107 results about "Nucleation growth" patented technology

This invention relates to an in-situ detection system for a rotating microliquid film reactor (MFR) for monitoring the nucleation behavior of nanomaterials. The reactor comprises a rotor and a stator, with a stator base angle of 70-85°, a rotational speed of 500-5000 rpm, and a slit width of 10-500 μm to ensure that fluid passing through the slit does not undergo backmixing and to create a strong shear field. A micro-negative pressure sampler is fabricated to capture nucleating particles within the high-speed shear field and bring them into the visible observation area. A high-speed camera and microscope objective are connected in situ, thereby acquiring instantaneous images of the nucleation process at the nanoscale and capturing the transient evolution behavior of crystal nuclei. The construction of this rotating MFR in-situ detection system solves the problems of poor micro-mixing effects and uncontrollable nucleation and growth in traditional stirred tank reactors, leading to poor quality in large-scale preparations, and the inability to observe phase transitions and instantaneous nucleation processes in a closed reactor. The obtained hydrotalcite nucleation results enrich non-classical nucleation theories and provide guidance for the large-scale preparation of nanomaterials.

The present invention provides a method for preparing high-stability two-dimensional black phosphorus. First, a phosphorus source and an iodine source are introduced into a reaction system for preliminary preheating and activation. After being fully activated in the raw material area of ​​the reaction system, they are slowly transferred to the crystal growth area of ​​the reaction system. The phosphorus source and the transport agent flow through the liquid to the catalyst and are fully converted in the intermediate formation area. The converted intermediate slowly moves to the crystal nucleation growth area to begin crystal nucleation and growth. After further sufficient reaction, the crystal nucleation growth point continues to extend and grow, and finally the black phosphorus crystal slowly nucleates and grows in blocks. After the crystal growth is completely cooled to room temperature, the unconverted raw materials are reused until they are finally converted into black phosphorus crystals and tail gas. The tail gas is absorbed and converted into other by-products. The use of high-temperature and high-pressure resistant pipelines can achieve efficient transportation of gaseous phosphorus, thereby extending the growth time of black phosphorus crystals and improving the growth efficiency of black phosphorus crystals.

The invention provides a positive electrode material precursor and a preparation method and application thereof. The preparation method comprises the following steps: a first stage: introducing a ternary metal salt solution, a complexing agent and a precipitator into a first reaction kettle, and carrying out nucleation growth to obtain a core solution; in the second stage, the core solution is transferred into a second reaction kettle, and a ternary metal salt solution, a complexing agent and a precipitator are introduced for a growth reaction until the particles grow to the target particle size in the second stage; and a third stage: keeping the introduction of each raw material solution in the second stage, and introducing the doped metal salt solution to continue the growth reaction until the growth particle size of the particles reaches the target particle size in the third stage, thereby obtaining the positive electrode material precursor. According to the invention, a reaction container transfer means is utilized, so that the doping elements are intensively doped into the shell layer of the particles in the coprecipitation process, the maximized doping effect is realized in the most efficient mode and at the lowest cost, and the electrochemical performance of the positive electrode material is remarkably improved.

The invention provides a cobalt tungstate and bismuth vanadate photocatalytic material as well as a preparation method and application thereof, and belongs to the technical field of material synthesis and photocatalytic application. In the presence of monoclinic-phase decahedron BiVO4, CoWO4 nanoparticles grow in situ on an electron-rich (010) crystal face of the CoWO4 nanoparticles through a hydrothermal reaction, and the cobalt tungstate and bismuth vanadate photocatalytic material is obtained. According to the cobalt tungstate and bismuth vanadate photocatalytic material, a simple hydrothermal method is adopted, in the synthesis process, a CoWO4 precursor is guided by electrostatic interaction, preferentially adsorbed and subjected to nucleation growth on the (010) crystal face of BiVO4, a compact chemical bonding interface is constructed through selective growth, the charge migration distance is effectively shortened, and the photocatalytic performance of the material is improved. The interface charge transfer resistance is reduced to the greatest extent, and the formed binary photocatalyst has excellent effects on photocatalytic hydrogen evolution and tetracycline degradation.

The invention discloses a novel antifreeze polypeptide with a clear structure and excellent performance and a protection method of cryopreserved cells. The core structure of the polypeptide is formed by covalently connecting two functional modules, the N end is a unit with ice crystal binding performance, the C end is a super-hydrophilic unit, and the two functional modules are bridged through a flexible linker. Experimental verification shows that the synthetic polypeptide shows excellent anti-freezing activity, can significantly inhibit nucleation, growth and recrystallization processes of ice crystals, and has particularly outstanding ice recrystallization inhibition activity. The novel antifreeze polypeptide shows excellent biocompatibility, and is suitable for low-temperature cryopreservation of cells sensitive to freezing damage and other living microbial preparations. Results show that the polypeptide can greatly improve the freeze-drying survival rate of cells and the activity of the cells after recovery, is non-toxic to the cells, and shows the potential of replacing a traditional cryoprotectant. Therefore, the method has wide application prospects in food industry, biological medicine, agricultural breeding and low-temperature preservation technologies of biological sample libraries.

The application relates to the technical field of catalysts, and discloses a nano magnesium oxide material and a preparation method and application thereof. The nano magnesium oxide material has a porous structure, wherein the particle size of the nano magnesium oxide is 20-200 nm; and the pore size of the porous structure is 5-45 nm. The classical nucleation growth process of the magnesium oxide is directionally adjusted in a weak alkaline nucleation system, and then the nano magnesium oxide with a controllable grain size distribution is obtained. The nano magnesium oxide material has good catalytic activity in the synthesis of propylene carbonate from CO2 and an epoxide under the conditions of no solvent and no auxiliary agent, and the catalyst is not deactivated after multiple uses, and has good stability.

The invention discloses a magnesium carbonate crystal prepared based on hexamethylenetetramine and a preparation method thereof, and belongs to the technical field of magnesium carbonate materials. The preparation method comprises the following steps: dissolving urea and magnesium chloride, adding hexamethylenetetramine, oscillating in water bath ultrasonic to fully react, then transferring the reaction system into a hydrothermal reaction kettle to perform hydrothermal reaction, and washing and drying a reactant to obtain magnesium carbonate crystals. According to the invention, magnesium chloride and urea are taken as raw materials, hexamethylenetetramine is taken as an additive, the nucleation-growth process is directionally regulated by the hexamethylenetetramine additive, and an optimized reaction process is adopted, so that the magnesium carbonate crystal with high purity, good crystallinity and an excellent pore structure is successfully synthesized; the prepared magnesium carbonate crystal has an optimized porous structure. According to the structure, the mass transfer efficiency is effectively improved, diffusion and transmission of substances in the material are facilitated, and the preparation method is simple and has wide application potential.

The application provides an inorganic doped electrochromic fabric and a preparation method thereof. The flexible conductive fabric is first treated with an ammonium sulfate solution for hydrophilic treatment to obtain a pretreated fabric; then a tungsten chloride anhydrous ethanol solution is prepared, and molybdenum pentachloride powder is added to prepare a precursor solution; finally, the pretreated fabric is placed in the precursor solution for high-temperature reaction, and the inorganic doped electrochromic fabric is obtained after the reaction is completed. The flexible conductive fabric is treated with the ammonium sulfate solution, functional treatment is realized, and the surface activity is improved, so that the chemical bonding between the fabric and the electrochromic film is promoted; the molybdenum pentachloride is selected as the precursor, which provides a site for the nucleation and growth of WO3 on the surface of the fabric, so that a stable WO3 and MoO3 composite film is formed, the film serves as an electrochromic layer, the fabric has excellent electrical, optical and mechanical properties, has a fast optical response time and a high coloring efficiency, and can be applied to the fields of smart clothes and implantable display.

The application discloses preparation of one-dimensional rare earth metal-organic framework, one-dimensional rare earth metal-organic framework loaded transition metal-organic framework material and preparation and application, relates to the technical field of one-dimensional nanowire RE-MOF material preparation and double-MOF composite core-shell structure preparation, and a preparation method comprises the following steps: synthesizing a series of RE-MOF precursor one-dimensional nanowires by a solvent thermal method; at room temperature, in a methanol solvent system, PVP is used as an inducer to promote Co 2+ Deposition and enrichment on the surface of the RE-MOF, and then nucleation and growth of a uniform TM-MOF shell layer are formed by the coordination of 2-methyl imidazole and Co 2+ , thereby obtaining a core-shell structure one-dimensional nanowire Co-MOF@RE-MOF material. Finally, the prepared series of core-shell structure one-dimensional nanowire materials are subjected to calcination treatment in an argon atmosphere, and a multi-component composite wave-absorbing material with good wave-absorbing performance is obtained.

This invention discloses a retarder for magnesium silicate cementitious materials and its preparation and application methods, belonging to the field of green building materials technology. The retarder of this invention is composed of sodium hexametaphosphate, citric acid, and tartaric acid in a mass ratio of (1-3):(2-4):(0.5-2). The retarder of this invention forms a three-level gradient synergistic retarding effect by using sodium hexametaphosphate to inhibit the rapid dissolution of active magnesium oxide, citric acid to chelate and regulate the magnesium ion concentration in the liquid phase, and tartaric acid to inhibit the nucleation and growth of hydration products, covering the entire hydration process of magnesium silicate cementitious materials. This invention also discloses the preparation and application methods of this retarder. Compared with existing technologies, the retarder of this invention can significantly extend the setting time of magnesium silicate cementitious materials while maximizing the preservation of their mechanical properties and improving slurry fluidity. Furthermore, the raw materials are widely available, the preparation process is simple, and the cost is controllable, showing good prospects for industrial application.

The invention relates to a method for one-step synthesis of high-quality stannous oxide through intermittent ultrasonic reinforcement, and belongs to the technical field of semiconductor material preparation. The preparation method comprises the following steps: dropwise adding a sodium hydroxide aqueous solution into a stannous chloride aqueous solution at room temperature under a stirring condition until the pH value is 12.5-13.5 to form a mixed solution system; applying intermittent ultrasonic waves to the mixed solution system for intermittent ultrasonic treatment to induce direct nucleation and growth of stannous oxide and synchronous removal of chlorine impurities, carrying out solid-liquid separation, and drying the solid to obtain the low-chlorine fine-particle-size stannous oxide. According to the method, through the work-stop periodic effect of intermittent ultrasound, dynamic conditions are provided for diffusion and desorption of chloride ions while nucleation and growth regulation are promoted through cavitation, cooperative regulation of particle size refinement and deep dechlorination of stannous oxide is achieved, a high-temperature step or repeated washing is not needed, the process is simple and efficient, the conditions are mild, and the method is suitable for industrial production. And controllable preparation of the high-performance stannous oxide material can be realized.

The utility model discloses a gradient regulation type nanometer active silicon particle size synthesis reaction device, which relates to the technical field of nanometer active silicon particle size synthesis reaction devices and comprises an active silicon reaction kettle, a cavity is arranged in the active silicon reaction kettle, and an electric heating plate is sleeved in the cavity. The inner wall of the active silicon reaction kettle is fixedly connected with an ultrasonic assembly. According to the gradient regulation and control type nano active silicon particle size synthesis reaction device, through cooperative coupling of the electric heating plate and the ultrasonic assembly, the ultrasonic generator drives the multiple ultrasonic transducers which are symmetrically distributed to form a uniform cavitation field, and meanwhile the electric heating plate dynamically adjusts a temperature field based on a control panel instruction; space-time matching optimization of a temperature-cavitation dual-energy field is achieved, reaction nonuniformity caused by energy field separation of traditional equipment is effectively overcome, ultrasonic hot spots in the reaction kettle are eliminated through ultrasonic transducers which are arranged on a connecting rod in an axial symmetry mode, nano silicon particle nucleation growth kinetics are controllable, and the particle size standard deviation is reduced.

The embodiment of the application relates to a method for preparing perovskite quantum dots assisted by supercritical carbon dioxide, and belongs to the technical field of perovskite quantum dots. The method solves the problems of complex process of hot injection method, large amount of anti-solvent required by ligand assisted precipitation method and difficult size control. The specific steps include: 1) dissolving lead halide and ligand 1 in polar solvent 1 to form precursor solution A; 2) dissolving cesium halide and ligand 2 in polar solvent 2 to form solution B; 3) premixing solution A and supercritical carbon dioxide to be homogeneous; 4) adding anti-solvent 3 into the reaction kettle and introducing the homogeneous phase of solution A and supercritical carbon dioxide; 5) rapidly injecting solution B for reaction, and releasing pressure after crystal nucleation and growth; 6) collecting and purifying the product. The method is green and efficient, and the prepared perovskite quantum dots are suitable for the fields of optoelectronic devices, display and lighting, etc.

This invention discloses a one-dimensional WS2 / WSe2 heterojunction material, its preparation method, and its applications, belonging to the field of nanomaterials technology. The one-dimensional WS2 / WSe2 heterojunction material is a one-dimensional structural material composed of alternating WS2 nanoribbons and WSe2 nanoribbons arranged along its width direction. Furthermore, this invention proposes a method for preparing the one-dimensional WS2 / WSe2 heterojunction material, comprising: arranging a WS2 source and a WSe2 source separately in a reaction apparatus, and placing a growth substrate loaded with salt halides in the nucleation growth region; heating to the growth temperature under a protective atmosphere to allow the WS2 source and WSe2 source to react sequentially; and obtaining the one-dimensional WS2 / WSe2 heterojunction material through catalytic induction of the salt halide by sequentially switching the effective supply of the WS2 source and WSe2 source. The one-dimensional WS2 / WSe2 heterojunction material proposed in this invention exhibits high crystallinity and a clear heterojunction interface.

According to an embodiment of the present application, a method for forming a film with area selectivity includes: a step of supplying a nucleation growth inhibitor into a chamber in which a substrate is placed, so that the nucleation growth inhibitor is adsorbed to a non-growth area of the substrate; a step of purging the inside of the chamber; a step of supplying a precursor into the chamber, so that the precursor is adsorbed to a growth area of the substrate; a step of purging the inside of the chamber; and a step of supplying a reaction material into the chamber, so that the reaction material reacts with the adsorbed precursor to form a film.

The invention relates to the technical field of electrocatalytic materials, in particular to a SnSe piezoelectric catalyst and a preparation method and application thereof. The preparation method comprises the following steps: dispersing selenium powder in deionized water, adding NaBH4 powder to obtain a selenium source precursor solution, dispersing sodium ascorbate in deionized water, adding anhydrous SnCl2 powder to obtain a tin source precursor solution, and adding the selenium source precursor solution into the tin source precursor solution to obtain a mixed solution; the pH value of the mixed solution is adjusted to 2-7, then the mixed solution is subjected to a hydrothermal reaction, and the SnSe piezoelectric catalyst is obtained through filtering and drying in sequence. In a one-step hydrothermal system, through coordinated regulation and control of pH and hydrothermal temperature, coordinated regulation of the SnSe material in the aspects of nucleation, growth, valence evolution and defect structure is realized, a novel piezoelectric catalytic material with a mixed valence structure and nanorod morphology is successfully constructed, the piezoelectric polarization capability, the carrier separation efficiency and the ROS generation capability of the material are remarkably enhanced, and the preparation method is simple and easy to implement. And excellent organic pollutant degradation performance is obtained.

The invention discloses a perovskite nanocrystal with low lead loss and high fluorescence quantum efficiency and a preparation method thereof, which can effectively reduce environmental pollution caused by discharge of lead element, and the preparation method comprises the following steps: placing A2CO3 or A (CH3COOH), lead acetate and metal salt in a container, adding organic acid and a non-coordination solvent to construct a reaction environment, after high temperature dissolution, injecting a halogen reaction source, and after the reaction is completed, adding an organic acid and a non-coordination solvent to prepare a perovskite nanocrystal with low lead loss and high fluorescence quantum efficiency. Performing reaction to synthesize coarse nanocrystals, performing surface reconstruction by using a quaternary ammonium salt solution to promote separation and purification, and cleaning to obtain a clear and transparent quantum dot solution; on the basis of an original ternary synthesis method, nucleation growth of the nanocrystals is achieved by introducing non-toxic metal elements, efficient conversion from lead element feeding to a product is promoted, and therefore the strong emission characteristic and stability of the nanocrystals are guaranteed while lead source emission and environmental pollution in the synthesis process are reduced.

The invention discloses a method for researching an MOF (Metal Organic Framework) synthesis process by utilizing a low-field nuclear magnetic imaging device, and belongs to the technical field of material synthesis process analysis. The method comprises the following steps: firstly, preparing a metal source solution and an organic ligand solution; one of the solutions is selected for low-field nuclear magnetic resonance relaxation time measurement, and imaging sequence parameters are optimized; mixing the two solutions, and immediately putting the mixed solution into a low-field nuclear magnetic imaging device; and carrying out continuous relaxation time weighted imaging and layered relaxation time measurement on the reaction process by using the optimized imaging sequence. The lossless, in-situ, visual and quantitative monitoring of the metal-organic framework material in the nucleation, growth and sedimentation process is realized by analyzing the change of image signal intensity in time and space and the change trend of relaxation time (such as T2 value) of different liquid layers along with time. According to the method, required equipment is simple, operation is convenient and fast, and an innovative research means is provided for deeply understanding the MOF synthesis mechanism and optimizing the synthesis process.

The present application relates to the field of micro-nano fluid, in particular to a cavitation bubble periodic generation method based on laser plasmon effect. The method uses continuous wave laser in plasmon resonance wave band, which is focused by a microscope objective and irradiated to the surface of a fused quartz sample covered with noble metal nanoparticles placed in liquid water environment; the laser spot is positioned near the solid object on the sample surface in advance, and the laser is turned on, the laser with power exceeding the threshold value will induce micron-scale cavitation bubble nucleation, growth and collapse at the laser spot position; the solid object near the laser spot as the flow field boundary will make the bubble produce movement towards the solid object during the collapse process, so that the bubble nucleus after collapse is pinned out of the laser spot area; the laser spot area is covered by liquid again, and under the condition of continuous laser energy input, cavitation bubble nucleation can be induced again at the laser spot position, thus forming a high-frequency, periodic cavitation bubble nucleation, growth and collapse process. The operation of the present application to realize the periodic generation of cavitation bubbles is very simple and easy to realize, can produce strong disturbance to the local fluid, and can realize the control of the generation frequency, size, periodic generation area range size of cavitation bubbles.

The invention discloses a preparation method for synthesizing a high-performance Prussian blue analogue under the assistance of a chelating agent and application of the high-performance Prussian blue analogue. The chelating agent is firstly coordinated with Co < 2 + >, slowly released into a reaction system and gradually subjected to iteration nucleation growth with [Fe (CN) 6] < 4->, and the high-crystallization and low-defect Prussian blue analogue is constructed. Through oriented adhesion growth and defect induction twinning of nanocubes, the particle size of the Prussian blue positive electrode material gradually nucleates and grows to about 1 [mu] m, and when the Prussian blue positive electrode material is applied to a sodium ion battery, the sodium ion diffusion rate is high, and the sodium storage capacity and the rate capability are improved. Moreover, the preparation method for preparing the Prussian blue positive electrode material is high in yield, and industrial mass production of the Prussian blue positive electrode material is facilitated. The preparation method is simple, the process is easy to control, the period is short, and the reversible specific capacity of the obtained material under the current density of 100 mA g <-1 > reaches 134.91 mAh g <-1 >; and the capacity retention ratio still reaches 70.09% even if the capacitor is circulated for 500 circles under the current density of 170 mA g <-1 >.

The application discloses an anti-radiation ferroelectric neural device and a preparation method and brain-like application thereof, and relates to the technical field of semiconductor devices.The multifunctional anti-radiation ferroelectric neural device structure is sequentially provided with a top electrode, a dielectric layer, a ferroelectric layer and a bottom electrode from top to bottom.The microphysical essence of realizing the functional characteristics of a conventional ferroelectric brain-like device is ferroelectric domain nucleation growth or continuous domain wall motion, and such gradual quasi-linear ferroelectric domain motion can only be used to simulate synaptic plasticity, which causes problems such as single function and low integration of the ferroelectric brain-like device.The application utilizes the ripple wave motion of patterned ferroelectric domains and the linking effect of conductive domain walls between adjacent patterned ferroelectric domain structures, adjusts the ripple wave motion of ferroelectric domains and charge dynamics characteristics through the dielectric layer containing nano-conductive columns, so that the simulation of various neural behaviors is realized, and more importantly, the application has strong anti-radiation capability.

The present application belongs to the technical field of colloidal semiconductor nanomaterial preparation, and aims at the problems of harsh reaction conditions, complex process system, difficult to balance component regulation and surface structure, and large-scale preparation difficulty in the preparation of existing Ag(In,Ga)S2 quantum dots, and proposes an Ag(In,Ga)S2 quantum dot room temperature step-by-step preparation method based on Ag2S template and application, through the three-step synthesis path design of first synthesizing Ag2S template, then sequentially completing AgInS2 quantum dot intermediate formation and Ga element introduction, the formation of multi-component quantum dots can be changed from complex one-step nucleation and growth process to gradual conversion process, which is conducive to improving the controllability of the reaction process and reducing the component imbalance and side reaction risk brought by the synchronous reaction of multiple metal ions; and the preparation of Ag(In,Ga)S2 quantum dots can be completed at room temperature without the complex process of high-temperature injection and long-time heating reaction.

The application discloses a method for regulating the size and crystal form of calcium carbonate particles by using charged micro-nano bubbles, and belongs to the technical field of calcium carbonate preparation. The method comprises the following steps: introducing carbon dioxide into a calcium-containing slurry or solution in the form of micro-nano bubbles through a micro-nano bubble aeration head for reaction, and applying a high-voltage direct current electric field to the micro-nano bubbles to prepare calcium carbonate particles. In the application, the carbon dioxide is introduced into the reaction system in the form of charged micro-nano bubbles through the micro-nano bubble aeration head connected with the high-voltage direct current electric field, the high-voltage direct current electric field is used to enhance the charging property and charge amount of the micro-nano bubbles, the secondary crushing of the micro-nano bubbles is induced, the bubbles with the same charging property are difficult to coalesce, and the uniform nucleation and growth of calcium carbonate are promoted; meanwhile, the micro-nano bubbles with high charge amount have higher stability in the liquid phase system, the charged bubbles can be adsorbed on the crystal surface in the calcium carbonate crystallization process, the agglomeration of the calcium carbonate particles is inhibited, and thus the regulation of the size and crystal form of the calcium carbonate particles is realized.

The invention belongs to the technical field of hydrogen storage material preparation, and provides an in-situ synthesized MOFs hydrogen storage material preparation method and a hydrogen storage material.The preparation method comprises the steps that ZrCl4 and HCl of a certain mass are mixed and stirred at the room temperature for a first set duration at the preset rotating speed; adding a solvent and a ligand into the stirred ZrCl4 and HCl mixed solution, and stirring for a second set time at a preset rotating speed; and putting the mixed solution added with the solvent and the ligand into a polytetrafluoroethylene reaction bottle for heating reaction to obtain the MOFs hydrogen storage material. In UiO-67 synthesis, HCl and ZrCl4 are added in advance to be mixed, so that the ZrCl4 is instantly subjected to Cl <->-assisted pre-hydrolysis at room temperature, metal clusters are generated, a metal framework is locked, reversible Cl <-> is used for occupying sites, and Cl <-> and long-chain 4, 4-diphenyldicarboxylic acid are subjected to precise exchange crystallization subsequently, and the problems of lattice defects and large specific surface area batch difference caused by different nucleation growth rates are thoroughly eliminated; meanwhile, the strong acid environment inhibits Zr < 4 + > hydrolysis precipitation, the single-kettle yield is doubled, and the stability and hydrogen storage performance of the material are guaranteed.

The invention discloses a lanthanum-doped high-stability ordered platinum alloy fuel cell cathode catalyst and a preparation method thereof, and belongs to the technical field of cell cathode catalysts. Atomic-scale dispersion of lanthanide elements on the porous carbon substrate is achieved through a metal-organic framework derivation strategy, abundant anchoring points are provided for nucleation growth of the platinum-based ordered alloy, and the strong interaction between the platinum-based alloy and lanthanum is ensured. Lanthanum is doped into platinum-based alloy crystal lattices through a high-temperature annealing method in a reducing atmosphere, the strong bonding effect of lanthanum and platinum is achieved, meanwhile, agglomeration of platinum-based nano-particles is restrained through the anchoring effect of lanthanum in a carrier and the confinement effect of the carrier, the formed ordered platinum-based alloy nano-particles are small in particle size, and the high platinum utilization rate is guaranteed. The preparation method is simple, low in cost and good in reproducibility, and compared with an existing commercial catalyst, the prepared lanthanum-doped platinum-based ordered alloy fuel cell cathode catalyst is lower in platinum dosage, higher in catalytic activity and better in stability.

This invention belongs to the field of membrane separation technology and discloses an ultrathin composite membrane with an interpenetrating network framework structure, its preparation method, and its application. The preparation method includes: pouring a zirconium metal solution onto the surface of a PSf base membrane, allowing metal ions to adsorb onto the PSf membrane surface; then immersing the other side of the PSf membrane in a ligand solution of 2-aminoterephthalic acid and triethylamine for a coordination reaction; after the reaction is complete, removing the membrane and placing it under suitable temperature and humidity conditions; as the organic solvent and triethylamine molecules on the membrane surface volatilize, the metal ions and organic ligands on the membrane surface complete heterogeneous nucleation and growth, forming a pure MOF membrane; finally, based on the amino group carried by the selected UiO-66-NH2, immersing an organic monomer solution onto the surface of the prepared MOF membrane, allowing interfacial polymerization reactions to occur on the MOF membrane surface and within the crystallites, thereby obtaining an ultrathin composite membrane with an interpenetrating network framework structure, which can be applied in the fields of CH4 / N2 separation and dye / salt separation.

The invention provides a boiling heat transfer experimental device for microbubble precise observation, which comprises an observation cavity for containing a boiling working medium for boiling heat transfer; the heating assembly is configured on the observation cavity and used for generating heat and regulating and controlling heat flow; the heating assembly comprises an extension part extending into the observation cavity, and the extension part is configured to be used for bearing and fixing an experimental sample and enabling the experimental sample to be immersed below the liquid level of a boiling working medium in the observation cavity; and a high-speed camera system with a lens facing the observation cavity and used for shooting the nucleation, growth and separation process of boiling bubbles on the surface of the experimental sample in the observation cavity. The boiling heat transfer experimental device can realize visualization of near-wall boiling microbubbles, and is simple in overall structure and convenient to operate.

The invention belongs to the related technical field of laser processing, and discloses a method and a device for realizing directional high-yield devitrification in glass, and the method comprises the following steps: applying femtosecond laser pulse to the interior of the glass, modifying agent ions and forming agent ions in the glass are directionally migrated, and an ion component gradient distribution area is formed due to different migration speeds; controlling the femtosecond laser pulse to enable the path of the ion component gradient distribution area in the preset direction to be shortest or enable the ion concentration difference of the boundary of the ion component gradient distribution area in the preset direction to be maximum; and carrying out heat treatment on the glass, so that the ions in gradient distribution are further diffused, the ion diffusion flux in the preset direction is maximum, and in a laser irradiation area, the ions in the glass tend to nucleate and grow in the preset direction to form a nanocrystal structure with consistent orientation. According to the treatment, the precipitation position and the growth direction of the nanocrystals can be accurately controlled while the precipitation yield of the crystals is ensured.

The invention relates to the technical field of environmental engineering, in particular to a nucleation granulation modified seed crystal for recycling iodine in water and a coupling process. The modified seed crystal comprises a seed crystal and a coating layer coating the surface of the seed crystal, the coating layer comprises magnesium hydroxide and aluminum hydroxide, and the modified seed crystal has a porous structure. The modified seed crystal provided by the invention has excellent catalytic activity, can effectively improve the oxidation efficiency of iodide ions when being applied to recovery of iodine elements in water, provides abundant adsorption active sites for heterogeneous nucleation of iodide ion oxidation products, and promotes nucleation growth of the iodide ion oxidation products. According to the invention, efficient recycling of iodine resources in water is realized by using a pre-oxidation-nucleation granulation coupling process, and the problems of low recovery efficiency of iodine ions in water, high operation cost, high recovery difficulty and the like in the existing process are solved.

The invention provides a method for preparing a supported nano noble metal by introducing a closed borane cluster into an MXene matrix, and belongs to the technical field of nano noble metal materials. A closed borane cluster is introduced into an MXene matrix to prepare a supported nano noble metal, the closed borane cluster (a weak reducing agent) with weak reducing capacity is pre-arranged on the surface of MXene in a solvent removal in-situ nucleation growth mode, then noble metal salt is introduced, in-situ reduction of the noble metal salt on the surface of MXene can be achieved, the noble metal salt is attached to the surface of MXene, and the supported nano noble metal is prepared. Controllable reduction of precious metal ions is achieved, and then the structure of the material is stabilized through high-temperature annealing treatment, so that the load type nanometer precious metal material with the small size and the high dispersity is obtained.