111 results about "Mixed potential" patented technology

The invention discloses a mixed-potential type NO2 sensor with a laser-machined YSZ (yttria-stabilized zirconia) substrate serving as a conductive layer and a preparation method for the mixed-potential type NO2 sensor and belongs to the technical field of gas sensors. The mixed-potential type NO2 sensor consists of an Al2O3 ceramic plate with a Pt heating electrode, the YSZ substrate with a mesh-strip structure, a reference electrode and a sensitive electrode, wherein strip-type Pt is adopted as the reference electrode; strip-type NiCr2O4 is adopted as the sensitive electrode; the two electrodes are symmetrically arranged at two ends of the upper surface of the YSZ substrate; the lower surface of the YSZ substrate is adhered to the Al2O3 ceramic plate; a strip distance of the mesh-strip structure is 130-240 microns; the mesh-strip structure is 10-25 microns deep; each strip is 50-80 microns wide; electrode leads are prepared on the reference electrode and the sensitive electrode. The sensor is mainly used for detecting automobile exhaust. Due to the mesh-strip structure on the surface of the YSZ substrate, contact between the gas to be detected and an electrolyte is enlarged, reaction active sites are increased, and the aim of improving the sensitivity of the sensor is fulfilled.

The invention relates to a method for potential controlled selection separation of copper refinery ash. The copper refinery ash is screened and then subjected to oxidizing leaching in a sulfuric acid system. An oxidizing agent is added to control the metal ion mixed potential of slurry, copper, arsenic, zinc and other metal are dissolved into a solution, and lead, bismuth and other metal precipitate and enter leaching residues. The metal ion mixed potential and the pH value of a leachate are simultaneously controlled, so that copper sulfide concentrate is produced through precipitation. The metal ion mixed potential and the pH value of copper-removed liquid are simultaneously controlled, so that arsenic sulfide products are produced through precipitation. The metal ion mixed potential and the pH value of arsenic-removed liquid are simultaneously controlled, so that zinc sulfide concentrate is produced through precipitation. Zinc-removed liquid is subjected to wastewater treatment and then discharged after reaching the standard. According to the method, the potential controlled oxidizing leaching and potential controlled sulfide precipitation ways are simultaneously adopted for recovering valuable metal step by step, the selection separation effect, which cannot be achieved by independently using the ways, of the valuable metal in the copper refinery ash is achieved, and the leaching rates of copper, arsenic and zinc are larger than 98.0%.

In at least one embodiment, a method is described for measuring concentrations of gas moieties in a gas mixture. A mixed-potential gas sensor is exposed to a gas mixture in order to obtain a first and a second mixed-potential gas sensor output responses. The first output response and a second output response are deconvoluted to measure a first analyte gas concentration and a second analyte gas concentration. Some of the output responses may be used as inputs to a control system.

A sensor for determining a concentration of gas components in gas mixtures having a first measuring electrode (mixed potential electrode) which has little or no catalytic effect on the establishment of an equilibrium in the gas mixture and a second measuring electrode (equilibrium electrode) which catalyzes the establishment of an equilibrium in the gas mixture as well as a solid electrolyte that is conductive for oxygen ions arranged between the two measuring electrodes, with the two measuring electrodes being exposed to the gas mixture. At least the first measuring electrode (16) is a cermet electrode, where at least one metal oxide component of the cermet electrode is capable of reversible incorporation of oxygen.

The invention discloses a YSZ (yttria-stabilized zirconia)-based mixed potential type hydrogen sulfide (H2S) sensor with La2NiO4 used as a sensitive electrode and a method for preparing the YSZ-basedmixed potential type hydrogen sulfide sensor, and belongs to the technical field of gas sensors. The YSZ-based mixed potential type hydrogen sulfide sensor is mainly used for detecting toxic gas H2S in industrial production and daily life. The YSZ-based mixed potential type hydrogen sulfide sensor sequentially comprises an Al2O3 ceramic plate with Pt heating electrodes, a YSZ-based plate, a Pt reference electrode and the La2NiO4 sensitive electrode. The reference electrode and the sensitive electrode are independently and symmetrically prepared at two ends of the upper surface of the YSZ-basedplate, and the lower surface of the YSZ-based plate is adhered with the Al2O3 ceramic plate with the Pt heating electrodes. The YSZ-based mixed potential type hydrogen sulfide sensor and the method have the advantages that the La2NiO4 with high electrochemical catalytic activity is used as the sensitive electrode, the quantities of citric acid and the like which are added in material synthesis procedures are changed, accordingly, the electrochemical catalytic activity of sensitive electrode materials can be enhanced, and effects of improving the sensitivity characteristics of the YSZ-based mixed potential type hydrogen sulfide sensor can be realized; a short temperature pulse is applied in sensor recovery procedure, accordingly, the recovery time of the YSZ-based mixed potential type hydrogen sulfide sensor can be shortened, and the purpose of enhancing the response and recovery characteristics of the YSZ-based mixed potential type hydrogen sulfide sensor can be achieved.

A mixed potential sensor for oxidizable or reducible gases and a method of making. A substrate is provided and two electrodes are formed on a first surface of the substrate, each electrode being formed of a different catalytic material selected to produce a differential voltage between the electrodes from electrochemical reactions of the gases catalyzed by the electrode materials. An electrolytic layer of an electrolyte is formed over the electrodes to cover a first portion of the electrodes from direct exposure to the gases with a second portion of the electrodes uncovered for direct exposure to the gases.

A mixed potential sensor device and methods for measuring total ammonia (NH3) concentration in a gas is provided. The gas is first partitioned into two streams directed into two sensing chambers. Each gas stream is conditioned by a specific catalyst system. In one chamber, in some instances at a temperature of at least about 600° C., the gas is treated such that almost all of the ammonia is converted to NOx, and a steady state equilibrium concentration of NO to NO2 is established. In the second chamber, the gas is treated with a catalyst at a lower temperature, preferably less than 450° C. such that most of the ammonia is converted to nitrogen (N2) and steam (H2O). Each gas is passed over a sensing electrode in a mixed potential sensor system that is sensitive to NOx. The difference in the readings of the two gas sensors can provide a measurement of total NH3 concentration in the exhaust gas. The catalyst system also functions to oxidize any unburned hydrocarbons such as CH4, CO, etc., in the gas, and to remove partial contaminants such as SO2.

The invention discloses a method for vulcanizing and separating valuable metal in a solution through controlled potential. The method comprises the steps that 1, alkali and sulfate are simultaneously added into the copper-cobalt-manganese solution to remove calcium in the solution; 2, sodium sulphide is added into the calcium removed solution to enable the mixed potential of metal ions in the solution to be controlled to be a required value, and meanwhile hydrochloric acid is added to adjust the pH value of the solution; 3, after the solution potential is stabilized and continuously stirred, filtering and copper removing are conducted; 4, after coppering removing is completed, the sodium sulphide is added to enable the mixed potential of the metal ions in the solution to be controlled to be the required value, and the hydrochloric acid is added to adjust the pH value; 5, after the solution potential is stabilized and continuously stirred, filtering is conducted; and 6, the pH value of the cobalt removed solution is neutralized through the alkali to reach a required value, the solution is filtered after being stirred, deposited manganese slag is obtained, and selective step-by-step separation of the valuable metal in the solution is achieved. According to the method for vulcanizing and separating the valuable metal in the solution through the controlled potential, selective separation of the valuable metal in the solution is achieved by controlling the mixed potential of the metal ions in the solution and the pH value at the same time; selective separation of the valuable metal in the solution is achieved, and the deposition rate of copper, the deposition rate of cobalt and the deposition rate of manganese are all 99.0% or above.

The invention relates to a large signal stability analysis method for an AC microgrid system considering the dynamic performance of an energy storage system and constant power load. The circuit topology of the AC microgrid is shown in Figure 1. When the energy storage system is in a charging mode, the stability criterion in the charging mode of the storage system can be obtained as follows: C / L1>Pb / V2<2>R1; and when the energy storage system works in a discharging mode, the stability criterion of the energy storage in the charging mode can be obtained as follows: C2 / L1>P2 / V3<2>R1. The AC microgrid is converted into a DC system under a dq rotating coordinate system. The large signal stability criterion is proposed by using a mixed potential function theory. The stability criterion is derived based on the AC microgrid mixed potential function model converted into the DC system. The criterion takes the dynamic performance of the constant power load and the energy storage system into consideration at the same time, gives quantitative constraints on the design of system parameters, ensures the stability of the system under the large disturbance condition and verifies the effectiveness by simulation.

A mixed potential sensor for oxidizable or reducible gases and a method of making. A substrate is provided and two electrodes are formed on a first surface of the substrate, each electrode being formed of a different catalytic material selected to produce a differential voltage between the electrodes from electrochemical reactions of the gases catalyzed by the electrode materials. An electrolytic layer of an electrolyte is formed over the electrodes to cover a first portion of the electrodes from direct exposure to the gases with a second portion of the electrodes uncovered for direct exposure to the gases.

The invention relates to a power electronic power system transient stability analysis method based on a direct method. The method comprises the following steps: 1, determining a system model, 2, constructing a Lyapunov energy function: firstly, establishing a mixed potential function P (i, v) according to a reasonably simplified and determined system model, and secondly, constructing a Lyapunov type energy function of the system in combination with a stability discrimination theorem in a mixed potential function theory, and solving a differential value of the Lyapunov type energy function, andfinally, judging the transient stability of the system through the characteristics of the energy function and the differential value thereof, and 3, estimating the critical energy of the system.