Abstract: Aspects of the disclosure are directed to a method for use on a blockchain network that includes an accounting node subnetwork having accounting nodes configured to record a data block onto a blockchain and a service node having service nodes configured to verify data blocks recorded by the accounting nodes onto the blockchain. The method can include generating a signature based on transaction information to be included in a data block to be added onto the blockchain by using a key specific to the accounting node. The method can further include adding the transaction information and the generated signature to the data block and adding the data block onto the blockchain, and transmitting the signature to the service nodes in the service node subnetwork, so that the service nodes perform signature verification on the signature based on the key specific to the accounting node.

Abstract: This application provide a data management method for a blockchain system, a medium, and an electronic device. The system includes an accounting node sub-network and a service node sub-network. The method includes: adding, after an accounting node generates a first data block, first key information used for verifying a block header of a second data block generated after the first data block to a block header of the first data block; generating a signature corresponding to the first data block, and adding the signature corresponding to the first data block to the block header of the first data block; and releasing the block header of the first data block to the service node sub-network, to cause a service node to verify the signature included in the block header of the first data block, and obtaining the first key information after a successful verification to verify the block header of the second data block.

Abstract: A preparation method for a silver (Ag) and graphitic carbon nitride (g-C3N4) co-modified zinc oxide (ZnO) nanocomposite material using a polymer network gel method includes: dispersing zinc oxide, bulk graphitic carbon nitride, and a soluble silver salt in water to obtain a first solution; adding glucose, a complexing agent, a polymer monomer, and a cross-linking agent into the first solution to obtain a second solution; performing a heating reaction on the second solution to obtain a three-dimensional network wet gel; drying the three-dimensional network wet gel to obtain a dry gel, and calcining the dry gel to obtain the Ag and g-C3N4 co-modified ZnO nanocomposite material. The preparation method has advantages of low cost, short period and simple steps; and the prepared nanocomposite material can be simultaneously applied to photocatalytic degradation of organic dye pollutants and photoexcitation detection of nitrogen dioxide gas at room temperature.

Abstract: A method and an apparatus for security verification of a smart home IoT system under attack. A finite state machine based on the device description information and IFTTT rules, and a formal specification based on a predefined specification template and input parameters, which uses a model verification tool to perform correctness verification regarding whether the finite state machine satisfies the formal specification, and verifies the output counterexample path by the model verification tool to identify the smart home devices and associated IFTTT rules that cause the system insecure. A state parameter of whether a smart home device is under attack is provided for each smart home device when constructing the finite state machine, and an attack intensity parameter is provided for the system when constructing the formal specification.

Abstract: A method and an apparatus for security verification of a smart home IoT system under attack. A finite state machine based on the device description information and IFTTT rules, and a formal specification based on a predefined specification template and input parameters, which uses a model verification tool to perform correctness verification regarding whether the finite state machine satisfies the formal specification, and verifies the output counterexample path by the model verification tool to identify the smart home devices and associated IFTTT rules that cause the system insecure. A state parameter of whether a smart home device is under attack is provided for each smart home device when constructing the finite state machine, and an attack intensity parameter is provided for the system when constructing the formal specification.

Abstract: The present disclosure provides a sample pretreatment reagent for detecting drug in hair, which comprises a hydroxyl group-containing compound which belongs to a reducing agent capable of cleaving disulfide bonds. The disulfide bonds in hair particles are opened to expose the drug molecules embedded in hair gaps, thus improving the release amount of drug molecules from hair without affecting the structure or property of the drug molecules, so that the drug detection limit of the method for detecting drug in hair is reduced, and the drug molecules in a lower content in hair can be detected.