Abstract: The present invention discloses a domain wall straightening method of a periodically poled ferroelectric crystal. In the present invention, by testing a piezoelectric coefficient of a poled sample, the poling condition of the sample can be judged nondestructively, and the region of uniform poling can be screened out. At the same time, according to the calculation result of a duty cycle, the continuation or stop of poling, and the re-poling after single domain can be judged. The flatness of the domain wall is judged through the change quantity of the piezoelectric coefficient, and the size and the duration of the poling voltage are adjusted in time, to accurate control the poling process, so as to obtain high-quality periodically poled crystals.

Abstract: The present invention discloses a domain wall straightening method of a periodically poled ferroelectric crystal. In the present invention, by testing a piezoelectric coefficient of a poled sample, the poling condition of the sample can be judged nondestructively, and the region of uniform poling can be screened out. At the same time, according to the calculation result of a duty cycle, the continuation or stop of poling, and the re-poling after single domain can be judged. The flatness of the domain wall is judged through the change quantity of the piezoelectric coefficient, and the size and the duration of the poling voltage are adjusted in time, to accurate control the poling process, so as to obtain high-quality periodically poled crystals.

Abstract: The present invention discloses a device and method for testing the gas loss amount which simulates a wireline coring process, and belongs to the field of petroleum engineering. The device includes: a programmable temperature control thermostat for simulating temperature changes in a wireline coring process, a simulated center pipe body for constructing a simulated environment of the center pipe body being filled with drilling fluid or clean water, a simulated coring barrel for drilling for and retaining a core sample, a gas injection control and recovery device, a liquid injection control and recovery device, and a drainage and gas collection meter.

Abstract: The present invention discloses a device and method for testing the gas loss amount which simulates a wireline coring process, and belongs to the field of petroleum engineering. The device includes: a programmable temperature control thermostat for simulating temperature changes in a wireline coring process, a simulated center pipe body for constructing a simulated environment of the center pipe body being filled with drilling fluid or clean water, a simulated coring barrel for drilling for and retaining a core sample, a gas injection control and recovery device, a liquid injection control and recovery device, and a drainage and gas collection meter.