Abstract: A UV/O3/H2O2 advanced oxidation reactor includes a water inlet pipe, a water outlet pipe, an ultraviolet reactor, an H2O2 adding device and an O3 adding device. The ultraviolet reactor has a plurality of ultraviolet lamps embedded therein, and the ultraviolet lamps are arranged at an angle with respect to partition plates. The water inlet pipe is connected to a water inlet in a lower portion of the ultraviolet reactor, and the water outlet pipe is connected to a water outlet in an upper portion of the ultraviolet reactor. The H2O2 adding device and the O3 adding device are arranged on a connecting pipe of the water inlet pipe. After raw water is pressurized, H2O2 is added into the raw water through the H2O2 adding device, then ozone is added in the raw water through a water injector, and finally the raw water enters the ultraviolet reactor.

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 method for synthesizing a chiral amine compound. A transaminase is used to transaminate a ketone substrate under the action of an amino donor, to obtain the chiral amine compound; and the conserved amino acid sequence region of the transaminase at least includes a region 1 (MAGLWCVN) and a region 2 (YNTFFKT). With the transaminase with the specific conserved amino acid sequence region to synthesize a large sterically hindered chiral amine, the enzyme catalytic reaction volume is small, the synthesizing route is short, the product yield is high, a high-cost noble metal is not required for catalysis under the synthesizing conditions, three wastes are reduced, and the production cost is saved.

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: A key-value store and a file system are integrated together to provide improved operations. The key-value store can include a log engine, a hash engine, a sorting engine, and a garbage collection manager. The features of the key-value store can be configured to reduce the number of I/O operations involving the file system, thereby improving read efficiency, reducing write latency, and reducing write amplification issues inherent in the combined key-value store and file system.

Abstract: Provided are an amino acid dehydrogenase mutant and use thereof. The amino acid sequence of the amino acid dehydrogenase mutant has a sequence as shown in SEQ ID NO: 1, and sites at which amino acid mutations occur include a K144G site.

Abstract: The present disclosure relates to a bi-directional overrunning clutch, electronic door locks having bi-directional overrunning clutches, and methods of using the same. In certain embodiments, the electronic door lock includes a first locking mechanism for driving an inner wheel through a first torque to rotate a rotatable shaft to operate a locking device on a door by a user from outside, a second locking mechanism for driving inner wheel through the first torque to operate the locking device from an inside, a third locking mechanism for driving an outer wheel rotatable coaxially around the rotatable shaft through a second torque to operate the locking device electronically, and the bi-directional overrunning clutch. When outer wheel rotates at second torque, inner wheel and rotatable shaft rotate along with outer wheel, and when inner wheel rotates at first torque, outer wheel does not rotate along with inner wheel and rotatable shaft.

Abstract: The present disclosure relates to the field of a stability design of pressure vessels and main bearing members of nuclear engineering, and discloses a new design method for an allowable compressive stress of an axially compressed cylinder. By introducing elastic-plastic influence parameters and cylinder structure characteristic parameters, a critical buckling stress values of axially compressed cylinders under different buckling failure modes and a critical buckling stress reduction factor considering the influence of initial defects are obtained. At the same time, a design safety factor of the axially compressed cylinder is given, and a new calculation flow for the allowable compressive stress of the axially compressed cylinder is put forward. The present method is of great significance to promote the development of large-scale and lightweight axially compressed cylinders in engineering.

Abstract: A UV/O3/H2O2 advanced oxidation reactor includes a water inlet pipe, a water outlet pipe, an ultraviolet reactor, an H2O2 adding device and an O3 adding device. The ultraviolet reactor has a plurality of ultraviolet lamps embedded therein, and the ultraviolet lamps are arranged at an angle with respect to partition plates. The water inlet pipe is connected to a water inlet in a lower portion of the ultraviolet reactor, and the water outlet pipe is connected to a water outlet in an upper portion of the ultraviolet reactor. The H2O2 adding device and the O3 adding device are arranged on a connecting pipe of the water inlet pipe. After raw water is pressurized, H2O2 is added into the raw water through the H2O2 adding device, then ozone is added in the raw water through a water injector, and finally the raw water enters the ultraviolet reactor.