41 results about "Concentration polarization" patented technology

The invention discloses a reverse osmosis membrane concentration polarization layer thickness prediction method and device based on electrical impedance tomography, and relates to the technical field of membrane process nondestructive monitoring, and the method comprises the following steps: constructing a simulation model based on an electrode array membrane filtration sensor; virtual media with different conductivities are arranged on the surface of the membrane, a simulation conductivity image is reconstructed through a conjugate gradient least square algorithm and a sensitivity matrix, and a neural network is improved through known conductivity training; and reconstructing an actually measured conductivity image by an actually measured boundary voltage data set, predicting a membrane surface conductivity estimated value by using the trained improved neural network, and performing concentration polarization layer thickness mapping. A conductivity image with a conductivity label is generated through numerical simulation, so that the problem that the thickness of the concentration polarization layer is difficult to calibrate is solved, then a neural network is improved through training so that the truth value of the conductivity can be predicted according to the conductivity image, and interpretable mapping of the thickness of the concentration polarization layer is carried out in combination with a membrane mass transfer theory. The thickness of the concentration polarization layer can be subjected to online lossless quantitative detection.

The invention relates to the technical field of fuel cell state evaluation, in particular to a fuel cell health state estimation method and system, and the method comprises the steps: continuously collecting the monomer polarization curve, pile AC impedance spectrum and gas flow channel pressure pulsation time sequence data of a target fuel cell in multiple operation cycles; ohm, activation and concentration polarization component decomposition are carried out on the polarization curve, a corresponding voltage loss component is extracted, correlation matching calculation is carried out on the corresponding voltage loss component and an impedance spectrum, and a polarization loss-impedance characteristic mapping relation is constructed. And extracting a pressure fluctuation mode synchronous with the polarization curve time sequence, and identifying an extra concentration difference loss component caused by the gas diffusion barrier by correlating the concentration difference polarization loss voltage. And integrating the component, the mapping relation and a reference aging model to calculate a comprehensive health state index. The multi-aging superposition state of the membrane electrode, the proton exchange membrane and the gas diffusion layer can be accurately reflected, aging inducement distinguishing is refined, and the accuracy of health state characterization is improved.

The application discloses an electro-catalytic oxidation system and method and an ecological joint treatment method for in-situ remediation of water body sediments, which utilizes an intelligent pulse power controller to perform intermittent pulse electro-catalytic oxidation on the bottom mud at the water bottom, generates hydroxyl radicals through in-situ catalysis of an anode to degrade organic pollutants of the bottom mud, generates micro-bubbles in the interstices of the bottom mud through the electrolysis of water to improve the oxidation-reduction potential, and further reserves time for the soluble pollutants in the interstitial water of the bottom mud to sufficiently diffuse to the surface of the electrode, so as to avoid energy waste caused by concentration polarization. Through reverse power supply, the polarity of the anode and the cathode is instantaneously reversed, trace amounts of acidic substances and gas generated through in-situ electrolysis are utilized to strip off the calcium and magnesium scale attached to the surface of the cathode, and manual cleaning and maintenance under water are realized. In combination with the planting of submerged plants on the treated bottom mud, ecological joint treatment is realized, the root system of the submerged plants is utilized to perform long-term ecological fixation and water purification on the treated sediments.

The present application relates to the technical field of electrodeposited chromium plating, in particular to a trivalent chromium plating layer with a pearl shell biomimetic structure and a preparation method thereof. By regulating the composition of plating solution and electrodeposition process, stable periodic concentration polarization is induced to form potential composition distribution along the thickness direction of amorphous precursor plating layer; after annealing at 350-450 DEG C for 0.5-1 h, the potential composition modulation is explicit and phase transition occurs, and the pearl shell biomimetic layered structure is constructed in situ. The plating layer presents a periodic and alternating arrangement of natural pearl shell "hard-soft" multilayer stacked biomimetic layered structure in microcosm, wherein the chromium layer is a metallic chromium crystalline layer with a thickness of 5-30 nm; the carbon / carbon-chromium mixture layer is amorphous or nanocrystalline with carbon enrichment and in-situ formed chromium carbide phase, with a thickness of 1-3 nm. The total thickness of the plating layer is 5-30 microns, and the number of layers reaches 300-1800 layers. The structure can hinder crack propagation and improve load transfer, so that the plating layer has high hardness and wear resistance. Moreover, the process is environmentally friendly and controllable, and is suitable for mechanical parts, molds and functional surface protection.

The application discloses an ultrafiltration permeation regulation method and device based on a gradient sponge structure dialysis membrane and relates to the technical field of hemodialysis. An intelligent response membrane assembly containing a nonlinear aperture gradient is constructed; a signal is collected and a concentration polarization critical index is calculated; when the threshold value is exceeded, a multi-frequency coupling pulse control instruction containing a mechanical resonance excitation waveform and a phase reverse matching osmotic pressure oscillation waveform is generated; mechanical resonance excitation is applied to the blood side to induce membrane layer micro-breathing deformation, and an osmotic pressure oscillation waveform is injected into the dialysate side to form a reverse solute diffusion field; microgel deformation feedback signals are monitored in real time, waveform parameters are dynamically adjusted, and the concentration polarization critical index is returned to a safe interval until the ultrafiltration flux is adaptively regulated. The device comprises an intelligent gradient membrane assembly, a fluid power regulation module, an osmotic pressure wave generation module, a sensing feedback array and a central processing unit, can effectively inhibit membrane pollution and concentration polarization, and improves the system operation stability.

The utility model relates to the technical field of sewage treatment equipment, in particular to an automatic control reverse osmosis treatment device, which comprises first reverse osmosis equipment and second reverse osmosis equipment, the first reverse osmosis equipment comprises an osmosis bin, an osmosis membrane body arranged in the osmosis bin and a central pipe arranged in the osmosis membrane body, a water purification hole is formed in the central pipe, the central pipe is communicated with the permeable membrane body, the permeable membrane body divides the permeable bin into a fresh water area and a concentrated water area, the permeable bin is provided with a water inlet communicated with the fresh water area, the permeable bin is provided with a water outlet communicated with the concentrated water area, and the water outlet is in pipeline connection with a conductivity sensor. The water inlet is connected with a high-pressure pump through a pipeline, and the high-pressure pump is electrically connected with the conductivity sensor; the reverse osmosis membrane accurately controls the flow of a concentrated water area, effectively prevents impurities from forming a concentration polarization layer on the surface of the reverse osmosis membrane body, prevents the impurities from depositing into an irreversible pollution layer, and prolongs the service life of the reverse osmosis membrane body.

The application discloses the technical field of electroplating wastewater treatment high-value metal recovery system for electroplating wastewater, including electrolytic cell and electrolytic mechanism, electrolytic cell is connected with infusion tube, infusion tube is connected with electronic flowmeter, electrolytic cell top is detachably connected with cover body, cover body is provided with observation ring groove, cover body is fixedly connected with camera unit; The inside lower side of the electrolytic cell is provided with a sedimentation plate and a stirring unit, the sedimentation plate is in sliding fit with the inner side wall of the electrolytic cell, the bottom of the electrolytic cell is fixedly connected with a first weighing sensor, and the detection end of the first weighing sensor is in abutment with the bottom of the sedimentation plate; The electrolytic mechanism includes a controller, a driving unit, an adjusting unit and an electrolytic unit. The application reduces the generation of concentration polarization and activation polarization phenomenon in the process of electroplating wastewater metal treatment and recovery, recovers the wastewater metal in an efficient state, estimates the treatment and recovery effect of the wastewater metal, and improves the qualified rate of wastewater metal treatment and recovery.

This invention relates to the field of separation membrane technology, and particularly to a photothermal nanofiber membrane capable of retaining volatile organic compounds (VOCs), its preparation method, and its applications. This photothermal nanofiber membrane employs a multi-structure synergistic design to comprehensively optimize the overall performance of membrane distillation. In the gradient wettability structure of the photothermal nanofiber membrane, the hydrophobic layer, with its low thermal conductivity, suppresses heat conduction loss and alleviates temperature polarization; the hydrophilic layer, through its hydration effect, suppresses solute enrichment and alleviates concentration polarization; the nano-thin-coated PDA photothermal layer achieves efficient photothermal conversion through the light trapping effect, while simultaneously providing sufficient anchoring points for the loaded defective UiO-66 nanoparticles; the synergistic effect of each functional layer achieves multifunctional integration of thermal management, anti-fouling, photothermal conversion, and VOCs retention, comprehensively improving the operating efficiency and stability of the membrane distillation system. The preparation method provided by this invention offers strong process controllability and possesses good reproducibility and potential for large-scale application.

The utility model provides a flat plate electroplating bath device for electrolytic copper foil, which comprises an electroplating component, the electroplating component comprises an electroplating bath body, a mounting piece and an electrode plate, and the electrode plate is fixed in the electroplating bath body through the mounting piece; the electrode plates comprise a cathode plate and an anode plate; two sides of the cathode plate and the back surface far away from the anode plate are tightly attached to the inner wall of the mounting piece or the electroplating bath body. According to the utility model, the problems of concentration polarization and flow field distribution on the surface of the cathode in the use process of the flat plate electroplating bath are solved, so that the reliability of experimental data of the flat plate electroplating bath is improved, and the research and development efficiency of electrolytic copper foil is improved.

This invention discloses a simulation method for a real-size mesh channel reverse electrodialysis power generation process, comprising the following steps: S1, simplifying the real mesh channel into a two-dimensional zigzag circular mesh using the flow resistance method, and calculating the equivalent radius of the two-dimensional mesh according to the area equivalence principle; S2, selecting the smallest periodic unit membrane pair for modeling on the x-y plane, dividing the mesh, and setting membrane and solution properties, operating parameters, and boundary conditions; S3, extending the multiphysics field changes to the entire membrane pair height using the boundary coupling method; S4, calculating the membrane-side diffusion boundary layer thickness and potential abrupt change, solving for the resistance of each part of the system, and evaluating the impact of concentration polarization and ion short-circuit current on the output power. The real-size mesh channel reverse electrodialysis power generation process simulation method disclosed in this invention achieves the continuity of multiphysics field changes in the entire flow channel from the membrane pair inlet to the outlet through the boundary coupling method.

The utility model discloses special equipment for finishing screw heads, which relates to the technical field of screw head finishing and comprises a base, an electroplating tank is fixedly mounted on the top surface of the base, electric telescopic rods are fixedly mounted on two outer sides of the electroplating tank, and an assembly plate is fixedly mounted at the top end of each electric telescopic rod. The rotating shaft rotates to drive the cam to rotate, and the spring telescopic rod is matched to drive the electroplating basket to vibrate up and down in a reciprocating manner, so that the contact area between the screw head and electrolyte is increased, the electroplating uniformity of the screw head is improved, self-circulation of the electrolyte in an electroplating tank is realized, the flowing of the electrolyte is increased, and the concentration polarization phenomenon of the electrolyte can be effectively avoided.

The utility model provides a tubular microfiltration membrane and a reaction tank. According to the micro-filtration membrane, the spiral guide sheets are arranged in the membrane tube main body to guide the tubular bundling separation membrane to spirally extend, so that a rotational flow effect is formed to break through a traditional straight-through flow channel mode, the turbulence degree of fluid is enhanced, and concentration polarization is reduced. The split type design is adopted in the structure, an upper shell and a lower shell are welded and formed, end covers at the two ends are assembled with connecting grooves through clamping blocks, a rubber plate with holes fixes a film bundle through holes, clamping grooves in the edges of the rubber plate are embedded into grooves of guide pieces to prevent flow channel bias flow, and an additionally-arranged axial flow disturbing rod and a spiral flow channel cooperate to generate multi-stage eddy currents to strengthen boundary layer disturbance. The composite supporting structure is composed of a stainless steel wire net and a gradient pore ceramic frame, the outer net improves the mechanical strength, the inner layer ceramic frame adopts 35-60% radial gradient pore distribution to achieve progressive throttling, the transmembrane pressure difference is optimized, and membrane wires are protected.

The invention discloses a method for improving the capacitive deionization performance of a flow electrode, and belongs to the technical field of capacitive deionization of the flow electrode. Ultrasonic action is added in a system, ultrasonic waves generated by an ultrasonic transducer are transmitted to a flow channel through a graphite collector plate, and the laminar flow state is broken through sound streams, shock waves and micro jet flow formed by the ultrasonic cavitation effect, so that the capacitive deionization performance of the flow electrode is improved. The fluid is more turbulent; meanwhile, snakelike runners on the graphite collector plates can avoid channeling and dead zones, so that flowing electrode liquid is distributed more uniformly, and concentration polarization is further reduced; the ion adsorption rate of the electrode is improved, and the electrode is especially suitable for high-concentration seawater desalination and other scenes with high efficiency requirements; the flowing electrode liquid circulates in a short-circuit mode, the electrode liquid on the two sides flows into the same container to be mixed and reused after leaving the module, electrode regeneration can be synchronously completed without independently setting a desorption step, and the time for shutdown regeneration is saved.

This invention relates to the field of HDI board electroplating technology, specifically to an HDI board electroplating device, comprising: an electroplating tank containing an electrolyte and a copper block, and a high-speed power supply acting on the electrolyte and the copper block; and an electrolyte flow assembly including an upper fixed box symmetrically arranged inside the electroplating tank, with multiple first through holes, second through holes, and third through holes vertically formed on both sides of the upper fixed box. This invention achieves bidirectional flow control of the electrolyte flow assembly, generating a high-speed turbulent flow of 5-7 m / s during the forward flow phase, significantly improving the electrolyte exchange efficiency at the bottom of blind holes, stabilizing the copper ion concentration at 80-120 g / L or higher, and effectively suppressing concentration polarization. During reverse flow, a flow rate of 3-5 m / s removes residual impurities and bubbles from the holes, and with the injection of a protective agent, prevents abnormal thickening of the copper layer at the hole opening.

The application discloses a novel tubular membrane module and belongs to the chemical industry. One end of the membrane module is a head, the other end is a cover, and a plurality of tubular membranes are arranged in the inner cavity of the membrane module. The tubular membranes are fixed through a tube plate, the two ends of the tubular membranes are provided with sealing gaskets, the head is provided with a permeate pipe, a retentate outlet is located at the upper end of the shell side where the tubular membranes are arranged, and a raw material inlet pipe is located in the inner cavity of the membrane module. The structure design of the application is ingenious, can not only increase the turbulent degree of fluid in the module, make the mixing degree of raw materials in the module higher, reduce the volume of the stagnant zone in the membrane module, improve the utilization rate of the membrane module, and reduce the pressure loss, but also can reduce the concentration polarization phenomenon of the membrane, improve the mass transfer effect, and achieve the purpose of improving the performance of the membrane.

The invention discloses a negative pole piece and an electrochemical device and an electronic device comprising the same, and belongs to the technical field of energy storage. The negative pole piece comprises a negative current collector and a negative active material layer arranged on at least one surface of the negative current collector; the negative electrode active material layer comprises a bottom layer, a middle layer and a surface layer which are sequentially arranged on the surface of the negative electrode current collector, the bottom layer comprises a three-dimensional carbon material, the middle layer comprises a two-dimensional carbon material, and the surface layer comprises a one-dimensional carbon material; the thickness of the bottom layer, the thickness of the middle layer and the thickness of the surface layer are H3, H2 and H1 respectively, and the formula that H1: H2: H3 = (0.5-2): (1-3): (5-10) is met. According to the present invention, by constructing the continuous Li < + > transmission channel from the surface layer to the bottom layer, the Li < + > is not easily accumulated at the interface, such that the concentration polarization is reduced, the charge transmission dynamics is improved, and the cycle performance of the electrochemical device is improved.

The utility model discloses a catholyte full-flow circulation electrolytic manganese system, which belongs to the technical field of hydrometallurgy and comprises an electrolytic bath, a cathode plate, an anode plate, a conductive copper bar, a diaphragm bag, a catholyte circulating tank, a catholyte circulating pump and a catholyte head tank, the conductive copper bar is arranged at the top end of the electrolytic bath, and the cathode plate and the anode plate are mounted on the conductive copper bar at intervals. The cathode plate and the anode plate extend into the electrolyte; the diaphragm bag sleeves the cathode plate inside to form a cathode region, an anode region is formed around the anode plate, and the cathode region, the catholyte circulating tank, the catholyte circulating pump, the catholyte elevated tank and the cathode region are sequentially communicated to form a catholyte circulating path. In the manganese electrolysis process, catholyte can be circulated in the whole process, the problems that the liquidity of liquid in the cathode area is poor, the concentration polarization phenomenon is prone to occurring and the like are effectively solved, the liquidity of the liquid in the cathode area can be improved, the tank temperature can be better controlled, and the device is suitable for large-scale production.

This invention discloses a method for preparing a liquid-solid two-phase electrolyte, comprising: S1, mixing a zinc salt aqueous solution A with natural gum, and obtaining a solid zinc salt complex after thorough complexation and post-treatment; S2, thoroughly mixing the solid zinc salt complex with a zinc salt aqueous solution B to obtain the liquid-solid two-phase electrolyte. In the liquid-solid two-phase electrolyte prepared by this invention, the natural gum can spontaneously form a natural gum zinc salt complex with zinc ions in the electrolyte environment. This complex, added as a solid phase to the electrolyte, plays a dynamic role in the formation of zinc salts. 2+ The reservoir's function is to continuously release Zn to the interface through coordination-dissociation equilibrium. 2+ This approach alleviates concentration polarization at its source, suppressing dendrite formation and other side reactions. Simultaneously, it reconstructs the hydrogen bond network to reduce H2O activity, releasing natural gum molecules adsorbed on the (002) crystal surface of the zinc anode and regulating the double-layer structure. Aqueous zinc-ion batteries assembled with this liquid-solid two-phase electrolyte exhibit significantly extended lifespan.

The utility model relates to nickel electrolysis technical field, concretely relates to a kind of nickel electrolysis test device of continuous operation, to solve the problem that current laboratory nickel electrolysis device is mainly intermittent operation, cannot simulate industrialization continuous production, while current efficiency and deposition rate are low.The cathode and anode of the device mainly function as electron conduction, oxidation-reduction reaction occurs, high-frequency rectifier can provide stable electrolysis voltage and electrolysis current, water bath and electric heating plate ensure that electrolysis temperature is constant, high tank, constant current pump and liquid storage tank can maintain electrolyte flow, avoid concentration polarization, affect current efficiency and deposition rate, this set can simulate field production conditions and carry out nickel electrolysis test, significantly reduce the research and development cost and risk of industrialization amplification, realize the effect of laboratory nickel electrolysis device continuous production.

A solution electrolysis device for hydrometallurgy comprises a solution electrolysis system and an electrolyte circulating filtration system, the solution electrolysis system comprises a tank body, an electrolyte outlet and an electrolyte inlet are formed in the two opposite sides of the tank body respectively, the inlet and the outlet of the electrolyte circulating filtration system are communicated with the electrolyte outlet and the electrolyte inlet respectively, and the top of the tank body is open. A plurality of partition plates are arranged at the bottom of the tank body and between the electrolyte inlet and the electrolyte outlet, the partition plates divide the interior of the tank body into a plurality of electrolysis areas, the upper sides of the electrolysis areas are communicated with one another, and the anode plates and the cathode plates are sequentially and alternately mounted in the tank body from the electrolyte inlet to the electrolyte outlet; according to the device, the concentration polarization phenomenon generated when valuable metal is extracted from a complex acid solution through electrolytic deposition is restrained, the problem of solid-phase deposition in the electrolytic bath is solved, and the device is simple in structure, convenient to operate and high in practicability. And the current efficiency and the metal yield are improved.

This invention relates to the field of membrane separation technology, specifically a method for preparing double-skin forward osmosis membranes with different densities on both surfaces of a support in a one-step process. This invention optimizes existing methods for preparing double-skin polyamide forward osmosis membranes, enabling the preparation of double-skin polyamide forward osmosis membranes with different densities through a single-step interfacial polymerization process. This method alleviates concentration polarization while increasing the flux of the double-skin forward osmosis membrane.

The present application relates to a kind of sodium ion solid electrolyte material of dual-phase structure and its preparation method and application, it simultaneously exists rhombic phase and monoclinic phase at 25 ℃~35 ℃, and it is atom level between two phases Binding;Its nominal composition Na 3+a Zr 2‑x‑y Sc x M y Si2PO 12 Wherein, M is other metal elements except Na, Zr and Sc, 0≤a≤0.5, 0.1≤x≤0.5, 0.3≤x+y≤1.2.The present application can promote the configuration entropy of sodium ion solid electrolyte material by introducing Sc and other metal elements except Na to replace part of Zr element in crystal lattice, make the rhombic phase of high ionic conductivity stable exist at room temperature and combine with monoclinic phase through superlattice structure, improve bulk conductivity at room temperature.In practical application, it can be used as positive electrode filler, reduce concentration polarization, improve the kinetic performance of thick electrode, significantly improve its rate performance.

The invention discloses a structural design method of an anion exchange membrane stack, which comprises the following steps: designing a layered bipolar flow channel, configuring a dynamic water management module, setting an interface impedance regulation and control layer, improving reactant flow field distribution through the layered bipolar flow channel, and regulating the internal humidity and pressure of the stack in real time by the dynamic water management module. The interface impedance regulation and control layer reduces the membrane-electrode interface contact impedance, and collaborative optimization of the stack performance is realized; the method solves the problems of concentration polarization, water management imbalance and interface impedance superposition of the existing stack, improves the output stability of the stack, prolongs the service life of the stack, and is suitable for anion exchange membrane stack application scenes of fuel cells, electrolyzed water and the like.

The present application relates to the technical field of comprehensive utilization of waste heat, and discloses a salinity gradient power generation apparatus and method, and a water-electricity co-generation apparatus thereof. In the salinity gradient power generation apparatus and method provided in the present application, an anode and a cathode respectively undergo hydrogen oxidation and reduction reactions, the anode consumes hydrogen, the cathode generates hydrogen, and the hydrogen circulates between the cathode and the anode by means of pipes without net consumption, thereby efficiently utilizing salinity gradient energy, achieving an environmentally friendly process, and producing no carbon emissions; compared with redox reaction systems using Fe2+ / Fe3+ or ferricyanide / ferrocyanide, the system is free from the limitation of concentration polarization; compared with redox systems based on water electrolysis, lower overpotential and higher efficiency are achieved; and a small amount of H2 is used, with no safety risk and no net consumption throughout the system. The water-electricity co-generation apparatus based on the salinity gradient power generation apparatus of the present application can make full use of waste heat to produce fresh water and generate electricity simultaneously, achieving high efficiency and pollution-free operation.

The invention belongs to the technical field of steel and iron material surface treatment, and particularly relates to a steel and iron material surface composite coating preparation method which comprises the following steps: adding a main salt, a water repellent agent and a nanotube material loaded with a low-surface-energy substance into a deep eutectic solvent to prepare a plating solution; the composite coating with the hydrophobic performance is prepared on the surface of a steel material in a pulse electrodeposition mode through a one-step method. The method has the advantages that the deep eutectic solvent plating solution system is adopted for preparing the composite coating, and the defects that a traditional aqueous solution electroplating system is narrow in process window, inflexible in coating composition regulation and control and the like are overcome while the plating solution has the remarkable environment-friendly characteristic. Compared with direct-current electrodeposition, the pulse electrodeposition process can remarkably improve the dispersing capacity of the plating solution, inhibit concentration polarization of the plating solution and improve the quality of a plating layer; according to the preparation method of the composite coating, doping of the hydrophobic agent and the tubular nanometer material loaded with the low-surface-energy substance in the coating can be achieved in one step, and therefore the surface of a steel material is endowed with the super-hydrophobic function.

The present application relates to the technical field of hydrogen production material by electrolysis of water, in particular to a Ni-based noble metal monatomic catalyst, a preparation method and application thereof; the Ni-based noble metal monatomic catalyst takes carbon paper as a substrate, and is obtained by one-step single-pulse in-situ electrodeposition on the pretreated carbon paper. The single-stage pulse deposition method controls the deposition potential, pulse interval, duty cycle and addition of complex, and weakens the influence of concentration polarization on metal ion reduction, thereby obtaining different noble metal monatomic. The present application can obtain different noble metal monatomic with ultra-low loading, realize rapid and large-scale preparation, and provide a preparation strategy of high-activity and low-cost hydrogen evolution catalyst, which has excellent hydrogen evolution activity and good durability under alkaline conditions, and has great application prospect.

The invention discloses a method for improving the service stability of a nanofiltration membrane and application, and belongs to the technical field of nanofiltration. The method comprises the following steps: carrying out magnesium-lithium separation on the salt lake brine with the high magnesium-lithium ratio by adopting a nanofiltration technology, and regulating and controlling the membrane surface flow rate, the operation pressure and the feeding temperature; wherein the flow rate of the salt lake brine flowing through the membrane surface of the nanofiltration membrane is 0.062-0.714 m < 3 > / h, the operation pressure is 0.1-4 MPa, and the feeding temperature is 10-40 DEG C. The influence of concentration polarization on the nanofiltration membrane is relieved by adjusting conditions such as temperature, membrane surface flow velocity and pressure in the separation process, so that the service stability of the nanofiltration membrane is improved; meanwhile, the performance of the nanofiltration membrane is recovered by combining a hydraulic-weak base-weak acid cleaning method, so that the service stability and the service life of the nanofiltration membrane in the magnesium-lithium separation process of the salt lake brine with the high magnesium-lithium ratio are improved.

The invention provides a ferronickel-based self-supporting oxygen evolution electrode and a preparation method thereof. The preparation method comprises the following steps: S1, adding ferric salt, nickel salt and an additive into a solvent to obtain a metal seed solution; s2, an electrode substrate is placed in the metal seed solution, the surface of the electrode substrate is heated at the initial pH at the heating rate of 0.7-2.5 DEG C / min to form an iron-rich phase, when the pH reaches 6.5-7.5, a nickel-based transition layer is formed on the surface of the iron-rich phase at the heating rate of 0.1-0.7 DEG C / min, and when the pH reaches 7.5-8, the nickel-based transition layer is formed on the surface of the iron-rich phase at the heating rate of 0.1-0.7 DEG C / min; and stopping heating and carrying out heat preservation reaction to form the ferro-nickel layered double hydroxide on the surface of the nickel-based transition layer. The controllable preparation of the high-performance self-supporting electrode is realized by accurately controlling the hydrothermal reaction process, the pores of the three-layer structure prepared on the surface of the electrode substrate are sequentially increased from inside to outside, the discharge of reactant bodies and products is promoted, compared with the prior art, the ion diffusion path is shortened by the three-layer graded pore channels, the concentration polarization is obviously reduced, and the performance of the electrode is improved. The catalytic activity and the service life are both considered.

The invention relates to the technical field of electroplating, in particular to automobile brake pipe inner wall anti-corrosion electroplating equipment based on pulse current, which comprises an electroplating box, a relay and a swing plate, electric rods are symmetrically and fixedly arranged on the inner walls of the two sides of the electroplating box, the two electric rods are electrically connected with the relay, a switching assembly is arranged on the electroplating box, and the switching assembly is matched with the relay. A switching assembly is arranged on the electroplating box, a swing plate is arranged on the switching assembly, a fan swing assembly is arranged on the electroplating box, the fan swing assembly is matched with the swing plate, a transmission assembly is arranged on the electroplating box, and the transmission assembly is connected with the switching assembly and the fan swing assembly. Positive ions in electroplating liquid are promoted to flow back and forth in the inner wall area of the brake pipe, the problems of concentration polarization and bubble retention easily occurring in traditional static electroplating are effectively solved, the transmission assembly synchronously transmits the switching action to the fan swing assembly, the swing plate is driven to continuously swing in the electroplating box, and periodic surges are generated.

Printed spacer membrane elements offer the unique advantage of applying any pattern on the membrane surface to act as the feed spacer material. This is in contrast to conventional feed spacer mesh material that is uniform in thickness and density throughout the mesh. Concentration polarization is the accumulation of ions or other material at the membrane surface that reduces permeate quality, increases the opportunity for scale and biofilm, reduces recovery, and other deleterious effects. Random or mathematically generated feed space patterns can facilitate fluid mixing in the feed space in order to reduce concentration polarization that occurs at the membrane surface.