Abstract: Implementations of this specification provide methods and apparatuses for replaying logs. One method includes: classifying a plurality of logs to be replayed into log queues, sending the log queues to a global replay queue, allocating one or more replay threads to the log queues based on rankings of the log queues in the global replay queue, wherein the one or more replay threads are configured to replay one or more current log queues of the log queues, and in response to identifying an error of a current log queue of the one or more current log queues in a replay process, allocating a replay thread of the one or more replay threads allocated to the current log queue to a log queue that immediately follows the current log queue in the global replay queue.

Abstract: A network topology generation method includes: obtaining original coordinate information of each topology node in a first topology diagram, where the original coordinate information includes a first coordinate of each topology node in the first topology diagram, and topology nodes in the first topology diagram include a first node, a second node, and a third node; and generating a second topology diagram, where the second topology diagram corresponds to a topology diagram obtained by scaling the first topology diagram, a second coordinate of the second node is obtained using a second coordinate of the first node as a reference point, and a second coordinate of the third node is obtained using the second coordinate of the second node as a reference point.

Abstract: The present disclosure discloses a high-safety ternary positive electrode material and a method for preparing the same; wherein the ternary positive electrode material has a chemical composition of Lia(NixCoyMn1-x-y)1-bMbO2-cAc, wherein 0.75?a?1.2, 0.75?x<1, 0<y?0.15, 1?x?y>0, 0?b?0.01, 0?c?0.2, M is one or more selected from the group consisting of Al, Zr, Ti, Y, Sr, W and Mg, and A is one or more selected from the group consisting of S, F and N; and CMn?(1?x?y)?0.07; CCo?y?0.05; 0?[CMn?(1?x?y)]/(CCo?y)?2.0. The ternary positive electrode material of the present disclosure is a high-nickel single crystal material with gradient concentration; it has the advantages of high capacity and high thermal stability, and the preparation method is simple, and is suitable for large-scale production.

Abstract: A digital microfluidic apparatus and a driving method therefor. The digital microfluidic apparatus comprises a digital microfluidic chip (10), a thermal control apparatus (20), and an elastic support apparatus (30). The digital microfluidic chip (10) is provided with a droplet channel (91), and the droplet channel (91) is configured to allow droplets (90) to move therein; the thermal control apparatus (20) is disposed on one side of the digital microfluidic chip (10), and is configured to generate at least two independent and non-interference hot zones in the droplet channel (91), and control the temperature of each hot zone; and the elastic support apparatus (30) is disposed on the side of the thermal control apparatus (20) away from the digital microfluidic chip (10), and is configured to drive the thermal control apparatus (20) to be pasted on the surface of the digital microfluidic chip (10).

Abstract: The present invention discloses a full-gradient nickel cobalt manganese positive electrode material, a ruthenium oxide coated material and a preparation method thereof. The material has a chemical formula of LiNixCoyMn(1-x-y)O2, wherein, 0.5?x?0.9, 0.05?y?0.40, 1-x-y>0. A content of the nickel element is gradually decreased from a core portion to an outer surface of the full-gradient nickel cobalt manganese positive electrode material. A content of the manganese element is gradually increased from the core portion to the outer surface of the full-gradient nickel cobalt manganese positive electrode material. And, a content of the cobalt element is uniformly distributed in the full-gradient nickel cobalt manganese positive electrode material. The present invention also discloses a preparation method of the full-gradient nickel cobalt manganese positive electrode material. The present invention also discloses a preparation method of the ruthenium oxide coated material.

Abstract: A database query optimization computer-implemented method, medium, and system are disclosed. In one computer-implemented method, a data query request sent by a client device is received and parsed. An execution plan for executing the data query request is determined based on a parsing result. If the execution plan is a nested loop anti-join, whether there is a possibility that a to-be-queried field in a to-be-queried data table indicated by the data query request contains a NULL value is determined. If there is a possibility that the to-be-queried field contains a NULL value, a filter condition is generated and the execution plan is optimized based on the filter condition.

Abstract: A database query optimization computer-implemented method, medium, and system are disclosed. In one computer-implemented method, a data query request sent by a client device is received and parsed. An execution plan for executing the data query request is determined based on a parsing result. If the execution plan is a nested loop anti-join, whether there is a possibility that a to-be-queried field in a to-be-queried data table indicated by the data query request contains a NULL value is determined. If there is a possibility that the to-be-queried field contains a NULL value, a filter condition is generated and the execution plan is optimized based on the filter condition.

Abstract: The present invention discloses a full-gradient nickel cobalt manganese positive electrode material, a ruthenium oxide coated material and a preparation method thereof. The material has a chemical formula of LiNixCoyMn(1-x-y)O2, wherein, 0.5?x?0.9, 0.05?y?0.40, 1-x-y>0. A content of the nickel element is gradually decreased from a core portion to an outer surface of the full-gradient nickel cobalt manganese positive electrode material. A content of the manganese element is gradually increased from the core portion to the outer surface of the full-gradient nickel cobalt manganese positive electrode material. And, a content of the cobalt element is uniformly distributed in the full-gradient nickel cobalt manganese positive electrode material. The present invention also discloses a preparation method of the full-gradient nickel cobalt manganese positive electrode material. The present invention also discloses a preparation method of the ruthenium oxide coated material.