8results about How to "Improve electrical resistance" patented technology

The invention discloses a modified polypropylene-based insulating material and a preparation method thereof, and belongs to the technical field of high polymer materials, the modified polypropylene-based insulating material comprises the following raw materials by weight: 90-110 parts of antioxidant polypropylene, 4-6 parts of a heat stabilizer, 18-24 parts of a modified insulating stabilizer, and 1-3 parts of a beta nucleating agent; the antioxidant polypropylene is an antioxidant 3052 grafted polypropylene; the anti-oxidation polypropylene with good heat aging resistance is introduced, the insulation aging phenomenon of an insulation layer is effectively improved, the direct current dielectric property of the polypropylene-based insulation material is improved, in addition, the modified insulation stabilizer with good compatibility is introduced, meanwhile, the polypropylene-based material is endowed with good strength and insulativity, and the service life of the polypropylene-based insulation material is prolonged. The breakdown phenomenon of the insulating layer is effectively avoided, and the service life of the polypropylene-based insulating material is prolonged through the synergistic effect of the polypropylene-based insulating material and the insulating layer.

The invention discloses a filter and a radio frequency front-end module. The filter comprises an input terminal, an output terminal, a grounding terminal and at least two-order resonance units. The resonance unit comprises a series arm resonance group and a parallel arm resonance group. At least one of the series arm resonance group and the parallel arm resonance group comprises at least two resonators which are connected in series, and a common bus bar is arranged between any two adjacent resonators in the at least two resonators which are connected in series. The at least two-order resonance unit comprises a first-order resonance unit and a second-order resonance unit, and the first-order resonance unit is closer to the input terminal than the second-order resonance unit. Wherein the thickness of the common bus bar of the first-order resonance unit is larger than that of the common bus bar of the second-order resonance unit, and / or the width of the common bus bar of the first-order resonance unit is larger than that of the common bus bar of the second-order resonance unit. The power density borne by the common bus bar of each order of resonance unit is balanced, and the breakdown risk is effectively reduced.

The invention relates to the field of polyethylene insulation materials, and particularly discloses a polyethylene insulation material for an ultrahigh-voltage cable and a preparation method of the polyethylene insulation material, and the polyethylene insulation material comprises the following raw materials in parts by weight: 60-100 parts of polyethylene resin, 0.4-1.2 parts of an antioxidant, 1.5-5.5 parts of a cross-linking agent, 5-15 parts of a stabilizer and 3.5-15 parts of a composite modifier. Wherein the composite modifier is a mixture of nano magnesium oxide and laurinol. The polyethylene insulating material provided by the invention has excellent electrical properties, excellent mechanical properties and stable performance, and meets the requirements of insulating materials for ultrahigh-voltage cables.

The application discloses a kind of high surface natural micropore structure regulation-based high surface withstand voltage polyimide and preparation method and application thereof, belong to high voltage insulating material technical field, after drying diamine is dissolved in solvent A, then add dianhydride, after stirring uniformly, obtain polyamide acid solution;Add pore forming agent again, high-speed stirring is uniformly dispersed, obtain mixed viscous solution C;After coating, drying, imidization high temperature heating, and natural cooling, immerse in liquid B and extract pore forming agent, after drying, obtain high surface natural micropore structure regulation-based high surface withstand voltage polyimide.The polyimide surface has natural pore structure, surface is along the surface of electric field, and the through-hole structure is densely distributed along the surface of electric field, and the electron is easy to drop into the through-hole structure in the jumping multiplication process when flashover, and it is difficult to return to the surface, so that the secondary electron multiplication process is inhibited, the probability of forming secondary electron avalanche is reduced, so as to realize the improvement of surface withstand voltage.

The invention relates to the technical field of electronic control devices, in particular to a contact part and a relay. The contact part is provided with at least two parallel branches which are arranged in the same current path in parallel, each parallel branch is provided with a contact group, and each contact group comprises a movable contact and a static contact; at least two of the parallel branches form an alternating group; in the alternating groups, the movable contact and / or the static contact of each contact group comprises at least two electric contact layers, and each electric contact layer is arranged along the height direction of the corresponding movable contact or static contact.

The invention relates to an ethylene propylene rubber insulated mining energy storage cable and a preparation method thereof, and relates to the technical field of wire and cable manufacturing, the cable comprises a cable core, a wrapping tape and a sheath, the cable core is formed by twisting a direct current cable core, a control cable core and a temperature sensing optical cable; the direct-current insulating layer is prepared from ethylene propylene rubber, modified calcined clay, nano magnesium hydroxide, superfine aluminum hydroxide, an assistant crosslinker and other raw materials, and the water tree resistance is improved through the synergistic effect of lamellar filler and a cross-linked network; the temperature sensing optical cable is filled with thixotropic buffer paste containing molybdenum disulfide, dynamic reverse pre-twisting is applied during cabling, the pay-off tension is controlled to be smaller than 75% of a direct-current cable core, and physical excess length is given to the optical fiber structure; and the sheath is made of a low-smoke halogen-free flame-retardant material formed by blending EVA and POE. The problems of insulation aging and optical fiber breakage of the mining cable in a humid vibration environment are solved, and the electrical insulating property, the mechanical flexibility and the state monitoring reliability of the cable are improved.

The invention relates to the technical field of floor pouring, and provides a high-voltage direct-current insulation floor pouring device for rail transit and a pouring process thereof.The high-voltage direct-current insulation floor pouring device comprises a bottom plate, a stuffing box used for containing micron-sized silica powder is fixedly installed on the bottom plate, and a stirring barrel is fixedly connected to the bottom plate; the stirring barrel is communicated with a feeding box for containing a special thixotropic agent through a feeding pipe, a mixing mechanism is arranged on the stirring barrel, a pouring mechanism is arranged on the stirring barrel, a temperature and humidity control mechanism is arranged on the bottom plate, the mixing mechanism comprises a feeding assembly, a feeding assembly and a stirring assembly, and the feeding assembly is arranged on a stuffing box. The conveying assembly is arranged on the feeding pipe and used for conveying the micron-sized silica powder into the stirring barrel, the feeding assembly is arranged on the feeding pipe and used for conveying the special thixotropic agent into the stirring barrel, and the stirring assembly is arranged in the stirring barrel and used for stirring the micron-sized silica powder and the special thixotropic agent. And the pouring efficiency is improved.

The utility model relates to the technical field of new energy copper bar conductor production, in particular to a copper bar extrusion molding and rubber coating constant-temperature shaping device, which comprises an extrusion molding mechanism, a code spraying mechanism and a constant-temperature shaping mechanism, the constant-temperature shaping mechanism comprises a constant-temperature bracket, a constant-temperature water tank arranged on the constant-temperature bracket, and a first constant-temperature area, a second constant-temperature area and a third constant-temperature area which are arranged on the constant-temperature water tank; the first constant-temperature area, the second constant-temperature area and the third constant-temperature area are sequentially lowered; a first water circulation system, a second water circulation system and a third water circulation system are arranged on the constant-temperature support, the first water circulation system is used for water circulation of the first constant-temperature area, the second water circulation system is used for water circulation of the second constant-temperature area, and the second water circulation system is used for water circulation of the second constant-temperature area. According to the utility model, the three groups of constant temperature areas and the corresponding water circulation systems are adopted, the water circulation systems control the water temperature to a certain temperature and then flow to shape and cool the insulating layer of the copper bar, and the shaping effect is good.