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Vegetation classification has always been the focus of remote sensing applications, especially for tropical regions with fragmented terrain, cloudy and rainy climates, and dense vegetation. How to effectively classify vegetation in tropical regions by using multi-spectral remote sensing with high resolution and red-edge spectrum needs to be further verified. Based on the experiment in Wenchang, Hainan, China, which is located in the tropical monsoon region, and combined with the ZY-1 02D 2.5 m fused images in January, March, July, and August, this paper discusses whether NDVI and four red-edge vegetation indices (VIs), CIre, NDVIre, MCARI, and TCARI, can promote vegetation classification and reduce the saturation. The results show that the schemes with the highest classification accuracies in all phases are those in which the red-edge VIs are involved, which suggests that the red-edge VIs can effectively contribute to the classification of vegetation. The maximum accuracy of the single phase is 86%, and the combined accuracy of the four phases can be improved to 92%. It has also been found that CIre and NDVIre do not reach saturation as easily as NDVI and MCARI in July and August, and their ability to enhance the separability between different vegetation types is superior to that of TCARI. In general, red-edge VIs can effectively promote vegetation classification in tropical monsoon regions, and red-edge VIs, such as CIre and NDVIre, have an anti-saturation performance, which can slow down the confusion between different vegetation types due to saturation. [ABSTRACT FROM AUTHOR]

Calcareous interbeds control the migration of oil and water in marine strata. However, in China, the origins of such calcareous interbeds have not been investigated in detail. In this paper, we present a study of calcareous interbeds in marine strata of the Zhujiang Formation in the Wenchang Oil Field, which is located in the southeast of Hainan Province, China. The lithological characteristics, types and features of diagenesis, and formation of the calcareous interbeds were investigated using core, thin-section, scanning electron microscopy, and cathodoluminescence observations, and stable carbon and oxygen isotope data. The calcareous interbeds consist of mixed sediments, which are dominated by bioclastic limestones containing terrigenous clasts, along with subordinate calcareous sandstone. The interbeds are densely cemented. The bioclasts are dominantly brachiopods, pleopods, and foraminifera, with minor amounts of echinodermata, bivalves, red algae, ostracods, and bryozoa. Diagenesis involved calcitic cementation, associated with relatively weak compaction. Carbon and oxygen isotopic data indicate the pore water that formed the carbonate cement was mostly sourced from seawater and minor amounts of meteoric water. The degree of carbonate cementation was significantly related to the bioclast content. On the basis of our study, a genetic model for the macroscopic and microscopic formation of calcareous interbeds is proposed. [ABSTRACT FROM AUTHOR]

The protection of ecological systems is currently a trending topic. Numerous countries have implemented various measures to safeguard ecosystems. Evaluating the effectiveness of regional ecological protection and cooperative conservation is of paramount importance. In this paper, Hainan Island, China, was taken as an example to construct an evaluation framework of the ecosystem change characteristics and conservation effects of different types of protected areas. In this way, the study evaluated the ecological status of important protected areas and the effects of collaborative management and control, and it discussed the changes in ecological status and protection effects. The results revealed the following. (1) Important protected areas occupy a large proportion of natural ecological space, reaching 76.33%, more than twice the proportion of ecological space on Hainan Island. In the past 20 years, the ecological space retention rate has increased by 0.57%. (2) The contribution of excellent-quality and good-quality ecosystems is the greatest, accounting for 82.65% of the whole island. In the past 20 years, the ec7osystem quality has improved in more than 80% of the areas. The proportion of excellent-quality and good-quality ecosystems is as high as 96.75% in these conservation areas, and their contribution to Hainan Island is 44.29%, while conservation areas only account for about 38%. (3) The ecosystem services of Hainan Island have improved and become stable in the past 20 years. The contribution of all types of protected areas to the ecosystem services of Hainan Island is more than 53.22%. In general, the ecological quality and service function has increased in Hainan Island, and the ecological space tends to be stable. Different types of protected areas have effectively protected various ecosystems on Hainan Island with different protection and management mechanisms. [ABSTRACT FROM AUTHOR]

This paper advances theoretical developments in critical toponymies through focusing on the renaming of South China Sea Islands and everyday use of names by fishermen in Hainan, China. Undergoing a series of historical renamings associated with European colonial influences and claims of sovereignty by the Chinese state, multiple official and vernacular toponymic systems co-exist and operate in complex ways in everyday life. By focusing on complexities in the everyday usage of these co-existing toponymic systems, this paper develops calls in the literature to engage with a more complex understanding of the operation of power in naming beyond a focus on a power/resistance dichotomy. Whilst acknowledging the role of political power, it develops this by analysing how renaming is also influenced by social and demographic change, developments in other areas such as heritage, and technological changes, which have received scant attention in the critical toponymies literature. The paper explores the naming of oceanic features to shift the focus of analysis away from the literature's concentration on cities and street names. Overall, the paper argues for a more nuanced and diversified approach to analyzing critical toponymies. [ABSTRACT FROM AUTHOR]

To control heavy metal pollution effectively, prevention of heavy metal accumulations in agricultural soils should be the priority rather than remediation of heavy metal contamination. In this research, papers which contained input and output fluxes of Cd, As, Cr, Hg, and Pb in topsoil (the plough layer) of agricultural lands in Hunan, Zhejiang, the Yangtze River Delta, Hainan, and China as a whole were explored. Fluxes of heavy metal species were recalculated, and future trends of pollution were predicted. Also, cases regarding the application of technologies to control the input and output of heavy metals were analyzed. Results indicated that atmospheric decomposition was the dominant input source of heavy metals in all study sites except Hainan. The relative contributions of fertilizers, irrigation water, and straw returning fluctuated greatly among different sites. Cd pollution in all sites was the most serious, followed by Cr and Pb. In Hunan, Cd has already exceeded the maximum limit value and needs to be controlled urgently. The input of heavy metals from irrigation water, fertilizers, and straw returning could be controlled by proposing more policies to manage their quality and application amounts. The amount of heavy metals absorbed by plants could be increased by cultivating crops with hyperaccumulators and high-biomass plants. [ABSTRACT FROM AUTHOR]

In this paper, an intelligent blind guide system based on 2D LiDAR and RGB-D camera sensing is proposed, and the system is mounted on a smart cane. The intelligent guide system relies on 2D LiDAR, an RGB-D camera, IMU, GPS, Jetson nano B01, STM32, and other hardware. The main advantage of the intelligent guide system proposed by us is that the distance between the smart cane and obstacles can be measured by 2D LiDAR based on the cartographer algorithm, thus achieving simultaneous localization and mapping (SLAM). At the same time, through the improved YOLOv5 algorithm, pedestrians, vehicles, pedestrian crosswalks, traffic lights, warning posts, stone piers, tactile paving, and other objects in front of the visually impaired can be quickly and effectively identified. Laser SLAM and improved YOLOv5 obstacle identification tests were carried out inside a teaching building on the campus of Hainan Normal University and on a pedestrian crossing on Longkun South Road in Haikou City, Hainan Province. The results show that the intelligent guide system developed by us can drive the omnidirectional wheels at the bottom of the smart cane and provide the smart cane with a self-leading blind guide function, like a "guide dog", which can effectively guide the visually impaired to avoid obstacles and reach their predetermined destination, and can quickly and effectively identify the obstacles on the way out. The mapping and positioning accuracy of the system's laser SLAM is 1 m ± 7 cm, and the laser SLAM speed of this system is 25~31 FPS, which can realize the short-distance obstacle avoidance and navigation function both in indoor and outdoor environments. The improved YOLOv5 helps to identify 86 types of objects. The recognition rates for pedestrian crosswalks and for vehicles are 84.6% and 71.8%, respectively; the overall recognition rate for 86 types of objects is 61.2%, and the obstacle recognition rate of the intelligent guide system is 25–26 FPS. [ABSTRACT FROM AUTHOR]

This article offers an introduction to 'After Su Shi', a special issue of Journal of Visual Art Practice, which focuses on the art practice of China's revered poet, calligrapher and stateman, Su Shi (1037–1101). The article situates the work of Su Shi specifically within the context of Hainan, the southern island of China where Su Shi was exiled near the end of his life. Some of his most famous poetry was written during this period and subsequently his identification with Hainan has long endured. Key heritage sites are referenced in this article, and, combined with an overview of the collected papers of the special issue as well as Hainan's recent new status as free port, this introduction sets out both a historical and contemporary view of Su Shi. It elucidates his far-reaching influence but also contemporary 'currency', suggesting of what might come after Su Shi, both in this image, but also akin to his free-spirited belief in the arts. [ABSTRACT FROM AUTHOR]

The assembly and break-up of supercontinents have been hot research topics in international earth sciences because they represent a breakthrough in reconstructing the history of continental evolution and deepening the theory of plate tectonics, which is of indispensable importance to the development of earth sciences. With the continuous enrichment of paleomagnetic, paleontological, chronological, and geochemical data in the last two decades, the evolution of the supercontinent from Columbia to Rodinia has gradually gained unified understanding, and the reconstruction of the major plates within the supercontinent has basically been constrained. In contrast, the reconstruction of microplates, such as South China, Tarim, and Kabul, is controversial and has now become a popular topic and frontier area of supercontinent reconstruction. Hainan lies at the southern tip of South China, and a few Proterozoic units are exposed on the island. At present, Hainan is often taken as a part of the Cathaysia Block. However, due to the lack of exposed Mesoproterozoic igneous and supercrustal rocks in Cathaysia, the reconstruction model of the Cathaysia Block and even the South China Craton based solely on Mesoproterozoic units in Hainan are distinct from those based on units in the Yangtze Block and younger Proterozoic units within the Cathaysia Block, which makes the paleoposition of the South China Craton controversial. In this paper, we provide new detrital zircon U–Pb age data for the Baoban Complex, Hainan, together with the available data to comment on the affinities between Hainan and the Yangtze and Cathaysia Blocks in the Proterozoic, and on this basis, we can reconstruct the South China Craton within the Proterozoic supercontinents. [ABSTRACT FROM AUTHOR]

Based on the analysis of introduction and survival records, this paper reports the status of introduction, survival, and ex-situ conservation of plant species in the South China National Botanical Garden (SCNBG) . The results are as follows: (1) A total of 19 154 species, 99 subspecies and 136 varieties (80 597 accession numbers) of vascular plants belonging to 325 families and 3 952 genera have been introduced since 1956, of which 11 581 species, 52 subspecies and 80 varieties (24 352 accession number) belonging to 290 families and 2 777 genera are surviving currently; the introduction records include 565 species of National Key Protected Wild Plants (421 species survived), covering 94.7% (36/38) of the first-class National Key Protected Wild Plants (29 species survived), 76.4% (269/352) of the second-class National Key Protected Wild Plants (229 species survived), and 54.3% (547/1 008) threatened species (414 species survived) in South China. (2) The most species are introduced from Guangdong Province (7 193 accession numbers, 2 523 species), followed by Hainan Province (3 658 accession numbers, 1 593 species), Guangxi Province (4 744 accession numbers, 1 559 species) and other surrounding provinces; the SCNBG has obtained some precious plant resources from the same latitude regions by introducing and exchanging species with 61 countries around the world. (3) 17 specialized gardens for ex-situ conservation based on plant taxa (e. g. Magnolia Garden) show a high level in terms of introduction quantity and survival rate. (4) The correlation between the number of surviving species and the frequency of introduction is extremely significant (r = 0.85***) . (5) The survival rate of introduced species distributed naturally in South China is higher than that in other provinces. In the future, the SCNBG needs to strengthen the ex-situ conservation of plants through following points: (1) On the basis of investigation, cataloguing, evaluation and research, strengthening the introduction and collection of rare and endangered plants, native plants and economically important plants in tropical and subtropical regions, further improving the quantity and quality of ex-situ conservation; (2) Establishing an ex-situ conservation network system for plants in South China to effectively protect plant diversity in this region; (3) Improving the infrastructure construction and information management level of ex-situ conservation for higher efficiency; (4) Enhancing international scientific research cooperation and species exchange. [ABSTRACT FROM AUTHOR]

With the sustained and rapid development of the economy, the food consumption structure has changed correspondingly and the market of cold and fresh products has developed rapidly, which puts forward the matching of cold chain logistics. Under the background of the construction of the belt and road and the pilot-free trade zone, the organic integration of the fresh agricultural products market and industry in Hainan is facing opportunities and challenges. In particular, in-depth research on the design and planning of the entire logistics system has not been carried out and the research on the distribution vehicle routing problem is still in the initial stage. This paper combs the relevant policies of cold chain logistics development in Hainan province. Given the imperfect system, the lack of policy guarantee measures, and the lack of regionality of the policy objective system, this paper puts forward some suggestions for improvement. The effective inventory control model of Hainan fresh agricultural products under cold chain logistics is explored by using the inventory management theory and the related theory of system dynamics. The simulation is carried out by using Vensim software, which provides a reference for improving the status of cold chain logistics of fresh agricultural products in Hainan. By saving funds, the profits of cold and fresh products are increased and the market competitiveness is improved. [ABSTRACT FROM AUTHOR]

Ethnic villages are an important part of villages, and also the inheritance of ethnic, cultural and spiritual forms. In a certain sense, the overall landscape characteristics of ethnic villages are the epitome of a national culture and image. In this paper, a landscape visualization scheme based on machine learning is proposed by combining the computing form of machine learning with the current visualization system. And use the principle of logistic regression and the principle of support vector calculation to analyze, select the appropriate data set for trend data analysis. Finally, taking the Hlai ethnic village landscape as the research direction in Hainan, the research is carried out in the fields of landscape science and ecology, and the comprehensive analysis is carried out in combination with the national culture, social, ecological and esthetic sensibility, and the Hlai ethnic village's own landscape index system is established. The research shows that the visual system research on the Hlai ethnic village landscape can reflect the Hlai ethnic village cultural landscape to a certain extent and is helpful to the protection and innovation of the Hlai ethnic villages; It is helpful to establish the landscape classification of Hlai ethnic villages and the establishment of future goals; To create their own national cultural landscape for Hlai ethnic villages; At the same time, it helps the sustainable development of Hlai ethnic villages and provides practical methods for the construction of Hlai ethnic villages. [ABSTRACT FROM AUTHOR]

This paper starts from the industrial structure and characteristics of the Internet of Things and compares and analyzes the development ideas of the Internet of Things industry in the market economy under different systems. We also discuss IoT business model innovations and analyze the inadequacies of current IoT business models. We use the cost-benefit analysis method to analyze, from the aspects of social benefits, economic benefits, environmental benefits, and externalities. In this paper, factor analysis and quantitative statistics are used to calculate the weight of influencing factors, and the multilevel fuzzy evaluation method is used to score the influencing factor indicators to calculate the final score result, so as to judge the applicability of the multilevel fuzzy evaluation method to judge the profit model. In order to verify whether the establishment of economic regions plays a positive role in regional economic development, a double-difference model is established. Two sets of data from the Free Trade Zone and Hainan Free Trade Zone are selected for regression analysis, and robustness tests of various methods are carried out. This paper regresses various samples of the Hainan Free Trade Zone by region and city level to explore their characteristics in different regions. From the empirical results, it can be seen that the establishment of the Hainan Free Trade Zone has indeed promoted the economic development of the region where it is located, and this result is still significant after repeated robustness tests. Judging from the regression results by region, the establishment of the Hainan Free Trade Zone has a greater role in promoting the economic development of the eastern and western regions and it has a stronger pulling effect on the western regions than in the western regions. The policy effect of establishing a free trade zone may not be significant due to too few samples and short establishment time. [ABSTRACT FROM AUTHOR]

Hainan Province is in a tropical area of China and previously experienced serious P. falciparum and P. vivax malaria epidemics. After nearly 70 consecutive years of malaria prevention and control, malaria in Hainan has gradually been eliminated. To achieve the elimination of malaria, Hainan enacted six stages: investigative research and pilot prevention and control, large-scale antimalaria measures, adjustment of strategies for prevention and control, joint prevention and control measures, global funding of routine malaria control, and malaria elimination. Different strategies for malaria control were adopted at different stages. Malaria was most prevalent in the mountainous areas of central and southern Hainan, which contain a high-risk population (the forest goers) and two highly effective malaria vectors (An. dirus and An. minimus). Forest goers have been a high-risk population for malaria in Hainan since their identification in the 1990s. This paper summarizes malaria monitoring in forest goers and the response of forest goers to malaria control and elimination, distilling specific malaria control and elimination measures via case studies in Hainan Province. Two case studies in the malaria control stage demonstrated different measures for outbreaks and sporadic cases in forest goers. In view of the malaria outbreak in Sanya during the elimination stage, three-layered strategies (TLSs) were implemented to control outbreaks and improve control measures. Moreover, this paper also illustrates specific management measures to prevent malaria retransmission from sporadic imported malaria cases during the elimination phase. Hainan finally eliminated malaria in 2020. However, the risk of malaria retransmission is still high due to the prevalence of effective malaria vectors in Hainan, and forest goers are still a high-risk population for malaria retransmission. [ABSTRACT FROM AUTHOR]

With the intensification of global environmental pollution and the overexploitation of resources and energy, low-carbon environmental economy (LCEE) has become the important means for countries in the world to achieve sustainable economic, resource, and environmental development. Therefore, the research on the coordinated development of logistics development and LCEE is very necessary in the development of our country's LCEE. Firstly, this paper discusses the development level of logistics industry in Hainan Province from five aspects: energy consumption, carbon emission, carbon productivity, economic benefit index, and carbon emission efficiency. Secondly, choose carbon emission intensity to represent the development level of low-carbon economy. Based on the efficiency coefficient method, coefficient of variation method, linear weighting method, spatial description method, and system evolution equation method, the coordination measurement method is adopted. Finally, the coordinated development of logistics development and low-carbon environmental economy in Hainan Province is analyzed. On this basis, this paper puts forward the related promotion strategies for the coordinated development of logistics development and logistics industry in Hainan. The research results show that the system coupling degree in Hainan Province is about 0.9, indicating that the logistics industry and the low-carbon economic subsystem have a relatively high degree of coupling development. Compared with other provinces, Hainan's level of coupled and coordinated development is at the upstream level. [ABSTRACT FROM AUTHOR]

Aircraft is a crucial mode of transport with several strategic objectives. It is important to detect the position and number of aircraft in remote sensing images accurately. Most of the current research on aircraft detection focuses on improving algorithms or networks based on public datasets or a single remote sensing image, with limited application to large-scale remotely sensed scenes. Moreover, the detection of small and weak targets is challenging for current detection algorithms. This paper proposes a top-down method for aircraft detection in large-scale scenes. First, multi-source data and spatial constraint rules are used to search for potential airport areas in a wide range, and U-Net is then used to extract the airport area. Finally, this paper proposes a feature enhancement faster R-CNN (FEF-R-CNN) by adding a feature enhancement module to the original Faster R-CNN to improve target detection. This can enhance the aircraft feature while suppressing the background information to a certain extent, for effectively detecting small and weak aircraft targets in the airport area. Top-down aircraft detection experiments were conducted on Hainan Island and Shanghai, and 10 of the 12 airports were accurately detected. Meanwhile, the average precision (AP) of aircraft detection by FEF-R-CNN in the public dataset and four large airports in the study area reached 97.71% and 95.63%, respectively, which are 2.14% and 11.31% higher than that of the traditional Faster R-CNN, respectively. Experimental results verify the effectiveness of the proposed method for aircraft detection in large-scale remotely sensed scenes. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to clarify the comprehensive soil fertility status of pitaya orchards in Hainan province, and the spatial distribution and changing trend of soil nutrients in pitaya orchards in Hainan province were analyzed and predicted by means of survey sampling and statistical methods, so as to provide the basis for scientific fertilization and soil management of pitaya orchards.【Method】60 soil samples were collected from pitaya orchards in the main producing areas of Hainan province.Soil pH, organic matter, available nitrogen, available phosphorus, available potassium, exchangeable calcium, exchangeable magnesium, available copper and available zinc were used as evaluation indicators.Inverse distance weight interpolation method（IDW） was used to analyze the spatial distribution of each index, and used the factor analysis method combined with IDW to evaluate and predict the comprehensive soil fertility of the pitaya orchards in the survey area.【Result】The orchard soil in the survey area was neutral and slightly acidic, and 50% of the soil samples, pH were lower than 6.5; The organic matter content was moderately low, and some areas of Ledong and Sanya were insufficient; The average value of alkaline hydrolysis nitrogen was only 79.17 mg/kg, and the soil in the survey area was relatively lack of alkali-hydrolyzable nitrogen; The content of available phosphorus and available potassium were both high, and the average available phosphorus was 119.06 mg/kg, far exceeding its environmental risk threshold（60 mg/kg）; Orchards in the survey area the content of trace elements in the soil was relatively abundant. The IDW prediction map showed that the content of trace elements in Dongfang and Lingshui was high, and the content of Ledong and Sanya was low; Based on the analysis of the comprehensive score IFI, the results of the comprehensive fertility prediction of pitaya orchards in the entire study area using IDW showed that the eastern part of the study area, the comprehensive soil fertility of the orchards in the eastern and western regions of the study area was relatively high, while the soil comprehensive fertility of the orchards in the central part of Ledong and Sanya was relatively low.【Conclusion】The pitaya orchards in Ledong and Sanya still need to increase the input of organic fertilizers or increase the application of lime to improve the soil pH and supplement the medium and trace elements; The orchards in the survey area need to increase the input of nitrogen fertilizer and control the application of phosphate fertilizer. [ABSTRACT FROM AUTHOR]

The echolocation clicks of free-ranging Indo-Pacific finless porpoises (IPFPs, Neophocaena phocaenoides) have been rarely studied in the wild. This paper aims at describing the echolocation-click characteristics of IPFPs and examining whether IPFPs adapt their sonar system to the habitats in Hainan waters, China. The echolocation clicks were recorded using a 13 elements star-shaped array of hydrophones. A total of 65 on-axis clicks were identified and analyzed. IPFPs use echolocation clicks with a source level (SL) of 158 ± 9 dB re: 1 μPa peak-peak, mean peak, and centroid frequency of 134 ± 3 kHz, −3 dB bandwidth of 14 ± 2 kHz and produce at inter-click intervals of 104 ± 51 ms. The results relative to other porpoises show that finless porpoises in Hainan waters produce clicks with moderate SLs and high peak frequency. These results could be useful in detecting the presence and estimating the density of IPFPs during passive acoustic monitoring in the study area and serve to shed light on the interpopulation variation of click characteristics of finless porpoises as well. [ABSTRACT FROM AUTHOR]

The present paper deals with two new species, Atractides (Atractides) bitergumus Zhang & Guo sp. nov. and Atractides (Tympanomegapus) tergumus Zhang & Guo sp. nov., and a new record of a species, Atractides (Atractides) incertus, from Hainan Province, P. R. China. These species are described and illustrated in detail. Article: Atractides (Atractides) bitergumus: Atractides (Tympanomegapus) tergumus: [ABSTRACT FROM AUTHOR]

A three-dimensional electrical conductivity model of the mantle beneath South China is presented using the geomagnetic depth sounding method in this paper. The data misfit term in the inversion function is measured by the L1-norm to suppress the instability caused by large noises contained in the observed data. To properly correct the ocean effect in responses at coastal observatories, a high-resolution (1° × 1°) heterogeneous and fixed shell is included in inversion. The most striking feature of the obtained model is a continuous high-conductivity anomaly that is centered on ~(112° E, 27° N) in the mantle. The average conductivity of the anomaly appears to be two to four times higher than that of the global average models at the most sensitive depths (410–900 km) of geomagnetic depth sounding. Further analysis combining laboratory-measured conductivity models with the observed conductivity model shows that the anomaly implies excess temperature in the mantle. This suggests the existence of a mantle plume, corresponding to the Hainan plume, that originates in the lower mantle, passes through the mantle transition zone, and enters the upper mantle. Our electrical conductivity model provides convincing evidence for the mantle plume beneath South China. [ABSTRACT FROM AUTHOR]

This paper revealed the spatial and temporal distribution characteristics of Chinese marine environmental quality and driving factors during 2003–2021. [Display omitted] • Spatial distribution: South China Sea > East China Sea > Yellow Sea > Bohai Sea. • Shanghai, Zhejiang, Fujian and Hainan maintain high-pollution-low-investment model. • Jiangsu maintains low-pollution-low-investment model. • Typical correlation between Environmental Quality and Socioeconomic is 0.960. • GOP and Per Capita GDP show significant correlation with excellent water quality. As land and sea integration continues to accelerate, it will inevitably have an effect on the marine ecological environment. However, the study on spatial and temporal distribution characteristics of Chinese marine environmental quality and its driving factors was lacking. This paper employs Regression Analysis, Spearman Correlation Analysis, Canonical Correlation Analysis, Boston Consulting Group Matrix and Environmental Kuznets Curve to examine the spatial–temporal distribution characteristics and correlation factors of Chinese jurisdictional sea areas environmental quality. The environmental quality of the waters under China's jurisdiction improved on average from 2003 to 2021, the area of sea with excellent water quality increased by 7.21 × 104 km2. The spatial distribution showed "South superior, North inferior" trend. The accumulated red tide area is 2.01 × 105 km2, and the green tide has the average maximum area of distribution is 3.13 × 104 km2. The marine dumping area's volume of waste has a three stages of slow rise (2003–2007), steady (2008–2014) and rapid rise (2015–2021). The average percentage of seawater bathing areas with good water quality is 82.10 %. Urban Environmental Infrastructure Investment and Urban Drainage Construction Investments are positively correlated with excellent water quality and negatively correlated with light-sewage water quality. The typical correlation for the group "Environmental Quality/Environmental Governance" is 0.911, and the strongest correlation is between excellent water quality and urban drainage construction investment. The typical correlation coefficient for the "Environmental Quality/Socioeconomic" group is 0.960, and the strongest correlation is between excellent water quality and per capita GDP. The Gross Ocean Product, Per Capita GDP, Proportion of Non-agricultural Industries, Year-end Resident Population, and excellent water quality are positively correlated whereas light-sewage water quality is negatively correlated. Liaoning, Tianjin, Shandong and Guangdong shift from high-pollution-low-investment to low-pollution-low-investment model. Shanghai, Zhejiang, Fujian and Hainan maintain high-pollution-low-investment model, Hainan maintains high-pollution-high-investment model. Jiangsu maintains low-pollution-low-investment model. Hebei and Guangxi shift from low-pollution-low-investment to low-pollution-high-investment model. Liaoning, Hebei, Tianjin, Shandong, Guangxi and Shanghai show inverted "N" shape, Jiangsu shows positive "N" shape, Zhejiang and Fujian show monotonic decline shape, Guangdong and Hainan show positive "U" shape. The results could provide valuable suggestions for coastal provinces to accomplish economic development and environmental improvement, which to prevent the old way of "pollution first and treatment later". [ABSTRACT FROM AUTHOR]

The scientific evaluation of tourism resources provides the basic conditions for the rational development and utilization of tourism resources, which is significant for the sustainable development of tourism. On the basis of obtaining a large sample of tourism resource data, this study constructed an evaluation index system of regional tourism resources from four aspects: quantity, type, grade, and a combination of regional tourism resources, taking the township scale as the spatial evaluation unit. The combination weighting method was used to evaluate the grade of tourism resources in each township, and the hierarchical clustering method and spatial autocorrelation method were used to analyze the spatial patterns of the tourism resource values. On the basis of the evaluation's results and spatial pattern analysis, this paper analyzed the influencing factors of tourism resource patterns and puts forward a tourism development model suitable for Hainan tourism development. The results showed that the overall value of tourism resources on Hainan Island was low, and the spatial pattern was obviously different, showing that the northern piedmont plain area was higher than the southern hilly area, and the east coast area was higher than the west coast area. Based on the analysis of quantity density, type abundance, grade advantage, and spatial combination, the tourism resource values of Hainan Island was divided into four combination areas: the first area was diversity and good combination, the second area was large quantity and good combination, the third area was diversity and high-quality resources, and the fourth area was large quantity. In addition, from the analysis of the spatial agglomeration effect, the phenomena of high and low agglomerations of tourism resource values were obvious. Finally, this paper puts forward a tourism development model for Hainan Island by grading, classification, and zoning. The results of this study can determine the time sequence and mode of regional tourism resources development and provide spatial implications and suggestions for regional tourism planning and management. [ABSTRACT FROM AUTHOR]

Background: Medication recommendation based on electronic medical record (EMR) is a research hot spot in smart healthcare. For developing computational medication recommendation methods based on EMR, an important challenge is the lack of a large number of longitudinal EMR data with time correlation. Faced with this challenge, this paper proposes a new EMR-based medication recommendation model called MR-KPA, which combines knowledge-enhanced pre-training with the deep adversarial network to improve medication recommendation from both feature representation and the fine-tuning process. Firstly, a knowledge-enhanced pre-training visit model is proposed to realize domain knowledge-based external feature fusion and pre-training-based internal feature mining for improving the feature representation. Secondly, a medication recommendation model based on the deep adversarial network is developed to optimize the fine-tuning process of pre-training visit model and alleviate over-fitting of model caused by the task gap between pre-training and recommendation. Result: The experimental results on EMRs from medical and health institutions in Hainan Province, China show that the proposed MR-KPA model can effectively improve the accuracy of medication recommendation on small-scale longitudinal EMR data compared with existing representative methods. Conclusion: The advantages of the proposed MR-KPA are mainly attributed to knowledge enhancement based on ontology embedding, the pre-training visit model and adversarial training. Each of these three optimizations is very effective for improving the capability of medication recommendation on small-scale longitudinal EMR data, and the pre-training visit model has the most significant improvement effect. These three optimizations are also complementary, and their integration makes the proposed MR-KPA model achieve the best recommendation effect. [ABSTRACT FROM AUTHOR]

Background: Medication recommendation based on electronic medical record (EMR) is a research hot spot in smart healthcare. For developing computational medication recommendation methods based on EMR, an important challenge is the lack of a large number of longitudinal EMR data with time correlation. Faced with this challenge, this paper proposes a new EMR-based medication recommendation model called MR-KPA, which combines knowledge-enhanced pre-training with the deep adversarial network to improve medication recommendation from both feature representation and the fine-tuning process. Firstly, a knowledge-enhanced pre-training visit model is proposed to realize domain knowledge-based external feature fusion and pre-training-based internal feature mining for improving the feature representation. Secondly, a medication recommendation model based on the deep adversarial network is developed to optimize the fine-tuning process of pre-training visit model and alleviate over-fitting of model caused by the task gap between pre-training and recommendation. Result: The experimental results on EMRs from medical and health institutions in Hainan Province, China show that the proposed MR-KPA model can effectively improve the accuracy of medication recommendation on small-scale longitudinal EMR data compared with existing representative methods. Conclusion: The advantages of the proposed MR-KPA are mainly attributed to knowledge enhancement based on ontology embedding, the pre-training visit model and adversarial training. Each of these three optimizations is very effective for improving the capability of medication recommendation on small-scale longitudinal EMR data, and the pre-training visit model has the most significant improvement effect. These three optimizations are also complementary, and their integration makes the proposed MR-KPA model achieve the best recommendation effect. [ABSTRACT FROM AUTHOR]

Simple Summary: As they are the primary meat goats of Hainan, how to safely and stably transport Hainan black goats through the perinatal period has become one of the major issues. Likewise, anthocyanin-rich Dioscorea alata L. is grown to some extent in Hainan but is wasted in great quantities. The aim of this paper is to explore the effect of Dioscorea alata L. anthocyanins (DAC) on the antioxidant capacity of perinatal Hainan black goats, as well as the possible mechanism on the effect of prior protection, thereby enhancing the reproductive ability of goats and developing characteristic forage resources. Our results indicated feeding a diet in which Dioscorea alata L. powder replaces 30% of corn can increase the antioxidant capacity of perinatal female goats and newborn kids. Furthermore, under H2O2 stress, the use of DAC to treat goat mammary epithelial cells (GMEC) may serve an effective pre-protective function. This will provide data to support the protection of perinatal black goat females and the development of specific food resources. (1) Background: The mammary glands of the perinatal goats are susceptible to reactive oxygen species (ROS) leading to oxidative injury. Although Dioscorea alata L. is rich in anthocyanins with high safety and excellent free-radical-scavenging ability, the effect and mechanism of Dioscorea alata L. anthocyanins (DAC) on the antioxidant capacity of the black Hainan goat has been the subject of few studies to date; (2) Methods: For this reason, feeding experiments were performed by feeding experimental diets, and the pre-protective capacity of DAC on goat mammary epithelial cells was explored on the basis of the established model of H2O2 injury; (3) Results: As well as altering rumen fermentation parameters in perinatal female goats, dietary challenge also improves antioxidant capacity in their blood and milk. thereby enhancing children's antioxidant capacity and increasing their resistance to oxidative stress. However, we also found that DAC pretreatment was capable of activating both Nrf2 and MAPK/JNK pathways, which results in enhanced antioxidase activity and elimination of ROS; (4) Conclusions: Together, these findings suggest that DAC may have a pre-protective role on perinatal Hainan black goats through the regulation of Nrf2 and MAPK/JNK pathways in GMEC. [ABSTRACT FROM AUTHOR]

The ancestral book Genglubu by Liang Qirui, a Hainan fisherman, is rich in contents, but the academic circle has not yet conducted its text sorting. This paper, taking the first chapter "Donghai Genglu" as the research object, sorts out and studies by transcribing the alternating route items, interpreting the missing routes, analyzing the place names and the routes direction. "Donghai Genglu" recorded 56 items and 25 place names. Among them, there are 4 place names of Hainan Island, 9 of Xuande Islands, and 12 of Yongle Islands. The Xisha routes in Liang Qirui’s Genglubu are quite numerous, covering most of the islands and reefs of Xisha Islands, and connecting with the ports of Hainan Island and Nansha Islands. [ABSTRACT FROM AUTHOR]

This study reveals a significant positive connection between autumn non-tropical-cyclone heavy rainfall on Hainan Island and the intensity of Eastern Pacific (EP) El Niño events. That is, the amount of rainfall in super EP El Niño years is more than that in normal EP El Niño years. Comparing EP El Niño years of different intensities, the cooler sea surface temperature in the northwestern Pacific during super EP El Niño years stimulates a negative surface latent heat flux (LHF) anomaly and abnormal anticyclonic circulation at 850 hPa. Under these conditions, an abnormal zonal vertical circulation develops in the northern South China Sea once a positive LHF anomaly and abnormal cyclonic circulation (ACC) at 850 hPa occur in the Beibu Gulf. The abnormal zonal vertical circulation further strengthens the ascending motion over Hainan Island, as the critical factor that leads to excessive rainfall. Further analysis shows that the positive LHF anomaly, which can be attributed to the increased latent heat transfer which resulted from the increased surface wind speed, is an important trigger for the ACC. However, the ACC is also the supplier of favorable moisture conditions because it intensifies vapor convergence over Hainan Island and meridionally transports moisture from the South China Sea to northeastern Hainan Island, thereby generating heavy rainfall. This paper emphasizes that the impact of El Niño events, especially super El Niño events, on rainfall over Hainan Island cannot be ignored, even if the traditional view is that frequent rainfall occurs mainly in La Niña years. [ABSTRACT FROM AUTHOR]

The governments need beforehand to perceive the innovative relationship risk because they are one of the innovation subjects in those industry collaborative innovation alliances. However, it is difficult for innovation subjects to quantify the risks for industry collaborative innovation alliances due to the complexity, nonlinear, and dynamic condition. This paper firstly constructs an ordered logistic model, uses the following as independent variables: the collaborative degree, the ratio of science technology expenditure to GDP, the ratio of education expenditure to GDP, the ratio of finances to GDP, and uses the levels of risk as the dependent variable. Then, this paper uses the panel data of 30 provinces in China (Hainan is not included) from 2010 to 2018 to fit the model. Based on the fitting results, the research has gained the relationship risk prewarning model in industry collaborative innovation alliances by using the collaborative degree as an independent variable. The governments at all levels can use this relationship risk prewarning model to percept risk levels and reckon the corresponding probability which exists in industry collaborative innovation alliances. Furthermore, there are regional influences existing in the prewarning relationship risk levels in industry collaborative alliances. The east and middle areas have significant regional influence, but it does not exist among west areas and others. The governments at all levels may consider the regional differences. [ABSTRACT FROM AUTHOR]

Drift detection is one of the important detection modes in a digital ionosonde system. In this paper, a new data processing method is presented for boosting the automatic and high-quality drift measurement, which is helpful for long-term ionospheric observation, and has been successfully applied to the Chinese Academy of Sciences, Digital Ionosonde (CAS-DIS). Based on Doppler interferometry principle, this method can be successively divided into four constraint steps: extracting the stable echo data; restricting the ionospheric detection region; extracting the reliable reflection cluster, including Doppler filtering and coarse clustering analysis; and calculating the drift velocity. Ordinary wave (O-wave) data extraction, complementary code pulse compression and other data preprocessing techniques are used to improve the signal-to-noise ratio (SNR) of echo data. For the purpose of eliminating multiple echoes, the ionospheric region is determined by combining the optimal height range and detection frequencies obtained from the ionogram. Successively, Doppler filtering and coarse clustering analysis extract reliable reflection clusters. Finally, the weighting factor is brought in, and then weighted least-squares (WLS) is used to fit the drift velocity. The entire data processing process can be implemented automatically without constantly changing parameter settings due to changes in external conditions. This is the first time coarse clustering analysis has been used to extract the paracentral reflection cluster to eliminate scattered reflection points and outer reflection clusters, which further reduces the impacts of external conditions on parameter settings and improves the ability of automatic drift measurement. Compared with the previous method possessed by Digisonde Protable Sounder 4D (DPS4D), the new method can achieve comparable drift detection precision and results even with fewer reflection points. In 2021–2022, several experiments on F region drift detection were carried out in Hainan, China. Results indicate that drift velocities fitted by the new method have diurnal variation and change more gently; the trends of drift velocities fitted by the new method and the previous method are semblable; and this new method can be widely applied to digital ionosondes. [ABSTRACT FROM AUTHOR]

The paper deals with three species, of which one is new to science, Torrenticola (Megapalpis) yii Gu & Guo sp. nov., and two are newly recorded species for the Chinese fanua, Torrenticola (Torrenticola) neoungeri Pešić, Asadi & Smit, 2019 and Neoatractides (Allotorrenticola) malayensis (Wiles, 1991). Torrenticola (Megapalpis) yii Gu & Guo sp. nov. is the second species of Megapalpis in China, and the 21st in the world. Meanwhile, Neoatractides (Allotorrenticola) malayensis (Wiles, 1991) represents a newly recorded subgenus Allotorrenticola from China. [ABSTRACT FROM AUTHOR]

Deep learning methods have been widely studied for Polarimetric synthetic aperture radar (PolSAR) land cover classification. The scarcity of PolSAR labeled samples and the small receptive field of the model limit the performance of deep learning methods for land cover classification. In this paper, a vision Transformer (ViT)-based classification method is proposed. The ViT structure can extract features from the global range of images based on a self-attention block. The powerful feature representation capability of the model is equivalent to a flexible receptive field, which is suitable for PolSAR image classification at different resolutions. In addition, because of the lack of labeled data, the Mask Autoencoder method is used to pre-train the proposed model with unlabeled data. Experiments are carried out on the Flevoland dataset acquired by NASA/JPL AIRSAR and the Hainan dataset acquired by the Aerial Remote Sensing System of the Chinese Academy of Sciences. The experimental results on both datasets demonstrate the superiority of the proposed method. [ABSTRACT FROM AUTHOR]

The sustainable protective efficiency of Casuarina equisetifolia coastal protection forest（CCPF） in Hainan Island has been seriously affected as C. equisetifolia itself can not regenerate naturally. In this paper, Haikou CCPF was taken as the test area of the natural habitat, and a total of 36 treatment combinations were designed by using 5-factor 2-level factor test method to explore the impact factors and barrier factors of C. equisetifolia seed germination and seedling survival. The results were as follows:（1） The treatment combination with the highest seed germination rate of C. equisetifolia was canopy gap-not watering-sandy soil-water retention-covering soil（GJ0 SBM）, with 37.33% of the germination rate, which was significantly higher than those of other treatment combinations（P<0.05）. The treatment combination with the highest average plant height was canopy gap-watering-red soil-no water retention-not covering soil（GJRB0 M0）, with the plant height of 6.43 cm in 53 d, which was significantly higher than those of other treatment combinations（P<0.05）. The treatment combination with the highest survival rate was canopy gap-watering-sandy soil-water retention-covering soil（GJSBM）, with 79.00% of the survival rate for 73 d, which was significantly higher than those of other treatment combinations（P<0.05）.（2） Stand light conditions and covering soil patterns were the impact factors for seed germination rate and germination potential of C. equisetifolia, while water retention patterns had significant effects on seed germination speed.（3） Stand light conditions were the impact factors for C. equisetifolia seedling plant height.（4） Watering treatment was the main factor affecting the survival rate of C. equisetifolia seedlings. In summary, the barrier mechanism of C. equisetifolia natural regeneration unable to survive in Hainan dry season is not for the seed germination, but for the lack of necessary water, resulting in the failure of C. equisetifolia itself natural regeneration. [ABSTRACT FROM AUTHOR]

In order to achieve sustainable development of marine fishery resources, effective supervise of trawl fishing during forbidden fishing period is of great significance. This paper addresses the challenges of poor generalization and the lack of unstructured information in the precise identification of single trawler fishing behavior. We propose a Transformer network with multi-source information fusion processing (MFGTN), which accurately classifies fishing vessels as single trawl or non-single trawl vessels. Firstly, a private fishing dataset of single trawl behavior is constructed by integrating AIS data with radar data, named HaiNan_SingleTrawlVessel(HN_STV). Subsequently, as fused data lacks unstructured information, it undergoes transformation into trajectory point images and recurrence plot images to reveal the internal structure of the fused data. As such, a visual module is introduced to handle the trajectory point images and recurrence plot images as a branch. Simultaneously, the fused data are input into a Double-Tower Transformer with Dual-gate structures to extract information in different dimensions of the time series and feature space as two separate branches. The Fast Attention module replaces the traditional Attention module to improve network speed and reduce memory consumption. Ultimately, the output of the three branches are fused and controlled by a Dual-gate structure that can autonomously learn to determine the network output. Experimental results show that compared to the current best-performing methods, the method discussed herein on the HN_STV dataset has improved the accuracy, recall, precision, and F1-score performance indicators by 2.34%, 2.46%, 0.97%, and 1.39%, respectively. The AUC area on the ROC curve increased by 4%. In a public dataset including three fishing activities, the proposed method improved accuracy, recall, precision, and F1-score by 2.95%, 2.59%, 2.25%, and 2.70%, respectively, and the AUC area on the ROC curve increased by 3%. And in all experiments, our network incurs the lowest time cost. Therefore, the method proposed herein demonstrates its advanced performance. • The HN_STV dataset is constructed, which extracts ship trajectories from the surrounding sea area with Hainan Province as the center, and effectively integrates the ship's AIS data and radar data to create temporal fishing fusion data sequences. • A double-tower Transformer network is proposed to process the information in different dimensions of time series and feature space of temporal fishing fusion data sequences. The traditional Attention module is modified to a Fast Attention module to reduce training time and memory consumption. • A Fusion former visual module is introduced to process the unstructured information of input data, including trajectory point images and recurrence plot images. • A double-layer learnable gate structure is proposed to continuously optimize the weights of different information sources according to the training results of neural networks, so that the network can independently choose the weight ratio of different information sources. [ABSTRACT FROM AUTHOR]

[Objectives] The paper was to study molecular characterization, morphology and pathogenicity of Curvularia pseudobrachyspora, a new causal agent of leaf spot on banana. [Methods] Banana (Musa acuminate') leaves with streaks or long ellipse-shaped lesions were sampled in an orchard of Danzhou City, Hainan Province, China in 2021. Fungus isolates were isolated from the diseased tissues and further identified as C. pseudobrachyspora based on morphological characteristics of colony, conidiophore and spore, phylogenetic analyses of the ITS region, GAP DP and TET-la genes. [Results] In the pathogenicity test, the fungus re-isolated from inoculated leaves with necrotic lesions was identified morphologically and molecularly, fulfilling Koch's postulates. [Conclusions] C. pseudobrachyspora is a new pathogen causing leaf spot of banana in China and the world. [ABSTRACT FROM AUTHOR]

The Penglai sapphires are mainly hosted in alkaline basalts and derived in alluvial sediments. Previous studies have investigated the formation of the Penglai sapphires; however, the genesis of color zoning remains ambiguous. In this paper, we report spectral and chemical composition data of sapphires using ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), and laser-ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS). The results show that the Penglai sapphire has a magmatic origin, mostly showing various shapes of incomplete girdles, barrels, and flakes. The content of Ti in rims is higher than in cores of color-banded sapphire, which results from ubiquitous Ti-bearing inclusions within grown bands. The main chromophore of the deep-blue core is Fe2+-Ti4+, which pairs with Fe3+-Fe3+, Cr3+, and V3+ in the core, likely producing purple-hued blue in an oxidizing environment. The yellowish-brown rim is due to Fe3+ and Cr3+ in a reduced environment. Compared with the basaltic sapphires worldwide, the Fe content is moderately higher than those of most Asian sapphires but obviously lower than those of Changle sapphires in Shandong, China, and overlaps with those of African sapphires. [ABSTRACT FROM AUTHOR]

This paper deals with a new species of genus Parabonzia and newly recorded genus Bonzia from China. Parabonzia bioxys Chen & Jin sp. nov., which is described and illustrated based on adult females collected from rotten wood in Hainan Province, China, differs from all other Parabonzia by the dorsal seta of the palp telofemur having two tines instead of three or more (most species) or being unbranched (P. mindanensisCorpuz-Raros, 1996). Bonzia halacaroidesOudemans, 1927 is redescribed based on adult females collected from fallen leaves in Jiangxi Province and Chongqing City, China, which represents a newly recorded genus BonziaOudemans, 1927 to China and adds more details and new illustrations to its original description. [ABSTRACT FROM AUTHOR]

Seagrass is an important structural and functional component of the global marine ecosystem and is of high value for its ecological services. This paper took Xincun Bay (including Xincun Harbor and Li'an Harbor) of Hainan Province as the study area, combined ground truth data, and adopted two methods to map seagrass in 2020 using Chinese GF2 satellite images: maximum-likelihood and object-oriented classification. Sentinel-2 images from 2016 to 2020 were used to extract information on seagrass distribution changes. The following conclusions were obtained. (1) Based on GF2 imagery, both the classical maximum likelihood classification (MLC) method and the object-based image analysis (OBIA) method can effectively extract seagrass information, and OBIA can also portray the overall condition of seagrass patches. (2) The total seagrass area in the study area in 2020 was about 395 hectares, most of which was distributed in Xincun Harbor. The southern coast of Xincun Harbor is an important area where seagrass is concentrated over about 228 hectares in a strip-like continuous distribution along the coastline. (3) The distribution of seagrasses in the study area showed a significant decaying trend from 2016 to 2020. The total area of seagrass decreased by 79.224 ha during the five years from 2016 to 2020, with a decay rate of 16.458%. This study is the first on the comprehensive monitoring of seagrass in Xincun Bay using satellite remote sensing images, and comprises the first use of GF2 data in seagrass research, aiming to provide a reference for remote sensing monitoring of seagrass in the South China Sea. [ABSTRACT FROM AUTHOR]

Hainan Island is a key part of the eastern Tethyan region and contains detailed geological information that can enhance our understanding of the tectonic evolution of this region since the late Palaeozoic. In this paper, we report geochronological, geochemical, and Sr–Nd isotopic data for granitoids from Baomei and Chahe in the northern part of Hainan Island. Three new zircon U–Pb ages of 243.3 ± 1.7 Ma, 237.1 ± 5.1 Ma, and 257.0 ± 4.0 Ma were obtained for these granitoids. The late Permian Chahe granite (257 Ma) is weakly peraluminous to peraluminous, and has rare earth element patterns and Ga/Al and FeOT/MgO ratios typical of A‐type granites formed in an extensional tectonic setting. The Middle Triassic Baomei granitoids (243–237 Ma) are weakly peraluminous, and exhibit a negative correlation between P2O5 and SiO2, which is typical of I‐type granites. All the granitoids have EM II‐type‐enriched mantle Sr–Nd isotopic compositions, which indicate that they were derived from a mantle source that had experienced enrichment and metasomatism. Hainan Island was in an extensional tectonic setting from the late Permian to Middle Triassic when widespread A‐ and I‐type granites were generated. We speculate that Hainan Island was mainly affected by the Tethyan tectonic domain during the Permian–Triassic, which involved closure of the Palaeo‐Tethys Ocean, collision of the Indochina and South China blocks, and subsequent post‐collisional extension. [ABSTRACT FROM AUTHOR]

Natural disaster response and assessment are key elements of natural hazard monitoring and risk management. Currently, the existing systems are not able to meet the specific needs of many regional stakeholders worldwide; traditional approaches with field surveys are labor-intensive, time-consuming, and expensive, especially for severe disasters that affect a large geographic area. Recent studies have demonstrated that Earth observation (EO) data and technologies provide powerful support for the natural disaster emergency response. However, challenges still exist in support of the entire disaster lifecycle—preparedness, response, and recovery—which build the gaps between the disaster Spatial Data Infrastructure (SDI) already-in-place requirements and the EO capabilities. In order to tackle some of the above challenges, this paper demonstrates how to facilitate typhoon-triggered flood disaster-ready information delivery using an SDI services approach, and proposes a web-based remote sensing disaster decision support system to facilitate natural disaster response and impact assessment, which implements on-demand disaster resource acquisition, on-the-fly analysis, automatic thematic mapping, and decision report release. The system has been implemented with open specifications to facilitate interoperability. The typhoons and floods in Hainan Province, China, are used as typical scenarios to verify the system's applicability and effectiveness. The system improves the automation level of the natural disaster emergency response service, and provides technical support for regional remote-sensing-based disaster mitigation in China. [ABSTRACT FROM AUTHOR]

The Cathaysian Coastal Mountains are thought to be an ancient high‐topographic feature that existed along the margin of South China. They are characterised by extensive Jurassic–Cretaceous magmatism; however, their formation mechanism and timing remains uncertain. In this paper, we present sedimentological and detrital zircon analyses from Cretaceous–Eocene strata and drainage sediments from Hainan Island. Our analyses show a change in provenance from a proximal Cathaysian Coastal arc source in Cretaceous strata to a widely distributed intra‐island granite source in the Eocene strata and modern river sediments. Reconstruction of the crustal thickness evolution for the South China margin from Eu/Eu*‐in‐zircon proxy shows significant crustal thickening during the Late Jurassic–Cretaceous, thereby suggesting the existence of the Cathaysian Coastal Mountains. Together with a compilation of detrital zircon U‐Pb ages in the northern basins of the South China Sea margin, we conclude that the Cathaysian Coastal Mountains extended from the Red River region to Taiwan along the South China margin during the Late Jurassic–Cretaceous and then collapsed/eroded from northeast to southwest during the Eocene–Miocene. This large mountain range supplied detrital sediments to the marginal basins in the northern South China Sea and formed a topographic barrier that prohibited moist Pacific air to reach the relatively arid inland area of South China during the Late Jurassic–Cretaceous. [ABSTRACT FROM AUTHOR]

The Proterozoic geological records in eastern South China preserve a history linked to the Columbia and Rodinia supercontinent cycles and provide key constraints in understanding the geodynamic evolution of East Asia. However, it is uncertain if SW Hainan, Yangtze and Cathaysia were located in the interior or periphery of the Precambrian supercontinents, how they were connected prior to the formation of a united South China, whether the early Neoproterozoic Proto-Huanan subduction was long- or short-lived, and how and when Yangtze and Cathaysia were assembled along the Jiangnan Orogen. This paper provides an overview of key geological observations for the eastern Yangtze and Cathaysia with respect to Proterozoic tectonics. Our synthesis shows that the SW Hainan in the Mesoproterozoic (ca. 1.45 Ga) developed in a non-orogenic rift setting in the interior of Columbia. SW Hainan, together with SW Yangtze, drifted to the margin of Rodinia by ∼1.05 Ga. Furthermore, SW Hainan might have been part of the Mesoproterozoic Albany Fraser Orogen at ca. 1.30–1.05 Ga. Cathaysia and eastern Yangtze display distinct geological signatures in the early Neoproterozoic and Cathaysia remain separated from Yangtze until at least ca. 1.0 Ga. The ca. 1.0–0.9 Ga felsic igneous rocks in Cathaysia to the east of the Jiangshan-Shaoxing suture zone are mostly characterized by negative ε Hf (t) values, and distinct from those in the coeval Shuangxiwu arc to the west of the Jiangshan-Shaoxing suture zone, which have positive ε Hf (t) values. Igneous rocks dated at ca. 870–830 Ma (mainly ca. 850–830 Ma) are extensive in the Huaiyu and Jiangnan Orogen but poorly developed in Cathaysia. Neoproterozoic sedimentary rocks of Cathaysia contain abundant ca. 980 Ma detrital grains but only minor ca. 860–830 Ma grains. In contrast, in the Jiangnan and Huaiyu, the sedimentary rocks contain a dominant ca. 860–830 Ma detrital zircon age-peak but ca. 980 Ma grains are scare. Rift-related bi-model igneous rocks, ranging in age from ca. 810 Ma to ca. 750 Ma, represented by the Banxi, Likou and Mamianshan groups and their equivalents, are extensively developed in Cathaysia and Huaiyu, and the Jiangnan Orogen. These rift-related successions are separated from the Cangshuipu and Luojiamen conglomerates across an angular unconformity, which are in turn unconformable on the Lengjiaxi and Xikou groups. It is herein proposed that an early Neoproterozoic (ca. 1.0–0.9 Ga) accretionary orogen developed within the Cathaysia and lay along strike from the synchronous Eastern Ghats Orogen of India. A long-lived Neoproterozoic (ca. 0.97–0.83 Ga) Proto-Huanan arc-trench system resulted in the development of the ca. 0.98–0.88 Ga Shuangxiwu intra-oceanic arc, ca. 0.87–0.83 Huaiyu continental arc and ca. 0.87–0.83 Jiangnan intra-continental back- arc basin in response to the ongoing westward-subduction beneath the eastern Yangtze. At ca. 0.87 Ga, the arc-trench system switched from an intra-oceanic to a continental Andean margin setting. Such a system might be compatible to the NW India South Delhi Orogen at the periphery of Rodinia. Our synthesis shows that the united proto-South China was finally created by the ca. 830–810 Ma assemblage of the Yangtze with Cathaysia along the Jiangnan Orogen and was followed by the post-orogenic rifting due to the breakup of Rodinia. [ABSTRACT FROM AUTHOR]

Traditional settlements are widely concerned by academic circles for their unique settlement patterns, exquisite residential buildings, and rich historical and cultural connotations, and their protection and development is an important proposition for rural revitalization. Therefore, from the perspective of big data mining (BDM), this paper explores its application in architectural space and settlement protection of traditional settlements in Hainan and provides new ideas for the protection and renewal of traditional settlements in Hainan. The attribute elements of spatial data of settlement groups are analyzed by the decision tree classification mining method. In order to avoid the multivalued tendency of ID3 algorithm and improve the efficiency of decision tree generation by ID3 algorithm, an improved ID3 algorithm is proposed by introducing user interest and simplifying the calculation process of the algorithm. At the same time, the graph theory recognition method of grid pattern is proposed. Aiming at the intersection graph and direction relation graph of straight line pattern, grid pattern recognition is realized by solving the connectivity, intersection, and subsequent construction of the maximum complete subgraph. Experiments show that the improved ID3 algorithm has better running efficiency than the parallel algorithm based on cooccurrence matrix. The analysis of the architectural space of traditional settlements in Hainan will help us better grasp social activities and provide direction for the protection and renewal of traditional settlements from the perspective of tourists and residents. [ABSTRACT FROM AUTHOR]

Nearly three decades ago two new species belonging to the genus Paratrichius Janson, 1881 were described from Hainan Island (SW China): Paratrichius papilionaceus Ma, 1990 and P. rufescens Ma, 1990. The present paper increases the number of Paratrichius species known from Hainan Island to four, with the description of a new species (P. pilosus Ricchiardi and Lu, n. sp.), and a new regional record for P. elegantulus (Moser, 1902), thus far known from N Indochina and continental SW China only. Additionally, Paratrichius papilionaceus Ma, 1990 is here proposed as junior synonym of Paratrichius marmoreus (Moser, 1902), described from northern Vietnam (n. syn.), and Paratrichius brevifolius Kobayashi and Fujioka, 2013, described from northern Vietnam, is here proposed as junior synonym of the above cited Paratrichius elegantulus (Moser, 1902) (n. syn.). Among the four Paratrichius species now listed from Hainan, two (P. pilous and P. rufescens) are very likely endemic to the island's highlands, while other two inhabit the highlands of northern Vietnam, too. [ABSTRACT FROM AUTHOR]

[Objectives] The paper was to identify the causal agent of leaf spot of banana in Hainnan, China. [Methods] Fungus isolates were isolated from the diseased tissues, and morphological characteristics of colony and spore were observed. Furthermore, phylogenetic analyses and pathogenicity test were conducted to confirm the pathogen. [ Results] The fungus isolates from the diseased tissues was identified as Curvularia geniculata. [Conclusions] C. geniculata is a new pathogen causing leaf spot of banana in Hainan, China. This finding will help to broaden the distribution and host range of C. geniculata, indicating that it poses potential damage to banana in China. [ABSTRACT FROM AUTHOR]

In this paper, a stable porous biomass carbon (BC) and gold (Au) nanoparticles modified carbon ionic liquid electrode (CILE) was prepared for the investigation of direct electrochemistry and electrocatalysis of myoglobin (Mb). BC was synthesized via pyrolysis of Hainan's natural tropical plant Lagerstroemia indica leaves, which was modified on the surface of CILE with Au nanoparticles further electrodeposited on the electrode surface. Then, Mb was cast on the nanocomposite‐modified electrode to obtain an electrochemical sensing platform with Nafion film (Nafion/Mb/Au−BC/CILE). Direct electrochemistry of Mb on the modified electrode was investigated with appearance of a pair of enhanced redox peaks, indicating direct electron transfer rate of Mb was accelerated due to the presence of Au−BC nanocomposite. Au−BC nanocomposite exhibited high conductivity, good biocompatibility, and large surface area, which was beneficial for electron transfer of Mb. The Mb modified electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid (TCA) and sodium nitrite (NaNO2), which was further used to establish a new electroanalytical method with satisfied sensitivity in real samples analysis. [ABSTRACT FROM AUTHOR]

This paper builds a new small-scale and regionalization DSGE model that focuses on the sustainable economic system, which was estimated by the Bayesian estimation method using Chinese annual data from 2004 to 2017 to analyze the effect of the fluctuation of fruit prices in Hainan. We find the fluctuation of increasing prices has a negative effect on fruit output. This results in a preference to loosen monetary policy to reduce this influence and then results in price inflation, which will lead to the increase in output and prices simultaneously. Based on our findings, we provide suggestions for policy maker such as the optimization of industrial structures and increased investment in the fruit industry, extending the fruit industry chain and establishing a multifruit industry sustainable economic system. [ABSTRACT FROM AUTHOR]

Hainan is located at the southernmost tip of China, since ancient times it has always occupied an important position on the Silk Road. Hainan culture is dominated by minority and marine cultures and has a rich intangible cultural heritage. Hainan has always been committed to the development and utilization of its wide cultural heritage, and the development direction is mainly based on live display and folk activities. In May 2020, the Chinese government announced the establishment of the Hainan Free Trade Port Policy and System, the establishment of a Hainan International Free Trade Zone, and the development of tourism, modern services, and high-tech industry. All these put forward higher requirements for the protection of Hainan's cultural heritage, not just traditional ways to protect and promote, but also to use the dividends of current scientific and technological development to keep up with the times to protect and promote. The integration of digital technology will be the development direction of cultural heritage and intangible cultural heritage. This paper enumerates and analyzes other cases and academic directions of intangible cultural heritage, combined with the present situation of intangible cultural heritage in Hainan. It also analyzes the predicament of handiwork inheritance in Hainan intangible cultural heritage, expounds the structure, humanistic connotation, and construction skills of Li nationality ship house, and summarizes the role of a novel deep learning convolutional neural network- (CNN-) based virtual reality framework of intangible cultural heritage conservation in promoting the intangible cultural heritage of traditional skills. It also puts forward the scheme and heritage conservation virtual reality content construction and provides the process of building a virtual reality platform for the intangible cultural heritage of ship-shaped houses, which as an example can be used as a reference for intangible cultural heritage researchers in other areas. At the same time, it fills the gap for the artificial intelligence-based digitization of the intangible cultural heritage. [ABSTRACT FROM AUTHOR]

Through a constant market share (CMS) model and a price index model, current research aims to analyze the impetus of the growth of Hainan, China's fruit exports and the adverse impact of rising production costs. This paper considered the changes in the international competitiveness of Hainan's fruit exports and analyzed the reasons for these changes. Additionally, this manuscript analyzed the effects of Hainan's price-bargaining power on fruit exports under the condition of asymmetric information by applying a two-tier stochastic frontier analysis model. The results show that the rising costs of labor led to the gradual loss of price advantage, and the contribution of competitiveness to the growth of Hainan's fruit exports has rapidly declined. The results also indicate that the degree of information held by both importers and Hainan has an important influence on the final exporting price, whereas the importers hold more information and have stronger price-bargaining power than Hainan. Policy suggestions based on the results are proposed. [ABSTRACT FROM AUTHOR]

Penaeus monodon was one of the three main cultured prawns in the world, which had the characteristics of fast growth, large individual, strong disease resistance, a wide range of temperature and salt, delicious meat, and high market price. Guangdong, Fujian, Hainan, and other places were the main areas for rearing and breeding of Penaeus monodon in China, and the traditional extensive production method was its main production method. As the model’s shortcomings continue to emerge, this water and soil resource-dependent and ecologically destructive production method had become one of the major problems that restricted the sustainable development of Penaeus monodon. Circulating the aquaculture system was the current development direction of advanced aquaculture productivity, but so far there were still few reports on pond aquaculture and related research. In order to explore the feasibility and application development value of Penaeus monodon recirculating aquaculture, two sets of recirculating aquaculture systems composed of a pond, a protein separation unit, an inner circulating fluidized bed, and a circulating pump were designed and constructed in Rudong Base of Institute of Fishery Machinery and Instrument, Chinese Academy of Fishery Sciences in 2019, and the aquaculture experiments were carried out. In the whole breeding process, the aeration aerator assembly was opened, and the water truck aerator was opened in the later breeding stage. The water circulation treatment system operated in the middle and late stages of aquaculture, and the circulation capacity was 26.50 m3/h (middle stage) and 33.00 m3/h (late stage). The amount of sewage discharged was 4%-10% (middle stage) and 10%-12% (later stage) of the aquaculture water body. In this paper, the key equipment was designed in detail and the circulating capacity was calculated, and the water quality condition, the growth of Penaeus monodon culture, the water purification function of protein separation combined device, internal circulating fluidized bed, and other equipment under the corresponding control mode in different culture stages were studied. Finally, the economy of culture operation was comprehensively analyzed. The results showed that the system operated smoothly for 120 days. During the culturing period, dissolved oxygen concentration was 5.30-7.14 mg/L, the pH value was 7.23-8.44, ammonia nitrogen concentration was 0.43-1.38 mg/L (after stable operation), nitrite nitrogen concentration was 0.15-0.56 mg/L(after stable operation). The results indicated that the removal load of suspended solids was (43.19±7.25) g/m3·h, the removal rate of ammonia nitrogen was (9.95±1.90)%, the dissolved oxygen was (9.45±0.87)%, the removal load of ammonia nitrogen was (122.34±22.56)g/m3·d, and the nitrification ability was better in the later stage than in the middle stage. The Penaeus monodon grew normally in the aquatic ecological environment of recirculating aquaculture mode and went through a rapid growth period, a stable growth period, and a slow growth period successively. The final culture density was 3.02 kg/m2, and the high-efficiency culture result was achieved. The final feed coefficient was 1.67, and the income per square meter of a single crop was 211.40 yuan according to the sales price of 70 yuan/kg. After deducting the cost, the profit per square meter per stubble was 34.78 yuan, the annual profit per square meter was 69.56 yuan based on two crops per year, which had achieved good economic benefits. The results show that the Penaeus monodon circulating aquaculture system offers a water quality control method for its growth characteristics and water environment requirements at different stages, realizes scientific feeding, and provides technical support for the application of the Penaeus monodon circulating aquaculture model. [ABSTRACT FROM AUTHOR]

The increasing penetration of renewable energy sources (RESs) in multi-microgrids (MMGs) poses significant challenges to stable operation of the systems, and exploring grid-interactive functionalities of electric vehicles (EVs) is receiving increasing attention. However, current distributionally robust energy management models suffer from convergence inefficiencies when exposed to large amounts of historical data, and typically neglect the multi-period coupling effect of EV user behaviors, which hinder the effective utilization of the highly-potential EV resources. In this paper, a novel distributionally robust energy management model for MMGs is proposed to accommodate the uncertainties of RESs and loads, with the grid-interactive EVs operating in an efficient vehicle-to-grid (V2G) mode. Firstly, a multi-period dynamic EV-connection matrix is formulated to determine the connection and dwell times for EVs interacting with the power systems, which enables the cross-cycle continuity of SOCs. Further, the multi-period coupling uncertainties of accidental EVs disconnections are taken into account. Secondly, the Kohonen neural network-based ambiguity set is constructed without including the entire historical scenarios, where the ambiguous distribution is characterized by the representative scenarios with weights. On this basis, a two-stage distributionally robust optimization model is finally developed, which can be solved iteratively by the extended column-and-constraint generation method until the worst-case cost expectation is obtained. The proposed model was evaluated through simulations on a system comprising four interconnected microgrids from the Hainan provincial power grid. The results demonstrate that the proposed model achieves superior cost efficiency, convergence performance and robustness compared to alternative approaches. • A distributionally robust energy management model is developed to explore the grid-interactive functionalities of EVs. • The multi-period coupling effect of user behaviors is characterized for a more elaborated model of gird-interactive EVs. • The KNN-based ambiguity set is constructed to prevent the DRO model from suffering convergence inefficiency. [ABSTRACT FROM AUTHOR]

Records of the Ming period, especially nautical works and maps, refer to various locations near or along the coasts of Fujian, Guangdong and Hainan. Many of these islands and bays, reefs and rocks have a history of their own, while other places rarely attract the attention of modern scholars. One neglected site is Daxingjian, an uninhabitable mini-islet or rock formation south of Honghai Bay, at the northern rim of the South China Sea. The present article analyzes representative references to this rock in selected navigational texts, local gazetteers, and geographical works of the Ming period, and on selected maps from that era. Above all, it shows that Daxingjian was an important mark for Chinese sailors. The final section of the article briefly turns to Portuguese works, which mention Daxingjian as well, albeit under different names. One question that emerges in the course of this paper relates to the large island of Nan'ao and the Nanpeng Islands: how important were these locations in maritime trade at that time? [ABSTRACT FROM AUTHOR]