Abstract: The present disclosure discloses a time service and positioning network system for an underground chain-shaped large space in a coal mine. The system adopts a base station-level network internal time synchronization method which takes an optical fiber time service as a main part and takes a satellite time service as an auxiliary part to construct a time service and positioning network system with an unified time within the ad-hoc network base stations, based on the ad-hoc network base stations linearly arranged in the underground chain-shaped large space in the coal mine. Through the network construction, the network stabilization and the network application, the system unifies the time reference of the base station-level network and improves the positioning accuracy of the network application by utilization of the base station-level network internal time synchronization method.

Abstract: The present disclosure discloses a time service and positioning network system for an underground chain-shaped large space in a coal mine. The system adopts a base station-level network internal time synchronization method which takes an optical fiber time service as a main part and takes a satellite time service as an auxiliary part to construct a time service and positioning network system with an unified time within the ad-hoc network base stations, based on the ad-hoc network base stations linearly arranged in the underground chain-shaped large space in the coal mine. Through the network construction, the network stabilization and the network application, the system unifies the time reference of the base station-level network and improves the positioning accuracy of the network application by utilization of the base station-level network internal time synchronization method.

Abstract: A preparation method of original dye of Vat Brown R comprises the following steps: a. after acylation of 1,5-diaminoanthraquinone, 1-amino-5-benzamidoanthraquinone was prepared by acidic hydrolysis; b. 1-benzamido-4-bromoanthraquinone was obtained from 1-aminoanthraquinone by acylation and bromination; c. a condensate of Vat Brown R was obtained by condensation reaction of 1-amino-5-benzamidoanthraquinone and 1-benzamido-4-bromoanthraquinone; d. the original dye of Vat Brown R was obtained from the condensate of Vat Brown R by ring closing reaction and oxidation reaction. The method omits one oxidation step, economizes significant amount of oxidizing agent, and reduces significant amount of waste water, so it is very beneficial to environment protection; and the method also exhibited the advantages of highly increasing product yield and reducing the costs of raw materials to an extent of more than 30%.