44 results about "Helium atom" patented technology

A method for improving the quality of a SiC layer by effectively reducing or eliminating the carrier trapping centers by high temperature annealing and a SiC semiconductor device fabricated by the method. The method for improving the quality of a SiC layer by eliminating or reducing some carrier trapping centers includes the steps of: (a) carrying out ion implantation of carbon atom interstitials (C), silicon atoms, hydrogen atoms, or helium atoms into a shallow surface layer (A) of the starting SiC crystal layer (E) to introduce excess carbon interstitials into the implanted surface layer, and (b) heating the layer for making the carbon interstitials (C) to diffuse out from the implanted surface layer (A) into a bulk layer (E) and for making the electrically active point defects in the bulk layer inactive. After the above steps, the surface layer (A) can be etched or mechanically removed. The SiC semiconductor device is fabricated by the method.

The invention discloses a polycarboxylate superplasticizer composition which is prepared from a polycarboxylate superplasticizer and an adsorption shielding agent. The adsorption shielding agent has the chemical structural formula shown as (1), wherein the value of a ranges from 0 to 100; the value of b ranges from 200 to 3000; the value of c ranges from 2 to 10; R1 represents methyl or hydrogen atoms; R2 represents methyl, hydrogen atoms, helium atoms or bromine atoms; R3 represents methyl, hydrogen atoms, helium atoms, bromine atoms or hydroxy; R4 represents methyl or hydrogen atoms. The polycarboxylate superplasticizer composition has the good clay-resisting performance, and can be used for decreasing the sensibility of concrete or mortar to gravel raw materials with high mud content.

The invention discloses phenoxylmethyl siloxane shown as the formula (I) and a preparation method of phenoxylmethyl siloxane. The preparation method of the compound comprises the following steps of: taking raw materials according to the mole ratio of helium atoms in high-boiling-point chlorosilane waste liquid to phenol being 1: (1-1.5); adding phenol into a reactor, and dropwise adding the high-boiling-point chlorosilane waste liquid into the reactor at the temperature of 40 DEG C; after the dropwise adding operation is ended, heating to 60-100 DEG C, and reacting for 8-13h until no HCl is discharged; and carrying out reduced pressure distillation on the reacted materials, removing byproducts distilled at the temperature lower than 170 DEG C and incompletely-reacted phenol, and then, collecting a fraction, i.e., phenoxylmethyl siloxane as a product distilled at the temperature of 230-260 DEG C. The high-boiling-point chlorosilane waste liquid as an industrial waste is used as the raw material, and obtained phenoxylmethyl siloxane has good thermal stability, oxidation resistance and a high flash point and is suitable for hydraulic oil, diffusion pump oil and conduction oil. The formula of phenoxylmethyl siloxane is shown as (RO)nSi-Si(CH3)6-n (I).