Abstract: The present disclosure relates to the technical field of drug synthesis, in particular to a method for preparing lornoxicam. The method includes the following steps: using 6-chloro-4-hydroxy-2-methyl-2-H-thieno[2,3-e]-1,2-thiazine methyl carboxylate-1,1-dioxide and 2-aminopyridine as raw materials, and xylene as a solvent; mixing the raw material and solvent, and adding a stabilizer, to obtain a mixture; subjecting the mixture to an ammonolysis; cooling the resulting reactant; conducting a vacuum concentration to remove the solvent; adding an organic solvent and slurrying, and filtering, to obtain a crude lornoxicam; and refining the crude lornoxicam to obtain the lornoxicam. In the present disclosure, p-toluenesulfonic acid is used as a stabilizer to reduce the reaction temperature and promote the reaction to proceed forward, thereby improving the quality and yield of the product.

Abstract: Methods for counting synchronization (SYN) packets to identify a SYN attack, applicable to network device, are provided. The network device includes a field programmable gate array (FPGA) for counting the total number of received SYN packets and a high-speed hardware memory connected to the FPGA. One of the methods includes: periodically traversing the count entries stored in the high-speed hardware memory, and aging any count entry for which a time difference between a current time and a creation time reaches a preset aging time interval; obtaining a first number of SYN packets and a second number of SYN packets; and updating the total number of the received SYN packets with a sum of the first number of SYN packets and the second number of SYN packets.

Abstract: The present disclosure relates to the technical field of drug synthesis, in particular to a method for preparing lornoxicam. The method includes the following steps: using 6-chloro-4-hydroxy-2-methyl-2-H-thieno[2,3-e]-1,2-thiazine methyl carboxylate-1,1-dioxide and 2-aminopyridine as raw materials, and xylene as a solvent; mixing the raw material and solvent, and adding a stabilizer, to obtain a mixture; subjecting the mixture to an ammonolysis; cooling the resulting reactant; conducting a vacuum concentration to remove the solvent; adding an organic solvent and slurrying, and filtering, to obtain a crude lornoxicam; and refining the crude lornoxicam to obtain the lornoxicam. In the present disclosure, p-toluenesulfonic acid is used as a stabilizer to reduce the reaction temperature and promote the reaction to proceed forward, thereby improving the quality and yield of the product.

Abstract: Methods for counting synchronization (SYN) packets to identify a SYN attack, applicable to network device, are provided. The network device includes a field programmable gate array (FPGA) for counting the total number of received SYN packets and a high-speed hardware memory connected to the FPGA. One of the methods includes: periodically traversing the count entries stored in the high-speed hardware memory, and aging any count entry for which a time difference between a current time and a creation time reaches a preset aging time interval; obtaining a first number of SYN packets and a second number of SYN packets; and updating the total number of the received SYN packets with a sum of the first number of SYN packets and the second number of SYN packets.