Abstract: A method and a device for data migration of a blockchain. The method includes generating a state tree based on state data of accounts in the blockchain, in which the state tree is a B+ tree based on a copy-on-write technology, and each leaf node of the state tree is configured to store the state data; determining a target state tree to be migrated from the generated state tree when data migration is triggered; sending state data of the target state tree to an extended node of a master node; if migration completion information is received from the extended node, updating a data mapping table stored in the master node, in which the data mapping table is configured to represent a mapping relationship between state data stored in the extended node and the extended node; and deleting the target state tree in the master node.

Abstract: A B+-tree-based data management method includes writing, when a first write operation on a node data of a B+ tree is detected, the node data to a base page of a disk, wherein the base page contains a pointer field configured to indicate an associated delta page; creating a first delta record in a delta page based on the base page, when a first write operation on a target entry in the base page is detected; creating a second delta record in the delta page when a second write operation on the target entry is detected, the second delta record is used to record second data corresponding to the second write operation. Accordingly, a waste of disk space may be reduced, and complexity of read-write operations may be lowered.

Abstract: A method for privacy protection of smart contract includes: obtaining a variable identifier, a privacy-trigger sub-script, and ciphertexts of a plurality of privacy-trigger sub-scripts of other participating users input by the user intending to perform a transaction in response to a transaction instruction; determining a target state variable corresponding to the variable identifier from the smart contract, and obtaining a precomputed ciphertext corresponding to the target state variable; computing, using the preset digest algorithm, based on the plurality of privacy-trigger sub-scripts and the ciphertexts of the plurality of privacy-trigger sub-scripts to obtain the target ciphertext; executing a decision-making script bytecode in the privacy-trigger sub-script to obtain an execution result if the target ciphertext is identical to the precomputed ciphertext; and performing a predetermined operation on the target state variable when the execution result indicates execution success.

Abstract: The present disclosure provides a consensus method and a consensus apparatus for a blockchain system. The consensus method includes: generating a subsequent proposal block by referencing a plurality of proposal blocks and combining current transactions from clients in an (n+x2)-th consensus round; and achieving consensus on the preceding proposal block by using the subsequent proposal block as a certificate for the preceding proposal block. The plurality of proposal blocks are correspondingly generated by the plurality of validation nodes referencing a preceding proposal block in an n-th consensus round, and the preceding proposal block is generated in an (n?x1)-th consensus round. In the consensus method of the present disclosure, there is no need to transmit a large amount of signature messages in the consensus process, and consensus on a specific block is achieved by establishing reference relationships between blocks generated in different consensus rounds.

Abstract: Provided are a consensus method and apparatus for a blockchain, a server and a storage medium. A checkpoint round is designed without waiting for transaction execution results of all nodes in each consensus round so as to reduce the impact of transaction execution on consensus and improve consensus stability. A newly created block comprises an execution result and status of a preorder block of the blockchain. Only the consistency of the newly created block is verified to avoid wasting memory resources and computing resources. The checkpoint round can be customized to improve the scalability of consensus algorithms.

Abstract: The present disclosure discloses a method, device and equipment for actively regulating antenna pointing under the influence of environmental factors, and relates to the technical field of antenna performance regulation.

Abstract: An internal combustion engine with an external circulation system and a working method thereof are provided. The internal combustion engine is externally connected to the external circulation system through an intake port and an exhaust port. The external circulation system is capable of operating in a circulating manner when the internal combustion engine is not running, a significant raise in intake temperature is achieved during intake heating or exhaust heating, thereby the cold start-up performance of the internal combustion engine is improved and harmful emissions during cold start-up is reduced, and a compression ignition working mode of a low compression ratio engine is facilitated to be achieved.

Abstract: A solvent-free adhesion-promoting chain extender, a preparation method therefor, and an application thereof are disclosed. The method includes the following steps: mixing an aromatic vinyl monomer, an acrylate-based monomer, an initiator, and water, then heating the mixture for polymerization, and subjecting the product to a secondary reaction by a twin-screen extruder for granulation, to prepare the extender. The obtained epoxy functionalized chain extender can be applied to a recycled material of a polyester structure and can be used for the repair and growth of molecular chains of biobased and biodegradable plastics of a polyester structure. The method features no use of a solvent in a process route, low investment, easily available apparatuses, low emission in the process route, and simple process control; in addition, the product has stable composition and is easy to use, and thus can be widely used, such as medical treatment, packaging, home appliances, automobiles, and aviation.

Abstract: An internal combustion engine with an external circulation system and a working method thereof are provided. The internal combustion engine is externally connected to the external circulation system through an intake port and an exhaust port. The external circulation system is capable of operating in a circulating manner when the internal combustion engine is not running, a significant raise in intake temperature is achieved during intake heating or exhaust heating, thereby the cold start-up performance of the internal combustion engine is improved and harmful emissions during cold start-up is reduced, and a compression ignition working mode of a low compression ratio engine is facilitated to be achieved.

Abstract: The present invention discloses a high-stiffness high-toughness fully-degradable resin composition. The composition includes the following raw material components in parts by weight: 60-80 parts of PBAT; 10-30 parts of PLA; 5-15 parts of a calcium carbonate whisker; 0.3-0.6 parts of a high molecular weight chain extension compatilizer; 0.01-0.1 parts of a coupling agent; and other processing aids. A preparation method includes: treating a calcium carbonate whisker with a coupling agent, then mixing same with PBAT followed by extrusion and granulation by using a double-screw extruder to obtain a calcium carbonate whisker masterbatch; and then premixing the calcium carbonate whisker masterbatch, PLA, a high molecular weight chain extension compatilizer and an auxiliary agent, followed by melt extrusion and granulation to obtain a high-stiffness high-toughness fully-degradable PBAT/PLA resin composition.

Abstract: A method for active failure recovery of a single node improved based on PBFT algorithm is disclosed. The abnormal node first initiates a view change request, if (2f+1) view change requests containing the same view value cannot be received within a specified period of time, the abnormal node enters a state to be recovered, and the node to be recovered initiates a recovery request to all nodes of the whole network, waits for replies from normal nodes and counts the number of replies, calculates a height of stable checkpoint of the whole network after receiving replies contain the same view value from (2f+1) nodes, and update the state thereof to finally complete the recovery. This method solves an inherent problem in the PBFT algorithm that a failure in a single node cannot be recovered autonomously, so that a practicability of the PBFT algorithm is greatly improved.

Abstract: Provided are a consensus method and apparatus for a blockchain, a server and a storage medium. A checkpoint round is designed without waiting for transaction execution results of all nodes in each consensus round so as to reduce the impact of transaction execution on consensus and improve consensus stability. A newly created block comprises an execution result and status of a preorder block of the blockchain. Only the consistency of the newly created block is verified to avoid wasting memory resources and computing resources. The checkpoint round can be customized to improve the scalability of consensus algorithms.

Abstract: A method for active failure recovery of a single node improved based on PBFT algorithm is disclosed. The abnormal node first initiates a view change request, if (2f+1) view change requests containing the same view value cannot be received within a specified period of time, the abnormal node enters a state to be recovered, and the node to be recovered initiates a recovery request to all nodes of the whole network, waits for replies from normal nodes and counts the number of replies, calculates a height of stable checkpoint of the whole network after receiving replies contain the same view value from (2f+1) nodes, and update the state thereof to finally complete the recovery. This method solves an inherent problem in the PBFT algorithm that a failure in a single node cannot be recovered autonomously, so that a practicability of the PBFT algorithm is greatly improved.

Abstract: A solvent-free adhesion-promoting chain extender, a preparation method therefor, and an application thereof are disclosed. The method includes the following steps: mixing an aromatic vinyl monomer, an acrylate-based monomer, an initiator, and water, then heating the mixture for polymerization, and subjecting the product to a secondary reaction by a twin-screen extruder for granulation, to prepare the extender. The obtained epoxy functionalized chain extender can be applied to a recycled material of a polyester structure and can be used for the repair and growth of molecular chains of biobased and biodegradable plastics of a polyester structure. The method features no use of a solvent in a process route, low investment, easily available apparatuses, low emission in the process route, and simple process control; in addition, the product has stable composition and is easy to use, and thus can be widely used, such as medical treatment, packaging, home appliances, automobiles, and aviation.

Abstract: Provided by the present invention is a high melt strength styrene resin composition. The composition includes the following components proportioned according to certain parts by weight: a styrene resin or a styrene alloy, a tackifier, an antioxidant and a lubricant. Compared to the existing technology, the present invention has the following beneficial effects: 1. a random copolymer used as the tackifier in the present invention is thermodynamically compatible with the styrene resin and the alloy thereof, does not experience phase separation, and has excellent mechanical properties; 2. the random copolymer used as the tackifier in the present invention has a moderate molecular weight, and is more easily plasticized than a rubber powder, a SAN powder having a high molecular weight, a heat-resistant powder, and so on, thus having better processability, uniform thickness, and low shrinkage rate, and not frequently experiencing the problem of surface defects.

Abstract: A probing apparatus includes a carrier having an opening, a supporter disposed on the carrier in a way that its bottom surface faces toward the carrier, its top surface for disposition of a wafer, and its light permeable portion allowing light to pass through the top and bottom surfaces corresponding in position to the opening, an air heating device having a covering plate and an air supply unit, and a probing device having a probe protruding out of the bottom surface of the air heating device. A thermal air source provides thermal air to a heating space between the bottom surface of the air heating device and the top surface of the supporter through an air supply passage of the air supply unit. The probing apparatus can test light emitting efficiency of a light emitting chip in the wafer and heat the chip at the same time.

Abstract: A probing apparatus includes a carrier having an opening, a supporter disposed on the carrier in a way that its bottom surface faces toward the carrier, its top surface for disposition of a wafer, and its light permeable portion allowing light to pass through the top and bottom surfaces corresponding in position to the opening, an air heating device having a covering plate and an air supply unit, and a probing device having a probe protruding out of the bottom surface of the air heating device. A thermal air source provides thermal air to a heating space between the bottom surface of the air heating device and the top surface of the supporter through an air supply passage of the air supply unit. The probing apparatus can test light emitting efficiency of a light emitting chip in the wafer and heat the chip at the same time.

Abstract: Embodiments of the invention relate to a mixed bacteria producing surfactant and its screening method. According to at least one embodiment, there is provided a mixed bacteria producing biosurfactant composed of three kinds of strains: Pseudomonas stutzeri with preservation No. CCTCC AB 205091, Nocardioides ginsengagri with preservation No. CCTCC S2013441, and Bacillus licheniformis with preservation No. CCTCC AB 205141. The mixed bacteria is obtained by choosing the bacterial strain for oil production awaiting screening, activating and culturing it, getting the fermentation liquid in primary screen with blood plate method, and re-screening fermentation liquid in primary screen with oil drain method. This mixed bacteria synthesizes the advantages of the three strain, thus producing a biosurfactant to enhance oil recovery in the oilfield.

Abstract: Systems and methods for liquid flow sensing and control for use with a variety of different types of liquid flow measurement and control systems. The liquid flow sensor system senses a flow signal indicative of the flow rate of the liquid flowing in a sensor conduit and analyzes the flow signal to determine, by detecting characteristic changes in the signal, whether a bubble is present in the sensor conduit. Where the system determines that a bubble is present, it may generate an alarm signal indicative of the presence of the bubble. A flow control system incorporating the flow sensor as a feedback source may respond to the detection of a bubble by temporarily freezing the flow control parameters until the bubble has exited the sensor conduit. The flow control system can implement procedures for clearing a bubble from the sensor conduit where the system detects that the bubble has become stuck.

Abstract: Systems and methods for liquid flow sensing and control for use with a variety of different types of liquid flow measurement and control systems. The liquid flow sensor system senses a flow signal indicative of the flow rate of the liquid flowing in a sensor conduit and analyzes the flow signal to determine, by detecting characteristic changes in the signal, whether a bubble is present in the sensor conduit. Where the system determines that a bubble is present, it may generate an alarm signal indicative of the presence of the bubble. A flow control system incorporating the flow sensor as a feedback source may respond to the detection of a bubble by temporarily freezing the flow control parameters until the bubble has exited the sensor conduit. The flow control system can implement procedures for clearing a bubble from the sensor conduit where the system detects that the bubble has become stuck.