Abstract: It is provided a power generation model based on a transcritical cycle with an increasing-pressure endothermic process using CO2-based mixture working fluids for an enhanced geothermal system, including a geothermal water circulation, a mixture working fluid circulation and a cooling water circulation. A coaxial pipe-in-pipe downhole heat exchanger is provided in the mixture working fluid circulation. Innovations are reflected in that an increasing-pressure endothermic process is achieved due to making use of gravity and hence increase a heat quantity absorbed in a cycle, thereby improving power generation quantity of the cycle; and a binary mixture working fluid composed of CO2 and an organic working fluid is adopted to realize a transcritical power cycle with an increasing-pressure endothermic process and a decreasing-temperature exothermic process, thereby effectively reducing irreversibility of a heat transfer between a working fluid and a heat source and improving power cycle efficiency.

Abstract: The present disclosure relates to the field of genetic engineering, especially relates to a xylose-induced genetically engineered bacteria used for producing ectoine as well as a construction method and use thereof. The genetically engineered bacteria is constructed by heterologously expressing the ectABC gene cluster from Halomonas elongata on the E. coli chromosome, using the promoter of xylose transporter coding gene xylF to control the RNA polymerase from T7 bacteriophage, reconstructing a synthesis pathway of ectoine and constructing a plasmid-free system, and enhancing the expression of target genes by a strong promoter T7; the yield of ectoine reached 12-16 g/L after 20-28 h fermentation in shake flask, and reached 35-50 g/L after 24-40 h fermentation in a 5 L fermentor.

Abstract: A genetically engineered bacterium includes a genome of the Eschericia coli and a mutant encoding gene hisG* of a Corynebacterium glutamicum ATP phosphoribosyl transferase HisG on the genome, and the gene hisG* is strongly expressed to enhance activity of a key enzyme HisG for histidine synthesis. The gene hisG* has a nucleotide sequence as shown in SEQ ID NO: 1; a copy number of histidine operon genes hisDBCHAFI of the Eschericia coli is further increased on the genome to enhance a terminal synthetic route of histidine; an encoding gene lysE from an arginine/lysine transportprotein of the Corynebacterium glutamicum is further integrated to the genome and strongly expressed to promote the intracellular histidine secrete to the extracellular space; and an encoding gene rocG of glutamate dehydrogenase of Bacillus subtilis is further integrated to the genome and strongly expressed to promote generation of histidine.

Abstract: Provided is a p-type TiO2/n-type WO3 heterojunction catalyst and a preparation method and use thereof. The catalyst comprises p-type TiO2 and n-type WO3 supported on a surface of the p-type TiO2.

Abstract: A method for enhancing degradation of ester volatile organic compounds with a cerium oxide supported palladium single atom catalyst under low-temperature microwave comprises the steps of firstly preparing a single atom catalyst Pd/CeO2, adding the catalyst Pd/CeO2 into a reaction cavity, initiating microwave radiation to enhance the catalysis reaction, and quickly introducing an ester compound with a concentration of 50˜5000 mg/m3 and a space velocity of 2000˜100000 h?1 into the reaction cavity from a vapor phase sampling port to react when the reaction temperature is 10˜80° C. A catalyst packed column is provided in the reaction cavity, the vapor phase sampling port is defined at the bottom of the reaction cavity, and an exhaust port is defined at the top of the cavity. The microwave method can enhance and activate active sites, prevent the aging of active sites, and enable the chemical reaction rate to be increased by more than 17.9%.

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: 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: 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 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: 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: 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: An Aureobasidium pullulans recombinant strain with high-yield heavy oil and a construction method and application thereof are provided. The Aureobasidium pullulans recombinant strain is obtained by knocking out a pullulan synthetase PUL gene while overexpressing an ACL gene. The obtained Aureobasidium pullulans recombinant strain can significantly increase the yield of heavy oil. After 7-day fermentation with xylose as carbon source, the yield of the heavy oil of the recombinant strain reaches 19.4372 g/L, while the yield of the heavy oil of the original strain is 10.0325 g/L, i.e. the recombinant strain improves the yield by 93.74% compared with the original strain.

Abstract: The present application relates to use of Prussian blue nanoparticles in the preparation of a medicament for the prevention, delay or treatment of neurodegenerative disease. The present application finds that Prussian blue nanoparticles have significant effects in the prevention, delay or treatment of neurodegenerative disease. Cell test results show that Prussian blue nanoparticles can reduce the level of ROS in nerve cells stimulated by hydrogen peroxide and increase the proportion of living cells in nerve cells stimulated by hydrogen peroxide. Animal test results show that Prussian blue nanoparticles can significantly reduce the expression level of oxidative stress markers in the hippocampus of mouse models of neurodegenerative disease, and significantly improve the learning and memory abilities and ameliorate motor dysfunction of mouse models of neurodegenerative disease.

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 present invention discloses a modular multilevel dynamic switching DC-DC transformer, which consists of N DC-DC sub-modules connected in series. Each of the DC-DC sub-modules is of a symmetrical structure capable of realizing bidirectional power flow, which consists of two half-bridge sub-modules and isolating switches S1, S2 between capacitors C1, C2 of the two half-bridge sub-modules. The capacitors C1, C2 are disposed in parallel between the half-bridge sub-modules and the isolating switches. Assuming that the power flows in the primary side of the DC-DC transformer and flows out from the secondary side; the half-bridge sub-module located on the primary side of the DC-DC transformer is referred to as a primary-side sub-module; and, the half-bridge sub-module located on the secondary side of the DC-DC transformer is referred to as a secondary-side sub-modules.

Abstract: The present invention discloses a method for detecting the mechanical response of a mechanical component by an organic mechanoresponsive fluorescent material, comprising the following steps of: selecting an organic mechanoresponsive fluorescent material; preparing an organic mechanoresponsive fluorescent material solution; forming a film on a metal surface; calibrating fluorescence intensity and obtaining the fluorescence intensity and distribution in a crack tip area; observing the fluorescence signal generated at cracks to monitor the occurrence of fatigue cracks, and predict a propagation pathway of fatigue cracks by using the fluorescence intensity distribution in the crack tip area.

Abstract: An electromagnetic braking system and control method, with the system having a CCU, a braking cylinder, a push rod, an electromagnetic braking ring, an electromagnetic braking piston fixed to the push rod, a first shading plate and a second shading plate, a photoelectric sensor fixed near the push rod, and an electromagnetic braking control circuit, and the control method including following the steps: initial estimating of the braking distance (l) according to the current magnitude, electromagnetic force between the two electromagnetic coils and initial velocity (v) of the push rod, arranging a restoration distance (?l) between the top dead center and the piston after braking, installing two shading plates and the photoelectric sensor; and setting the distance between the two electromagnetic coils to when the starts braking.