Abstract: A method for preventing cracking of nickel-based superalloy fabricated by selective laser melting (SLM) belongs to the field of additive manufacturing (AM). The method of preparing an as-built part with a high density, no crack defects, and good mechanical properties includes: reducing the content of elements Zr and B forming low melting point phase in a nickel-based superalloy, adjusting the total content of Al and Ti in the alloy to 4.5 wt % or below, and combining with the control of special SLM process parameters. The new method has the advantages of a reasonable component design, a simple preparation process, and good performance of the as-built part, and therefore is suitable for large-scale application.

Abstract: A frequency-shift symmetric chirp spread spectrum modulation and demodulation method for interstellar communication links. The transmission process includes several steps: serial-to-parallel conversion, index addition, Gray coding, binary-to-decimal conversion, and frequency-shift symmetric chirp spread spectrum modulation. On the other hand, the reception process comprises demodulation of the symmetric chirp signal, fast Fourier transform, peak retrieval, decimal-to-binary conversion, Gray decoding, index removal, and parallel-to-serial conversion. The frame structure includes a preamble code, synchronization word, and user data. The symmetric chirp signal includes a pair of chirp signals with opposite polarities, ensuring the continuity of phase and frequency during the signal concatenation process.

Abstract: A distributed multi-antenna collaborative phase stabilization device for future broadband wireless communication. The device includes a central station and various antenna terminals interconnected via optical fibers to form a linear communication system. The distributed multi-antenna reception signals are optically modulated at the antenna terminals into different wavelengths of optical signals, and then coupled into a single optical fiber using wavelength division multiplexing technology for transmission to the central station. At the central station, the optical signals are converted back into the original RF (radio frequency) signals through optoelectronic conversion.

Abstract: A device for generating laser with ultra-narrow-linewidth includes an optical self-injection locking loop and an ultra-stable cavity phase-locked loop. The optical self-injection locking loop improves the quality factor of the laser resonator to narrow the linewidth. The ultra-stable cavity phase-locked loop locks the phase of the optical signal in the optical self-injection, synchronizing the laser frequency with the optical resonator. Through feedback control of the laser's driving current, it further reduces the laser's frequency noise and enhances the linewidth narrowing rate. Additionally, the ultra-stable cavity phase-locked loop provides stable control of the laser frequency, preventing mode hopping caused by laser frequency drift, thereby improving system stability. Therefore, this device can provide a stable narrow-linewidth laser source for applications in fiber optic communication, lidar, industrial device processing, and medical fields.

Abstract: A method for preparing a nano spherical oxide dispersion strengthening phase using a micron oxide is proposed for the first time. First, a micron oxide is used as a raw material to prepare a nano oxide with a completely amorphous structure/matrix alloy composite powder by mechanical ball milling in stages. In the first stage, ball milling is performed, causing the oxide to break and transform in structure, and achieving nano-sizing and completely amorphization, to prepare a composite powder with a completely amorphous structure nano oxide uniformly distributed in the matrix alloy powder; and in the second stage, the composite powder obtained in the first stage and the remaining matrix alloy powder are uniformly mixed by ball milling. Then, the uniformly mixed powder is sequentially subjected to hot forming, hot rolling, and heat treatment, to obtain a nano spherical oxide dispersion strengthened alloy.

Abstract: A device for radar target feature recognition based on optical time-delay fast interference scanning. The device includes an antenna unit, an electro-optical converter, an optical time-delay numerical control scanning device, an optical combiner, a photoelectric detector and a power characteristic analysis device. The device quickly scans the delay amount of the two signals through the optical delay line, and calculates the power of the combined signal through photoelectric conversion and linear power detection. By observing the relationship between the combined power and the delay time, the rapid identification of the target radar signal characteristics is realized.

Abstract: A compound represented by formula (I) or a tautomer, an optical isomer, a nitrogen oxide, a solvate, a pharmaceutically acceptable salt or prodrug thereof are useful for treating or relieving an HIF-related and/or EPO-related disease or condition in patient. The preparation method for the compound, and use of a drug composition containing the compound and the compound or the drug composition in preparation of a drug are also provided.

Abstract: A regulator circuit module, a memory storage device, and a voltage control method are disclosed. The voltage control method includes: generating an output voltage according to an input voltage by a driving circuit; generating a feedback voltage according to the output voltage; and controlling the driving circuit by a first regulator circuit to adjust the output voltage in response to a current change caused by the feedback voltage.

Abstract: A medical suspension bridge includes a cross beam, a suspension pipe and a moving module. The cross beam is connected with the suspension pipe. The moving module is movably connected with the cross beam. The cross beam includes a load-bearing beam. The moving module includes a cable carrier moving plate extending to the upper portion of the load-bearing beam. The medical suspension bridge further includes a cable carrier. One end of the cable carrier is connected to the load-bearing beam, and the other end is connected to the cable carrier moving plate. Since cables such as electric wires and air pipes within a box body which needs to be moved are collectively mounted within the cable carrier, not only the routing is more tidy, but also the cables can be well protected.

Abstract: A dual phone case having wireless charging function, including a flexible board, a first case, a second case, and a wireless charging assembly. The flexible board includes a first mounting portion and a second mounting portion, where the first mounting portion is folded with the second mounting portion. The first case is disposed on the first mounting portion, the second case is disposed on the second mounting portion, and the first case and the second case are configured to fix mobile phones. The wireless charging assembly is configured to wirelessly charge the mobile phone, and the wireless charging assembly is disposed on the flexible board. The dual phone case charges the two mobile phones at the same time while protecting the two mobile phones at the same time.

Abstract: A method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles is provided. In the method, a nickel-based superalloy is used as a matrix, and one or more of TiC, TiB2, WC and Al2O3 are used as a strengthening phase. A ceramic particle raw material used as the strengthening phase has a particle size of 1-5 ?m and is added in an amount of 1-5 wt. %. A nickel-based superalloy composite powder having homogeneously distributed nano-scale ceramic is prepared by mechanical milling. A nano-scale ceramic phase strengthened nickel-based superalloy is prepared by 3D printing technology, which has a homogeneously distributed nano-scale ceramic phase and excellent mechanical properties.

Abstract: A high-strength Al-Cu-Mg-Mn aluminum alloy and a preparation method therefor is provided. The alloy includes the following components in percentage by weight: Si:?0.5%, Fe: ?0.5%, Cu: 4.5-6.3%, Mg: 0.6-1.2%, Mn: 0.6-1.5%, Sc: 0.15-0.35%, Zr: 0.1-0.2%, and Y: 0.1-0.3%, the balance being aluminum and non-removable impurities. The preparation method includes: smelting, refining, impurity removing and degassing, pouring, homogenizing heat treatment, three-dimensional large deformation forging pre-deformation, isothermal deformation processing, and heat treatment. A casting mold used is a special combined mold having a metal mold as an inner mold, a surrounding cooling pipe, and a sand mold as an outer mold, and is used to prepare and obtain high-quality, high-performance castings. The heat treatment is solid solution treatment plus gradient aging treatment.

Abstract: The present disclosure relates to the field of additive manufacturing and superalloys, particularly to a method for eliminating cracks in René 104 nickel-based superalloy prepared by laser additive manufacturing. For solving the problem that cracks are easily generated during laser additive manufacturing of René 104 nickel-based superalloy with high content of Al and Ti (Al+Ti>5 wt. %), generation of large-size cracks inside a fabricated part is suppressed by means of designing laser forming parameters and a partition scanning strategy; then stress relief annealing is performed to completely eliminate residual stress inside the fabricated part; and a spark plasma sintering process is performed to eliminate cracks inside the fabricated part and suppress the growth of grains during the sintering process.

Abstract: A thermoplastic elastomer for profile control and water shutoff is prepared from the following raw materials in parts by weight: 8-10 parts of a component A, 1-3 parts of a strong acid, 1-3 parts of a hydrophobic modifier and 100-105 parts of water. The component A is one of polyethylene glycol, polyvinylether, polyvinyl alcohol, copolymer of acrylamide and acrylonitrile. The strong acid is one of concentrated hydrochloric acid and concentrated sulfuric acid. The hydrophobic modifier is any one of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, ?-propiolactone, ?-butyrolactone, ?-valerolactone, methyltriacetylsilane, methyltrimethylsilane, butyl acrylate and ethylene glycol dimethacrylate. The thermoplastic elastomer for profile control and water shutoff provided by the disclosure has the advantages of one-step preparation and molding, strong deformation capability, temperature resistance, salt tolerance, strong stability and the like, and is suitable for large-scale production and application.

Abstract: A downhole rock debris extraction system is provided. The downhole rock debris extraction system includes a downhole marking component, a ground control component and a ground detection and extraction component. The downhole marking component is arranged at a drill bit for underground excavation or near the drill bit, and is configured to mark rock debris by spraying different types of markers in real time during the underground excavation performed by the drill bit; the ground detection and extraction component is configured to detect the types of the markers on the rock debris; and the ground control component is configured to manage and control the downhole marking component to mark the rock debris, and to manage and control the ground detection and extraction component to determine the types of the markers on the rock debris. Furthermore, a control method for the downhole rock debris extraction system is provided.

Abstract: A method of hydrolysis of dimethyl succinyl succinate includes: adding DMSS and water to a reactor, and stirring; adding a phase transfer catalyst to the reactor, and heating; and adding an acid and a transition metal salt to the reactor for hydrolysis of DMSS. The acid is sulfuric acid, hydrochloric acid or nitric acid, and the W ion concentration of the mixture in the reactor is 0.2-12 mol/L. The transition metal salt is a nitrate, sulfate, or chloride of copper, nickel, zinc or manganese, or a combination thereof; and the metal ion concentration of the mixture in the reactor is 0.01-0.1 mol/L.

Abstract: A lignocellulose nanofibril material, a stable foam system based thereon, a preparation method and an application thereof are provided. The lignocellulosic nanofibril material includes the following components: 0.5-20 wt % of wood flour, 0.1-10 wt % of (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl, 2-25 mmol/g of an oxidant, 6-15 wt % of NaBr, and the remaining is water. The stable foam system based on the lignocellulosic nanofibril material includes: 0.1-1.0 wt % of the lignocellulosic nanofibril material, 0.2-1.0 wt % of a surfactant, 0.1-10 wt % of sodium chloride, 0.1-1.0 wt % of calcium chloride, 0.1-1.0 wt % of magnesium chloride, 0.1-1.0 wt % of sodium sulfate, and a balance of water.

Abstract: A method for preparing a nano spherical oxide dispersion strengthening phase using a micron oxide is proposed for the first time. First, a micron oxide is used as a raw material to prepare a nano oxide with a completely amorphous structure/matrix alloy composite powder by mechanical ball milling in stages. In the first stage, ball milling is performed, causing the oxide to break and transform in structure, and achieving nano-sizing and completely amorphization, to prepare a composite powder with a completely amorphous structure nano oxide uniformly distributed in the matrix alloy powder; and in the second stage, the composite powder obtained in the first stage and the remaining matrix alloy powder are uniformly mixed by ball milling. Then, the uniformly mixed powder is sequentially subjected to hot forming, hot rolling, and heat treatment, to obtain a nano spherical oxide dispersion strengthened alloy.