30results about How to "Imaging results are accurate" patented technology

The invention relates to a longitudinal and transverse wave separation method without separation artifacts, and belongs to the technical field of seismic wave information processing. The invention mainly overcomes the defects in the prior art, and provides a longitudinal and transverse wave separation method without separation artifacts, which comprises the following specific steps: carrying out forward modeling by using a first-order speed-strain equation, and carrying out longitudinal and transverse wave decoupling based on the formula and a longitudinal and transverse wave decoupling equation to obtain a separated longitudinal and transverse wave speed field. According to the invention, the phase and the amplitude of the separation result are not changed, and the separation result has no separation artifact; accurate longitudinal and transverse wave separation provides support for forward modeling and understanding of seismic wave propagation, elastic waves are relatively complex due to the fact that the elastic waves include longitudinal and transverse waves, and coupling of the longitudinal and transverse waves causes inconvenience to understanding of propagation rules of a wave field during forward modeling of the wave field of the elastic waves. Accurate longitudinal and transverse wave separation provides support for elastic wave imaging, surface data longitudinal and transverse wave separation, microseism positioning and the like depending on elastic wave field continuation algorithms.

The invention discloses a finite difference simulation method for seismic wave propagation in a pre-compressed fixed medium, which comprises the following steps: 1) using the elastic wave propagation equation described in the pre-compressed stress environment in the acoustoelastic technology to describe the wave propagation under the pre-compressed solid condition 2) Using the known elastic modulus of the rock, a uniform layered medium model is established; 3) Differential elastic wave propagation equations are used by the rotating staggered grid finite difference method; 4) The boundary of the uniform layered medium model in step 2) Apply unsplit convolution to perfectly match the layer absorption boundary; 5) Under different stress field conditions, use the rotating staggered grid finite difference method to perform acoustoelastic simulation on the uniform layered medium model, and verify the simulation accuracy; 6) Establish a double-layer medium model, Repeat steps 3)-5) to perform finite-difference simulation of seismic wave propagation in precompressed solid media to obtain seismic wave fields under different stress fields.

The invention provides a waterborne fracturing stress measurement and induction fracture dynamic imaging integration device, and belongs to the field of ground stress testing. The waterborne fracturing stress measurement and induction fracture dynamic imaging integration device comprises a fracturing packer, an ultrasonic wave imaging system and a push-pull valve, the ultrasonic wave imaging system is arranged on a flow dividing center rod of the fracturing packer, the ultrasonic wave imaging system and the fracturing packer can descend a well together, and real-time hole wall imaging is achieved, ground stress of a hole wall rock can be rapidly measured, hydraulic fracturing measurement and induction fracture imaging can be achieved only by descending the well once, ground stress measuring efficiency is greatly improved, the ultrasonic wave imaging system dynamically images in real time, and imaging results are more accurate and reliable.

The invention belongs to the field of ultrasonic detection and imaging, and provides a fast imaging algorithm based on ultrasonic ring array synthetic aperture receiving. The ring array ultrasonic transducer is used to transmit and receive ultrasonic signals in a synthetic aperture receiving mode, and the ring array ultrasonic transducer The array elements are grouped by each group of n adjacent array elements, and the index matrix D of the sector area formed by the first group of array elements 1 to n and the center of the ring array ultrasonic transducer is calculated. 1 ; set the initial value i = 1; use the synthetic aperture algorithm to obtain the corresponding local imaging result I i ; Obtain the i-th index matrix D through the rotation transformation i , and repeat the first two steps until all local imaging results are obtained; all local imaging results are superimposed and fused according to their positions to obtain the final imaging result. Through the algorithm provided by the present invention, the arc-shaped artifacts in the traditional synthetic aperture imaging algorithm can be effectively removed, and the performance of the algorithm can be greatly improved.

The invention belongs to the technical field of positron emission computed tomography (PET) imaging, and particularly relates to a method for rapidly marking Cys-Annexin V through <18>F and application of obtained <18>F-Al-NOTA-Cys-Annexin V in the aspect of detecting cell apoptosis. According to the method for rapidly marking Cys-Annexin V through <18>F, <18>F-Al-NOTA-Maleimide is adopted to mark Cys-Annexin V for the first time, the marking time used by the marking method is short, the marking rate is high, the fact of using <18>F for positioning and marking Cys-Annexin V is achieved, and <18>F-Al-NOTA-Cys-Annexin V maintains good affinity with PS, has a good imaging effect by serving as a PET imaging agent and has the more ideal imaging specificity.

The invention provides a retrosynthetic aperture radar azimuth calibration method which comprises the steps of carrying out range compression and translation compensation on imaging data, carrying out Keystone transformation correction linear range walking on a self-focused signal, determining medians of effective rotational speeds, a search interval and search point number, carrying out secondary phase term compensation on a signal after keystone transformation with each effective rotational speed to be estimated, carrying out azimuth imaging and obtaining an image entropy, after traversing all the effective rotational speeds to be estimated, searching the minimum image entropy, and taking the effective rotational speed corresponding to the minimum image entropy as the estimated effective rotational speed. After obtaining the estimated effective rotational speed, the search is carried out in a smaller interval near the value, the whole process is iterated for 3-4 times, and very high estimated accuracy can be achieved.