Application-Level Packet Loss Rate Measurement Based on Improved L-Rex Model

The current network information asymmetry is infringing the interests of end users in non-neutral network environment. To empower users, application-level performance measurements are usually used to rebalance the information asymmetry currently disfavoring users. Application-level packet loss rate, as an important key performance indicator (KPI), receives extensive attention in academia. However, every coin has its two sides. Although the application-level packet loss estimation is simple and nonintrusive, since the information available from the application layer is relatively scarce compared to the lower layers, the estimation accuracy has no guarantee. In view of this, taking the L-Rex model as the cut-in spot, this paper focuses on leveraging the self-clocking mechanism of Transmission Control Protocol (TCP) to improve the accuracy of application-level loss estimation. Meanwhile, owing to the dynamically estimated parameters and the weakened packet reordering impact, the robustness of estimation is also expected to be improved accordingly. Finally, a series of comparative experiments at the practically relevant parameter space show that the enhanced approach and strategy detailed in this paper are effective

Investigating bubble dynamics on silicon carbide surfaces during flow boiling

Silicon carbide (SiC) is a promising candidate for Accident-Tolerant Fuels (ATFs) in nuclear power plants, critical for maintaining functionality and extending service lifespan due to its superior heat transfer properties. However, the dynamics of bubble formation, size, and distribution on SiC surfaces during flow boiling, especially under the influence of porosity, remain poorly understood. This study aims to elucidate the impact of heat transfer characteristics and bubble distribution properties under flow boiling condition on SiC surface. An experimental was conducted with superheat ranging from 0 to 30K, subcooling ranging from 0 to 12K, and a maximum Reynolds number of 10,400. Videos were recorded and U-net was employed to identify bubble diameters, perimeters, orientations, and positions. Results indicate that the superheat significantly affects bubble size parameters, such as departure diameter and perimeter, but does not influence the distribution categories. Regarding bubble distribution, the aspect ratio and size of bubbles follow a log-normal distribution, while their orientation follows a normal distribution. Under the same experimental conditions, surfaces with higher porosities exhibit increased heat flux, and the Sauter mean diameter of bubbles is larger

Evaluating Effects of Regulated Deficit Irrigation under Mulched on Yield and Quality of Pumpkin in a Cold and Arid Climate

As the most effective irrigation method in arid and semi-arid regions, drip irrigation under mulch could general comprehension of the production efficiency of agricultural irrigation water, and reduce agriculture consumption of water resources. The paper has carried out an investigation over a two year period (2020–2021) in a semi-arid climate in the Hexi Oasis region of China, aiming at determining the influence of regulated deficit irrigation (RDI) under mulch on the growth, yield, water use efficiency (WUE), irrigation water use efficiency (IWUE) and quality of pumpkin at different growth stages. A total of nine treatments with three irrigation levels (75–85% field capacity, 65–75% field capacity, and 55–65% field capacity) have been used in four growing periods of pumpkin (seedling, vine extension, fruit expansion, and maturation stages). The results have shown that light water deficit treatment at the seedling stage had the highest water use efficiency (12.47 kg/m3) without significantly affecting yield (45,966.90 kg/ha), and improved pumpkin fruit quality. It was concluded that light water deficit at the seedling stage and adequate irrigation at other development stages was the optimal irrigation strategy for pumpkin growth. The results of this research provide theoretical and technical support for efficient water-saving plantation and industrialization of pumpkin in the Hexi Oasis

Modelling and Evaluation of Potato Water Production Functions in a Cold and Arid Environment

This study was conducted at the Yimin Irrigation Experiment Station, Minle County, Zhangye City, Gansu Province, from April to October in 2019 and 2020. The relationship between water consumption and yield of potato at different stages of fertility under deficit-regulated irrigation was analyzed in a field trial study over two growing seasons. The results showed that the average annual water consumption in the tuber bulking stage was the largest, reaching 185.35~239.52 mm, followed by the average annual water consumption in the tuber initiation stage and starch accumulation stage, which were 100.02~132.30 mm and 82.48~112.36 mm, respectively, and the average annual water consumption in the seedling stage was the least, at 49.32~69.81 mm. Simultaneously, the average annual yield of potatoes in the treatment of WD1 was the highest, reaching 47,766.96 kg·hm−2, followed by CK, which was 43,707.6 kg·hm−2, and the yield of WD6 was the smallest in the treatment of moderate water deficit during tuber initiation, which was only 35,721.25 kg·hm−2. Combining the four moisture production function models of Jensen, Minhas, Blank and Stewart, the Jensen and Stewart models were identified as suitable for the potato moisture production function in a cold and arid environment. The water production function model was used to investigate the relationship between water consumption and yield in each growth period of potato, and to provide a theoretical basis for the optimization of the irrigation system under deficit-regulating irrigation conditions for potato in this irrigation area

Comprehensive Regulation of Water–Nitrogen Coupling in Hybrid Seed Maize in the Hexi Oasis Irrigation Area Based on the Synergy of Multiple Indicators

Water scarcity and the excessive application of nitrogen fertilizer are key factors limiting the sustainable development of the hybrid seed maize industry in the oasis agricultural areas of the Hexi Corridor in China. To determine the optimal water–nitrogen management regime of hybrid seed maize, we established a field experiment in 2020–2021 with three irrigation quotas (W1, W2, and W3 were 60, 80, and 100% of the local conventional irrigation quota, respectively) and four nitrogen application levels (N0, N1, N2, and N3 were 0, 190, 285, 380 kg·hm−2). We analysed the influence of different water–nitrogen combinations on indices of seed vigour, yield, water use efficiency (WUE), irrigation water use efficiency (IUE), the partial productivity of nitrogen fertilizer (NFP), and the nitrogen fertilizer agronomic use efficiency (NFA) of hybrid seed maize. A comprehensive growth evaluation system for hybrid seed maize was established based on the AHP, entropy weight, and TOPSIS methods, and a coupled water–nitrogen response model for hybrid seed maize was established with the objectives of obtaining high-yield, efficient, and high-seed vigour. The results showed that the yield of hybrid seed maize, NFP, and NFA gradually increased with the increase in the irrigation amount, while IUE continuously decreased; the yield of hybrid seed maize, WUE, and NFA increased and then decreased, while NFP continuously decreased with an increase in the amount of nitrogen application. Further, treatment N2W3 had higher water and nitrogen use efficiency and the highest yield and seed viability with a yield of 9209.11 kg·hm−2 and germination percentage, germination index, and vigour index of 97.22, 58.91, and 1.55%, respectively. The model of the integrated growth response of hybrid seed maize to water–nitrogen showed that the combined benefits of the hybrid seed maize yield, WUE, and seed viability could be maximised in conjunction with the irrigation rate ranging from 3558.90 to 3971.64 m3·hm−2 and the fertiliser application rate of 262.20 to 320.53 kg·hm−2. This study can provide scientific guidance and act as a decision-making reference for the productive, efficient, and sustainable development of hybrid seed maize in the oasis agricultural area of the Hexi Corridor

Risk factors associated with the prevalence of neck and shoulder pain among high school students: a cross-sectional survey in China

Abstract Background After the COVID-19 outbreak, many Chinese high school students have increased their dependence on electronic devices for studying and life, which may affect the incidence of neck and shoulder pain (NSP) in Chinese adolescents. Methods To evaluate the prevalence of NSP in high school students and its associated risk factors during COVID-19, a survey was conducted among 5,046 high school students in Shanghai, Qinghai, Henan and Macao during the second semester and summer vacation of the 2019–2020 academic year. The questionnaire included questions regarding demographic characteristics, the prevalence of NSP and lifestyle factors such as sedentary behavior, poor posture and electronic device usage. Univariable and multivariable logistic regression was used to analyze the possible influencing factors for neck and shoulder pain. Results A total of 4793 valid questionnaires (95.0%) were collected. The results indicated that the prevalence of NSP was 23.7% among high school students. Binary logistic regression analysis revealed that female gender (P < 0.05, OR = 1.82), grade (P < 0.05, range OR 1.40–1.51) and subject selection (P < 0.05, range OR 0.49–0.68) were risk factors for NSP in high school students. Sedentary behavior (P < 0.05, range OR 1.74–2.36), poor posture (P < 0.05, range OR 1.19–2.56), backpack weight (P < 0.05, range OR 1.17–1.88), exercise style and frequency (P < 0.05, range OR 1.18–1.31; P < 0.05, range OR 0.76–0.79, respectively), and the time spent using electronic devices (P < 0.05, range OR 1.23–1.38)had a significant correlation with NSP in high school students. Conclusions NSP is currently very common among high school students during the outbreak of COVID-19. Sedentary behavior, poor posture and other factors have a great impact on the occurrence of NSP in high school students. Education regarding healthy lifestyle choices should be advocated for to decrease NSP among high school students, such as more physical activity, changing poor postures and reducing the amount of time spent using electronic devices

Maximizing electrical power through the synergistic utilization of solar and space energy sources

Summary: The sun and outer space are two crucial renewable thermodynamic resources that work together to maintain the delicate energy balance of our planet. The challenge lies in harvesting both resources synergistically and converting them into high-quality electricity. Here, we introduce a photovoltaic thermoelectric radiative cooling (PV-TE-RC) system. This system uses the full spectrum of the sun and the atmospheric window to generate electricity and achieve high-quality collaborative utilization of solar energy and space energy. Outdoor experiments have demonstrated the system’s capacity to operate efficiently around the clock. Notably, during the peak solar concentration, the thermoelectric generator (TEG) and the system achieved power outputs of 870 mW/m2 and 85.87 W/m2, respectively. We have further developed a three-dimensional transient coupled simulation model, which can accurately predict its operational limits. Therefore, this study provides practical insights and recommendations for large-scale and efficient collaborative power generation using these two thermodynamic resources

Room Temperature Crystallized Phase‐Pure α‐FAPbI3 Perovskite with In‐Situ Grain‐Boundary Passivation

Abstract Energy loss in perovskite grain boundaries (GBs) is a primary limitation toward high‐efficiency perovskite solar cells (PSCs). Two critical strategies to address this issue are high‐quality crystallization and passivation of GBs. However, the established methods are generally carried out discretely due to the complicated mechanisms of grain growth and defect formation. In this study, a combined method is proposed by introducing 3,4,5‐Trifluoroaniline iodide (TFAI) into the perovskite precursor. The TFAI triggers the union of nano‐sized colloids into microclusters and facilitates the complete phase transition of α‐FAPbI3 at room temperature. The controlled chemical reactivity and strong steric hindrance effect enable the fixed location of TFAI and suppress defects at GBs. This combination of well‐crystallized perovskite grains and effectively passivated GBs leads to an improvement in the open circuit voltage (Voc) of PSCs from 1.08 V to 1.17 V, which is one of the highest recorded Voc without interface modification. The TFAI‐incorporated device achieved a champion PCE of 24.81%. The device maintained a steady power output near its maximum power output point, showing almost no decay over 280 h testing without pre‐processing