Abstract: Provided are transaminase mutants and uses thereof. The transaminase mutant is obtained by one or more amino acid mutations occurring in SEQ ID NO: 2 or is a mutant with a conserved amino acid mutation obtained by taking the sequence SEQ ID NO: 1 of a wild-type CvTA transaminase as a reference. Compared with wild-type transaminases, the catalytic activity of the mutant is improved to different degrees, so that the production efficiency of chiral amine compound synthesis may be improved.

Abstract: Provided is a two-stage reverse-torque bent screw orientation tool. An existing bent screw orientation technology has the technical problems of large friction resistance, difficult control of a borehole track, a low drilling speed and the like, and restricts economic, safe and long-acting development of oil and gas. In order to solve the above problems, the two-stage reverse-torque bent screw orientation tool is invented and composed of a first-stage clutch mechanism and a second-stage clutch mechanism, and the first-stage clutch mechanism and the second-stage clutch mechanism are both composed of a battery, a battery compartment, a pressure sensor, an electromagnetic valve, a body, a plug, a piston, an outer tooth cylinder, an inner tooth cylinder, a transmission cylinder, a connecting cylinder, a bearing, a limiting cylinder, a lower joint, a thrust bearing, a battery compartment, a circuit board, a cover plate and the like.

Abstract: Provided are an esterase mutant and use thereof. The amino acid sequence of the esterase mutant has a sequence as shown in SEQ ID NO: 1, and sites at which amino acid mutations occur include an N51G site.

Abstract: Disclosed are a wireless remote control method and system for controllable rotary sliding guiding drilling. An upper end of a controllable rotary sliding guiding drilling mechanism is provided with a drill rod; and the wireless remote control system for controllable rotary sliding guiding drilling further comprises: an MWD arranged at a lower end of the controllable rotary sliding guiding drilling mechanism; a bent screw drill tool mounted at a lower end of the MWD; a drill bit mounted at a lower end of the bent screw drill tool, the drill bit being connected with the bent screw drill tool through a connector; and a clutch module mounted on the controllable rotary sliding guiding drilling mechanism, the clutch module comprising an electromagnetic valve, a processor, an internal pipe pressure sensor, an external pipe pressure sensor and a wireless data transmission module.

Abstract: A steam soot blowing device is provided, including: a steam sootblower, a first pipe communicating with the steam sootblower; and nozzle assemblies communicating with the first pipe, including a first nozzle assembly and a second nozzle assembly, wherein the first nozzle assembly includes a throttle pipe with one end communicating with the first pipe, and a sprayer communicating with the other end of the throttle pipe, and diameter of an inlet of the sprayer is smaller than diameter of an outlet thereof; the second nozzle assembly includes a distribution pipe communicating with the first pipe and at least one nozzle communicating with the distribution pipe, wherein steam jet velocity at the outlet of the sprayer is greatly smaller than steam jet velocity at an outlet of the nozzle.

Abstract: A rotary air preheater is provided, including: a rotor and a steam soot-blowing device arranged in a cold secondary air inlet channel of secondary air section. The steam soot-blowing device includes a steam sootblower, a first pipe communicating with the steam sootblower and extending in a radial direction of the rotor, and nozzle assemblies communicating with the first pipe. The nozzle assembly includes a first nozzle assembly and a second nozzle assembly, and the first nozzle assembly is located upstream of the second nozzle assembly in a rotational direction of the rotor. The first nozzle assembly includes a sprayer, and diameter of an inlet of the sprayer is smaller than diameter of an outlet thereof. The second nozzle assembly includes at least one nozzle, and steam jet velocity at the outlet of the sprayer is greatly smaller than steam jet velocity at an outlet of the nozzle.

Abstract: A steam soot blowing device is provided, including: a steam sootblower, a first pipe communicating with the steam sootblower; and nozzle assemblies communicating with the first pipe, including a first nozzle assembly and a second nozzle assembly, wherein the first nozzle assembly includes a throttle pipe with one end communicating with the first pipe, and a sprayer communicating with the other end of the throttle pipe, and diameter of an inlet of the sprayer is smaller than diameter of an outlet thereof; the second nozzle assembly includes a distribution pipe communicating with the first pipe and at least one nozzle communicating with the distribution pipe, wherein steam jet velocity at the outlet of the sprayer is greatly smaller than steam jet velocity at an outlet of the nozzle.

Abstract: A rotary air preheater is provided, including: a rotor and a steam soot-blowing device arranged in a cold secondary air inlet channel of secondary air section. The steam soot-blowing device includes a steam sootblower, a first pipe communicating with the steam sootblower and extending in a radial direction of the rotor, and nozzle assemblies communicating with the first pipe. The nozzle assembly includes a first nozzle assembly and a second nozzle assembly, and the first nozzle assembly is located upstream of the second nozzle assembly in a rotational direction of the rotor. The first nozzle assembly includes a sprayer, and diameter of an inlet of the sprayer is smaller than diameter of an outlet thereof. The second nozzle assembly includes at least one nozzle, and steam jet velocity at the outlet of the sprayer is greatly smaller than steam jet velocity at an outlet of the nozzle.