Abstract: A power conversion device includes two input terminals, a first converter, and two first output terminals configured to output power converted by the first converter. The first converter includes a switching circuit, a flying capacitor, and a reactor. The power conversion device includes a second converter configured to perform power conversion on a voltage across the flying capacitor as an input voltage, two second converter input terminals electrically connected to two ends of the flying capacitor, and two second output terminals configured to output power converted by the second converter. The second converter includes a primary-side circuit and a secondary-side circuit. The second converter is an isolated DC/DC converter in which the primary-side circuit and the secondary-side circuit are electrically isolated from each other.

Abstract: The provided are a device and method for measuring a bonding strength between a contaminated rock surface and a solidified material. The device includes a fixing and measuring assembly and four rock slabs enclosing a rectangular prism, where outer surfaces of the four rock slabs are fitted to two transverse support plates and two longitudinal support plates, respectively; the two longitudinal support plates are arranged between the two transverse support plates; upper and lower ends of the rock slabs are provided with an upper cover and a bottom plate, respectively; the upper cover and the bottom plate are detachably fixed to the two transverse support plates, respectively; the two transverse support plates are detachably fixed to each other through a second screw; a hydraulic device is provided among the four posts; and a movable end of the hydraulic device is provided with a supporting airbag.

Abstract: A lipid compound and a preparation method therefor, and a use thereof are provided. The lipid compound is safe, efficient and ionizable and the structure of the lipid compound is divided into a hydrophilic amino group, a linking group, and a hydrophobic alkyl group. The preparation method of the lipid compound is simple, green and efficient. The lipid compound can be widely used in preparation of a drug carrier.

Abstract: A Kriging model-based optimal design method and device for a bulk acoustic resonator, and a storage medium are provided. The Kriging model-based optimal design method includes: determining a structure and a material of a resonator, establishing a corresponding MASON model, and performing one-dimensional simulation on the MASON model to obtain a simulation result; determining, based on the simulation result, a design variable for optimizing the resonator, and constructing a Kriging surrogate model; determining an optimization goal, constructing an optimization problem model based on the optimization goal and the Kriging surrogate model, and solving the optimization problem model to obtain an optimal solution; and reducing upper and lower limits of the design variable to improve optimization accuracy.

Abstract: Provided are a high-plasticity dual-phase high-entropy alloy (HEA) and a preparation method thereof. The high-plasticity dual-phase HEA has a chemical formula as shown in Formula I: (FeCoNiCr)100-xTix (Formula I), in which, x is in a range of 2.0 to 2.8. A method for preparing the high-plasticity dual-phase HEA is also provided.

Abstract: Provided are a lipid compound, a composition containing the same and use. The lipid compound is prepared by a ring-opening reaction of an organic amine and glycidyl ester and does not structurally contain free amino. The lipid compound can be ionized into a cationic compound under acidic conditions and is bonded to a negatively charged active pharmaceutical ingredient through electrostatic interaction, thereby being assembled into a drug-loaded lipid nanoparticle for delivery of the active pharmaceutical ingredient. The lipid compound provided by the present invention has a simple structure, a simple reaction path and a high yield. The constructed drug-loaded lipid nanoparticle can be used for preparing nucleic acid drugs, genetic vaccines, polypeptide or protein drugs, and small molecule drugs, and has a broad application prospect.

Abstract: Disclosed are a tungsten hexafluoride preparation method and apparatus based on photoelectric synergy. A photocatalyst and metal tungsten are sequentially filled in a discharge area of a plasma reactor in a direction of gas entry, and the discharge area of the plasma reactor is irradiated with light at the same time; the background gas generates a large amount of plasma in the discharge area, SF6 undergoes decomposition under the synergistic effect of photocatalysis and plasma, SF6 is decomposed to generate fluorine atoms and low-fluorine sulfides such as SF5 and SF4. The generated fluorine ions, SF5, SF4 and low-fluorine sulfides further react with metal tungsten to generate WF6 specialty gas, which not only realizes the utilization of fluorine resources of SF6, but also replaces highly toxic fluorine gas with non-toxic SF6 exhaust gas in the plasma reactor for reaction, thereby ensuring safe operation and low energy consumption.

Abstract: The disclosure relates to the field of micro-nano structure-enhanced heat transfer surfaces and provides a 3D printing-assisted multi-scale metal three-dimensional surface structure preparation method and product. The method includes the following steps. A micron-level and highly-precise three-dimensional structure mask is prepared through a 3D printing technology, the hollow portion of mask is matched with the target structure model. Material conversion is performed on a metal matrix fixed with the mask, and a target metal is obtained. Herein, the metal matrix is machined first, and a surface of the target metal is matched with the structure model. In the preparation method provided in the disclosed embodiment, the precision of the metal structure is improved by improving the precision of the template.

Abstract: A multi-label electrocardiogram (ECG) signal classification method based on an improved attention mechanism is provided. A model is constructed for classifying a multi-label (multi-lead) ECG signal. The model has a strong ECG data learning ability, allowing a computer to fully extract a feature of the ECG signal and construct a data processing channel model. Therefore, the multi-label (multi-lead) ECG signal can be effectively classified, improving the accuracy and precision of classification.

Abstract: The present invention relates to a prefabricated infilled panel-frame structure capable of accommodating seismic-loading and seismic energy dissipation, and a construction method thereof, including a frame body, a prefabricated infilled panel group, a panel connector, and a disc spring assembly. During an earthquake, the present invention slides to dissipate energy only after the maximum starting sliding force is exceeded, thus providing the structure with a relatively high lateral stiffness prior to sliding. After an earthquake, the disc spring assembly of the present invention may provide a certain restoring force due to being compressed so as to reduce the residual displacement. Further, the present invention achieves the bidirectional deformation cooperation of the prefabricated infilled panel under earthquakes, so that the infilled panel may still achieve the function of seismic energy dissipation under the coupling action of in-plane and out-of-plane loads.

Abstract: The present invention provides a hypersonic large internal contraction ratio air inlet channel having stepless adjustable air release valve, including an air inlet channel front body, an air-discharging slit cover plate, sidewalls, a lip cover, air-discharging cavities, valve plates, partition plates, a rotatable shaft, an expansion section and a driver. The valve plates are rotated through the driver according to the actual working conditions of air inlet channel, the minimum cross-section of the air discharging flow path is thus changed, and a stepless dynamic adjustment of the air discharging flow of the air inlet channel can be realized, so that the aerodynamic performance of the air inlet channel is improved, and the air discharging resistance of the air vehicle is reduced.

Abstract: The invention provides for delivery, engineering and optimization of systems, methods, and compositions for manipulation of sequences and/or activities of target sequences. Provided are delivery systems and tissues or organ which are targeted as sites for delivery. Also provided are vectors and vector systems some of which encode one or more components of a CRISPR complex, as well as methods for the design and use of such vectors. Also provided are methods of directing CRISPR complex formation in eukaryotic cells to ensure enhanced specificity for target recognition and avoidance of toxicity and to edit or modify a target site in a genomic locus of interest to alter or improve the status of a disease or a condition.

Abstract: Methods for the early sensing of tissue ischemia and/or infarctions within organs using the spectroscopic features of serum luminescence include (i) isolating serum from a blood sample, (ii) directing an excitation light at the serum, (iii) receiving an endogenous serum chromophore emission light from the excited serum, and (iv) determining a presence of an ischemic condition based on the intensity of the endogenous serum chromophore emission light. Methods of detecting organ dysfunction can include transmitting excitation light to luminal contents of a mammalian blood vessel comprising trace amounts of exogenous chromophores administered to the subject mammal via the circulatory system. Transdermal luminescence measurements from the trace amounts of exogenous chromophores can then be used to determine organ dysfunction.

Abstract: The present invention provides a method for designing a strong column and weak beam of a steel frame beam-box column under bidirectional earthquake actions, including the following steps: designing an initial frame; defining important beam-column joints and important sections at a designed axial compression ratio according to a calculated result of a response spectrum CQC method of the initial frame; unifying bidirectional COF values of the important beam-column joints; determining a degree to achieve the strong column and weak beam and proposing two quantifiable evaluation indexes P1 and P2; performing statistics on a damage index D of the frame after an elastic-plastic time-history analysis of a plurality of selected groups of natural waves, and acquiring a parameter frame meeting a target yield mechanism via the statistics performed on the damage index D in combination with an evaluation standard provided by the present invention.

Abstract: Some embodiments of the disclosure provide methods for calculating carbon footprints of leather chemical materials. In some examples, the method includes: determining a calculation range of a carbon footprint of a leather chemical material in a life cycle as “cradle to gate”; determining a system boundary, a functional unit, and cut-off criteria for the carbon footprint of the leather chemical material in the life cycle; dividing the carbon footprint into a raw chemical obtaining process, a production process of the leather chemical material, and a waste disposal process within the system boundary; determining a carbon footprint calculation model for the leather chemical material according to resource consumption and environmental emission of each process; collecting and determining a quantity and a value required by each parameter in the carbon footprint calculation model; and calculating the carbon footprint of the leather chemical material using the carbon footprint calculation model.

Abstract: A computer includes a processor and a memory, and the memory stores instructions executable by the processor to generate a set of points from a measurement scan obtained by a lidar sensor and to generate an expected termination distance of the set of points based on a neural implicit representation of the set of points. The instructions may additionally be to compute a loss function that includes a relatively low margin correlated with the variance or standard deviation of a training distribution centered at a learned point of the set of points based on the expected termination distance of the learned point, the learned point being learned by the neural implicit representation. The instructions may additionally be to generate a keyframe from the set of points and to generate a pose of the lidar sensor based on the keyframe.

Abstract: A Q-switch structure including a solid-state laser medium and a magneto-optical material. The solid-state laser medium and the magneto-optical material are joined and integrated, a first anti-reflecting film for adhesive is formed on a surface of the solid-state laser medium, and a second anti-reflecting film for adhesive is formed on a surface of the magneto-optical material. The first anti-reflecting film for adhesive on the solid-state laser medium and the second anti-reflecting film for adhesive on the magneto-optical material are bonded via a translucent material having a transparency at a laser oscillation wavelength of laser oscillated from the solid-state laser medium. This provides the Q-switch that contributes to the miniaturization of a laser apparatus and has high beam quality.

Abstract: Provided in the present invention are a dynamic collection device for an oil film and temperature distribution in a grinding zone and an operating method thereof. A spectroscope and a 45-degree flat mirror are utilized to carry out optical imaging of the permeation and infiltration of the grinding fluid in a grinding zone during a grinding process, and a video signal imported into a high-speed camera is converted into a digital signal processed by a CCD photosensitive element, and a dynamic image is imported for dynamic collection. Infrared radiation emitted from the grinding zone is reflected through the 45-degree flat mirror, and transmitted to the thermal imaging camera, and the signal is transmitted to an internal infrared detector. The infrared detector adjusts and amplifies the received signal and outputs it to an infrared thermal imaging chip. After image processing, the temperature distribution image is imported for dynamic collection.

Abstract: A building construction robot is provided. The building construction robot includes a vehicle body, a feeding assembly is arranged in the vehicle body, a mounting frame is fixedly connected to one end of the vehicle body, and the mounting frame is located at a discharge end close to the feeding assembly. One end of a vibrating assembly is fixedly connected to one end of a top of the vehicle body, and the other end of the vibrating assembly passes through a middle part of the mounting frame. A leveling assembly is arranged at one end, away from the vehicle body, of the mounting frame, a measuring part is arranged at a top of the mounting frame, and a moving part is arranged at a bottom of the vehicle body.

Abstract: The preset invention provides an energy-saving process and device for recovering C2 from refinery dry gas. The process is as follows: dry gas is cooled and then sent to a multi-stage absorption tower for treatment; the gas phase from the multi-stage absorption tower is sent to a fuel gas pipeline network or PSA unit, and the liquid phase is sent to a high-pressure flash zone for treatment; the gas phase from the high-pressure flash zone is returned to a compression section of a dry gas pretreatment system; the gas phase from the low-pressure flash zone is sent to a C2 concentrated gas compressor system; and the gas phase from the desorption tower is mixed with the gas phase obtained from the low-pressure flash zone and sent to an ethylene cracking furnace as a C2 concentrated gas product, most of the liquid phase is returned to the multi-stage absorption tower.