51 results about "Visible spectrometry" patented technology

The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

The present invention provides an apparatus and method for high resolution spectroscopy using a narrow light beam source such as a superluminescent diode (SLD) and a tunable optical filter (TOF) for analyzing a formation fluid sample downhole and at the surface to determine formation fluid parameters. The SLD and TOF have a matching etendue. The analysis comprises determination of gas oil ratio, API gravity and various other fluid parameters which can be estimated after developing correlations to a training set of samples using a neural network or a chemometric equation.

A system and method for using near-infrared or short-wave infrared (SWIR) light sources for early detection and monitoring of breast cancer, as well as other kinds of cancers may detect decreases in lipid content and increases in collagen content, possibly with a shift in the collagen peak wavelengths and changes in spectral features associated with hemoglobin and water content as well. Wavelength ranges between 1000-1400 nm and 1600-1800 nm may permit relatively high penetration depths because they fall within local minima of water absorption, scattering loss decreases with increasing wavelength, and they have characteristic signatures corresponding to overtone and combination bands from chemical bonds of interest, such as hydrocarbons. Broadband light sources and detectors permit spectroscopy in transmission, reflection, and / or diffuse optical tomography. High signal-to-noise ratio may be achieved using a fiber-based super-continuum light source. Risk of pain or skin damage may be mitigated using surface cooling and focused infrared light.

A diffuse optical spectroscopic imaging (DOSI) apparatus for tissue spectroscopy measures absorption and scattering properties of tissue using multi-frequency frequency domain photon migration in a modular or networkable platform to provide full broadband information content. The apparatus includes: a broadband signal generator; a driver having an input coupled to the signal generator; a light source coupled to the driver, the light source for exposing the tissue to broadband modulated light at a plurality of wavelengths; an optical detector for receiving returned light from the tissue; an amplitude detection circuit communicated to the optical detector; a phase detection circuit communicated to the optical detector; and a plurality of filters and amplifiers, wherein the optical detector, amplitude detection circuit and phase detection circuit are interconnected with each other by corresponding ones of the plurality of filters and amplifiers to isolate signals and increase signal-to-noise ratio.

A system and method for non-invasive biomedical optical imaging and spectroscopy with low-level light is described. The technique includes a modulated light source coupled to tissue to introduce excitation light. Fluorescent light emitted in response to the excitation light is detected with a sensor. The AC intensity and phase of the excitation and detected fluorescent light is provided to a processor operatively coupled to the sensor. A processor employs the measured emission kinetics of excitation and fluorescent light to “map” the spatial variation of one or more fluorescence characteristics of the tissue and generate a corresponding image of the tissue via an output device. The fluorescence characteristic may be provided by exogenous contrast agents, endogenous fluorophores, or both. A technique to select or design an exogenous fluorescent contrast agent to improve image contrast is also disclosed.

Examples of a spectroscopy probe for performing measurements of Raman spectra, reflectance spectra and fluorescence spectra are disclosed. The integrated spectral probe can comprise one or more light sources to provide a white light illumination to generate reflectance spectra, an excitation light to generate an UV / visible fluorescence spectra and a narrow band NIR excitation to induce Raman spectra. The multiple modalities of spectral measurements can be performed within 2 seconds or less. Examples of methods of operating the integrated spectroscopy probe disclosed.

The present invention relates generally to the field of spectroscopy, and more particularly to tip-enhanced Raman spectroscopy that provides an enhanced contrast-ratio of a near-field Raman signal to a background signal. The near-field Raman signal is captured from a small volume of material near a metal-coated tip thereby achieving submicron lateral resolution.

Systems and techniques for improved spectroscopy. In some embodiments, mechanical and / or optical zoom mechanisms may be provided for monochromator systems. For example, movable detector systems allow a detector to be positioned with respect to a dispersive element in order to obtain a first resolution. The detector systems may then allow the detector to be positioned with respect to a dispersive element to obtain a second different resolution. In some embodiments, spectroscopy of a first sample region may be performed using a plurality of excitation wavelengths. Multiple detectors may be positioned to receive light associated with different ones of the plurality of excitation wavelengths.

The invention discloses a method for quickly determining the content of alpha-cellulose in dissolving pulp and particularly relates to a method for determining the content of alpha-cellulose in dissolving pulp by virtue of ultraviolet-visible spectrometry. The method comprises the following steps: (1) pre-treating a sample; (2) establishing a standard curve or a mathematical model; (3) detecting the sample by virtue of an ultraviolet / visible spectrophotometer; and (4) calculating to obtain a result. When used for determining the content of alpha-cellulose in dissolving pulp, the method has the beneficial effects that the operation is quick and simple, the detection result can be given within just one hour, and moreover, the result is objective and accurate.

The invention discloses a detection reagent kit for rapidly detecting poultry disease viruses and a detection method of the detection reagent kit and belongs to the field of spectroscopy and molecular diagnosis. According to the detection reagent kit and the detection method, silver sol prepared through a hydroxylamine hydrochloride complexation method is adopted as a Raman enhancement reagent; after the silver sol and an object to be detected are mixed evenly at a certain proportion, the mixture is dripped onto a quartz plate; after natural air drying, Raman detection is carried out with a SmartRaman Ocean5pro portable Raman spectrometer; after principal component analysis and linear discriminant analysis are carried out on an obtained Raman spectrum, qualitative detection of the target pathogen is achieved. The detection reagent kit is easy and convenient to operate and high in sensitivity and has broad application prospects.

The method shows how to violate predictions of quantum mechanics for matter. For light, the method has been disclosed in patent application Photon Violation Spectroscopy. The methods are different in specifying different methods for light and matter. For matter, the method typically uses the single 5.5 MeV alpha (He++) emitted from the radioisotope Americium-241 in spontaneous decay, a thin gold foil beam splitter, and two surface barrier alpha detectors. The detectors deliver a characteristic electrical pulse with amplitude proportional to matter wave energy. A circuit reads the coincidence rate and singles rates of pulses from the two detectors. Quantum mechanics predicts that the particle would go one way or the other at the beam splitter, and coincident detections of pulses characteristic of such a particle would occur only at an easily calculated chance rate. However, the method at hand shows such characteristic pulses occur in coincidence at a rate greatly exceeding chance. By exceeding chance the method demonstrates surpassing a binding energy threshold and predictions of quantum mechanics. The degree above chance is a new measure in fundamental physics and is usable as a material science probe of the beam splitter. An apparatus specially designed to test for the absence of true coincidences and then perform a beam splitting test to show split-beam coincidences becomes useful in applying the method of Particle Violation Spectroscopy to material science. Fundamental discoveries in physics have been made with this method; therefore it is a method of discovery in physics.

The invention discloses a method for analyzing tantalum-niobium ore through a low-dilution ratio fused X-ray fluorescence spectroscopy. The method comprises the following steps: firstly designing a standard curve, preparing and fusing a standard sample, then determining instrument analysis conditions, correcting a matrix and spectral line overlapping effect, establishing an analytical method to simulate the validity of a raw ore and concentrate sample verification method and determining niobium, tantalum, titanium, silicon, iron, manganese, calcium, aluminum, sodium, potassium and tungsten inthe niobium-tantalum ore. A low-dilution ratio fused sample preparation method is used as a method for pretreatment in X-ray fluorescence spectrology analysis of the tantalum-niobium ore, and on the premise of ensuring the method sensitivity, a particle size effect and a mineral effect are eliminated; besides, the sample decomposition problem is also solved, and the hydrolysis of the niobium and the tantalum in an acid solution is avoided; the low-dilution ratio fused X-ray fluorescence spectroscopy method is more time-saving and labor-saving than a traditional method when being used for analyzing major and minor components in the tantalum-niobium ore; and the method has the advantages of being low in detection limit, wide in linear range, high in analysis speed and the like.

The invention provides a method for detecting a corrosive and harmful gas in an insulating material of a dry type transformer, aiming to solve the problem that national standard issues a detection requirement on corrosive and harmful gas escape. The method is characterized in that an insulating material sample is extracted from a detected product, is crushed and put in a quartz tube of a tube type resistance furnace to be heated and oxygen is introduced in so as to generate acidic gas; two serially connected aspirator bottles filled with alkaline solution are connected to a gas outlet of the quartz tube to absorb the acidic gas; when the temperature rises to 1,000 DEG C, the heating is stopped; absorption solutions in the two aspirator bottles are collected, and deionized water is added into the mixture; and toxic substances is detected by adopting an ion chromatography-suppressed conductance detector and an ultraviolet-visible spectrometry spectrophotometry. The method provides reliable parameters for manufacturers to produce standard non-corrosive non-toxic green environmentally-friendly dry type transformers.

The invention discloses a novel vinegar age rapid detecting method, and belongs to the field of brewage raw material utilization and quality control. The method includes the steps of analyzing characteristic volatile gas of vinegar at different vinegar ages through a GC-MS, screening out a color-sensitive material sensitive to characteristic gas through the combination of an experimental method and an ultraviolet-visible spectrometry to prepare a color-sensitive sensor array, and finally inputting the difference value, analyzed by a computer, of the before-reaction color change gray scale and the after-reaction color change gray scale of the color-sensitive sensor array and a vinegar sample into a K nearest neighbor (KNN) model to judge the vinegar age of the vinegar. The vinegar age of the vinegar is detected by detecting the characteristic volatile gas of the vinegar at different vinegar ages through the color-sensitive material, and the method is a rapid, objective and low-price method; the method has great practical significance in meeting the requirement of costumers for food quality and safety and keeping the market order.

A method for analysing gas dissolved in power transformer oil based on Raman technique includes measuring out Raman spectrum generated by exciting various gas with laser, calibrating methematical relation of each gas characteristic spectrum line position and concentration to spectrum intensity to obtain Raman spectrum wavelength and intensity as wavelength being a set valve and intensity being changed direct ratio with changing of concentration confirming gas concentration by comparing Raman spectrum line chart with characteristic spectrum line.

The invention discloses a method for quickly and accurately determining the reactive property of dissolving pulp, and particularly relates to a method for determining the reactive property of the dissolving pulp by utilizing an attenuated total reflection and ultraviolet-visible spectrometry. The method comprises the steps of (1) carrying out sample alkalization and yellowing pretreatment; (2) establishing a chemometrics prediction model; (3) detecting a sample solution by adopting an attenuated total reflection-ultraviolet / visible spectrophotometer; (4) outputting a result. The method disclosed by the invention has the effects that the reactive property of the dissolving pulp is determined by adopting the method, the operation is quick and simple, the detecting result can be given out on the spot after a yellowing reaction is completed, and the result is objective and accurate.

Devices and methods for measuring the acidity of airborne matter are provided. A filter can be impregnated with an indicator dye which changes color in response to changes in acidity. After the sample passes through the filter, the filter can be analyzed using UV-visible spectrometry.

The invention relates to a thioureas ultraviolet probe and preparation and application thereof. A structural formula of the probe is as follows. The probe is obtained by reaction between phenyl isothiocyanate and hydrazine hydrate. The thioureas ultraviolet probe is used for detecting lead ions: preparing a probe solution, adding the probe solution into a lead ion solution to be detected, making the volume constant by utilizing a solvent, standing, detecting absorbance under the wavelength of 382nm by means of an ultraviolet-visible spectrometry, and determining the content of the lead ions in the lead ion solution to be detected according to a relationship between relative ultraviolet strength and lead ion concentration. The thioureas ultraviolet probe in the invention is solid powder which is convenient to use and store, and is obtained by direct reaction between the phenyl isothiocyanate and the hydrazine hydrate. A synthesis method is simple, the yield is high, the cost is low, and the application prospect is good.

The invention relates to a correction method for turbidity influence during water quality COD detection by using ultraviolet-visible spectroscopy. The correction method comprises the following steps of: firstly, acquiring absorption spectrum data of a to-be-detected water sample and a plurality of turbidity standard solutions, and solving a turbidity influence matrix, wherein the concentrations ofthe turbidity standard solutions correspond to the concentration of the water sample to be detected; calculating an observation matrix and a sparse basis matrix through utilizing a compressed sensingtheory to obtain a turbidity influence factor; solving an optimal solution through using a norm to reconstruct a turbidity absorption spectrum influence matrix; and finally, deducting the turbidity absorption spectrum influence from the absorption spectrum data of the to-be-detected water sample to obtain the COD absorption spectrum. According to the correction method, under the condition that the ultraviolet absorption properties of the ultraviolet-visible spectroscopy is not influenced, turbidity correction of the ultraviolet-visible absorption spectrum of an actual water sample can be effectively realized, turbidity influence is deducted, the COD absorption spectrum of a detection result and the correlation coefficient of the actual water sample reach 0.9941, the root-mean-square erroris 0.0098, and an effective new method is provided for accurately realizing accurate calculation of the COD of the water quality.

The present invention relates generally to the field of spectroscopy, and more particularly to tip-enhanced Raman spectroscopy that provides an enhanced contrast-ratio of a near-field Raman signal to a background signal. The near-field Raman signal is captured from a small volume of material near a metal-coated tip thereby achieving submicron lateral resolution.

A new method in microscopy is provided which extends the domain of AFM's to nanoscale spectroscopy. Molecular resonance of nanometer features can be detected and imaged purely by mechanical detection of the force gradient between the interaction of the optically driven molecular dipole / multipole and its mirror image in a Platinum coated scanning probe tip. The method is extendable to obtain nanoscale spectroscopic information ranging from infrared to UV and RF.

A system and a method for determining one or more distillation temperatures for one or more given distillation weight percentages of a crude oil sample are provided, which can be used to produce a simulated distillation curve. Simulated distillation temperatures of crude oil samples are assigned as a function of density and data derived from UV / Visible spectroscopy measurement of the crude oil samples.