Abstract: The present invention provides a testing and characterization method for an initial fatigue damage and development process of vulcanized rubber, and falls within the technical field of rubber. The testing and characterization method comprises the following steps: preparing vulcanized rubber; preparing test samples; preparing fatigue testing specimens; and characterizing an initial fatigue damage and development process. The testing and characterization method provided by the present invention is simple, and closely associates a simple and easy-to-implement macro mechanical property test with changes of an internal microstructure, which are difficult to observe and analyze; and the method is high in efficiency and easy for operation and data collection, and data measured has good reference.

Abstract: The embodiments of the present application include acquiring a monitoring region and each observation point therein; partitioning the monitoring region into N layers of grids according to a seismic source positioning accuracy, wherein a side length of a grid cell of an i-th layer of grid is D/2i-1, i=1, . . . N, and D is an initial side length of the grid cell and not more than a double of a distance between the respective observation points; searching all nodes in a first layer of grid to acquire a node satisfying a preset condition therefrom; from i=2, determining and searching nodes satisfying a first preset requirement in the i-th layer of grid, to acquire a node satisfying the preset condition therefrom, until a search in an N-th layer of grid is completed, wherein a node satisfying the preset condition acquired in the N-th layer of grid is a seismic source point location.

Abstract: The embodiments of the present application include acquiring a monitoring region and each observation point therein; partitioning the monitoring region into N layers of grids according to a seismic source positioning accuracy, wherein a side length of a grid cell of an i-th layer of grid is D/2i-1, i=1, . . . N, and D is an initial side length of the grid cell and not more than a double of a distance between the respective observation points; searching all nodes in a first layer of grid to acquire a node satisfying a preset condition therefrom; from i=2, determining and searching nodes satisfying a first preset requirement in the i-th layer of grid, to acquire a node satisfying the preset condition therefrom, until a search in an N-th layer of grid is completed, wherein a node satisfying the preset condition acquired in the N-th layer of grid is a seismic source point location.

Abstract: Three-level inverter and rectifier power conversion systems and space vector modulation (SVM) controls having even-order harmonic elimination for neutral voltage balancing with a predefined vector switching sequences for half-wave symmetry in open loop system operation. The vector sequence listings for each SVM diagram segment includes switching state entries individually indicating one of three possible switching state levels positive (P), zero (0), or negative (N) for each of three or more switching groups of the power conversion system, with listings for each pair of first and second diametrically opposite diagram segments include symmetrically opposite switching states, with positive levels in the entries of the listing for the first segment corresponding to negative levels in the entries of the listing for the second segment and vice versa.

Abstract: AC-to-AC power conversion systems and methods are presented, in which a small number of asymmetrical power switching devices are used to convert input AC power to output AC power of constant or variable frequency.

Abstract: AC-to-AC power conversion systems and methods are presented, in which a small number of asymmetrical power switching devices are used to convert input AC power to output AC power of constant or variable frequency.

Abstract: Three-level inverter and rectifier power conversion systems and space vector modulation (SVM) controls having even-order harmonic elimination for neutral voltage balancing with a predefined vector switching sequences for half-wave symmetry in open loop system operation. The vector sequence listings for each SVM diagram segment includes switching state entries individually indicating one of three possible switching state levels positive (P), zero (0), or negative (N) for each of three or more switching groups of the power conversion system, with listings for each pair of first and second diametrically opposite diagram segments include symmetrically opposite switching states, with positive levels in the entries of the listing for the first segment corresponding to negative levels in the entries of the listing for the second segment and vice versa.