64 results about "Dc resistivity" patented technology

The invention discloses a method for positioning an artificial wetland clogging area through a resistivity curve. The method includes the steps that first, a direct-current resistivity symmetrical four-pole sounding device is arranged above an artificial wetland, and the apparent resistivity is measured according to the mode that the electrode spacing becomes bigger and bigger; second, a power supply positive electrode A, a power supply negative electrode B, a measurement electrode M and a measurement electrode N of the direct-current resistivity symmetrical four-pole sounding device are all arranged symmetrical about a measurement point, and the apparent resistivity (please see the formula in the specification) of the electrode spacing is calculated every time the power supply electrode spacing is changed; third, the measured apparent resistivity is subjected to inversion, and the resistivity depth measurement curve is drawn according to the resistivity values obtained through inversion; fourth, the non-clogging area of the artificial wetland has the low resistivity characteristic, the clogging area of the artificial wetland has the high resistivity characteristic, and on the resistivity depth measurement curve, the vertical spatial position of the clogging area in the measurement point is determined according to the changing characteristic of the resistivity value. According to the method, on the basis of the conductivity difference of dielectric, the artificial wetland clogging area can be positioned through the resistivity difference.

The invention provides a broadband high impedance MnZn ferrite material, which comprises main components and assistant components. The main components comprise 47 to 50 mol percent of Fe203, 29 to 35 mol percent of Mn3O4 by MnO and 16 to 21 mol percent of ZnO. The assistant components are at least one kind from SiO2, CaCO3, V205 and Nb2O5. Total weight based on the main components is that SiO2 is0.002 to 0.01 wt percent, CaCO3 is 0.01 to 0.08 wt percent, V205 is 0.01 to 0.07 percent, and Nb2O5 is 0.01 to 0.07 percent. The broadband high impedance MnZn ferrite material has DC resistivity larger than 103 omega meter, curie temperature higher than 115 degrees centigrade and 2000 plus or minus 20 percent initial permeability. Moreover, the low frequency impedance of the material is larger than the common NiZn ferrite material, the high frequency impedance thereof is equal to the common NiZn ferrite material and the material does not contain expensive raw material NiO. The invention further provides the manufacture method of the broadband high impedance MnZn ferrite material, which comprises the steps of mixing, drying, preburning, ball-milling, granulation, molding, sintering and thelike.

The invention discloses a joint inversion method based on magnetotelluric and DC resistivity data, and the method comprises the steps: determining an inversion region according to observation data, carrying out the subdivision to obtain an initial grid, and setting an initial value of an inversion parameter vector; performing Gaussian-Newton inversion iteration based on the current value of the inversion parameter vector to calculate a model change amount and a linear search step length, and then calculating an iterative update value of the inversion parameter vector; judging whether an inversion termination condition is met or not, and if not, carrying out next iteration; if so, judging whether a progressive grid inversion termination condition is reached or not, and if so, ending the inversion; and if not, carrying out refined subdivision on the grid cell, updating the inversion parameter vector value, and returning to carry out Gauss-Newton inversion iteration until inversion is finished. According to the invention, a joint inversion technology of inversion grid adaptive adjustment is researched and developed, the problem of multiplicity of solutions of joint inversion interpretation of a magnetotelluric method and direct current resistivity data is effectively reduced, and the joint interpretation accuracy is improved.

The invention provides a background grid adaptive segmenting method in a DC resistivity no-unit method. The method comprises the following steps of determining distribution condition of medium, abnormal member, landform, electrode and the like in a two-dimensional ground electric model, establishing a DC resistivity no-unit method calculating domain, and utilizing an irregularly distributed node discrete ground electric model; covering the calculating domain by means of a small number of rough and simple initial quadrangular grids, setting a control value which guides adaptive segmentation, and performing adaptive segmentation by the background grid according to the control value and a node distribution condition; arranging ng Gaussian integration points xg in each background grid, and obtaining a no-unit method equation set of the region; solving the equation set for obtaining a node electric field value, and calculating the vision resistivity parameter of a viewing point. The methodcan be based on any node distribution discrete model. High adaptability for any complicated ground electric model is realized. The background grid adaptive segmenting method improves value stability and computing efficiency in routine DC resistivity no-unit method forward calculation.

The invention discloses a preparation method of a manganese zinc soft magnetic ferrite, and belongs to the technical field of ferrite material preparation. Orange peels and iron powder are reduced ina sulfuric acid solution for reduction leaching to form manganese dioxide in pyrolusite so as to obtain a leaching agent containing manganese ions, and manganese dioxide is added into the leaching agent, and the manganese zinc soft magnetic ferrite is obtained through ball-milling, mold pressing and sintering, so that the direct current electrical resistance is extremely high, the generation of aneddy current can be reduced, the loss of a magnetic core is reduced, and the saturation flux density of the soft magnetic ferrite is improved; during sintering, the sintering temperature is raised toa relatively high temperature, and then the sintering temperature is deceased to a relatively low temperature, the temperature is preserved for a period of time, in the period, crystal particles arefree of obvious growth, the sintered and obtained soft magnetic ferrite has uniformer and finer particles and relatively high density by controlling the change of the temperature, and the Curie temperature of the soft magnetic ferrite is increased, so that the manganese zinc soft magnetic ferrite has high saturation flux density and abroad application prospects.

A planar metal antenna mounted on a semiconductor body and incorporating an active circuit element, for example a diode, integrated in the path of the antenna. Connection between the antenna metal and a peripheral contact is provided by a connecting link of resistive sheet material sub-divided, by voids or by inclusions of high resistive material, into a number of conductive tracks each of width and spacing of dimension small compared with the width of the antenna. The link thus exhibits an effectively high sheet resistivity at high frequency—i.e. at a frequency at or near to the frequency of antenna resonance and thus affords effective hf isolation between the antenna and the contact. At the same time, at dc and at intermediate frequency, a relatively low resistance path is afforded for bias and for extraction of IF signal. The number, width and spacing of the tracks may be varied with distance from the antenna metal to minimize the dc resistivity. Thus the track density may be graded; the link may be comprised of several sections each of different track density. Alternatively, the track density may be made a tapered function of distance from the antenna metal by variation of the size and density of voids or high resistivity inclusions. The connection may be formed of material overlying the semiconductor body. Alternatively, it may be defined in the semiconductor body by dopant implant.

The invention discloses a manufacturing method of a high-conductivity high-strength aluminum alloy wire for a smart power grid. The method includes the steps that firstly, an aluminum alloy continuous casting and continuous rolling unit with an on-line purification system is used for conducting machining to obtain a supersaturated aluminum alloy rod; secondly, natural aging is conducted on the supersaturated aluminum alloy rod; thirdly, cold drawing is conducted on the aluminum alloy rod obtained in the second step to form an aluminum alloy wire; fourthly, the aluminum alloy wire is placed into a continuous aging oven for manual aging strengthening treatment; and fifthly, multiple wires obtained through the fourth step are concentrically twisted, and the performance of the twisted high-strength aluminum alloy wire meets the conditions that the tensile strength is not smaller than 340 MPa, the elongation is not smaller than 5.0%, the 20 DEG C direct current resistant rate is not higher than 0.031927 ohm.mm2/m, and the electric conductivity is not smaller than 54.0%IACS. The wire obtained through the manufacturing method has the characteristics of being high in tension-weight ratio, good in electric conductivity and high in overload resistance; the process is simple; and the method is suitable for industrial production, can greatly save line construction cost and operation cost when applied to the smart power grid field, and has excellent economic benefits.

The invention discloses a broadband high-impedance manganese-zinc ferrite material. The material comprises a main component and an auxiliary component, the main component comprises Fe2O3, ZnO and Mn3O4 (in terms of MnO), and the auxiliary component is selected from at least one of SiO2, CaCO3, Nb2O5, Co2O3 and TiO2. The manganese-zinc ferrite material has the direct-current resistivity of above 1000 ohm.m, the Curie temperature of above 150 DEG C, the normal-temperature saturation flux density of above 420 mT and the initial permeability of above 2000, and also has the characteristic of high impedance in a broadband range of 0.01-700 MHz.

A method is disclosed for generating an image of earth formations penetrated by a wellbore. The method includes generating an initial model of the earth formations using formation resistivity measured by a direct current signal. A response to the initial model of an instrument used to make the direct current resistivity measurements is calculated. The calculated response is compared to the measurements of resistivity. The model is adjusted, and the calculating and comparing are repeated until a difference between the calculated response and measurements reaches a minimum. The adjusted model is refined based on resistivity measurements made using an electromagnetic measuring instrument, and the refined model is constrained using acoustic velocity measurements.

The invention relates to a composite metal wire and a manufacturing method. The composite metal wire is formed by compositing a core body and a coating layer, and the coating layer is made of copper and particularly the copper with the weight purity ranging from 99.90% to 99.98%; the core body is an iron alloy comprising, by weight, 35% of copper, 55% of iron and 10% of aluminum; the thickness of the coating layer is from one fourth to one second the radius of the wire. The direct-current resistivity of the composite wire made of the copper-coated iron alloy is lower than that of a copper-coated steel wire, signal transmission is ensured, the requirement for the carrying capacity when the composite metal wire is applied to the electron industry is met, and the loss of the composite metal wire is smaller than that of the copper-coated steel wire.

The invention discloses a broadband high-impedance manganese-zinc ferrite material. The material comprises a main component and an auxiliary component, the main component comprises Fe2O3, ZnO and Mn3O4 (in terms of MnO), and the auxiliary component is selected from at least one of SiO2, CaCO3, Nb2O5, Co2O3 and TiO2. The manganese-zinc ferrite material has the direct-current resistivity of above 2,000 ohm.m, the Curie temperature of above 180 DEG C, the normal-temperature saturation magnetic induction intensity of above 430mT and the initial magnetic conductivity of above 1000, and also has thecharacteristic of high impedance in a broadband range of 0.01-700 MHz.

The invention discloses a MnZn ferrite material with high frequency and high impedance. The MnZn ferrite material is composed of main components and auxiliary components. The MnZn ferrite material is characterized in that counted by oxides according to molar percentage, the main components comprise 46.0-54.0mol% of Fe2O3, 25.0-27.0mol% of MnO and 19.0-21.0mol% of ZnO; counted by oxides according to percentage by weight, based on the total weight of the main components, the auxiliary components comprise at least one of 0.03-0.08wt% of TiO3, 0.03-0.08wt% of CaCO3 and 0.03-0.08wt% of V2O5. At 100MHz, the MnZn ferrite material has direct current resistivity greater than 200.Omega m, a Curie temperature of 25 DEG C and initial magnetic conductivity greater than or equal to 7000.

The invention discloses a numerical simulation method for a three-dimensional direct current resistivity method, which comprises the following steps of: setting direct current method exploration area and background resistivity parameters, three-dimensional anomalous body distribution range and resistivity parameters, calculating current density, performing two-dimensional discrete Fourier transform, calculating wave number domain abnormal potential, performing two-dimensional inverse Fourier transform, performing iterative convergence judgment and the like. And efficient and high-precision numerical simulation of three-dimensional direct current electric method exploration is realized. The problem that fine inversion of large-scale direct-current electric method data cannot be met due to the fact that the data size is large, the storage requirement is high and the calculation time is slow when a large-scale model is calculated in current direct-current electric method exploration numerical simulation is solved, and fine inversion and explanation of direct-current electric method measured data under field complex terrains or underground complex structures can be achieved.

The invention provides a boundary treatment method of coupling a direct-current resistivity element-free method with a finite element method. The boundary treatment method includes the steps of building a small-range element-free method area omega 1 to a two-dimension geoelectric model, calculating by the element-free method for the area, covering the element-free method area omega 1 with regularly distributed rectangular or parallelogram background grid to obtain an element-free method equation set of the area; subdividing the periphery of the element-free method area omega 1 by finite element method grid which is capable of rapid expansion, building a large-enough finite element method area omega 2 which meets requirements of first class of boundary conditions, calculating by the finiteelement method to obtain a finite element equation set of the area; combing the equation sets of the two areas and solving to obtain parameter of the apparent resistivity of an observation point. Themodels can be discrete on the basis of arbitrary node distribution by the method, the boundary treatment method has high adaptability to any complex geoelectric models, and calculation efficiency of forward modeling in the conventional direct-current resistivity element-free method is improved since boundary treatment is carried out by means of the finite element method.