Abstract: The present invention provides a ring varistor for use in DC micromotor including a ring varistor substrate having nonlinear volt-ampere characteristics and at least three independent electrodes evenly sintered on an end face of the ring varistor substrate. The electrode gap between two adjacent electrodes consists of two straight parallel edges of the two adjacent electrodes, and an inner and an outer concentric arc on the substrate ring, the electrode gap is not orthogonal to the ring. Due to the asymmetry arrangement of the surface electrodes and the electrode gaps, the electrode materials and the substrate materials with different thermal conductivity have no contact cross distribution with each other at the radial electrode gap. During welding, the heat shock is transmitted asymmetrically through the asymmetric electrodes, to improve the uniformity of the heat conduction distribution of the varistor and reduce the defective rate of the substrate welding fracture.

Abstract: The present invention provides a bottom ohmic silver paste for strontium titanate ring varistor including silver powder, doped SnO2 micro powder, glass powder, organic solvent and organic binder, and the mass ratio of the silver powder, the doped SnO2 micro powder, the glass powder, the organic solvent and the organic binder is [65,85]:[0.9,4.3]:[0.5,5]:[10,20]:[10,15]. The present invention also provides a preparation method and use of the bottom ohmic silver paste for strontium titanate ring varistor of the present invention.

Abstract: A magnetic paper product capable of being printed directly and the preparation method thereof are provided. The product has the unique feature, consisting of a friction-holding covering thin layer, on which sequentially set with a magnetic layer and a printable layer. The friction-holding covering thin layer is a nonwoven fabric called cotton paper (mianzhi) in Chinese. It can achieve the effect of printing magnetic paper after being magnetized, eliminating the trouble that the terminal user has to magnetize the paper after printing, improving the grade of inflexibility of the magnetic paper, reflection of the light and the flatness of the printing surface, solving the problem which has been a plague of the magnetic paper industry and the printing industry for long time.

Abstract: The invention relates to modified electrodes for ER fluids prepared by adding a rough, wear-resisting, and low conductive modified layer on the surface of metallic electrodes. The material for the modified layer can be at least one from diamond, alumina, titanium dioxide, carborundum, titanium nitride, nylon, polytetrafluoroethylene, adhesive, and adhesive film. Through the addition of the modified layer, the adhesion of the ER fluid to electrodes is increased so that the shear stress measured near the plates is close to the intrinsic value, which makes the ER fluid applicable, while reducing the leakage current and increasing the breakdown voltage of the ER fluid equipment.

Abstract: Polar molecules dominated electrorheological fluids mainly comprising a mixture of dispersed phase of solid particles and/or dispersing liquid medium. The dispersed phase solid particles, on the surface, or the liquid dispersing medium contain polar molecules or polar groups, the dipole moment of which is 0.5-10 deb and the size is between 0.1 nm and 0.8 nm. Dispersed phase solid particles are spherical or nearly spherical, of which the size is 10-300 nm and dielectric constant is higher than 50. The conductance rate of the liquid dispersing medium is lower than 10?8 S/m, and the dielectric constant is lower than 10. The PM-ER fluids possess the characteristics of high yield strength, high dynamic shear strength, low leakage current, the linear dependence of yield strength on electric field, and high yield strength at low electric field, etc. The yield strength improves to almost 100 times of that of ordinary ER fluids and reaches to more than 200 Kpa.

Abstract: Polar molecules dominated electrorheological fluids mainly comprising a mixture of dispersed phase of solid particles and/or dispersing liquid medium. The dispersed phase solid particles, on the surface, or the liquid dispersing medium contain polar molecules or polar groups, the dipole moment of which is 0.5-10 deb and the size is between 0.1 nm and 0.8 nm. Dispersed phase solid particles are spherical or nearly spherical, of which the size is 10-300 nm and dielectric constant is higher than 50. The conductance rate of the liquid dispersing medium is lower than 10?8 S/m, and the dielectric constant is lower than 10. The PM-ER fluids possess the characteristics of high yield strength, high dynamic shear strength, low leakage current, the linear dependence of yield strength on electric field, and high yield strength at low electric field, etc. The yield strength improves to almost 100 times of that of ordinary ER fluids and reaches to more than 200 Kpa.

Abstract: The invention relates to modified electrodes for ER fluids prepared by adding a rough, wear-resisting, and low conductive modified layer on the surface of metallic electrodes. The material for the modified layer can be at least one from diamond, alumina, titanium dioxide, carborundum, titanium nitride, nylon, polytetrafluoroethylene, adhesive, and adhesive film. Through the addition of the modified layer, the adhesion of the ER fluid to electrodes is increased so that the shear stress measured near the plates is close to the intrinsic value, which makes the ER fluid applicable, while reducing the leakage current and increasing the breakdown voltage of the ER fluid equipment.