7results about How to "Reduce charge density" patented technology

The invention belongs to the technical field of water treatment, and discloses an oxygen-containing functional group modified cobalt-based carbon nanotube as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing and stirring functionalized carbon nanotubes, cobalt salt, cyanuric acid, melamine and a solvent, and then performing centrifugal separation, washing and drying to obtain a precursor; calcining the precursor in a protective atmosphere, and then pickling to obtain the oxygen-containing functional group modified cobalt-based carbon nanotube. Cobalt nitrate is used as a cobalt source, cobalt exists in the form of ions, in the calcining process, cobalt is embedded into a carbon nano tube by means of nitrogen of melamine, cobalt monoatoms exist, cobalt clusters are generated, oxygen-containing functional groups and the cobalt clusters have a regulation and control effect on a charge structure of an active center of the cobalt monoatoms, and the oxygen-containing functional groups and the cobalt clusters have a regulation and control effect on the active center of the cobalt monoatoms. The electric charge density of a cobalt monatomic active center is weakened together, and the binding energy to an intermediate OOH is regulated and controlled, so that the material is a 2e--ORR electrocatalyst with high activity and high selectivity.

The invention belongs to the technical field of catalytic materials, and particularly relates to a macro-micro-nano integrated structured titanium silicalite molecular sieve catalyst as well as a preparation method and application thereof. According to the catalyst, SiC whiskers are grown on the surface of a 3D communicating hole SiC carrier in situ, TS-1 titanium silicalite molecular sieve precursor coating is combined with a steam crystal transformation process, and a TS-1 titanium silicalite molecular sieve coating with framework nickel doping and open mesopores is grown on the surface of the SiC whiskers, so that the loading capacity and catalytic activity of the titanium silicalite molecular sieve are effectively improved; meanwhile, excellent interface bonding force and a continuous heat conduction channel are provided through the SiC whiskers, and the heat transfer performance is enhanced. Compared with a traditional coating, the coating of the catalyst is rougher, and fluid turbulence and mass transfer efficiency are enhanced. According to the structured titanium silicalite molecular sieve catalyst, the utilization efficiency, the reaction rate and the selectivity of the catalyst are remarkably improved through coupling of macroscopic channels, micron pore channels and nano mesopores, and the structured titanium silicalite molecular sieve catalyst is particularly suitable for phenol hydroxylation reaction and olefin oxidation reaction.

The utility model discloses a silicon carbide MOSFET device comprising at least one cell, and each cell comprises a silicon carbide substrate of a first doping type; an epitaxial layer of a first doping type; the well regions of the second doping type are located in the epitaxial layer, and JFET regions are arranged between the adjacent well regions; the source region of the first doping type is located in the well region; the contact region of the second doping type is located in the well region and is adjacent to the source region; the field oxide layer is located on the surface of the epitaxial layer and located above the JFET region; the gate oxide layer comprises a first gate oxide layer and a second gate oxide layer, and the first gate oxide layer and the second gate oxide layer are located on the two sides of the field oxide layer respectively and are adjacent to the field oxide layer respectively; the gate conductors comprise a first gate conductor and a second gate conductor, the first gate conductor covers the surface of the first gate oxide layer and part of the surface of the field oxide layer, the second gate oxide layer covers the surface of the second gate oxide layer and part of the surface of the field oxide layer, and the first gate conductor and the second gate conductor are separated from each other.

The application provides a positive electrode active material, a preparation method thereof, a positive electrode sheet and a secondary battery. The positive electrode active material comprises a compound with a chemical formula of formula 1: [Na x □ y ]Ni a Fe b Mn c A m Q n O β formula 1, wherein 0.6<=x<1.0, 0.06<=y<=0.4, 0<=a<=0.5, 0<=b<=0.5, 0.35<=c<=0.7, 0<=m<=0.1, 0<=n<=0.1, 1.96<=beta<=2.02, and a<c; □ is a Na vacancy, the Na vacancy comprises an intrinsic Na vacancy and a Na vacancy introduced by the A; the A comprises at least one of metal ions with full or empty d orbitals, and the Q comprises at least one of metal cations with +1 valence or +2 valence. In the application, the A enters the TM layer to replace part of the Mn 4+ , so that the TM n+ is in an electron-deficient state, and spontaneous oxidation reaction is inhibited.

The application discloses a method for preparing 2,5-bis(aminomethyl)furan. The method comprises the following steps: loading 5-hydroxymethylfurfural and ammonia into a reaction kettle loaded with a catalyst, introducing hydrogen into the reaction kettle, and reacting at 150 DEG C to 190 DEG C for 10 to 14 hours to generate 2,5-bis(aminomethyl)furan through a reductive amination reaction; the catalyst is a core-shell structure, and is composed of a silica shell and a metal core; the metal core is metal M, which is Ni or Co; and the molar ratio of the silica to the metal M is 0.1 to 0.3. The application has no by-products, no pollution, less waste, and the conversion rate of 5-hydroxymethylfurfural can reach 99%, the selectivity of 2,5-bis(aminomethyl)furan is 99%, and the green and sustainable production of 2,5-bis(aminomethyl)furan is realized.

The invention relates to a preparation method of a nanofiltration membrane for purifying small molecule peptides, the nanofiltration membrane with pH response comprises a base membrane and a separation surface layer, the base membrane adopts a polymer asymmetric commercial membrane, and the separation surface layer is formed by a material with a pH sensitive group and multi-element acyl chloride through interfacial polymerization reaction. The method has the advantages that the pH response material is added into the water phase monomer, compared with a traditional method, the pH sensitive polymer material is introduced, not only is response to different feeding pH in the filtering process achieved, but also the polymer chain state can be controlled by changing the feeding liquid pH, and therefore the membrane pore diameter is adjusted, and small molecule peptide is accurately separated. In addition, the pH sensitive group carries charges, the charge density on the surface of the membrane is enhanced, the synergistic effect of the charge effect and the screening effect is beneficial to separation of small molecule peptide from inorganic salt and other amino acids, and meanwhile, the biological activity of small molecules is kept. The preparation method is simple, and the obtained nanofiltration membrane with pH response has a wide application prospect.

The utility model relates to the technical field of semiconductors, in particular to a high-voltage metal oxide semiconductor (MOS) diode, which comprises a packaging body, an MOS chip is arranged inside the packaging body, three pins are connected below the packaging body, the three pins are respectively connected with the MOS chip through a first aluminum wire and two second aluminum wires, and the first aluminum wire and the second aluminum wire are respectively connected with the MOS chip. And a source electrode, a grid electrode and a drain electrode are sequentially formed. A plurality of thimbles are arranged on an MOS chip, and a multi-thimble structure is used for carrying out die bonding on the MOS diode, so that the effective width of the MOS chip is increased, the resistance of the MOS diode in a conducting state can be reduced, the conducting characteristic of a device is improved, meanwhile, the multi-thimble structure is adopted, the charge density on the MOS chip can be reduced, the charge voltage drop can be reduced, and the reliability of the device is improved. And the switching speed and the loss characteristic of the device are improved, so that the stress on the MOS chip is dispersed, and the risk of crystal cracking is further reduced.