34 results about "Gamma gamma" patented technology

A downhole gamma ray density measurement system is described. The gamma ray density measurement system includes a pressure housing and a gamma ray source within the pressure housing. One or more detectors within the pressure housing detect gamma radiation. One or more low-attenuation inserts may be located in the pressure housing near the gamma ray source and / or one or more of the detectors. One or more high-attenuation inserts may be located in the pressure housing near the gamma ray source and / or one or more of the detectors.

The invention relates to a Gamma-Gamma distribution parameter estimation method based on a double logarithmic cumulant expectation, and belongs to the technical field of atmospheric turbulence channel parameter estimation of free space optical communication systems. According to the method, a Gamma-Gamma distribution parameter estimation process is simplified greatly through Mellin transform, and a uniform parameter estimation method is built specific to the problems of low fractional moment (FMOM) parameter estimation accuracy and even error estimation in the prior art. Then, further improvements are made, and a concept of double logarithmic cumulant expectation is put forward, so that a finial parameter estimation expression is deduced. Compared with an FMOM, the Gamma-Gamma distribution parameter estimation method has the advantages that relatively high computing efficiency is ensured, and the parameter estimation accuracy is increased.

A scintillator crystal (26) based gamma-ray camera system is described. The gamma-ray camera system includes a spectra processing component for (34) providing improved energy resolution over that seen in conventional gamma-ray camera systems. The spectra processing component operates to deconvolve detector response functions from observed energy spectra on a pixel by pixel basis. The pixel dependent to detector response functions are obtained by a combination of theoretical simulation, and empirical calibration. By deconvolving pixel specific detector response functions, variations in response of a gamma-ray camera system across its image plane can be accounted for. This offers significant improvements in energy resolution and many of the problems associated with conventional gamma-ray camera systems are reduced. For example, the improved energy resolution allows better rejection of photons associated with Compton scattering events occurring in a source being imaged. This is because a narrower energy window filter can be used without rejecting a significant fraction of non-Compton scattered photons. The spectra processing component can be easily implemented with different types of gamma-ray imagers, for example Anger-type cameras, and may also be retroactively fitted to existing gamma-ray camera systems.

A method for measuring radiation in a borehole, the method including placing a detector comprising a scintillator and a plurality of photodetectors in the borehole; detecting a radiation interaction with a first photodetector; detecting the radiation interaction with at least a second photodetector; and determining a location of the interaction from the detecting; wherein the location provides information regarding formations surrounding the borehole.

A method for a pulsed gamma-gamma density tool to simultaneously compensate for interactions due to the photoelectric effect and density variations caused by standoff enables a more precise determination of bulk formation density. This method includes the steps of providing a source of energetic particles and directing those energetic particles at a formation having a known photoelectric factor and electron density and capturing one or more photons either emitted or deflected from the formation either a first detector or a second detector. The first detector is spaced a first distance from the source, the second detector is spaced a second distance from the detector and a third distance separates the first detector from the second detector. Measuring a first total energy of the photons striking the first detector during a time interval and measuring a second total energy of the photons striking the second detector as a function of the time interval and disposing a first filter between the first detector and the formation effective to cause Pe response to match standoff influence thereby compensating for both effects simultaneously. In addition to the first filter, the required compensation may include a second filter between the second detector and the formation as well as adjustments to the respective first distance, second distance and third distance.

A method for measuring radiation in a borehole, the method including placing a detector comprising a scintillator and a plurality of photodetectors in the borehole; detecting a radiation interaction with a first photodetector; detecting the radiation interaction with at least a second photodetector; and determining a location of the interaction from the detecting; wherein the location provides information regarding formations surrounding the borehole.

A natural gamma tag marking materials for sub or permanent markers used in gamma logging operations, such natural gamma materials having a gamma count of between 200 and 1000 counts per second. The instant invention further discloses a typical Sub, for insertion in a drilling operation, utilizing natural gamma element compounds which are considered to be non-hazardous and effective as tag markers when used in wire-line logging operations.

A gamma adjustment method for a display device having a gamma conversion table of an input signal, the method comprising: selecting a plurality of sampled gray levels among the gray levels of the input signal; Sampling the brightness level of the output video signal related to the gray level; determining a first gamma conversion value corresponding to the sampling gray level based on the measured brightness level and storing the determined gamma conversion value; Calculating a second gamma conversion value corresponding to the gray level of the input signal excluding the sampled gray level based on the gamma conversion value corresponding to the gray level; and based on the stored first gamma conversion value and the calculated The second gamma transform value to set the gamma transform table.

The invention belongs to the field of nuclear physics research and application, and specifically relates to a gamma-gamma density logging distorted curve correction method. The invention provides a correction method for eliminating gamma-gamma density logging curve distortion produced due to rock radiation in the stage of gamma-gamma density logging data sorting. The method comprises the following steps: S1, selecting a correction depth section; S2, calculating the density value of a rock skeleton; S3, calculating the average correction coefficient value; and S4, calculating the rock density of the correction depth section and drawing a corrected gamma-gamma density curve. The problem that a curve fluctuates drastically in a uranium enrichment section before correction is solved. Accurate acoustic impedance data can be provided for seismic exploration, and the quality of gamma-gamma density logging can be monitored effectively. The correction method is also applicable to a gamma-gamma density logging distorted curve affected by a hole enlarge section and a hole collapse section.

A display apparatus includes a gamma data generator comprising a spatial pattern having at least a high gamma and a low gamma corresponding to a plurality of sub-pixels arranged in a matrix array in a space division configuration, a temporal pattern having the high gamma and the low gamma corresponding to the plurality of sub-pixels in a time division configuration and a spatio-temporal pattern having the high gamma and the low gamma corresponding to the plurality of sub-pixels in both a space and time division configuration, and configured to generate gamma data of a sub-pixel using the spatial pattern, the temporal pattern and the spatio-temporal pattern in a cascade configuration.

A calibration site for a gamma-gamma well logging tool for use in mineral exploration, the calibration site having a column consisting of a plurality of blocks of known densities; and a borehole through the column configured to accept the gamma-gamma well logging tool. Further, a method for calibrating a gamma-gamma well logging tool at the calibration site, the method including lowering the gamma-gamma well logging tool into a column consisting of a plurality of blocks of different known densities and having a borehole therein to receive the gamma-gamma well logging tool; raising the gamma-gamma well logging tool at a set rate; capturing a radiation count at a sensor of the gamma-gamma well logging tool; converting the radiation count to a recorded density for a particular depth at a computing device; and comparing the recorded density at each position of the column with the known densities.

The invention relates to a methotrexate dosage regimen determining method, a device, a storage medium and equipment. Through establishing a methotrexate inner metabolism dynamics model, in consideration of influence of different methotrexate metabolism related enzymes (folypolyglutamate synthetase and gamma-gamma-glutamyl hydrolase) contents to the methotrexate metabolism speed parameter, and thenthe metabolism condition of the methotrexate is simulated through the model, thereby determining the corresponding dosage regimen according to the methotrexate metabolism simulation condition, namelydetermining the dosage regimen according to the methotrexate metabolism related enzyme content differences between different patient individuals, thereby realizing more scientific and reasonable methotrexate dosage regimen, and realizing accurate medicament dispensing for aiming at different patient individuals.

A method for performing a measurement of a property downhole includes: using an instrument including an irradiator including a pulsed neutron generator, a moderator and a material including a high cross section for capturing thermal neutrons downhole, generating inelastic gamma photons from neutron interactions in the moderator and generating capture gamma photons from neutron interactions in the material; irradiating sub-surface materials proximate to the instrument with the inelastic gamma photons and the capture gamma photons; detecting radiation scattered by the sub-surface materials; and estimating the property according to the detected radiation. A system is also disclosed.

The invention relates to a Gamma-Gamma distribution parameter estimation method based on a double logarithmic cumulant expectation, and belongs to the technical field of atmospheric turbulence channel parameter estimation of free space optical communication systems. According to the method, a Gamma-Gamma distribution parameter estimation process is simplified greatly through Mellin transform, and a uniform parameter estimation method is built specific to the problems of low fractional moment (FMOM) parameter estimation accuracy and even error estimation in the prior art. Then, further improvements are made, and a concept of double logarithmic cumulant expectation is put forward, so that a finial parameter estimation expression is deduced. Compared with an FMOM, the Gamma-Gamma distribution parameter estimation method has the advantages that relatively high computing efficiency is ensured, and the parameter estimation accuracy is increased.

The invention discloses a tomographic gamma scanning and measuring method which comprises the following steps of: 1, performing transmitting measurement on a sample, namely (1) positioning and axially layering the sample; (2) selecting translation position points in equal interval on each layer; (3) rotating the sample around the central axis of a platform at each horizontal translation position point, and selecting eight rotating angles between 0 and 180 degrees in equal angle, wherein once measurement is performed while rotating once, and eight-time measurement is performed at each horizontal position point; 2, performing emission measurement on the sample; and 3, correcting the absorption attenuation of emitted gamma rays which penetrate through the measured sample by utilizing a dielectric wire attenuation coefficient obtained through transmitting gamma scanning measurement, and obtaining the radioactive content. The invention provides the tomographic gamma scanning and measuring method which is short in measurement time, high in analytical precision and high in measurement accuracy.

A downhole gamma ray density measurement system is described. The gamma ray density measurement system includes a pressure housing and a gamma ray source within the pressure housing. One or more detectors within the pressure housing detect gamma radiation. One or more low-attenuation inserts may be located in the pressure housing near the gamma ray source and / or one or more of the detectors. One or more high-attenuation inserts may be located in the pressure housing near the gamma ray source and / or one or more of the detectors.

The invention belongs to the field of precise three-dimensional measurement, and particularly relates to a method for calibrating a gamma value in a phase measurement system. On the basis of an ideal gamma distortion model, a gamma non-linear response model considering projector defocuses is created, and on the basis, a novel gamma value calibration method easy to implement is provided. The method includes 1), projecting two groups of raster images onto a to-be-tested target respectively, wherein the phase shift L and gamma' of the raster images are valued as 1 or positive integers greater than 1 respectively, and shooting the two groups of raster images by an industrial camera; 2), as to each group of raster images, calculating amplitude of kth harmonic wave k and then acquiring 2 / 1 and 2' / 1' after respective calculation; 3) calculating gamma and sigma of each pixel in each camera image respectively; 4), averaging the gamma of pixels in camera images to take the average value as a gamma value calibrated by the phase measurement system. By the gamma value calibration method, phase errors caused by system gamma nonlinearity can be effectively eliminated.

The invention provides a liquid crystal display device and a display device. The display device includes a display unit, a common voltage generation circuit, a gamma correction circuit, a drive circuit and a power conversion circuit. The common voltage generating circuit provides the common voltage to the display unit. The gamma correction circuit outputs a gamma voltage. The driving circuit provides grayscale voltages to the display unit according to the gamma voltage. The power conversion circuit includes a first conversion circuit and a second conversion circuit. The first and second conversion circuits are both input ends for connecting with a power supply, and the rest are two parallel branches separated from each other and not connected to each other. The first conversion circuit generates a first power supply voltage, the second conversion circuit generates a second power supply voltage, and the first and second power supply voltages are respectively output to the gamma correction circuit and the common voltage generation circuit. The gamma correction circuit uses the first power supply voltage as a reference voltage to generate a gamma voltage. The common voltage generation circuit generates a common voltage with the second power supply voltage as a reference voltage.

The present invention discloses a gamma density rapid-calculation method based on a perturbation theory, and specifically relates to the field of petroleum and natural gas development. According to the method, from a gamma-gamma density response principle, the perturbation theory is introduced to a density response, different standard densities of strata are selected as a reference, and an instrument-stratum model is established in combination with MCNP for simulation to obtain first-order and second-order Compton and photolectric sensitivity function databases, thus forming a gamma-gamma density rapid-calculation method at last. The method specifically includes the following steps: step 1: introducing the perturbation theory into the density response, and performing expansion, deformationand simplification on a formula to obtain a spatial dynamic response function expression form; step 2: according to a parameter of a selected gamma-gamma density instrument, establishing a three-dimensional MCNP numerical calculation model, and simulating to obtain a spatial dynamic response function database; and step 3: performing multielement nonlinear regression on multiple hybrid density responses, and seeking for a coefficient of a rapid calculation formula to obtain the rapid calculation formula for density.