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As a fundamental element of global carbon storage, the storage carbon in terrestrial ecosystem is significant for climate change mitigation. Land use/cover change (LUCC) is a main impact element of ecosystems' carbon storage. Evaluating the relation between land use change and carbon storage is vital for lowering global carbon emissions. Taking Hainan Island as an example, this paper employs the InVEST as well as the CA-Markov models to assess and predict how different land use affects carbon storage in various situations from 2000 to 2020 and from 2030 to 2050 on Hainan Island. The influence factors, together with driving mechanisms of carbon storage spatial distribution are quantitatively analyzed as well in this paper. The results demonstrate that, from 2000 to 2020, Hainan Island's net increase in built land was 605.49 km2, representing a growth rate of 77.05%. Over the last 20 years, Hainan Island's carbon storage and density have decreased by 5.90 Tg and 1.75 Mg/hm2, respectively. The sharp rise in built land mainly makes the carbon storage decline. From 2030 to 2050, land use changes on Hainan Island are expected to result in differing degrees of carbon storage loss in various scenarios. In 2050, Hainan Island's carbon storage will decline by 17.36 Tg in the Natural Development Scenario (NDS), 13.61 Tg in the Farmland Protection Scenario (FPS), and 8.06 Tg in the Ecological Protection Scenario (EPS) compared to 2020. The EPS can efficiently maintain carbon sequestration capability, but it cannot effectively prevent cropland area loss. Regarding the carbon storage's spatial distribution, Hainan Island generally exhibits a pattern of high carbon storages in the low and middle carbon storages in the surrounding areas. Areas with high value are primarily located in Hainan Island's central and southern mountainous areas, whereas areas with low value are primarily located in surrounding areas with lower elevations, primarily encompassing built land and cropland. Geographic detection presented the spatial differentiation of carbon storage in Hainan Island is mainly influenced by factors like slope, land use intensity, and DEM, as well as its interaction with other factors is significantly strengthened (p < 0.05). Under the strategic framework of the "carbon peaking and carbon neutrality" goal and the national ecological civilization pilot zone, it is imperative to carefully consider scenarios for ecological protection and farmland protection, adopt ecological regulation models with spatial differentiation, and implement land use policies to improve ecosystem stability, which will contribute to carbon storage loss reduction and ensure food and ecological security. [ABSTRACT FROM AUTHOR]

Hainan Province has the largest ocean areas in China. After decades of efforts, it has accumulated abundant marine basic data, and has built various types, different topics and large-scale marine databases. The construction of Hainan provincial digital ocean environment parameters 3D visualization system can effectively integrate, utilize and share these marine information resources, and support marine management and marine ecological environment protection. The multi-dimensional dynamic visualization of information can provide scientific and effective tools for comprehensive marine management and macro-decision-making in a timely and accurate manner. This paper introduces a digital ocean environment parameters three-dimensional (3D) visualization system based on digital earth sphere model suitable for marine environment parameters three-dimensional visualization display, studies the key technologies of multi-dimensional marine environment parameters visualization based on basic geographic data and remote sensing images, which integrated high-precision Digital Elevation Model (DEM) and satellite images to realize the three-dimensional integration and visualization of marine environmental parameters in the South China Sea, providing data display, multi-temporal dimension comparison and spatial overlay analysis. The functions of statistics and data management provide interactive information services for integrated marine management and decision-making support. [ABSTRACT FROM AUTHOR]

Due to the imbalance in the supply and demand of agricultural land, there is an increasing trend of land resources being remoted utilized across regions. Within the context of regional trade, changes in the agroecosystem service value (ESV) can be used to assess consumer responsibility. However, the embodied flow of ESV and its driving factors have been largely unexplored. This paper, utilizing the latest Chinese multi-regional input-output tables and the equivalence factor method, explores the spatiotemporal characteristics of embodied agricultural land and ESV flow between Guangdong and 30 other provinces, and further seeks to construct three types of embodied ESV models to reveal the driving factors. The findings reveal that during the process of domestic trade in goods and services, Guangdong Province has an inflow of 2.10 × 107 hm2 of land from other provinces, with arable land, forestland, and grassland accounting for 25, 61, and 14%, respectively. Guangdong's utilization of ESV is mainly dependent on external inflows, with minimal local consumption and outflows. The embodied ESV between Guangdong and other provinces is 1626.10 billion yuan, with an outflow of 325.32 billion yuan. The "Y"-shaped region consisting of the northwest, northeast, southwest, and Hainan bears significant potential ESV losses for Guangdong Province. Population growth and the intensity of ESV loss will promote the flow of cropland and forestland ESV, while economic development has a certain inhibitory effect on ESV transfer. This paper provides a new analytical perspective on issues such as the spatial distribution mismatch of land resources and ecologically unequal exchange. These insights are pivotal for promoting sustainable utilization of land resources and regional equity. [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]

An intelligent high‐definition and short‐term prediction of ionograms with/without Spread‐F for the observation at Hainan (19.5°N, 109.1°E, magnetic 11°N) is presented in this paper, which comprises a spatio‐temporal ConvGRU network and a super‐resolution EDSR network. Our prediction is based on spatio‐temporal features in the ionogram graph only. There are 469,227 ionograms classified into 5 categories, that is, frequency/range/mix/strong range/no Spread F, over a solar cycle (14 years) labeled manually by the research group, and we process these ionograms into two data sets for training the two networks mentioned above. A series of comprehensive experiments have been designed and conducted to determine the optimal super‐parameters. Our method inputs 8 consecutive authentic ionograms (lasting 2 hr) and generates the next 2 figures (next 30 min). Remarkably, all predicted figures achieve a high accuracy rate of over 94% in predicting the occurrence of Spread‐F. Plain Language Summary: Since the clear trace indicates the ionospheric electron density background and the Spread‐F indicates disturbances/irregularities, the prediction of both ionograms with/without Spread‐F is important to the research and application. There are currently no well‐established neural networks specifically designed to predict the extensive information encompassed within ionograms, particularly the intricate characteristics of Spread‐F. In this paper, we approach the short‐term prediction (next 30 min) of ionograms with/without Spread‐F. To achieve this, we employ the ConvGRU network to generate ionograms blurred but still captured the primary spatio‐temporal features of various types of Spread‐F (FSF/RSF/MSF/SSF) in ionogram sequences, as well as features without Spread‐F. Subsequently, we refine these rough images by EDSR network to obtain clear and detailed predictions. Our treatment to blurred prediction figures and our focus on the Spread‐F key area are innovative. Through our work, the auto‐prediction for ionosonde observation benefits ionosphere research and monitoring. Key Points: Rather than numerical prediction methods, our prediction is based on spatio‐temporal features onlyPredicting high‐definition ionograms by combining ConvGRU and EDSR on the basis of establishing two ionogram data setsAchieving a high accuracy of 94.28% for Spread‐F prediction [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 genus Mullederia (Acariformes: Stigmaeidae) are free-living predatory mites with six species known in the world. In this paper, we describe and illustrate a new species, Mullederia hainanensissp. nov., from deciduous broad-leaved plants and evergreen broad-leaved plants in Hainan Province, China. Moreover, an identification key is provided for the known species of this genus. [ABSTRACT FROM AUTHOR]

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]

An intelligent Spread‐F image detection and classification method is presented in this paper based on an ionogram image set using deep learning models. The ionogram images from the Hainan station, spanning from 2002 to 2015, have been manually labeled into five categories, resulting in a unique ionogram image set for supervised learning models. To balance the number of different types, simulated noises were added to these images. Based on 80,000 samples with Spread‐F and 20,000 samples without, numerous experiments have been conducted to train VGG, ResNet, EfficientNet, ViT, MobileNet, and other networks. The results on the test set indicate that these models except VGG have a good ability of exacting features of different types, leading to a high level of accuracy in detecting Spread‐F and a relatively accurate classification of it. The ionogram images in 2016 are then employed as another test set to further examine the performance of the trained models. Both quantitative and qualitative analyses have demonstrated the results obtained by deep learning models are highly consistent with manual identification. Plain Language Summary: The study of ionospheric Spread‐F (SF) is of great scientific significance and practical value, particularly concerning the correlation between low‐latitude ionospheric scintillation and SF. Our research aims to develop an intelligent SF detection and classification method based on deep learning with high accuracy. It can greatly assist in auto‐analyzing ionogram images rather than manually. While deep learning models (particularly DCNNs) came to be used for SF detection, most of them were incapable of distinguishing SF types, such as FSF/RSF/MSF/BSF/SSF. Moreover, these models were not built on a large data set. Considering the strong regional and temporal variation features of SF occurrences and patterns, samples must cover various situations. The number of ionograms produced by ionosonde at Hainan station from 2002 to 2016 is nearly 520,000. We have manually classified these images into five categories (no SF and 4 types). On this basis, we did this research. The deep learning models in our paper perform well, with most of them being able to extract the features of different types precisely. Our research provides a handy tool for automatically classifying FSF/RSF/MSF/SSF based on image features only, without considering the ionogram data format or the auto‐models in ionosonde. Key Points: A deep learning technique based on image features only, no matter the ionogram data format or the auto‐models in ionosondeBuilding a new image set based on 517,331 manually labeled ionograms including 42,608 Spread‐F samples from one station over one solar cycleBoth quantitative and qualitative analyses have demonstrated the effectiveness of the proposed method [ABSTRACT FROM AUTHOR]

This paper used dynamic image analysis (DIA) to analyze the grain size and shape data of beach surface sediments in Bao'ding Bay, eastern Hainan Island, China, and explored the effects of sediment transport modes and beach morphology on the grain size–shape trend curves. This paper adopted a method of combining grain size cumulative frequency curves and grain size–shape trend curves to identify three sediment transport modes: suspension, saltation, and traction, and analyzed the characteristics of the grain size–shape trend curves under different beach morphologies (reflective, intermediate, and dissipative). This paper found that the grain size–shape trend curves can effectively indicate the sediment transport modes and improve the accuracy of subpopulation division; the grain size–shape trend curves showed different distribution characteristics in the cross-shore and longshore directions, which are closely related to the beach's morphology and sediment transport direction. This paper provides a new method and idea for studying beach sediment transport and sedimentary environment using sediment grain size and shape data. [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]

In Guangxi, Hainan, and Fujian Province in southern China, β-thalassemia is a frequent monogenic hereditary disorder that is primarily defined by hemolytic anemia brought on by inefficient erythropoiesis. It has been found that ineffective erythropoiesis in β-thalassemia is closely associated with a high accumulation of Reactive oxygen species, a product of oxidative stress, in erythroid cells. During recent years, ferroptosis is an iron-dependent lipid peroxidation that involves abnormalities in lipid and iron metabolism as well as reactive oxygen species homeostasis. It is a recently identified kind of programmed cell death. β-thalassemia patients experience increased iron release from reticuloendothelial cells and intestinal absorption of iron, ultimately resulting in iron overload. Additionally, the secretion of Hepcidin is inhibited in these patients. What counts is both ineffective erythropoiesis and ferroptosis in β-thalassemia are intricately linked to the iron metabolism and Reactive oxygen species homeostasis. Consequently, to shed further light on the pathophysiology of β-thalassemia and propose fresh ideas for its therapy, this paper reviews ferroptosis, ineffective erythropoiesis, and the way they interact. [ABSTRACT FROM AUTHOR]

Bai Yuchan's Taoist thought is an important part of Taoist health-preserving thought. Excavating, sorting out, and translating Bai Yuchan's Taoist thought will not only help increase cultural self-confidence and protect traditional culture but also become an important medium for foreign exchanges. With the advent of the digital age, artificial intelligence has helped the dissemination of excellent traditional Chinese culture with its unique technological advantages, improving the effectiveness, intensity, and breadth of cultural dissemination. In domain machine translation, whether domain terms can be correctly translated plays a decisive role in the translation quality. It is of practical significance to effectively integrate domain terms into neural machine translation models and improve the translation quality of domain terms. This paper proposes a method of incorporating new Bai Yuchan's thought term information as prior knowledge into neural machine translation. Using the term dictionary constructed from Bai Yuchan's thought bilingual terminology knowledge base as a medium, two different knowledge integration methods are proposed and compared: (1) term replacement, which means using the target term to replace the source term on the source language side, and (2) term addition, which means splicing the source term and the target term on the source language side and both the source language side and the target language side. Use identifiers as special external knowledge to identify the beginning and end of the target term. Based on the Chinese-English bilingual alignment corpus of New Bai Yuchan's thoughts and the constructed Chinese-English alignment termbase, the experiments are carried out. The results show that on the test set, the BLEU value of the proposed method is 6.38 and 6.38 higher than the baseline experiments, respectively, which proves that the proposed method can effectively incorporate domain terminology knowledge into the translation model and improve the translation quality of domain terminology. [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]

Rehabilitation mobility has become a new demand and travel mode for people to pursue active health. A large number of tourists choose to escape the cold in warm places to improve their health every winter. In this study, we collected the health index data of Seasonal Affective Disorder (SAD) tourists from western China before and after their cold escape in Hainan Island in winter, aiming to compare whether rehabilitating cold escape can improve the Quality of Life (QOL) of SAD tourists by hierarchical analysis. Compared with previous studies, this paper has the following contributions: Firstly, the study samples were accurately screened according to the pathogenesis of SAD tourists and the confounding factors were strictly controlled; Secondly, the observational experimental method was used to conduct intergroup and intra-group control studies on 695 samples, and the results were more objective and reliable. Thirdly, the effect of treatment on the quality of life (QOL) of 397 tourists in the rehabilitation mobility group was quantitatively evaluated from three factors including age, gender and sunshine exposure level by multivariate analysis of variance. Research results show that the rehabilitation environment brought by rehabilitation activities can help improve the health status of tourists. Therefore, this paper proposes the concept of “Tourism Therapy” and constructs a theoretical framework. The conclusion of this paper provides a scientific basis and reference for the study of tourism healing as a non-medical alternative therapy. [ABSTRACT FROM AUTHOR]

Enhancing rural ecological protection and promoting the adoption of environmentally-friendly agricultural production practices largely depend on the implementation of green production methods by farmers. This research paper focuses on the green production behavior of farmers in Hainan Province, China, drawing insights from survey responses provided by 543 farmers. The study examines how farmers' capital endowment, ecological cognition, and environmental regulation impact their multiple green production practices, using the ordered probit model, mediation effect model, and moderation effect model for analysis and further applying the Ivoprobit_CMP, PSM, and other methods for endogeneity treatment and a robustness test. The study reveals several key findings. Firstly, only a small proportion of farmers consistently adopt green production practices throughout various stages of agricultural production. Secondly, the research shows that capital endowment, including natural, economic, human, and social capital, has a significant influence on farmers' green production behavior. Thirdly, the study finds that ecological cognition plays a crucial role in mediating the relationship between capital endowment and its dimensions (human and social capital) and the adoption of green production practices. Additionally, the research discovers that environmental regulation positively moderates the relationship between ecological cognition and farmers' green production behavior. Finally, the research indicates that factors such as ethnicity, fluctuations in agricultural production, and the location of the village agricultural waste collection site are all significant determinants of farmers' engagement in green production practices. The study also identifies significant regional disparities in farmers' adoption of green production practices. To address the issue of farmers' low adoption of green production practices, the paper recommends promoting the overall green transformation of the entire agricultural production process. This can be achieved by enhancing farmers' capital endowment in multiple dimensions and improving their ecological cognition through various channels. Additionally, creating a supportive external environment that aligns with green production practices is deemed critical. [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]

As an important component of forest parameters, forest canopy height is of great significance to the study of forest carbon stocks and carbon cycle status. There is an increasing interest in obtaining large-scale forest canopy height quickly and accurately. Therefore, many studies have aimed to address this issue by proposing machine learning models that accurately invert forest canopy height. However, most of the these approaches feature PolSAR observations from a data-driven viewpoint in the feature selection part of the machine learning model, without taking into account the intrinsic mechanisms of PolSAR polarization observation variables. In this work, we evaluated the correlations between eight polarization observation variables, namely, T11, T22, T33, total backscattered power (SPAN), radar vegetation index (RVI), the surface scattering component (Ps), dihedral angle scattering component (Pd), and body scattering component (Pv) of Freeman-Durden three-component decomposition, and the height of the forest canopy. On this basis, a weighted inversion method for determining forest canopy height under the view of structural equation modeling was proposed. In this study, the direct and indirect contributions of the above eight polarization observation variables to the forest canopy height inversion task were estimated based on structural equation modeling. Among them, the indirect contributions were generated by the interactions between the variables and ultimately had an impact on the forest canopy height inversion. In this study, the covariance matrix between polarization variables and forest canopy height was calculated based on structural equation modeling, the weights of the variables were calculated by combining with the Mahalanobis distance, and the weighted inversion of forest canopy height was carried out using PSO-SVR. In this study, some experiments were carried out using three Gaofen-3 satellite (GF-3) images and ICESat-2 forest canopy height data for some forest areas of Gaofeng Ridge, Baisha Lizu Autonomous County, Hainan Province, China. The results showed that T11, T33, and total backscattered power (SPAN) are highly correlated with forest canopy height. In addition, this study showed that determining the weights of different polarization observation variables contributes positively to the accurate estimation of forest canopy height. The forest canopy height-weighted inversion method proposed in this paper was shown to be superior to the multiple regression model, with a 26% improvement in r and a 0.88 m reduction in the root-mean-square error (RMSE). [ABSTRACT FROM AUTHOR]

Background: The invasive brownrat (Rattus norvegicus) and the Oriental rats (Rattus tanezumi) are common commensal murid that are important hosts for rodent-borne diseases in southeast Asia. Understanding their population structure and genetic diversity is essential to uncover their invasion biology and distribution dynamics that are essential for controlling rodent-borne diseases. Methods: TA total of 103 R. norvegicus and 85 R. tanezumi were collected from 13 to 9 coastal areas of six provincial monitoring sentinel sites, respectivelyto assess patterns in their microsatellite loci and their mitochondrial coxl gene region. Results: Eleven sampled populations of R. norvegicus were divided into two major clusters by region. The observed heterozygosity values of all regional populations were smaller than expected genetic diversity heterozygosity values and deviated from Hardy-Weinberg equilibrium Nine sample populations of R. tanezumi were divided into three clusters; two that included sample from Hainan and Fujian provinces, and one that included samples from the other provinces and cities. The genetic diversity of R. tanezumi was highest in samples from Jiangsu and Guangdong provinces. Conclusion: The data in this paper confirm the two invasive rodent species from the southeastern coastal region of China may have relied on maritime transport to spread from the southern region of China to the Yangtze River basin. R. tanezumi may then hanve migrated unidirectionally, along the southeastern provinces of China towards the north, while R. norvegicus spread in a complex and multidirectional manner in Hainan, Fujian, Zhejiang and Jiangsu Provinces of the country. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to compare the differential impact of Taiwan High-speed Railway (T-HSR) and Hainan East Ring High-speed Railway (HER-HSR) stations on the surrounding construction land expansion, reveal the underlying institutional reasons, and then provide policy recommendations for coordinating the rational development of land resources and ecological environment protection around high-speed railway (HSR) stations. The research methods include the Institutional Analysis and Development (IAD) framework, buffer analysis, and GIS spatial analysis. The results show that (1) The spillover impact of HSR stations on the surrounding construction land expansion is the result of the game between different actors around the development and protection of land around HSR stations under the action scenarios of various external factors. The surrounding construction land of 12 stations of T-HSR increased by 269.98 km2 within the study scope and period, while the surrounding area of 10 stations in HER-HSR increased by 187.61 km2. (2) There are nine stations in T-HSR that affect the expansion of surrounding construction land within 1.0–3.0 km and lead to the expansion of construction land of 22.44 km2, while there are six stations in HER-HSR that affect the expansion of construction land within 1.5–3.5 km and lead to the expansion of construction land of 24.20 km2. Other stations cannot effectively identify their areas of influence due to other reasons. (3) Each station of HER-HSR has a stronger influence intensity and degree on the expansion of surrounding construction land than that of T-HSR, which is closely related to institutional factors such as land planning, land property rights, and public participation. In conclusion, the differences in land planning, land property rights, public participation, and other basic systems will lead to differences in the expansion of surrounding construction land for HSR stations. This research aims to provide institutional adjustment suggestions to achieve coordinated economic development and ecological protection around HSR stations in two Chinese islands with different institutional environments. [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]

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]

The article titled "Drug Resistance and Molecular Characteristics of Carbapenem-Resistant OXA-48-Producing Klebsiella pneumoniae Strains in Hainan, China" has been retracted by the author. Concerns were raised about significant overlap with a previous publication, including identical figures and sequence analyses. The authors admitted errors in their article but were unable to explain the figure overlap satisfactorily. As a result, the Editor-in-Chief decided to retract the paper due to concerns about its reliability. The retraction was approved by the Editor-in-Chief and the authors agreed to it. [Extracted from the article]

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]

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]

China is advocating the ecological civilization for a sustainable society and resource–economic–environmental system due to its environmental and climate problems. As a special resource–economic–environmental system, island systems are facing severe challenges due to the vulnerable coordination ability between ecological environment and economic development. To measure the sustainable performance of island systems more directly and specifically, this paper extends the concept of ecological efficiency to inclusive ecological efficiency. For the first time, we analyze the inclusive eco-efficiency of Hainan Island, the second largest island in China, from 2008 to 2017. Due to the large technological heterogeneity among the diverse industries, this paper combines inclusive eco-efficiency with meta-frontier data envelopment analysis (DEA). And we propose a revised meta-frontier slack-based measure (SBM) model and meta-frontier non-radial directional distance function (NRDDF) model, which makes the technology gap rate (TGR) no larger than 1. The empirical results show that the average inclusive total factor energy efficiency (ITFEE) of the tertiary industry under the group-frontier is the largest while the average ITFEE of the primary industry is the highest under the meta-frontier. Moreover, the technology gap rate of the primary industry is the largest. Policy implementations are presented based on the empirical results. [ABSTRACT FROM AUTHOR]

College students face a variety of challenges today, and the degree of their psychological health directly impacts their ability to overcome these challenges. A good psychological state helps college students to invest better in their career development and improve the degree of social integration. This paper uses the SCL-90 Symptom Self-Assessment Scale and the Social Support Rating Scale (SSRS) to investigate the mental health, psychological support, and social support of students from low income backgrounds in two universities in Hainan City. The research results showed that there was no significant difference between the objective support scores of students from low income backgrounds in higher vocational colleges and non-poor students, while the subjective support and utilization of support scores were significantly lower than those of non-poor students. In essence, successful social support should not only be one-dimensional support from the subject to the object, but should be a process of two-sided interaction, or a process of "mutual construction" between supporters and those supported. According to the research conclusions, this paper suggests how to improve the degree of mental health of college students by way of forming a comprehensive educational environment including campus culture construction, ideological and moral education, and economic assistance system. [ABSTRACT FROM AUTHOR]

Tourism resources are the basic materials of tourism development, and they also provide the support for regional tourism spatial competition. The development of tourism depends on the degree to which tourism resources are utilized, and it is of great guiding significance for their development and utilization to study their spatial structure. Based on a large sample of data on tourism resources, and starting from the characteristics of multi-type, multi-level and multi-combination, this paper puts forward a framework and method for analyzing the spatial structure of tourism resources. Taking Hainan Island as an example, this paper describes the spatial structure of tourism resources in Hainan Island by using the method of point pattern analysis, identifies the tourism resource development zones, and puts forward some suggestions for the development of tourism resources. The results are as follows: (1) The characteristic scale of the spatial structure of tourism resources in Hainan Island is 30.5 km, and there are significant differences in the distributions of all kinds of tourism resources. (2) Through the spatial structure map of tourism resources, the tourism resource development zones are identified, including three tourist central city levels, "one horizontal and three vertical" tourist belts and four tourist combination areas. (3) By combing the distribution of tourism resources and the development zones in Hainan Island, the cross-border characteristics of the tourism resources and development zones are obvious. In order to give full play to the spatial combination and superposition effect of tourism resources, a change from a single isolated development mode to the overall combined development between regions is suggested. On the provincial scale, it is relatively accurate to describe the spatial structure of tourism resources for point data with a large sample size. However, the method of point pattern analysis can not only accurately describe the spatial structure of tourism resources, but it can also provide reference for other types of regional spatial analyses. The research results provide a scientific basis for the spatial planning of regional tourism resources and have practical significance for the development of regional tourism. [ABSTRACT FROM AUTHOR]

The strategy of building an international tourism island in Hainan is an important national strategic deployment, with tourism as the core, integrating a series of issues such as industry, tropical agriculture, and urban-rural relations. The implementation of this strategy profoundly affects the evolution of local land use patterns and ecosystems on Hainan Island. This paper utilizes a counterfactual analysis framework and Cellular Automata (CA)-Markov model based on the current land use data of Hainan Island for the three periods of 1999, 2008 and 2017. Accordingly, the spatial and temporal conditions of ecosystem service values (ESV) in 2017, under the assumed scenario of unimplemented international tourism island strategy, were simulated. The net spatial and temporal impacts of the international tourism island construction strategy on the value of ecosystem services on Hainan Island were finally assessed. The results are as follows. First, the total value of ESV in Hainan Island in 1999, 2008 and 2017 were 33.88 billion yuan, 56.045 billion yuan and 50.417 billion yuan respectively showing a trend of first increasing and then decreasing; spatially, the ESV were high in the central region and low in the surrounding areas. Second, in the simulated scenario without the implementation of the international tourism island construction strategy in 2017, the total ESV of Hainan Island was 54.19 billion yuan. Third, the implementation of the international tourism island policy reduced the ESV by 3773 million yuan, and the impact of this policy was high in coastal areas and low inland. There was an obvious divergence between the positive and negative effects. [ABSTRACT FROM AUTHOR]

This paper proposes an integrated life cycle assessment-life cycle cost (LCA-LCC) model of environmental and economic factors for highway engineering technical schemes to problems such as the limitations of single-dimensional assessment, their narrow scope, the difficulty in tracing sources, and the conflicts of various dimensions in existing integrated assessment methods. The latest documents issued by the Ministry of Ecology and Environment and the Ministry of Transport of China used as an integrated assessment database. Air pollution, water pollution, solid waste pollution, noise pollution, energy consumption, pre-project cost, project construction cost, project operation cost, and post-project cost were used to construct the integrated assessment index system of environmental and economic factors. An improved entropy method was adopted in the LCA-LCC model to overcome the problems of ambiguous results of the previous entropy due to too few assessment schemes, the inoperability of the method when it encounters a negative value or zero value, and unbalanced multi-angle assessments. This model was applied to the assessment of two asphalt pavement maintenance schemes of Highway US280 in Alabama and two improvement schemes of high liquid limit soil subgrade of Highway G360 in Hainan. The results show that the LCA-LCC model overcomes the limitations and imbalances of a single LCA or LCC. The gravel improved scheme and the cold recycling scheme were identified through quantitative assessment as more sustainable. This paper can provide a reference for the comprehensive quantitative assessment of environmental and economic benefits of highway engineering technical schemes. [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]

Surface water quality assessment is an important component of environmental protection and sustainable development. In this study, 24 sampling sites were arranged in the Wanquan River area of Hainan Island, China, in 2021, and nine water quality indicators were measured. The water quality of the Wanquan River was assessed using the single factor pollution index method and the Nemerow pollution index method; the spatial distribution characteristics of pollutants were revealed, and the sources of pollution were further analyzed using factor analysis. The results show that the overall water quality of the Wanquan River basin is good, with the average values of all indicators meeting China's Class III water quality standards. The results of the single factor pollution index method showed that 29% of the sampling sites were in the no pollution class, 38% in the slight pollution class, 25% in the light pollution class, and 8% in the moderate pollution class. The results of the Nemerow pollution index showed that 25% of the sampling sites were in the clean category, 17% in the cleaner category, 42% in the light category, and 17% in the moderate category. The results of the factor analysis show that agricultural activities and domestic sewage discharge are the main sources of pollution, with nitrogen and phosphorus being the most important factors affecting water quality. This paper proposes several measures to reduce water pollution in the Wanquan River, including improving agricultural activities, improving wastewater treatment, and strengthening environmental monitoring. The findings have practical implications for reducing water pollution in rivers and lakes and can provide a reference for policy decisions related to water resource management and environmental protection. [ABSTRACT FROM AUTHOR]

Nature reserves are special habitats established for representative plant and animal ecosystems, and it is important to strengthen the monitoring and protection of nature reserves for ecological environmental protection. In this paper, 23 typical nature reserves of different levels and types on Hainan Island were selected as the study area. The InVEST model and LandTrendr algorithm were applied in habitat quality assessment and to anthropogenic disturbances of the study area from 2000 to 2021, respectively. Finally, an assessment mode was established, coupling the habitat quality assessment and anthropogenic disturbances, to analyze the spatial and temporal conservation effectiveness of the 23 nature reserves. The results indicate that the 23 nature reserves had good overall conservation effectiveness; 21 had an excellent effectiveness rating, and 2 had a good effectiveness rating between 2000 and 2021. Three of the nature reserves, namely, Dazhoudao, Dongzhaigang and Bangxi, have become significantly more effective. Provincial nature reserves are less effective than national nature reserves in terms of conservation, and are a key concern for follow-up. The conservation effectiveness of the four provincial nature reserves—Nanwan, Qinglangang, Dongfangheilianpilu and Qilinlai—is low, and there has been no significant trend of improvement over the past 21 years. The spatial and temporal changes in the conservation effectiveness of 23 nature reserves on Hainan Island over 21 years can provide scientific data support for the development of nature reserves and departmental supervision in Hainan Province. [ABSTRACT FROM AUTHOR]

The construction of the Hainan Free Trade Port (FTP) should not only exploit the advantages of the socialist system with Chinese characteristics but also research and draw on the advanced institutions and successful experience of typical international free trade ports. The emergence of typical international free trade ports in Singapore, Dubai, and Chinese Hong Kong depends on an embedded international economic and trade order and institutional innovation practices. Both conditions are interactively embedded through a series of institutional designs with similar characteristics. The paper sorts out the necessary factors of the successful practice of typical international free trade ports, and proposes that the Hainan FTP should continue to exert its advantages by building on existing institutional innovation. At the same time, it should actively embed the regional multilateral international and economic and trade landscape represented by the Belt and Road Initiative and expedite institutional innovation and reform, and development in different fields, to create a socialist free trade port with Chinese characteristics. [ABSTRACT FROM AUTHOR]

Purpose: The establishment of free trade zones (FTZs) is an important experiment as part of the reform and opening up policy. This paper aims to focus on the issue of production efficiency of environmental protection enterprises in FTZs. Changes in the external and internal environments of enterprises can easily lead to changes in the production efficiencies of enterprises. The establishment of FTZs can change the external environment of enterprises. Knowledge accumulation changes the internal environment of enterprises. However, traditional efficiency analysis has usually ignored the internal and external heterogeneity of decision-making units, resulting in the distortion of the evaluation results. Design/methodology/approach: This paper examines the relationship between knowledge accumulation and development potential based on financial data of environmental protection enterprises that were listed in Shanghai and Shenzhen A stocks, from 2009 to 2016. Then, through data envelopment analysis cross-efficiency analysis of the listed environmental protection enterprises from external heterogeneity, BP neural network model is set up. Findings: The results show that the model set up in this paper is stable and reliable. The paper makes policy suggestions such as stimulating trade inside industry, quickening technological progress and enhancing environmental protection. Originality/value: This paper analyzes the economy, environmental protection, science and technology and education to simulate the external environment of enterprises. Based on the experience data from the completion of Shanghai FTZ, this paper predicts the future development potential of Hainan FTZ enterprises. [ABSTRACT FROM AUTHOR]

Purpose: As a typical resource energy-intensive industry, the scale of construction industry has been expanding rapidly owing to the large-scale urbanization and the economic booming in China, which results in a sharp increase in the energy consumption of construction industry. However, it is infeasible to mitigate the energy consumption by reducing the production activities of construction industry. Therefore, improving the energy efficiency of construction industry is essential for energy saving. Construction industry has close relationships with other industries. The production activities have not only consumed a great deal of energy but they have also generated a massive energy consumption from other industries. Previous literature studied the efficiency of energy consumed directly by the construction industry. However, no research has been found focusing on the efficiency of energy consumed directly by the construction industry and indirectly by the related industries. The purpose of this paper is to put forward a total energy efficiency evaluation framework to measure the energy efficiency of construction industry in depth. Design/methodology/approach: This paper employs the data envelopment analysis (DEA) method and the framework of embodied energy efficiency (EEE) to establish a total energy efficiency evaluation model. Next, the comprehensive analysis of direct energy efficiency (DEE) and EEE in different provinces with various levels of urbanization and various economic levels is conducted. Findings: The results show that the embodied energy intensity and its regularities differ greatly between provinces. From the comparison of DEE and EEE, the provinces of Zhejiang and Jiangsu remain DEA-effective and Hainan is the only province in which the EEE is higher than DEE in 2002, 2007 and 2012. Besides, the DEE and EEE in the provinces with higher levels of urbanization and high economic levels are not more effective than those in the provinces with relatively lower levels of urbanization and low economic levels. Originality/value: Previous literature studied the efficiency of energy consumed directly by the construction industry while ignoring the energy consumed indirectly by the related industries. Besides, no research has been found focusing on the regulation of energy efficiency in different provinces with different levels of urbanization and different economic levels. It can be concluded that the increasing levels of urbanization and higher economic levels have not brought development and benefits for improving DEE and EEE. Therefore, under the condition that the self-regulation of construction industry and market fail to facilitate the improvement of DEE and EEE in China, policymakers should develop policies and market incentive mechanism to encourage construction industry for employing new technologies to improve the energy efficiency. Since the EEE can reveal the energy efficiency in depth, the evaluation method of EEE should be paid more attention. Besides the fact that the EEE is lower than the DEE in almost all provinces, except Hainan province, the industrial structure is essential to develop the EEE. Hence, improving the energy structure, increasing the energy efficiency and developing new and renewable energy are the basic energy strategies in China. [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]

The Low lAtitude long Range Ionospheric raDar (LARID), which consists of two high frequency (HF) radars looking toward the east and west of Hainan Island, respectively, has been developed and installed at Dongfang (19.2°N, 108.8°E, dip lat. 13.8°N), China. This paper describes the system design of LARID and its first observational results of equatorial plasma bubble (EPB) irregularities. The antenna array of LARID is composed of a west‐looking array and an east‐looking array. Each array consists of 20 log‐periodic antennas for transmission and reception and 4 log‐periodic antennas for interferometry, and has a beam steering capability in the azimuth angles of ±24° due the boresight pointing east (or west). Observational results show that the LARID is capable of detecting backscatter echoes from EPB irregularities and the ground, with a distance of 4,000 km or more away from Hainan Island. Multiple EPB structures were continuously observed on 17 April 2023, with eastward drifts ranging between 70 and 130 m/s. Based on ray tracing simulations, the backscatter echoes of EPB irregularities were due to the 0.5‐hop and 1.5‐hop propagation modes. The distances between the successive EPB structures were estimated ranging between 500 and 900 km in longitude. The LARID observations, together with other instruments in the East and Southeast Asian sector, provided a clear picture of longitudinal variation of EPBs in 90–125°E. It is expected that the LARID will provide an important tool to study the generation and evolution of EPBs and their short‐term prediction in East and Southeast Asia. Key Points: A Low lAtitude long Range Ionospheric raDar (LARID) operating at 8–22 MHz has been developed and installed at Hainan Island, ChinaFirst long‐range observations of equatorial plasma bubble (EPB) irregularities and their zonal drifts by the LARID were presentedThe LARID is expected to play an important role in the study of EPB and its short‐term forecasting in East and Southeast Asia [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]

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]

Shallow water cage culture is the main marine activity of Xincun Lagoon, Hainan. However, the continuous growth of aquaculture activities not only aggravates the deterioration of the ecological environment of Lagoon, but also affects the healthy development of mariculture. Suitability analysis on net cage mariculture can reduce the pressure of marine ecological environment, increase the yield of aquaculture and alleviate the conflict between different marine activities to a certain extent. However, the interaction of various factors affecting the suitability evaluation of mariculture constitutes a complex system, and the traditional method of weight determination cannot fit the actual situation well. For this reason, this paper attempts to introduce the interaction matrix of rock engineering systems (RES) to evaluate the weight of each index. At the same time, a multi-criteria decision analysis (MCDA) model based on GIS is established. Finally, a continuous graph of the suitability change of shallow sea cage culture in Xincun Lagoon is obtained. The results show that (1) the entrance area of Lagoon is the most suitable area for cage culture in shallow water; (2) the evaluation results are in agreement with the actual situation and previous studies, and the weight determination method is reasonable and feasible. [ABSTRACT FROM AUTHOR]

This paper proposes a new prediction model for severe natural disasters, especially typhoon using daily weather analysis. Hainan province in China is selected to be a typical application region, where natural disasters, especially typhoons take place frequently. These disasters have great impacts on the life and property safety of the residents, and therefore are in specific need of accurate prediction. A new prediction model of daily weather in Hainan province under the typhoon weather is proposed in this paper based on the best track datasets of typhoons and the corresponding daily weather data. This model utilizes the statistical methods and data mining technology in combination with the dynamic migration information of tropical cyclones and can provide the dynamic prediction of daily weather elements in any designated location. Three surface meteorological observation stations of Hainan province during the years 1951–1920 are used to test the model. Test results show that the prediction equations established for the vast majority of daily weather elements have passed the significant test. Besides, Typhoon Damrey is used as a case to illustrate the whole daily weather prediction model in detail and comparisons between the model and other official forecast (such as JTWC, UKMO and CMA) are performed thoroughly. It is worth noting that the model proposed in this paper is not limited to Hainan province and can be generalized to other areas in the world. [ABSTRACT FROM AUTHOR]

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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]

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]