Energy-Efficiency Maximization for a WPT-D2D Pair in a MISO-NOMA Downlink Network

The combination of non-orthogonal multiple access (NOMA) and wireless power transfer (WPT) is a promising solution to enhance the energy efficiency of Device-to-Device (D2D) enabled wireless communication networks. In this paper, we focus on maximizing the energy efficiency of a WPT-D2D pair in a multiple-input single-output (MISO)-NOMA downlink network, by alternatively optimizing the beamforming vectors of the base station (BS) and the time switching coefficient of the WPT assisted D2D transmitter. The formulated energy efficiency maximization problem is non-convex due to the highly coupled variables. To efficiently address the non-convex problem, we first divide it into two subproblems. Afterwards, an alternating algorithm based on the Dinkelbach method and quadratic transform is proposed to solve the two subproblems iteratively. To verify the proposed alternating algorithm's accuracy, partial exhaustive search algorithm is proposed as a benchmark. We also utilize a deep reinforcement learning (DRL) method to solve the non-convex problem and compare it with the proposed algorithm. To demonstrate the respective superiority of the proposed algorithm and DRL-based method, simulations are performed for two scenarios of perfect and imperfect channel state information (CSI). Simulation results are provided to compare NOMA and orthogonal multiple access (OMA), which demonstrate the superior performance of energy efficiency of the NOMA scheme

Deep Reinforcement Learning Based Optimization for IRS Based UAV-NOMA Downlink Networks

This paper investigates the application of deep deterministic policy gradient (DDPG) to intelligent reflecting surface (IRS) based unmanned aerial vehicles (UAV) assisted non-orthogonal multiple access (NOMA) downlink networks. The deployment of the UAV equipped with an IRS is important, as the UAV increases the flexibility of the IRS significantly, especially for the case of users who have no line of sight (LoS) path to the base station (BS). Therefore, the aim of this letter is to maximize the sum rate by jointly optimizing the power allocation of the BS, the phase shifting of the IRS and the horizontal position of the UAV. Because the formulated problem is not convex, the DDPG algorithm is utilized to solve it. The computer simulation results are provided to show the superior performance of the proposed DDPG based algorithm

Exploring the effects of subsoiling tillage under various irrigation regimes on the evapotranspiration and crop water productivity of winter wheat using RZWQM2

Food security is an important pre-requisite for human well-being; however, water shortages and poor quality of arable land threaten food security in the North China Plain (NCP). Subsoiling and proper irrigation can improve soil structure and increase crop yield. This study investigated the effects of two tillage methods (rotary tillage at 15 cm depth, R15; subsoiling at 35 cm depth, S35) combined with three irrigation treatments (no irrigation during the winter wheat growing season, I0; 60 mm irrigation at the jointing stage, I1; 60 mm irrigation at both the jointing and heading stages, I2) on soil moisture dynamics, evapotranspiration, and winter wheat yield. The Root Zone Water Quality Model (RZWQM2) was adopted after calibration and validation base on a field experiment. The results showed that the normalized root mean square errors (calibration and test) between the actual and simulated values of soil water storage (SWS), evapotranspiration (ET), and yield were 7.45–10.87%, 3.80–7.21%, and 5.38–14.15%, respectively. Subsoiling improved winter wheat soil moisture conditions, yield, and crop water productivity (CWP), and irrigation during the winter wheat growing seasons increased crop yield (I2 > I1 > I0) and CWP (I1 > I2 > I0). The best yield treatment during the 2020–2022 winter wheat growing seasons was S35-I2. However, the CWP of S35-I1 was 2.67% higher than that of S35-I2. Tillage methods change the ET structure of winter wheat fields. Compared to rotary tillage, subsoiling reduced actual ET by 16.11% and increased actual transpiration by 10.44%. The results of this study indicate that subsoiling at a depth of 35 cm and 60 mm irrigation at the jointing stage could improve the CWP of winter wheat in the NCP

Effects of Foliar Spraying of Organic Selenium and Nano-Selenium Fertilizer on Pak Choi (<i>Brassica chinensis</i> var. <i>pekinensis</i>. cv. ‘Suzhouqing’) under Low Temperature Stress

The effects of foliar spraying of organic selenium and nano-selenium fertilizer on pak choi (Brassica chinensis var. pekinensis. cv. ‘Suzhouqing’) under low temperature were investigated. The impacts on plant growth, antioxidant capacities, and nutritional profiles were studied. Exogenous selenium was applied at three rates: 5, 10, 20 mg L−1, and RNA-Seq technology was used to sequence the transcriptome of leaves. The study revealed that selenium influenced leaf weight and total selenium content through three main mechanisms. First, it protected photosynthetic pigments and boosted photosynthetic capacity by up-regulating LHca2, LHcb1, LHca1, and LHcb4. Second, it enhanced antioxidant capacity by elevating the expression of genes such as superoxide dismutase and monodehydroascorbic acid. Third, it facilitated selenium absorption through endocytosis, transported selenium using the ABC transport gene family, and regulated selenium metabolism-related genes like cysteine synthetase and glutaredoxin. Nine hub genes identified with a weighted gene co-expression network analysis were closely associated with these mechanisms. The results of a functional enrichment analysis were consistent with those of a Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis conducted on DEGs, thus confirming the reliability of these findings. Therefore, this study can provide scientific basis for pak choi production with selenium fortification by selenium application

Experimental and Numerical Investigation on the Aerosol Micro-Jet 3D Printing of Flexible Electronic Devices

In this study, the optimal forming parameters for printing flexible circuits using aerosol jet printing technology are explored through numerical simulation and experiments. The printhead during the deposition process is numerically simulated. By employing the controlled variable method, the process parameters such as gas flow rate, working distance, nozzle diameter, and printing speed are selected to investigate their effects on the morphology of the printed lines. Accordingly, single-factor experiments are designed to validate the printing of flexible circuits on both planar and curved substrates. Laser micro-sintering is utilized to improve the conductivity of the printed lines and ultimately fabricate flexible strain sensors. Under the sheath gas flow rate of 400 sccm, carrier gas flow rate of 100 sccm, working distance of 3 mm, nozzle diameter of 500 μm, and printing speed of 10 mm/s, the optimal morphology of the printed lines is achieved with low linewidth characteristics. The variations in the focal ratio, working distance, nozzle diameter, and printing speed significantly affect the minimum feature line width and morphology of the printed lines

Structure–Biodegradability Relationship of Nonylphenol Isomers in Two Soils with Long-Term Reclaimed Water Irrigation

Nonylphenol (NP), as one of the typical endocrine disrupter chemicals (EDCs), has a high detection concentration and frequency in reclaimed water. This research focused on the degradation of NP isomers in two typical reclaimed water irrigation fields in Daxing, China, and Florida, USA. The results showed that the half-lives of NP isomer degradation in the soil of China and Florida were 2.03–8.66 d and 5.16–11.83 d, respectively. The degradation of NP isomers was structure-specific. Isomers of NP5, NP2, NP11, and NP3 had the highest degradation rates in the two soils; NP12, NP7, and NP6 were the isomers with medium degradation rates; and NP4, NP1, NP10, NP9, and NP8 had the slowest degradation rates. Steric hindrance and mean information index for the magnitude of distance (IDWbar) were found to be the better indexes for measuring the degradation of NP isomers compared with the length of the side chain, the type of the substitute, and the molecular connectivity. This study offers insights into the characteristics of NP isomers and two reliable indicators for measuring the degradation of NP isomers, which could provide data support for the environmental fate and the health risk assessment of NP in the future

Mmu-miR-27a-5p-Dependent Upregulation of MCPIP1 Inhibits the Inflammatory Response in LPS-Induced RAW264.7 Macrophage Cells

Lipopolysaccharide (LPS) stimulates macrophages to release proinflammatory cytokines. MicroRNAs (miRNAs) are short noncoding RNAs that are involved in inflammatory reaction. Our previously study identified the downregulated expression of mmu-miR-27a-5p in RAW267.4 cells treated with LPS. To dissect the mechanism that mmu-miR-27a-5p regulates target genes and affects proinflammatory cytokine secretion more clearly, based on previous bioinformatics prediction data, one of the potential target genes, MCPIP1 was observed to be upregulated with qRT-PCR and western blot. Luciferase reporter assays were performed to further confirm in silico prediction and determine that MCPIP1 is the target of mmu-miR-27-5p. The results suggested that mmu-miR-27a-5p directly targeted the 3′-UTR of MCPIP1 and the interaction between mmu-miR-27-5p and the 3′-UTR of MCPIP1 is sequence-specific. MCPIP1 overexpression decreased the secretion of IL-6, IL-1β, and IL-10 in macrophage cells stimulated with LPS. Our findings may provide the important information for the precise roles of mmu-miR-27a-5p in the macrophage inflammatory response to LPS stimulation in the future