Abstract: The present application provides a spectral phase interference device and system for addressing the problem of low stability and compactness with prior art spectral phase interference devices. In the device or system provided in the present application, the optical element for generating the pulse pair to be measured consists of only a birefringent crystal and the adjustment of two-step phase shift is also completed by only a broadband quarter-wave plate. Therefore, wide application of optical elements such as pulse stretchers, retarders, optical splitters and mirrors as in prior art devices is avoided, thereby significantly simplifying the overall device's structure and resulting in enhanced stability and compactness at the same time.

Abstract: The present application provides a spectral phase interference device and system for addressing the problem of low stability and compactness with prior art spectral phase interference devices. In the device or system provided in the present application, the optical element for generating the pulse pair to be measured consists of only a birefringent crystal and the adjustment of two-step phase shift is also completed by only a broadband quarter-wave plate. Therefore, wide application of optical elements such as pulse stretchers, retarders, optical splitters and mirrors as in prior art devices is avoided, thereby significantly simplifying the overall device's structure and resulting in enhanced stability and compactness at the same time.

Abstract: A method for predicting valve leakage, comprising following steps: 1) prefabricating a valve; 2) mounting, on the valve, a sensor (70) and a signal transmitter (90); 3) debugging the valve, measuring and determining a critical specific pressure of a sealing face, and preconfiguring the critical specific pressure into the signal transmitter (90); 4) detecting, by the sensor (70), the specific pressure of the sealing face in real time, and transmitting a specific pressure signal to the signal transmitter (90); and 5) comparing, the signal transmitter (90), the detected specific pressure of the sealing face with the critical specific pressure to determine whether the valve is about to leak, i.e., determining that the valve is well sealed and providing no alert when the detected specific pressure of the sealing face is greater than the critical specific pressure.

Abstract: Various embodiments of the present disclosure present unwrapping based B0 mapping systems and methods. An initial B0 map is obtained by unwrapping a pseudo-in-phase complex data that is generated from selected echoes of multi-echo gradient echo image data. Global and local phase errors that are present in the initial B0 map are corrected to produce a phase-error-corrected B0 map. A bias frequency shift is employed to produce a corrected fat-fraction map based on the phase-error-corrected B0 map. The corrected fat-fraction map is employed to generate a final B0 map.

Abstract: Various embodiments of the present disclosure present unwrapping based B0 mapping systems and methods. An initial B0 map is obtained by unwrapping a pseudo-in-phase complex data that is generated from selected echoes of multi-echo gradient echo image data. Global and local phase errors that are present in the initial B0 map are corrected to produce a phase-error-corrected B0 map. A bias frequency shift is employed to produce a corrected fat-fraction map based on the phase-error-corrected B0 map. The corrected fat-fraction map is employed to generate a final B0 map.