Abstract: Provided are transaminase mutants and uses thereof. The transaminase mutant is obtained by one or more amino acid mutations occurring in SEQ ID NO: 2 or is a mutant with a conserved amino acid mutation obtained by taking the sequence SEQ ID NO: 1 of a wild-type CvTA transaminase as a reference. Compared with wild-type transaminases, the catalytic activity of the mutant is improved to different degrees, so that the production efficiency of chiral amine compound synthesis may be improved.

Abstract: Disclosed is a microwave chemical method for totally extracting fluorine and rare earth from bastnaesite concentrate, including: alkaline conversion defluorination of bastnaesite through microwave irradiation, microwave-assisted leaching of fluorine, solid-liquid separation of leaching solution and microwave-assisted leaching of rare earth. The rare earth hydrochloric acid solution for leaching contains no fluorine ion, so that the fluorine interference of subsequent processes such as impurity removal can be completely avoided; the fluorine and the rare earth are leached with microwaves, which does not need the stirring, so that the automatic control is easy to implement; the fluorine and rare earth leaching speed is high, the leaching time is short and the complete leaching of fluorine and little residual alkali in the slag can be realized by two-time leaching; and no fluorine-containing waste water is discharged, and the total extraction of the rare earth can be realized by one-time leaching.

Abstract: A delivery guidewire (100), comprising: a core wire (110) comprising a first segment (111), a second segment (112) and a third segment (113), which are arranged in sequence and have diameters decreasing in the direction from a distal end to a proximal end of the delivery guidewire (100); a metal ring (130) at least partially disposed at a proximal end of the first segment (111); and a spring (120) at least partially disposed over the outer side of the second segment (112). A distal end of the spring (120) abuts against a proximal end of the metal ring (130), and a distal section of the spring (120) has a diameter smaller than a diameter of a proximal section thereof. The diameter of the distal section of the spring (120) that is smaller than the diameter of the proximal section of the spring (120) results in a smaller clearance between the distal section of the spring (120) and the core wire (110), which enables greater concentricity of the distal section of the spring (120) with the core wire (110).

Abstract: A display device is disclosed. The display device includes an array substrate and at least two driving units. The array substrate includes a peripheral region and a display region, the array substrate further includes a peripheral grounding line and a test line, wherein the peripheral grounding line is located in the peripheral region, and the test line is located in the peripheral region. The at least two driving units are located on at least one side of the array substrate, the driving unit includes at least two grounding pins, a grounding pin of at least one of the driving units is connected to the peripheral grounding line, and each of at least one grounding pin of one of two adjacent driving units is electrically connected to a corresponding grounding pin of the other adjacent driving unit.

Abstract: A single-stage multi-path direct current access converter and a control method thereof are provided. The single-stage multi-path direct current access converter includes an AC-side conversion circuit; at least two DC-side conversion circuits; and transformers corresponding to the at least two DC-side conversion circuits. AC sides of the at least two DC-side conversion circuits are respectively connected to primary windings of the corresponding transformers; secondary windings of the transformers are connected in parallel to a first side of the AC-side conversion circuit; each of the at least two DC-side conversion circuits is configured to invert DC power received by the DC-side conversion circuit, or to rectify AC power received by the DC-side conversion circuit; and the AC-side conversion circuit is configured to perform AC frequency conversion.

Abstract: An air conditioning system includes a main circuit having a multi-stage compressor, a condenser, a throttling element and an evaporator connected by pipelines; and a cooling branch, the inlet of which is connected to the main circuit between the condenser and the throttling element, and the outlet of which is connected to at least one of the first-stage suction port and the intermediate-stage suction port of the multi-stage compressor, wherein refrigerant from the cooling branch flows through the drive motor of the multi-stage compressor, and a regulating valve for controlling the opening of the cooling branch is provided on the cooling branch; and a control module that controls the opening of the regulating valve on the cooling branch based on the temperature of the outlet downstream of the drive motor on the cooling branch and the intermediate suction pressure of the intermediate-stage suction port of the multi-stage compressor.

Abstract: A writing panel includes an array substrate, a flexible substrate disposed opposite to the array substrate, a liquid crystal layer disposed between the array substrate and the flexible substrate, and a plurality of spacers each in a shape of a column disposed on a surface of the array substrate proximate to the liquid crystal layer. The array substrate includes a base and a pixel driving circuit layer disposed on the base, and the pixel driving circuit layer includes a plurality of thin film transistors and a plurality of signal lines. An orthographic projection of each spacer on the base is non-overlapping with orthographic projections of the plurality of thin film transistors and the plurality of signal lines on the base.

Abstract: Provided are an esterase mutant and use thereof. The amino acid sequence of the esterase mutant has a sequence as shown in SEQ ID NO: 1, and sites at which amino acid mutations occur include an N51G site.

Abstract: The present disclosure provides a composition comprising a compound of formula (I) or a physiologically acceptable salt thereof, in which the compound of formula (I) or a physiologically acceptable salt thereof has a HPLC purity of ?90%; wherein R1, R2, X and n are as defined herein. The present disclosure further provides use of the composition according to the present disclosure for preparing and/or purifying a composition comprising a salt of the compound of formula (I), and a method for treating a disease caused by a Coronavirus which comprises administering the composition of the present disclosure to a subject. The composition of the present disclosure comprises the compound of formula (I) with high purity, and has good fluidity and anti-caking property; moreover, the claimed composition comprising the compound of formula (I)) with high purity is more suitable for preparing a composition comprising a salt of the compound of formula (I) with higher purity.

Abstract: A key-value store and a file system are integrated together to provide improved operations. The key-value store can include a log engine, a hash engine, a sorting engine, and a garbage collection manager. The features of the key-value store can be configured to reduce the number of I/O operations involving the file system, thereby improving read efficiency, reducing write latency, and reducing write amplification issues inherent in the combined key-value store and file system.

Abstract: Embodiments of this specification provide computer-implemented methods, apparatuses, and computer-readable storage media for interface invocation request processing. In an example interface invocation request processing method, an invocation request for a first interface of an operating system is received from a client application, and the first interface is configured to obtain privacy data. First scenario information is obtained, where the first scenario information is description information of a use scenario of the first interface declared when the client application applies for an invocation permission of the first interface. Current scenario information of the client application is obtained. The invocation request is executed in response to at least that the current scenario information matches the first scenario information.

Abstract: Systems and methods are provided for improved point querying of a database. The index values are separated from data and retained in cache memory to allow access without requiring a disk input/output (I/O) operation and thereby having less latency resulting from such disk I/O operations. The index values can be compressed using an algorithm such as Crit-Bit-Trie to allow storage of the index values in limited cache memory space. The index values can be selected for storage according to a least recently used approach when cache memory is insufficient to store all index values to maintain a hit rate for the cached portion and reduce the disk I/O operations.

Abstract: Embodiments of the present disclosure relate to a permission setting method and apparatus, a device, and a medium. The method includes: displaying a permission customization control, in response to a trigger operation on a permission setting object of task information, the permission setting object including a first information object and/or a second information object, the second information object being subordinate to the first information object; displaying a permission editing interface, in response to a trigger operation on the permission customization control, and receiving customization permission information via the permission editing interface; and displaying the customization permission information corresponding to the permission setting object. Therefore, a hierarchy structure based on the task information satisfies a setting need for content-based permission customization, and improves a permission management efficiency.

Abstract: The invention discloses an unmanned surface vessel (USV) formation path-following method based on deep reinforcement learning, which includes USV navigation environment exploration, reward function design, formation pattern keeping, a random braking mechanism and path following, wherein the USV navigation environment exploration is realized adopting simultaneous exploration by multiple underactuated USVs to extract environmental information, the reward function design includes the design of a formation pattern composition and a path following error, the path following controls USVs to move along a preset path by a leader-follower formation control strategy, and path following of all USVs in a formation is realized by constantly updating positions of the USVs.

Abstract: An example apparatus for mining multi-scale hard examples includes a convolutional neural network to receive a mini-batch of sample candidates and generate basic feature maps. The apparatus also includes a feature extractor and combiner to generate concatenated feature maps based on the basic feature maps and extract the concatenated feature maps for each of a plurality of received candidate boxes. The apparatus further includes a sample scorer and miner to score the candidate samples with multi-task loss scores and select candidate samples with multi-task loss scores exceeding a threshold score.

Abstract: A battery includes a battery casing, a first cell, and a second cell. A partition structure is arranged in the battery casing. The first cell is arranged in the battery casing, and at least a part of the first cell is located on a first side of the partition structure. The second cell is arranged in the battery casing, and at least a part of the second cell is located on a second side of the partition structure, and the first side and the second side are oppositely arranged, such that the first cell and the second cell are arranged in a first direction. The partition structure is formed with a communication channel penetrating the first side and the second side.

Abstract: A battery includes an explosion-proof valve and a battery casing. The explosion-proof valve is arranged in the battery casing. The explosion-proof valve includes a first straight line segment, a second straight line segment and a circular arc segment. Two ends of the circular arc segment are respectively connected to the first straight line segment and the second straight line segment. Lengths of the first straight line segment and the second straight line segment are respectively a and b, and an arc length of the circular arc segment is c, a radius of curvature of the circular arc segment is r, and 0.8?a/b?1.2 and 0.5?c/r?2.7 are satisfied.

Abstract: A battery includes a battery casing and an explosion-proof valve. The battery casing includes a first casing member and a second casing member, and the first casing member and the second casing member are welded to form a welded connection region between the first casing member and the second casing member. The welded connection region includes a first region, a second region, and a corner region, and two ends of the corner region are respectively connected to the first region and the second region. The explosion-proof valve is disposed at a corner position of a surface of the first casing member and adjacent to the welded connection region.

Abstract: A free piston generator based on a rigid synchronous transmission system is provided, which belongs to the technical field of power energy. The present disclosure solves the problems of low power generation efficiency and low stability of the existing free piston generator. The free piston generator based on the rigid synchronous transmission system includes a first linear generator set, a second linear generator set, a rigid synchronous transmission assembly, two high-pressure cylinders arranged at two ends of the first linear generator set, and two low-pressure cylinders arranged at two ends of the second linear generator set.

Abstract: The disclosure relates to a method for upgrading firmware of a vehicle infotainment system, a computer-readable storage medium, a mobile terminal, and a vehicle infotainment system. The method for upgrading firmware of a vehicle infotainment system includes the following steps performed by a mobile terminal: receiving a firmware package from a server; performing first security check and first integrity check on the firmware package; if the firmware package passes the first security check and the first integrity check, decompressing the firmware package to obtain a firmware data packet, where the firmware data packet includes a plurality of submodules; performing packing and signing on the plurality of submodules to generate a firmware upgrade package; and sending the firmware upgrade package to a vehicle infotainment system for upgrading.