95results about How to "Sharp peak" patented technology

The present invention provides quantitation of seven classes of compounds (saturates, 1-4+ ring aromatics, sulfides, and polars) present in petroleum streams boiling from 550-1050° F. Operating the present invention in the preparative mode will allow us to load and collect multi-milligram amounts of material. In the present invention, all seven fractions are produced in a single run, whereas the most commonly used preparative liquid chromatographic separations requires two or more large scale separations to generate similar fractions. The present invention uses 100 times less solvent. The present invention protocol provides a quicker and cheaper alternative to most commonly used preparative liquid chromatographic separations and is flexible enough to target many refining and chemicals problems.

Large-mode-area single material holey fiber tapers with collapsed by nonadiabatic process air holes in the waist for fiber optic sensors and a method for manufacturing these tapers are claimed. The gradual collapsing of the holes is achieved by tapering the fibers with a “slow-and-hot” method. This nonadiabatic process makes the fundamental mode of the holey fiber to couple to multiple modes of the solid taper waist. Owing to the beating between the modes, the transmission spectra of the tapered single material holey fibers exhibit several interference peaks. That means the all-fiber Mach-Zehnder type interferometer is formed in a holey fiber such a way. The multiple peaks, combined with a fitting algorithm, allow high-accuracy refractometric measurements, temperature-independent strain measurements, measurements of high temperature and may be used for measuring many others parameters.

A vanadium sodium phosphate positive electrode material, a sodium ion battery, and a preparation method therefor and application thereof. The preparation method of the vanadium sodium phosphate positive electrode material comprises the following steps: (1) reacting an aqueous solution containing a vanadium source with a phosphorus source, a reducing agent, a sodium source, and a carbon source, the reaction comprising first performing a reaction of an aqueous solution of the vanadium source and the phosphorus source, and then perform a reaction with the reducing agent, or first performing a reaction of the aqueous solution of the vanadium source with the reducing agent and then performing a reaction with the phosphorus source; (2) drying and calcining the reaction liquid obtained in step (1). The vanadium sodium phosphate positive electrode material has a high dispersibility, and has stable circulation performance when used in a battery.

The invention discloses an acoustic vector array wideband direction finding method based on a sparse decomposition theory, and relates to a direction finding technique and implementation method for target broadband continuous spectrum noise in the acoustic vector sensor array detection field. The sparsification idea is introduced to an acoustic vector array direction finding system; a combined sparse constraint is established according to frequency point components in broadband continuous spectrum noise signal bandwidth; and finally, a unified airspace sparse decomposition form is obtained, thereby realizing direction finding of the broadband continuous spectrum noise. According to the method, a relatively-sharp spectrum peak and a low-amplitude noise floor can be formed; when the number of array snapshots is small, the method is stable in performance and can distinguish coherent signal sources; and when the target DOA (direction of arrival) approaches to the array axial direction, the phenomenon of noise floor fluctuations occurring under the condition of low signal-to-noise ratio of a conventional beam forming (CBF) method and a minimum variance distortionless response (MVDR) method does not exist.

The invention relates to an amphiphilic aza-BODIPY fluorescent dye and a preparation method thereof. The preparation method comprises the following steps: reacting p-propynyloxy acetophenone with dodecyloxy phenylacetaldehyde to obtain chalcone; performing nitromethane nitration to obtain 4'-propynyloxy-4-dodecyloxy-2-nitromethylene-chalcone; carrying out coupling under an ammonium acetate condition, reacting the coupling product with boron trifluoride-ether to obtain an aza-BODIPY structure; and introducing different hydrophilic groups into the opposite alkynes of benzene with substituted 3rd and 5th positions of the parent structure of aza-BODIPY through click reactions so as to obtain the amphiphilic molecule. The provided synthesis method has the advantages of few steps, simple conditions, and high yield. Prominent aggregation phenomenon of amphiphilic BODIPY dye in water can be observed, the UV absorption of the dye is near 800 nm, the UV absorption peak is sharp, and the strength is extremely high.

The invention belongs to the field of pharmaceutical analysis and specifically relates to a method for detecting impurity phenylhydrazine in edaravone. The invention aims to provide a conveniently operated, quick and accurate method for detecting the phenylhydrazine. The method comprises the following steps of: controlling a key HPLC (High Performance Liquid Chromatography) detecting condition by adopting liquid chromatogram detection, wherein for a moving phase, a volume percent of acetate buffer solution to carbinol is (70%-90%):(10%-30%) or the volume percent of acetate buffer solution to acetonitrile is (70%-90%):(10%-30%); the concentration of the acetate buffer solution is 0.04-0.06mol/L and pH value is 6.4-6.8; the detection wavelength is 226-238nm; the flow speed is 0.6-1.2ml/min; and the column temperature is 10-35 DEG C. The key detection parameters are controlled, so that the convenient, quick and accurate detecting purpose is achieved. The method provided by the invention has the advantages of convenience for operation accuracy and reliability in detecting result, stronger specificity, and shorter detection time because the main peak retention time is 9 minutes, and provides a brand new choice for detecting the impurity and controlling the product quality.

The invention discloses an elemental analysis determination method and device. The elemental analysis determination method comprises the following steps: adding an inorganic compound capable of releasing hydrogen in pyrolysis into a to-be-detected sample and mixing the inorganic compound with the sample uniformly; carrying out pyrolysis on the mixture at a certain temperature, enabling an element to form a volatile matter, and determining the volatile matter by an atom spectrogram, wherein the inorganic compound for releasing hydrogen in pyrolysis is sodium bisulfide, potassium hydrogen sulfide, ammonium sulfide, ammonia hydrogen sulfide, ammonium iodide, hydrogen sulfide or hydrogen iodide, and the weight of the added inorganic compound is 0.2-100 times the weight of the sample. According to the invention, an inorganic hydrogen release reagent and a curie point pyrolyser are used, and the advantages of low analysis cost, less interference, high element volatile matter formation speed, high sampling efficiency of to-be-detected elements and the like are realized, and the method is a rapid and accurate analysis method.

The invention provides a method for measuring isothiazolinone antibacterial finishing agents in textiles, and relates to the field of product quality analysis, and discloses a method for separating and detecting the five isothiazolinone antibacterial finishing agents. The following liquid phase chromatographic conditions are adopted, and according to the liquid phase chromatographic conditions, a chromatographic column is XR-ODS (2.2 microns), the inner diameter is 100 mm*3.0 mm, column temperature is 40 DEG C, column flow speed is 0.4ml/min, a diode array detector is adopted, and detection wavelengths are 277 nm and 283 nm. According to the gradient elution conditions, the volume ratio of methanol to water is 40 to 60 for 0.00 min; the volume ratio of methanol to water is 90 to 10 for 1.90 min; the volume ratio of methanol to water is 90 to 10 for 6.00 min; the volume ratio of methanol to water is 40 to 60 for 6.01 min; 9.00 min. The five isothiazolinone antibacterial finishing agents are separated, a good baseline separation effect can be achieved, and peak types are sharp and symmetric.

The invention relates to a method for measuring the content of menthol in electronic cigarette liquid. The method is characterized by comprising the steps of preparing a sample solution to be measured by an ultrasonic extracting method, configuring a standard working solution with six concentration gradients, performing analysis by a gas chromatograph matched with hydrogen flame ionized detector, and measuring the content of menthol by an internal standard method. The result shows that when the content of menthol is 0.001mg/mL to 0.1mg/mL, the linear relation is good, the limit of detection (LOD) is 0.0028 percent, the average recover rate of three scaled levels is 100.9 percent, and the average relative standard deviation (RSD) is 1.38 percent. The method is high in sensitivity and good in repeatability and recovery rate.

The invention discloses a symbol timing synchronization method of an OFDM system. With the method, problems that no single sharp timing offset estimation function peak value is provided in the prior art and too much time is spent in determining an ideal timing position can be solved. The method comprises the following steps: 1, generating a training sequence and inserting the training sequence in front of a load data packet; 2, calculating a timing offset estimation function value at an initial position time of a sliding window at a receiving terminal; 3, taking an average of timing offset estimation functions of M times before the time at any time; 4, determining a weighting coefficient of the timing offset estimation function average value; 5, calculating a dynamic threshold according to the obtained timing offset estimation function average value and weighting coefficient; and 6, comparing the timing offset estimation functions and the dynamic threshold until detecting an ideal timing position of the current load data packet; and carrying out the operation continuously according to the mechanism to obtain an ideal timing position of each subsequent data packet. Therefore, timing can be realized accurately in a low-signal-to-noise-ratio environment and the real-time performance is good.

The invention discloses a detecting method of a content of benzene-type compounds in a food contact material. N,N-dimethylacetamide is used as a solvent dissolving test piece, extraction solutions of14 kinds of benzene-type compounds are obtained, and then a headspace-gas chromatography-tandem mass spectrometry method is adopted to perform qualitative analysis and/or quantitative analysis on theextraction solutions. According to the detecting method of the content of the benzene-type compounds in the food contact material, ion monitoring is used for qualitative confirmation and quantitativedetermination, the precision of the detecting result is ensured, and the detecting sensitivity is improved; and a headspace method is adopted, directly test piece feeding analysis is carried out, theoperation is easy and rapid, and consumption of large-quantity of solvents and environmental pollution are avoided.

The invention relates to a preparation method of a CsPb1-xZnxBr3 perovskite quantum dot. The method comprises the following steps: 1, mixing a cesium source, a lead source and a zinc source in a three-neck flask; then injecting oleic acid (OA), oleylamine (OLA) and 1-octadecene (ODE), under the protection of nitrogen atmosphere, performing heating and magnetic stirring to fully react, after the reaction is finished, applying ice-water bath treatment, performing centrifugal washing to obtain CsPb1-xZnxBr3 perovskite quantum dots, and finally dispersing the quantum dots into n-hexane to be stored. The CsPb1-xZnxBr3 perovskite quantum dot prepared by adopting the method has the characteristics of high crystallization quality, high PL luminous intensity and high PL quantum yield up to 57%, andcan be applied to the fields of illumination, display, photovoltaics and the like.

The invention provides an optical fiber combined array and a grating lobe suppression method based on the same. The method includes the steps that 1, three sub-arrays of the optical combined array receive incident signals respectively, the optical fiber combined array comprises the three sub-arrays which are sequentially arrayed, all the sub-arrays are uniform and equal-interval linear arrays respectively, array element intervals inside all the sub-arrays are relatively prime, and the interval among the three sub-arrays is the half wave length of the received signals; 2, according to the incident signals received by all the sub-arrays, the relatively prime sub-arrays are used for conducting beam forming, and wave beam data output in each scanning direction is obtained; 3, by the utilization of the feature that the array element intervals of all the sub-arrays are relatively prime, wave beam domain information of the three sub-arrays is comprehensively processed, and a spatial spectrumafter grating lobe suppression and a target direction estimation result are obtained. Through the method, the reliability and accuracy of estimating a space target direction can be improved, and a higher resolution is obtained; compared with a traditional uniform area array, an equivalent aperture can be increased, the number of array elements can be decreased, and engineer practical value is high.

The invention provides a method for detecting organic chlorine compounds in leather. The method includes carrying out ultrasonic extraction by the aid of normal hexane-ethyl acetate mixed liquid; carrying out purification by the aid of solid-phase extraction columns; concentrating eluent to a defined volume, then separating the eluent by the aid of DB-1701 quartz capillary columns; carrying out analysis by the aid of gas chromatography-mass spectrometry combined instruments; carrying out qualitative treatment in full-scanning modes; carrying out quantification in selective ion modes. The method has the advantages that the linear ranges of the 19 organic chlorine compounds detected by the aid of the method are 10-1000 ng/mL, the correlation coefficients R2 are higher than or equal to 0.9981, the detection limit is 0.01-0.1 mg/kg, the recycling rate is 74.1%-116.4%, and the RSD (relative standard deviation) is lower than or equal to 7.3% (n=6); the method is simple, convenient, speedy, accurate, stable and reliable and is applicable to simultaneously detecting the 19 organic chlorine compounds in the leather, and detection requirements on various technical indexes can be met.

The invention discloses a method for rapidly measuring patulin in fruit jam and vegetable paste, comprising the following steps: weighing 2.00g of fruit jam and vegetable paste in a centrifuge tube, adding 0.5-3mL of water, shaking, adding 5mL of ethyl acetate-normal hexane solution (95+5, v/v), shaking, simultaneously adding 0.5-2g of sea sands, 4-8g of anhydrous sodium sulfate and 0.5-2g of sodium bicarbonate, shaking vigorously for 2min, and centrifuging for 3min; and weighing 4mL of supernate until ethyl acetate activates a carbon black columella, receipting eluent by a test tube in which glacial acetic acid is added, eluting by 3-7mL of ethyl acetate, and drying; dissolving 240 mu L of acetonitrile, pipetting 150 mu L of dissolution liquid into a sample bottle, adding 50 mu L of derivatization reagent, heating by microwave for 1-7min, cooling and then measuring by gas chromatography-mass spectrometry. The method is rapid, simple, sensitive, accurate, specific and durable in confirmation and quantification, and is widely applied to the measurement filed of patulin in fruit jam and vegetable paste.

The invention discloses a preparation method of an in-situ hydrophobic modified basic magnesium sulfate whisker. According to the preparation method, an alkaline solution is dropwise added into a magnesium sulfate solution, then fatty acid or fatty acid/alcohol is added to serve as an in-situ modifying agent to obtain emulsion, and after a hydrothermal reaction is conducted, the in-situ hydrophobic modified basic magnesium sulfate whisker is obtained. By conducting in-situ hydrophobic modification on the basic magnesium sulfate whisker, fatty acid substances such as oleic acid, stearic acid and palmitic acid are adopted to serve as the in-situ modifying agent, the basic magnesium sulfate whisker is directly modified in situ in the preparation process, thus the basic magnesium sulfate whisker has good hydrophobic performance, in the application process, the compatibility with a hydrophobic substrate can be reinforced, and the performance of a composite material is improved.

The invention relates to a method for preparing submicron basic magnesium sulfate whisker with magnesite and prepared products. The method is characterized by comprising steps of preparing magnesium oxide (obtained through calcining magnesite) into active magnesium oxide powder, then adding distilled water to prepare a magnesium oxide initial slurry with initial concentration of 0.25-1.25mol/kg, adding 1.0mol/dm<3> sulfuric acid aqueous solution and an additive-polyacrylamide to the initial slurry so as to obtain a base material, putting the base material into a high pressure reactor, heating up while stirring, preserving heat for 1.0-5.0 hours at constant temperature and constant pressure when the temperature in the reactor reaches 150-200DEG C, then stopping heating and stirring, air cooling to room temperature, and carrying out conventional treatment on the product to obtain the submicron basic magnesium sulfate whisker, wherein the draw ratio of the whisker is greater than 100, the average diameter is 100-300nm, and the content of single whisker is over 90%.

The invention belongs to the technical field of chlorine ion curing agents, and especially relates to a chlorine ion curing agent for reinforced concrete and a preparation method and applications thereof. The curing agent is metal dihydroxide with a layered structure, has a micro-nano level granular shape, and is prepared by compounding 50 to 80 parts by weight of CaFe-NO3LDHs and 20 to 50 parts by weight of CaFeAl-NO3LDHs. The prepared chlorine ion curing agent does not damage a cement based material, and can stably and efficiently adsorb chlorine ions in a simulated concrete hole solution. In a cement paste sample, which has been soaked in a sodium chloride solution (3.5%), the corrosive performance of chlorine ions is obviously reduced, the effect is excellent, and the provided chlorineion curing agent is efficient and stable.

The invention discloses a high performance liquid chromatography (HPLC) detection method of Rivaroxaban. The method comprises the following steps: a. preparing a test solution; b. preparing a reference solution; c. respectively detecting the test solution and the reference solution by adopting HPLC, wherein the detection conditions are as follow: the stationary phase of a chromatographic column is silica gel which is coated with amylose-tri ((S)-alpha-methyl phenyl carbamate) on the surface, the mobile phase of the chromatographic column is acetonitrile-water, the flow velocity is 0.5-1.5ml/ min, the column temperature is 10-40 DEG C, and the detection wave length is 200nm-300nm. After the detection method is used, the degree of separation of Rivaroxaban and Rivaroxaban R isomer is more than 3.0, and more theoretical plates are available, so that the detection result accuracy is effectively prevented from being influenced by the interference of all components; furthermore, the detection method has the advantages of being accurate and reliable in detection results, short in analysis time, low in cost, simple and convenient in operation, etc.

The invention discloses a curie-point pyrolyser of a volatile matter generated by an element in element determination. The curie-point pyrolyser adopts a liner tube and a curie-point pyrolysis crucible or curie-point foil filled with samples, with larger volumes than that of a pyrolysis chromatograph part. The pyrolyser comprises a heating coil 1, a quartz reaction liner tube 2, a reaction cavity 3, a reaction tube seal plug and sample support integrated device 4, a carrier gas inlet 5, a carrier gas outlet 6, the sample crucible or foil 7, a support 8 for carrying the sample crucible or foil, and a bracket 9 for carrying the support of the crucible or foil, wherein the bracket 9 for carrying the support of the crucible or foil and a seal plug are connected with a rod. Compared with a conventional tubular furnace pyrolyser, the curie-point pyrolyser has the advantages that heating velocity is high, the time of generating the volatile matter by the element is short, spectrum peak is sharp in element determination, environment temperature is low, operation is safe, and the like, and is beneficial to the accurate element determination.