A system includes a first laser beam including a pulsed laser emanating from the instrument propagates in the air, wherein the first lase beam is tuned to the wavelength at which a target chemical absorbs, its pulses bringing molecules to an excited state, a second laser beam used to probe target chemicals by transient absorption spectroscopy, wherein the second laser beam is pulsed or continuous, and a detector.

A high-sensitivity nanosecond to millisecond transient absorption spectrometer for measurements of miniscule signals under low excitation intensities includes an excitation source generating a frequency greater than 100 Hz, pulsewidth less than 5 ns excitation pulse for exciting a light absorbing sample, a probe light source for generating a photon flux probe light beam producing an average irradiance greater than 1 μW m.sup.−2 nm.sup.−1 for measuring the transient absorption spectrum of the sample before and after excitation by the excitation source, a DC-coupled detector capable of measuring light for enabling synchronous measurement of both the transmission of the probe light beam and the change in transmission of the probe light beam between a signal with the excitation pulse present and a signal in the absence of the excitation pulse, and a digital oscilloscope with a trigger rearm time capable of collecting every trigger event at high frequencies including 1 MHz, for enabling sequential noise subtraction protocols.

A method for preparing an intermediate by a reduced glutathione-indicated amino acid Maillard reaction is provided. The method includes a two-stage reaction at an increased temperature. A reduced glutathione is added after different times of a low-temperature reaction, and a subsequent Maillard reaction is effectively inhibited on a basis wherein a substance is interacted with an intermediate degradation product to reduce a formation of colored substances. Comparing with a browning of Maillard products after a high-temperature stage, a reaction time with a best color inhibition effect is found to be the optimal preparation condition of the intermediate, and the intermediate is prepared in an aqueous medium at a low temperature under this optimal preparation condition. The method uses the water soluble reduced glutathione as a tracer to improve a tracing accuracy comparing to cysteine.

A system for monitoring vibrations in a target region of interest may include a pulsed laser transmitter assembly, interferometric, telescope, and receiver optics, a photo-EMF detector assembly, signal conditioning/processing electronics, and a monitoring circuit/display. The detector assembly, which has a photo-EMF detector and amplifier circuits, generates an output signal indicative of the vibrations. A laser module outputs a source beam at a PRF of at least 2 Hz. A beam splitter device splits the source beam into separate interrogating and reference beams. The mirror directs the reference beam onto the photo-EMF detector for interference with a reflected return signal. The telescope optics generates an amplified return signal, and directs the amplified return signal to the photo-emf detector. The monitoring computer compares the output signal from the signal processor to a baseline to ascertain a difference therebetween, and generates a diagnostic signal indicative of the difference.

The invention relates to a device and a method for determining a wavelength of radiation.

The invention relates to a device for conducting radiation, a photodetector arrangement, and a method for spatially resolved spectral analysis.

A gas sensor comprising: a substrate; a grating array disposed on top of the substrate and comprising grates; and voids defined by the grates and configured to confine gas molecules for absorption of light and analysis. A method of gas sensing comprising: generating first light; converting the first light into second light using grates of a grating array; resonating the second light within the grating array; confining gas molecules in voids defined by the grates; and causing the gas molecules to absorb the second light within the voids.

A method for chemical identification of a sample having nanostructures includes the steps of irradiating the surface at wavelengths for each of a first and a second of the nanostructures that are uniquely absorbed by each of the first nanostructure and the second nanostructure such that each is excited to modulate at a first or a second nanostructure frequency, respectively. The method continues with the steps of irradiating the surface with electron beams incident on each of the first and second nanostructure, wherein at least one of secondary electrons, backscattered electrons and transmitted electrons are modulated at the frequency corresponding to each of the first and second nanostructure frequencies. A chemical map of the sample at an atomic scale is then created. A microscope is provided to carry out the method.

A system includes a first laser beam including a pulsed laser emanating from the instrument propagates in the air, wherein the first lase beam is tuned to the wavelength at which a target chemical absorbs, its pulses bringing molecules to an excited state, a second laser beam used to probe target chemicals by transient absorption spectroscopy, wherein the second laser beam is pulsed or continuous, and a detector.

A method of detecting an amine-based shale inhibitor in a wellbore servicing fluid (WSF) comprising contacting an aliquot of the WSF with an amine detector compound to form a detection solution; wherein the WSF comprises the amine-based shale inhibitor; and wherein the detection solution is characterized by at least one absorption peak wavelength in the range of from about 380 nm to about 760 nm; detecting an absorption intensity for the detection solution at a wavelength within about +20% of the at least one absorption peak wavelength; comparing the absorption intensity of the detection solution at the wavelength within about +20% of the at least one absorption peak wavelength with a target absorption intensity of the amine-based shale inhibitor to determine the amount of amine-based shale inhibitor in the WSF; and comparing the amount of amine-based shale inhibitor in the WSF with a target amount of the amine-based shale inhibitor.