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Aiming at the problem of how to reasonably correct the position of UAV formation, we take the circular formation composed of 10 UAVs and the conical formation composed of 15 UAVs in the same plane as examples to study how to adjust the number and angle of UAV signal transmission so that the UAVs in the entire formation are in the designated position. This paper uses geometric model, greedy strategy and other methods, uses python, matlab and other software to obtain a reasonable and effective mathematical model, and makes a test and evaluation. The research results show that no matter circular, conical or other graphics, we can construct a triangle by connecting the transmitting signal and the receiving signal UAV, and solve the problem to obtain the best transmitting signal angle and the minimum number of sorties required; If there is no triangle between the UAV transmitting the signal and each UAV receiving the signal, the UAV receiving the signal will not reach the designated position. Nowadays, the use of UAVs is more and more extensive. The cooperation of multiple UAVs can complete many functions such as detection and performance, which is also the significance of our research on how UAVs can better receive signals.

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 transmitting and receiving equipment. The system uses GPS as the main clock source. The information within the GPS system will be encoded and decoded using the FPGA. This allows us to obtain both UTC time and the time of the IRIG-B code format, enabling compatibility with the various system interfaces. Our experiments have confirmed that the system has a time error at the microsecond level, and the precision satisfies the design requirements. This verifies the validity and reliability of the system.

IntroductionThe present study evaluated oxidative stress indicators in plasma of beef calves supplemented with a rumen-protected methionine (L0 = receiving ration top-dressed with a ground corn carrier, L1 = receiving ration top-dressed with 10.0 g of rumen-protected methionine supplement in a ground corn carrier, L2 = receiving ration top-dressed with 20.0 g of rumen-protected methionine supplement in a ground corn carrier) and administered lipopolysaccharide (LPS). An additional objective evaluated the effect of LPS on plasma metabolites.MethodsFollowing an initial feeding period (40 d), steers (n = 32; 379 kg ± 30.7) were intravenously administered LPS (0.25 μg/kg BW). Blood was collected via jugular catheter at -2, 0, 2, 4, 6, 8, 10, 12, 18, 24, 36, and 48 h relative to LPS administration (0 h). Plasma was analyzed for amino acid (AA) concentrations, ferric-reducing antioxidant power (FRAP), thiobarbituric reactive substances (TBARS), and reactive oxygen species (ROS). Metabolomic analysis occurred for control cattle at -2, 2, and 8 h.Results and discussionPlasma AA asparginine and methionine were increased with supplementation (P < 0.01). The greatest FRAP values were observed at -2, 0, 2, 36, and 48 h (P < 0.001). At 6 and 8 h, FRAP decreased to their lowest values (P < 0.001). Amount of TBARS increased at 2 h but declined at 4h (P < 0.001). A treatment × time interaction occurred for ROS (P < 0.001). At 2 h, ROS was greatest in L0 cattle, least in L2, and intermediate in L1 but declined at 4 h in all treatments (P < 0.001). Values peaked at 6 h for L1 and L2 cattle, followed by a decline at 8 h (P < 0.001). Values for L0 cattle were similar from 4 to 6 h (P = 0.371) but increased at 8 h (P < 0.001). Finally, L0 plasma metabolites present at -2 h segregated from those present at 2 and 8 h (P < 0.05). Differences were primarily driven by taurocholic acid, LysoPE, butyric acid, acitretin, and tauromuricholic acid. These data demonstrate that LPS may alter oxidative stress indicators and plasma metabolites. However, methionine supplementation may mitigate oxidative stress.

Status epilepticus (SE), a medical emergency that is typically terminated through antiepileptic drug treatment, leads to hippocampus dysfunction typified by neurodegeneration, inflammation, altered neurogenesis, as well as cognitive and memory deficits. Here, we examined the effects of intranasal (IN) administration of extracellular vesicles (EVs) secreted from human bone marrow-derived mesenchymal stem cells (MSCs) on SE-induced adverse changes. The EVs used in this study are referred to as A1-exosomes because of their robust antiinflammatory properties. We subjected young mice to pilocarpine-induced SE for 2 h and then administered A1-exosomes or vehicle IN twice over 24 h. The A1-exosomes reached the hippocampus within 6 h of administration, and animals receiving them exhibited diminished loss of glutamatergic and GABAergic neurons and greatly reduced inflammation in the hippocampus. Moreover, the neuroprotective and antiinflammatory effects of A1-exosomes were coupled with long-term preservation of normal hippocampal neurogenesis and cognitive and memory function, in contrast to waned and abnormal neurogenesis, persistent inflammation, and functional deficits in animals receiving vehicle. These results provide evidence that IN administration of A1-exosomes is efficient for minimizing the adverse effects of SE in the hippocampus and preventing SE-induced cognitive and memory impairments.

From a list of the top prescribed drugs in Canada, 11 pharmaceuticals and two metabolites were selected for study in municipal sewage treatment plant effluents and receiving waters. Wastewater samples were collected from 16 wastewater treatment plants across Southwest Nova Scotia including the Annapolis Valley, South Shore, and Metropolitan Halifax. Samples were also collected between 100 and 200 m downstream of effluent outflows. Seven pharmaceuticals were found above μg/L levels with their highest concentrations as follows: metformin (10.6 μg/L), acetaminophen (28.9 μg/L), paraxanthine (18.2 μg/L), cotinine (3.10 μg/L), caffeine (115 μg/L), naproxen (29.1 μg/L), and venlafaxine (2.65 μg/L). Metformin, paraxanthine, caffeine, naproxen, ramipril, and venlafaxine were detected in every wastewater effluent sample. Statistical analysis revealed significant differences in pharmaceutical occurrence by treatment methods, weak dependence of pharmaceutical concentrations on populations, and the co-occurrence of some pharmaceuticals. Experimental results might indicate the limitation of primary only treatment methods in breaking down pharmaceuticals.

Large-scale and rapid improvement in wastewater treatment is common practice in developing countries, yet this influence on nutrient regimes in receiving waterbodies is rarely examined at broad spatial and temporal scales. Here, we present a study linking decadal nutrient monitoring data in lakes with the corresponding estimates of five major anthropogenic nutrient discharges in their surrounding watersheds over time. Within a continuous monitoring dataset covering the period 2008 to 2017, we find that due to different rates of change in TN and TP concentrations, 24 of 46 lakes, mostly located in China’s populated regions, showed increasing TN/TP mass ratios; only 3 lakes showed a decrease. Quantitative relationships between in-lake nutrient concentrations (and their ratios) and anthropogenic nutrient discharges in the surrounding watersheds indicate that increase of lake TN/TP ratios is associated with the rapid improvement in municipal wastewater treatment. Due to the higher removal efficiency of TP compared with TN, TN/TP mass ratios in total municipal wastewater discharge have continued to increase from a median of 10.7 (95% confidence interval, 7.6 to 15.1) in 2008 to 17.7 (95% confidence interval, 13.2 to 27.2) in 2017. Improving municipal wastewater collection and treatment worldwide is an important target within the 17 sustainable development goals set by the United Nations. Given potential ecological impacts on biodiversity and ecosystem function of altered nutrient ratios in wastewater discharge, our results suggest that long-term strategies for domestic wastewater management should not merely focus on total reductions of nutrient discharges but also consider their stoichiometric balance.

The tailwater from wastewater treatment plants serves as an important water resource in arid regions, alleviating the conflict between supply and demand. However, the effects of different tailwater discharge proportions on microbial community dynamics remain unclear. In this study, we investigated the effects of different tailwater discharge proportions on the water quality and microbial community characteristics of sediments in receiving water bodies under controlled conditions (WF-1, WF-2, WF-3, WF-4, and WF-5, containing 0% tailwater + 100% natural water, 25% tailwater + 75% natural water, 50% tailwater + 50% natural water, 75% tailwater + 25% natural water, and 100% tailwater + 0% natural water, respectively). Microbial co-occurrence networks and structural equation model were used to unveil the relationship between microbial communities and their shaping factors. Results showed that distinct microbial community compositions were found in the sediments with low- (< 50%) and high- (> 50%) proportions of tailwater. Specifically, WCHB1-41 and g_4-29–1 , which are involved in organic degradation-related functions, were the key genera in the high-proportion cluster. A total of 21 taxa were more abundant in the low-proportion (< 50%) cluster than that in high-proportion (> 50%). Moreover, higher modularity was observed in the low-proportion. Total phosphorus directly affected while ammonia nitrogen indirectly affected the microbial community structure. Our findings support the distinct heterogeneity of microbial communities driven by tailwater discharge in receiving water bodies, and further confirmed that high-proportion tailwater depletes sensitive microbial communities, which may be avoided through scientific management.

Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management. Significance Freshwater resources are unevenly distributed in China. This situation drives a significant amount of water flow both physically and virtually across China. Here, we report on our quantification of China’s physical and virtual water flows and associated water stress at the provincial level. In 2007, interprovincial physical water flows amounted to only a small part of China’s total water supply, but virtual water flows amounted to over one-third of supply. We found that both physical and virtual water flows exacerbated water stress for the main water-exporting provinces. The results highlight the need for more emphasis to be placed on water demand management rather than the current focus on supply-oriented management.

Sharing information coherently between nodes of a quantum network is fundamental to distributed quantum information processing. In this scheme, the computation is divided into subroutines and performed on several smaller quantum registers that are connected by classical and quantum channels 1 . A direct quantum channel, which connects nodes deterministically rather than probabilistically, achieves larger entanglement rates between nodes and is advantageous for distributed fault-tolerant quantum computation 2 . Here we implement deterministic state-transfer and entanglement protocols between two superconducting qubits fabricated on separate chips. Superconducting circuits 3 constitute a universal quantum node 4 that is capable of sending, receiving, storing and processing quantum information 5 – 8 . Our implementation is based on an all-microwave cavity-assisted Raman process 9 , which entangles or transfers the qubit state of a transmon-type artificial atom 10 with a time-symmetric itinerant single photon. We transfer qubit states by absorbing these itinerant photons at the receiving node, with a probability of 98.1 ± 0.1 per cent, achieving a transfer-process fidelity of 80.02 ± 0.07 per cent for a protocol duration of only 180 nanoseconds. We also prepare remote entanglement on demand with a fidelity as high as 78.9 ± 0.1 per cent at a rate of 50 kilohertz. Our results are in excellent agreement with numerical simulations based on a master-equation description of the system. This deterministic protocol has the potential to be used for quantum computing distributed across different nodes of a cryogenic network. Deterministic quantum state transfer and entanglement generation is demonstrated between superconducting qubits on distant chips using single photons.