Research on Development and Application of Low-Voltage and High-Speed Power Line Communication Technology

Low-voltage and high-speed power line communication (PLC) technology, as the main means of communication construction, enables the masses to obtain higher quality services and has attracted more and more public attention. This paper is divided into four parts: the introduction of PLC technology, the application significance of low-voltage and high-speed PLC communication technology, the characteristics of PLC channel and the application and comparison of high-speed PLC technology

Open AccessArticle Optimal Water-Fertilizer Combinations for Efficient Nitrogen Fixation by Sugarcane at Different Stages of Growth

High fertilizer application and over-irrigation in sugarcane systems can cause considerable N2O emissions. Optimized water-fertilization management which reduces N2O emissions, while maintaining sugarcane biomass, is crucial, but may affect nitrogen fixation by sugarcane. This study evaluated the combined effect of water-fertilization on sugarcane biomass and nitrogen fixation in field trials in southern China. Treatments included drip and spray irrigation, with three levels (0% (low), 50% (medium), 100% (high)) of irrigation and of fertilizer. A rain-fed crop (no irrigation or fertilizer) was included as the control. The results showed that (1) spray irrigation with medium water and high fertilization increased biomass. The optimum combination in sugarcane elongation stage was drip irrigation with medium water and high fertilization, while drip irrigation with high water and high fertilization was the best choice for maturity stage. (2) For sugarcane nitrogen (δ15N) content, spray irrigation with medium water and high fertilization was the best combination in seedling and tillering stages. The optimum combination in the elongation stage was drip irrigation with medium water and high fertilization, and in maturity stage was drip irrigation with high water and high fertilization. (3) For soil (δ15N content), drip irrigation with high water and high fertilization proved optimal for seedling, tillering, and maturity stages. (4) In seedling stage, sugarcane (δ15N content) was found to be strongly correlated with leaf area index, soil water, soil temperature, and soil electrical conductivity. Soil (δ15N content) was correlated with photosynthesis and soil temperature. In conclusion, drip irrigation appears most suitable for field planting, while the best treatment in seedling and tillering stages is medium water-high fertilization, and that the best in elongation stage is high water-medium fertilization. The optimum water-fertilizer combinations identified here can provide a scientific basis for optimization and management of irrigation and fertilization in China and other regions with similar environments

Effects of Coupling Water and Fertilizer on Agronomic Traits, Sugar Content and Yield of Sugarcane in Guangxi, China

This work is a contribution to applied water and fertilizer coupling efforts aiming at increasing crop productivity on sugarcane plantations through the analysis of average cane yields obtained following main agronomic traits in growth and sugar content of plantations, in order to improve irrigation scheduling practices. A field experiment was carried out, testing drip irrigation (D), with four levels (0%, 50%, 100% and 150%) of water (W) and four levels (0%, 50%, 100% and 150%) of fertilizer (F) with three replicates. Rain-fed crop (neither irrigation nor fertilizer DW0F0) and manpower irrigation were included as the control (W1F1). The effects of water and fertilizer on agronomic traits (plant high, stem diameter, effective stem number and single stem weight), sugarcane yield and sugar content were studied in Guangxi (southwest China) from 2018–2020. Compared with W1F1, the agronomic traits were higher under DW1F1 treatment; for sugar content, the benefit of the combined treatment was W0.5F0; for sugarcane yield, the best treatment was DW1F1, followed by DW1.5F1. To obtain maximum sugar yield, it is recommended to apply a N fertilizer dose of 292 kg ha−1, K2 O fertilizer 146.55 kg ha−1 and P2 O5 fertilizer 439.5 kg ha−1 with water 1778.4 m3 ha−1 . The results could not only boost efficiency of water and fertilizer, but also establish the reasonable irrigation and fertilizer measure, and regulate yield of sugarcane. It could offer some ideas and techniques for developing precision farming.This research was funded by Guangxi Key R&D Program, grant number Guike AB19245040

A numerical coupling method for particle tracking in electromagnetic fields

With the arrival of the information age, the electromagnetic energy in space increases constantly, resulting in the influence of electromagnetic waves on the charged aerosol particles in the environment which should be taken into account. Here, a numerical coupling method based on temporal and spatial scales is proposed to solve the difficulty in obtaining the trajectory of particles under the action of high-frequency electromagnetic waves. In the temporal scale, two constant forces with linear relationship are used to equilibrate the electromagnetic field forces under different conditions, however the above-mentioned equivalent method has the space limitation; in addition, on the spatial scale, the model with larger geometry should be divided into multiple basic modules spatially, the domain division method is adopted and due to the above method it can be used well in the basic module. Verified the correctness through the comparison of the results, and compared with the traditional method, the above method greatly reduces the computational complexity. Some interesting results were obtained by calculating the modulated waves with the above method, which indicate that special forms of electromagnetic waves will significantly affect the motion of particles

The Atomic Layer Etching Technique with Surface Treatment Function for InAlN/GaN Heterostructure

This paper studied an atomic layer etching (ALE) technique with a surface treatment function for InAlN/GaN heterostructures with AlN spacer layers. Various parameters were attempted, and 30 s O2 + 15 W BCl3 was chosen as the optimal recipe. The optimal ALE approach exhibited satisfactory etching results, with regard to the etch-stop effect, compared with other techniques. The atomic force microscopy (AFM) results showed an etching per cycle (EPC) value of 0.15 nm/cycle, with a 0.996 fit coefficient and root mean square (RMS) surface roughness of around 0.61 nm (0.71 nm for as-grown sample), which was the lowest in comparison with digital etching (0.69 nm), Cl2/BCl3 continuous etching (0.91 nm) and BCl3 continuous etching (0.89 nm). X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy with energy dispersive X-ray spectroscopy measurements (STEM/EDS) verified the indium clustered phenomena at the bottom apex of V-pit defects in the epi structure of InAlN/GaN high electron mobility transistors (HEMTs) for the first time, in addition to the surface morphology optimization for the ALE under-etching technique used in this work. The resistor hall effect (Hall) and AFM measurements demonstrated that after 4 or 5 ALE cycles, the two-dimensional electron gas (2-DEG) density and RMS roughness were improved by 15% and 11.4%, respectively, while the sheet resistance (Rsh) was reduced by 6.7%, suggesting a good surface treatment function. These findings were important for realizing high-performance InAlN/GaN HEMTs