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The segment assembly problem of shield tunnel in the transition curve part is always a difficult problem in the construction process because of the complex shape of the transition curve and the changeable points of segment assembly. Based on the requirement of staggered assembling and wedge segment characteristics, this paper puts forward a method within the plane to complete every piece of assembling construction by calculating and judging the condition of error control with comprehensive comparison of standard ring and wedge ring combination, and fit out design and varification methods, which meets the specification and control index and guarantees ing uniform linear axis in segment assembling. According to the actual engineering needs, the maximum allowable deviation control method and the segment assembly optimization measures near the slow circle point are proposed, and the accuracy and applicability of the method are proved by the shield tunnel between Wanchai North Station and Wanchai station of Zhuhai Zhuhai-mechanical line, which provides a theoretical basis for the control of segment assembly quality on the transition curve. [ABSTRACT FROM AUTHOR]

The outline of the development plan issued by CPC Central Committee and the State Council for the Guangdong Hong Kong Macao Bay Area clearly pointed out that the Guangdong-Hong Kong-Macao Bay Area should be built into a vibrant world-class urban agglomeration, an international science and technology innovation center, an important support for the construction of the "the Belt and Road," and a demonstration area for in-depth cooperation between the mainland and Hong Kong and Macao; and a high-quality life circle suitable for living, working, and traveling should be created to become a model of high-quality sustainable development. In order to develop the Guangdong-Hong Kong-Macao Bay Area, it is extremely important to enhance the regional business environment. This paper focuses on five influencing factors: policy support, talent guarantee, market supervision, financial support, and cultural promotion. Based on one-way ANOVA and Cobb Douglas function, this paper makes an empirical study on the two important node cities of Zhuhai and Macao. The results show that (1) different factors have different degrees of significant impact on the regional business environment, among which the industry type has the greatest impact, and the duration of enterprise registration has the least impact; (2) when the factors act alone, there is a significant positive correlation between the evaluation dimensions, but most of the correlation degrees are not much different. Finance and talents are the weaknesses of the business environment in the two cities. (3) When the factors are combined, different factors have significant differences in different regions. Zhuhai mainly benefits from policy support, while Macao mainly benefits from market supervision. (4) Regional integration can produce significant association relationship, among which cultural promotion is an important factor. These five important factors have been effectively identified, which have played a leading role in the further design and development direction of the Guangdong-Hong Kong-Macao Bay Area in the future and have an extremely important enlightenment for the study of the business environment in this region. [ABSTRACT FROM AUTHOR]

The accurate prediction of passenger flow is crucial in improving the quality of the service of intercity high-speed railways. At present, there are a few studies on such predictions for railway origin–destination (O-D) pairs, and usually only a single factor is considered, yielding a low prediction accuracy. In this paper, we propose a neural network model based on multi-source data (NN-MSD) to predict the O-D passenger flow of intercity high-speed railways at different times in one day in the short term, considering the factors of time, space, and weather. Firstly, the factors that influence time-varying passenger flow are analyzed based on multi-source data. The cyclical characteristics, spatial and temporal fusion characteristics, and weather characteristics are extracted. Secondly, a neural network model including three modules is designed based on the characteristics. A fully connected network (FCN) model is used in the first module to process the classification data. A bi-directional Long Short-Term Memory (Bi-LSTM) model is used in the second module to process the time series data. The results of the first module and the second module are spliced and fused in the third module using an FCN model. Finally, an experimental analysis is performed for the Guangzhou–Zhuhai intercity high-speed railway in China, in which three groups of comparison experiments are designed. The results show that the proposed NN-MSD model can predict many O-D pairs with a high and stable accuracy, which outperforms the baseline models, and multi-source data are very helpful in improving the prediction accuracy. [ABSTRACT FROM AUTHOR]

With the frequent occurrence of extreme disasters and the development of urbanization, the ecological vulnerability of urban system has been seriously affected, which has become an important issue in urgent need of research. In this study, a comprehensive analysis method of exposure, sensitivity, responsiveness, and resilience was used to establish an ecological vulnerability assessment model based on the impact of typhoon. With the help of big data analysis and model, this paper explored the impact and response of typhoon Hato on Zhuhai's ecological vulnerability and restoration. Our results showed that under the influence of Hato, Jinwan district showed higher vulnerability, followed by Doumen district and Xiangzhou district. The lowest vulnerability of Xiangzhou district mainly for its coping capacity was significantly higher than the other two districts. Judging from the recovery situation shown by big data, Doumen and Xiangzhou districts recovered relatively quickly in terms of hydraulic and communication systems. The results of this study can provide a theoretical reference for vulnerability assessment, predisaster prevention, and postdisaster recovery of typhoon disaster risk areas. [ABSTRACT FROM AUTHOR]

This paper analyzes the vertical ground movement during large-scale pipe roof installation and artificial ground freezing of Gongbei tunnel of the Hong Kong-Zhuhai-Macau bridge project. The transverse ground settlement during pipe roof installation is analyzed. The ground loss volume ratio and settlement trough width coefficient during pipe jacking are estimated based on the field measurement of ground settlement. The interaction of pipes during multiple jacking is investigated. The effect of frost heave control by pregrouting, limiting frozen soil thickness, and combination of the two methods is evaluated. The analysis shows that the ground settlement during pipe roof installation by jacking 37 pieces of 1620 mm steel pipes is relatively small with a maximum value of 2.2 cm. The reinforcement to ground provided by the fore-jacked pipes reduces the ground loss volume ratio and, consequently, the ground settlement during the follow-up pipe jacking. The artificial ground freezing generates a relatively large ground heave with a maximum value of 7.8 cm. Pregrouting plays a critical role in the frost heave control by reducing the heave by about 33%. Limiting the frozen soil thickness by heating pipes serves as an effective supplement to frost heave control by reducing the heave by about 9%. The combination of the two measures reduces the ground heave by about 42%. Findings from this paper provide valuable reference to the tunnel construction using pipe roof and artificial ground freezing as presupport. [ABSTRACT FROM AUTHOR]

Research on carbon emission is an important basis for solving global climate problems, and it is also one of the ways to quantitatively assess the impact of human activities. Cities are one of the main bearing spaces of human activities, and reasonable urban form is conducive to reducing energy consumption in human activities. This paper takes 50 clusters within Zhuhai, China, as the research object, quantifies the landscape spatial form index and social spatial form index of each cluster and establishes the index set of urban spatial form, so as to analyze the influence of different urban spatial form index on carbon emission. The main conclusions are as follows: (1) From the spatial distribution of each index, the urban cluster size and residential building area of each cluster in Zhuhai are generally large, and the distribution is basically consistent with that of densely populated areas. The urban clusters with high dominance are mainly located in the main urban area of Xiangzhou District, and the urban compactness, dispersion and industrial building area are generally high in the west and low in the east. (2) The size of urban clusters, industrial building area and residential building area have a strong promoting effect on carbon emission, while the compactness, dispersion and dominance of urban clusters have a strong inhibiting effect on carbon emission. (3) Based on the above conclusions, the low-carbon urban spatial form optimization strategy should be proposed from three aspects: urban development boundary control, promoting industrial structure transformation and compact urban development. [ABSTRACT FROM AUTHOR]

As the first waterproof component of the immersed tunnel, it is very important to ensure the remaining compression of the GINA gasket to resist external water intrusion. This paper proposed a method for determining warning thresholds for the remaining compression of the GINA gasket based on a material-to-mechanical analysis. In terms of material analysis, two factors that affect the GINA gasket are investigated: rubber hardness and cross-sectional shape, and they are adopted as the basis for subsequent mechanical analysis. In terms of mechanical analysis, uneven settlement during the operation period is considered to be the major cause of joint deformation, which is further divided into four modes: bending, shear, expansion, and torsion, with the computation model of the GINA gasket established to obtain the warning threshold. After that, a graded early warning method is adopted, and corresponding thresholds are given after an investigation of previous studies, which are validated by a three-dimensional finite element analysis. The deformation monitoring data between the E28 and E29 elements of the Hong Kong–Zhuhai–Macao Bridge Immersed Tunnel are used to verify the proposed method. The results show that the GINA gasket of the Hong Kong–Zhuhai–Macao Bridge Immersed Tunnel is currently in a safe state, and its deformation is much lower than the minimum warning level. [ABSTRACT FROM AUTHOR]

Time-varying passenger flow is the input data in the optimization design of intercity high-speed railway transportation products, and it plays an important role. Therefore, it is necessary to predict the origin-destination (O-D) passenger flow at different times of the day in combination with the stable time-varying characteristics. In this paper, three neural network-based hybrid forecasting models are designed and compared, named Variational Mode Decomposition-Multilayer Perceptron (VMD-MLP), Variational Mode Decomposition-Gated Recurrent Unit Neural Network (VMD-GRU), and Variational Mode Decomposition-Bidirectional Long Short-Term Memory Neural Network (VMD-Bi-LSTM). First, the time-varying characteristics of passenger travel demand under different time granularities are analyzed and extracted by the VMD method. Second, three neural network prediction models are constructed to predict the passenger flow sequence after VMD decomposition and reconstruction. Experimental analysis is performed on the Guangzhou Zhuhai intercity high-speed railway in China, and the passenger flow at different time periods of the day under different time granularities is predicted. The following results were found: (i) The number of hidden neurons and the number of iterations of the hybrid forecasting model have a great impact on the prediction accuracy. The error of the VMD-MLP model fluctuates less and it performs more smoothly than both the VMD-GRU model and the VMD-Bi-LSTM model. (ii) The VMD-MLP, VMD-GRU, and VMD-Bi-LSTM models can basically reduce the MAPE error to less than 10%. With the increase of time granularity, RMSE and MAE errors tend to gradually increase, while the MAPE error tends to gradually decrease. (iii) For passenger flow under a smaller time granularity, the prediction accuracy of the VMD-MLP model is higher, while for passenger flow under a larger time granularity, the prediction accuracy of the VMD-GRU and VMD-Bi-LSTM models is higher. (iv) The proposed neural network-based hybrid models outperform the existing models and the hybrid models perform better than the single models. [ABSTRACT FROM AUTHOR]

Compared with the small diameter and the single stratum shield tunnel, the surface subsidence is much greater when the large-diameter shield passes through the upper-soft and lower-hard stratum. In this case, it is particularly important to control the deformation of the embankment when the large-diameter shield passes underneath the embankment. Taking a tunnel project underneath the north embankment in Zhuhai as an engineering example, this paper investigates the deformation characteristics and safety control measures of a super-large-diameter (i.e., 15.80 m) shield tunnel underneath the embankment under complex stratum conditions in upper-soft and lower-hard strata, using on-site monitoring and three-dimensional numerical simulations. The results of the numerical simulation show that grouting can effectively reduce the settlement of the embankment. Grouting is applied to practical engineering, and the monitoring data are in agreement with the numerical simulation results. The surface subsidence of the embankment gradually increases as the shield tail leaves the monitoring section and finally stabilizes. After the shield machine has passed through the embankment, the horizontal deformation troughs on the embankment's surface conform to the Gaussian normal distribution. The maximum settlement occurs in the area directly above the central axis of the tunnel. The deformation trough covers an area about four times the diameter of the tunnel on both sides of its center line. [ABSTRACT FROM AUTHOR]

Solar spectral radiation and underlying surface albedo are important parameters of land surface models. It is significant to study the characteristics of solar spectral radiation and albedo on regions with different underlying surface types for improving the parameterization of land surface models. The underlying surface type of Zhuhai Phoenix Mountain is the evergreen broadleaf forest which represents the typical secondary forest around cities and villages in the Lingnan area in China. We built a tower station with flux, radiation, and meteorological observation system here. In this paper, we selected the radiation observation data from October 2015 to May 2018 to statistically analyze the characteristics of solar spectral radiation and albedo in this area. The results show that the average ratio of near-infrared radiation energy to the solar radiation energy is 51.4% and that of photosynthetic active radiation is 42.8%, while ultraviolet radiation is 5.8%. The average surface albedo of forest canopy to the solar radiation is 0.124 and that to near-infrared radiation is 0.199, photosynthetic active radiation is 0.036, and ultraviolet radiation is 0.026. Compared with the underlying surface albedo of Gobi, sparse vegetation area in Northwest China, the albedo of photosynthetic active radiation on the forest canopy is notably smaller. Further study on the influence factors of albedo shows that the solar elevation angle and air humidity both influence the albedo, when they increase, the albedo will decrease. Based on this relationship, we propose a new two-factor parameterization scheme for albedo, hoping that it can improve the performance of land surface models. [ABSTRACT FROM AUTHOR]

A novel experimental system for studying the macro- and micro-liquefaction behaviors of sand deposits was designed, developed, and applied in this paper. The developed system mainly consists of a shaking table sub-system, a visualized model container, and a fast-shutter-speed micro-image acquisition sub-system. Liquefaction tests on saturated Fujian sand deposit with less permeable Zhuhai clay overburden were conducted to check the performances of the system and study the micro-liquefaction behaviors. Throughout the total liquefaction process, the excess pore water pressures and micro-liquefaction images were recorded and analyzed. It was shown that satisfactory performances can be provided by the developed experimental system. The results showed that the obtained micro-fabrics of sand particles (i.e., the orientations of the contact normal and the long axis of sand particles, the average contact number, and apparent void ratio) agree well with the macro behaviors (i.e., the excess pore water pressure) throughout the total process of liquefaction. Void redistribution during liquefaction was observed beneath the overburden. The developed novel experimental system helps to illuminate the mechanisms of sand liquefaction from the micro-perspective. [ABSTRACT FROM AUTHOR]

Based on real sea conditions of the national wave energy demonstration site in Wanshan sea area of Zhuhai City, China, some numerical experiments are carried out to simulate the submarine cables initial laying process of the Wave Energy Booster Station in this demonstration site. The numerical model is established with the Orcaflex software employed. The motion response of laying ship and the hydrodynamic characteristics of submarine cables are simulated here under three sea conditions, i.e. usual waves, waves with current combined and possible extreme waves. Research results show that the tension and curvature of the cable are large under the condition for wave direction perpendicular to the ship axial direction, which is a relatively bad sea condition. The current also has some influences on the submarine cable laying, and the maximum effective tension of cable produced by the combined wave-current action is 1.35 times that of cable with the wave action alone. When extreme waves appear, pitch, heave and heave acceleration of the laying ship and tension of the cable ends increases obviously. And the variation of effective tension at both cable ends can reach 1.67 times that of cable ends under usual random waves. The numerical model and research results in this paper can provide some guidance for the research and construction of the cable laying of booster stations for marine renewable energy power plants in real sea conditions. [ABSTRACT FROM AUTHOR]

"Ecological man" is an important existing form of the "legal man" mode which generally experiences the rising of the "economic man" and the reflection on the "social man" in terms of its evolution process and Spatio-temporal trajectory, and is now striding toward the "ecological man." In China, it is necessary to implant the core value that is depended on by the "ecological man" into the legislation for the construction of ecology civilization, so as to give a response to the realistic demand on the practice governed by law. After the outbreak of COVID-19, the Local People's Congresses of China launches the revision of the laws and regulations in relation to the prohibition of eating wild animals comprehensively and stresses that prohibition of eating wild animals by legislation is a necessary requirement to guarantee the life, the health and the safety, maintain biological security and ecological safety, strengthen the construction of ecological civilization and promote the harmonious coexistence between human and nature. The Wild Animal Conservation Law that is revised by the Standing Committee of Guangdong Provincial People's Congress stresses, on the one hand, the necessity of comprehensively prohibiting the eating of terrestrial wildlife according to law, and on the other hand, attaches great importance to the response to the social reality appeal and clarifies to make rational compensations to legal breeders for their actual loss. The local legislation on the wild animal conservation adopted in Shenzhen City and Zhuhai City of Guangdong Province clarifies the scope of application for the prohibition of eating terrestrial wildlife and the "white list" of edible animals, and thus stepping in the forefront for local legislation. It can be said that those local legislations above lay a solid foundation for the revision or the formulation of the legislation in connection to the ecological, environmental protection, and public health and safety at the state level and also builds a pleasant atmosphere for the rule of law. In consideration of the unexpected public health and safety issues, this paper stresses that it is essential to see both the surface problem in inadequate legal system supply and the underlying problem in lacking the "ecological man" value idea in the design of legal systems. The implication of the "ecological man" value can be teased from two dimensions that are standard (external) and idea (internal). In view of the so-called "standard" dimension, it attaches greater importance to the practical value of the "ecological man," while in view of the so-called "idea" dimension, it highlights much more on the humanity value of the "ecological man." The practical value of the "ecological man" attaches greater importance to that taking the "common interests of mankind and ecology" as the central value and also as the standard or criteria for the social activities, while the humanistic value of the "ecological man" advocates that the implication of the "ecological man" value lies in a humanistic care. Its value pursuit falls in the legal coordination for multiple interests, to relieve the contradiction and conflict between mankind and nature. [ABSTRACT FROM AUTHOR]

Megaprojects usually involve an alarmingly large number of stakeholders that form a complicated social network and lead to significant relationship risks to client/owners. Therefore, it is necessary to carry out megaproject risk management from a sociological point of view. Based on a case study of the Zhuhai Port, which connects Hong Kong, Zhuhai, and Macao, this paper analyzes the relationship risk between stakeholders and corresponding risk management strategies using social network analysis (SNA). The findings show that stakeholders with a lower density and higher centrality in the network have comparatively a lower relationship risk. Different stakeholders should choose appropriate partners to improve their centrality, reduce the network density to increase their ability to access resources, and enhance their influence and independence in the network. For megaproject client/owners, identifying and monitoring key stakeholders is the key to effective relationship risk governance. The findings provide a number of practical implications for relationship risk management and further demonstrate the importance of stakeholder teamwork, particularly for megaprojects. [ABSTRACT FROM AUTHOR]

The Zhuhai Formation in Lufeng Depression is mainly deposited during a depression stage. In this paper, we employ cores, wireline logs, and seismic reflections to reveal sequence architecture and depositional evolution in target intervals. The results indicated that one second‐order sequence and two third‐order sequences were identified and sequence stratigraphic framework was established. The second‐order sequence was developed in response to base‐level falling, while third‐order sequences were mainly formed during base‐level rising. In addition, each third‐order sequence did not change too much in thickness. Then the shore deposits (shoreface and foreshore) were delineated, and the depositional characteristics were described within the framework with the help of related data. The shoreface and foreshore deposits within the sequence stratigraphic framework varied significantly in stacking patterns of wireline logs and cores. Based on comprehensive analysis, it can be concluded that base‐level changes played an important role in controlling sequence architecture. And lacustrine fluctuations derived from accommodation space changes exerted an essential effect on depositional evolution. This study provides significant insights into revealing the sequence architecture and depositional evolution and discussing hydrocarbon potential in the transition stage in the Zhuhai Formation. [ABSTRACT FROM AUTHOR]

Despite an abundance of representations that focalize Zhuhai's island and coastal features in both academic and popular discourses, serious engagement with the lived sociogeographic realities of the 'city of a hundred islands' are few and far between. As a critical reaction, this paper seeks a relational production of Zhuhai, China as an island city with specific urban island spatiality. The focus/locus problematic is deployed within the wider context of the relational turn in island studies. First, representations that bring Zhuhai's islandness into focus are categorized and analyzed. It is questioned whether these discourses have constructed for the city an organic collective self that identifies with island and marine values. In an effort to de-focus Zhuhai's island and coastal geographies and re-produce them as locus, a series of place-specific relational issues pertinent to urban island studies are addressed, such as the relationship between island spatiality and city formation, land-sea configurations, and the nature of urban public space between land and sea. It is argued that the island city of Zhuhai's imaginaries and the concretization of its island and coastal possibilities follow a trajectory that is island conscious and mainland unconscious. To propose alternative theoretical models for a more nuanced understanding of the lived realities of the island city of Zhuhai and island cities in general, the paper concludes by re-contextualizing the focus/locus dichotomy within the wider theoretical framework of the relational turn in island studies. [ABSTRACT FROM AUTHOR]

In order to develop the strategy more suitable campus-based coronavirus disease 2019 (COVID-19) prevention programs for undergraduate students, it is critical to identify discrepancies in knowledge of COVID-19 prevention among students from different campuses in China. The present study examined the difference in preventive knowledge about COVID-19 pandemic in undergraduate students from two cities of Guangdong-Hong Kong-Macao Greater Bay Area (GBA), Macao Special Administrative Region (SAR), which had very few cases of COVID-19 patients, and Zhuhai, which is borders Macao SAR. In August 2020, two cohorts of undergraduate students from universities in Macao (n = 977) and Zhuhai (n = 2,818) were recruited for online. The self-rating questionnaire was used to gain information about their knowledge in COVID-19 prevention. Macao and Zhuhai students had similar correct rates in terms of heat inactivation conditions of SARS-CoV-2, (76.8% vs. 76.9%, P = 0.950), etiquette when coughing and sneezing (75.9% vs. 75.0%, P = 0.562), and use of disposable masks (92.2% vs. 90.6%, P = 0.126). However, students from Macao had significantly higher rates in correct use of disinfectants against SARS-CoV-2 (24.6% vs. 17.5%, P < 0.001) and in the route of transmission of SARS-CoV-2 (84.5% vs. 79.6%, P < 0.001) than those from Zhuhai. In conclusion, the knowledge level of COVID-19 prevention differs among undergraduate students from Macao and Zhuhai, which warrants an appropriate region-specific health education strategie for COVID-19 prevention. [ABSTRACT FROM AUTHOR]

In the service industry, highway toll collectors serve as a distinctive frontline workforce who frequently encounter mistreatment from customers. Unfortunately, these behaviors have not received the attention and resolution they deserve, resulting in significant physical and psychological stress for toll collectors and exacerbating turnover rates. The study highlights how customer mistreatment affects toll collectors' turnover intentions by performing the sequential mediating roles of stress symptoms and affective commitment and assumes that neuroticism exacerbates the stress symptoms resulting from customer mistreatment based on affective events theory. The model was tested using data collected from 230 highway toll collectors in Zhuhai, China. All hypotheses received support. This study holds both theoretical and practical implications for future research. [ABSTRACT FROM AUTHOR]

Palmate-leaved morning glory (Ipomoea cairica (L.) Sweet) is a fast-growing perennial herbaceous twining vine that was recently discovered to invade mangrove wetlands in China. To understand the mechanism of its successful invasion, the salt tolerance of a coastal ecotype from Zhuhai and a terrestrial ecotype from Guangzhou were compared under salt stress. The morphological, physiological, and biochemical parameters related to growth, ion homeostasis, photosynthetic pigments, chlorophyll fluorescence parameters, oxidative stress, and apoptosis were measured in both ecotypes. Monitoring apoptosis showed that the protoplasts of the coastal ecotype underwent apoptosis and were later compared with those of the terrestrial ecotype. The coastal ecotype was also found to have higher regenerated stems; less water loss, sodium (Na+) uptake, and membrane damage; higher salt gland density and area; and better photosynthetic performance than the terrestrial ecotype. The coastal ecotype probably prevented salt-related damage by reducing its water loss and secreting excess Na+ through its lower stomatal density and higher density and area of salt glands. The coastal ecotype also maintained a better balance of Na+, potassium ions, nitrogen, and phosphorus under salt stress. Moreover, the coastal ecotype had higher activities of antioxidant enzymes, including superoxide dismutase, peroxidase, and catalase, and a higher content of non-enzymatic antioxidants, including proline and anthocyanins, which indicate a stronger antioxidant ability. Our results suggest that the coastal ecotype adapts to a higher salt tolerance than the terrestrial ecotype by enhancing its exclusion of salt, adjusting its osmolytes, and through photosynthetic efficiency, which could explain its successful invasion in the mangrove wetland ecosystem. [ABSTRACT FROM AUTHOR]

Salt intrusion presents a significant environmental challenge in numerous estuaries around the world, including the Modaomen Estuary in China. This phenomenon typically occurs during the winter season due to reduced freshwater flow. However, an unusual salt intrusion event was observed during the autumn of 2022, coinciding with a typhoon. In this study, we assess the response of the Modaomen to Typhoon Nesat in 2022 and examine the influence of the typhoon on salt intrusion using the Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM). The model results reveal that salt intrusion during a typhoon event is primarily driven by the storm surge and landward Ekman transport. Northeasterly winds enhance stratification between saltwater and freshwater in the Modaomen. Moreover, with the typhoon's passage, the Denglongshan Station recorded a peak salinity of 17 psu, with salt intrusion stretching 29 km further. This escalation led to salinity levels surpassing the local drinking water standard of 0.5 psu across all freshwater intake points in Zhuhai City. Numerical experiments indicate that if Typhoon Nesat had occurred during spring tides, the salt intrusion would have been less severe. Furthermore, the study revealed that regulating the upstream runoff could potentially alleviate the effects of typhoon-induced salt intrusion on ensuring a safe water supply. With a runoff increase to 4000 m3/s, the impact of typhoons on Modaomen's drinking water supply can be managed, and at 6000 m3/s, the influence of typhoons on water supply becomes negligible. [ABSTRACT FROM AUTHOR]

The Yellow River Delta wetland boasts a diverse range of vegetation species and harbors an ecosystem that is both sensitive and fragile, so it is of great practical significance to accurately extract the vegetation information and analyze the spatial and temporal changes of this region. Based on the hyperspectral image data of Zhuhai-1, this study selected the characteristic bands through the continuum removal method. It combined these spectral attributes with index-based characteristics, utilizing the random forest algorithm to classify prevalent vegetation types while subjecting the outcomes to thorough analysis. It was shown that (1) when integrating spectral features, red edge indices, water indices, and vegetation indices to classify five distinct vegetation types in the Yellow River Delta during 2020 and 2022, the random forest classification algorithm showed higher classification accuracy, and the study achieved commendable overall classification accuracy rates and Kappa coefficients of 85.92% and 0.84, and 86.25% and 0.84, respectively. (2) In 2020 and 2022, the distribution of vegetation in the Yellow River Delta exhibited the following order: Suaeda glauca > Phragmites > Spartina alterniflora > Tamarisk > Typha orientalis Presl. With the exception of Spartina alterniflora, all categories of vegetation witnessed an increase in their distribution areas. Phragmites experienced the most significant growth, with an area expansion of 9.42%. (3) The ecological restoration and management measures taken in the Yellow River Delta have proven notably effective. The proportion of Spartina alterniflora within the vegetation decreased by 3.45%, the native vegetation showed a resurgence, the distribution pattern of vegetation communities moved toward stability, and the total area of vegetation in the study area exhibited an upward trajectory. [ABSTRACT FROM AUTHOR]

Ground deformation poses an imminent threat to urban development. This study uses the multiscale geographically weighted regression (MGWR) model to investigate the spatial heterogeneity in factors influencing ground deformation, thereby elucidating the drivers behind regional variations in ground deformation patterns. To gain insights into the characteristics of ground deformation in Zhuhai, China, and its spatial relationship with natural and anthropogenic features, we initially utilized the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) method to collect data on ground deformation and its distribution across the entire area. Concurrently, remote sensing imagery was used to identify the various mechanisms affecting ground deformation during the same period, including geotectonic conditions, geographic environment, and human activities. Subsequently, we used the MGWR model to quantitatively estimate the effects of these driving force factors on ground deformation in Zhuhai. Our findings reveal significant ground deformation in specific areas, including Baijiao Town (Doumen District), Hongqi Town (Jinwan District), the Gaolan Port Economic Zone, and the northern part of Hengqin Town, with peak deformation rates reaching 117 mm/y. Key drivers of ground deformation in Zhuhai include NDVI, groundwater extraction intensity, and soft soil thickness. The application of the MGWR model, with an R-sq value of 0.910, outperformed both the global regression model ordinary least squares (OLS), with an R-sq value of 0.722, and the local regression model geographically weighted regression (GWR), with an R-sq value of 0.770, in identifying driving forces. This study can provide valuable insights for government policies aimed at mitigating the disaster risks associated with urban ground deformation. [ABSTRACT FROM AUTHOR]

A rock slope can be characterized by tens of persistent discontinuities. A slope can be massive. The slip surface of the slope is usually easier to expand along with the discontinuities because the shear strength of the discontinuities is substantially lower than that of the rock blocks. Based on this idea, this paper takes a jointed rock slope in Hengqin Island, Zhuhai as an example, and establishes a three-dimensional (3D) model of the studied slope by digital close-range photogrammetry to rapidly interpret 222 fracture parameters. Meanwhile, a new Floyd algorithm for finding the shortest path is developed to realize the critical slip surface identification of the studied slope. Within the 3D fracture network model created using the Monte Carlo method, a sequence of cross-sections is placed. These cross-sections containing fractures are used to search for the shortest paths between the designated shear entrances and exits. For anyone combination of entry point and exit point, the shortest paths corresponding to different cross-sections are different and cluttered. For the sake of safety and convenience, these shortest paths are simplified as a circular arc that is regarded as a potential slip surface. The fracture frequency is used to determine the probability of sliding along a prospective critical slip surface. The potential slip surface through the entrance point (0, 80) and exit point (120, 0) is identified as the final critical slip surface of the slope due to the maximum fracture frequency. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this paper is to describe the design of a radio frequency identification (RFID)-based intra-supply chain (intra-SC) system to facilitate coordination and integration of supply chain functions and activities, thus eventually enhancing the overall performance of a supply chain. Design/methodology/approach - The architecture of the proposed RFID-based intra-SC system is designed specificaiiy for a chain made up of a fiber producer, fiber dyeing producer, yarn spinning producer, knitting and finishing producer, distributor, and a textile retailer. Findings - Compared with the traditional approach, operational time, costs, lead time, and accuracy of inventory holding and of cycle time operations are noticeably improved. Practical implications -. The proposed RFID-based intra-SC system is implemented for trial at a distribution warehouse in Zhuhai, China. It is of benefit to the manufacturer who is able to seek obsolete stock effectively and capture real-time data automatically. Originality/value - The RFIID-based intra-SC system is designed to overcome issues of information invisibility, which is considered a huge cost lost for obsolete stocks and ineffective intra-SC operations in the textile industry. In this industry, the products are highly dependent on seasonal factors. Short product life cycle and high forecast errors are also critical difficulties encountered by supply chain parties. Thus, the RFID technology is suggested to be adopted in similar supply chains. In this paper, a textile manufacturing site is selected to test the proposed RFID system. Some advantages, critical issues for implementation of the RFID system, and lessons learned from the case study are shared with other interested parties. [ABSTRACT FROM AUTHOR]

A new presupporting technology named freeze-sealing pipe roof (FSPR) method was adopted in the construction of Gongbei tunnel (Zhuhai, P.R. China), which was a critical part of Hong Kong-Zhuhai-Macau Bridge (HZMB). The method combined the pipe-roofing with artificial ground freezing (AGF). The water resistance performance of FSPR surrounded by water-rich soils was studied based on the field temperature data. The time-dependent temperature changes of the frozen soil between two adjacent pipes were presented, and the thicknesses of the frozen soil in different freeze period were calculated. Besides, the remote temperature monitoring system used in this field research was presented systematically. The thermal effects of the Hurricane Nicole on the frozen soil wall were also observed. The results showed that the closure of frozen soil wall can be classified into two different modes. The frozen soil between the pipes before excavation had met the design requirements before excavation, and the FSPR maintained satisfied water resistance performance. [ABSTRACT FROM AUTHOR]

Leaf area index (LAI) is a vital parameter reflecting vegetation structure, physio‐ecological process and growth development. Accurate estimation of mangrove LAI is fundamental for assessing the ecological restoration and sustainable development of mangrove ecosystems. To date, very few studies have explored the hybrid method of radiative transfer model (RTM) and machine‐learning model in retrieving mangrove LAI with different satellite sensors. This study investigated the capabilities of combining the PROSAIL‐D model, XGBoost (extreme gradient boosting) and remote sensing images in estimating mangrove LAI, considering the spatial resolutions and spectral vegetation indices (VIs) of Landsat‐8, Sentinel‐2, Worldview‐2 and Zhuhai‐1 images, and further explored the role of eco‐environmental factors in the spatial distribution of LAI in Gaoqiao Mangrove Reserve, China. The results showed that the Zhuhai‐1 acquires the best estimation accuracy (RVal2 (the determination coefficient of validation) = 0.86, RPD (residual prediction deviation) = 3.36 and RMSE (root mean square error) = 0.31), followed by Worldview‐2 (RVal2 = 0.84, RPD = 2.64 and RMSE = 0.33), Sentinel‐2 (RVal2 = 0.34, RPD = 1.33 and RMSE = 0.62) and Landsat‐8 (RVal2 = 0.29, RPD = 1.03 and RMSE = 0.71). The newly developed three‐band VIs (B443−B864/B443+B864−2×B561 with Landsat‐8, B490−B842/B490+B842−2×B705 with Sentinel‐2, B427−B832/B908−B832 with Worldview‐2 and B896−B700/B776−B700 with Zhuhai‐1) were efficient estimators of mangrove LAI. Moreover, elevation and species composition could greatly affect the spatial distribution of mangrove LAI. We concluded that the hybrid method of PROSAIL‐D and XGBoost model using VIs derived from Zhuhai‐1 hyperspectral image could be deemed as basic method and input variables of mapping mangrove LAI, and could be effectively and widely applied in generating mangrove LAI products at the regional and national scales. [ABSTRACT FROM AUTHOR]

The superimposed effects of sea level rise caused by global warming and land subsidence seriously threaten the sustainable development of coastal cities. In recent years, an important coastal city in China, Zhuhai, has been suffering from severe and widespread land subsidence; however, the characteristics, triggers, and vulnerability assessment of ground subsidence in Zhuhai are still unclear. Therefore, we used the SBAS-InSAR technique to process 51 Sentinel-1A images to monitor the land subsidence in Zhuhai during the period from August 2016 to June 2019. The results showed that there was extensive land subsidence in the study area, with a maximum rate of −109.75 mm/yr. The surface had sequentially undergone a process of minor uplift and decline fluctuation, sharp settlement, and stable subsidence. The distribution and evolution of land subsidence were controlled by tectonic fractures and triggered by the thickness of soft soil, the intensity of groundwater development, and the seasonal changes of atmospheric precipitation. The comprehensive index method and the analytic hierarchy process were applied to derive extremely high subsidence vulnerability in several village communities and some traffic arteries in Zhuhai. Our research provides a theoretical basis for urban disaster prevention in Zhuhai and the construction planning of coastal cities around the world. [ABSTRACT FROM AUTHOR]

Accurate registration is an essential prerequisite for analysis and applications involving remote sensing imagery. It is usually difficult to extract enough matching points for inter-band registration in hyperspectral imagery due to the different spectral responses for land features in different image bands. This is especially true for non-adjacent bands. The inconsistency in geometric distortion caused by topographic relief also makes it inappropriate to use a single affine transformation relationship for the geometric transformation of the entire image. Currently, accurate registration between spectral bands of Zhuhai-1 satellite hyperspectral imagery remains challenging. In this paper, a full-spectrum registration method was proposed to address this problem. The method combines the transfer strategy based on the affine transformation relationship between adjacent spectrums with the differential correction from dense Delaunay triangulation. Firstly, the scale-invariant feature transform (SIFT) extraction method was used to extract and match feature points of adjacent bands. The RANdom SAmple Consensus (RANSAC) algorithm and the least square method is then used to eliminate mismatching point pairs to obtain fine matching point pairs. Secondly, a dense Delaunay triangulation was constructed based on fine matching point pairs. The affine transformation relation for non-adjacent bands was established for each triangle using the affine transformation relation transfer strategy. Finally, the affine transformation relation was used to perform differential correction for each triangle. Three Zhuhai-1 satellite hyperspectral images covering different terrains were used as experiment data. The evaluation results showed that the adjacent band registration accuracy ranged from 0.2 to 0.6 pixels. The structural similarity measure and cosine similarity measure between non-adjacent bands were both greater than 0.80. Moreover, the full-spectrum registration accuracy was less than 1 pixel. These registration results can meet the needs of Zhuhai-1 hyperspectral imagery applications in various fields. [ABSTRACT FROM AUTHOR]

Scolecobasidium is cosmopolitan and includes species that inhabit a wide range of ecosystems including soil, water, air, plant and cold-blooded vertebrates. During a fungal survey from mangrove, strains of Scolecobasidium occurring on leaf spots of true mangrove plants, Aegiceras corniculatum and Acanthus ebracteatus, were isolated from Futian Mangrove in Shenzhen and the Qi'ao-Dangan Island Mangrove in Zhuhai, China. Unlike most species in Scolecobasidium that produce dark conidia, our strains are characterized by hyaline to pale brown conidia and inconspicuous thread-like sterigmata. Further detailed morphological comparison and multi-locus (LSU, ITS, tub2, tef1-a) phylogenetic analyses revealed these collections as two new taxa, namely S. acanthi sp. nov. and S. aegiceratis sp. nov. We further emend the generic description of Scolecobasidium, propose one new combination, S. terrestre comb. nov., and clarify the taxonomic status of S. constrictum. [ABSTRACT FROM AUTHOR]

Based on a plain concrete pile composite foundation project in the coastal area of Zhuhai, considering the complex hydraulic load environment induced by tidal water-level changes, finite element simulations and parameter calibrations were carried out to determine the physical and mechanical properties of plain concrete pile composite foundation. The hardening soil small (HSS) model, which can be used to simulate the complex mechanical behavior of soft soil under small strain, was selected for modeling analysis. Model parameters were calibrated through resonance column tests, triaxial consolidation drainage loading and unloading shear tests. The complex hydraulic loads were analyzed, including the effects of cyclic tidal action and the sudden rise and fall of the water level induced by strong storm surges on the force, deformation of plain concrete piles, and the mechanical seepage properties of soft soil around piles. The results indicate that: (1) Compared with coastal soft soil in Shanghai, Zhoushan, Tianjin, and other areas, the soft soil in the Zhuhai area has a smaller dynamic shear modulus, cohesion and internal friction angle, and worse engineering properties. (2) The sudden rise of water level leads to a sudden change in the pore pressure of the groundwater, which induces a large deformation of the pile-soil composite foundation. If the foundation on the offshore (dike) side exhibits the most prominent deformation and foundation damage, such as uneven settlement is prone to occur. (3) The offshore side pile is most affected by the hydraulic loads. The deformation of the pile body along the pile body is uneven and the deformation of the upper pile body is relatively large, which may cause fracture damage. [ABSTRACT FROM AUTHOR]

Recent research has shown the advantages of incorporating multisource geospatial data into the classification of urban functional zones (UFZs), particularly remote sensing and social sensing data. However, the effects of combining datasets of varying quality have not been thoroughly analyzed. In addition, human mobility patterns from social sensing data, which capture signals of human activities, are often represented by origin-destination pairs, thus ignoring spatial relationships between UFZs embedded in mobility trajectories. To address the aforementioned issues, this study proposed a graph-based UFZ classification framework that fuses semantic features from high spatial resolution (HSR) remote sensing images, points of interest, and GPS trajectory data. The framework involves three main steps: (1) High-level scene information in HSR remote sensing imageries was extracted through deep neural networks, and multisource semantic embeddings were constructed based on physical features and social sensing features from multiple geospatial data sources; (2) UFZ mobility graph was constructed by spatially joining trajectory information with UFZs to construct topological connections between functional parcel segments; and (3) UFZ segments and multisource semantic features were transformed into nodes and embeddings in the mobility graphs, and subsequently graph-based models were adopted to identify UFZs. The proposed framework was tested on Zhuhai and Singapore datasets. Results indicated that it outperformed traditional classification methods with an overall accuracy of 76.7% and 84.5% for Zhuhai and Singapore datasets, respectively. The proposed framework contributes to literature in heterogeneous data fusion and is generalizable to other UFZ classification scenarios where human mobility patterns play a role. [ABSTRACT FROM AUTHOR]

The two video satellites of the second and third batch of Zhuhai-1 microsatellites (referred to as OVS-2A/3A) are operational with their hyperspectral satellites, which improves the data acquisi-tion capability of the Zhuhai-1 remote sensing satellite constellation. Contrary to the linear array push-broom hyperspectral satellites and plane array CCD video satellites, the OVS satellite is equipped with a planar array Bayer pattern sensor, which can obtain single-band grayscale images by push-broom imaging. Additionally, the Bayer color reconstruction algorithm can interpolate sensor data to provide RGB color band information. Therefore, for the Bayer pattern push-broom sensor, the relative calibration method of linear push-broom or array cameras cannot be directly applied. The radiometric calibration of the Bayer pattern push-broom imaging mode has become a matter of concern; therefore, this study developed a radiometric calibration method for the Bayer pattern push-broom sensor of the OVS satellite and verified its effectiveness and accuracy. OVS images were used to perform on-orbit relative radiometric calibration, and the calibration accu-racy, including streaking metrics and root-mean-square error, was better than 1%, meeting the specification requirements for the OVS satellite. Visually, after calibration correction, the streaking and striping noise of the Bayer images was removed, and the radiometric quality of the image was considerably improved, providing a good data basis for subsequent research in remote sensing applications. [ABSTRACT FROM AUTHOR]

An extremely heavy rainfall event hit Guangdong province, China, from 27 August to 1 September 2018. There were two different extreme rain regions, respectively, at the Pearl River estuary and eastern Guangdong, and a record-breaking daily precipitation of 1056.7 mm was observed at Gaotan station on 30 August. This paper utilizes a suite of observations from soundings, a gauge network, disdrometers, and polarimetric radars to gain insights to the two rainfall centers. The large-scale meteorological forcing, rainfall patterns, and microphysical processes, as well as radar-based precipitation signatures are investigated. It is concluded that a west-moving monsoon depression played a critical role in sustaining the moisture supply to the two extreme rain regions, and the combined orographic enhancement further contributed to the torrential rainfall over Gaotan station. The raindrop size distributions (DSD) observed at Zhuhai and Huidong stations, as well as the observed polarimetric radar signatures indicate that the rainfall at Doumen region was characterized by larger raindrops but a lower number concentration compared with that at Gaotan region. In addition, the dual-polarization radars are used to quantify precipitation intensity during this extreme event, providing timely information for flood warning and emergency management decision-making. [ABSTRACT FROM AUTHOR]

With increasing urbanization, the compact use of urban land has attracted increasing attention. The mixing degree of urban land use is an important way to realize intensive and efficient land use. In this study, three types of geographic spatiotemporal data, namely, point of interest (POI) data, taxi GPS data, and mobile phone signaling data, were used to identify and analyze the spatiotemporal differentiation characteristics of the functional mixing degree of urban land use in Zhuhai, China. We used correlation and regression analyses to demonstrate the rationality of using the three types of geographic spatiotemporal data in combination to evaluate the degree of functional mixing. We showed that the results obtained using the three types of geographic spatiotemporal data have different emphases, and their combined use can improve the accuracy of research results. On the whole, the functional mixing degree of land use in the study area was generally low and the spatial distribution varied, gradually decreasing away from the center of the old central city in the east of Zhuhai City to the central city in the west of Doumen District. [ABSTRACT FROM AUTHOR]

Based on observation data from the observation tower station in Zhuhai in South China from October 2015 to May 2018, the variations in soil temperature, moisture, and heat flux in the understorey of evergreen broadleaf forest are analyzed. The ground surface temperature is slightly greater than the canopy surface temperature; the soil temperature is the smallest. The seasonal variation in the soil moisture fluctuates around a relative equilibrium as the rain increases or decreases. Both ground and canopy surface temperatures have valley values before sunrise and peak values in the afternoon. The diurnal variations in soil temperature are characterized by a cosine function. With the deepening of the soil layer, the time of valley and peak lag and the amplitude of the variation in the soil temperature decrease. There is almost no diurnal variation in soil temperature at 40 cm depth or the soil heat flux at 30 cm depth. The heat fluxes at depths of 7.5 cm and 15 cm show an "S" pattern variation, with a peak at 17:30. The net radiation of the canopy surface shows a bell-shaped variation, with a peak at 12:30. The averaged soil thermal conductivities are 2.18 W·m−1·K−1, 1.22 W·m−1·K−1, and 1.26 W·m−1·K−1 for 5 ~ 10 cm, 10 ~ 20 cm, and 20 ~ 40 cm depths, respectively. [ABSTRACT FROM AUTHOR]

In view of the near-field seismic action, considering that oblique incidence of seismic waves is more realistic than vertical incidence, the seismic response of the Hong Kong–Zhuhai–Macao immersed tunnel subjected to an obliquely incident SV wave is investigated. Using the finite element method and time-domain wave method, the seismic input is transformed into an equivalent node load with a viscous–spring artificial boundary, and a three-dimensional simulation technology for SV waves of oblique incidence is presented. A half-space numerical example is given to demonstrate the accuracy of the proposed simulation technology. Taking the stress field formed by the self-weight stress and hydrostatic pressure as the initial state of the dynamic response analysis, the static–dynamic coupling numerical simulation of the seismic response of a soil-immersed tunnel system is realized. The results show that the amplification in the vertical and longitudinal response of the tunnel, due to the oblique incidence, reaches maximum when the incident angle is close to the critical angle. Furthermore, the horizontal response and incident angle show the inverse relation and tend to be stable. In addition, the oblique incidence also causes asymmetric shearing in symmetric parts of the tunnel. The root of the shear key easily produces tensile cracks, while the end angle of the shear key is prone to stress concentration and local damage. Thus, the impact of oblique incidence should be considered in the seismic design, and attention should be paid to the optimization of the end angle of the shear key and the configuration of anti-crack reinforcement at the root of shear key to meet the seismic requirements. [ABSTRACT FROM AUTHOR]

Waterlogging disasters cause huge loss of life and property damage every year. In this research, a Copula-based optimization method is proposed to solve the problems in bivariate design of urban stormwater and drainage systems resulting from ignorance of precipitation temporal dependence and discrepancy between different design codes. Optimized design combinations of stormwater and drainage systems conditioned on given Kendall bivariate return periods or return periods of either system can be obtained using the optimization method for the case study of Zhongshan and Zhuhai. Results show that the temporal dependencies between precipitation series with different durations should be carefully considered, which can be sufficiently described by Copula functions. Based on the optimized design combinations, it is found that the planned return periods of stormwater systems in Sponge City Plans are underestimated for both Zhongshan and Zhuhai, which restricts the full use of the drainage systems. According to the optimized results, the planned return periods of stormwater systems in Zhongshan (Zhuhai) should be adjusted to 8.04 a (6.76 a) for the downtown area and 6.52 a (5.59 a) for other areas, conditioned on the planned return periods for P24 h in Sponge City Plans. The proposed optimization method provides a useful approach for the bivariate design of stormwater and drainage systems. The results of this research can give stakeholders references in compiling engineering plans for urban waterlogging prevention and help better balance the conflicts between waterlogging safety and economic efficiency. [ABSTRACT FROM AUTHOR]

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Abstract: Industrial parks are specialized areas that undergo high-intensity economic activities and high-strength resource consumption. Additionally, environmental water carrying capacity is one of the most important supports for sustainable regional development. In this paper, the Fushan Industrial Park in Zhuhai City was selected as a case study, and an integrated evaluation indicator system for environmental water carrying capacity was established according to the environmental and socio-economic status and development plan for this industrial park. The water environmental carrying capacity evaluation model was established according to simulations of socio-economic activity. Our model can forecast the value of assessment indicators to represent their impact degree, which is brought about by socio-economic activities. Next, an entropy indicator assessment method was proposed to analyze the changes in environmental water carrying capacity and to obtain key indicators. The results demonstrate that the industrial park''s development can be supported within the carrying capacity of the current environmental water resources. However, it will exceed the carrying capacity in the future if the industrial park develops without any sustainable regulation or ecological protection, such as water saving technology. [Copyright &y& Elsevier]

A report of the 5th IEEE International Conference on Systems Biology (IEEE ISB2011), 2-4 September 2011, Zhuhai, China [ABSTRACT FROM AUTHOR]

Abstract: The rivers and lakes are not only important parts of the wetland, but the main agricultural irrigation water and important freshwater resources. The changes of the rivers and lakes have heavy effect on the environment and economy. Taking Zhuhai City as the study area, selecting the rivers and lakes as research object, using the Landsat5 TM data in 1995, Landsat7 ETM+data in 2002, CBERS-02B CCD and HR data in 2009 as the main information source, this paper makes an remote sensing interpreation using the combined method of the supervised classification, non-supervised classification, man-computer interactive interpretation and rule-decision classification. Thus, the thematic information of the rivers and lakes are extracted at the three phases in Zhuhai City; then the spatial distribution pattern and dynamic change rules of the rivers and lakes in Zhuhai City are monitored; finally, the driving force of these changes are analyzed. The results show: the area of the rivers increased 6% from 1995 to 2009; but to the lakes, decreased 58%. The increase of the rivers area is because reclamation projects cause the big change of the sea-land position; whereas the decrease of the lakes area is due to the factors such as the warming climate and increasing populaiton. [Copyright &y& Elsevier]

Epoxy asphalt concrete, mortar asphalt concrete and Gussasphalt concrete are commonly used types of deck pavement materials in bridge deck pavement engineering. However, achieving the high-temperature stability and anti-fatigue performance of the deck pavement materials is still challenging. In order to reduce the rutting and cracking risks of the asphalt mixture, this paper proposed pre-coated aggregates grouting asphalt concrete (PGAC) for bridge deck pavement. Laboratory tests were conducted to determine the optimum grouting materials and to evaluate the mechanical performances of the PGAC material. Test results showed that the mechanical properties for PGAC with grouting material of high-viscosity-modified asphalt binder blending with mineral filler were superior to that of GMA-10 used for the Hong Kong-Zhuhai-Macau Bridge deck pavement. Microstructural analysis showed that the PGAC had a more stable skeleton structure compared to other typical aggregate mixtures. This study highlights the performances of the proposed PGAC and sheds light on the deck pavement material improvement of both high-temperature stability and anti-fatigue performance that could be achieved. [ABSTRACT FROM AUTHOR]

Oysters are one of the main aquatic products sold in coastal areas worldwide and are popular among consumers because of their delicious taste and nutritional value. However, the microorganisms present in oysters may pose health risks to consumers. In this study, the microbial communities of Pacific oysters (Crassostrea gigas) collected from aquatic product markets in three cities (Guangzhou, Zhuhai, and Jiangmen) of Guangdong Province, China, where raw oysters are popular, were investigated. The plate counts of viable bacteria in oysters collected in the three cities were all approximately 2 log colony-forming units/g. High-throughput sequencing analysis of the V3–V4 region of the 16Sribosomal DNA gene showed a high level of microbial diversity in oysters, as evidenced by both alpha and beta diversity analysis. Proteobacteria, Bacteroidetes, and Firmicutes were the dominant phyla of the microorganisms present in these samples. A variety of pathogenic bacteria, including the fatal foodborne pathogen Vibrio vulnificus , were found, and Vibrio was the dominant genus. Additionally, the relationship between other microbial species and pathogenic microorganisms may be mostly symbiotic in oysters. These data provide insights into the microbial communities of retail oysters in the Guangdong region and indicate a considerable risk related to the consumption of raw oysters. [ABSTRACT FROM AUTHOR]

Constructing a scientific and quantitative quality-assessment model for farmland is important for understanding farmland quality, and can provide a theoretical basis and technical support for formulating rational and effective management policies and realizing the sustainable use of farmland resources. To more accurately reflect the systematic, complex, and differential characteristics of farmland quality, this study aimed to explore an intelligent farmland quality-assessment method that avoids the subjectivity of determining indicator weights while improving assessment accuracy. Taking Xiangzhou in Hubei Province, China, as the study area, 14 indicators were selected from four dimensions—terrain, soil conditions, socioeconomics, and ecological environment—to build a comprehensive assessment index system for farmland quality applicable to the region. A total of 1590 representative samples in Xiangzhou were selected, of which 1110 were used as training samples, 320 as test samples, and 160 as validation samples. Three models of entropy weight (EW), backpropagation neural network (BPNN), and random forest (RF) were selected for training, and the assessment results of farmland quality were output through simulations to compare their assessment accuracy and analyze the distribution pattern of farmland quality grades in Xiangzhou in 2018. The results showed the following: (1) The RF model for farmland quality assessment required fewer parameters, and could simulate the complex relationships between indicators more accurately and analyze each indicator's contribution to farmland quality scientifically. (2) In terms of the average quality index of farmland, RF > BPNN > EW. The spatial patterns of the quality index from RF and BPNN were similar, and both were significantly different from EW. (3) In terms of the assessment results and precision characterization indicators, the assessment results of RF were more in line with realities of natural and socioeconomic development, with higher applicability and reliability. (4) Compared to BPNN and EW, RF had a higher data mining ability and training accuracy, and its assessment result was the best. The coefficient of determination (R2) was 0.8145, the mean absolute error (MAE) was 0.009, and the mean squared error (MSE) was 0.012. (5) The overall quality of farmland in Xiangzhou was higher, with a larger area of second- and third-grade farmland, accounting for 54.63%, and the grade basically conformed to the trend of positive distribution, showing an obvious pattern of geographical distribution, with overall high performance in the north-central part and low in the south. The distribution of farmland quality grades also varied widely among regions. This showed that RF was more suitable for the quality assessment of farmland with complex nonlinear characteristics. This study enriches and improves the index system and methodological research of farmland quality assessment at the county scale, and provides a basis for achieving a threefold production pattern of farmland quantity, quality, and ecology in Xiangzhou, while also serving as a reference for similar regions and countries. [ABSTRACT FROM AUTHOR]

The possibility of quantitative inversion of salinized soil moisture content (SMC) from Zhuhai-1 hyperspectral imagery and the application effect of fractional order differentially optimized spectral indices were discussed, which provided new research ideas for improving the accuracy of hyperspectral remote sensing inversion. The hyperspectral data from indoor and Zhuhai-1 remote sensing imagery were resampled to the same spectral scale. The soil hyperspectral data were processed by fractional order differential preprocessing method and optimized spectral indices method, and the Pearson correlation coefficient (PCC/r) analysis was made with SMC data. The sensitive optimized spectral indices were used to establish the ground hyperspectral estimation model, and a variety of modeling methods were used to select the best SMC inversion model. The results were as follows: the maximum one-dimensional r between SMC and the 466–938 nm band was −0.635, the maximum one-dimensional r with the 0.5-order absorbance spectrum was 0.665, and the maximum two-dimensional r with the difference index (DI) calculated by the 0.5-order absorbance spectrum was ±0.72. The maximum three-dimensional r with the triangle vegetation index (TVI) calculated from the 0.5-order absorbance spectrum reached 0.755, which exceeded the one-dimensional r extreme value of 400–2400 nm. The TreeNet gradient boosting machine (TGBM) regression model had the highest modeling accuracy, with a calibration coefficient of determination (R2C) = 0.887, calibration root mean square error (RMSEC) = 2.488%, standard deviation (SD) = 6.733%, and r = 0.942. However, the partial least squares regression (PLSR) model had the strongest predictive ability, with validation coefficient of determination (R2V) = 0.787, validation root mean square error (RMSEV) = 3.247%, and relative prediction deviation (RPD) = 2.071. The variable importance in projection (VIP) method could not only improve model efficiency but also increased model accuracy. R2C of the optimal PLSR model was 0.733, RMSEC was 3.028%, R2V was 0.805, RMSEV was 3.100%, RPD was 1.976, and Akaike information criterion (AIC) was 151.050. The three-band optimized spectral indices with fractional differential pretreatment could to a certain extent break through the limitation of visible near-infrared spectrum in SMC estimation due to the lack of shortwave infrared spectra, which made it possible to quantitatively retrieve saline SMC on the basis of Zhuhai-1 hyperspectral imagery. [ABSTRACT FROM AUTHOR]

Zhang, X., 2020. Position enhancement and development strategies of Zhuhai's economy in Guangdong-Hong Kong-Macao Greater bay area. In: Al-Tarawneh, O. and Megahed, A. (eds.), Recent Developments of Port, Marine, and Ocean Engineering. Journal of Coastal Research, Special Issue No. 110, pp. 201–205. Coconut Creek (Florida), ISSN 0749-0208. The economic circle of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) has an important impact on China's economic development and surrounding economic cooperation. Zhuhai plays a non-negligible position in the economic construction of the GBA. To build the GBA into a global advanced economic center, it's important to promote Zhuhai's economic position in the GBA. For this, the authors attempt to systematically study the position enhancement and development strategies of Zhuhai in the GBA. First the position of GBA in the global integrated economy was analyzed. Then, it discusses about the economic development trend of Zhuhai, and proposes corresponding economic development countermeasures and industrial structure optimization methods. The study found that compared with other cities in the GBA, Zhuhai has a relatively higher economic growth rate, a better investment environment, and greater potentials for development; the proportions of the secondary and tertiary industries in Zhuhai are almost the same; to maintain long-term economic development, Zhuhai needs to increase the proportion of the primary industry and optimize the industrial structure. The research findings provide a theoretical basis for Zhuhai's economic development and position enhancement in the GBA. [ABSTRACT FROM AUTHOR]