Abstract: A Saccharomyces cerevisiae strain with high yield of ethyl butyrate and a construction method and an application thereof are provided. The strain is obtained by over-expressing in the starting strain acetyl coenzyme A acyl transferase gene Erg10, 3-hydroxybutyryl coenzyme A dehydrogenase gene Hbd, 3-hydroxybutyryl coenzyme A dehydratase gene Crt, trans-2-enoyl coenzyme A reductase gene Ter, and alcohol acyl transferase gene AAT. Compared to the starting bacteria not producing ethyl butyrate, the yield of ethyl butyrate of the constructed strain reaches 77.33±3.79 mg/L, the yield of the ethyl butyrate of the strain with double copy expression of gene Ter and gene AAT reaches 99.65±7.32 mg/L, increased by 28.9% compared with the EST strain, and 40.93±3.18 mg/L of ethyl crotonate is unexpectedly produced.

Abstract: The present disclosure relates to a hierarchical constraint (HC) based method and system for classifying fine-grained graptolite images. The method includes: constructing a graptolite fossil dataset; extracting features in graptolite images; calculating the similarity between graptolite images, and performing weighting according to a genetic relationship among species to obtain a weighted HC loss function (HC-Loss) of all graptolite images; calculating cross-entropy loss; taking a weighted sum of HC-Loss and CE-Loss as a total loss function in a training stage; and performing model training. The system of the present disclosure includes a processor and a memory.

Abstract: The present invention discloses a quantitative evaluation method for sensitivity of welding transverse cold cracks in a typical joint of a jacket, including following steps: S1, performing macroscopic analysis, metallographic analysis, fracture analysis and hardness analysis on cracks of a failed component to obtain main causes of cold crack failure; and S2, designing and processing a dedicated sample, and performing rigid restraint crack tests on the dedicated sample at different preheating temperatures to obtain a cracking/non-cracking critical restraint stress ?1cr of the sample.

Abstract: Provided is a yeast strain capable of excessively synthesizing cAMP and its construction method and fermentation technique thereof, and application in the field of medicine, animal husbandry, food or chemical industry. The yeast strain includes first and second gene modifications, wherein the first gene includes protein kinase A (PKA) catalytic subunit encoding genes TPK1, TPK2 and TPK3, by modifying the first gene, the activity or expression of PKA is completely inhibited, so that feedback inhibition to cyclic adenosine monophosphate (cAMP) is eliminated, but at the same time, the growth of the yeast is inhibited; and the second gene modification eliminates growth inhibition caused by the first gene modification, so that the yeast grows normally, and the cAMP yield by the yeast is increased, wherein the increase of the cAMP yield is relative to the cAMP yield by an unmodified yeast. The yeast strain further includes third and/or fourth gene modifications.

Abstract: Disclosed is a multiple combustion mode engine with ammonia fuel including an cylinder head, a cylinder sleeve, a piston, a main combustion chamber, an inlet valve and an exhaust valve, and further including a jet ignition device arranged on the cylinder head and used for providing an ignition source for the main combustion chamber, and an ammonia injector used for providing ammonia/air mixture gas for the main combustion chamber. Also disclosed is a control method of the multiple combustion mode engine with ammonia fuel. The time sequence of ammonia injection of the main combustion chamber and jet flame generation of the pre-chamber is controlled, the mixed state of the fuel/air in the main combustion chamber before ignition can be controlled, and finally different combustion modes, i.e. a premixed combustion mode and a diffusion combustion mode, are formed in the main combustion chamber.

Abstract: A corrosion-resistant nickel alloy, a preparation method thereof and, and a use thereof are provided. The alloy includes the following components in percentage by mass: 4.68-5.35% of B, 5.69-6.41% of W, 27.68-28.39% of Cr, 12.65-13.42% of Al, and the balance of Ni and inevitable impurities. The alloy disclosed by the present invention is a Ni—W—B ternary alloy with main components of Ni, W and B, wherein the three elements have strong high-temperature corrosion resistance at a temperature of about 600° C., and have the potential of solid solution hardening and precipitate formation because all belong to solid solution forming elements, so that a creep strength of a nickel alloy matrix is improved. Meanwhile, Al and Cr are further added in the alloy formula, so that Al2O3 and Cr2O3 oxide layers can be formed, which play a role as a physical diffusion barrier against chlorine gas and other corrosive gases.

Abstract: The present invention relates to a quick-response voltage control method of distribution systems considering multiple participants, comprising a multiple agent system (MAS), which collects the local information of the distribution system controlled by each agent and interacts with the local information collected by each agent, so that voltage-power sensitivity of the distribution system, used for providing the theoretical basis for voltage regulation, is calculated by distributed calculation; and multiple participants, which establish incentive mechanism by DSOs based on the bidding game with imperfect information, and independently decide their own strategies to obtain the voltage regulation subsidy from the DSOs, according to the calculated voltage-power sensitivities, thus provide voltage support for the distribution system in the process of pursuing benefit maximization.

Abstract: A method for enhancing aggregation state stability of organic semiconductor (OSC) films includes constructing the OSC film; introducing uniform and discontinuous nanoparticles on a surface of the film or an inside of the film. Electrical properties of the OSC film are not influenced by introducing the nanoparticles. Grain boundary, dislocation, stacking fault, and surface of the film are pinned by the nanoparticles, increasing potential barrier of the aggregation state evolution of the film, and thus enhancing the stability of the aggregation state and greatly improving maximum working temperature and storage lifetime of organic field-effect transistors. Under room temperature storage, morphology of the OSC film introduced with the nanoparticles is difficult to change, so that the stability of electrical properties of organic transistor components prepared from the film is ensured in a high-temperature and atmospheric working environment.

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: A source-network coordination type direct-current (DC) circuit breaker based on pre-charged capacitors for an MMC based DC grid is provided. The MMC based DC grid is provided with four converter stations, each having two converters, which are in loop connection through a double-loop DC overhead line. Two ends of each DC line connecting the converters are separately equipped with DC circuit breakers for isolating a fault of the DC line. An MMC active voltage adjusting control strategy is matched with pre-charged capacitor voltage in the self-adaptive mode to provide a beneficial breaking condition for a quick mechanical switch branch, so that the fault line is effectively cut off.

Abstract: Disclosed is an optimizing method for multi-source municipal solid waste combinations based on machine learning, including obtaining relevant property data, classifying the feature variables and obtaining a raw materials pre-combination from the classified feature variables according to a classification ratio, followed by cooperative combustion treatment to obtain data after combustion, summarizing the obtained data into a database, constructing a matrix of raw material components, operating conditions and pollutant distribution according to the database, obtaining matrix data; performing principal component analysis on the matrix data, constructing an information processing model, obtaining a data set of samples; carrying out training according to the data set to construct a relational model, obtaining processed parameters; training the obtained processed parameters to construct a regression module, an optimal parameter, and performing regression calculation using the optimal parameter together with the matr

Abstract: A method for preparing a high-selectivity lithium-magnesium separation membrane includes: (1) preparing an aqueous phase mixture containing aqueous phase monomer, crown ethers or aza-macrocycles, acid acceptor, surfactant and water; (2) preparing an organic phase mixture containing organic phase monomer, and organic solvent that is incompatible with water; (3) contacting the supporting membrane with the aqueous phase mixture to obtain an aqueous phase monomer-adsorbed supporting membrane; (4) contacting the aqueous phase monomer-adsorbed supporting membrane with an organic phase mixture for an interfacial polymerization reaction; and (5) placing a nascent membrane obtained into a drying oven and heat-treating the membrane to obtain a lithium-magnesium separation membrane. The present method is simple in preparation process, mild in preparation conditions, easy to scale up, and easy to realize industrial production.

Abstract: The present invention discloses a high-peak-power single-frequency narrow-linewidth nanosecond fiber laser based on a triangular pulse, wherein the laser includes: pulsed laser generated by the laser seed injecting into a first power pre-amplifier through a first isolator, and then injecting into a second pre-amplifier and then injecting into a power amplifier; wherein triangle-shaped pulsed laser with fast rising edge is obtained by using electro-optic and acousto-optic modulator to modulate continuous wave single-frequency laser or a single-frequency semiconductor laser directly modulated by radio frequency signal; single-frequency triangle-shaped pulsed laser is employed as the laser source according to the characteristics of narrow intrinsic linewidth and suppression of linewidth broadening caused by SPM, and the power of pulsed laser is amplified through the MOPA system.

Abstract: An air-assisted jet flame ignition device includes a housing, a fuel-air premixing unit, and a prechamber. The fuel-air premixing unit includes a fuel injector, an air injection valve, a premixing sleeve, a premixing sleeve inner core placed in the premixing sleeve, and a fuel injector fastening bolt. An inner wall surface of the premixing sleeve and an outer wall surface of the premixing sleeve inner core form a premixing sleeve inner cavity. An inner wall surface of the premixing sleeve inner core, a lower end surface of a nozzle of the fuel injector, and an upper end surface of an air inlet of the air injection valve form a premixing cavity. The premixing cavity coupled to the premixing sleeve inner cavity via a through hole on the sidewall of the premixing sleeve inner core. A prechamber nozzle is fixedly coupled to the lower part of the housing.

Abstract: The present disclosure provides a low-molecular mass organic gellant and a preparation method and use thereof, belonging to the technical field of gelled fuels. The low-molecular mass organic gellant has a cyclopropane structure. The cyclopropane structure belongs to a high-tension structure, which endows the gellant with excellent gel properties; in addition, the high-tension cyclopropane structure is also capable of greatly improving a combustion performance of the gellant, shortening an ignition delay time of the fuel, and promoting combustion. Moreover, multiple hydroxyl groups contained in the low-molecular mass organic gellant is capable of effectively forming a gel through hydrogen bonding; therefore, the gellant has excellent gel and shear thinning properties for high-energy density fuel and energetic nanofluid fuel, with a critical gellant concentration of not greater than 1% when forming a stable gel.

Abstract: An alkaline protease mutant, and a gene, engineered strain, a preparation method and application thereof are provided. The method comprises the following steps of extracting genome DNA of Bacillus clausii, performing PCR amplification to obtain a wild-type alkaline protease gene sequence, mutating the wild-type alkaline protease gene obtained by the amplification through an error-prone PCR, performing high-throughput screening to obtain a plurality of highly active alkaline protease genes, performing DNA shuffling on the highly active alkaline protease genes, and performing screening to obtain eight alkaline protease mutant genes with higher activity.

Abstract: The disclosure relates to etoricoxib solvates and a preparation method thereof. A solvent is a hydrogen bond donor solvent with a polarity value ?* ranging from 60 to 100 or a hydrogen bond acceptor solvent with a polarity value ?* ranging from 92 to 100. Solvents with a polarity value ?* within the above range all can form corresponding etoricoxib solvates with etoricoxib. The etoricoxib solvate can be prepared by cooling crystallization or suspension crystallization. A 1,2-propanediol solvate of etoricoxib and a dimethyl sulfoxide (DMSO) solvate of etoricoxib provided in the present disclosure have high thermal stability, unique crystal form, large size, concentrated distribution, and prominent flowability and is safe, pharmaceutically acceptable, and not easy to agglomerate. Compared with etoricoxib, the etoricoxib solvates exhibit significantly improved solubility.

Abstract: The disclosure discloses a method for preparing biochar from Enteromorpha prolifera and use of the biochar. The method includes: subjecting Enteromorpha prolifera to lyophilization, then impregnating lyophilized Enteromorpha prolifera with phosphoric acid, and drying to a constant weight; grinding a dried mixture in a mortar, and then subjecting a ground sample to activation treatment in a tube furnace at 400° C. to 1,000° C. under a nitrogen atmosphere; and boiling an obtained solid product with concentrated hydrochloric acid, then washing with ultrapure water, and drying to a constant weight to obtain Enteromorpha prolifera biochar. The biochar is used in adsorption of cadmium. The method for removing cadmium using Enteromorpha prolifera biochar provided by the disclosure exhibits an extremely high adsorption and removal capacity for cadmium, with an adsorption capacity of biochar up to 250 mg/g or more.

Abstract: Disclosed is a water circulation intelligent sensing and monitoring system based on differentiable reasoning, including a processor module, wherein a data terminal of the processor module is connected to a feature knowledge base module, an intelligent sensing module and an intelligent control module, respectively; the intelligent sensing module is connected to the feature knowledge base module through a conversion module; the feature knowledge base module includes a differentiable reasoning unit, a feature knowledge base unit and a feature knowledge graph unit; and a data terminal of the feature knowledge graph unit is connected to the differentiable reasoning unit, the feature knowledge base unit and the conversion module.

Abstract: The invention discloses a method for obtaining the geometrical and mechanical parameters of rock samples and a holographic scanning system thereof, wherein the system includes an observation mechanism, a multi-scale penetration mechanism, a grinding mechanism, a rock sample installation mechanism arranged on a three-axis precision motion platform, and an industrial computer controlling the operation mode of each mechanism of the platform Indentation/rotary penetration test, pulse echo signal acquisition, three-dimensional surface topography reconstruction, layer by layer grinding and repeated experiments are carried out. The geometric parameters and corresponding mechanical field parameters are obtained by spatial interpolation of the three-dimensional parameter lattice accumulated by several layers of single-layer rock parameters. The holographic scanning system and method can obtain the real spatial distribution of various media in rock samples.