311 results about "Variable density" patented technology

The present invention is directed to a gas line electron beam exciter, gas line electron beam excitation system and method for exciting a gas using an electron beam exciter. The electron beam exciter generally comprises a variable density electron source for generating a cloud of electrons in an electron chamber and a variable energy electron extractor for accelerating electrons from the electron chamber as an electron beam and into an effluent stream for fluorescing species in the effluent. The electron density of the electron beam is variably controlled by adjusting the excitation power applied to the variable density electron source. The electrons in the electron chamber reside at a reference electrical potential of the chamber, typically near ground electrical potential. The electron energy of the electron beam is variably controlled by adjusting an electrical potential across the variable energy electron extractor, which energizes the electrons through an extraction hole of the chamber and toward the extractor. The greater the difference in the electrical potential between the electron extractor and the electron source, the higher the energy imparted to the electrons in the electron beam. The excitation power applied to the electron source can be adjusted independently from the electron energy of the electron beam, thereby altering the electron density of the electron beam without changing the energy level of the electrons of the electron beam.

The invention discloses a rapid magnetic resonance imaging method based on a CS (compressed sensing) technique. The traditional imaging method has relatively low speed and high hardware cost. The method comprises the following steps of: firstly, acquiring variable-density random k spatial data; specifically, determining under sampling rate according to the structural sparsity of an image; carrying out sparse acquisition in a k-space central area and carrying out random sparse acquisition in a k-space peripheral area according to the under sampling rate by combining with the k-space energy distribution rule to generate a variable-density random data acquisition path; acquiring the data according to the determined data acquisition path; then carrying out sparse conversion on an MRI image; and finally, nonlinearly optimizing and reconstructing the image based on Li norm minimum. The method breaks through the limit of the classical Nyguist sampling theorem, accurately reconstructs the signal of the MRI image through randomly acquiring few data points by utilizing a nonlinear optimization algorithm and greatly shortens the data acquisition time.

The present invention provides variable density fluid compositions and methods for using such compositions in a subterranean formation. One exemplary embodiment of the variable density fluid compositions of the present invention comprises a variable density fluid comprising: a base fluid, and a portion of variable pressure weighting material particles.

The invention provides a diffusion-tensor imaging method, which comprises the following steps of: respectively performing K space under sampling on an imaged target in each diffusion gradient direction in the same variable density sampling form to acquire K space under sampling data of each diffusion gradient direction; selecting the K space under sampling data of any diffusion gradient direction in the K space under sampling data of each diffusion gradient direction as reference K space data, and converting the reference K space data to acquire a reference image; making a difference between the K space under sampling data of each diffusion gradient direction and the reference K space data to acquire differential chart K space under sampling data of each diffusion gradient direction; rebuilding the differential chart K space under sampling data of each diffusion gradient direction to acquire a differential chart of each diffusion gradient direction; and combining the differential chart of each diffusion gradient direction and the reference image to acquire a diffusion-tensor image in each diffusion gradient direction. The invention also provides a diffusion-tensor imaging system at the same time.

Spot illumination apparatus and methods are described. According to one implementation a spot luminaire includes a light source for emitting a beam of light and a projection lens configured to project the beam of light towards a distant target. A first field stop, through which the beam of light passes, is positioned between the light source and the projection lens. A filter apparatus is positioned proximate the first field stop and is adapted for selectively moving at least one variable density filter across the beam of light. A relay lens group is positioned between the first field stop and the projection lens. The relay lens group is configured to prevent the at least one variable density filter from being imaged by the projection lens. Methods for providing stage lighting are also described.

The invention relates to the technical field of horizontal well fracturing, and discloses a new fracturing process suitable for the encrypted development of a shale gas well, which comprises the following steps of (1) collecting the data; (2) analyzing the stress and compressibility; (3) designing the interval of the segment clusters; (4) designing the number of clusters; (5) carrying out the temporary plugging design in the midway; (6) designing the construction displacement; (7) designing a fracturing scale; and (8) designing a sand adding mode. According to the essence of the method, the small-section multi-cluster segmented design of reducing the section cluster spacing is carried out on the target horizontal well by analyzing the single well ground stress characteristics and the compressibility of the shale gas well of encrypted development; meanwhile, the pumping design of the variable-density perforation, midway ball throwing temporary plugging and continuous sand adding is combined, and finally, the effect of improving the single well transformation complexity and the reservoir transformation efficiency is achieved, the volume transformation of the whole horizontal well isachieved, the crack complexity is improved, the transformation strength is improved to a larger extent through improvement of a sand adding mode and a pumping program, and meanwhile the single well construction cost is reduced.

A fluid ejection system and method for variable density pattern forming by producing a plurality of large, mid-sized and small spots. The plurality of large, mid-sized and small spots are produced by a plurality of large, mid-sized and small nozzles, each having a predetermined nozzle diameter. Furthermore, the plurality of large, mid-sized and small spots are placed on different grids, where the grid spacing for at least one of the pluralities of smaller spots is less than the grid spacing of the plurality large spots and is offset from it. The sizes, selection and spacing of the spots are designed to provide a substantially uniformly increasing area coverage from no coverage all the way to full coverage.

The parameters of an optical code are optimized to achieve improved signal robustness, reliability, capacity and/or visual quality. An optimization program can determine spatial density, dot distance, dot size and signal component priority to optimize robustness. An optical code generator employs these parameters to produce an optical code at the desired spatial density and robustness. The optical code is merged into a host image, such as imagery, text and graphics of a package or label, or it may be printed by itself, e.g., on an otherwise blank label or carton. A great number of other features and arrangements are also detailed.

Provided is a method for producing a high temperature micron-scale speckle, belonging to the technical field of optical measurement mechanics. The invention is technically characterized in preparing the high temperature micron-scale speckle having the advantages of simple operation, flexibility and easy implementation in the instrument environment of an electron beam lithography machine which is a mature commodity. The speckle with properties of variable density, variable depth and variable size can be produced by changing magnification, beam intensity and etching time of the electron beam optical exposure system, suitable for the study of the microscopic deformation behavior of different materials in a high-temperature environment.

Variable-density (VD), sequentially-interleaved sampling of k-space coupled with the acquisition of reference frames of data is carried out to improve spatiotemporal resolution, image quality, and signal-to-noise ratio (SNR) of dynamic images. In one example, ktSENSE is implemented with a non-static regularization image, such as that provided by RIGR or similar technique, to acquire and reconstruct dynamic images. The integration of ktSENSE and RIGR, for example, provides dynamic images with higher spatiotemporal resolution and lower image artifacts compared to dynamic images acquired and reconstructed using ktSENSE alone.

An image processing apparatus performs a density adjustment process for generating an image containing a copy-forgery-inhibited pattern image for warning against the use of copy products. To help users to easily adjust the density of a latent image portion and a background portion in the copy-forgery-inhibited pattern image, the image processing apparatus determines a density relationship of the latent image portion and the background portion by performing a plurality of adjustment operations, in combination, different in the amount of adjustment relating to the range of variable density in at least one of the latent image portion and the background portion, and sets, based on the density relationship, the density data of each of the latent image portion and the background portion in the data of the copy-forgery-inhibited pattern image.

A heat transfer structure includes a heat transfer module having a plurality of heat transfer members in the duct chamber with the density increased in the direction of the flow of the coolant and having a greatest density adjacent to the position of a heat source attached in thermal contact with the heat transfer module. The profile of the duct chamber is adjusted to the position of the heat source to increase the velocity of coolant directly under the heat source and to partially or completely block the coolant flow to the areas which do not need to be temperature adjusted. The heat transfer members may be formed as pin fins fabricated from springs compressed to a predetermined density in a direction perpendicular to the longitudinal axis of the spring (and/or in parallel to the longitudinal axis of the heat transfer module).

After a variable-density image of a target object is inputted and edge pixels representing the contour line of the target object are extracted from the image, the directions of these edge pixels are calculated, while straight-line portions in the contour are labeled according to their directions. Those of the edge pixels, which have the same direction as that of any of the straight-line portions, are assigned the same label. Line segments are then extracted as assemblies of those of the edge pixels which are continuous on the image and have a same assigned label. For labeling the directions of the straight-line portions, a histogram may be prepared, based on the numbers of edge pixels having different directions. Peaks are then extracted from the histogram and the labels are set to the directions corresponding to these peaks. Alternatively, labels may be set to each of expected directions of straight-line portions of the contour of the target object, the same labels being assigned to edge pixels having the same direction.

The ultrasound training mannequin (100) is a device that provides a realistic medical training device for use by medical personnel, especially those in the field of emergency medicine, to gain experience in applying and analyzing the results of common ultrasound examinations. The mannequin (100) comprises a life-size model of the male torso. The mannequin (100) has a simulated human skin (20) and tissue structure (22) made of a silicone. Internal organs, such as the lungs, heart, liver, kidneys, gall bladder, urinary bladder, and spleen are placed inside the model in their normal occurring relative positions. Heavier organs are modeled with a variable density silicone material to simulate the actual sonic density of these organs. The lungs are modeled with a variable density foam material to simulate the sonic density of actual lungs. The mannequin (100) also includes artificial venous and arterial channels emanating from and terminating at the heart.

Spiral imaging has recently gained acceptance for rapid MR data acquisition. One of the main disadvantages of spiral imaging, however, is blurring artifacts due to off-resonance effects. Dixon techniques have been developed as methods of water-fat signal decomposition in rectilinear sampling schemes, and they can produce unequivocal water-fat signal decomposition even in the presence of B₀ inhomogeneity. Three-point and two-point Dixon techniques can be extended to conventional spiral and variable-density spiral data acquisitions for unambiguous water-fat decomposition with off-resonance blurring correction. In the spiral three-point Dixon technique, water-fat signal decomposition and image deblurring are performed based on the frequency maps that are directly derived from the acquired images. In the spiral two-point Dixon technique, several predetermined frequencies are tested to create a frequency map. The techniques can achieve more effective and more uniform fat signal suppression when compared to the conventional spiral acquisition method with SPSP pulses.