Abstract: A line current iM(k0) of an M side of a first direct-current transmission line is collected at a moment k0. A line current iM(k0?ts) thereof is collected at k0?ts. At a moment k0, a differential value diM(k0) of a current of the side of the first direct-current transmission line is calculated according to the line current iM(k0) and the line current iM(k0?ts). It is determined whether the differential value diM(k0) of the current meets a protection enabling criteria. If so, direct-current protection for the M side of the first direct-current transmission line is enabled. A line current iM(j) of the M side of the first direct-current transmission line is collected at a moment j. A line current iM(j?ts) thereof is collected at a moment j?ts. A differential value diM(j) of the current of the M side of the first direct-current transmission line at the moment j is calculated according to the line current iM(j) and the line current iM(j?ts).

Abstract: The present application discloses a cerebral perfusion state classification apparatus and method, a device, and a storage medium. The method includes: acquiring, by a transceiving module, cervical blood flow data from an ultrasound data collecting device; determining, by a processor, cerebral perfusion data corresponding to the cervical blood flow data based on the cervical blood flow data and a mapping relationship between the cervical blood flow data and the cerebral perfusion data, and classifying cerebral perfusion states of a plurality of brain regions based on blood perfusion characteristics of the plurality of brain regions in the cerebral perfusion data.

Abstract: A method and device for timing in time-varying distance protection based on multiple lines of a tower. The method includes: collecting an instantaneous current value at a time-varying distance protection installation location in the multiple lines of the tower, and acquiring preset parameters; calculating, according to the preset parameters and a multi-line ranging model, a multi-line ranging result; calculating, according to the preset parameters, the multi-line ranging result, and an adaptive calculation model, time of a section-II distance protection action and final time of a section-III distance protection action; and determining, according to the instantaneous current value, the preset parameters, and a cross-line failure auxiliary criterion model, final time of the section-II distance protection action.

Abstract: Disclosed are a direct-current transmission line protection method and system based on pure current characteristics.

Abstract: A method and device for timing in time-varying distance protection based on multiple lines of a tower. The method includes: collecting an instantaneous current value at a time-varying distance protection installation location in the multiple lines of the tower, and acquiring preset parameters; calculating, according to the preset parameters and a multi-line ranging model, a multi-line ranging result; calculating, according to the preset parameters, the multi-line ranging result, and an adaptive calculation model, time of a section-II distance protection action and final time of a section-III distance protection action; and determining, according to the instantaneous current value, the preset parameters, and a cross-line failure auxiliary criterion model, final time of the section-II distance protection action.

Abstract: Disclosed are catalyst compositions for isoprene polymerization formed from components comprising (A) at least one titanium halide; (B) at least one organic aluminum compound comprising at least one alkyl aluminum of formula AlR3, wherein each of the three Rs is independently chosen from linear and branched C1-6 alkyl groups; and (C) at least one electron donor comprising at least one polyether compound of formula (I) and/or at least one tetrahydro-furfuryl ether compound of formula (II). Also disclosed are processes for preparation of the catalyst compositions and processes using the catalyst compositions for isoprene polymerization.

Abstract: Disclosed are catalyst compositions for isoprene polymerization formed from components comprising (A) at least one titanium halide; (B) at least one organic aluminum compound comprising at least one alkyl aluminum of formula AlR3, wherein each of the three Rs is independently chosen from linear and branched C1-6 alkyl groups; and (C) at least one electron donor comprising at least one polyether compound of formula (I) and/or at least one tetrahydro-furfuryl ether compound of formula (II). Also disclosed are processes for preparation of the catalyst compositions and processes using the catalyst compositions for isoprene polymerization.