Junxia Gao

• Beijing University of Technology

As geological exploration progresses in depth and scope, the distance between transmitting and receiving systems also increases. Consequently, the synchronization of time between the two becomes an increasingly critical issue. In response, this paper presents a proposed design for a time synchronization system that is suitable for use between trans...

In order to effectively suppress the higher harmonics contained in the output voltage of high-power electromagnetic transmitter, the waveform expression of the output voltage of bipolar pulse width modulation (SPWM) circuit is derived, which can accurately obtain the fundamental wave and each harmonic content in the inverter bridge transmission vol...

This paper takes the time-domain aeromagnetic system as the research object and uses the finite element software COMSOL Multiphysics 6.0 to establish the three-dimensional system model. By comparing the COMSOL Multiphysics forward simulation solution with the one-dimensional numerical solution, it verifies that the COMSOL software meets the simulat...

This paper touches on a sine wave transmitting mode being designed applicable to multichannel high-power electromagnetic transmitters, well explaining the design scheme and working principle of each module. With FPGA as the core to build the hardware platform and DSP as a bridge to the cooperation between the upper computer and the FPGA lower compu...

The demand for phased array antennas increases not only for the traditional military industry but also in commercial areas such 5G mobile network platforms, Internet of Things (IoT), and satellite communication applications. In this paper, a phased array with beam scanning function is designed based on arithmetic phase difference between array elem...

This paper designs a three-axis closed-loop fluxgate system for geophysical prospecting, which contains excitation, induction, and feedback circuits. By analyzing and comparing the noise levels before and after the system operation, it is concluded that the main factor affecting the fluxgate performance is the excitation circuit noise. By analyzing...

With the continuous development of integrated electronics and the increasing demand for downhole resource exploration, it has become important to develop a small size, high temperature resistant, high-performance digital fluxgate sensor. Due to the strict size limitation of downhole exploration equipment, some high-temperature devices are generally...

The high operating voltage and switching speed of silicon carbide (SiC) MOSFETs have significant impacts on parasitic elements. This leads to a limitation in the performance of the devices. Especially in the bridge-leg configuration, the coupling of the parasitic elements, in the upper and lower bridge-legs, produces knock-on effects, which complic...

The fluxgate sensor uses the nonlinear characteristics of soft magnetic materials to measure the geostationary magnetic field, which has the characteristics of high sensitivity, wide magnetic measurement range and easy portability, and is widely used in geological exploration, navigation, space technology and other fields. In this paper, the resear...

This paper presents a new variable-frequency phase-shift control method to improve the conversion efficiency for a high-power wide-range converter based on a phase-shifted full-bridge (PSFB) converter. The proposed converter can adjust the switching-frequency according to the load power to make the input impedance be inductive. The main switches of...

An electromagnetic transmitter transmits electromagnetic waves with variable frequencies to the ground to obtain underground structure information and the distribution of mineral resources. In order to improve the power factor and reduce the volume and weight of the transmitter, a novel transmitter topology with pulse width modulation (PWM) rectifi...

Marine-controlled source electromagnetic transmitter is an important equipment for the investigation of marine geology and exploration of oil, gas, and mineral resources in recent years. There are some problems from the direct current–direct current (DC–DC) converter of high power marine transmitter, the load is light, when the output current is re...

To improve the efficiency of the liquid metal magnetohydrodynamic (LMMHD) generator, a new type of magnet structure of LMMHD system is designed in paper. The internal magnetic gathering capability is enhanced by imitating the arrangement of the Halbach array magnet. The magnetic induction intensity of conventional magnetic channel, Halbach magnet c...

A hydrothermal electrocatalytic oxidation (HTECO) method is adopted to treat the biorefractory and toxic 2,4-dichlorophenoxyacetic acid (2,4-D) herbicides wastewater on nano-Pt/Ti electrode in the existence of H2O2. Comparisons for the removal of 2,4-D and total organic carbon (TOC) have been carried out between HTECO with individual electrochemica...

An ultrasound-enhanced electrochemical oxidation process with boron-doped diamond anodes is adopted and used for removing bisphenol A. The reaction activity and mechanism is evaluated and explained through experimental and theoretical methods. The structure and stability of the anode surface are illustrated and the electrochemical oxidation channel...

A novel SnO2-Sb/CA electrode, possessing high surface area, strong adsorption capacity, good electrical conductivity and electrocatalytic activity, was firstly proposed for ultrasonic electrochemical oxidation (US-EC) of persistent high concentration perfluorooctanoate (PFOA) in this study. The optimal calcination temperature for sinking micro-size...

A method for in situ improvement of the electro-Fenton (EF) oxidation process using microwave radiation was proposed. The microwave enhanced electro-Fenton (MW-EF) degradation of azo dye wastewater with boron-doped diamond (BDD) anode was carried out in a continuous flow system under atmospheric pressure. The activation effects of microwave were st...

The opaque methylene blue (MB) dye wastewater hard to be degraded directly by photocatalytic (PC) oxidation was successfully decomposed by a new two-step process, in which electrocatalytic (EC) pre-oxidation was followed with photoelectric synergistic catalytic (PEC) oxidation. The SnO2/TiO2 NTs electrode was used as the anode, which simultaneously...

Aqueous aromatic hydrocarbons are chemically stable, high toxic refractory pollutants that can only be oxidized to phenols and quinone on either Pt or traditional PbO(2) electrodes. In this study, a novel method for the electrochemical incineration of benzene homologues on superhydrophobic PbO(2) electrode (hydrophobic-PbO(2)) was proposed under mi...

In this paper, a synergistic combination of the biochemical treatment and electrochemical oxidation (SBEO) of landfill leachate with sectional treatment on a boron-doped diamond (BDD) electrode is proposed. The first stage involves the synergistic system of biochemical treatment and electrochemical oxidation. Then, the second stage is followed by i...

A new two-step process involving the electrocatalytic (EC) pre-oxidation and the following photoelectrocatalytic synergistic (PEC) oxidation is proposed to treat the high concentration and high-chroma methyl orange dye wastewater, which cannot be degraded by photocatalytic oxidation (PC) directly. The SnO(2)/TiO(2)-NTs/Ti electrode simultaneously p...

A novel integrated biological and electrochemical oxidation (BEO) process was proposed for the treatment of biorefractory pesticide wastewater with high toxicity. An acetamiprid solution of 1000 mg L−1 was used as the target pollutant. Its biodegradability in terms of biochemical oxygen demand in a 5-d test period (BOD5)/total organic carbon (TOC)...

A modified boron-doped diamond (BDD) electrode was prepared by evenly assembling Sb-doped SnO2 nanoparticles on the BDD surface, which possesses excellent electrocatalytic performance and is more suitable to degrade the pollutants. The growth of Sb-doped SnO2−NPs was controlled using micelles of the block copolymer surfactant and homogeneous precip...

A novel PbO(2) electrode with a high oxygen evolution potential (OEP) and excellent electrochemical oxidation performance is prepared to improve the traditional PbO(2) electrode, which is modified by changing the microstructure and wetting ability. A middle layer of TiO(2) nanotubes (NTs) with a large surface area is introduced on Ti substrate, and...

Remarkable enhancement in degradation effect is achieved at in situ activated boron-doped diamond (BDD) and Pt anodes with different extent through electrochemical oxidation (EC) of 2,4-dichlorophenoxyacetic acid (2,4-D) with microwave (MW) radiation in a flow system. Results show that when EC is activated with MW radiation, the complete mineraliza...

In this study, an in situ microwave activated platinum electrode was developed for the first time to completely incinerate the azo dye simulated wastewater containing methyl orange. The experiments were carried out in a circulating system under atmospheric pressure. Azo bond of methyl orange was partly broken on Pt, certain decoloration was reached...

The enhancement on degradation of two typical organic pollutants, phenol (Ph) and phthalic acid (PA) on boron-doped diamond (BDD) electrode is particularly investigated in this study. Results show that ultrasound (US) has remarkable influence on electrochemical (EC) oxidation of the two pollutants including degradation efficiency, EC oxidation ener...

A method for improving the oxidation ability of the electrode is proposed by using microwave activation in electrochemical oxidation. The electrochemical degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) with microwave radiation (MW-EC) was carried out in a continuous flow system under atmospheric pressure. In 3 h the removal of COD, ACE (avera...