Abstract: A probability multiply-sum structural damage imaging positioning method and system based on a delay factor includes obtaining optimal excitation frequency and group-velocity theoretical correction function based on numerical simulation of composite laminates; based on optimal excitation frequency, obtaining ultrasonic guided wave response signals of composite laminates in healthy and lossy states and sensor coordinates used for signal collection; performing path screening based on ultrasonic guided wave response signals; obtaining group-velocity correction function based on measured group velocity obtained based on ultrasonic guided wave response signal in healthy state, and calculating actual delay time based on obtained effective path, group-velocity correction function, and sensor coordinates; obtaining damage delay factor based on actual and reference delay time; forming path probability distribution based on damage delay factor, and performing path probability multiply-sum operation to obtain structural

Abstract: A digital, self-diagnosis, sensing intelligent layer integrating active and passive monitoring, including: a capacitance testing unit, configured to charge a to-be-tested piezoelectric transducer by generating a step signal, and determine a transition moment, to obtain a free capacitance value of the to-be-tested piezoelectric transducer; a frequency testing unit, to charge the to-be-tested piezoelectric transducer by generating sinusoidal signals of different frequencies, and detect a resonant frequency according to the transition moment; an active and passive monitoring module, to obtain analog response signals in an active mode and a passive mode, and convert the analog response signals into digital response signals for transmission; and a main control module, to transmit a self-diagnosis result and the digital response signals to a guided wave host. The intelligent layer integrates active damage scanning and passive impact monitoring while implementing self-diagnosis for a piezoelectric transducer state.

Abstract: Systems and methods for processing shipment request by using a multi-carrier shipping services platform.

Abstract: Systems and methods for processing shipment request by using a multi-carrier shipping services platform.

Abstract: Systems and methods for processing shipment request by using a multi-carrier shipping services platform.

Abstract: Systems and methods for processing shipment request by using a multi-carrier shipping services platform.

Abstract: Systems and methods for processing shipment request by using a multi-carrier shipping services platform.

Abstract: The invention discloses three-dimensional focusing induced polarization equipment for advance geological prediction of a water inrush disaster source in underground engineering, comprising a constant-current multiplex transmitter, an intelligent multichannel receiver, an automatic multi-electrode switch, an industrial personal computer, an observation electrode array and shielding electrodes, wherein electrodes in the observation electrode array are respectively used as a source electrode and observation electrodes; the industrial personal computer controls the constant-current multiplex transmitter to transmit currents of the same polarity to the shielding electrodes and the source electrode, so that the currents of the source electrodes are nearly directed straight ahead of a driving face under the action of the shielding electrodes; the observation electrodes are used for scanning data acquisition, and the data are fed back to the industrial personal computer through the intelligent multi-channel receiver;

Abstract: The invention discloses three-dimensional focusing induced polarization equipment for advance geological prediction of a water inrush disaster source in underground engineering, comprising a constant-current multiplex transmitter, an intelligent multichannel receiver, an automatic multi-electrode switch, an industrial personal computer, an observation electrode array and shielding electrodes, wherein electrodes in the observation electrode array are respectively used as a source electrode and observation electrodes; the industrial personal computer controls the constant-current multiplex transmitter to transmit currents of the same polarity to the shielding electrodes and the source electrode, so that the currents of the source electrodes are nearly directed straight ahead of a driving face under the action of the shielding electrodes; the observation electrodes are used for scanning data acquisition, and the data are fed back to the industrial personal computer through the intelligent multi-channel receiver;