39results about How to "The process preparation method is simple" patented technology

The invention provides a preparation method for a silicon nanowire. The preparation method comprises the following steps of: providing a silicon-on-insulator (SOI) substrate, wherein the SOI substrate comprises a bottom silicon substrate, a buried oxide layer positioned on the bottom silicon substrate and a top silicon film positioned on the buried oxide layer; forming a silicon nitride layer on the top silicon film; photoetching and defining an active area by utilizing a first mask plate, and removing the silicon nitride layer outside the active area in an etching way; removing the top silicon film outside the active area in the etching way by taking the silicon nitride layer of the active area as a mask, and simultaneously making the sidewall of the top silicon film of the active area form a slope shape; performing an oxidization process on the top silicon film of the active area to form a sidewall oxide layer on the sidewall of the top silicon film of the active area; removing the silicon nitride layer of the active area in the etching way; photoetching and defining a silicon nanowire supporting area by utilizing a second mask plate, and etching the top silicon film of the active area under the protection of the sidewall oxide layer to form the silicon nanowire with a triangular section; and removing the sidewall oxide layer and part of the buried oxide layer in the etching way to suspend the silicon nanowire in midair. The preparation method is simple, controllable and low in production cost.

The invention discloses a preparation method of a soft magnetic composite material with high saturation magnetic flux density and high magnetic permeability. A new type of soft magnetic composite material is prepared by coating the surface of soft magnetic alloy powder with an insulating coating layer formed of iron oxide by surface oxidation process, followed by bonding, pressing and heat treatment. The advantages of the present invention are: the preparation of soft magnetic composite materials by surface oxidation process is simple, and the thickness of the insulating layer is easy to control, and because the reaction is an in-situ reaction, the generated oxide insulating layer and the soft magnetic alloy have a relatively Strong binding force, not easy to fall off in the subsequent pressing process. The invention does not add chemical components that pollute the environment, does not pollute the environment, has high effective magnetic permeability and low loss, and because the composition of the insulating coating layer is a ferromagnetic oxide, it can effectively reduce the magnetic flux. Dilution phenomenon, so that the obtained soft magnetic composite material has a higher saturation magnetic induction.

The invention relates to a MOF@POP-n composite catalyst, a preparation method and application thereof, and belongs to the technical field of chemical catalytic materials. The preparation method includes the following steps: dissolving benzyl dibromide in toluene to obtain solution A, dissolving 1-vinylimidazole in toluene to obtain solution B, uniformly mixing solution A and solution B, at 100-120° C., under N2 atmosphere Under heating for 12-24h, after cooling, filtering, washing to obtain the precursor; adding the precursor, divinylbenzene and MOF to the N,N-dimethylformamide solution containing azobisisobutyronitrile, ultrasonicating for 15 ‑45min, heated under nitrogen atmosphere at 120‑160℃ for 24‑48h, cooled to room temperature and separated to obtain the target product. The MOF@POP-n composite catalyst catalyzes propylene oxide and carbon dioxide to generate cyclic carbonate with a yield of up to 98%, and the conversion rate can still reach more than 90% after 6 times of reuse.

The invention discloses a method for preparing a compound surfactant / La-Ni-Mo-W codeposited coating on a copper matrix. The method comprises the following steps: pretreating a pure copper sheet by polishing, deoiling and etching; and carrying out electroplating under thermostatic water bath conditions by using the copper sheet as a cathode and a platinum-plated metal titanium screen as an anode, thereby obtaining the compound surfactant / La-Ni-Mo-W codeposited coating. The compound surfactant and rare-earth element lanthanum (La) are added into the nickel (Ni)-molybdenum (Mo)-tungsten (W) plating solution to prepare the codeposited coating; and the obtained compound surfactant / La-Ni-Mo-W codeposited coating has the advantages of uniform thickness, high hardness, favorable wear resistance, favorable corrosion resistance, high stability and high hydrogen evolution activity.