Magnetic skyrmion generation by reflective spin-wave focusing

We propose a method to generate magnetic skyrmions by focusing spin waves totally reflected by a curved film edge. Based on the principle of identical magnonic path length, we derive the edge contour that is parabolic and frequency-independent. Micromagnetic simulations are performed to verify our theoretical design. It is found that under proper conditions, magnetic droplet first emerges near the focal point where the spin-wave intensity has been significantly enhanced, and then converts to magnetic skyrmion accompanied by a change of the topological charge. The phase diagram about the amplitude and frequency of the driving field for skyrmion generation is obtained. Our finding would be helpful for the designment of spintronic devices combing the advantage of skyrmionics and magnonics.Comment: 5 pages, 5 figure

Agarose-resolvable InDel markers based on whole genome re-sequencing in cucumber

Insertion and Deletion (InDel) are common features in genomes and are associated with genetic variation. The whole-genome re-sequencing data from two parents (X1 and X2) of the elite cucumber (Cucumis sativus) hybrid variety Lvmei No.1 was used for genome-wide InDel polymorphisms analysis. Obtained sequence reads were mapped to the genome reference sequence of Chinese fresh market type inbred line ‘9930’ and gaps conforming to InDel were pinpointed. Further, the level of cross-parents polymorphism among five pairs of cucumber breeding parents and their corresponding hybrid varieties were used for evaluating hybrid seeds purity test efficiency of InDel markers. A panel of 48 cucumber breeding lines was utilized for PCR amplification versatility and phylogenetic analysis of these markers. In total, 10,470 candidate InDel markers were identified for X1 and X2. Among these, 385 markers with more than 30 nucleotide difference were arbitrary chosen. These markers were selected for experimental resolvability through electrophoresis on an Agarose gel. Two hundred and eleven (211) accounting for 54.81% of markers could be validated as single and clear polymorphic pattern while 174 (45.19%) showed unclear or monomorphic genetic bands between X1 and X2. Cross-parents polymorphism evaluation recorded 68 (32.23%) of these markers, which were designated as cross-parents transferable (CPT) InDel markers. Interestingly, the marker InDel114 presented experimental transferability between cucumber and melon. A panel of 48 cucumber breeding lines including parents of Lvmei No. 1 subjected to PCR amplification versatility using CPT InDel markers successfully clustered them into fruit and common cucumber varieties based on phylogenetic analysis. It is worth noting that 16 of these markers were predominately associated to enzymatic activities in cucumber. These agarose-based InDel markers could constitute a valuable resource for hybrid seeds purity testing, germplasm classification and marker-assisted breeding in cucumber

Spatial-temporal evolution of water resources utilization efficiency in Jiangsu Province

Improving water resource utilization efficiency is essential in alleviating the crisis of water resource shortage and promoting the sustainable development of the social economy. Based on the data envelopment analysis (DEA) and Malmquist index, the agricultural, industrial, and domestic water resource utilization efficiency of Jiangsu Province from 2011 to 2020 are evaluated, respectively. The results show that the DEA efficiency of agriculture and industrial water use is greater than that of domestic while the improvement of agricultural and domestic water efficiency is larger than that of industrial. Temporally, the water use efficiency was on an increasing trend from 2011 to 2020, and technological progress is the main factor in improving the water resource utilization efficiency. Spatially, the water use efficiency of southern cities in Jiangsu Province is higher than that of northern and central cities, but the difference between cities is gradually narrowing. To improve the efficiency of water resource efficiency, the government should formulate water resource management policies according to local conditions. HIGHLIGHTS Analyze water resource utilization efficiency from dynamic and static perspectives.; Comparative the water use efficiency from different sectors.; Provide new ideas for urban water resource utilization.

Synergetic development assessment of transboundary watershed ecological compensation

Ecological compensation (EC) is essential to promote the coordinated and sustainable development of the watershed. Firstly, the synergetic development index system of the watershed EC was proposed, which includes the economic benefits, water conservation, pollution treatment, and environmental supervision. Then, the order degree of subsystems was calculated. Finally, the synergetic development level of the watershed EC was evaluated. Taking the upstream (Ma'anshan) and the downstream (Nanjing) of the Chu River as the case study area, the results showed that: (1) From 2011 to 2020, the synergetic development level between Ma'anshan and Nanjing has showed an upward trend; (2) The synergetic development level of the watershed EC in the Chu River has reached basic synergy in 2020; (3) Ma'anshan concentrates on protecting the water ecological environment while Nanjing concentrates on economic growth and water pollution control will improve the synergy degree. This study can provide references for the optimization of watershed EC mechanism, and to promote watershed coordinated development. HIGHLIGHTS The watershed ecological compensation (EC) synergetic development index system is proposed.; The synergy degree between upstream and downstream is analyzed.; The upstream focuses on ecological environment protection while the downstream focuses on water pollution control will improve the efficiency of EC.

Research on the Carbon Emission Reduction Potential of the Ports in the Yangtze River Delta of China

Green port construction has a profound impact on China’s international climate commitment to carbon neutrality by 2050. To examine the carbon emission reduction potential of 20 major ports in the Yangtze River Delta port cluster of China, this study takes the perspective of environmental efficiency and employs dynamic exogenous variable DEA in efficiency evaluation. The results show the increasing environmental efficiency of the ports in the Yangtze River Delta, rising from 0.5116 in 2013 to 0.7276 in 2019. Also, there are significant spatial differences in efficiency. After considering exogenous variable, the average efficiency has increased from 0.5537 to 0.6276, indicating that regional green development is a critical factor in port environmental efficiency evaluation. Finally, the overall efficiency of input and output have risen, the slackness of carbon emission shows a trend of decreasing, and there is great potential for reducing carbon emissions from the perspective of port environmental efficiency. The previous studies paid less attention to dynamic efficiency, exogenous variables, and carbon emission. Therefore, this paper is the first comprehensive examination on the carbon emission reduction potential of China’s Yangtze River Delta port cluster from the perspective of dynamic environmental efficiency

Agricultural Drought Risk Evaluation Based on an Optimized Comprehensive Index System

In this study, a new optimized comprehensive drought index system (OCDIS) was developed based on pressure-state-response (PSR) and random forest (RF). Then the pressure, state, response, and integrated agricultural drought risk were evaluated according to the synthetic-weight variable fuzzy set (SW-VFS) model. Finally, the countermeasures in terms of pressure, state, and response were discussed. The proposed index has been implemented in Qujing, Yunnan Province, China. The results showed that of the 10 indices included in the OCDIS, the four most important indices for agricultural drought risk management are reservoir storage capacity, precipitation anomaly percentage, soil moisture, and per capita annual income. The pressure risk and response risk of Malong are relatively higher than other counties. The integrated results indicated that most counties of Quijng have moderate drought risk. The assessment results are consistent with the actual situation of Qujing. The proposed model provides a scientific and objective way to develop the risk index system of agricultural drought. This study can potentially assist government agencies with information on the most important drought impacts and provide the basis for science-informed decision-making

On the Coupling and Coordination Development between Environment and Economy: A Case Study in the Yangtze River Delta of China

The coupling and coordination development of the environment and economy (CC2E) is one of the most vital issues to sustainable development. This paper adopted the coupling coordination model, projection pursuit algorithm, and random forest model to explore the spatial-temporal evolution and influencing factors of the CC2E in the Yangtze River Delta from 2015 to 2019, respectively. The results showed that: (1) The degree of coupling coordination (DCC) of the CC2E in most cities of the Yangtze River Delta has risen from primary coordination to intermediate coordination. (2) In the spatial perspective, the distribution of DCC is correlated with geographical location. The value of DCC in the western region was significantly lower than that of the eastern cities. (3) The influencing factors results showed that the GDP in the economic subsystem and the annual average concentration of PM2.5 in the environmental subsystem were the most influencing factors of DCC in the Yangtze River Delta. The established index system of CC2E and the measurements of CC2E provide a new idea for how to achieve sustainable development. Meanwhile, this study can provide recommendations for formulating the environmental protection and economic development policy

Research on Intelligent Grading Evaluation of Water Conservancy Project Safety Risks Based on Deep Learning

With the rise of artificial intelligence and big data technologies, it is increasingly significant to apply these emerging technologies to scientific decision-making in water conservancy project construction management in the face of many problems in the process of water conservancy project construction. Different from using traditional assessment methods for risk classification of water conservancy construction hazards, this paper integrates a priori attention and constructs a transformer risk prediction model based on a sliding window, which deeply explores the data value of water conservancy construction hazards information, further predicts the risk level of water conservancy construction hazards and realizes efficient and intelligent management of water conservancy project construction hazard identification management

Study on Vulnerability and Coordination of Water-Energy-Food System in Northwest China

Water, energy and food are the basic resources for human survival and development. The coordination development of water-energy-food (W-E-F) is of great significance to promote regional sustainable development. In this study, Northwest China (Shaanxi, Gansu, Qinghai, Ningxia, Xinjiang) was selected as the research case, and an evaluation index system was constructed to assess the vulnerability and coordination of water-energy-food (W-E-F) system based on PSR model. Then, a coupled model based on cloud-matter element model and coordination degree model was proposed. The cloud-matter element model was adopted to evaluate the vulnerability level of W-E-F system. The coordination degree model was employed to calculate the coordination degrees of W-E-F system. The results showed that, from 2006 to 2015, the vulnerability levels of W-E-F system in Northwest China were mostly at Level 1. The coordination degrees of W-E-F system belonged to the transitional development level (II) in most years. The vulnerability and coordination problems of W-E-F system in Northwest China were severe. The comprehensive vulnerability index values of W-E-F system were generally on the rise, but far from reaching a good level. Moreover, the comprehensive vulnerability index values and coordination degrees of W-E-F system in Northwest China do not match well. Finally, the countermeasures and suggestions to improve the coordinated development of water resource, energy and food in Northwest China were put forward

Risk Assessment of Urban Rainstorm Disaster Based on Multi-Layer Weighted Principal Component Analysis: A Case Study of Nanjing, China

Nanjing city is taken as a case in this urban rainstorm disaster risk research. Using the data of meteorology and social-economy statistics of Nanjing area, the paper selected ten indicators to establish the risk assessment system of urban rainstorm disaster from the aspects of the vulnerability of hazard-affected body, the fragility of disaster-pregnant environment, and the danger of hazard factors. Multi-layer weighted principal component analysis (MLWPCA) is an extension of the principal component analysis (PCA). The MLWPCA is based on factor analysis for the division subsystem. Then the PCA is used to analyze the indicators in each subsystem and weighted to synthesize. ArcGIS is used to describe regional differences in the urban rainstorm disaster risk. Results show that the MLWPCA is more targeted and discriminatory than principal component analysis in the risk assessment of urban rainstorm disaster. Hazard-affected body and disaster-pregnant environment have greater impacts on the risk assessment of rainstorm disaster in Nanjing, but the influence of hazard factors is few. Spatially, there is a large gap in the rainstorm disaster risk in Nanjing. The areas with high-risk rainstorm disaster are mainly concentrated in the central part of Nanjing, and the areas with low-risk rainstorm disaster are in the south and north of the city