Fault Protection Based on the Ratio of Zero-sequence Current Projection Components for Low-resistance Grounding System

The electrical characteristics of a single-phase grounding fault in a low-resistance grounding system was aualyzed, and a fault protection scheme was proposed for low-resistance grounding systems according to the ratio of the zero-sequence current projection components. The primary line selection was performed according to the zero-sequence current projection method and then the phase difference value was used for the secondary judgment. The proposed protection scheme was verified by Matlab/Simulink. The simulation results show that the scheme has a certain ability to withstand transition resistance, which effectively improves the sensitivity of the ground fault protection

In Situ Coating on LiFePO 4 with Ionic Liquid as Carbon Source for High-Performance Lithium Batteries

LiFePO4/C materials were synthesized via an in situ coating on LiFePO4 with 1-butyl-3-methylimidazolium dicyanamide [BMIm][N(CN)2] as a carbon source. The electrode materials were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results revealed that 1–2 nm carbon films were successfully coated on the LiFePO4 particles. The electrochemical properties of LiFePO4/C composite were investigated by cyclic voltammetry (CV) curves, electrochemical impedance spectra (EIS), and electrochemical analysis. The test results showed that the LiFePO4/C composite possessed outstanding reversibility, cycle performance, and rate performance. The discharge capacities of LiFePO4/C were 161.5 mAh g−1 at 0.1 C and 143.6 mAh g−1 at 1 C, respectively. The excellent electrochemical properties of the LiFePO4/C electrode were mainly due to the thin, uniform, and highly graphitized carbon films

A Comparative Study on LiFePO\u3csub\u3e4\u3c/sub\u3e/C by In-Situ Coating with Different Carbon Sources for High-Performance Lithium Batteries

LiFePO4/C materials are synthesized via in-situ coating of LiFePO4 by using 1-butyl-3-methylimidazolium dicyanamide ([BMIm][N(CN)2]) and glucose as carbon sources, respectively. The structure characterization results indicate that the carbon sources have no effect on the LiFePO4 particles, but have remarkable influence on the coated carbon films. It is found that the [BMIm][N(CN)2] carbon source leads to ultrathin (1–2 nm), uniform and highly graphitized carbon films. Due to this unique structure, the electrode materials fabricated by using [BMIm][N(CN)2] exhibit a superior electrode reaction reversibility, a capacity retention of 160.6 mAhg−1 (1.47% decay rate) after 50 cycles and a specific discharge capacity of 143.6 mAhg−1 at 1C, which is much better than the performance of the electrode materials synthesized with glucose

Flotation kinetics of coal in the Inflatable Cyclonic Flotation Column

This paper mainly investigates the flotation kinetics of coal in the flotation column. The flotation tests were carried out in the Inflatable Cyclonic Flotation Column (ICFC) which consists of two parts, i.e., the inflatable flotation unit and the cyclone flotation zone. The flotation rates of −0.5 + 0.25 mm, −0.25 + 0.074 mm, and −0.5 + 0 mm size fractions of coal were obtained respectively with different aeration rates. Based on the first-order kinetics model, the fitting parameters of four kinds of traditional dynamic models for the experimental data were obtained by the MATLAB software. In addition, a new flotation kinetics model was developed to match the column flotation result. It was found that the flotation rate obviously increased with the increasing aeration rate independent of the size fraction. The second-order kinetics model was suitable for the −0.25 + 0.074 mm and −0.5 + 0 mm size fraction of coal. For the −0.5 + 0.25 mm size fraction, the correlation coefficient (R) of the new model was close to 1 and the Sum of Squares for Error (SSE) was close to 0, indicating that the new model fitted the flotation result very well

Theoretical and practical investigation into the use of a bio-inspired “click” mechanism for the flight motor of a micro air vehicle

Recently, flapping wing micro air vehicles have received great attention with the drive to make smaller and smaller devices. This paper describes a theoretical investigation and subsequent practical implementation of a specific type of flight motor structure for this type of micro air vehicle that uses a “click” mechanism to improve mechanical efficiency. Diptera, which may use the mechanism, are the inspiration for this work. It builds on previous research into the “click” mechanism, which has been studied both from the biological and engineering points of view. It is difficult to capture the important fine details using a simple analytical model; hence, a multi-body dynamic software is used to model the device and to aid the design of a large-scale prototype. Force–deflection curves of the structure and the displacement response are obtained numerically and experimentally. The experimental and numerical results compare reasonably well, enabling the model to be used for further development and potential miniaturization of the flight motor structure. In a practical device, asymmetry occurs in the up- and down-stroke. The effects of this asymmetry are compared with previous results from analytical models. It is found that asymmetry offers a marginal improvement.Published versio

A multi-vehicle longitudinal trajectory collision avoidance strategy using AEBS with vehicle-infrastructure communication

Shortening inter-vehicle distance can increase traffic throughput on roads for increasing volume of vehicles. In the process, traffic accidents occur more frequently, especially for multi-car accidents. Furthermore, it is difficult for drivers to drive safely under such complex driving conditions. This paper investigates multi-vehicle longitudinal collision avoidance issue under such traffic conditions based on the Advanced Emergency Braking System (AEBS). AEBS is used to avoid collisions or mitigate the impact during critical situations by applying brake automatically. Hierarchical multi-vehicle longitudinal collision avoidance controller is proposed to guarantee safety of multi-cars using Vehicle-to-Infrastructure (V2I) communication. High-level controller is designed to ensure safety of multi-cars and optimize total energy by calculating the target braking force. Vehicle network is used to get the key vehicle-road interaction data and constrained hybrid genetic algorithm (CHGA) is adopted to decouple the vehicle-road interactive system. Lower level non-singular Fractional Terminal Sliding Mode(NFTSM) Controller is built to achieve control goals of high-level controller. Simulations are carried out under typical driving conditions. Results verify that the proposed system in this paper can avoid or mitigate the collision risk compared to the vehicle without this system

DataSheet_1_A chromosome-scale genome assembly of Quercus gilva: Insights into the evolution of Quercus section Cyclobalanopsis (Fagaceae).docx

Quercus gilva is an ecologically and economically important species of Quercus section Cyclobalanopsis and is a dominant species in evergreen broad-leaved forests in subtropical regions of East Asia. In the present study, we reported a high-quality chromosome-scale genome assembly of Q. gilva, the first reference genome for section Cyclobalanopsis, using the combination of Illumina and PacBio sequencing with Hi-C technologies. The assembled genome size of Q. gilva was 889.71 Mb, with a contig number of 773 and a contig N50 of 28.32 Mb. Hi-C scaffolding anchored 859.07 Mb contigs (96.54% of the assembled genome) onto 12 pseudochromosomes, with a scaffold N50 of 70.35 Mb. A combination of de novo, homology-based, and transcript-based predictions predicted a final set of 36,442 protein-coding genes distributed on 12 pseudochromosomes, and 97.73% of them were functionally annotated. A total of 535.64 Mb (60.20%) of repetitive sequences were identified. Genome evolution analysis revealed that Q. gilva was most closely related to Q. suber and they diverged at 40.35 Ma, and Q. gilva did not experience species-specific whole-genome duplication in addition to the ancient gamma (γ) whole-genome triplication event shared by core eudicot plants. Q. gilva underwent considerable gene family expansion and contraction, with 598 expanded and 6,509 contracted gene families detected. The first chromosome-scale genome of Q. gilva will promote its germplasm conservation and genetic improvement and provide essential resources for better studying the evolution of Quercus section Cyclobalanopsis.</p