38 results about "Polarization impedance" patented technology

The invention relates to the field of medical instruments, discloses a dual-electrode combined member and a stimulation system, and aims at stimulating deep tissues, controllably stimulating two tissues and reducing tissue reaction and polarization impedance. The dual-electrode combined member comprises a screw type electrode or a spindle type electrode and a spiral electrode. The dual-electrode combined member, a stimulation generator and lead bodies form the stimulation system. The stimulation generator comprises a dual pulse output circuit (simply named "dual-core" heart pacemaker when it is used for the heart), and a new simulation mode through which electric pulses of opposite directions are alternately emitted is provided. The dual-electrode combined member and the stimulation system are preferably used for the ventricular septum to perform cardiac resynchronization therapy; and two brand-new cardiac synchronization modes are put forward: one mode is that left and right ventricular electrical stimulation pulses are emitted to control double ventricular electro-mechanical activity; and the other mode is that the cardiac muscle between the cathode and the anode in the ventricular septum is stimulated so that excitation is enabled to be spread to both ventricles from the ventricular septum.

Methods and apparatus for controlling a catalytic layer deposition process are provided. A feed stream comprising a carbon source is provided to a catalyst layer. An asymmetrical alternating current is applied to the catalyst layer. A polarization impedance of the catalyst layer is monitored. The polarization impedance can be controlled by varying the asymmetrical alternating current. The controlling of the polarization impedance provides control over the structure and amount of carbon particles deposited on the catalyst layer. The carbon particles may be in the form of nanotubes, fullerenes, and / or nanoparticles.

The present invention provides methods and apparatus for controlling catalytic processes, including catalyst regeneration and soot elimination. An alternating current is applied to a catalyst layer and a polarization impedance of the catalyst layer is monitored. The polarization impedance may be controlled by varying the asymmetrical alternating current. At least one of water, oxygen, steam and heat may be provided to the catalyst layer to enhance an oxidation reaction for soot elimination and / or to regenerate the catalyst.

The invention discloses a novel high-performance solid oxide electrolytic tank support which belongs to the technical field of a solid oxide electrolytic tank. The support is provided with a continuous gradient porous structure with the porosity of 60%-80%. A support preparation method comprises the following steps of: preparing water-based paste by using 8YSZ powder or NiO-8YSZ as a solid material and an ammonium polyacrylate dispersing agent and a water-based emulsion bonding agent, molding through the combination of a freezing pouring process and a freeze drying method, and finally sintering at high temperature to obtain the target support. As the support is provided with the continuous gradient porous structure, the area of the three-phase interface is greatly enlarged, meanwhile, the resistance of gas diffusing toward the surface of electrolyte from the surface of an electrode is reduced, and therefore, the polarization impedance of a solid oxide battery can be greatly reduced, thus the performance of the solid oxide battery is improved. The method has the advantages of simple operation, flexibility, controllable pore passage morphology and the like.

The invention relates to a preparation method of a nanofiber composite negative electrode of an intermediate-temperature solid oxide fuel cell, belonging to the technical field of energy materials. The preparation method comprises the following steps: firstly preparing a mixed spinning solution containing perovskite structured oxide components and oxygen ion conductor electrolyte components, spinning the mixed solution by virtue of an electrospinning technique to prepare composite fiber, drying and carrying out high-temperature sintering, so as to obtain nanofiber structured composite negative electrode. The diameter of the composite negative electrode fiber is 100-600 nanometers; nanofiber is formed by virtue of agglomeration of perovskite oxide components and electrolyte component nano-particles, wherein the mass percent of the perovskite oxide components is 45%-65%. Components in the nanofiber negative electrode are uniformly distributed, so that the transmission of ions and electrons is benefited; the activation area of electrochemical reaction and the interface of three-phase reaction are large, so that the oxygen reduction catalytic activity of the negative electrode is improved, and the polarization impedance of the negative electrode is reduced; furthermore, the preparation process is simple, the operation is easy, and the cost is low.

The invention discloses an impedance measurement system and method for secondary batteries and belongs to a battery measurement technology. The system comprises a battery module, a charging and discharging module, an alternating current frequency scanning module and a signal collecting and processing module. A 203c point of a 203 three-position switch of the charging and discharging circuit is connected with the negative electrode of the battery module 1, and by selecting a switch arm connected with the 203c point, the negative electrode of the battery module 1 is connected with a 202 electronic load and the positive electrode of the battery module 1 through a 203a point to form a discharging circuit. The impedance measurement system and method for the secondary batteries are applied to tests on impedance of the secondary batteries in the working state and can be used for measuring all the single secondary batteries contained in a secondary battery pack in parallel through multiple channels. The Ohm internal resistance, the electrochemical polarization impedance and the concentration polarization impedance of each secondary battery are tested out, the impedance of each secondary battery is analyzed, and the impedance measurement system and method are used for analyzing the charging and discharging performance of the batteries. The service life of the batteries is estimated, and the batteries can run more safely, stably and reliably.

The invention discloses a measurement method of the electrical conductivity of a solution stimulated by sine wave superimposed signals of two frequencies. Two sine wave superimposed signals are used to stimulate an electrode. Electrode response current is filtered through two channels. One channel carries out low pass filtering to precipitate a sine wave signal of a low frequency component. The other channel carries out high pass filtering (or band pass filtering) to precipitate a sine wave signal of a high frequency component. Amplitude and phase detection are respectively carried out on the sine wave signal of the low frequency component and the sine wave signal of the high frequency component, wherein the signals are precipitated by two channels. By combining the parameters of the stimulating signals and detected amplitude and phase of the response current with an electrical conductivity cell equivalent physical model, a joint equation is listed and is solved to acquire Rx, wherein the resistance Rx of the solution to be measured, the electrode distribution capacitance Cp, the electrode polarization impedance, the double electrical layer capacitance Cx of the electrode are unknowns of the joint equation. Electrode constants are combined to calculate the electrical conductivity of the solution. According to the technical scheme, the effects of the electrode distribution capacitance, the electrode polarization impedance and the double electrical layer capacitance of the electrode on measurement can be removed.