409 results about "Inductively coupled plasma" patented technology

The invention discloses an individual tree segmentation method based on machine learning, and particularly relates to the field of individual tree segmentation. The method comprises the following steps: respectively acquiring forest point cloud data through a ground scanner and an unmanned aerial vehicle, registering the forest point cloud data into a complete data set, preprocessing the point cloud data, extracting geometric, reflective and spatial distribution multi-dimensional features, and fusing the geometric, reflective and spatial distribution multi-dimensional features into a comprehensive feature vector; training a model by using a machine learning method based on the labeled data, taking the feature vector as input, and outputting whether the point belongs to a tree or not; predicting a point category by using the trained model, performing individual tree instance segmentation by using a connected component clustering and graph segmentation method through CRF post-processing optimization, constructing a 3D model and calculating key parameters; and finally, performing post-processing on a preliminary segmentation result, filtering noise by using connected region analysis, filling the deficiency by using a three-dimensional hole, optimizing a boundary based on graph segmentation, and optimizing a block seam by using an ICP (Inductively Coupled Plasma) algorithm.

The invention discloses a tunnel back break analysis method based on a dynamic center line and an incremental convex hull, and belongs to the technical field of tunnel engineering detection. According to the system, the problems that a traditional detection method is low in efficiency and large in error are solved by fusing dynamic slice projection, robust registration and intelligent contour generation technologies. The method specifically comprises the following steps: carrying out configurable downsampling (the density is reduced to 0.2%-0.5% at an interval of 50-1000 points) on an original point cloud, constructing a tunnel three-dimensional model (the side length of a grid is less than or equal to 0.1 m) by adopting a dynamic center line extraction algorithm, and carrying out ICP (Inductively Coupled Plasma) registration (error lt; the method comprises the following steps of: synchronously extracting a design / actual measurement section contour by using a combined slicing technology, generating an actual measurement polygon based on an incremental convex hull algorithm (a filtering threshold value is 20 points), and calculating an over-break volume (an error is less than or equal to 1.5%) by using a spatial Boolean operation. A dynamic center line extraction and incremental convex hull algorithm is innovatively introduced, automatic generation of a color gradation analysis atlas (over-excavation RGB (255, 69, 0) and under-excavation RGB (30, 144, 255)) is supported, and full-process closed-loop processing is realized.

The invention discloses a subway protection area intelligent patrol system based on an unmanned aerial vehicle. The system comprises a data acquisition module which collects multi-dimensional area data in real time through a multi-mode sensor; the feature acquisition module is used for generating a dynamic implicit field through a DNIF encoder to automatically extract space-time continuous difference features; the difference acquisition module is used for introducing an improved ICP (Inductively Coupled Plasma) registration algorithm to carry out registration comparison on the point cloud data on the basis of space-time continuous difference characteristics to obtain optimized point cloud data differences, and obtaining a comprehensive difference degree on the basis of the optimized point cloud data differences; and the abnormity patrol module obtains a foreign matter behavior mode around the track through an optimized Kalman filtering model, maps the foreign matter behavior mode and the comprehensive difference degree into a causal graph model to generate an optimal patrol decision, improves the scientificity and timeliness of the decision, and optimizes patrol resource configuration at the same time.

The invention discloses an ultratrace mercury isotope analysis method, and relates to the technical field of environmental analysis. The method comprises the following steps: purging a liquid sample to be detected by nitrogen in a stannous chloride atmosphere, and trapping and concentrating mercury into a gold trapping tube; pyrolyzing the pyrolytic gold trapping tube to release mercury vapor; pyrolytic mercury vapor and thallium isotope internal standard aerosol are mixed to serve as a sample injection sample, and the sample injection sample is introduced into a multi-receiver inductively coupled plasma mass spectrometry; acquiring a mercury instantaneous signal and a thallium isotope signal; and calculating the mercury isotope ratio by adopting least square linear regression fitting in combination with a thallium internal standard ratio correction algorithm. According to the method, the instantaneous mercury isotope signal is generated by online combination of gold trapping and multi-receiver inductively coupled plasma mass spectrometry, the instantaneous signal is strategically collected and processed, the determination concentration of isotope analysis can be greatly reduced, the sensitivity of the method is remarkably improved, and direct determination of mercury isotope composition in a water sample with the concentration of 10 ng L <-1 > is met.

A hybrid inductively coupled plasma mass spectrometer (ICP-MS) system is disclosed for simultaneous elemental and molecular analysis in positive and negative polarities. It includes an ICP torch that generates plasma with a buffer gas, producing both positively and negatively charged ions from a sample. Positioned between the sampler and skimmer, an insert with a defined geometry forms a reaction chamber. Various embodiments feature multiple apertures for pressure control, a rotatable disk for aperture regulation, a slider gate for pressure adjustment, a circular gate with adjustable radial apertures, and an inlet for introducing gases, reagents, dopants, or analytes. These components enable precise pressure modulation, optimizing performance for dual-polarity mass spectrometry. The system enhances analytical flexibility by facilitating controlled ion reactions, improving sensitivity and specificity for both elemental and molecular applications. This innovation expands ICP-MS functionality, supporting diverse scientific and industrial applications requiring high-precision mass analysis.

The invention relates to the field of test and analysis of impurity element content of primary magnesium ingots, in particular to a method for testing impurity element content of primary magnesium ingots by ICP (inductively coupled plasma) spectrometry, which comprises the following steps: firstly adding H2O2 into a magnesium ingot sample to infiltrate the sample, then adding HCl at an interval of less than 1 minute to carry out first reaction, carrying out first heating after the reaction is finished, and then carrying out second heating, cooling to 20-30 DEG C, transferring to a volumetric flask, and fixing the volume by using third-level water to obtain a sample solution; establishing a working curve by using an ICP spectrometer and a standard solution; testing the sample solution; the ratio of the mass of the magnesium ingot sample to the volume of H2O2 to the volume of HCl is 1: (3-10): (30-54), the method fills the standard vacancy of ICP spectrometry analysis of the silicon element in the primary magnesium ingot, a reliable basis is provided for chemical component analysis of the primary magnesium ingot, the test result is surface, and the method for testing the mass fraction of the impurity elements in the primary magnesium ingot provided by the invention has the advantages of high analysis precision, simple operation, high accuracy and high reliability. The analysis period is short, and related chemical varieties are few.

The invention discloses a method for determining the content of trace holmium, thulium and tungsten in rare earth erbium and a compound thereof, which comprises the following steps: placing a rare earth erbium and compound sample thereof in a beaker, and performing a blank test along with a sample; adding nitric acid, heating at low temperature until the sample is completely dissolved, and cooling; transferring into a volumetric flask, adding a cesium internal standard solution, diluting with water, and uniformly mixing; the holmium, the thulium and the tungsten are measured by using an oxygen mode of an inductively coupled plasma tandem mass spectrometer, and the contents of the holmium, the thulium and the tungsten are calculated according to a working curve method. According to the method, the inductively coupled plasma tandem mass spectrometry technology is used, and mass spectrum interference of an erbium matrix on holmium, thulium and tungsten is effectively eliminated by selecting a proper reaction mode and optimizing the flow of reaction gas.

The invention belongs to the technical field of chemical detection, and particularly relates to a method for detecting the content of boron in soil and sediment, which comprises the following detection methods: S1, weighing a sample and putting the sample into a digestion tank; s2, adding a digestion solution into the digestion tank; s3, after uniform stirring, putting the digestion tank into a microwave digestion instrument for microwave digestion; s4, after digestion is completed, closing the microwave digestion instrument, and after the digestion tank is cooled to the room temperature, filtering to remove precipitates; s5, transferring the digestion solution into a volumetric flask, and fixing the volume for subsequent analysis; and S6, analyzing the digestion solution by using ICP-OES / MS (Inductively Coupled Plasma-Optical Emission According to the method for detecting the boron content in the soil and the sediment, ammonium fluoride is used for replacing hydrofluoric acid in boron detection of the soil and the sediment, use of toxic reagents is reduced, mannitol is added, a stable complex is formed by mannitol and boron, and the recovery rate of boron is increased.

The invention relates to the technical field of mass spectrometer sampling, in particular to a sampling device of an inductively coupled plasma mass spectrometer, which comprises a bottom plate, and an inductively coupled plasma mass spectrometer body is fixedly mounted at the top of the bottom plate. During application, the sample introduction mechanism adopts a first motor to drive a turntable to carry a sample during use, power is amplified through transmission of a large belt wheel and a small belt wheel, and a non-contact magnetic coupling drives a pumping spiral driving blade to rotate to generate negative pressure, so that automatic sample extraction, negative pressure control of opening and closing of a plugging plate and accurate control of a sample conveying channel are realized; by means of the design, carrying power is converted into pumping power, the equipment structure is simplified, the number of parts and energy consumption are reduced, the equipment operation and maintenance cost is reduced, an automatic continuous sample injection process replaces traditional single-pipe extraction, the sample injection time is greatly shortened, and the sample treatment efficiency is improved.

The invention belongs to the technical field of geological sample analysis and detection, and particularly discloses a method for measuring the amount of each element of lithium ore in a closed acid-soluble system, and the method comprises the following steps: pretreating the lithium ore; the pretreated lithium ore is weighed and put into a closed sample dissolving device, hydrofluoric acid and purified nitric acid are sequentially added, and the closed sample dissolving device is closed; carrying out heat preservation on the closed sample dissolving device twice to obtain a test solution; and measuring the test solution by using an inductively coupled plasma mass spectrometer to obtain a working curve, and calculating the content of the analysis element in the sample solution by using the working curve. The method for determining the amount of each element in the lithium ore by adopting the closed acid-soluble system has the characteristics of simplicity in operation, high efficiency and good stability, realizes simultaneous determination of the amount of lithium, rubidium, cesium, beryllium, strontium, niobium, tantalum, zirconium, hafnium and rare earth elements in the large-batch lithium ore, and further provides a reference for determination of main trace elements in the lithium ore.

The invention provides a method for depositing silicon nitride on the side wall of a groove structure, and belongs to the technical field of semiconductor manufacturing. The method comprises the following steps of: depositing carbon-containing barrier layers on the top, the side wall and the bottom of a groove structure by utilizing inductively coupled plasma enhanced chemical vapor deposition, and then carrying out directional etching on the side wall of the groove by utilizing ammonia plasma bombardment, so that the carbon-containing barrier layers on the side wall of the groove are accurately removed, and the barrier layers in the top and bottom areas are kept complete; and finally, using inductively coupled plasma to enhance atomic layer deposition, and selectively depositing a silicon nitride film in the side wall area of the groove. The method does not need to depend on traditional photoetching and etching steps, non-target area deposition is avoided, the technological process is simplified, the deposition precision and the critical dimension control capability are improved, and the method has the dual control effects of precise directional etching and selective deposition.

The invention discloses a method for detecting the content of trace metal ions in a diazo naphthoquinone photosensitizer. The method comprises the following steps: sample pretreatment: weighing diazonaphthoquinone photosensitizer powder in a clean room, putting the diazonaphthoquinone photosensitizer powder into a cleaned and dried wide-mouth PFA bottle, adding an organic reagent, and carrying out ultrasonic treatment until a solid is completely dissolved; the method comprises the following steps: testing: adding a metal standard substance into an organic solvent to prepare three standard solutions with different concentrations; debugging an instrument, determining target metal in the standard solution in a Cool mode, a No Gas mode and a He mode by using an inductively coupled plasma mass spectrometer to obtain a signal intensity value (CPS value) corresponding to each metal ion concentration in the standard solution, and establishing a standard curve; and measuring the sample in which the photosensitizer is dissolved by using the same steps to obtain the content of metal ions in the sample. According to the method, appropriate detection conditions are optimized for different elements to be detected in the diazo naphthoquinone photosensitizer, polyatomic ion interference and matrix effect in a sample are mainly reduced, the content of 16 metal ions can be accurately detected at the same time, and the test efficiency is high.

The invention provides an infrared detector deep mesa etching process based on three layers of masks and an infrared detector, and belongs to the field of infrared detector mesa etching. The process comprises the following steps: spin-coating a stress buffer layer on the surface of a superlattice epitaxial layer, and curing and forming; depositing a hard mask serving as an etching barrier layer; depositing an inorganic oxide; spin-coating photoresist to form a composite patterned top layer, and then forming a mesa pattern through a photoetching process; taking the mesa pattern as a mask, and transferring the mesa pattern to the hard mask through reactive ion etching; etching the stress buffer layer by adopting plasma until the surface of the superlattice epitaxial layer is exposed; the three layers of masks are used as blocking, deep etching is carried out through inductively coupled plasma, and the etching depth is 5.6-6 microns; a post-processing step; according to the process provided by the invention, high-quality and high-aspect-ratio mesa etching can be realized on the premise of not introducing extra pollution and remarkably increasing the cost, and the process is suitable for preparing a deep-mesa and high-aspect-ratio device.

The invention relates to an edge calculation enabling tunnel back break real-time detection method and system, and belongs to the technical field of tunnel construction intelligent monitoring and quality control, and the method comprises the following steps: 1, collecting data in real time through array multi-mode sensors deployed on a tunnel excavation surface; 2, dynamically constructing a local BIM model at an edge computing node, and carrying out noise reduction processing on the point cloud data by adopting an adaptive voxel filtering algorithm; step 3, carrying out nonlinear registration on the real-time point cloud and the design model based on an improved ICP (Inductively Coupled Plasma) algorithm; 4, extracting back-break features through a lightweight convolutional neural network, and dynamically updating network parameters by adopting a transfer learning framework; step 5, generating an augmented reality visualization report including the back break amount, the spatial distribution and the risk level on the edge side, and transmitting the augmented reality visualization report back to the control center through the low-delay communication module; the method has the beneficial effects that the real-time point cloud and the design model are subjected to nonlinear registration, and the requirement of tunneling deviation is monitored in real time.

The present invention discloses a method for quantitative determination of trace harmful elements in various flotation products of rare polymetallic ores, which includes three parts: sample processing, preparation of complex matrix standard solution and sample testing. Each flotation product is digested with analytically pure concentrated nitric acid; the main mineral species of each product are determined by XRD, and the high-purity standard substances of each main associated mineral are digested with analytically pure concentrated nitric acid, and the content of harmful elements to be monitored is determined by ICP-MS after appropriate dilution; each standard substance digestion solution is diluted to a major element concentration of 1000μg / mL, and used to dilute the harmful element standard stock solution to obtain standard solutions with different concentration gradients; then the process blank and digestion sample are tested using an inductively coupled plasma mass spectrometer using a combination of internal standard method and matrix matching to obtain the content of trace harmful elements to be measured. It effectively overcomes the mass spectrometry and non-mass spectrometry interference problems faced by complex matrix sample testing, is suitable for the analysis and testing of trace element content in complex samples, and has a simple method and is easy to operate.

The invention discloses a preparation method of a cooling capacity trap system based on an MICP technology, and belongs to the technical field of cooling capacity storage. The method comprises the following steps: preparing a microbial solution, injecting the microbial solution into a target position by adopting a pulse injection mode, and applying a 5-10V direct-current electric field to the target position in the injection process; the microorganisms catalyze to generate calcium carbonate to fill pores and cracks of a target position to form a trapped layer. According to the device, pulse injection is adopted, the distribution uniformity of microorganisms is improved, the migration capacity of the microorganisms is improved through guidance of a low-voltage electric field during injection, uniform distribution of the microorganisms in a low-permeability medium (such as clay) is achieved, and the uniformity of a deposition layer is improved.

The invention relates to the technical field of mass spectrometers, in particular to an intelligent function optimization method for an inductively coupled plasma mass spectrometer, which comprises the following steps: S1, multi-parameter real-time monitoring: acquiring plasma torch temperature, ion lens voltage and mass spectrum detector noise parameters in real time through an embedded sensor array; s2, intelligent control adjustment: dynamically adjusting the power of a radio frequency generator and the carrier gas flow by adopting a self-adaptive fuzzy PID controller; s3, stability prediction modeling: establishing a plasma stability prediction model based on a deep belief network DBN, and outputting optimization parameters according to real-time acquired data; s4, virtual verification optimization: simulating the influence of parameter adjustment on mass spectrum resolution through a digital twin system; through multi-sensor monitoring, self-adaptive control and digital twinborn verification, the analysis precision and stability are remarkably improved, the matrix interference problem is effectively solved through the intelligent pretreatment technology, reliable operation of equipment is guaranteed through a three-level emergency mechanism, and manual intervention and maintenance cost are greatly reduced.

A carbon dioxide (CO2) hydrogenation catalyst and a method of its preparation. The CO2 hydrogenation catalyst includes an alkali-metal enriched bauxite residue including calcium carbonate (CaCO3), iron(III) oxide (Fe2O3), iron(III) oxyhydroxide (FeO(OH)), aluminum hydroxide (Al(OH)3), sodalite, muscovite, and Na5Al2CSi3O15. The CO2 hydrogenation catalyst further includes 1 weight percent (wt. %) to 10 wt. % potassium based on a total weight of the CO2 hydrogenation catalyst by inductively coupled plasma optical emission spectroscopy (ICP-OES). The CO2 hydrogenation catalyst is used in a method of hydrogenating carbon dioxide to produce olefins.

The utility model discloses an inductively coupled plasma mass spectrum exhaust butt joint pipe, which belongs to the technical field of plasma mass spectrum exhaust and comprises a waste gas exhaust pipe and a gas guide pipe, a lower connecting sleeve is sleeved on the outer side of the waste gas exhaust pipe, and an upper connecting sleeve is sleeved on the outer side of the gas guide pipe. According to the utility model, the lower connecting sleeve and the upper connecting sleeve are respectively sleeved on the outer sides of the waste gas discharge pipe and the gas guide pipe, and the annular air bags on the inner sides of the lower connecting sleeve and the upper connecting sleeve are inflated from the switch valve and the gas injection pipe through the external gas pump; the waste gas exhaust pipe and the lower connecting sleeve as well as the gas guide pipe and the upper connecting sleeve are sealed through expansion of the annular air bag, so that the waste gas exhaust pipe and the gas guide pipe are connected through the lower connecting sleeve, the telescopic air guide pipe and the upper connecting sleeve, and the situation that an inserting groove is formed in the exhaust pipeline for connection is avoided; and the practicability of the inductively coupled plasma mass spectrum exhaust butt joint pipe is improved.

A non-contact plasma monitoring method and a non-contact plasma monitoring device using same are disclosed. The non-contact plasma monitoring method may comprise: a first step of arranging one or more RF sensors on the outside of an inductively coupled plasma generator including an antenna, and measuring, as a function of time, induced electromotive force induced to each of the RF sensors by means of the antenna; a second step of performing the Fourier transform on the function of induced electromotive force at individual times, and then deriving the amplitude value of each of n-th harmonics; and a third step of deriving the state of plasma within the plasma generator from the amplitude values of each of the n-th harmonics.

The invention relates to the technical field of mass spectrometers, and discloses an analytical instrument based on glow discharge and quadrupole mass spectrometry combination, which comprises an ion source, an ion transmission system and an ion separator, wherein the ion source is a glow discharge ion source; the ion separator is a quadrupole rod mass analyzer, and the quadrupole rod mass analyzer comprises four electrodes which are arranged in parallel. Compared with an existing analytical instrument, the glow discharge ion source can directly analyze a solid sample without being pretreated into a solution, and compared with an inductively coupled plasma source, the glow discharge ion source is small in matrix effect and especially suitable for high-salt and high-carbon samples; the quadrupole rod mass analyzer is simple in structure, small in size, low in cost, especially suitable for commercialized popularization and high in scanning speed.

A method for processing a substrate is provided. The method includes disposing a substrate in a processing region of a process chamber and flowing a reaction gas into a remote plasma region of the process chamber, flowing a precursor gas into the processing region through the second plurality of channels in the showerhead, generating an inductively coupled plasma in the remote plasma region using the reaction gas to form plasma radicals, and exposing the precursor gas in the processing region to plasma radicals to form a dielectric film on the substrate with at least 95% step coverage.

A high-speed rail pantograph carbon contact strip abrasion detection method comprises the steps that carbon contact strip point cloud profile data of a high-speed rail pantograph are obtained through a single-line laser sensor; processing the data by adopting a motion blur correction algorithm based on spatial range screening and reflection intensity screening to obtain effective point cloud data; statistical filtering is carried out on the effective point cloud data, then normalization processing is carried out, and normalized effective point cloud data are obtained; obtaining a first demarcation point and a second demarcation point of the pantograph horn and the carbon contact strip by adopting a reflection characteristic identification method and a characteristic point identification method respectively; screening and integrating to obtain a final demarcation point, and intercepting to obtain an actually measured carbon slide plate point cloud data set; and comparing and registering the actually measured point cloud data set of the carbon contact strip and the point cloud data set of the standard carbon contact strip by adopting a point-to-surface ICP (Inductively Coupled Plasma) registration method so as to calculate the abrasion value and the over-limit abrasion area of the pantograph carbon contact strip. According to the invention, high-efficiency and high-precision detection of high-speed railway pantograph carbon contact strip abrasion can be realized.

This invention provides a high-selectivity dry etching method for surface convergence before p-GaN regrowth, comprising: etching the surface of the p-GaN layer or GaN layer of a GaN / AlGaN heterojunction in a Cl-based gas atmosphere to remove the native oxide layer and contaminants; introducing a mixture of BCl3 and fluorine-containing gas into a reaction chamber under inductively coupled plasma conditions, and maintaining the self-bias voltage within a first preset range for etching to selectively remove the p-GaN layer or GaN layer and achieve near-stop etching in the AlGaN layer, wherein the fluorine-containing gas is used to form an aluminum fluoride layer on the surface of the AlGaN layer to inhibit etching; and reducing the self-bias voltage from the first preset range to a second preset range and / or reducing the proportion of fluorine-containing gas in the mixed gas under plasma conditions to perform convergence treatment on the surface of the near-stop etched structure. This improves the repeatability of the process window and the adaptability of the regeneration length.

The invention discloses a multi-element quantitative analysis method for laser ablation inductively coupled plasma mass spectrometry, and aims to solve the problems that the quantitative process of the existing LA-ICP-MS technology depends on a standard sample, the automation degree is low, and the existing LA-ICP-MS technology cannot adapt to complex multi-element signals. According to the method, full-automatic and multi-element (such as 9 main quantities and 30 trace elements) quantitative analysis is realized in the LA-ICP-MS field without an internal standard and an external standard, the analysis efficiency, the accuracy and the data comparability among different platforms are remarkably improved, and a breakthrough solution is particularly provided for application of element quantitative imaging and the like.

The present invention relates to a method for preparing silicon monoxide nanopowder, and belongs to the technical field of non-metallic powder material preparation. The present invention uses SiO2 aerogel powder with a three-dimensional continuous structure surface as raw material, adsorbs hydrogen molecules on the surface of the powdered SiO2 aerogel, and axially feeds an argon-excited inductively coupled plasma torch. The hydrogen molecules are excited by the argon plasma torch to form a highly active hydrogen-rich plasma, which undergoes a reduction reaction with the SiO2 aerogel powder having the characteristics of high specific surface area and high porosity. The generated silicon monoxide vapor is quenched by argon downstream of the reaction device to obtain highly dispersible silicon monoxide nanopowder. This method overcomes the defects of the traditional solid-solid reaction method for preparing silicon monoxide, which has a slow reaction rate and low raw material conversion rate, and at the same time solves the safety problems existing in the traditional method of producing silicon monoxide by hydrogen reduction, thereby greatly improving production efficiency and safety.

The invention relates to the technical field of analysis and detection, in particular to a method for analyzing an aluminum element in peanut iodized oil. The analysis method specifically comprises the following steps: sample pretreatment: fully reacting a to-be-detected sample with nitric acid, treating the to-be-detected sample in a water bath environment at 80-120 DEG C for 1-2 hours, and then carrying out microwave digestion; after the digestion is completed, treating in a water bath environment at 60-80 DEG C for 1-2 hours, and fixing the volume. Performing inductively coupled plasma mass spectrometry determination: respectively adding internal standard ISTD elements with the same concentration into the standard solution, the test solution and the blank solution, and performing determination; and preparing a standard curve by using the standard solution, and calculating the concentration of the aluminum element in the test solution by using the standard curve. Compared with the prior art, the analysis method provided by the invention not only has lower requirements on the sample dosage, but also has higher accuracy and lower detection limit.

A flow control device for aerosolised sample delivery in an inductively coupled plasma (ICP) analytical system is provided. The device includes a body that at least in part defines a sample flow separating region, the sample flow separating region having a longitudinal flow direction and having an upstream end through which the aerosolised sample enters and a downstream end through which a modified aerosolised sample exits. The body further includes an injection duct having an opening adjacent to the sample flow separating region, the injection duct configured to direct a stream of gas in an injection direction to the sample flow separating region. The injection direction is angled relative to the longitudinal flow direction such that, upon introduction of the stream of gas through the opening, a vortex flow is generated in the sample flow separating region, the vortex flow having a direction counter to the direction of flow of the aerosolised sample to provide control of droplet size in the modified aerosolised sample.

This invention relates to a GaN-based pn junction diode device with a polarized beveled termination structure and its fabrication method. The device includes a cathode, a GaN substrate, an epitaxial layer, and an anode. The epitaxial layer comprises a lightly doped n-type GaN layer, an intrinsic GaN layer, and a p-type doped GaN layer grown in a single epitaxial growth process. The anode ohmic contact metal is placed on the p-type doped GaN layer, and the cathode ohmic contact metal is placed on the back side of the GaN substrate. It also includes a polarized beveled termination structure formed at the interface containing the pn junction, using inductively coupled plasma reactive ion etching (ICP-R) and a photoresist mask. The photoresist mask is formed using thick photoresist, followed by high-temperature heating and annealing to form the reflow morphology of the photoresist. Finally, wet repair and a passivation layer are applied to suppress the beveled n-type donor surface states of the polarized beveled termination structure. This invention effectively alleviates the boundary electric field concentration problem of GaN-based pn junctions and improves the breakdown voltage of GaN-based pn junctions.

The invention discloses a method for detecting various arsenic forms in an environment through inductively coupled plasma mass spectrometry. The method comprises the following steps: collecting air in the environment, continuously pressurizing the air, and storing the air in a collecting gas tank as a gas sample for later use; introducing the collected gas sample into a reaction kettle filled with a hydrochloric acid solution, mixing, conveying to a first spiral homogeneous conveying device through a first conveying pump, and then conveying to a cyclone spraying chamber; conveying the reaction kettle filled with the sodium borohydride solution to a second spiral homogeneous conveying device through a second conveying pump, and then conveying the sodium borohydride solution to a cyclone spraying chamber; argon is introduced into the cyclone spray chamber, and the cyclone spray chamber is connected with an inductively coupled plasma mass spectrometer and connected with a third delivery pump to discharge wastewater to a wastewater tank; gaseous hydride generated by the cyclone spray chamber and argon are conveyed to an inductively coupled plasma mass spectrometer for quantitative analysis. The technical effect of the invention is that the arsenic content and existence form in the environment can be better and more accurately detected.