34results about How to "Improve anti-separation performance" patented technology

The invention relates to a vortex generator structure for suppressing boundary layer separation under the action of shock waves. One or more vortex generator structures arranged in parallel are arranged, so that a flow control device is obtained. The flow control device aims at improving separation-resistant capacity of boundary layers in ultrasonic gas flowing under the action of the shock waves. A vortex generator is of a tetrahedral structure basically and is located in an interference region upstream boundary layer where shock wave boundary layers interact, the distance between a vortex generator trailing edge and an interference region initial point is 15-30 times of a boundary layer thickness when no control exists in the position where the vortex generator is located, the height of the vortex generator trailing edge is 0.3-0.8 time of a boundary layer thickness when no control exists in the position where the vortex generator is located, the length is directly proportional to the trailing edge height of the vortex generator, the specific value of the length to the trailing edge height is 5 to 10, the width is directly proportional to the trailing edge height of the vortex generator, the specific value of the width to the trailing edge height is 2 to 4, the distance between vortex generators is directly proportional to the trailing edge height of the vortex generator, and the specific value of the distance to the railing edge height is 6 to 10. The vortex generator structure is suitable for supersonic flow fields where the shock waves induce separation of boundary layers.

The invention discloses a polypropylene composite material that has excellent light and aging resistant performance and a preparation method thereof. The polypropylene composite material that has excellent light and aging resistant performance consists of raw materials comprising 55 to 95wt percent of polypropylene, 0 to 40wt percent of inorganic filler, 0 to 20wt percent of toughener POE, 0.1 to 5wt percent of molecular sieve activator powder, 0.1 to 1wt percent of main chemical inhibitor, 0.1 to 1wt percent of secondary chemical inhibitor, 0.1 to 2wt percent of light stabilizer agent and 0 to 5.0wt percent of other additives. By adding powder molecular sieve into basic formulation of the polypropylene composite material, the dispersibility of the light stabilizer agent in the polypropylene composite material is effectively improved, thus improving the light and aging resistant performance of the polypropylene composite material.

The invention provides liquid metal carboxylate. The liquid metal carboxylate is prepared with the following method: mixed acid is mixed with a metal precursor, an organic solvent and a phase transfer catalyst, and the mixture is reacted at the temperature of 80-130 DEG C for 2-4 h; a reaction liquid is subjected to decompression dehydration and is filtered, and a filtrate is collected, and the liquid metal carboxylate is obtained. An acyclic polyether transfer catalyst is introduced into the preparation process of the liquid metal carboxylate, the reaction efficiency of fatty acid salt can be effectively improved, the acid value of the reaction end point is reduced, and the reaction yield is improved; the liquid metal carboxylate can be applied to preparation of a composite PVC (polyvinyl chloride) heat stabilizer, and the thermal stability and the precipitation resistant performance of the composite PVC heat stabilizer system can be improved.

The invention discloses a polyvinyl chloride sealing strip composition and a preparation method thereof, and belongs to the technical field of processing and application of polymer materials. The polyvinyl chloride sealing strip composition comprises, by weight, 100 parts of PVC resin, 95-97 parts of a plasticizer, 4-5 parts of a calcium-zinc stabilizer, 0.2-0.3 part of an antioxidant, 18-20 partsof a filler and 0.3-0.5 part of a lubricant; and the plasticizer is a polyester plasticizer and carbon dioxide-based polymer compound. The polyvinyl chloride sealing strip composition has high anti-precipitation performance, the adhesion stress of a PCM plate is 9.5-10.5 N, and the preparation method can meet 80 m/min high-speed extrusion production, and improves the production efficiency.

At least one of a center electrode and a ground electrode of a spark plug includes an electrode body, an electrode tip, and a welded portion formed between the electrode body and the electrode tip. The electrode tip includes a cover layer that covers at least a side surface of a tip body, and the cover layer is formed of IrAl. On a section formed by cutting the electrode tip near a boundary with the welded portion, an area of the tip body is represented by Sa. An area of a projection on the section of a non-contact portion of an opposite surface of the tip body not in contact with the welded portion is represented by Sb. In this case, Sa−Sb corresponds to 35% or more of Sa.

A door and window sealing strip composition comprises the following parts by weight of raw materials: 60 to 80 parts of chlorinated polyethylene; 20 to 40 parts of polyvinyl chloride; 10 to 20 parts of a plasticizer; 2 to 3 parts of magnesium oxide; 3-6 parts of a calcium and zinc compound stabilizer; 0.5-1 part of stearic acid; 0.5-1 part of paraffin; 0.5-1.5 part of a peroxide crosslinker; 0.5-1part of a titanate coupling agent; 30 to 40 parts of calcium carbonate and 2 to 3 parts of carbon black. The door and window sealing strip composition has high anti-precipitation performance, can meet high-speed extrusion production of 80 m/min, improves production efficiency, has high tensile strength and low temperature embrittlement resistance, and is suitable for use in low temperature areas.

The invention relates to an embedded shearing resistant connector for steel web prestress concrete slab-composite slab, which comprises a plurality of rectangular steel sheets and steel webs (the shapes of the steel webs are various), wherein the rectangular steel sheets are welded onto the upper sides and the lower sides of the steel webs and are vertical to the steel webs; the rectangular steel sheets are welded to the steel webs (the welding properly adopts laser welding or arc welding, and carbon dioxide shield welding on the premise of ensuring the quality). According to the invention, the shearing resistant connector effectively plays the role of shearing prevention, the grappling length of the steel webs is effectively increased, the cohesion of concrete of the steel webs is increased, and the separation resistance of the concrete and the steel webs is improved. The connector is convenient to process, quick in welding, automatic in production and very practical for the type of stacking boards, has higher popularization value, is provided with good performance of fatigue resistance, and can resist the action of pull and push.

The invention provides an attachment part designed to be mounted in an opening (12) in a wall (10) of a vehicle seat frame, said attachment part comprising: a body (31) designed to receive a locking element (40) and holding means (34, 35a) to hold the body (31) on the wall (10), the holding means (34, 35a) comprising at least one articulated portion (34), characterised in that said at least one articulated portion (34) is arranged such that, when the attachment part is mounted in the opening (12) in the wall (10) and the locking element (40) is received in the body (31), the at least one articulated portion (34) is locked in place by said locking element (40) in a position in which it bears against said wall (10).

The invention provides preparation and application of high-purity lavender oil, the high-purity lavender oil is prepared by selecting a distillation method to assist a filter membrane, and the pretreated filter membrane is subjected to soaking and plasma activating treatment, so that the filtering interception capacity of the filter membrane is greatly improved, impurities in the lavender oil are filtered out, and the purity of the lavender oil is improved. The purity of the lavender oil is further improved; a specific clarifying agent is matched with lavender oil, the problem that the clarity of the lavender oil is reduced after the lavender oil is stored for a period of time is solved, a compound stabilizer is specifically added, an auxiliary agent is blended with fatty acid polyoxyethylene ether, soybean phospholipid, tween-20 and epoxidized soybean oil which have a stabilizing effect, and then the mixture is added into the lavender oil, so that the lavender oil is obtained. The negative influence of the lavender oil stabilizing system caused by the use of the clarifying agent is solved, the precipitation resistance of the lavender oil is improved, and the storage stability of the lavender oil is greatly improved; the prepared high-purity lavender oil can be used for skin care.