Abstract: An optical grating comprising a refractive index with a periodic pattern that includes a base period ?0; a periodic sampling of the base period, with a first period ?1 and a first duty cycle p1, thereby defining a single-sampled grating (SSG); and a periodic sampling of the SSG, with a second period ?2 and a second duty cycle p2. The resulting dual-sampled grating (DSG) can have a reflection spectrum containing reflection peaks. If two DSGs having different reflection spectra share a common interface, a tunable optical filter can be produced, where electrical or heating means can cause a reflection peak of one spectrum to be shifted to coincide with a reflection peak of the other spectrum, thereby filtering the corresponding wavelength. By inserting between the two DSGs a gain medium and a phase-tuning medium, a laser source structure is realized. Either device can be produced by etching or stacking methods.

Abstract: Embodiments of the present application relate to the technical field of communication transmission security, and in particular, to a method and a device for mining a security vulnerability of an air interface protocol, and a mobile terminal. The method for mining the security vulnerability of the air interface protocol includes: obtaining mutation data, the mutation data being generated according to a fuzzing task; obtaining a service message of the air interface protocol; modifying the service message according to the mutation data; sending the modified service message to a base station; and monitoring a state of the base station, and recording a security vulnerability log according to the state of the base station.

Abstract: A three-phase power supply conversion circuit includes rectifier, energy storage, direct-current load, and control modules. The rectifier module includes a three-phase rectifier bridge including three bridge arms connected in parallel to each other, and a bidirectional switch assembly including three bidirectional switches. One ends of the three bidirectional switches are connected to midpoints of the three bridge arms, respectively. The energy storage module is connected to a direct-current output end of the rectifier module and includes first and second capacitors connected in series to each other. Other ends of the three bidirectional switches are connected between the first and second capacitors. The control module is connected to the bidirectional switch assembly and configured to control the bidirectional switches according to phase voltages of a three-phase alternating-current power supply, to maintain a voltage between two ends of the first or second capacitor at a target voltage.

Abstract: The present disclosure provides genetic constructs comprising a recombinant internal ribosome entry site (IRES), which may be used as riboswitches to modulate translation of an operably-mRNA sequence encoding a protein of interest in a plant. In other aspects, the disclosure provides recombinant plant cells, methods, kits and systems that utilize the same, e.g., to provide a platform for modulating the expression of essentially any protein of interest in a plant cell.

Abstract: A pyram-shaped deep-sea pressure-resistance shell and a design method therefor. The shell comprises a conical shell, an annular combined shell, a cylindrical shell, a flange bolt, and a perforated thick plate; a bottom end of the conical shell is connected with a top end of the annular combined shell, the conical shell being in communication with an interior part of the annular combined shell; the perforated thick plate blocks the bottom end of the annular combined shell, the perforated thick plate and the annular combined shell being connected by means of multiple flange bolts; the cylindrical shell is disposed inside the annular combined shell, a lower end of the cylindrical shell being inserted in a gap between the annular combined shell and the perforated thick plate.

Abstract: A pyram-shaped deep-sea pressure-resistance shell and a design method therefor. The shell comprises a conical shell, an annular combined shell, a cylindrical shell, a flange bolt, and a perforated thick plate; a bottom end of the conical shell is connected with a top end of the annular combined shell, the conical shell being in communication with an interior part of the annular combined shell; the perforated thick plate blocks the bottom end of the annular combined shell, the perforated thick plate and the annular combined shell being connected by means of multiple flange bolts; the cylindrical shell is disposed inside the annular combined shell, a lower end of the cylindrical shell being inserted in a gap between the annular combined shell and the perforated thick plate.

Abstract: The present invention relates to a method for preparing a sulfur-resistant catalyst for aromatics saturated hydrogenation, comprising the steps of: preparing noble metal impregnation solutions from a noble metal and deionized water or an acid solution; impregnating a carrier with the impregnation solutions sequentially from high to low concentrations by incipient impregnation; homogenizing, drying, and calcinating to obtain the sulfur-resistant catalyst for aromatics saturated hydrogenation. The catalyst for aromatics saturated hydrogenation prepared by the method according to the present invention is primarily used in processing low-sulfur and high-aromatics light distillate, middle distillate, atmospheric gas oil, and vacuum gas oil.

Abstract: Disclosed are a method for preparing a noble metal hydrogenation catalyst comprising preparing a carrier from a molecular sieve having a 10-member ring structure and/or an amorphous porous material; preparing a noble metal impregnation solution; and preparing noble metal impregnation solutions in a concentration gradient ranging from 0.05 to 5.0 wt % with deionized water, and sequentially impregnating the carrier with the impregnation solutions from low to high concentrations during the carrier impregnation process, or preparing a noble metal impregnation solution at a low concentration ranging from 0.05 to 0.5 wt % and impregnating the carrier by gradually increasing the concentration of the noble metal impregnation solution to 2.0 to 5.0 wt % in the impregnation process, followed by homogenization, drying, and calcination, as well as a noble metal hydrogenation catalyst, use thereof, and a method for preparing lubricant base oil.

Abstract: Disclosed are a method for preparing a noble metal hydrogenation catalyst comprising preparing a carrier from a molecular sieve having a 10-member ring structure and/or an amorphous porous material; preparing a noble metal impregnation solution from one or more of compounds of noble metals Pt, Pd, Ru, Rh, Re, and Ir and deionized water or an acid solution; and preparing noble metal impregnation solutions in a concentration gradient ranging from 0.05 to 5.0 wt % with deionized water, and sequentially impregnating the carrier with the impregnation solutions from low to high concentrations during the carrier impregnation process, or preparing a noble metal impregnation solution at a low concentration ranging from 0.05 to 0.5 wt % and impregnating the carrier by gradually increasing the concentration of the noble metal impregnation solution to 2.0 to 5.

Abstract: The present invention relates to a method for preparing a sulfur-resistant catalyst for aromatics saturated hydrogenation, comprising the steps of: preparing noble metal impregnation solutions from a noble metal and deionized water or an acid solution; impregnating a carrier with the impregnation solutions sequentially from high to low concentrations by incipient impregnation; homogenizing, drying, and calcinating to obtain the sulfur-resistant catalyst for aromatics saturated hydrogenation. The catalyst for aromatics saturated hydrogenation prepared by the method according to the present invention is primarily used in processing low-sulfur and high-aromatics light distillate, middle distillate, atmospheric gas oil, and vacuum gas oil.