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Traditional single-ended fault location method is influenced by the fault resistance and the remote in feed, which reflects as the two equations built by fault phase have four unknowns. And in the grid-connected converter system, the weak feedback characteristic further reduces the performance of the method. To solve it, a single-ended fault location method based on control and protection coordination is proposed in this paper. First, using the high controlled-ability of the converter, the control strategy for fault ride-through (FRT) operation is divided into two stages by switching control modes. Then, according to the electrical quantities under two stages, four uncorrelated equations can be established, and the equations still have four unknown parameters. The fault distance can be calculated by solving them. The simulation results show that the proposed method has high accuracy and is immune to fault resistance and fault location, it solves the problem of insufficient equations in principle.

Accurate fault location plays an important role in the fault clearance of the transmission line. However, because of the influence caused by fault resistance and the remote end system, there are four unknowns in the two equations built by the fault phase. Thus, the equations cannot be solved. In this paper, a single-terminal fault location method for transmission lines integrated by the inverter-type source is proposed. For a single-phase to ground fault or phase-to-phase fault, due to the specific control strategy, the equivalent positive and negative-sequence impedances of the converter are unequal in most cases. However, the positive and negative-sequence impedances of other elements are approximately equal, and the boundary condition at the fault branch is definite. Combining the boundary condition and the sequence impedance difference, two uncorrelated equations can be built. Substituting them to the equations built by the fault phase, the fault location can be calculated accurately. And the influence caused by fault resistance and the remote end system is eliminated. The simulation results show that the proposed method can achieve fault location accurately. Moreover, it has higher reliability and is independent of control strategy, fault distance and fault resistance.

We synthesized a PbO2-coated electrode consisting of three layers, with Pb–0.6%Sb alloy as the substrate, α-PbO2 as the intermediate layer, and the outermost β-PbO2-Co3O4@C as the active layer for boosting OER activity.

In the presence of magnetic field, reducing the loss in temperature coefficient of resistance (TCR) and increasing metal−insulator transition point (TMI) to room temperature are the most important concerns for the application of perovskite manganites in high−precision thermistors. Based on emerging evidence, relevant factor to address these problems lies in the interaction between Jahn−Teller (JT) distortion and magnetic field, which results in spin−orbital coupling (SOC) effect and significantly influences TCR and TMI. In this work, we studied the magnetic field induced SOC effect in polycrystalline La1−xCaxMnO3 (x = 0.225–0.45) materials synthesized via sol−gel technique. Compounds undergo the JT distortions with increasing Ca dopant content, and the most pronounced distortion of 0.0144 at x = 0.40 is correlated with a basal−plane distortion mode. All samples exhibit TMI values between 262 K and 288 K, indicating the enhancement of doping−induced double−exchange interaction. In the magnetic field of 1 T, SOC effect sufficiently suppresses the deterioration of TCR caused by deficient magnetization in La0.6Ca0.4MnO3 to a value of 2.9%·K−1 at room temperature (287 K).

High oxygen evolution overpotential and low corrosion resistance are the main challenges for oxygen evolution materials in acidic media. In this study, a novel composite material, Ti/TiO2-NTs/PbO2–CNTs–MnO2, with high oxygen evolution electrocatalytic activity was successfully prepared. First, TiO2 nanotubes (TiO2-NTs) were synthesized in situ on a Ti sheet via anodization and used as an intermediate layer. Subsequently, the adhesion and conductivity of the TiO2-NTs layer were increased through additional anodization, annealing, and electrochemical reduction. Finally, PbO2 was electrodeposited with a constant current in a lead acetate medium and doped with carbon nanotubes (CNTs) and MnO2. The surface morphology, phase composition, and electrochemical performance of the composite materials were investigated. Notably, in an acidic electrolyte (150 g/L H2SO4), Ti/TiO2-NTs/PbO2–CNTs–MnO2 exhibited good stability (30 h) and a low oxygen evolution overpotential of 410 mV at 50 mA/cm2, which is almost equivalent to that of precious metals (RuO2 and IrO2) and 499 mV lower than that of the industrial Pb–0.76 wt% Ag alloy. The outstanding performance is mainly attributed to the high aspect ratio of the TiO2-NT structure, synergistic effects of the active particles, and inherently good electrochemical properties of the active particles. Therefore, this study provides a new synthetic route for oxygen evolution materials in acidic media.

In addition to complex preparation and low-yield syntheses, attaining high energy density while maintaining high power density remains a significant challenge for supercapacitor applications in the field of energy storage. Herein, two-dimensional (2D) nickel-based metal-organic framework (NiMOF) nanosheets are grown around carbon nanotubes (CNTs) to form NiMOF/CNTs composite, which is synthesized

The polycrystalline La1−xCaxMnO3 ceramics exhibit good electromagnetic performance, i.e., high temperature coefficient of resistivity (TCR), which can be tuned flexibly with respect to structures. Unfortunately, the magnetic field applied to these materials causes a massive decrease in TCR, which hinders their practical applications. In this study, polycrystalline ceramic La1−xCaxMnO3:Ag0.2 was fabricated by sol–gel and solid–phase doping methods, and subsequently vast TCR was obtained in the magnetic field for ceramic with x = 0.2. For this polycrystalline material, high value of TCR (58.65%·K−1, 62.00%·K−1) could be maintained with or without magnetic field with metal–insulator (M − I) transition temperature near room temperature range. Extremely high value of TCR in the presence of magnetic field is attributed to the spin–spin coupling effect, which is beneficial to the sensitivity of M − I transition, generating vast TCR in the magnetic field. Overall, these findings provide new prospects for future applications in infrared bolometers.

In this work, fine Ti4O7 powders with many defects were prepared by ball milling and sonication treatments and used as a support material to load Pd nano-particles (Pd NPs). The electrocatalytic performance of this catalyst (Pd/Ti4O7(F)) towards oxygen reduction reaction (ORR) was investigated. It was found that as compared with Pd NPs supported on commercial Ti4O7 (Pd/Ti4O7(C)), Pd/C, and commercial Pt/C, the Pd/Ti4O7(F) catalyst exhibited the best catalytic activity and excellent durability in alkaline solution. According to X-ray photoelectron spectra (XPS), electron paramagnetic resonance (EPR) spectra, and conductivity measurement results, the strong metal-support interactions (SMSIs) and high conductivity induced by abundant oxygen vacancies and disorder layers in the treated Ti4O7 support play a vital role in promoting the ORR activity of this electrocatalyst. These provide a new strategy for the design of high-performance ORR catalysts.

The environment perception algorithm in autonomous driving is trained in the source domain, leading to domain drift and reduced detection accuracy in the target domain due to shifts in background feature distribution. To address this issue, a domain adaptive object detection algorithm based on feature uncertainty is proposed, which can improve the detection performance of object detection algorithms in unlabeled data. Firstly, a local alignment module based on channel information is proposed, which can obtain the model’s uncertainty about different domain data based on the feature channels obtained through the feature extraction network, achieving adaptive dynamic local alignment. Secondly, an instance-level alignment module guided by local feature uncertainty is proposed, which can obtain the corresponding instance-level uncertainty through ROI mapping. To improve the domain invariance of bounding box regression, a multi-class, multi-regression instance-level uncertainty alignment module is proposed, which can achieve spatial decoupling of classification and regression tasks, further improving the model’s domain adaptive ability. Finally, the effectiveness of the proposed algorithm is validated on Cityscapes, KITTI, and real vehicle data.

Flexible touch-sensing devices have attracted extensive attention in wearable electronics and human-machine interaction. The ionic touch-sensing hydrogels are ideal candidates for these scenarios, but the absorbed water evaporates easily from the hydrogel, reducing their working time and stability. Herein, we propose a touch-sensing fabric system composed of non-woven cellulose fabrics as a sheath shell layer encapsulated with a hydrogel filling layer. The resultant touch-sensing fabric has a super-thin structure (1 mm) and exhibits a low detecting threshold (50 Pa), high durability (100k times), strain/pressure insensitivity and extremely high touch positioning accuracy. In the proof of concept, a smart touch-sensing glove is equipped with our fabric, which can execute human-computer interaction as a flexible touch-sensing device.

The high oxygen evolution overpotential of the Pb–Ag anode is one of the main reasons for the high energy consumption in Zn electrowinning. PbO2, owing to its high conductivity, good corrosion resistance and low cost, is widely used as an excellent coating material. In present research, a novel composite Ti/TiO2-NTs/PbO2 material was synthesized through a facile anodization, annealing, electrochemical reduction and galvanostatic deposition. The surface morphology, internal structure and the mechanisms of TiO2-NTs enhancing electrochemical performance were discussed. The results show that the self-organized high aspect ratio TiO2-NTs with diameter of ∼120 nm and length of ∼8 μm were obtained on Ti substrate. The Ti/TiO2-NTs/PbO2 composite material exhibits excellent oxygen evolution performance and good stability in Zn electrowinning simulation solution (50 g L−1 Zn2+, 150 g L−1 H2SO4) at 35 °C. Its oxygen evolution overpotential is only 630 mV under current density 50 mA cm−2, which is 332 m lower than that of Pb-0.76 wt% Ag (η = 962 mV) and only increases 22 mV after 5000 cycles of CV scanning. Its outstanding electrochemical performance is mainly ascribed to the introduction of TiO2-NTs in Pb(CH3COO)2 media since it refines the crystal grains, increases the electrochemical surface area, greatly reduces the charge transfer resistance (25.4 Ω cm2 to 2.337 Ω cm2) and enhances corrosion resistance. Therefore, the Ti/TiO2-NTs/PbO2 material prepared in Pb(CH3COO)2 medium may be an ideal anode for Zn electrowinning.

In the present work, a novel Pb-0.6%Sb/α-PbO2/β-PbO2 composite electrode with quantitatively phases of α or β-PbO2 was obtained by electrodeposition in methanesulfonic acid (MSA) and further investigated in novel flow battery. The physicochemical properties of lead dioxide were analyzed by anodic polarization curves, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and Tafel curves. Results showed that the selection of temperature ranges was found to cause a quantitative difference in the formation of α/β-PbO2 phases, as it made interval effects on the overpotential that was the primary control condition to affect transfer proces.The precise conditions of obtaining α or β-PbO2 phases by varying temperatures were confirmed and samples were prepared to be tested in long-period galvanostatic electrolysis. By comparing, the electrode (deposition time-α&β: 2 h&2 h) showed the best physicochemical properties, which could effectively improve the energy storage and extend the lifetime (63.6 h) compared with the traditional lead dioxide electrodes (24.5 h) in novel flow battery.

Chemical looping technology enables achievement of the simultaneous feedstock conversion and product separation without additional processes via circulating solid intermediates (so-called oxygen/ni...

The high energy consumption during zinc electrowinning is mainly caused by the high overpotential of the oxygen evolution for Pb–Ag alloys with strong polarization. The preparation of new active energy-saving materials has become a very active research field, depending on the synergistic effects of active particles and active oxides. In this research, a composite material, α(β)-PbO2, doped with Co3O4 and CNTs on the porous Ti substrate was prepared via one-step electrochemical deposition and the corresponding electrochemical performance was investigated in simulated zinc electrowinning solution. The composite material showed a porous structure, finer grain size and larger electrochemical surface area (ECSA), which indicated excellent electrocatalytic activity. Compared with the Pb–0.76 wt% Ag alloy, the overpotential of oxygen evolution for the 3D-Ti/PbO2/Co3O4–CNTs composite material was decreased by about 452 mV under the current density of 500 A m−2 in the simulated zinc electrowinning solution. The decrease in the overpotential of oxygen evolution was mainly ascribed to the higher ECSA and lower charger transfer resistance. Moreover, it showed the lowest self-corrosion current density of 1.156 × 10−4 A cm−2 and may be an ideal material for use in zinc electrowinning.

NiO, Ni–Co–Mn–Ox and NiO/Ni–Co–Mn–Ox on nickel foam substrates were prepared via a chemical bath deposition–calcination. The thermodynamic behavior was observed by TG/DTA. The chemical structure and composition, phase structure and microstructures were tested by XPS, XRD, FE-SEM and TEM. The electrochemical performance was measured by CV, GCD and EIS. The mechanism for formation and enhancing electrochemical performance is also discussed. Firstly, the precursors such as NiOOH, CoOOH and MnOOH grow on nickel foam substrates from a homogeneous mixed solution via chemical bath deposition. Thereafter, these precursors are calcined and decomposed into NiO, Co3O4 and MnO2 respectively under different temperatures in a muffle furnace. Notably, NiO/Ni–Co–Mn–Ox on nickel foam substrates reveals a high specific capacity with 1023.50 C g−1 at 1 A g−1 and an excellent capacitance retention with 103.94% at 5 A g−1 after 3000 cycles in 2 M KOH, its outstanding electrochemical performance and cycling stability are mainly attributed to a porous sheet–sheet hierarchical nanostructure and synergistic effects of pseudo-capacitive materials and excellent redox reversibility. Therefore, this research offers a facile synthesis route to transition metal oxides for high performance supercapacitors.

The nanoscale size and controllable memristance of Memristor (MR) have shown evident superiorities for structuring new integrated circuits with different functions. With regards to the reported MR based filters, their cut-off frequencies could be hardly hot-line controlled on purposes. In this paper, by using the boundary values of memristance, a method for hot-line adjusting cut-off frequencies is newly proposed by inputting a preset DC voltage together with the to-be-filtered signal, without the requirement of extra memristance write circuits, which is hence beneficial for integrated implementation. The floating MR emulator is firstly presented and the saturation operation of its memristance is interpreted. A family of MR based low-pass filters with controllable cut-off frequency are proposed by combining the connection nodes of a memristive circuit network Z with the op amp. Two circuits of the low-pass filter family are chosen for demonstration, and the cut-off frequency and passband gain are calculated. Square and sinusoidal voltage signals are used to test the performance of the proposed low-pass filter family. Both the simulation and experimental results show that the proposed filters can achieve cut-off frequency adjustment with good filtering performance.

The LLC-type resonant dual-active-bridge (LLC-DAB) DC-DC converter with a high voltage gain, high power density, and low backflow power has attracted increasing attention in recent years. However, its soft-switching and backflow power problems are still not solved, so the improvements to these problems are studied in this paper. Based on the dual phase shift (DPS) modulation method, the operating characteristics are analyzed, and a soft-switching and no backflow power modulation curve is established based on the voltage-current time-domain characteristics. On this basis, a soft-switching and no backflow power optimized control method based on DPS modulation is proposed to achieve soft-switching operation and eliminate backflow power. Due to the complex time-domain characteristics of the resonant tank voltage and current, the relationship between the phase shift ratios is fitted and optimized with this method based on the soft-switching and no backflow power characteristic curve, and the optimized results of the phase shift ratio under different operating conditions are obtained. The simulation results indicate that the soft-switching operation of the LLC-DAB converter can be achieved with the optimized control method proposed in this paper, and the backflow power is effectively eliminated.

The conventional Pb-Ag alloy possesses a high oxygen evolution reaction overpotential, poor stability, and short service life in acidic solutions, making it an unsuitable sort of anode material for the zinc electrowinning process. Therefore, a layered carbon-covered cobalt tetroxide (Co

The oxygen evolution reaction kinetics in industrial zinc electrowinning is sluggish, resulting in low electrocatalytic activity and substantial energy expenditure (about one-third of energy was wasted due to the strong polarization effect). Herein, the paper described a core-shell structured MnCo

In the present work, a novel Pb-0.6%Sb/α-PbO2/β-PbO2-MnO2 composite electrode with high electrocatalytic activity was obtained by electrodeposition in methanesulfonic acid and further investigated in the electrochemical degradation of alizarin yellow R(AYR) wastewater. The selection of temperature ranges was found to cause a quantitative difference in the formation of α/β-PbO2 phases. In this way, both phases were simultaneously electrodeposited in the same methanesulfonic acid, and electrodes with corresponding proportions of phases were fabricated. Furthermore, performance tests indicated that composite electrodes with the most appropriate corresponding proportions of phases co-deposited with proper amount of MnO2 could obviously improve the COD removal efficiency and degradation efficiency of AYR to 78.1% and 80.3%. They also showed commendable recyclability and fine economic applicability. Ultimately, the paper proposed a proper electrocatalytic degradation pathway of AYR based on the identification of the major intermediate products. The results proved that MnO2-co-doped composite electrodes had more promising application potential in the electrocatalytic degradation of AYR wastewater.

A new alkaline pressure oxidative leaching process (with NaNO3 as the oxidant and NaOH as the alkaline reagent) is proposed herein to remove arsenic, antimony, and lead from bismuth-rich and arsenic-rich lead anode slime for bismuth, gold, and silver enrichment. The effects of the temperature, liquid-to-solid ratio, leaching time, and reagent concentration on the leaching ratios of arsenic, antimony, and lead were investigated to identify the optimum leaching conditions. The experimental results under optimized conditions indicate that the average leaching ratios of arsenic, antimony and lead are 95.36%, 79.98%, 63.08%, respectively. X-ray diffraction analysis indicated that the leaching residue is composed of Bi, Bi2O3, Pb2Sb2O7, and trace amounts of NaSb(OH)6. Arsenic, antimony, and lead are thus separated from lead anode slime as Na3AsO4· 10H2O and Pb2Sb2O7. Scanning electron microscopy and energy-dispersive spectrometry imaging revealed that the samples undergo appreciable changes in their surface morphology during leaching and that the majority of arsenic, lead, and antimony is removed. X-ray photoelectron spectroscopy was used to demonstrate the variation in the valence states of the arsenic, lead, and antimony. The Pb(IV) and Sb(V) content was found to increase substantially with the addition of NaNO3.

CeO2–Fe2O3 mixed oxides are very attractive as catalysts for catalytic oxidation. Herein, we report the structural dependence of the Ce1–xFexO2−δ catalysts for CH4 combustion and CO oxidation via c...

Electrochemical decomposition of water to produce oxygen (O2) and hydrogen (H2) through an anodic oxygen evolution reaction (OER) and a cathodic hydrogen evolution reaction (HER) is a promising green method for sustainable energy supply. Here, we demonstrate that cauliflower-like S-doped iron microsphere films are materials that can efficiently decompose water as an electrocatalyst for the oxygen evolution reaction. FeSx films are prepared by a simple one-step electrodeposition method and directly grow on copper foam from a deep eutectic solvent, ethaline (mixture of choline chloride and ethylene glycol), as a durable and highly efficient catalyst for the OER in 1.0 M KOH. The prepared FeSx/CF, as an oxygen-evolving anode, shows remarkable catalytic performance toward the OER with a moderate Tafel slope of 105 mV dec−1, and require an overpotential of only 340 mV to drive a geometrical catalytic current density of 10 mA cm−2. In addition, this catalyst also demonstrates strong long-term electrochemical durability. This study provides a simple synthesis route for practical applications of limited transition metal nano catalysts.

To further improve the capability of fault identification for protection and adaptive reclosing, a fault identification scheme based on a control and protection coordination strategy for a hybrid multi-terminal HVDC system is proposed. The protection principle for fault isolation is constructed based on the difference of the polarity characteristic of fault current between the fault line and non-fault line in the uncontrolled fault stage and fault current limiting stage. In the adaptive reclosing stage, an active fault identification scheme based on the amplitude distribution law of the injection signal along the line is proposed. Intensive simulation studies prove the fault identification scheme can identify the fault area in various fault scenarios and identify permanent faults to carry out adaptive reclosing.

In order to solve the problem that the long-time delay of traditional differential protection which has reduced the reliability of high voltage direct current line backup protection, consider the control strategies and response characteristics of the converter controller, a pilot protection for HVDC transmission line based on polarity characteristics of control signal deviation is proposed. By analyzing the fault characteristics of the converter control signal during the fault, drawn the conclusion that when the DC system occurs fault, from the converter dynamic regulation stage to the fault steady-state, the deviation of rectifier constant current control signal and the deviation of inverter constant current control signal will meet the positive polarity and the deviation of inverter constant extinction angle control signal will meet the negative polarity, but these polarity characteristics are not satisfied when the AC system occurs fault, therefore, the protection criterion is constructed. The simulation results show that the proposed backup protection principle has strong anti-transition-resistance ability and high reliability. Compared with the traditional differential protection, the proposed principle can reliably identify the internal fault from the converter dynamic regulation stage to the fault steady stage, which improves the reliability of the traditional HVDC line backup protection.

The high oxygen evolution overpotential of the Pb-Ag anode is one of the main reasons for the high energy consumption in Zn electrowinning. PbO