Abstract: This invention describes a magnetoresistive inertial sensor chip, comprising a substrate, a vibrating diaphragm, a magnetic field sensing magnetoresistor and at least one permanent magnet thin film. The vibrating diaphragm is located on one side surface of the substrate. The magnetic field sensing magnetoresistor and the permanent magnet thin film are set on the surface of the vibrating diaphragm displaced from the base of the substrate. A contact electrode is also arranged on the surface of the vibrating diaphragm away from the base of the substrate. The magnetic field sensing magnetoresistor is connected to the contact electrode through a lead. The substrate comprises a cavity formed through etching and either one or both of the magnetic field sensing magnetoresistors and the permanent magnet thin film are arranged in a vertical projection area of the cavity in the vibrating diaphragm portion.

Abstract: A synergist for a water-base drilling fluid and a preparation method therefor, a water-base drilling fluid and an application thereof, and belongs to the field of drilling fluid technologies. The synergist is prepared from raw materials comprising the following parts by weight: 15˜25 parts of sodium styrene sulfonate, 8˜15 parts of allyl trimethyl ammonium chloride, 2˜8 parts of didodecyldimethylammonium bromide, 1˜5 parts of n-octyl triethoxysilane, 1˜5 parts of propyltriethoxysilane, 1˜5 parts of disodium lauryl sulfosuccinate, 10˜20 parts of nano silica, 8˜15 parts of paraffin, and the like.

Abstract: The present disclosure provides a synergist for a water-base drilling fluid and a preparation method therefor, a water-base drilling fluid and an application thereof, and belongs to the field of drilling fluid technologies. The synergist is prepared from raw materials comprising the following parts by weight: 15˜25 parts of sodium styrene sulfonate, 8˜15 parts of allyl trimethyl ammonium chloride, 2˜8 parts of didodecyldimethylammonium bromide, 1˜5 parts of n-octyl triethoxysilane, 1˜5 parts of propyltriethoxysilane, 1˜5 parts of disodium lauryl sulfosuccinate, 10˜20 parts of nano silica, 8˜15 parts of paraffin, and the like.