Abstract: A theme classification method based on multimodality is related to a field of a knowledge map. The method includes obtaining text information and non-text information of an object to be classified. The non-text information includes at least one of visual information and audio information. The method also includes determining an entity set of the text information based on a pre-established knowledge base, and then extracting a text feature of the object based on the text information and the entity set. The method also includes determining a theme classification of the object based on the text feature and a non-text feature of the object.

Abstract: A system and a method of black start for a combined operation of wind power, photovoltaic power, energy storage, and thermal power includes a renewable energy alternating current microgrid module, a power transmission and distribution module, and a thermal power generation module, the power transmission and distribution module is coupled to the renewable energy alternating current microgrid module and the thermal power generation module respectively. The renewable energy alternating current microgrid module includes a photovoltaic unit, a wind power unit, and an energy storage unit. The power transmission and distribution module is configured to transmit the electrical energy generated by the renewable energy alternating current microgrid module to the thermal power generation module. The thermal power generation module is configured to start an auxiliary equipment using the electrical energy transmitted by the power transmission and distribution module.

Abstract: The system for frequency modulation based on Direct Current (DC) controllable load for a high-voltage plant includes a frequency modulator and a DC-controllable load for the high-voltage plant connected to the frequency modulator. The frequency modulator includes a centralized rectifier configured to adjust power of loads in the DC-controllable load in response to a frequency modulation command. The DC-controllable load is configured to respond to an adjustment of the power of loads performed by the centralized rectifier.

Abstract: A method of authenticating a client device to access a user account stored on a remote server includes creating the user account based on a blockchain address of a blockchain wallet, transmitting a login request for logging into the user account from the client device to the remote server, and transmitting a random challenge from the remote server to the client device when the remote server receives the transmitted login request. The random challenge is associated with the user account and no other user account. The method further includes signing the random challenge with the client device, the signature based on a private key of the blockchain wallet, transmitting the signed random challenge and the blockchain address to the remote server, and verifying that the signed random challenge corresponds to the transmitted random challenge with the remote server using a public key of the blockchain wallet and the random challenge.

Abstract: A long afterglow luminescent material of the formula aMO.bM? (S?Se1-?).cAl2O3.d B2O3.eP2O5: xEu.yLn, wherein M is/are selected from Sr, Ca, Ba, and Mg, and any combinations thereof; M? is/are selected from Sr, Ca, and Ba, and any combinations thereof; Ln is/are selected from Nd, Dy, Ho, Tm, La, Ce, Er, Pr, Bi, and Sm, and any combinations thereof; a, b, c, d, e, x and y are mole ratios, wherein 0.5<a<6.0, 0.0001?b?2.0, 0.5?c?9.0, 0?d?1.0, 0?e?1.0, 0.00001?x?0.25, 0.00001?y?0.3, 0???1.0, 0.5<(a+b)?6.0, 0<(d+e)?1.0. The preparation process thereof is a high temperature solid-state reaction comprising an oxidation stage and a subsequent reduction stage.

Abstract: A long afterglow luminescent material of the formula aMO.bM? (S?Se1-?).cAl2O3.d B2O3.eP2O5: XEu.yLn, wherein M is/are selected from Sr, Ca, Ba, and Mg, and any combinations thereof; M? is/are selected from Sr, Ca, and Ba, and any combinations thereof; Ln is/are selected from Nd, Dy, Ho, Tm, La, Ce, Er, Pr, Bi, and Sm, and any combinations thereof; a, b, c, d, e, x and y are mole ratios, wherein 0.5<a<6.0, 0.0001?b?2.0, 0.5?c?9.0, 0?d?1.0, 0?e?1.0, 0.00001?x?0.25, 0.00001?y?0.3, 0?P?1.0, 0.5<(a+b)?6.0, 0<(d+e)?1.0. The preparation process thereof is a high temperature solid-state reaction comprising an oxidation stage and a subsequent reduction stage.