1346 results about "Low oxygen" patented technology

A hydrogen gas sensor with a substrate and a zinc oxide nanostructured thin film deposited on the substrate, wherein the zinc oxide nanostructured thin film has a lattice structure with a weight ratio of low binding energy O2− ions to medium binding energy oxygen vacancies in a range of 0.1 to 1.0, and a method of fabricating a gas sensor by thermally oxidizing a metal thin film under low oxygen partial pressure. Various combinations of embodiments of the hydrogen gas sensor and the method of fabricating the gas sensor are provided.

The invention relates to the technical field of sewage treatment, in particular to an aerobic aeration treatment system for plateau domestic sewage treatment, which comprises a pretreatment unit, a biological treatment unit, an advanced treatment unit and a recycling unit which are connected in sequence, the system further comprises a data acquisition module, an aerobic aeration intelligent regulation and control module, a biochemical environment constant-temperature maintenance module, a carbon-nitrogen proportion and backflow dynamic regulation and control module, a digital twinning and sludge characteristic simulation module and an energy collaborative scheduling module. Compared with the prior art which adopts a standard aeration strategy and cannot adapt to the special environment of low air pressure and low oxygen partial pressure of the plateau, the system can accurately adapt to the plateau environment by integrating real-time atmospheric pressure and water temperature monitoring, dynamically calculating the oxygen saturation solubility and correcting the aeration control target according to the oxygen saturation solubility, so that the aeration control target is optimized. Stable supply of dissolved oxygen required by biochemical reaction is ensured, and the technical bottleneck of low efficiency of traditional sewage treatment in plateau regions is fundamentally overcome.

The invention discloses an efficient regulation and control system and method for plateau low-oxygen environment damage, and relates to the technical field of human body low-oxygen damage analysis, detection and regulation and control, and the system comprises a data monitoring module, a signal screening module, a decision oxygen distribution module and a monitoring interaction module; the data monitoring module is used for acquiring a physiological state related to the plateau hypoxia adaptive capacity in real time; acquiring physiological data with high modeling value through an optimization algorithm by using a signal screening module based on test data, and constructing a discrete state space model of a physiological state; an oxygen distribution concentration decision is determined through a predictive control algorithm by utilizing a decision oxygen distribution module, so that oxygen supply regulation and control are realized; and the monitoring interaction module is used for storing, recording and displaying data, issuing an alarm and predicting dangerous conditions. Therefore, by means of the method, effective oxygen supply, blood oxygen dynamic monitoring and real-time alarming can be achieved, and health and safety of individuals in oxygen-deficient environments such as high-altitude areas and the like are guaranteed.

The invention provides a metallurgical process optimization method and system for a low-oxygen low-nitrogen aluminum-vanadium alloy, and relates to the technical field of process optimizing.The method comprises the steps that correlation characteristics among process parameters are extracted through a three-layer gating map attention network, and a parameter coupling state vector is constructed in combination with a time sequence attention module; constructing a process prediction model based on the state vector, and fusing a thermodynamic equilibrium equation and a long-short term memory network to predict the oxygen and nitrogen content; a deep reinforcement learning network of a Soft Actor-Critic algorithm is adopted, the parameter coupling state vector and the oxygen and nitrogen content prediction value serve as state input, and the technological parameter adjustment amount is output; and planning and iteratively training a future adjustment strategy through Monte Carlo tree search to finally obtain an optimal process parameter combination meeting oxygen and nitrogen content constraints, thereby realizing intelligent optimization control of the metallurgical process.

The invention provides a method for detecting silicon single crystal COP free area distribution, and relates to the technical field of silicon single crystal quality detection.The method comprises the steps that a silicon wafer to be detected is cleaned to obtain a first silicon wafer; uniformly smearing a transition metal ion solution on the surface of the first silicon wafer to obtain a second silicon wafer; placing the second silicon wafer in a high-temperature environment, and performing heat treatment under three temperature gradients to obtain a third silicon wafer; wherein in the first stage, transition metal ions are diffused to the surface layer of the silicon wafer to activate oxygen precipitates in a Pv region, in the second stage, the transition metal ions are promoted to be diffused into the silicon wafer to develop a Pi low-oxygen region, and in the third stage, nuclei coalescence in a B-band region is activated at high temperature to form a differential arrangement ring; cleaning the third silicon wafer through a mixed acid solution to obtain a fourth silicon wafer; and placing the fourth silicon wafer in a preferential corrosion liquid for preferential corrosion, and carrying out COP free area distribution detection on the obtained detection sample wafer. According to the scheme, the definition of each region boundary can be improved, so that the detection accuracy of COP free region distribution is improved.

The invention relates to a non-noble metal-based self-supporting electrode, a preparation method thereof and application of the non-noble metal-based self-supporting electrode in efficient electrolyzed water. The self-supporting electrode comprises a non-noble metal substrate layer, and a transition layer and a catalytic activity layer which are sequentially arranged on the surface of the non-noble metal substrate layer, the transition layer comprises NiFe unit cell nano particles; the catalytic activity layer comprises CoFeLDH, and the CoFeLDH is of a cactus spherical structure formed by a nano needle-shaped array; and a heterojunction interface is arranged between the transition layer containing the NiFe unit cell nanoparticles and the catalytic activity layer containing the CoFeLDH. The catalyst has low oxygen evolution overpotential and has high current density and excellent stability under the working condition, the transition layer is constructed between the catalytic active layer and the foamed nickel substrate, interface contact between the catalytic active layer and the substrate can be optimized, more uniform stress distribution and better interface adhesion can be achieved, charge transfer and mass transfer are enhanced, and the catalytic activity of the catalyst is improved. Therefore, the electrode interface stability is realized.

The invention relates to a titanium oxide nanowire supported iridium catalyst as well as a preparation method and application thereof. The catalyst comprises a titanium oxide nanowire carrier and elemental iridium supported on the titanium oxide nanowire carrier. According to the catalyst, the titanium oxide nanowire is used as a carrier, and the catalyst prepared by loading elemental iridium on the titanium oxide nanowire is used as an anode catalyst, so that higher mass specific activity and lower oxygen evolution overpotential can be obtained; the membrane electrode prepared by using the composite material has the characteristics of low noble metal catalyst loading capacity and low electrolytic water decomposition voltage.

The invention relates to the field of crystal preparation, in particular to a production device and a preparation method of monocrystalline silicon, the monocrystalline silicon and an insulated gate bipolar transistor. The apparatus for producing monocrystalline silicon comprises: a crucible for placing and melting a raw material; the heating module is arranged around the crucible and comprises a fixed heater at the upper part and a movable heater at the lower part, and the movable heater moves along the lifting direction of the crystal bar so as to accurately control the crystal growth temperature gradient and the oxygen diffusion transmission mode at different stages of crystal growth; and the magnetic field module is used for applying an asymmetric hook-shaped magnetic field in the crystal growth process so as to inhibit convection of raw materials in the crucible, reduce the oxygen concentration and improve the radial uniformity of oxygen. According to the technical scheme, on the basis of 300mm N-type monocrystalline silicon, under low oxygen (lt; 5ppma), ROGlt; and on the basis of 10%, the target of low potential type defect density can also be achieved, so that the high-quality requirements, including ultralow oxygen content, low defect density and the like, of an IGBT (Insulated Gate Bipolar Translator) on a silicon single crystal substrate are met. The efficient preparation of the ultralow-oxygen N-type silicon single crystal is realized by combining a heater with a novel structure with a CUSP magnetic field technology and matching with crystal pulling process parameter optimization. According to the silicon single crystal prepared by the method, the performance and the reliability of an IGBT (Insulated Gate Bipolar Translator) can be remarkably improved, the production cost is reduced, and the requirements of modern power electronic devices on high-performance silicon-based materials are met.

The invention provides a low-oxygen high-strength TZM alloy material and a preparation method thereof. According to the low-oxygen high-strength TZM alloy material, the crystal grains are of an isometric crystal structure, random orientation is achieved, all-directional performance is consistent, and the average crystal grain size ranges from 25 micrometers to 35 micrometers. The TZM alloy material has the advantages of being high in density, low in oxygen content, high in strength, high in heat dissipation capacity, good in thermal shock resistance and the like.

The invention relates to the technical field of food preservation, in particular to a vegetable preservation method based on an ultralow-temperature quick-freezing technology. Comprising the following steps: carrying out cleaning and impurity removal treatment on vegetables to be preserved; rapidly cooling the treated vegetables to a temperature ranging from-40 DEG C to-78 DEG C by using an ultra-low temperature technology for not less than 10 minutes; putting the quick-frozen vegetables into a vacuum package, and keeping the freshness of the vegetables in a low-oxygen environment; a natural antioxidant is added in the packaging process, so that the storage life of the vegetables is further prolonged. According to the vegetable fresh-keeping method based on the ultralow-temperature quick-freezing technology, the freezing technology and packaging materials are optimized, so that the storage time of the vegetables is effectively prolonged, and meanwhile, the original color, texture and nutritional ingredients of the vegetables are kept.

The invention relates to the technical field of plant cultivation, and discloses a method for improving low-temperature and low-oxygen composite stress resistance of tobacco seedlings by exogenous amino acids, which comprises the following steps: selecting tobacco seedlings in a two-leaf and one-core stage of floating seedling raising; preparing an L-pyroglutamic acid mother solution; performing exogenous treatment on the selected tobacco seedlings in the two-leaf and one-core stage by using the prepared L-pyroglutamic acid mother liquor; after treatment is completed under the low-temperature and low-oxygen condition for 3 days, taking a picture of a tobacco seedling, recording phenotype, sampling roots, and measuring root length and root activity; according to measured values under the treatment of adding different volumes of L-pyroglutamic acid mother liquor with the concentration of 1g / L, data is sorted by software, difference significance analysis is carried out by data processing software, and comprehensive evaluation is carried out by a multi-character fuzzy membership function method. The application comprehensively evaluates the effect of the L-pyroglutamic acid in improving the low-temperature and low-oxygen stress resistance of the tobacco seedlings, and provides important theoretical basis and practical guidance for improving the crop stress resistance in agricultural production.

The invention provides a medical TA4G pure titanium wire bar and a preparation method thereof. According to the preparation method of the medical TA4G pure titanium wire bar, firstly, alloy raw materials are subjected to vacuum consumable smelting, a first alloy ingot is obtained, and then cogging forging is conducted; carrying out multidirectional forging and water quenching treatment on the blank; then the blank is subjected to precise radial forging; and finally, after multi-pass small-deformation hot rolling is conducted on the blank, cold rolling is conducted, annealing is conducted after cold rolling, and the medical TA4G pure titanium wire bar is obtained. According to the method, the oxygen content is limited, and the medical low-oxygen high-performance TA4G pure titanium wire bar is finally obtained through the processes of repeated vacuum consumable smelting, cogging forging, multidirectional forging water quenching treatment, multi-pass small-deformation hot rolling, cold rolling and annealing. The invention also provides the medical TA4G pure titanium wire bar prepared by the method provided by the invention.

The invention provides a method for detecting oxygen content in copper / copper alloy, and belongs to the technical field of metal component analysis. According to the method for detecting the oxygen content in the copper / copper alloy, the mixed solution of nitric acid, hydrofluoric acid and water is used for cleaning the sample, nitric acid can perform corrosion cleaning on the sample, and when oxide or nitride which is difficult to dissolve by nitric acid exists on the surface of the sample, the oxygen content in the sample is detected by utilizing the characteristic of small molecular radius of hydrogen fluoride. The cleaning agent can rapidly penetrate through a compact metal oxide layer, reacts with metal oxide, destroys and dissolves the metal oxide layer, effectively cleans impurities such as oxide and nitride on the surface of a sample, and is beneficial to improving the accuracy of oxygen content testing. The fluxing agent and the sample are heated and melted together, so that the melting point of copper or copper alloy can be reduced, covalent bonds are destroyed, oxygen release is facilitated, and the detection accuracy is further improved; and the fluxing agent is used, so that the stability of low oxygen content detection is improved, and the detection of lower oxygen content is realized.

The invention belongs to the technical field of nano materials, and relates to a carbon thermal reduction driven high-entropy oxide metastable-state material and a preparation method and application thereof.The preparation method comprises the steps that S1, carbon and soluble metal salt are dissolved in a solvent for ultrasonic treatment, and a metal salt solution and a carbon suspension are obtained; s2, adding a metal salt solution into the carbon suspension, adding strong base, and stirring to obtain a coprecipitation polymer; s3, re-dispersing the coprecipitation polymer in the solvent, adding extra ferric salt and urea, mixing and stirring, and freeze-drying the mixed solution to obtain precursor powder; s4, performing staged annealing treatment on the precursor powder under low oxygen partial pressure to obtain a carbon-loaded high-entropy oxide metastable-state material; the prepared high-entropy oxide metastable-state material is of an alloy phase and high-entropy oxide double-phase coupling structure, the polarization loss of electromagnetic waves is enhanced through a heterogeneous interface, and the high-entropy oxide metastable-state material has the advantages of being excellent in impedance matching and wide in electromagnetic wave absorbing bandwidth and can be widely applied to the fields of industrial electronics, medical communication and military stealth.

The invention discloses a method for refining grains of a titanium alloy. According to the method, an original low-oxygen-content titanium alloy plate is subjected to cryogenic pretreatment, the temperature of the core of the original low-oxygen-content titanium alloy plate is reduced to a certain temperature, then the cryogenic low-oxygen-content titanium alloy plate is fed into a rolling mill, the single-pass reduction rate is controlled, cryogenic rolling is completed, high refinement and uniform distribution of crystal grains are achieved, and the low-oxygen-content titanium alloy plate is obtained. And the rolled titanium alloy plate is subjected to subzero treatment again, and the titanium alloy plate of the complex twin crystal structure formed by intersection of {11-22} and {10-11} twin crystals is obtained. The method has the beneficial effects that under the synergistic effect of low oxygen and deep cooling, even under the extremely small deformation amount, the cross effect of various twin crystal systems can be efficiently activated, a high-density and complex twin crystal structure is formed, high refinement and uniform distribution of crystal grains are achieved, then the mechanical strength and low-temperature toughness of the material are remarkably improved, and the service life of the material is prolonged. And the application requirements in a severe low-temperature service environment are met.

The invention discloses a preparation method of niobium-tungsten alloy spherical powder and a 3D printing method of the niobium-tungsten alloy spherical powder, and belongs to the technical field of refractory metal material preparation.The preparation method comprises the steps that niobium, tungsten, molybdenum and zirconium refractory metal raw materials are smelted to obtain cast ingots with uniform components, and hydride powder is formed after hydrotreating and mechanical crushing; spherical powder is prepared by adopting a plasma spheroidizing technology, then dehydrogenation is performed for 1-3 hours at the temperature of 450-750 DEG C, magnesium powder is added, treatment is performed for 2-5 hours in an inert atmosphere at the temperature of 800-1100 DEG C, and finally the low-oxygen niobium-tungsten alloy spherical powder with the oxygen content lower than 120 ppm is obtained. Compared with a traditional process, the spheroidizing treatment is innovatively carried out before the dehydrogenation and oxygen reduction process, the deoxidation efficiency is improved through the relatively small specific surface area of spherical powder, and oxygen content control is achieved in combination with magnesium powder heat treatment. The problems of high oxygen content and low powder yield in a traditional process are solved, and material support is provided for high-performance niobium-tungsten alloy components in the fields of aerospace, nuclear power and the like.

The invention discloses a method for researching the repairing effect of low-pressure and low-oxygen exercise on waist polyfidus injury, which comprises the following steps: S1, selecting and grouping experimental animals: selecting healthy adult rats, and randomly dividing the healthy adult rats into a plurality of experimental groups including a conventional exercise group, a low-pressure and low-oxygen exercise group, a low-pressure and low-oxygen treatment group and a control group; s2, setting a low-pressure and low-oxygen exercise environment: simulating a high-altitude environment by using a low-pressure oxygen cabin; the treadmill is used for rat running exercise; and S3, exercise plan implementation: performing exercise training on all the rats in the experimental group on the five-channel running machine. According to the invention, exercise training is carried out in a low-pressure and low-oxygen environment, so that a new physical intervention means is provided for rehabilitation treatment of waist muscle injury; researches show that movement under low-pressure and low-oxygen conditions is beneficial to acceleration of regeneration and repair processes of muscular tissues, which is crucial for rapid recovery of normal functions after acute or chronic waist injury.

The invention provides a low-pressure low-oxygen training cabin control method, which is applied to a training cabin in a low-pressure low-oxygen environment, and comprises the steps: responding to a simulated target altitude, calling target air pressure corresponding to the target altitude, and adjusting the environment air pressure of the training cabin to the target air pressure; setting the simulation training duration of the training cabin, and respectively adjusting the oxygen concentration of the training cabin and the environment temperature of the training cabin to a target concentration and a target temperature; detecting the pressure, oxygen concentration and temperature of the training cabin, and performing wind power simulation in the low-pressure low-oxygen training cabin based on a preset training rule; and continuously monitoring the physiological index data of the personnel in the cabin until the simulation training duration is ended. The air pressure condition of a specific plateau environment can be quickly and accurately simulated, and the stability and consistency of the training environment are ensured. The basic and accurate automatic control of the training cabin environment is realized, and the training efficiency and effect are effectively improved.

The invention provides a preparation method and application of mesenchymal stem cell exosomes, and the method is characterized in that N-acetylcysteine and quercetin are added into a culture medium used for culturing MSC cells, so that the MSC cells are stimulated to generate exosomes with anti-aging and anti-apoptosis effects. In addition, the exosome generated by stimulating the MSC through a culture mode of gradually reducing oxygen partial pressure further has an anti-aging effect; the adverse effects of acute oxidative stress, decline of multiplication capacity, unstable quality and the like in a low-oxygen state can be inhibited, and the activity of related components of cells and exosomes is not damaged. The method shows good anti-aging and anti-apoptosis effects in vitro, and a new thought is provided for treating aging diseases by the exosome in the future.

The invention belongs to the technical field of electronic packaging and welding materials, and relates to lead-free solder powder for reflow soldering and a preparation method of the lead-free solder powder. The lead-free solder powder is based on a Sn-Ag-Cu alloy system, and melt purification, beta-Sn grain refinement and interface IMC stabilization are achieved by compositely adding trace Ce and Ni elements. The Sn-Cu-Ce alloy comprises the following components in percentage by mass: 2.9%-3.1% of Ag, 0.45%-0.55% of Cu, 0.01%-0.10% of Ce, 0.01%-0.05% of Ni and the balance of Sn and impurities. During preparation, a Ce-Ni intermediate alloy is adopted to introduce microalloy elements, and the spherical solder powder is obtained through vacuum melting, inert gas atomization and surface treatment. The obtained solder powder is low in oxygen content, good in wettability, slow in interface IMC growth after backflow, high in welding spot strength and excellent in thermal cycle reliability, and is suitable for the field of high-reliability electronic packaging.

The invention discloses a leakage rate detection device and method for gloves of a glove box, and the device comprises a detection cabin which is provided with a cavity and a glove installation part, and the glove installation part is located at one end of the cavity and is fixedly connected with the cavity; the glove mounting piece is provided with a hollow circular opening protruding part, and the glove to be detected, the protruding part and the cavity jointly form a space to be detected; the vacuum pump is used for extracting air in the to-be-detected space; the nitrogen source works cooperatively with the vacuum pump and is used for injecting nitrogen into the to-be-detected space so as to reduce the oxygen content of the to-be-detected space; and the oxygen adsorption circulating system further adsorbs and purifies oxygen in the cavity on the basis of collaborative oxygen removal of the vacuum pump and the nitrogen source so as to provide a low-oxygen environment. By means of the device, the glove leakage rate is calculated by comparing the oxygen concentration change of the standard glove and the to-be-detected glove, and by means of multi-stage parameter correction and multi-sealing design, the glove leakage rate is improved, and the reliability of the glove leakage rate is improved. The equipment background leakage rate is effectively reduced, and the reliability of a test result is improved.

The invention discloses a water quality monitoring device and a monitoring method thereof, belongs to the technical field of water quality monitoring, and solves the problems that trace hydrogen sulfide generated by sulfate reducing bacteria in a deposited layer at the bottom of a water tank which is not cleaned for a long time in a low-oxygen environment reacts with a platinum membrane electrode of a residual chlorine sensor to generate a platinum sulfide covering layer; and the electrode reading is continuously virtually high and drifts slowly. Comprising an optical transmitting module, an optical receiving module, a spectrum separation module, a signal conditioning module, a lock-in amplification module, a spectrum feature extraction module and a hydrogen sulfide recognition engine. Residual chlorine is monitored in a non-contact mode, deep ultraviolet pulse light is emitted to penetrate through a water body, a reflection spectrum is received, second derivative spectral characteristics are extracted through multichannel signal processing, and multivariable regression compensation is executed to calculate a real residual chlorine value after hydrogen sulfide interference characteristics are recognized. Meanwhile, the drift trend is quantified based on the double-time-constant integral, graded early warning is triggered, industrial standard signals are finally output, and the problem of electrode contact pollution is avoided in the whole process.

The invention discloses a low-oxygen high-purity zinc small ingot forming glove box device, which relates to the technical field of oxygen-free glove boxes, and comprises a box body, a glove box door arranged on one side of the box body, a glove opening arranged on one side of the box body, and a vacuum extraction system, the heating device is arranged on one side in the box body, the mold assembly is arranged on the other side in the box body, the crucible assembly is heated through the heating device, the transferring mechanism drives the crucible assembly to move and ascend and descend, the pouring assembly is used for pouring materials in the crucible assembly into the mold assembly, and the pouring assembly is located between the transferring mechanism and the mold assembly. The transfer mechanism, the dumping assembly and the mold assembly are sequentially lowered in height. The device is reasonable in design and ingenious in structural design in the transferring and transferring process, zinc materials are molten in the glove box, the glove box is vacuumized and then filled with inert gas, the zinc materials are prevented from being oxidized in the forming process, in addition, the transferring mechanism drives the crucible assembly to move and ascend and descend, and the dumping assembly assists the crucible assembly in obliquely dumping materials. By arranging the glove box, the product quality and the working efficiency are improved.

The invention discloses a low-temperature-resistant hydrogen energy unmanned aerial vehicle system capable of adapting to high-altitude flight. The low-temperature-resistant hydrogen energy unmanned aerial vehicle system comprises an unmanned aerial vehicle body, a hydrogen energy fuel cell module, a driving module and a control module, the hydrogen energy fuel cell module generates electric energy through hydrogen and oxygen and provides the electric energy to the driving module, and the driving module drives the unmanned aerial vehicle body to fly; and the control module controls the hydrogen energy fuel cell module according to the flight height and the flight environment temperature of the unmanned aerial vehicle body and the residual hydrogen content in the hydrogen storage bottle, so that the hydrogen energy fuel cell module works in one of the following modes: an intelligent high-altitude oxygen supply mode, a weight-reduction endurance mode and a low-temperature-resistant mode. According to the invention, the problems of low temperature and low oxygen in high-altitude flight can be well solved, and the application prospect is wide; the control module can autonomously select an intelligent high-altitude oxygen supply mode, a weight-reduction endurance mode or a low-temperature-resistant mode to work according to the flight environment and the state of the unmanned aerial vehicle.

The invention discloses a high-purity ruthenium target material for sputtering and a preparation method thereof, and belongs to the technical field of target material preparation. The density of the high-purity ruthenium target for sputtering is larger than or equal to 99.5%, the oxygen content is smaller than 200 ppm, and the average grain size of ruthenium is smaller than 10 micrometers. The preparation method comprises the steps that ruthenium powder is put into a die to be pre-pressed after being put into a vacuum hot-pressing sintering furnace, then under the vacuum condition, gradient heating is conducted to the sintering temperature of 1000-1200 DEG C, then heat preservation is conducted, gradient pressurization is conducted to the hot-pressing pressure of 35-40 MPa, hot-pressing sintering is conducted for 90-150 min, then furnace cooling is conducted, a ruthenium pre-target blank is obtained, the ruthenium pre-target blank is put into a hot isostatic pressing sintering furnace after being subjected to sheathing degassing, and the ruthenium target blank is obtained. And sintering for 3-5 hours at the temperature of 1300-1450 DEG C under the pressure of 110-160 MPa under the vacuum condition, cooling along with the furnace, recovering the pressure, and machining to obtain the finished ruthenium target with high density, high purity, low oxygen content and uniform and fine grain structure.

Disclosed in the present application are a battery, a gas sensing material and a preparation method therefor, a sensor and an electric device. The battery comprises a gas sensor, which comprises a gas sensing material, wherein the gas sensing material comprises an M / MXene composite material, the M / MXene composite material comprising a metal (M) monoatom and an MXene material, and / or comprising a metal (M) cluster and an MXene material. The gas sensing material provided by the present application can achieve the detection of a target gas in an oxygen-free or low-oxygen environment and the detection of gas production within a battery. Furthermore, the sensitivity and selectivity of gas detection can be improved, the response and recovery speeds can be increased, and the detection limit of a gas can be reduced.

The invention discloses a method for preparing low-oxygen tantalum powder through magnesium reduction. Aiming at the defects of more impurities, non-uniform particles, complex process and the like in the existing tantalum powder preparation technology, the method comprises the following steps: firstly, pretreating tantalum oxide powder and anhydrous calcium chloride, so that tantalum oxide is uniformly coated with calcium chloride; and mixing the pretreated raw materials with magnesium chips, introducing high-purity argon into a closed container for multiple times of replacement, carrying out heating and heat preservation to generate a reaction, separating a product, and then carrying out water washing, acid pickling and drying treatment to obtain the tantalum powder. According to the method, magnesium and tantalum oxide are fully reacted by virtue of heat absorption and fluxing effects of calcium chloride, so that composite substances such as tantalate are prevented from being generated, and impurity introduction is reduced. The oxygen content of the prepared low-oxygen tantalum powder is smaller than 3000 ppm, the apparent density is 1.3-1.5 g / cm < 3 >, powder particles are in a coralline shape and are uniform in size, operation is easy and convenient, the requirement for equipment is low, and the low-oxygen tantalum powder has good application prospects in the field of electronic component manufacturing.

The invention provides a method for degrading a perfluoroalkyl compound by activating peroxymonosulfate based on a graphite electrode. Comprising the following steps: step 1, pretreatment of a graphite rod electrode: soaking the graphite rod electrode in a sulfuric acid solution to remove surface impurities; step 2, preparing an electrolyte: preparing the electrolyte containing a perfluoroalkyl compound to be degraded, a background supporting electrolyte and peroxymonosulfate (PMS), and fully stirring to ensure uniform distribution; and step 3, inserting the pretreated graphite rod electrode into electrolyte in an electrolytic bath, adjusting current and voltage, and carrying out electrolysis under the condition of solution stirring. According to the method, the feasibility of activating the PMS to degrade the perfluoroalkyl compound by the low-oxygen-evolution-potential electrode is proved for the first time, and the cognitive limitation of the traditional technology is broken through; the prior art generally depends on a high oxygen evolution potential electrode (such as a BDD electrode, and the oxygen evolution potential is larger than 2.0 V / SHE) to activate PMS so as to degrade perfluoroalkyl compounds.

The invention provides a high-efficiency low-pollution cow dung returning treatment method, which comprises the following steps: adding corn straw and charcoal into cow dung, preparing a fermentation base material, inoculating a compound fermentation inoculant, and carrying out composting fermentation to prepare a cow dung organic fertilizer. The composite microbial inoculant adopts an inner and outer double-film coating structure, aerobic bacteria are embedded in the middle, are released in the early stage of composting, quickly enter a high-temperature stage and decompose and metabolize organic matters, anaerobic bacteria are embedded in the innermost layer, and an inner film coating material adopts composite modified waterborne polyurethane, so that the composite microbial inoculant has a good anti-bacterial effect. Azobenzene and waxberry tannin combined modification endows the membrane structure with the characteristics of low-oxygen cracking, normal-oxygen stability and no influence of enzyme, anaerobic bacteria are released under the low-oxygen condition in the high-temperature last stage and the decomposition period, decomposition of residual cellulose can be promoted, carbon and nitrogen loss caused in anaerobic fermentation is prevented, the speed of converting organic matter into humus is increased, and the yield of the organic matter is increased. Meanwhile, the inner film packing material reacts with the organic acid and the ethanol, so that the quality of the cow dung organic fertilizer is further ensured.

The invention discloses a multifunctional nano-carrier with drug resistance, biotin receptor targeting and hypoxia / low pH dual responsiveness and a preparation method and application thereof, and belongs to the technical field of biomedical polymer materials. The AGT inhibitor conjugate with biotin receptor targeting and low oxygen and low pH dual response provided by the invention comprises a hydrophobic 2-amino-O4-benzyl pteridine group (BD), a low oxygen response group azobenzene (AZO) and a hydrophilic high polymer material modified by biotin (Bio). According to the system, hydrophobic chemotherapeutic drugs can be loaded in a drug carrying system through intermolecular acting force, target biotin receptors on tumor cells and are enriched in tumor tissues by utilizing high permeability and long-term effectiveness of the hydrophobic chemotherapeutic drugs; the tumor microenvironment characterized by low oxygen and low pH can induce azo bond breakage and pH response on the nano-carrier to release BD with AGT activity inhibition and an alkylating agent with anti-tumor activity, so that the drug resistance and anti-tumor activity of the drug are improved, and the targeting property is increased.