Abstract: A method for determining lower radius limit of movable throat of shale is provided, and it includes: performing a low-temperature nitrogen adsorption test on a target shale to obtain first pore radii; performing a high-pressure mercury injection test on the target shale to obtain second pore radii; performing a nuclear magnetic resonance test on the target shale to obtain third pore radii; obtaining a relationship diagram of distribution frequencies and pore radii according to three pore radii; distinguishing, according to the pore radii, relationship diagram data, and performing normalization processing to determining a relationship curve of normalized frequency data and the pore radii; and determining a lower radius limit of movable throat of shale according to relationship curve. A problem of describing characteristics of shale occurrence space with complex pore structures and strong heterogeneity is solved, the method is suitable for determining lower radius limit of movable throat of shale.

Abstract: A method for determining lower radius limit of movable throat of shale is provided, and it includes: performing a low-temperature nitrogen adsorption test on a target shale to obtain first pore radii; performing a high-pressure mercury injection test on the target shale to obtain second pore radii; performing a nuclear magnetic resonance test on the target shale to obtain third pore radii; obtaining a relationship diagram of distribution frequencies and pore radii according to three pore radii; distinguishing, according to the pore radii, relationship diagram data, and performing normalization processing to determining a relationship curve of normalized frequency data and the pore radii; and determining a lower radius limit of movable throat of shale according to relationship curve. A problem of describing characteristics of shale occurrence space with complex pore structures and strong heterogeneity is solved, the method is suitable for determining lower radius limit of movable throat of shale.

Abstract: A payment two-dimensional code secure payment method and system without two-step authentication. The method comprises the following steps: by means of a payment application, producing a first payment two-dimensional code and a second payment two-dimensional code, and alternately displaying the first payment two-dimensional code and the second payment two-dimensional code; respectively identifying the first payment two-dimensional code and the second payment two-dimensional code to acquire complete payment information; sending the complete payment information to a payment centre for verification; when verification is successful, the payment is complete. The present method effectively avoids the property loss incurred by users due to scanning of payment two-dimensional code pictures, and increases payment security.

Abstract: A method and system for displaying a security risk value of online payment by a color. The method comprises the following steps: obtaining a risk value parameter of an online payment risk value, and allocating a color channel to each risk value parameter; during payment, calculating a brightness value of each color channel according to payment information; and if the brightness value of the color channel is greater than a set security risk value, carrying out payment early warning. According to the method, a security state of the current online payment is displayed by an obvious color, and a security risk can be prompted and warned before the online payment, thereby improving payment security.

Abstract: A payment two-dimensional code secure payment method and system without two-step authentication. The method comprises the following steps: by means of a payment application, producing a first payment two-dimensional code and a second payment two-dimensional code, and alternately displaying the first payment two-dimensional code and the second payment two-dimensional code; respectively identifying the first payment two-dimensional code and the second payment two-dimensional code to acquire complete payment information; sending the complete payment information to a payment centre for verification; when verification is successful, the payment is complete. The present method effectively avoids the property loss incurred by users due to scanning of payment two-dimensional code pictures, and increases payment security.