Abstract: This invention relates to the technical field of harmonic elimination for ferromagnetic resonance for a voltage transformer (abbreviated as PT), in particular, to a harmonic elimination method for ferromagnetic resonance for an active resistance-matching voltage transformer based on PID-adjustment, including compiling a resistance matching algorithm; designing and building a harmonic elimination control system based on the PID control strategy; presetting an active resistance-matching strategy; designing an engineering scheme for placing resistors.

Abstract: This invention relates to the technical field of harmonic elimination for ferromagnetic resonance for a voltage transformer (abbreviated as PT), in particular, to a harmonic elimination method for ferromagnetic resonance for an active resistance-matching voltage transformer based on PID-adjustment, including compiling a resistance matching algorithm; designing and building a harmonic elimination control system based on the PID control strategy; presetting an active resistance-matching strategy; designing an engineering scheme for placing resistors.

Abstract: A method for making a solventless polyorganosiloxane pellet is disclosed. The pellet is comprised of a polyorganosilicate resin and a polyorganosiloxane gum. The pellet is useful for making silicone pressure sensitive adhesive compositions.

Abstract: The present disclosure relates to the technical field of coal mining, and in particular, to a mining method without coal pillars with roof-cutting and roadway retaining, comprising: constructing a gas drainage roadway and eliminating outbursts in a working face transport gate area and a working face track gate area on opposite sides of a first mining working face; constructing the working face track gate, the working face transport gate, a first process roadway and a second process roadway, one end of the working face track gate is communicated with an air return roadway, the other end is communicated with the gas drainage roadway by the first process roadway, one end of the working face track gate is communicated with the air return roadway, the other end is communicated with the gas drainage roadway by the second process roadway; stoping the working face, forming an roadway retaining section, the roadway retaining section is communicated with the gas drainage roadway by the first process roadway and the sec

Abstract: The present disclosure relates to the technical field of mine ventilation, and in particular, to a three-dimensional ventilation method and system for mining by 110 construction method in coal and gas outburst mines.

Abstract: A sand control screen for heavy oil thermal recovery, including: a core base pipe having a plurality of base-pipe holes distributed on a pipe body thereof; a filtering sleeve sleeved on the core base pipe and arranged with respect to the base pipe holes; and a non-welded support disk mounted on the core base pipe and fastening the filter sleeve to the core base pipe by means of a wedge insertion locking and sealing structure. The invention solves the problems in the prior art in which sand control screen has a poor reliability in a high-temperature condition of a thermal production well, resulting in potential safety risks of down hole sand control operation of the screens. In addition, the sand control screen of the present invention has a long service life, thus improving cost effectiveness of oil wells.

Abstract: An oil well cement settlement stabilizer is ternary cement settlement stabilizer or quaternary cement settlement stabilizer; wherein the quaternary cement settlement stabilizer containing structural units A represented by formula (I), structural units B represented by formula (II), structural units C represented by formula (III), and structural units D represented by formula (IV); Wherein the ternary cement settlement stabilizer containing structural units A represented by formula (I), structural units B represented by formula (II), and structural units D represented by formula (IV);

Abstract: An oil well cement settlement stabilizer is ternary cement settlement stabilizer or quaternary cement settlement stabilizer; wherein the quaternary cement settlement stabilizer containing structural units A represented by formula (I), structural units B represented by formula (II), structural units C represented by formula (III), and structural units D represented by formula (IV); Wherein the ternary cement settlement stabilizer containing structural units A represented by formula (I), structural units B represented by formula (II), and structural units D represented by formula (IV);

Abstract: Disclosed are a composite water-controlling and flow-limiting device and a screen pipe thereof. The composite water-controlling and flow-limiting device comprises a composite water-controlling screen pipe. The composite water-controlling screen pipe comprises: a base pipe (1); a self-adaptive internal flow control device (3) mounted on the base pipe and used for a circulation channel for fluids inside and outside the base pipe and controlling an opening degree of the circulation channel according to the change in viscosity of different fluids so as to automatically limit flow; a flow control device (4) mounted on the base pipe and adjacent to the self-adaptive internal flow control device for controlling an overflow of the base pipe; and a screen pipe coaxially and threadedly connected to the base pipe, wherein an inner diameter of the screen pipe is the same as that of the base pipe.

Abstract: A sand control screen for heavy oil thermal recovery, including: a core base pipe having a plurality of base-pipe holes distributed on a pipe body thereof; a filtering sleeve sleeved on the core base pipe and arranged with respect to the base pipe holes; and a non-welded support disk mounted on the core base pipe and fastening the filter sleeve to the core base pipe by means of a wedge insertion locking and sealing structure. The invention solves the problems in the prior art in which sand control screen has a poor reliability in a high-temperature condition of a thermal production well, resulting in potential safety risks of down hole sand control operation of the screens. In addition, the sand control screen of the present invention has a long service life, thus improving cost effectiveness of oil wells.

Abstract: Disclosed are a gradient bioceramic coating comprising a rare earth oxide, a broadband laser method for preparing the bioceramic coating, and the use of the bioceramic coating in the field of medical materials.

Abstract: Disclosed are a gradient bioceramic coating comprising a rare earth oxide, a broadband laser method for preparing the bioceramic coating, and the use of the bioceramic coating in the field of medical materials.

Abstract: Disclosed are a gradient bioceramic coating comprising a rare earth oxide, a broadband laser method for preparing the bioceramic coating, and the use of the bioceramic coating in the field of medical materials.

Abstract: Disclosed are a gradient bioceramic coating comprising a rare earth oxide, a broadband laser method for preparing the bioceramic coating, and the use of the bioceramic coating in the field of medical materials.