4results about How to "Eliminate scatter" patented technology

This invention discloses a high-density, high-thermal-conductivity hot-pressed aluminum nitride substrate and its preparation method, belonging to the field of ceramic thermally conductive materials technology. The aluminum nitride substrate is composed of aluminum nitride powder and a composite sintering aid, the composite sintering aid being a fluoride, with a total addition amount of 2%-8% of the aluminum nitride powder mass. The aluminum nitride substrate has a multi-layer composite structure, including an upper dense layer, a middle stress buffer layer, and a lower dense layer. The porosity of the upper and lower dense layers is ≤0.3%, and the porosity of the middle stress buffer layer is 1%-5%. The preparation method includes steps such as raw material mixing, multi-layer molding, hot-pressing sintering, and diamond wire saw cutting. This invention achieves grain boundary purification through a pure fluoride composite aid system, combined with a multi-layer structure design to absorb cutting stress and thermal stress, resulting in a substrate density ≥99.5%, thermal conductivity ≥240W / (mK), and an ultra-thin substrate edge chipping rate ≤3%, while simultaneously reducing the sintering temperature and shortening the production cycle.

The invention provides a three-terminal laminated solar cell based on a silicon nanowire structure, and relates to the technical field of solar cells. A first electrode layer is arranged in the perovskite top cell in the direction facing the incident light, a second electrode layer and a third electrode layer are arranged in the crystalline silicon bottom cell in the direction deviating from the incident light, and a plurality of nanowire structures are arranged on one side, facing the incident light, of an N-type silicon absorption layer at intervals. The nanowire structure can enhance coupling and propagation of long-wave photons to the N-type silicon absorption layer through a waveguide effect and a light field modulation effect, and the nanowire structure presents a sub-wavelength optical characteristic, so that an anti-reflection effect in a wide spectrum range is realized, and the absorption efficiency of the crystal silicon bottom cell on the long-wave photons is improved. In addition, by arranging a three-electrode structure, the overall energy output performance of the battery is improved.

This invention provides a transcranial ultrasound method and system for penetrating the skull. The method includes applying a decalcifying agent to the skull region of a subject to make the skull region acoustically transparent, thereby enabling brain imaging and / or brain therapy; transmitting and receiving sound wave signals to the acoustically transparent head using an ultrasound transducer; acquiring ultrasound images of internal tissues of the head based on the received sound wave signals; and / or transmitting ultrasound waves to the acoustically transparent head using the ultrasound transducer to perform ultrasound therapy. This transcranial ultrasound method fundamentally eliminates the strong reflection, scattering, and energy attenuation of ultrasound waves caused by the skull as an acoustic barrier, significantly improving signal strength. Therefore, this invention not only achieves non-invasive, whole-brain-depth functional ultrasound imaging with resolution up to 20 micrometers, but also greatly improves the accuracy and safety of ultrasound therapy procedures such as targeted drug delivery and neuromodulation.

The application relates to an Au / SnO2 / GND composite gas-sensitive material-based MEMS nitrogen dioxide sensor and a preparation method thereof, and belongs to the technical field of gas sensors. The sensor is composed of a metal tube seat and a MEMS micro-hot plate chip which are coaxially arranged and fixedly packaged, and the Au / SnO2 / GND composite gas-sensitive material is coated on the surface of the chip interdigital electrode. 3 The sp 2 Volume evolution during phase inversion is synchronous with the SnO2 crystallization process, the SnO2 shell and the carbon skeleton are tightly bonded at the atomic scale, lattice strain is induced at the heterojunction interface, and a high concentration of oxygen vacancies is generated; meanwhile, the ultraviolet photochemical reduction method is used to realize the fine and uniform dispersion of gold nanoparticles at a very low noble metal loading (0.5wt%-1.5wt%), and the high concentration of oxygen vacancies generated by the lattice strain constructs a double enhancement mechanism, which significantly improves the catalytic activity of the material and the sensitivity of the sensor.