Moreover, the one-step crystallization yield is 72.3% and the L-theanine final product has a purity of 99%.

Abstract: A method of using lactase for generating galactooligosaccharide as well as the preparation and an application of the lactase are provided. Lactase (BglD305 derived from Bacillus circulans B2301 and BglD derived from Bacillus circulans ATCC 31382) molecules from two sources are taken as the basis for molecular evolution, so as to obtain new lactase enzyme molecules with high galactooligosaccharide synthesis efficiency and good expression performance. The high-producing strain lactase is further constructed, the lactase can be efficiently synthesized during the submerged fermentation, and the enzyme molecule is secreted into the culture medium, the high-activity enzyme preparation is directly prepared from the fermentation supernatant, and the lactase expression level can achieve 2208 U/mL. As the result, the fermentation manufacturing cost of lactase is reduced, the fermentation manufacturing process is simplified, and the quality of the lactase preparation is improved.

Abstract: The invention discloses an adaptive fault clearing scheme for an MMC VSC-HVDC grid based on source-grid coordination. A grid-side circuit breaker topology is disposed at each end of each DC line of the MMC VSC-HVDC grid to coordinate with a source-side control strategy when a fault occurs to the DC line so as to isolate the fault together. When a system runs stably, the voltage regulation controller does not actuate, after the fault occurs, the voltage regulation controller is started, and the output voltage regulation coefficient decreases, so that voltage at outlets of the converters drops accordingly, and coordinates with voltage of the pre-charging capacitor of the grid-side circuit breaker topology to realize fault isolation based on source-grid coordination. The adaptive fault clearing scheme provided by the invention greatly improves the speed of fault isolation.

Abstract: The invention relates to the field of software management and is intended to invent a blockchain-based software version data management system and an establishing method thereof. The system mainly comprises a data acquisition module, a data transmission module and a data consensus module, wherein the data acquisition module involves data generation, data splicing, and data encapsulation, and provides functions such as acquisition of software version data and structural processing function; the data transmission module involves data communication, data parsing and data forwarding and provides a transmission function for the software version data; the data consensus module involves block synchronization, data verification and consensus mechanism and provides reliability test for the software version data, system new block generation and node data synchronization.

Abstract: The invention discloses a high voltage rechargeable Zn—MnO2 battery. The structure of the Zn—MnO2 battery includes zinc electrode/alkaline electrolyte/ion exchange membrane/acid electrolyte/MnO2 electrode. The ion exchange membrane comprises a cation exchange membrane, an anion exchange membrane or a proton exchange membrane. According to the invention, by using a composite electrolyte system (alkaline electrolyte/ion exchange membrane/acid electrolyte), a high voltage rechargeable Zn—MnO2 battery is obtained. According to the invention, an open circuit voltage of up to 2.7V is obtained, greatly improving the discharge voltage, and at the same time increasing the discharge capacity and enabling cyclic charge and discharge. The invention is of great importance in science research, beneficial to society and economics.

Abstract: Disclosed herein are integrated preparation and detection devices for studying biomass-burning aerosols, where the devices include a micro-fluidized bed reactor (MFBR), a transmission line, and an on-line detection unit that are connected in sequence. The MFBR may include a pyrolysis reactor and a pyrolysis furnace; the pyrolysis reactor may include a thermocouple, an introduction tube, and quartz sands; the on-line detection unit may be an on-line photoionization mass spectrometer; and the photoionization mass spectrometer may include a laser desorption system, a laser ionizer and a light energy ionizer. Devices of the present disclosure are beneficial to retain the original state of aerosol particles, and the fixed MFBR can realize rapid pyrolysis of a biomass due to its high and stable heat conduction efficiency, which is beneficial to studying the formation mechanism of aerosol particles.

Abstract: Disclosed is a bionic fish single-degree-of-freedom modular structure based on a cam mechanism. The bionic fish single-degree-of-freedom modular structure comprises a plurality of modules which are sequentially connected, wherein the foremost one of the modules is a fish head module, and the last one of the modules is a fish tail module; each module in the modules comprises a rack, a rotating shaft is arranged in the center of the rack in a penetrating mode, the second end of the rotating shaft of the previous module is connected to the first end of the rotating shaft of the next module through a universal coupling, the next module is connected with the previous module through a swing connecting piece, and the effect that the modules swing in a plane is achieved, wherein the swing connecting pieces comprises cylindrical cams, pin shafts, first bearings and second bearings; and through combination of the modules, the swimming postures of fishes can be achieved.

Abstract: A PETx polymer including a main backbone which is a first poly-L-lysine, and a side chain which is sequentially connected with a first polyethylene glycol and a second poly-L-lysine, where the second poly-L-lysine is saturately connected with a second polyethylene glycol and a third polyethylene glycol with no remaining amino groups, and the third polyethylene glycol is connected with a functional group at its end, where the first poly-L-lysine and the second poly-L-lysine have the same or different chain lengths, and the first polyethylene glycol, the second polyethylene glycol and the third polyethylene glycol have the same or different chain lengths. Preferably, the PETx polymer is PLL-g-{PEGk-PLL-g-[(PEGj-biological recognition group)y %(PEGi)1-y %]}x %, where i, j, k, m, and n are all integers greater than or equal to 1, j is not equal to i, and x and y are all greater than 0 and less than 100.

Abstract: Disclosed is a targeted delivery system for a hydrophobic antitumor drug, referring to conjugates of E-selectin polypeptide ligand-polyethylene glycol-antitumor drug connected by different link bridges containing disulfide bonds. The synthesis of the conjugates, antitumor activity evaluation, the particle size and morphology characteristics of nanoparticles self-assembled by the conjugates in an aqueous solution, and the release of the antitumor drug in different conditions are comprised. The conjugates can actively target at vessels of a tumor site by the E-selectin peptide ligand, and can also self-assemble into nanoparticles in an aqueous solution, so as to be passively targeted at the tumor site by EPR effect.

Abstract: The present invention related to the field of power system protection and control, presents a voltage travelling wave differential protection method considering the influence of frequency-dependent parameters, which provides more accurate and rapid fault identification. The technical scheme of the present invention is as follows: a calculation method of voltage travelling-wave differential protection for VSC-HVDC transmission lines, taking the influence of the frequency-dependent parameters into consideration, the steps are as follows: calculating a characteristic impedance and propagation coefficient of the frequency-dependent transmission line in time domain, collecting voltage and current signals at the both ends of the transmission line and then calculating the forward and backward voltage travelling wave, respectively, comparing a differential value of voltage travelling wave with a preset threshold value to determine whether the internal fault occurs.

Abstract: A superhydrophobic polypropylene porous film, including a polypropylene porous film substrate, titanium dioxide layers and a surface modifier layer, is disclosed. The titanium dioxide layers are deposited on the surface of the polypropylene porous film substrate by atomic deposition technology; a surface modifier is coated on the titanium dioxide layers; hydrophobic bonds are formed between the titanium dioxide layers and the surface modifier layer; the superhydrophobic polypropylene porous film has a water contact angle greater than 150 degrees, a rolling angle less than 10 degrees, an aperture of 0.1-0.4 ?m, a porosity of 50%-80%, a tensile strength of 30-50 MPa, and an elongation at break of 10%-30%.

Abstract: The present disclosure provides a method for correcting a light intensity measurement value is provided. The method includes: emitting detection light into a measured object; measuring a light intensity measurement value at a measurement position, and measuring light intensity of photons at a benchmark position as a light intensity reference value. A sensitivity of the light intensity of photons to a concentration change of a specific substance in the measured object is less than or equal to a preset threshold, and a change rate of the light intensity at the measurement position with a concentration of the specific substance in the measured object is greater than a change rate of the light intensity at the benchmark position with the concentration of the specific substance; correcting the light intensity measurement value by using the light intensity reference value. The present disclosure further provides a concentration measurement device.

Abstract: A large-particle spherical salt with a particle size of 400-950 ?m and a sphericity of 0.5-1.0 is disclosed, which overcomes the existing difficulty in this field for larger particle size as well as higher sphericity. A preparation method of the large-particle spherical salt is also disclosed, wherein in one preparation process, 2% of gum arabic (based on the mass percentage of solute sodium chloride in a sodium chloride saturated solution) is added, and under conditions of an evaporating temperature of 60° C. a stirring rate of 350 rpm, and an evaporating time of 8 hours, a large-particle spherical salt with a particle size of 921.593 ?m and an average sphericity of 0.904 is successfully prepared. The large-particle spherical salt prepared by the method has a uniform particle size distribution and good appearance, can be combined with other substances, adding some extra value to the salt. Meanwhile, the large-particle spherical salt prepared by the method has a high safety grade (e.g.