228 results about "Linear gradient" patented technology

Spatial encoding in magnetic resonance imaging (MRI) techniques is achieved by sampling the signal as a function of time in the presence of magnetic field gradients, e.g., X, Y, and Z gradients. The gradient magnets have in the past been assumed to generate a linear gradient, and typical image reconstruction techniques have relied upon this assumption. However, to achieve high speed performance, gradient magnets often sacrifice linearity for speed. This non-linearity, in turn, results in distorted images, the distortion often being sufficiently large to compromise the usefulness of MRI images for stereotaxy or longitudinal studies, where precise volumetric information is required. The disclosure provides practical methods for correcting distorted images resulting from such non-linearity in the gradient fields, as well as distortions resulting from translational, rotational, and/or winding/design errors in the field generating devices. The methods employ spherical harmonic expansions of the gradient fields and fast Fourier transform techniques to provide well-corrected images without undue computational burdens.

The invention relates to a spectral imaging method and a spectrum imaging instrument of a snapshot-type high throughput, which aim at realizing a picture-type photograph. The spectrum instrument comprises a linear gradient filter array and an optical-field imaging mechanism, and the optical-field imaging mechanism comprises a primary mirror, a micro lens array and a detector. The filter array is arranged on an aperture diaphragm between lenses of the primary mirror, the filter array consists of a plurality of filters which have identical width and are arranged at intervals, and the filter is a linear gradient filter band with continuous spectrum. The micro lens array is arranged on an imaging surface of a front-mounted optical imaging system, and the detector is arranged on a focus plane of the micro lens array. The spectrum imaging method is characterized in that light in different directions transmitted or reflected by a target is imaged on one micro lens after being modulated by the primary mirror and the filter array, the light is dispersed by the micro lens onto a picture element of the detector to form a subimage, and finally three-dimensional spectrum image data is obtained. The complete spectrum image information of the target can be obtained through the photograph in one step, and the spectral imaging method and the spectrum imaging instrument can be used for monitoring and tracking a rapid variable or movable target.

There is provided a solid-state image sensing device including a pixel section in which cells are arrayed, each cell including a photoelectric conversion unit, a reading circuit reading out, to a detection unit, signal charges obtained by the photoelectric conversion unit, an amplifying circuit amplifying and outputting a voltage corresponding to the signal charges, and a reset circuit resetting the signal charges, an exposure time control circuit controlling an exposure time and controlling the exposure time to be equal for all cells, an A/D conversion circuit A/D-converting a signal output from the pixel section by changing a resolution of a signal level, line memories storing an A/D-converted signal, and a signal processing circuit processing output signals from the line memories to have a linear gradient with respect to an optical input signal amount by controlling an amplification factor in accordance with a resolution of a pixel output signal after A/D-conversion.

The invention discloses a vector graph filling method for a mobile terminal and comprises the following steps of: acquiring the information Grid (Xi) on the intersection point of edges of the polygon of the vector graph and pixels, and storing coordinates Yi on the Y axis into a linked list Grid Row (Yi) in turn; performing filling process, processing the Grid Rows related to the polygon in turn according to an ascending order of Y coordinates, wherein the step contains two parts, one is performing an anti-aliasing calculation on the intersection pixels of opposite edges and a scanning line and filling a proper value, the other is filling the internal area of the polygon on the scanning line, wherein the fill process can be a solid fill process, a linear gradient fill process or a radial gradient fill process. Compared with an active side filling method and a scanning line seed filling method, the vector graph filling method of the invention is more suitable for the display of a mobile terminal screen; besides, the vector graph filling method takes less time, has a high efficiency and supports a complex self crossing polygon filling process.

The invention belongs to the technical field of radar stealth, and particularly relates to a wideband spirally-coding radar cross-section (RCS) reducing metasurface insensitive to polarization and a design method thereof. The metasurface is of a two-dimensional limited size structure and is formed by arranging eight types of linear super-elements having different gradient directions in 8 by 8 according to a spiral sequence, the gradient directions of eight types of linear super-elements are respectively 0 degree, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees and 315 degrees, each linear super-element is of a two-dimensional limited size structure and is formed by six types of artificial electromagnetic structure units having different sizes in 6 by 6 according to linear gradient, the six types of artificial electromagnetic structure units realize 360-degree coverage, the phase gradient is 60 degrees, the spiral sequence is a single spiral circulation arrangement mode from outside to inside, each artificial electromagnetic structure unit is of a rotary symmetric reflection structure and comprises an upper-layer internal closed ring, an external Jerusalem metal structure, an intermediate-layer dielectric plate and a bottom-layer metal copper plate. The RCS reducing metasurface has the excellent characteristics of thin thickness, good robustness, ultra-wideband working and the like and is easy to process.

A device includes an optical splitter comprising a plurality of splitter outputs. The splitter outputs are out of phase and include a non-uniform phase front. The device includes a one-dimensional phase compensation array communicating with the optical splitter. The phase compensation array receives the non-uniform phase front and outputs a uniform phase front. The phase compensation array includes a plurality of array outputs. The device includes a tunable linear gradient phase shifter communicating with said phase compensation array to impart a linearly-varying phase shift across said plurality of array outputs, thereby steering a beam along a first angle in a first plane. The device includes a waveguide grating out-coupler communicating with said linear gradient phase shifter, and a uniform phase shifter communicating with the waveguide grating out-coupler. The uniform phase shifter steers the flat phase front along a second angle in a second plane perpendicular to said first plane.

The invention relates to a method for separating and preparing key acid flavor components in cigarette mainstream smoke. The method takes the acidic components in the cigarette mainstream smoke as a raw material, the acidic components in the cigarette mainstream smoke are subjected to linear gradient elution through medium-pressure prepared liquid chromatography, and the same volumes of eluted fractions are sequentially collected; and the gas chromatography-mass spectrometry is adopted to analyze all the eluted fractions, and with the help of sense smoke panel test, three key acid flavor components F4, F5 and F6 are screened finally. The result shows that the fraction F4 has obvious functions of improving smoke impact, increasing smoke concentration and reducing stimulation; the fraction F5 has obvious functions of improving aroma quality and smoke impact and increasing smoke concentration as well as the functions of increasing aroma quantity, covering miscellaneous gases and improving permeability; and the fraction F6 has the obvious functions of improving aroma quality, increasing aroma quantity, improving permeability and smoke impact and increasing smoke concentration as well as the function of improving residual taste.

The invention discloses a high-efficient multi-projector splicing and blending method. One quarter of an arc is taken as a blending curve for an edge blending color correction method based on the existing geometric correction, and a graded combination linear gradient brightness compensation method is adopted for the light leakage phenomenon. The method does not need to spend great workload and can realize good splicing effect and reflect the high efficiency, so the method can be widely applied in various multi-projector splicing display systems.

The invention discloses a portable compact complete-polarization high-spectral imaging unit comprising a front lens system, an imaging lens, a linear polarizer array, a linear gradient filter array and a detector arranged in order on a same light path. Incoming light enters a primary image surface of the front lens system; parallel beams passing through enter the imaging lens; the light then passes the linear polarizer array and the linear gradient filter array to image the detector. The portable compact complete-polarization high-spectral imaging unit has the advantages of simplicity in processing and adjustment, high stability, high energy utilization rate, good imaging quality, high resolution, compact structure, small size and low production cost.

The invention discloses a method for purifying dermatan sulfate from a heparin byproduct. The method comprises the following steps of: using the heparin byproduct as a raw material; dissolving the heparin byproduct, and then adding potassium acetate into the dissolved heparin byproduct; adjusting the pH value of solution by using acetic acid to generate a deposit, wherein clear solution is sulfate polysaccharide solution; adding a Ban's agent and saturated sodium hydroxide solution into the sulfate polysaccharide solution; centrifugally collecting the deposit; performing re-precipitation; dissolving the deposit again; washing away copper ions by using a chromatography column with anion exchange properties and sodium chloride solution; performing linear gradient elution by using the sodium chloride solution; collecting eluant; and evaporating and concentrating the eluant, and depositing the eluant by using ethanol to obtain high-purity dermatan sulfate. The method has the advantages of simple purification process, high purification yield, low cost, easy amplification and suitability for industrial production.

The invention discloses a method for separating hyaluronate tetrasaccharide from hyaluronate hexasaccharide, and belongs to the technical field of bioengineering. The method comprises the following steps: adopting Q Sepharose fast flow as an ion exchanger, Tris-HCl with the pH value of 8-9 as an equilibrium liquid, and 0.125 M NaCl with the pH value of 8, performing linear gradient elution to separate hyaluronate tetrasaccharide from hyaluronate hexasaccharide, and desalting to obtain pure products of hyaluronate tetrasaccharide and hyaluronate hexasaccharide.

The invention relates to a rapid separation liquid chromatography detection method for naoxintong capsules. The method comprises the chromatographic conditions that octadecyl bonded silica gel columns serve as filling agents, 0.1% formic acid water serves as an A mobile phase, acetonitrile serves as a B mobile phase, the volume ratio of the A mobile phase to the B mobile phase is 10-85:15-90, and linear gradient elution is performed, the flow velocity is set at 0.20 mL.min<-1>, the column temperature is set at 25 DEG C, and the sample introduction volume is 5 microliters. The content of gallic acid, tanshinol, hydroxysafflor yellow A, chlorogenic acid, amygdalin, protocatechualdehyde, epicatechin, caffeic acid, albiflorin std, ononin, paeoniflorin, rutin, salvianolic acid A, cinnamic acid, fermlononetin, dihydrotanshinone I in the naoxintong capsules is detected. The detection method has the advantages of being rapid, stable and accurate.

The invention discloses a textile optical property testing system based on linear gradation filter, which is composed of a light source, a collimator tube, a spectroscope, a linear gradation filter, an opto-electrical diode array detector, a signal processing circuit and a computer. The system utilizes the advantages of linear gradation filter having simple and compact structure, wide continuous spectrum and good thermal stability, which can finish the light splitting of each spectrum section. The test result can effectively reflect the reflection, transmission, adsorption and other performances. The invention is mainly suitable for testing the reflection, transmission, adsorption and other performance of dress textile, decoration textile and industry textile to various lights.

First order gradient errors are canceled with no current source splitting by placing consecutive current sources symmetrically around the center of the array. Consecutive elements that correspond to small input amplitudes (mid-scale codes) make a smaller spatial jump than those correspond to larger signal amplitudes. Both linear and second order gradients are reduced by splitting each current cell into two and placing sub-elements symmetrically with respect to the center of the array to address the linear gradient effect. To address second order gradients, current element placement follows a pattern such that consecutive element pairs are chosen with one of the pair being placed with respect to the zero error contour of the second order gradient so as to have a positive error and the second of the pair being placed so as to have a negative error resulting in reduced second order error accumulation.

The invention provides an absorption region structure for a unitraveling carrier photodiode. The absorption region structure employs an In1-xGaxAsyP1-y material for growth, wherein the x and y express material components of a Ga element and a As element, the x is larger than 0 and is less than 1 and the y is larger than 0 and is less than or equal to 1; and the component parameters x and y change in a linear gradient mode or in a step type gradient mode, so that the gradient change of the forbidden band width in the absorption region is realized. Moreover, with selection of the component parameters x and y, the lattice constant of the In1-xGaxAsyP1-y material matches InP and the forbidden band width is not larger than that of photon energy of laser with the wavelength of 1.5 microns. According to the invention, with utilization of a built-in electric field introduced by a gradient energy band structure, the electric field intensity in the absorption region can be enhanced obviously; and the drift of electrons can be accelerated effectively based on the enhanced electric field and the transition time at the absorption region can be shortened. Therefore, the electron transition time in the absorption region of the unitraveling carrier photodiode can be reduced effectively. And utilization of the absorption region structure has the great significance in improving the bandwidth of the device and realizing the ultra-high-speed wireless communication system based on the device.

The invention relates to a linear gradient optical filter of 0.4 to 1.1 micrometers and a preparation method thereof, which belongs to the field of optical systems. The linear gradient optical filter takes K9 glass as a film coating substrate and takes titanium dioxide and silicon dioxide as a film coating material; and the design coating of the linear gradient optical filter is K9/(LHLH2LHLH)3/Air, wherein H and L are respectively the titanium dioxide and the silicon dioxide with 1/4 wavelength optical thickness of a high and lower refractive index material; a linear gradient optical filter line is provided with 10 channels on a wave band of 0.4 to 1.1 micrometers, the relative bandwidth is 6.8 percent, and any position at the middle of a substrate only transmits one kind of light with a specific wavelength within 0.4 to 1.1 micrometers. The linear gradient optical filter is combined with an array detector, optical systems and mechanic systems of instruments can be simplified, and the reliability and stability of the instruments are improved so that the instruments are miniaturized and convenient to carry; and more importantly, the linear gradient optical filter can identify different optical radiations simultaneously and quickly detect different spectral radiance at the same time.

The invention discloses a regular octagonal gradient magnetic field coil, which comprises two regular octagonal coils, wherein the axes of the two regular octagonal coils are coined, and the current directions of the two regular octagonal coils are opposite. A magnetic field with complete linear gradient is formed on the axes, so the coil can solve the problems that the processing difficultly of the coil is high when double-probe optical pumping type and proton type gradient magnetometers are used for calibrating the magnetic induction strength, and the coil is loosened after being used for a long time.

The invention provides a modeling method for a cucumber GA-RBF photosynthetic rate prediction model integrated with stomatal conductance. The method comprises the steps: utilizing a multi-factor nested test to obtain the experimental data taking the stomatal conductance, the temperature, the CO2 concentration, the illumination intensity and the relative humidity as input and taking the apparent photosynthesis rate as output; utilizing a genetic algorithm to perform initialization of population; according to the given initial range of the spread parameters, calculating a fitness function; and through selection, intersection and variation, finding out the optimal spread parameter in an RBF neural network, and constructing a cucumber GA-RBF photosynthetic rate prediction model integrated with stomatal conductance. The test result shows that the predicted value and actual measurement value determination coefficient is 0.99878; the linear gradient is 0.99781; the error is less than 6%; compared with the photosynthetic rate prediction model which does not use the genetic algorithm to optimize the RBF algorithm and does not integrated with stomatal conductance and the cucumber GA-RBF photosynthetic rate prediction model which is not integrated with stomatal conductance, the training result has better prediction effect.

The invention discloses a linear expansion coefficient measuring instrument based on the Hall effect, which includes a heating module and a deformation measurement module. Components, control circuits, display screens. It is characterized in that: one end of the metal rod to be tested is fixed, and the other end is in contact with the lever; one end of the lever is fixed, and the other end is provided with a Hall element; the position of the Hall element is in a linear gradient magnetic field ; The gradient magnetic field is placed opposite to each other by two identical magnets. The measuring instrument uses two physical methods of lever and Hall effect to amplify the small deformation of the material to be measured in two stages, and realizes the accurate measurement of the linear expansion coefficient. The invention has simple measurement process, intuitive and obvious reading, easy installation and operation, low cost and accurate measurement result.

The invention discloses a GIS insulator surface charge accumulation inhibition method based on linear gradient treatment; the method comprises the following steps: 1, preparing an epoxy resin material; 2, using a gradient temperature solidification method to process the epoxy resin material; 3, carrying out gradient design for the epoxy resin insulation sample: a, splitting the surface of the epoxy resin insulation sample into 5 rectangles tightly connected from left to right, and decreasing the relative dielectric constants of the rectangles in order; b, placing the epoxy resin insulation sample into a magnetron sputtering device, sputtering different positions for different time ranges varying from 0-60min, thus obtaining the epoxy resin material with two dimension gradient distribution. The method can inhibit the insulator surface charge accumulation under an AC voltage, thus improving the insulator voltage withstand performance, and improving the GIS operation stability and powersystem safety.