Abstract: Embodiments of the disclosure provide an image processing method and apparatus, a computer-readable medium, and an electronic device. The image processing method includes: extracting a feature map of a target image; dividing the feature map into target regions; determining weights of the target regions according to feature vectors of the target regions; and generating a feature vector of the target image according to the weights of the target regions and the feature vectors of the target regions.

Abstract: A schematic diagram of a wideband measurement system for mixed-connected CVT based on an optical voltage sensor is provided. The wideband measurement system comprises a CVT power frequency measurement section and an optical wideband measurement section. In the optical wideband measurement section, a low-voltage capacitor is connected in series between the low-voltage terminal and the ground terminal of the medium-voltage capacitor in the capacitor voltage divider. An optical voltage sensor is connected in parallel across the terminals of the low-voltage capacitor to measure the wideband voltage signal under test. The wideband measurement system for mixed-connected CVT described in the invention enables the CVT to have wideband measurement capabilities while ensuring the accuracy of conventional CVT power frequency measurements.

Abstract: A nano-emulsion composition having a small particle size and ultra-low concentration and a preparation method thereof is disclosed. The raw materials of the composition comprise, in terms of percentage by weight, 0.002% to 0.2% of a polymer-containing homogeneous microemulsion, water, and 99.998% to 99.8% of an organic salt solution or inorganic salt solution. The composition is prepared by diluting a polymer-containing homogeneous microemulsion with water or a salt solution. The polymer-containing homogeneous microemulsion is formed by mixing the following raw materials, in terms of percentage by weight: 8% to 40% of a surfactant, 0.5% to 10% of a polymer, 10% to 30% of an alcohol, 3% to 30% of an oil, 0% to 20% of a salt, and balance of water. The composition of the invention is low in concentration, low in cost, narrow in particle size distribution, good in stability, simple in preparation, and convenient for storage and use.

Abstract: A nano-emulsion composition having a small particle size and ultra-low concentration and a preparation method thereof is disclosed. The raw materials of the composition comprise, in terms of percentage by weight, 0.002% to 0.2% of a polymer-containing homogeneous microemulsion, water, and 99.998% to 99.8% of an organic salt solution or inorganic salt solution. The composition is prepared by diluting a polymer-containing homogeneous microemulsion with water or a salt solution. The polymer-containing homogeneous microemulsion is formed by mixing the following raw materials, in terms of percentage by weight: 8% to 40% of a surfactant, 0.5% to 10% of a polymer, 10% to 30% of an alcohol, 3% to 30% of an oil, 0% to 20% of a salt, and balance of water. The composition of the invention is low in concentration, low in cost, narrow in particle size distribution, good in stability, simple in preparation, and convenient for storage and use.

Abstract: A liquid pump includes a pump assembly attached to a motor. The pump assembly includes an inlet chamber and pump chamber. The pump chamber accommodates a drive gear driven by an output shaft of the motor and driven gear meshed with the drive gear. An inner cover is disposed within the pump chamber. An outer cover overlies the inner cover with an elastic member disposed there between. The outer cover exerts a force to the inner cover through the elastic member and holds the inner cover in sliding contact with an axial end of the drive and driven gears. An outlet chamber formed between the inner cover and the outer cover is in fluid communication with and the pump chamber.

Abstract: A synthesis method for degradable material(s) (DM) which can be used in oil and gas field operations. The method involves using two, three, four or five polymer and chain extenders, including poly glycolic acid (PGA), polycaprolactone (PCL), polylactic acid (PLA), poly (butylene succinate) (PBS) and poly(3-hydroxybutyrate) (PHA), to synthesize a “resin alloy” through the melt mixing reaction method, which can be used in oil and gas field operations. The proposed DM can be prepared into flake, powder, granules, and ball shapes, or by one of the pure PGA, PCL, PLA, PBS and PHA, into flake, powder, granule and ball shapes, which can be further used in all kinds of operations (drilling, well completion, workover and acidizing fracturing) in oil and gas fields, such as temporary plugging to protect a reservoir, temporary plugging of perforation holes, construction intervals, etc. The DMs are fully degradable and cause almost no damage to formations.

Abstract: A synthesis method for degradable material(s) (DM) which can be used in oil and gas field operations. The method involves using two, three, four or five polymer and chain extenders, including poly glycolic acid (PGA), polycaprolactone (PCL), polylactic acid (PLA), poly (butylene succinate) (PBS) and poly(3-hydroxybutyrate) (PHA), to synthesize a “resin alloy” through the melt mixing reaction method, which can be used in oil and gas field operations. The proposed DM can be prepared into flake, powder, granules, and ball shapes, or by one of the pure PGA, PCL, PLA, PBS and PHA, into flake, powder, granule and ball shapes, which can be further used in all kinds of operations (drilling, well completion, workover and acidizing fracturing) in oil and gas fields, such as temporary plugging to protect a reservoir, temporary plugging of perforation holes, construction intervals, etc. The DMs are fully degradable and cause almost no damage to formations.

Abstract: A liquid pump (10) comprises a pump assembly (14) attached to a motor (12). The pump assembly (14) comprises an inlet chamber (50) and pump chamber (28). The pump chamber (28) accommodates a drive gear (22) driven by an output shaft (16) of the motor (12) and driven gear (26) meshed with the drive gear (22). An inner cover (68) is disposed within the pump chamber (28). An outer cover (20) overlies the inner cover (68) with an elastic member (70) disposed there between. The outer cover (20) exerts a force to the inner cover (68) through the elastic member (70) and holds the inner cover 968) in sliding contact with an axial end of the drive and driven gears (22, 26). An outlet chamber (72) formed between the inner cover (68) and the outer cover (20) is in fluid communication with and the pump chamber (28).