10results about How to "Sharp peak" patented technology

The invention belongs to the technical field of lithium ion battery materials, and particularly discloses an in-situ doped and coated lithium iron phosphate material as well as a preparation method and application thereof. The lithium iron phosphate material comprises an in-situ carbon coating layer and a lithium iron phosphate core doped with high-valence metal cations in situ, the chemical general formula of the lithium iron phosphate material is LiFe1-xMxPO4 (at) C, x is more than or equal to 0.003 and less than or equal to 0.007, and M comprises at least one of Nb, V, Ti or Y. The lithium iron phosphate material has the advantages of favorable crystallinity, favorable sphericity, uniform distribution of large and small particles, excellent electrochemical properties, high compaction density and low powder resistivity of the material powder, and has high specific discharge capacity and cycle capacity retention ratio when being used as the positive electrode material of the lithium ion battery. The invention also provides a preparation method and application of the lithium iron phosphate material.

The present invention discloses a thermal analyzer with low-temperature adsorption function, including an axial flow fan, a radiator, a heat preservation box, a refrigeration sheet, a cold storage sheet, a six-way valve, a driving motor, a carrier gas flow controller, a secondary adsorption tube, a primary adsorption tube, a primary heating body, a purge gas flow controller, a vent pipe, a detection device and a heating wire. The axial flow fan is provided with a radiator, and the axial flow fan is provided with a heat preservation box. The heat preservation box is provided with a refrigeration sheet and a cold storage sheet, and the cold storage sheet is provided on the refrigeration sheet. A thermal analyzer with low-temperature adsorption function is manufactured by adopting the above technical scheme. The secondary thermal analysis technology is adopted to make the peak shape sharper and improve the detection limit. Since the secondary analysis device has the advantages of small size, low-temperature concentration and rapid heating, the system error is reduced, the unit concentration is increased, and the detection limit is greatly improved.

This invention belongs to the field of gas sensor technology and discloses a method for preparing europium ferrite nanosensors and their applications. This method utilizes electrospinning technology combined with a specific low-temperature confined-domain calcination process (550℃~700℃) to prepare EuFeO3 nanotubes with a hollow structure and rough surface by taking advantage of the thermal decomposition kinetics differences of poly(p-v) magnets (PVP). This process effectively suppresses excessive repair of lattice oxygen while forming a unique tubular morphology, effectively "freezing" oxygen vacancies (O2) accounting for up to 34.44% on the material surface in situ. v This invention addresses the shortcomings of traditional solid fiber materials by constructing a sensor using a grinding, dispersion, and coating process. Utilizing the dual reactive surfaces of hollow nanotubes and high-concentration oxygen vacancy active sites, it achieves highly sensitive and selective detection of low-concentration ethylene gas released during fruit ripening. This invention solves the problems of small specific surface area and insufficient active sites in traditional solid fiber materials.

The application provides a fiber-optic Fabry-Perot sensor based on light beam convergence and a manufacturing method thereof, and relates to the technical field of semiconductors. The sensor comprises a diaphragm layer, an intermediate layer and a bottom layer which are arranged in layers; the diaphragm layer is provided with a first groove, the intermediate layer is attached to the diaphragm layer in a manner that a first layer surface thereof faces the first groove, so as to form a Fabry-Perot cavity based on the first groove; the bottom layer is provided with a second groove, the intermediate layer is attached to the bottom layer in a manner that a second layer surface thereof faces the second groove, so as to form a nano-containing cavity based on the second groove; the second layer surface of the intermediate layer is formed with a micro-nano anti-reflection structure comprising array-distributed anti-reflection units located in the nano-containing cavity; and the bottom layer is formed with a micro-nano collimation structure comprising array-distributed collimation units located in the nano-containing cavity and in a symmetrical positional relationship with the micro-nano anti-reflection structure. The application at least reduces the manufacturing complexity.

The invention provides a method for determining the content of methylhydrazine by pre-column derivatization-high performance liquid chromatography, which comprises the following steps: S1, uniformly mixing a methylhydrazine hydrate sample solution, 9-fluorenylmethoxycarbonyl chloride and an alkaline solution, standing for 20-50 minutes at room temperature to perform a derivatization reaction, and adding an acid solution to terminate the reaction; and S4, detecting the sample derived in the S1, establishing a chromatogram of methylhydrazine in the sample solution to be detected, obtaining a chromatogram retention time range of methylhydrazine, and calculating the content of methylhydrazine in the methylhydrazine hydrate according to the standard curve fitted in the S3. The pretreatment method is simple, the reaction condition is mild, the reaction rate is high, the detection sensitivity is high, the methylhydrazine derivative generated in a pre-column derivatization mode has ultraviolet absorption, a methylhydrazine derivative peak can be separated from a 9-fluorenylmethoxycarbonyl chloride chromatographic peak through reversed-phase high performance liquid chromatography, and detection of methylhydrazine is not interfered.

The present invention provides a gas phase determination method of dithiocyanomethane in aquatic products, and relates to the field of pesticide residue detection. The present invention aims to provide a gas chromatography (GC-PFPD) method for determining dithiocyanomethane in aquatic products, and to provide a simple, rapid and practical detection technology for monitoring dithiocyanomethane drug residues in aquatic products. The pretreatment method established in the present application is simple and easy to operate, and can enable stable and efficient recovery of MBT; the chromatographic conditions used in the present experiment make the peak shape of MBT sharp and symmetrical, without interference from impurity peaks. The method has high sensitivity, good repeatability and accuracy, and is suitable for residual analysis of dithiocyanomethane substances in aquatic products.

This application discloses a method for detecting the content of diamine compounds in tile grout. The method includes: mixing, diluting, and derivatizing diamine compound standards with solvents to obtain standard solutions of diamine derivatives at various concentrations; testing the standard solutions of diamine derivatives at various concentrations in a chromatograph and obtaining a standard working curve after fitting; mixing, diluting, and derivatizing a test sample containing the diamine compounds with a solvent to obtain a derivatized test sample solution; testing the derivatized test sample solution in a chromatograph to obtain the area of ​​the chromatographic peak of the diamine compounds, then obtaining the concentration of the diamine compounds, and finally obtaining the content of the diamine compounds in the test sample. According to the embodiments of this application, the content of multiple diamine compounds can be detected simultaneously and accurately.

The invention provides UPLC-MS (Ultra Performance Liquid Chromatography-Mass Spectrometry) chemical components of Zhuang medicine embelia parviflora and a fingerprint spectrum analysis method thereof, and belongs to the technical field of medicine analysis. The method comprises the following steps: step 1, setting detection conditions of a quadrupole electrostatic field orbitrap high-resolution mass spectrometry method; 2, setting fingerprint conditions; 3, chemical component identification result analysis; and 4, establishing the UPLC fingerprint chromatography of the embelia parviflora. According to the method, chemical components of embelia parviflora are analyzed by adopting a UPLC-Q-Exactive HRMS (High Resolution Mass Spectrometry-Quantitative Exactive High Resolution Mass Spectrometry) technology, and in consideration of serious interference of ion fragments, a spectrum library matching result can be seriously influenced, and the deduction of a mass spectrum splitting decomposition process can be interfered, so that only 10 components with the matching degree being greater than 85% are screened in an experiment, and the deduction of the mass spectrum splitting decomposition process is carried out.

This invention discloses a method for estimating the spatial power spectrum of a small-aperture linear array based on ellipsoidal semi-axis measurement, comprising: S1. acquiring a time-domain data matrix; S2. calculating a frequency-domain data matrix; S3. calculating a set of frequency indices; S4. decimating the frequency-domain data matrix; S5. determining a set of scanning directions; S6. calculating a time compensation vector; S7. calculating a phase compensation matrix; S8. performing phase compensation on the decimated frequency-domain data matrix; S9. constructing and solving a positive semi-definite programming problem; S10. calculating the ellipsoidal semi-axis measurement; and S11. calculating the spatial power spectrum based on the ellipsoidal semi-axis measurement. This method directly utilizes the frequency-domain data matrix to estimate the spatial power spectrum, eliminating the need to calculate the signal covariance matrix or perform eigenvalue decomposition. While reducing computational complexity, compared to traditional spatial power spectrum estimation methods based on conventional beamformers, it is more advantageous for estimating target directions when the number of array elements is small or the element spacing is much smaller than half the signal wavelength.

The invention belongs to an underground cable fault positioning method, and provides a traveling wave time delay estimation method and a related device in order to solve the problem that a traveling wave signal processing algorithm cannot completely meet high-precision and high-adaptability traveling wave time delay detection requirements in a complex electric power scene. Carrying out adaptive frequency band wavelet deconstruction and detail extraction on the first sensing signal and the second sensing signal respectively, and then carrying out dynamic parameter modal splitting based on variational problem solution on each reconstructed signal in the obtained multi-layer first reconstructed signal group and the second reconstructed signal group corresponding to the scale; the method comprises the following steps: obtaining a plurality of intrinsic frequency band modal components with specific sparsity, taking the first intrinsic frequency band modal component as a main mode, comprehensively considering the energy ratio and cross-correlation sharpness of two main modes in each layer, and determining a final traveling wave time delay estimation result according to the cross correlation coefficient of the two main modes under the optimal common decomposition layer. According to the method, the calculation redundancy is reduced while the precision is ensured, and the real-time performance is improved.