265 results about "Nanofluidics" patented technology

The invention relates to the technical field of silicon waveguide and optical fiber coupling, and particularly provides an AI-based silicon waveguide-optical fiber mode field self-alignment coupling method and system, and the method comprises the steps: monitoring the strain distribution of a chip in real time through an integrated distributed fiber bragg grating array, and obtaining the light field intensity distribution of a coupling region through cooperation with a near-field optical probe array; constructing a deep space-time convolutional network, and generating a deformation compensation vector and a waveguide reconstruction parameter by an output layer; a nanofluid channel is integrated on the side wall of the waveguide, and the refractive index of liquid is adjusted through an electrowetting effect to realize dynamic broadening of a mode field; and the electrostatic driving micro-beam embedded below the waveguide adjusts the spatial pose of the waveguide according to an instruction of an output layer of the depth space-time convolutional network. The system comprises a light field intensity acquisition module, a convolutional network construction module and a spatial pose adjustment module. According to the method, real-time analysis and prediction are performed, so that system parameters are actively adjusted, and alignment precision and stability are improved.

The invention discloses an S-shaped micro-channel heat dissipation device with a double-layer turbulent flow structure and a use method, belongs to the field of liquid cooling heat dissipation, and is suitable for heat dissipation of a high-heat-flux device or a heat conduction device. The device comprises a base, a cover plate, a micro-channel body, turbulent flow columns, a flow guide structure, O-shaped sealing rings and quick-screwing connectors, the micro-channel body is provided with S-shaped channels which are vertically symmetrical, the turbulent flow columns are evenly arranged in the centers of the channels, and the top ends of the turbulent flow columns are flush with the end face of the micro-channel body. The turbulent flow columns can be rectangular columns or water-drop-shaped columns which are arranged in a single row or multiple rows at equal intervals and are matched with the flow guide structure to achieve efficient flow division of cold and hot fluid and interlayer heat interaction. Fluid mixing is strengthened through the centrifugal force of the S-shaped channel, a heat boundary layer is destroyed by the turbulent flow columns, and the problems that a traditional straight channel is low in heat exchange efficiency and uneven in temperature distribution are solved. Deionized water or nanofluid is selected as cooling liquid, closed circulation is formed by entering and exiting of the cooling liquid through the quick-screwing connector, and the adaptive scene and the comprehensive performance of the device are further expanded through the multiple rows of turbulent flow columns or the water-drop-shaped turbulent flow columns.

The invention relates to an enhanced urban terrestrial heat exploitation system and method based on nanofluid. The system comprises a heat collection pipeline, a heat exchange assembly and a nanofluid adjusting assembly. The nanofluid adjusting assembly is connected into the heat collecting pipeline. The nanofluid adjusting assembly comprises a storage pool, a control unit, a concentration detection sensor, a temperature sensor and a concentration adjusting unit, the concentration detection sensor, the temperature sensor and the concentration adjusting unit are connected with the control unit, the storage pool communicates with the heat collecting pipeline, the concentration detection sensor is used for detecting the concentration of nanofluid in the storage pool, and the temperature sensor is used for detecting the temperature of the nanofluid. And the concentration adjusting unit is used for adjusting the concentration of the nanofluid in the storage tank. Compared with the prior art, the method has the advantages that the fluid concentration in the whole circulation pipeline is adjusted in real time according to the appropriate heat transfer concentration of the hybrid nanofluid at all temperatures, then the heat exchange performance of the nanofluid is effectively guaranteed, and the heat exchange efficiency of the geothermal circulation system is improved.

The invention discloses a low-temperature-rise, high-impermeability and low-carbon concrete nano-fluid additive as well as a preparation method and application thereof, and relates to the technical field of graphene materials. The nanofluid additive comprises water and graphene and a dispersing agent which are dispersed in the water, the dispersing agent comprises polyvinyl alcohol and / or sodium carboxymethyl cellulose, and the preparation method comprises the following steps: adding graphite powder into a dispersing agent solution, and then sequentially carrying out shearing stripping and emulsifying stripping to obtain a mixed solution; and centrifuging the mixed solution, and collecting the supernatant to obtain the nanofluid additive. The graphene nanofluid is added into the cement-based material as an additive, can effectively absorb and disperse hydration heat release in the cement hydration process, and slows down the hydration reaction rate, so that the overall hydration heat is reduced. Meanwhile, the high surface area and the two-dimensional structure of the graphene are beneficial to filling micro-pores of the cement-based material, and the impermeability, the durability and the mechanical property of the cement-based material are improved.

The invention relates to the technical field of heat dissipation of electronic devices, in particular to a multi-objective optimization method for a microchannel heat sink turbulent flow structure based on nanofluid. The multi-objective optimization method comprises the steps that integrated computational fluid mechanics simulation, a response surface method and an NSGA-II algorithm are matched; the system solves the problems that in the prior art, research on the synergistic effect of a nanofluid and a turbulent flow structure is insufficient, and multi-objective optimization efficiency is low, firstly, a three-dimensional numerical model is constructed based on ANSYS, and heat transfer and pressure drop characteristics under different parameters are simulated and quantified; secondly, establishing a mathematical model of an input parameter and an output target by adopting a response surface method, and revealing a multi-parameter coupling rule; and finally, performing multi-objective optimization on the synergistic effect by using an NSGA-II algorithm, obtaining a Pareto optimal solution set, and realizing the optimal balance of the heat dissipation performance and the voltage drop. By adopting the technical scheme, through combination of numerical simulation and experimental verification, the optimization efficiency is remarkably improved, and the optimization cost is reduced. And a solution with theoretical preciseness and engineering practicability is provided for thermal management of high-power electronic devices.

The embodiment of the invention relates to the technical field of nanofluid preparation, in particular to a nanofluid preparation method which is used for mixing metal nanoparticles and alkali metal to form nanofluid and comprises the steps that S1, the metal nanoparticles are coated with solid alkali metal so as to form an integrated piece with the solid alkali metal; s2, adding the integrated piece into liquid alkali metal; and S3, uniformly mixing the integrated piece with liquid alkali metal to form the nanofluid. According to the embodiment of the invention, the nanoparticles are coated with the solid alkali metal to form the integrated piece, and then the integrated piece is added into the liquid alkali metal, so that the metal nanoparticles can be prevented from being adsorbed on the inner wall of a container or a pipeline, and the situation that the ratio of the metal nanoparticles to the alkali metal is not accurate can be avoided.

The invention relates to the technical field of phase change heat storage, in particular to a simulation method for enhancing a lung groove imitating blood vessel fin phase change heat storage system through nanofluid. The method comprises the following steps: firstly, establishing a three-dimensional physical model of the phase change heat storage enhanced heat transfer system simulating lung groove blood vessel fins, performing simulation analysis on the three-dimensional model, comparing a simulation result with an experimental result, and adjusting parameters of the simulation model to improve the accuracy of the simulation result; different nano-fluids are selected through the optimized simulation analysis platform to carry out enhanced heat transfer research on the TES, and the influence of the volume fraction of the nano-particles, the variety of the nano-particles, the temperature of the heat transfer fluid (HTF) and the initial speed on liquid phase distribution, temperature distribution, melting characteristics and kinetic energy consumption of the TES is analyzed. And finally, performing three-objective optimization on the kinetic energy, the TES heat storage amount and the melting time to obtain an objective function and an optimal value, and providing a certain reference basis for TES multi-objective optimization under the condition that the working medium is the nanofluid.

The invention provides a nanofluid fuel with metal carbide as an additive and a preparation method thereof.The nanofluid fuel comprises liquid fuel, the metal carbide and a surfactant, the metal carbide and the surfactant are evenly dispersed in the liquid fuel, the mass percent of the metal carbide is 1%-40%, the mass percent of the surfactant is 1%-20%, and the mass percent of the liquid fuel is 1%-20%. The mass percent of the surfactant is 1%-15%, and the balance is liquid fuel. By applying the technical scheme, the technical problems that in the prior art, the energy density of liquid fuel is insufficient, and the combustion heat release process of fuel is affected by surface oxidation and combustion products of traditional energy-containing nano metal particles or metal oxide particles are solved.

The invention relates to an oil field auxiliary agent, and particularly discloses a temperature-resistant salt-resistant nano fluid oil displacement agent and preparation and application thereof, the temperature-resistant salt-resistant nano fluid oil displacement agent comprises the following components by weight: 5-12 parts of modified nano SiO2 particles, 10-20 parts of a nonionic surfactant, 10-30 parts of a gemini benzoxazine surfactant, 1-5 parts of a dispersant, 10-20 parts of a mutual solvent, and 20-50 parts of water; wherein the modified nano SiO2 particles are obtained by modifying nano SiO2 particles through a macromolecular coupling agent. The nano-fluid oil-displacing agent has the beneficial effects that the recovery efficiency can be improved when the nano-fluid oil-displacing agent is used for exploiting a high-temperature and high-salt oil reservoir, and the nano-fluid oil-displacing agent is good in temperature resistance and salt resistance, small in particle size and capable of remarkably reducing the oil-water interfacial tension.

The invention belongs to the technical field of efficient heat management, and relates to a nanofluid enhanced heat exchange system based on a built-in ultrasonic device, which comprises an integrated micro-channel cooling plate 2, an embedded ultrasonic device 3, a nanofluid circulating system and an intelligent control system 5, the integrated micro-channel cooling plate 2 is attached to the surface of a heating device 1 (such as a solar cell panel), and the embedded ultrasonic device 3 is attached to the surface of the heating device 1. A groove is formed in the side, away from the heating device 1, of the integrated micro-channel cooling plate 2, the embedded ultrasonic device 3 is installed in the groove, and the nano-fluid circulating system and the embedded ultrasonic device 3 are in electric signal connection with the intelligent control system. The invention can effectively solve the industrial problems of high-temperature efficiency reduction, nanofluid agglomeration instability and the like of the solar cell panel, improve the heat dissipation efficiency and improve the conversion efficiency of the cell panel.

The invention relates to the technical field of fluid heat dissipation, in particular to a heat transfer characteristic analysis method, device and equipment of nanofluid and a medium. According to the method, a velocity calculation formula is constructed based on a power law fluid model, then the velocity calculation formula is applied to the slip length, the fluid attribute information and the pipeline attribute information to obtain the flow velocity of the nanofluid in the miniature pipeline, then the average temperature of the nanofluid in the miniature pipeline is calculated based on the flow velocity, and finally the temperature of the nanofluid in the miniature pipeline is calculated based on the average temperature. And calculating the Nusselt number of the nanofluid in the miniature pipeline. The power law fluid model can describe the non-Newtonian characteristics of the nanofluid, and the non-Newtonian characteristics are suitable for the heat transfer characteristics of the nanofluid in the miniature pipeline, so that the flow velocity, the average temperature and the Nusselt number can describe the heat transfer characteristics of the nanofluid in the miniature pipeline; therefore, the nanofluid can be applied to micro-scale cooling.

The invention discloses a low-permeability reservoir nanofluid oil displacement simulation method based on an immersed boundary method, belongs to the technical field of petroleum and natural gas extraction, is used for fluid oil displacement simulation, and comprises the steps of constructing a two-dimensional pore throat image, constructing an oil-water two-phase seepage simulation method and updating macroscopic fluid parameters. Analyzing the stress condition of the active nano-particles, constructing an active nano-particle kinematical equation, and tracking the motion trail of the active nano-particles; an interaction coupling format between active nanoparticles and fluid is constructed based on an immersed boundary method (IBM), a nanofluid oil displacement process is represented, behavior dynamic parameters of the nanoparticles under different injection conditions are analyzed, and main control factor analysis is carried out. According to the method, the inter-phase acting force is simulated through the pseudo-potential function, accurate simulation of oil displacement by water is achieved, an active nano-particle kinematics control equation is constructed, updating of the flow speed and the position of the active nano-particles is achieved, and design and use of nano-fluid in a low-permeability reservoir site are further guided.

The invention relates to the technical field of combustion testing, in particular to a testing device for studying the combustion characteristic of nanofluid fuel. The device comprises an operation table, wherein a convenient combustion adjusting mechanism and a waste gas treatment assembly are mounted on the upper surface of the operation table; the convenient combustion adjusting mechanism comprises a storage tank and a combustion chamber, a pump body is arranged between the storage tank and the combustion chamber, a connecting pipeline is connected between the storage tank and the pump body, a pressure adjusting assembly is arranged between the pump body and the combustion chamber, and an outlet of the combustion chamber is connected with a waste gas treatment assembly; a combustion component and an igniter are arranged on the top of the inner side of the combustion chamber. According to the pressure adjusting assembly, fuel flowing and gas supply can be effectively controlled, the combustion process is stable, accurate test conditions are achieved, the reliability of test results is improved, and fuel performance can be deeply analyzed conveniently.

The invention relates to a two-phase liquid cooling system based on a nanoparticle deposition boiling enhancement mechanism. The two-phase liquid cooling system comprises an external cooling unit, an immersion cooling cabinet, a cooling water distribution unit, a nanofluid distribution unit and a coolant distribution unit, the immersion cooling cabinet, the nanofluid distribution unit and the coolant distribution unit are all arranged in the cabinet area; the data center machine room is formed by connecting multiple cabinets in parallel. Compared with the prior art, through a simple and low-cost nano-particle self-assembly mode, the boiling capacity is improved, and meanwhile the improvement cost is reduced; a non-homogeneous wettability surface is prepared according to a self boiling mechanism, so that the energy utilization efficiency of the two-phase liquid cooling system is effectively improved; the deposition strength of the nanoparticles is controlled through the difference of the heat conduction materials, so that the boiling surface is selectively enhanced, the pool boiling effect is effectively improved, and the efficiency of a cooling system is improved.

The invention relates to the technical field of geothermal energy development and utilization, in particular to a horizontal well carbon dioxide fracturing-heat removal-utilization integrated method and device.The method comprises the steps that fracturing fluid in a supercritical state is injected into an injection well to fracture a geothermal reservoir to form cracks; injecting nanofluid formed by mixing fracturing fluid in a supercritical state and heat-conducting nanoparticles into the cracks of the geothermal reservoir through the injection well so as to absorb heat energy of the geothermal reservoir; and the nanofluid absorbing the heat energy of the geothermal reservoir is conveyed into a ground heat removal system through a production well, so that the heat energy generated by expansion of the nanofluid is collected. According to the embodiment of the invention, the geothermal reservoir is fractured by the fracturing fluid in the supercritical state, the permeability of the geothermal reservoir is improved, and geothermal resources can be ensured to flow and be extracted more efficiently. The heat-conducting nano-particles and the fracturing fluid in the supercritical state are combined to form the nano-fluid, so that the heat energy extraction efficiency is greatly improved, and efficient utilization of geothermal resources is achieved.

The invention discloses a high-temperature-resistant composite nanofluid scale inhibitor and a preparation method thereof, and belongs to the technical field of oilfield chemistry. The composite nano fluid scale inhibitor is prepared from modified graphene oxide nano AP-GO, a calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS, a surfactant, an inorganic salt and deionized water, the calcium-based nano modifier calcium-based polysulfonic acid contains a large amount of sulfonic acid, carboxylic acid and hydroxyl groups, has strong hydrophilicity, calcium ion tolerance and calcium ion chelating property, and has a good scale inhibition effect on calcium carbonate scale and barium sulfate scale; meanwhile, the modified graphene oxide nanoparticles have large-scale conjugated rings, a large amount of carboxylic acid and hydroxyl groups, and have synergistic interaction with calcium-based polysulfonic acid under the action of anion shielding and large steric hindrance effects, so that the high temperature resistance and scale inhibition performance of the nano scale inhibitor are further improved, a good scale inhibition effect is achieved, and the problems of oilfield water injection and fracturing flowback scaling are effectively solved; good popularization prospects are realized.

The invention relates to the technical field of micro-channel heat exchange, and particularly discloses an efficient micro-channel heat exchange method and application thereof.The efficient micro-channel heat exchange method comprises the steps that an embedded sensor system is used for monitoring the flow speed, temperature, pressure and flow data of fluid in real time, and fluid state information is obtained in real time; the fluid state information is fluid flow velocity, temperature, pressure and flow data acquired based on an embedded sensor; on the basis of real-time fluid state information, the flow velocity, flow direction and temperature of the fluid or the concentration of the nanofluid are adjusted through big data analysis and an artificial intelligence algorithm; the flow velocity, temperature, pressure and other parameters of the fluid are monitored in real time, big data analysis and an artificial intelligence algorithm are combined, the flow state of the fluid is accurately adjusted, the phenomena of uneven flow and stagnation flow are reduced, and therefore the overall heat exchange efficiency is improved. Besides, by optimizing the thermal conductivity, the hydrophilic-hydrophobic property and the surface roughness of the coating on the surface of the micro-channel and applying a nano material, the heat exchange capacity between the fluid and the wall of the micro-channel is enhanced.

The invention discloses a soft coal seam nanofluid fracturing propping material and a preparation method thereof.The soft coal seam nanofluid fracturing propping material is prepared from, by weight, 80-90% of a base material, 1-5% of a super-hydrophobic coating, 5-10% of a catalytic active component and 5-15% of a rheological enhancer, the base material is a compound of high-purity silicon dioxide nanoparticles and graphene nanosheets GNP, the particle size of the high-purity silicon dioxide nanoparticles is 50-200 nm, the super-hydrophobic coating is a fluorosilane modified layer, the thickness of the super-hydrophobic coating is 5-20 nm, and the invention relates to the technical field of coal bed gas exploitation. According to the soft coal seam nanofluid fracturing propping material and the preparation method thereof, the surface of the material is provided with a super-hydrophobic coating, friction force with a coal matrix is reduced, high embedding resistance is achieved, the flow conductivity is specifically enhanced, an extra flow channel is provided through a porous nanostructure, the fracturing fluid permeability is improved, and meanwhile gas desorption can be cooperated; catalytic active sites are introduced to the surface of the material to promote adsorption and diffusion of methane molecules.

Disclosed are a CO2 gas-soluble silicon nanofluid and a preparation method therefor. The method includes: taking nano-silica and grafting a silane coupling agent to obtain modified nano-silica; taking methylsiloxane, fluorosilicone, aminosiloxane and an end-capping agent, and performing polymerization under the action of a catalyst to obtain a functionalized network siloxane; and taking the modified nano-silica and the functionalized network siloxane, uniformly mixing, then heating for a Michael addition reaction, and obtaining the gas-soluble silicon nanofluid after the reaction is completed. The gas-soluble silicon nanofluid microscopically forms a network structure with modified nano-silica as a cross-linking point and polysiloxane as a chain; macroscopically, the effect of viscosity increase of the supercritical carbon dioxide is significant, and the dissolving pressure is low. The interfacial tension and the miscibility pressure between the crude oil and CO2 are significantly reduced.

The invention relates to the technical field of nanofluid enhanced heat transfer simulation, in particular to a molecular dynamics-based mixed nanofluid heat transfer characteristic analysis method, which comprises the following steps of: constructing a molecular model comprising copper, graphene nanoparticles and an ionic liquid / water mixed base solution, and calculating the heat transfer characteristic of the mixed nanofluid through a distribution potential function and a periodic boundary condition; and performing energy minimization and molecular dynamic relaxation to achieve thermodynamic equilibrium. A steady-state temperature gradient is established based on the unbalanced molecular dynamics principle, and the thermal conductivity is calculated according to the Fourier law. Microcosmic parameters such as a radial distribution function, mean square displacement and the number of hydrogen bonds are synchronously analyzed, and a coupling mechanism of interaction and heat transfer performance of the nano-particle-base fluid interface is disclosed. According to the method, the heat transfer characteristic of the mixed nanofluid can be clarified on the molecular scale, and an efficient and reliable analysis means is provided for nanofluid screening and design in application of a solar heat collector, a heat management system and the like.

The invention provides a method for determining a nanofluid oil displacement effect of a low-permeability reservoir, and relates to the technical field of oil exploitation. The method comprises the following steps: providing a core of a low-permeability reservoir, and measuring the particle size of nanoparticles in a target nanofluid; performing high-pressure mercury injection test and nuclear magnetic resonance measurement on the rock core to respectively obtain a rock core pore throat radius-distribution frequency relation curve and a first T2 image, and performing benchmarking on the two images to obtain a pore throat radius-relaxation time relation curve; carrying out displacement experiments (oil displacement, first water displacement, nanofluid displacement and second water displacement) on the rock core, and carrying out nuclear magnetic resonance measurement to obtain T2 images; and observing or calculating the area enclosed by the curve and the relaxation time in each image, and combining with a pore throat radius-relaxation time relation curve to obtain the oil displacement effect of the nanofluid on different pores of the oil reservoir. The oil displacement effect of the nanometer system is determined according to the characteristic parameters of the reservoir core before and after the nanometer fluid is injected, and the method has important guiding significance for formulating a scheme for improving the recovery effect of the low-permeability oil reservoir.

The invention discloses an oil-displacing agent based on zirconium oxide nanosheets and a preparation method of the oil-displacing agent. The oil displacement agent comprises the following components in parts by mass: 0.2-1 part of zirconium oxide nanosheets, 10-30 parts of a surfactant and 5000-10000 parts of water, the size range of the zirconium oxide nanosheet is 200 to 300 nm. The two-dimensional zirconium oxide nanosheet is prepared by utilizing a green substitute solvent-ionic liquid assisted alcohol solvothermal method, the synthesis method is simple, convenient, effective and green, and the size of the product is controllable. The zirconium oxide material has the characteristic of changing rock wettability, and can be used as a metal oxide nano material to improve the viscosity of the prepared nanofluid, reduce the fluidity ratio, generate structural separation pressure on the interface of crude oil and reservoir rock and realize efficient stripping of retained crude oil, thereby greatly improving the recovery efficiency.

The invention discloses a nanofluid mixed matrix membrane as well as a preparation method and application thereof, and belongs to the field of gas separation. The nanofluid mixed matrix membrane comprises a polymer matrix and a nanofluid filler, the nanofluid filler is of a three-dimensional layered structure, a core layer is a porous material layer, a secondary outer layer is a coupling agent connecting layer, and an outermost layer is an organic matter coronal layer containing a CO2-philic group. The coronal layer improves the compatibility of the porous material and the polymer matrix and increases the CO2 affinity of the mixed matrix membrane, not only increases the diffusivity of the mixed matrix membrane, but also increases the CO2 solubility, and due to the unique connection mode between the porous core and the coronal layer, the thermal stability of the porous core and the coronal layer is also enhanced. Therefore, the prepared novel efficient mixed matrix membrane has good gas separation performance and thermal stability and is especially suitable for CO2 separation, and CO2 / H2 of the product breaks through the Robeson upper limit in 2008.

The present invention provides functionalized molybdenum disulfide nanosheets and a preparation method and application thereof. The preparation method comprises the following steps: mixing a solvent, 1 part by weight of thioctic acid, and 5 to 10 parts by weight of a first compound for 2 to 4 hours to obtain a mixture; adding 0.05 to 0.1 parts by weight of 1-hydroxybenzotriazole to the mixture, mixing for 24 to 48 hours, and drying to obtain an intermediate product; and ultrasonically treating or heat-treating the raw material-solution system to obtain the functionalized nanosheets, wherein the raw material-solution system comprises 5 to 10 parts by weight of molybdenum disulfide nanosheets, 1 part by weight of the intermediate product, and brine; and the first compound comprises an oxirane group and an alkylamine chain, wherein the alkylamine chain has 12 to 18 carbon atoms and the oxirane group has 2 to 15 carbon atoms. A nanofluid prepared from the functionalized molybdenum disulfide nanosheets can reduce oil / water interfacial tension, has good stability, significantly improves the recovery rate of low-permeability oil reservoirs, and reduces costs.

The invention relates to the technical field of micro-nano electronic devices, in particular to a nanofluid memristor prepared by puncturing a PDMS film and a mechanical-electric coupling regulation and control system and method of the nanofluid memristor. The memristor is composed of a silicon substrate with a window and a PDMS thin film covering the silicon substrate, a three-degree-of-freedom probe station is used for driving a tungsten probe to conduct nanoscale puncture on the PDMS thin film under an optical microscope, and a pore channel with the self-constriction / reversible closing characteristic is formed; after the needle is removed, the hole channel is in a near-closed or sub-nanometer equivalent hole diameter state, by applying controllable pressure to the closed liquid chamber and superposing bias voltage, sudden change / gradual change dual-mode regulation and control of the hole diameter and non-volatile hysteresis conductance switching are achieved, and the switch ratio of the device can reach 108. According to the method, FIB is not needed in hole forming, the process is simple and convenient, the cost is low, high-contrast and programmable nanofluid memristive behaviors are achieved through the structural design of the window orientation and the clamping direction, pressure rate programming and a pressure removal maintaining / negative pressure reset strategy, and the method is suitable for the fields of single molecule detection, ion circuit storage and the like.

Provided are a wafer cleaning method capable of uniformly cleaning an entire area of a wafer, and a wafer cleaning apparatus to which the method is applied. The method includes positioning a cleaning tool to face a surface of the wafer requiring cleaning; supplying a cleaning liquid containing ions to an area between the wafer and the cleaning tool; adjusting a spacing between a surface of the wafer and the cleaning tool for a viscosity of the cleaning liquid therebetween to be controlled by an electric field; and relatively rotating the wafer from the cleaning tool while the electric field being applied to at least a portion of the cleaning liquid, thereby cleaning the surface of the wafer with the cleaning liquid.

This application discloses a nanofluid, its preparation method, and its applications. The nanofluid comprises, by mass fraction: 0.01% to 0.7% modified nanoparticles, 1% to 4% surfactant, 0.2% to 0.6% polymer, and 0.01% to 0.2% short-chain alkanes, with the balance being water. The nanofluid provided in this application, through the synergistic effect between specific components, can significantly improve C / W foam stability and enhance oil recovery. Foam displacement agents prepared using this nanofluid can improve permeability and asphaltene content after displacement, exhibiting good overall performance.

The invention provides a transparent restraint layer suitable for laser shock and a laser shock forming method and device of a metal plate, belongs to the technical field of metal plate laser processing, and aims to solve the technical problem of failure of the restraint layer in a low-temperature environment. The forming method comprises the steps that an absorption layer and a transparent restraint layer are sequentially laid on the surface of a to-be-impacted workpiece, and the transparent restraint layer sequentially comprises a polyurea-polyurethane elastomer layer, a nanofluid layer and a hydrogel layer in the direction close to the to-be-impacted workpiece to the direction away from the to-be-impacted workpiece; a single-laser-head or multi-laser-head array is adopted to implement pulse impact, and a temperature-stress-displacement multi-physical-field closed loop is constructed through displacement sensing, temperature sensing and ultrasonic stress sensing; and the industrial controller operates a model prediction control algorithm to perform linkage optimization on the laser energy density E, the scanning speed v and the hydrogel layer volume flow q. Compared with an existing double-layer constraint and double-feedback scheme, the method has remarkable technical progress in the aspects of low-temperature stability, array consistency and forming consistency.

A kind of solid-liquid two-phase nanofluid cooling fluid optimization method for machine tool spindle dynamic cooling, first carry out the sensitivity / correlation analysis of parameter variable, find out the nanofluid parameter that is strongly related to convective heat transfer characteristics;Then describe the percolation structure of nanoparticle aggregation, based on thermal conductivity model and effective viscosity model into finite element simulation;Then analyze and determine the key parameters of nanofluid in spindle cooling, qualitative selection of the optimization combination of key parameters;According to the "two-step method", nanofluid is prepared, and convective heat transfer experiment is carried out for nanofluid, and the experimental results of nanofluid are compared transversely, and the nanofluid with maximum average convective heat transfer coefficient is selected quantitatively;The present application greatly improves the convective heat transfer rate of the cooling fluid in the machine tool spindle, makes the precision machine tool spindle thermal error in high-speed machining long-term stable, and then eliminates the influence of spindle thermal error on machining precision of machine tool through tool.

The invention discloses a design method of a magnetic field driven nano-magnetofluid directional transportation micro-groove texture and the micro-groove texture, and directional transportation is realized by designing a conical micro-groove texture and matching with an external magnetic field driven nano-magnetofluid. And recording the contact point of the nanofluid and the micro-groove texture and the time from the middle end point of the nanofluid to the small end of the channel, designing a calculation method for measuring the overall speed of the liquid drop, optimizing the micro-texture taper angle by taking the fastest overall speed of the liquid drop as a target, and calculating the non-dimensional energy of the liquid drop to obtain the micro-groove texture. The microtexture small end diameter is optimized with the maximum dimensionless energy difference as the target; and calculating the magnetic field force borne by the liquid drop, and optimizing the magnetic flux density by taking the maximum magnetic field force as a target. According to the design method, the optimal micro-texture structure can be optimized, and the fastest rate transportation of liquid is realized.