1088 results about "Absorbance spectra" patented technology

A catheter based method and apparatus for reflectance generated absorption spectral analysis of chronic inflammatory vascular conditions such as seen with atherosclerotic plaque within a blood vessel or other body cavity or compartment. The use of a bright mid range infrared light (mid-IR) source yields detectable reflected optical signals that may be sampled from an area smaller or larger than the typical diameter of a mammalian cell. The mid-IR light is delivered at selected mid-infrared wavenumbers. Using the apparatus and methods, the reflectance spectra and reflectance generated absorption spectra of a target tissue can be compared to reference spectra to identify and distinguish normal epithelium from tissue containing physiological markers indicative of vascular disease or other inflammatory conditions.

A photoelectric conversion element comprises a first photoelectric conversion part, the first photoelectric conversion part comprising: a pair of electrodes; and a photoelectric conversion film between the pair of electrodes, wherein the photoelectric conversion film comprises an organic photoelectric conversion material having an absorption peak in an infrared region of an absorption spectrum within a combined range of a visible region and the infrared region and generating an electric charge according to light absorbed, and the first photoelectric conversion part as a whole transmits 50% or more of light in the visible region.

Techniques for providing spectroscopic imaging integrates an acousto-optic tunable filter (AOTF), or an interferometer, and a focal plane array detector. In operation, wavelength selectivity is provided by the AOTF or the interferometer. A focal plane array detector is used as the imaging detector in both cases. Operation within the ultraviolet, visible, near-infrared (NIR) spectral regions, and into the infrared spectral region, is achieved. The techniques can be used in absorption spectroscopy and emission spectroscopy. Spectroscopic images with a spectral resolution of a few nanometers and a spatial resolution of about a micron, are collected rapidly using the AOTF. Higher spectral resolution images are recorded at lower speeds using the interferometer. The AOTF technique uses entirely solid-state components and requires no moving parts. Alternatively, the interferometer technique employs either a step-scan interferometer or a continuously modulated interferometer.

A flow imaging system is used to implement surface plasmon resonance (SPR) detection to study bio-molecular interactions. The flow imaging system is used to capture SPR absorption spectra of large numbers of objects, where each object includes both a metal film capable of exhibiting SPR, and detecting molecules. Analyte molecules are added to a solution of such objects, and the result is introduced into the flow imaging system which collects full SPR spectral data from individual objects. The objects can be nanoparticles or larger particles that support metal island films. The SPR spectral data can be used to determine specificity, kinetics, affinity, and concentration with respect to the interactions between the detecting molecules and the analyte molecules.

A compact mid-IR laser device utilizes a quantum cascade laser to provide mid-IR frequencies suitable for use in molecular detection by signature absorption spectra. The compact nature of the device is obtained owing to an efficient heat transfer structure, the use of a small diameter aspheric lens and a monolithic assembly structure to hold the optical elements in a fixed position relative to one another. The compact housing size may be approximately 20 cm×20 cm×20 cm or less. Efficient heat transfer is achieved using a thermoelectric cooler TEC combined with a high thermal conductivity heat spreader onto which the quantum cascade laser is thermally coupled.

The invention discloses a multi-wavelength high-sensitivity online monitor of multi-component NH3 and H2O based on semiconductor laser absorption spectroscopy. It contains host chassis and open long-path system. Equip power receptacle, switch, fiber connector and data transmission interface. It is characterized in that: there are near-infrared semiconductor laser, semiconductor laser controller, phase-locked amplifier, signal generator, data collecting and controlling module and infrared detector in host chassis which is connected with field optical system by fiber. Open optical system contains send-receive optical telescope and multielement reflector array. Optical telescope has input and output fiber couplers. The device realizes simultaneous testing of gas multi-component by using multi-wavelength and frequency division multi-signal detecting technique.

A novel multivariate model for analysis of absorbance spectra allows for each wavelength or spectral region to be modeled with just enough factors to fully model the analytical signal without the incorporation of noise by using excess factors. Each wavelength or spectral region is modeled utilizing its own number of factors independently of other wavelengths or spectral regions. An iterative combinative PCR algorithm allows a different number of factors to be applied to different wavelengths. In an exemplary embodiment, a three-factor model is applied over a given spectral region. The residual of the three-factor model is calculated and used as the input for an additional five-factor model. Prior to the additional five factors being applied, some of the wavelengths are removed. This leads to a three-factor model over the first region and an eight-factor model over the second region. This analysis of residuals can be repeated such that a one to n factor model could be applied to any given wavelength, or rather any number of factors may be employed to model any given frequency or spectral region. A method of predicting concentration of a target analyte from sample spectra applies a calibration developed using the inventive PCR algorithm to a matrix of sample spectral to generate a vector of predicted concentrations for the target analyte.

The invention discloses a method for automatically monitoring water quality indexes on line and a device for implementing the method. A method of combining an ultraviolet and visible spectroscopy and various sensors is adopted, dozens of water quality indexes including chemical oxygen demand and ammonia nitrogen can be measured at one time, measurement indexes can be configured in a building block mode according to requirements, and chemical agents are not required. According to the device, the constructed digital optical fiber spectrometer is taken as a core, ultraviolet and visible absorption spectrum data of a water sample is processed in a mode of sequentially combining wavelet de-noising, principal component analysis and a support vector machine, and water quality indexes such as chemical oxygen demand and biochemical oxygen demand of water are acquired. Various physical and electrochemical sensors acquire water quality indexes such as ammonia nitrogen, dissolved oxygen and conductivity. All hardware and software for implementing the method is put in a cabinet to form the device, and the device analyzes the introduced water sample under the control of an embedded industrial control computer system, and automatically monitors the water quality indexes in real time.

A reimageable medium for receiving an imaging light having a predetermined wavelength scope, the medium composed of: a substrate; a photochromic material capable of reversibly converting among a number of different forms, wherein one form has an absorption spectrum that overlaps with the predetermined wavelength scope; and a light absorbing material exhibiting a light absorption band with an absorption peak, wherein the light absorption band overlaps with the absorption spectrum of the one form.

A fourth embodiment of the present invention is a method of generating a temperature compensated absorbance spectrum. The method includes the steps of: a. providing a sample spectrum and an estimated temperature of a backdrop object; b. from a set of known temperature spectra related to a known background temperature, selecting at least two known temperature spectra representing a background temperature above and below the estimated temperature; c. comparing the sample spectrum to the known temperature spectra in order to determine a sample background spectrum; and d. calculating an absorbance spectrum from the sample spectrum and the background spectrum.

There is provided a compound represented by a specific formula, which has an absorption maximum at 400 nm or more and less than 720 nm in a UV-visible absorption spectrum, wherein a molar extinction coefficient is 10,000 mol−1·l·cm−1 or more at the absorption maximum wavelength, and a difference between a melting point and a deposition temperature (a melting point−a deposition temperature) is 31° C. or more.

The invention discloses a low-concentration, multi-component and high-sensitivity gas detection method based on integration of multiple spectrum technologies. Advantages of an ultraviolet differential optical absorption spectroscopy (DOAS) technology and an infrared tunable diode laser absorption spectroscopy (IR-TDLAS) technology are integrated, so that information integration and characteristic signal extraction of two kinds of spectrum are realized. The method disclosed by the invention is used for measuring the NH3 concentration in smoke by utilizing a TDLAS method and simultaneously measuring the concentrations of SO2 and NO2 in smoke by utilizing an ultraviolet DOAS method; interference of three components in the NO absorbancy is removed according to the obtained concentrations and an interference spectrum of three kinds of gas to the NO absorbancy, so that the NO concentration without cross interference is solved; and thus, the measurement precision and the detection lower limit are greatly increased.

Methods are disclosed utilizing synchrotron X-ray microscopy including x-ray fluorescence and x-ray absorption spectra to probe elemental distribution and elemental speciation within a material, and particularly a solid that may have one or more elements distributed on a solid substrate. Representative materials are relatively homogeneous in composition on the macroscale but relatively heterogeneous on the microscale. The analysis of such materials, particularly on a macroscale at which their heterogeneous nature can be observed, provides valuable insights into the relationships or correlations between localized concentrations of elements and / or their species, and concentrations of other components of the materials. Sample preparation methods, involving the use of a reinforcing agent, which are advantageously used in such methods are also disclosed.

An electroluminescent device includes a light-emitting layer containing a host material and: (a) a compound of Formula (1): X1—Ar1—C(R1)═C(R2)—Ar2   (1) wherein: Ar1 represents a divalent aromatic group; Ar2 represents an aromatic group; X1 represents at least one electron-donating group; R1 and R2 independently represent hydrogen or a substituent; and (b) a light-emitting boron complex having an absorption spectrum that overlaps with the emission spectrum of compound (1). The device serves to improve luminance efficiency while maintaining good color purity.

A lipid bilayer with affinity to an analyte, which directly signals binding by a changes in the light absorption spectra. This novel assay means and method has special applications in the drug development and medical testing fields. Using a spectrometer, the system is easily automated, and a multiple well embodiment allows inexpensive screening and sequential testing. This invention also has applications in industry for feedstock and effluent monitoring.

The invention relates to a cavity enhanced absorption spectrum device and method for simultaneous measurement of trace gas concentration and aerosol extinction. The LED temperature is controlled by a semiconductor refrigeration chip to ensure the stability of light intensity output. High reflectivity mirrors at both ends of an optical cavity have the same curvature radius and reflectivity greater than 99.9%, and compose a stable optical resonator. Usually, cavity enhanced absorption spectrum measures the light intensity in the cavity with or without gas absorption and the variation curve of the high reflectivity mirrors' lens reflectivity along with the wavelength, and finally the concentration of absorption gas in the cavity can be obtained. The device and the method provided by the invention can realize simultaneous measurement of trace gas concentration and aerosol extinction. The actual measured total absorption coefficient is divided into two parts, one part is a trace gas absorption structure changing rapidly along with the wavelength, and the other part is gas scattering and aerosol extinction coefficient changing slowly along with the wavelength. Nonlinear least-square fitting is carried out on the measured total absorption coefficient to calculate the concentration of the to-be-measured trace gas, and finally the gas absorption structure and gas scattering are deducted from the total absorption coefficient so as to obtain the aerosol extinction coefficient.

According to the invention, there can be provided a non-aqueous electrolyte secondary cell whose capacity is hardly decreased even stored at high temperatures in a charged state.The non-aqueous electrolyte secondary cell uses an insulation adhesive tape composed of a base material and a glue material. And in an absorbance spectra of the glue material measured using an infrared spectrophotometer so that the maximum peak intensity is 5 to 20% in transmittance, when peak intensities for C—H stretching vibration of 3040 to 2835 cm−1 and C═O stretching vibration of 1870 to 1560 cm−1 are respectively defined as I(C—H) and I(C═O), a peak intensity ratio represented by I(C═O) / I(C—H) is 0.01 or less.

A portable system for the real time detection and measurement of one or several gases is a gaseous mixture is disclosed. Such systems can be applied to industrial domains in which gases are to be measured and particularly toxic, dangerous, or polluting gases are generated. The system uses absorption spectrometry of a gas from a gaseous medium of interest. The optical means is at least two laser diodes with matchable cavities to generate a first and second wavelength, a light beam mixer prism, a double refraction crystal rotating on a controlled table. The tuned beam causes the gas to be measured to fluoresce and emit a signal to an infrared radiation detector which can indicate the identity and magnitude of the gas being measured.

Provided is a cell concentration / purification device having a function of successively locating cells in a specific area of a microchannel, and a function of sequentially capturing cell images by use of light from a plurality of monochromatic light sources on an image basis, and performing comparative analysis of the cell images to recognize individual cells based on information on the shape of the cells and an absorption spectral distribution of the cells or inside of the cells, thereby selectively separating / purifying the cells.

The invention discloses a multicomponent gas concentration quantitative analysis method based on absorption spectrogram reconstruction, which comprises the following steps: preestimating the concentration of each component in analyzed gas and converting absorbance, and reconstructing the spectrogram according to a Lambert-Beer theorem; then constructing a hook-shaped loss function by taking the difference of the spectral lines of the reconstructed spectrogram and an actual spectrogram. Input takes zero as a boundary; when the input is less than zero, a function value decreases progressively, and the decrease amplitude is smaller; when the input is greater than zero, the function value increases progressively, and the increase amplitude is bigger. Then iteration operation is carried out on the concentration of each component in the gas to be analyzed by adopting a momentum method or a genetic algorithm until the concentration difference of each component in the iteration results of two adjacent times is less than a preset admissible value to end the iteration operation. The method has high analysis speed, accurate result and small influence of interference on an analysis result, can be used for gas logging, product quality check and fault diagnosis and the multicomponent gas quantitative analysis of the fields of hardware, chemical industry, environmental protection and the like.

A rapid diagnosis method for organ specific disease state is based on obtaining an infrared absorbance spectra of a patient's blood at a frequency range from about 400 cm<-1 >to about 2000 cm<-1 >and further from about 3000 cm<-1 >to about 3100 cm<-1>. Comparing it with the predetermined normal infrared absorbance spectra of known healthy subjects for the presence or absence of predetermined features such as increase or decrease of infrared absorbance, peaks at particular frequencies allows for accurate diagnosis of a disease of an organ, including most major organs such as a heart, lungs, stomach, liver, kidneys, brain, etc.

Cavity enhanced absorption spectroscopy systems and methods for detecting trace gases using a resonance optical cavity, which contains a gas mixture to be analyzed, and a laser coupled to the cavity by optical feedback. The cavity has any of a variety of configurations with two or more mirrors, including for example a linear cavity, a v-shaped cavity and a ring optical cavity. The cavity will have multiple cavity resonant modes, or a comb of frequencies spaced apart, as determined by the parameters of the cavity, including the length of the cavity, as is well known. Systems and methods herein also allow for optimization of the cavity modes excited during a scan and / or the repetition rate.

The present invention relates to a composite semipermeable membrane, which is useful as a reverse osmosis membrane or a nano-filtration membrane and comprises a polysulfone porous support membrane and a polyamide ultrathin layer formed on one of the surfaces of the porous support membrane, the composite membrane having the characteristic that in the infrared absorption spectrum obtained from the surface of a polyamide ultrathin layer of the composite semipermeable membrane, the ratio T (=Aa / As) of absorption intensity Aa at the absorption peak revealing C=O of polyamide in the region of 1600-1700 cm-1 to absorption intensity As at the absorption peak revealing polysulfone at a wavenumber around 1586 cm-1 is at least 0.05 and not higher than. The composite semipermeable membrane thus obtained can attain conversion of sea water into fresh water, desalination of brackish water, recovery of valuable matter in aqueous solutions, treatment of waste water, and particularly removal of impurities (e.g., organic substances) from water.

The invention discloses a dual-functional probe and a preparation method and application in detection of a G-quadruplex structure thereof. The probe is simple to prepare, readily available, and stable in structure, and can be used for the specific detection of G-quadruplex nucleic acid secondary structure, and fast detection of the secondary structure of a DNA sample in a solution according to an ultraviolet and visible absorption spectrum, a fluorescence spectrophotometer, or direct visual inspection of naked eyes. The method for detecting the G-quadruplex nucleic acid secondary structure by the probe has the advantages of simple and convenient operation, excellent and fast selectivity, and visibility by naked eyes, and overcomes the defects of high cost and equipment requirement, relatively complex technical operation and the like of other detection methods.