10 results about "Dc resistivity" patented technology

The utility model discloses a dragging-type multichannel direct current resistivity acquisition system. The dragging-type multichannel direct current resistivity acquisition system comprises a mobile platform and a plurality of dragging-type electrodes connected with the mobile platform, the dragging type electrodes comprise two power supply electrodes and at least one group of exploration electrodes, the exploration electrodes and the power supply electrodes are arranged in a dipole-dipole device, all the dragging type electrodes are in dragging connection with the mobile platform according to a fixed arrangement interval, and all the dragging type electrodes are driven by the mobile platform to integrally move and drag on the exploration ground; all the dragging type electrodes are electrically connected with a multi-channel direct-current resistivity acquisition host arranged on the mobile platform through a multi-channel large cable; and the active water supply device is used for improving the electric conductivity between the dragging type electrode and the exploration ground. According to the utility model, the design of the active water supply device and the dragging type electrode is adopted, so that non-driven type electrode power supply and potential measurement on flat grounds such as land dams and roads are realized, and the problem of low data acquisition efficiency of a traditional high-density resistivity method is effectively improved.

The invention discloses a method for data inversion by utilizing a multipoint geological statistical structure constraint direct current electric method, which belongs to the field of geophysical exploration, and comprises the following steps: based on geological drilling data, establishing a model containing geological structure information by adopting a multipoint geological statistical algorithm, and constructing an underground stratum structure operator by utilizing the model; a structure operator is added to a regularization term, an initial resistivity model is given to calculate a data residual term, and an inversion objective function with structure constraint is formed; in the inversion process, a finite memory quasi-Newton optimization algorithm is adopted to carry out iterative optimization on a target function until the difference between forward modeling simulation data and actually measured data reaches a set threshold value, and constraint inversion is completed; and finally, outputting the resistivity inversion model. According to the method, the problems of fuzzy stratum boundary, reduced resolution and the like caused by regularization smooth constraint in a traditional method are reduced, and the method is suitable for subsurface stratum structure detection and fine imaging in a complex geological environment and has wide application value.

The present application relates to the engineering geophysical exploration technical field, specifically to a kind of complex terrain direct current resistivity three-dimensional forward and inversion method and system based on octree;Method includes: establishing target information sequence;Three-dimensional geoelectric model based on octree grid is constructed using target information sequence, and local encryption is carried out in the surface near the detection area and electrode neighborhood, and the modeling result is output;Based on the modeling result, the underground active unit located below the terrain surface and the air unit located above the terrain surface are distinguished, the finite volume method is used to discretize and solve the direct current resistivity method potential field control equation of underground active unit, the theoretical potential response corresponding to electrode device is obtained, and the theoretical apparent resistivity response is obtained;Construct inversion objective function, and iteratively update resistivity parameters of three-dimensional geoelectric model using inversion strategy;The three-dimensional resistivity imaging result of underground medium in detection area is output through updated three-dimensional geoelectric model, and adverse geological body is identified.

The application discloses a kind of towed land multi-channel direct current resistivity exploration systems, including mobile platform and several towed electrodes connected with mobile platform;The towed electrode includes two power supply electrodes and at least one set of exploration electrode arranged as dipole-dipole device with power supply electrode, all towed electrodes are connected with mobile platform according to fixed arrangement spacing, and all towed electrodes are moved as a whole on the exploration ground by mobile platform;All towed electrodes are electrically connected with the multi-channel direct current resistivity acquisition host set on mobile platform through multi-channel large cable;It also includes active water supply device for improving the conductivity between towed electrode and exploration ground.The application uses active water supply device and towed electrode design, realizes the non-punching electrode power supply and potential measurement for land embankment, highway and other flat ground, effectively improves the problem of low data acquisition efficiency of traditional high-density resistivity method.

The invention discloses a method for discriminating a water-rich area in front of a roadway based on direct-current resistivity relevancy, and the method comprises the steps: obtaining potential data through employing an electrical measuring line which is provided with a plurality of electrodes at equal intervals at a time, obtaining an apparent resistivity value after calculation, determining a corresponding depth value, and obtaining a resistivity sounding curve graph; then, according to the change shape of the curve, the front and back of the water-rich area relative to the tunneling head-on can be preliminarily judged, and if the water-rich area is back, subsequent roadway tunneling is directly carried out without subsequent steps, so that the roadway tunneling efficiency is effectively improved; and if the tunneling head is in the front, gridding the detection range around the tunneling head to form a plurality of target units, calculating the relevancy between the actually measured resistivity value and the forward modeling resistivity value of each target unit, and finally circling a high relevancy value range, namely accurately obtaining the range of the water-rich area and the position of the water-rich area. According to the method, the arrangement of the detection equipment and the subsequent judgment process are simple and rapid, the detection cost is relatively low, the efficiency and safety of roadway tunneling are effectively improved, and the method has wide practicability.

This invention discloses a joint advanced detection method based on borehole transient electromagnetics and DC resistivity. Advanced boreholes are deployed along the tunneling direction at the tunnel face to collect and invert transient electromagnetic data, obtaining the borehole transient electromagnetic inversion results. Based on the inversion results and corresponding estimation methods, Gaussian variation models in three principal axis directions are calculated and extended to arbitrary directions. Subsequently, the Gaussian variation models in arbitrary directions are substituted into the covariance calculation formula to calculate the covariance value between any two grid cells in the desired detection area, and assembled into a covariance constraint matrix. Finally, this matrix is ​​introduced as a regularization term into the inversion objective function of DC resistivity advanced detection, achieving covariance-constrained DC resistivity inversion, thereby significantly improving the inversion stability and inversion imaging accuracy of DC resistivity advanced detection. This method is suitable for advanced detection scenarios such as tunnel faces or underground coal mine tunneling.

The invention discloses a combined advanced detection method based on borehole transient electromagnetism and direct-current resistivity, and the method comprises the steps: laying an advanced borehole in a tunnel face in a tunneling direction, carrying out the collection of borehole transient electromagnetic data, and carrying out the inversion, and obtaining a borehole transient electromagnetic inversion result; according to an inversion result and a corresponding estimation method, calculating to obtain Gaussian variation models in three main axis directions, and expanding the Gaussian variation models to any direction; then, the Gaussian variation model in any direction is substituted into a covariance calculation formula, a covariance value between any two grid units in the area needing to be detected is obtained through calculation, and a covariance constraint matrix is assembled; and finally, introducing the matrix as a regularization item into an inversion objective function of direct-current resistivity advanced detection to realize covariance constrained direct-current resistivity inversion, so that the inversion stability and the inversion imaging precision of the direct-current resistivity advanced detection are remarkably improved, and the method is suitable for scenes such as tunnel face or coal mine underground tunneling advanced detection and the like.

The present invention belongs to the technical field of soft ferrite materials, and specifically relates to a praseodymium-doped nickel-zinc-cobalt ferrite and a preparation method thereof, wherein the molecular formula is: Ni m Zn n Co 1‑m‑n Pr x Fe 2‑x O4, wherein 0<x≤0.1, 0.5≤m<1, 0<n<0.5, is prepared by combining sol-gel self-propagating combustion method and microwave sintering; in addition, Pr 3+ Replace Fe 3+ To improve the magnetic and electrical properties of the material, its preparation process is simple and pollution-free. The resulting material also achieves a high cutoff frequency, a high DC resistivity, and a low dielectric loss. It can provide a reference for the development of high-frequency miniaturized electronic equipment and is expected to enhance my country's core competitiveness in the miniaturization and integration of high-frequency and even ultra-high-frequency electronic devices.

An inversion method of direct-current (DC) resistivity based on unsupervised deep learning (DL), includes: constructing an unsupervised DC resistivity inversion network architecture, and adding a dynamic smoothing regularization term to a loss function; constructing a simulated sample database with reference to geologic conditions of an explored region, and constructing an actual sample database by using data generated in an early stage of engineering by means of a domain transfer method; and pre-training an unsupervised neural network by using the simulated sample database, then performing secondary training on the network by using the actual sample database by means of a linear probing and full fine tuning-based transfer learning method, finally, substituting newly collected observation data into the trained network, performing, based on a network constraint, iterative inversion on a single actual sample multiple times, and obtaining a predicted resistivity model.

The invention provides a mine water disaster dynamic monitoring method based on an electromagnetic perspective method. The mine water disaster dynamic monitoring method comprises the following steps: acquiring a time sequence signal of resistivity data acquired by a direct current resistivity method for a mine measuring area; carrying out feature extraction on the resistivity data time sequence signal of the mine measuring area obtained in the monitoring period to obtain feature information; comparing the water inrush threshold value with the characteristic information, and surveying and marking a possible water inrush range; and performing inversion according to the electrical data of the target area to form a graph. According to the technical scheme, the water inrush accidents possibly existing on the coal seam working face can be rapidly, accurately and dynamically monitored, then dynamic disaster early warning in coal mine production work is achieved, and safe production is guaranteed. The mine water disaster monitoring system is used for dynamically monitoring the specific conditions of mine water disasters.