62 results about "Background concentrations" patented technology

A system is described that is suitable for use in determining the location of leaks of gases having a background concentration. The system is a point-wise backscatter absorption gas measurement system that measures absorption and distance to each point of an image. The absorption measurement provides an indication of the total amount of a gas of interest, and the distance provides an estimate of the background concentration of gas. The distance is measured from the time-of-flight of laser pulse that is generated along with the absorption measurement light. The measurements are formated into an image of the presence of gas in excess of the background. Alternatively, an image of the scene is superimosed on the image of the gas to aid in locating leaks. By further modeling excess gas as a plume having a known concentration profile, the present system provides an estimate of the maximum concentration of the gas of interest.

The invention discloses a marine sniffing estimation method of sulphur content in fuel oil, comprising the following five steps: acquiring tail gas; drawing a SO2 monitoring curve and a CO2 monitoringcurve to acquire SO2 concentration value, CO2 concentration value, SO2 background concentration value and CO2 background concentration value during the same monitoring period; calculating sulphur content in marine fuel oil on the basis of material balance; acquiring monitoring time of ships with excessive sulphur content in fuel oil; and locking the ships with excessive sulphur content in fuel oil. By the marine sniffing estimation method of sulphur content in fuel oil, the purpose of identifying ships with illegal use of high sulphur oil can be achieved without going on board, and huge wastecaused by blind sampling is avoided. The invention provides an efficient means for accurate sampling inspection of ships in national ship emission control areas.

The invention discloses a PM 2.5 (particulate matter 2.5) sensor and an automatic calibration method thereof. By automatically calibrating detection results of a sensor through clean air, the error due to particulate matter accumulation is overcome and it is ensured that detection results of the sensor are highly accurate within a service cycle. A technical scheme of the invention refers to the PM 2.5 sensor, comprising a detection gas passage, a calibrating gas passage, a detection light source unit, a light receiving unit, a signal processing unit, an electromagnetic value, an electromagnetic valve unit and a detection chamber; by dividing a detection chamber intake passage into the detection gas passage and the calibrating gas passage and using outside air and filtered clean air respectively, PM 2.5 detection concentration and background concentration are obtained, thus enabling the detection centration to be calibrated with the background concentration.

The invention discloses a method for monitoring horizontal well staged fracturing effects by a micro-element tracer. The method mainly includes the steps: 1) selecting a micro-element with low background concentration as the tracer; 2) estimating the dosage of the tracer at each stage according to the dosage of fracturing fluid at each stage; 3) adding the tracers into a fracturing blender truck by a constant-flow pump through a ground low-pressure pipeline, and adding different tracers into different layer stages in fracturing; 4) performing cluster sampling on fracturing flow-back fluid after fracturing, detecting concentration of the tracer in the flow-back fluid, drawing a curve of the concentration of the tracer along with time variation, calculating water yield of each stage, analyzing fracture morphology after each stage is fractured, determining contribution of each stage to the water yield, and defining connectivity between a well bore and a well after fracturing. The method solves the problems that signal-to-noise ratio is low, reliability is poor, cost is high, radioactive contamination is generated, and the fracturing effects of each stage cannot be accurately evaluatedafter horizontal well staged fracturing is implemented.

The embodiment of the invention discloses an information source determination method comprising the steps that the time period to be analyzed is determined; the pollutant concentration information ofthe target monitoring point in the time period to be analyzed is acquired; the regional background concentration of each sampling moment obtained through the interpolation method within the time period to be analyzed is acquired; the local emission contribution observed by the target monitoring point is determined according to the pollutant concentration information and the difference value of theregional background concentration of each sampling moment within the time period to be analyzed; the two-dimensional wind vector information of the time period to be analyzed is acquired; and the location of the pollutant is determined according to the regional background concentration of each sampling moment within the time period to be analyzed, the local emission contribution and the two-dimensional wind vector information. The local emission concentration contribution and the regional transmission concentration contribution are combined with the wind speed, the wind direction and other parameters and then the corresponding vector diagram is drawn so that the real emission source and the location of the emission source can be analyzed by the method.

The invention provides a method for locating a buried gas pipeline leakage point based on tracer gas. The method comprises the steps that whether leakage exists in a gas pipeline or not is detected, and if the leakage exists in the gas pipeline, the following operations are carried out, that is, the location of the leakage pipeline is determined, holes are drilled in the determined leakage pipeline in the direction of gas flow, probe holes are labeled and counted, and the background concentration of H2 or He in the pipeline is measured; for a closed static gas pipeline, the following operations are carried out, that is, H2 or He tracer gas is injected into the closed static gas pipeline at a time, and tracer gas concentration is detected and recorded at predetermined intervals; and for a dynamic gas pipeline which does not stop conveying, the following operations are carried out, that is, the H2 or He tracer gas is injected into the dynamic gas pipeline continuously, the tracer gas concentration is continuously detected and recorded, and the location of the leakage point of the pipeline is determined based on the tracer gas concentration recorded in the closed static gas pipeline or the tracer gas concentration recorded in the dynamic gas pipeline.

The invention discloses a multifunctional water bloom growth and extinction experiment research system under influence of hydraulic engineering. The multifunctional water bloom growth and extinction experiment research system comprises a pretreatment system, a flowing water circulation experiment table, a flowing water control system and a monitoring analysis system, wherein the pretreatment system is used for providing algae containing experiment water with different background concentration for the flowing water circulation experiment table; the flowing water circulation experiment table is used for achieving an algae nondestructive growth environment under a smooth continuous water flow environment; the flowing water control system is used for simulating a flowrate variation process of the incoming flow of upstream and downstream hydraulic engineering of a channel reservoir by regulating water supply flow of a water supply channel according to scheduling working conditions of upstream and downstream hydraulic engineering set in the experiment; the monitoring analysis system comprises a water level sensor, a flow velocity meter, a flowmeter, a video sensor, a chlorophyll fluorescence and a computer. The multifunctional water bloom growth and extinction experiment research system can perform quantitative experiment research on complex hydrodynamic condition changes under influence of hydraulic engineering, algae growth changes under flowing water conditions, effect analysis and predication of water bloom inhibition through optical scheduling of upstream and downstream single or step hydraulic engineering, and the like.

The invention discloses a tracer agent monitoring technique method. The method comprises the following steps that A, a tracer agent is selected and the use level is designed, wherein the best tracer agent is selected mainly through five tests of an indoor background concentration test, a compatibility test, a static adsorption test, a liquidity test, and an interference test; B, tracer agent injection is conducted, the prepared tracer agent injection fluid is injected into a target layer section of a monitoring well by a tank car, cementing truck or constant-flow pump; C, the tracer agent is sampled, according to reservoir pattern conditions, monitoring purposes and industry standards, reasonable sampling time length and frequency are determined, strict sampling system requirements are established, sampling schemes are designed before and after profile control, after injection, sampling of surrounding oil well is carried out immediately by specialized sampling personnel; D, the traceragent is detected, and E, comprehensive analysis is conducted. Data obtained by the method is accurate. The method is simple and effective, and a major technological breakthrough is achieved.

The invention discloses an information obtaining method, which comprises the following steps of determining a time period to be analyzed and the preset time interval in the time period to be analyzed,wherein the time period to be analyzed comprises N preset time intervals; then, obtaining the contaminant concentration information set in each preset time interval; next, determining a target concentration value meeting the preset conditions in the contaminant concentration information set as the region background concentration, wherein the region background concentration is the target contaminant concentration value which is simultaneously observed from all monitoring units in the preset designated cell, is from the accumulated contaminants from the upwind direction on the units and is diffused into the cells through transmission; finally, determining the region background concentration in each preset time interval. The method and the device have the advantages that the information reflecting the region background concentration and the information reflecting the local discharge contribution can be distinguished; the discharge responsibility is strictly distinguished; the targeted improvement on atmospheric pollution can be facilitated.

An InAs/GaAs quantum dot light emitting diode and a method of fabricating the same are disclosed. The InAs/GaAs quantum dot light emitting diode which is formed by turning off an As shutter and using As background concentration for epitaxy, comprises a Si-doped GaAs substrate, a N-type structure, an undoped quantum well, aseries of quantum dot layers, spacer layers, a barrier layer and a P-type structure.

The invention discloses a device and a detection method for chromatography of CO, CH4 and CO2 ingredients in gas. The device and the detection method realize detection of a trace amount of CO, CH4 and CO2 in high-purity gas and detection of a trace amount of CO2 in other technical gas containing percent content of CH4 and a trace of CO2. Through cutting of a peak of CH4 of percent content, a small part of CH4 and CO2 is subjected to back-flushing secondary analysis so that a trace of CO2 is separated from CH4 of percent content and thus the problem that the spectral peak of the CH4 of percent content in the spectrogram covers the spectral peak of a trace of CO2 so that a trace of CO2 cannot be detected is solved. The device and the detection method develop an integral air passage application field, is not limited by only detection of a trace of an ingredient, can realize detection of a trace of an ingredient even if a background concentration is large and can be widely used for other air passages.

The invention relates to a sampling analysis method for an industrial factory district heavy metal pollution site. The sampling analysis method for the industrial factory heavy metal pollution site comprises the following four steps that 1, soil sampling is conducted on a factory district; 2, sample testing result statistics and space distribution analysis are conducted; 3, comparative analysis with background concentration is conducted; 4, correlation analysis is conducted, wherein when the Pearson coefficient of a Pearson relevance detection result of the concentration of a metal in soil of a specific site and the concentrations of other heavy metals of the specific site is larger than 0.05, the relevance between the concentration of the heavy metal and the concentrations of other heavy metals is poor, and it means that the soil of the site is polluted by the heavy metal. The sampling analysis method has the advantages that estimation is conducted from the four aspects of site land historical data analysis and site survey, sample concentration statistics and space distribution analysis, site target heavy metal background concentration comparison and heavy metal homologous analysis, and it is guaranteed that the evaluation result is higher in reliability.

The invention discloses a reflux closed-circuit and open-circuit dual-purpose wind tunnel. A power and fan section, a first diffusion section, a first reflux section, a stable and contraction section,a test section, a second diffusion section and a second reflux section are successively connected to form a closed circuit. Baffle units are arranged at joint corners on two sides of the first refluxsection. Baffle units are arranged at joint corners on two sides of the second reflux section. Valves are arranged on both ends of the second reflux section. The baffle units at two corners of the second reflux section are movable. When the valves on both ends of the second reflux section are simultaneously closed, the wind tunnel is in closed-circuit operation. When the valves on both ends of the second reflux section are simultaneously opened, the baffle units at two corners of the second reflux section move into the second reflux section, and the wind tunnel is in open-circuit operation. The drawback of constantly increasing simulation experiment error caused by constantly increasing background concentration of a tracer agent in closed-circuit operation is avoided.

The invention provides an artificial board VOC (Volatile Organic Compounds) releasing cabin capable of guaranteeing a limit value of a background gas concentration of a cabin body, relating to the artificial board VOC releasing cabin. The device solves the problems that the background concentration of the gas of the existing small-capacity releasing cabin cannot meet the requirement and an experimental result is influenced. A nitrogen gas inlet pipe is respectively communicated with a water container and a second flow meter; the water container is communicated with a first flow meter; the first flow meter and the second flow meter are communicated with a total flow meter; the total flow meter is communicated with a glass pipe; the glass pipe is communicated with the cabin body; a first water bath glass cover is arranged outside the cabin body; a motor is in a transmission connection with a speed reducing box; an output shaft of the speed reducing box is in the transmission connection with a tetrafluoroethylene shaft and a stainless steel fan; and a first electric heating rod and a first temperature and humidity sensor probe are electrically connected with a first temperature and humidity sensing controller. The artificial board VOC releasing cabin disclosed by the invention is used for detecting an artificial board and the releasing of volatile organic compounds VOC in a product.

The invention discloses a device for directly detecting non-methane hydrocarbon content. The device comprises a sample gas channel, two gas carrying channels, a sample loop, a chromatographic column,a multi-pass sample inlet valve, two gas storage pipes and a detector. In a load state, after sample gas is successively filled in the two gas storage pipes, non-methane hydrocarbon in the sample gasis eliminated through the chromatographic column for filling the sample loop, thereby finishing a quantitative sampling process. In this state, first carrying gas successively enters a first gas storage pipe, the sample loop and a second gas storage pipe and then enters the detector, thereby obtaining a non-methane hydrocarbon chromatographic peak with background gas as a baseline, and finishing direct detection for the non-methane hydrocarbon content. Second carrying gas performs backflush cleaning on the chromatographic column. The device and the method can realize direct detection for the non-methane hydrocarbon content in a one-time sample entering condition, and settles a problem of detected value error superposing caused by a subtraction method when the background concentration of the non-methane hydrocarbon in the sample is far lower than the methane concentration. Furthermore the device and the method have advantages of high detection result accuracy, reliable and stable method, etc.

The invention discloses a simple pretreatment room which comprises a cabin body. An air inlet used for inletting clean air of preset humidity and flow and an air outlet used for exhausting air are arranged in the cabin body. At least one semiconductor refrigeration plate capable of refrigeration and/or heating is arranged on the outer wall of the cabin body. A temperature and humidity sensor is arranged inside the cabin body. The semiconductor refrigeration plate and the temperature and humidity sensor are electrically connected with a controller respectively. A filter device is arranged inside the cabin body. According to the invention, the simple pretreatment room has the advantages of simple structure and low cost, and can provide a constant temperature and/or constant humidity clean cabin body with controllable temperature, relative humidity and background concentration; a stable standard test environment is provided for testing; the influence of environmental factors or other uncertainties on the pretreatment effect can be avoided; and pre-set constant temperature, humidity, background, wind speed, pressure and other pretreatment-required environment requirements can be met.

The invention discloses a ship tail gas signal automatic identification method suitable for a ship tail gas monitoring station. The method comprises the steps of defining a suitable meteorological condition of the ship tail gas monitoring station; automatically identifying an effective monitoring period; automatically calculating the background concentration of nitric oxide in the effective monitoring time period; and automatically identifying ship tail gas signals with nitric oxide concentration higher than air background concentration. According to the invention, through defining the effective monitoring range of the ship tail gas monitoring station, a series of automatic analysis is carried out on the measured monitoring data. The purpose of automatically identifying the ship tail gas signals can be achieved, the labor cost required for daily processing of a large amount of monitoring data and identification of the ship tail gas signals can be saved, the automation degree of operation of a ship tail gas monitoring station is improved, and the efficiency of ship tail gas monitoring and supervising in a ship emission control area is improved.

The invention discloses a gas emission determinator and a method for determining the trace nitrogen emission flux using the same. The gas emission determinator comprises an inner layer seal tank capable of being sealed, and an outer layer seal tank capable of being sealed, wherein the inner layer seal tank is arranged in the outer layer seal tank in a sleeving manner, and meanwhile is filled with an undisturbed soil column, and an inert gas buffer layer is arranged between the inner layer seal tank and the undisturbed soil column. The method for determining the trace nitrogen emission flux using the gas emission determinator comprises the following implementation steps: A, preparing undisturbed oil; B, replacing gas in a clearance between the inner layer seal tank and the undisturbed soil column; C, replacing gas between the inner layer seal tank and the outer layer seal tank; D, culturing; and E, determining the content of nitrogen in the inner layer seal tank, and calculating the undisturbed soil column nitrogen emission flux. The gas emission determinator and the method for determining the trace nitrogen emission flux using the same have the beneficial effects that the inert gas buffer layer positioned between the inner layer seal tank and the outer layer seal tank can be used for obviously reducing and even eliminating the nitrogen leakage, so that the trace nitrogen flux with high background concentration can be determined accurately.

The object of the present invention is to reduce the resistance for the n type InGaAs non-alloy layer. N type secondary collector layer (2), n type collector layer (3), p type base layer (4), n type emitter layer (5) and n type InGaAs non-alloy layer (10) are orderly formed on the semi-insulating GaAs substrate (1), the n type InGaAs non-alloy layer (10) is composed of a n type InGaAs gradual change layer (10a) having not homogeneous In composition (not homogeneous group layer) and a n type InGaAs homogeneous group layer (9) having homogeneous In composition. The n type InGaAs gradual change layer (10a) is composed of a first gradual change layer (7) (the first layer) with lower In composition and a second gradual layer (8) with higher In composition than that of the first layer. The first gradual layer (7) is adulterated with Si in order to restrain the background concentration of the C in the In composition and obtaining higher carrier concentration when adulterating Se as n type dopant.