Marine sediments collected from the Zhujiang(Pearl) River Estuary(ZRE) and South China Sea(SCS) were utilized to study the occurrence and spatial distribution of tetrabromobisphenol A(TBBPA) and hexabromocyclododecane...Marine sediments collected from the Zhujiang(Pearl) River Estuary(ZRE) and South China Sea(SCS) were utilized to study the occurrence and spatial distribution of tetrabromobisphenol A(TBBPA) and hexabromocyclododecane(HBCDD).The levels of TBBPA and HBCDD in sediments ranged from not detected(nd) to 6.14 ng/g dry weight(dw) and nd to 0.42 ng/g dw.TBBPA concentrations in marine sediments were substantially higher than HBCDD.The concentrations of TBBPA and HBCDD in the ZRE sediments were significantly greater than those in the SCS.α-HBCDD(48.7%) and γ-HBCDD(46.2%) were the two main diastereoisomers of HBCDD in sediments from the ZRE,with minor contribution of β-HBCDD(5.1%).HBCDD were only found in one sample from the northern SCS.The enantiomeric fraction of α-HBCDD in sediments from the ZRE was obviously greater than 0.5,indicating an accumulation of(+)-α-HBCDD.The enantiomers of HBCDD were not measured in sediments from the SCS.This work highlighted the environmental behaviors of TBBPA and HBCDD in marine sediments.展开更多
Pearl millet(Pennisetum glaucum)is one of the major millets with high nutritional properties.This crop exhibits exceptional resilience to drought and high temperatures.However,the processing of pearl millet poses a si...Pearl millet(Pennisetum glaucum)is one of the major millets with high nutritional properties.This crop exhibits exceptional resilience to drought and high temperatures.However,the processing of pearl millet poses a significant challenge due to its high lipid content,enzyme activity,and presence of antinutrients.Consequently,it becomes imperative to enhance the quality and prolong the shelf life of pearl millet flour by employing suitable technologies.Hydrothermal treatment in the food industry has long been seen as promising due to its potential to reduce microbial load,inactivate enzymes,and improve nutrient retention.This study aims to investigate the effects of hydrothermal treatment on the quality characteristics of pearl millet.The independent variables of the study were soaking temperature(35,45,55℃),soaking time(2,3,4 h),and steaming time(5,10,15 min).Treatment conditions had a statistically significant effect on nutrient retention.Major antinutrients like tannins and phytates were reduced by 0.99% to 5.94% and 0.36% to 6.00%,respectively,after the treatment.Lipase activity decreased significantly up to 10% with the treatment conditions.The findings of this study could potentially encourage the use of pearl millet flour in the production of various food items and promote the application of hydrothermal treatment in the field of food processing.展开更多
Based on the practice of oil and gas exploration in the Huizhou Sag of the Pearl River Mouth Basin,the geochemical indexes of source rocks were measured,the reservoir development morphology was restored,the rocks and ...Based on the practice of oil and gas exploration in the Huizhou Sag of the Pearl River Mouth Basin,the geochemical indexes of source rocks were measured,the reservoir development morphology was restored,the rocks and minerals were characterized microscopically,the measured trap sealing indexes were compared,the biomarker compounds of crude oil were extracted,the genesis of condensate gas was identified,and the reservoir-forming conditions were examined.On this basis,the Paleogene Enping Formation in the Huizhou 26 subsag was systematically analyzed for the potential of oil and gas resources,the development characteristics of large-scale high-quality conglomerate reservoirs,the trapping effectiveness of faults,the hydrocarbon migration and accumulation model,and the formation conditions and exploration targets of large-and medium-sized glutenite-rich oil and gas fields.The research results were obtained in four aspects.First,the Paleogene Wenchang Formation in the Huizhou 26 subsag develops extensive and thick high-quality source rocks of semi-deep to deep lacustrine subfacies,which have typical hydrocarbon expulsion characteristics of"great oil generation in the early stage and huge gas expulsion in the late stage",providing a sufficient material basis for hydrocarbon accumulation in the Enping Formation.Second,under the joint control of the steep slope zone and transition zone of the fault within the sag,the large-scale near-source glutenite reservoirs are highly heterogeneous,with the development scale dominated hierarchically by three factors(favorable facies zone,particle component,and microfracture).The(subaqueous)distributary channels near the fault system,with equal grains,a low mud content(<5%),and a high content of feldspar composition,are conducive to the development of sweet spot reservoirs.Third,the strike-slip pressurization trap covered by stable lake flooding mudstone is a necessary condition for oil and gas preservation,and the NE and nearly EW faults obliquely to the principal stress have the best control on traps.Fourth,the spatiotemporal configuration of high-quality source rocks,fault transport/sealing,and glutenite reservoirs controls the degree of hydrocarbon enrichment.From top to bottom,three hydrocarbon accumulation units,i.e.low-fill zone,transition zone,and high-fill zone,are recognized.The main area of the channel in the nearly pressurized source-connecting fault zone is favorable for large-scale hydrocarbon enrichment.The research results suggest a new direction for the exploration of large-scale glutenite-rich reservoirs in the Enping Formation of the Pearl River Mouth Basin,and present a major breakthrough in oil and gas exploration.展开更多
China’s low-carbon development path will make significant contributions to achieving global sustainable development goals.Due to the diverse natural and economic conditions across different regions in China,there exi...China’s low-carbon development path will make significant contributions to achieving global sustainable development goals.Due to the diverse natural and economic conditions across different regions in China,there exists an imbalance in the distribution of car-bon emissions.Therefore,regional cooperation serves as an effective means to attain low-carbon development.This study examined the pattern of carbon emissions and proposed a potential joint emission reduction strategy by utilizing the industrial carbon emission intens-ity(ICEI)as a crucial factor.We utilized social network analysis and Local Indicators of Spatial Association(LISA)space-time trans-ition matrix to investigate the spatiotemporal connections and discrepancies of ICEI in the cities of the Pearl River Basin(PRB),China from 2010 to 2020.The primary drivers of the ICEI were determined through geographical detectors and multi-scale geographically weighted regression.The results were as follows:1)the overall ICEI in the Pearl River Basin is showing a downward trend,and there is a significant spatial imbalance.2)There are numerous network connections between cities regarding the ICEI,but the network structure is relatively fragile and unstable.3)Economically developed cities such as Guangzhou,Foshan,and Dongguan are in the center of the network while playing an intermediary role.4)Energy consumption,industrialization,per capita GDP,urbanization,science and techno-logy,and productivity are found to be the most influential variables in the spatial differentiation of ICEI,and their combination in-creased the explanatory power of the geographic variation of ICEI.Finally,through the analysis of differences and connections in urban carbon emissions under different economic levels and ICEI,the study suggests joint carbon reduction strategies,which are centered on carbon transfer,financial support,and technological assistance among cities.展开更多
A transfer zone in rift basins preserves important information on regional tectonic evolution and plays significant roles in hydrocarbon accumulation.Based on the systematic analysis of 3D seismic data and hydrocarbon...A transfer zone in rift basins preserves important information on regional tectonic evolution and plays significant roles in hydrocarbon accumulation.Based on the systematic analysis of 3D seismic data and hydrocarbon accumulation conditions,the geometry,kinematics,and reservoir control of a large synthetic overlapping transfer zone in the south of the Wenchang A subsag in the Zhujiang(Pearl)River Mouth basin were investigated.Results indicate that the development and evolution of the transfer zone was controlled by the interaction between pre-existing faults and regional stress transformation.The intense rifting of the main faults of the transfer zone controlled the development of source rocks and faultcontrolled slope break paleogeomorphology.The strike-slip overprint since the Oligocene is conducive to the formation of a large-scale fault-anticline trap,and the secondary faults in the transfer zone contribute to the hydrocarbon transportation.The conjugate intersection area of the NE-and NW-trending faults offers more opportunity for hydrocarbon migration and accumulation.展开更多
The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high...The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high-resolution 3D seismic,logging and core data of Pearl River Mouth Basin(PRMB),this paper dissected the shelf-edge delta to deep-water fan(SEDDF)depositional system in the Oligocene Zhuhai Formation of Paleogene in south subsag of Baiyun Sag,and revealed the complex coupling relationship from the continental shelf edge to deep-water fan sedimentation and its genetic mechanisms.The results show that during the deposition of the fourth to first members of the Zhuhai Formation,the scale of the SEDDF depositional system in the study area showed a pattern of first increasing and then decreasing,with deep-water fan developed in the third to first members and the largest plane distribution scale developed in the late stage of the second member.Based on the development of SEDDF depositional system along the source direction,three types of coupling relationships are divided,namely,deltas that are linked downdip to fans,deltas that lack downdip fans and fans that lack updip coeval deltas,with different depositional characteristics and genetic mechanisms.(1)Deltas that are linked downdip to fans:with the development of shelf-edge deltas in the shelf area and deep-water fans in the downdip slope area,and the strong source supply and relative sea level decline are the two key factors which control the development of this type of source-to-sink(S2S).The development of channels on the continental shelf edge is conducive to the formation of this type of S2S system even with weak source supply and high sea level.(2)Deltas that lack downdip fans:with the development of shelf edge deltas in shelf area,while deep water fans are not developed in the downdip slope area.The lack of“sources”and“channels”,and fluid transformation are the three main reasons for the formation of this type of S2S system.(3)Fans that lack updip coeval deltas:with the development of deep-water fans in continental slope area and the absence of updip coeval shelf edge deltas,which is jointly controlled by the coupling of fluid transformation at the shelf edge and the“channels”in the continental slope area.展开更多
Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift ...Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift normal fault through detailed seismic interpretation and fault modeling.A total of 289 post-rift normal faults were identified in the study area and can be classified into four types:(1)isolated normal faults above the carbonate platform;(2)isolated normal faults cutting through the carbonate platform;(3)conjugate normal faults,and(4)connecting normal faults.Throw distribution analysis on the fault planes show that the vertical throw profiles of most normal fault exhibit flat-topped profiles.Isolated normal faults above the carbonate platform exhibit roughly concentric ellipses with maximum throw zones in the central section whereas the normal faults cutting through the carbonate platform miss the lowermost section due to the chaotic seismic reflections in the interior of the carbonate platform.The vertical throws of conjugate normal faults anomalously decrease toward their intersection region on the fault plane whereas the connecting normal faults present two maximum throw zones in the central section of the fault plane.According to the symmetric elliptical distribution model of fault throw,an estimation was made indicating that normal faults cutting through the carbonate platform extended downward between-1308 s and-1780 s(two-way travel time)in depth and may not penetrate the entire Liuhua carbonate platform.Moreover,it is observed that the distribution of karst caves on the top of the carbonate platform disaccord with those of hydrocarbon reservoirs and the post-rift normal faults cutting through the carbonate platform in the study area.We propose that these karst caves formed most probably by corrosive fluids derived from magmatic activities during the Dongsha event,rather than pore waters or hydrocarbons.展开更多
THIRTY-FOUR years ago,the tallest building in Shanghai’s Pudong area was the Fire Watchtower on Dongchang Road.Its height was merely 24 meters.It was matched by Pudong’s GDP,which was a little over RMB six billion.T...THIRTY-FOUR years ago,the tallest building in Shanghai’s Pudong area was the Fire Watchtower on Dongchang Road.Its height was merely 24 meters.It was matched by Pudong’s GDP,which was a little over RMB six billion.Today,the tallest building in Pudong is the Shanghai Tower at a whopping height of 632 meters,and the skyline is full of majestic skyscrapers,such as the Oriental Pearl Tower and Shanghai World Financial Center.Proportionately,the district’s GDP has rocketed to over RMB 1.67 trillion.Reform and opening-up,started in 1978,has brought new vitality and prosperity,along with dramatic changes.展开更多
Container ports and hinterland manufacturing are two important forces of the local participation in economic globalization.This study,taking the Pearl River Delta(PRD),China with an export-oriented economy as an examp...Container ports and hinterland manufacturing are two important forces of the local participation in economic globalization.This study,taking the Pearl River Delta(PRD),China with an export-oriented economy as an example,applies Huff and panel regres-sion models to evaluate the impact of hinterland manufacturing on the development of container ports during the period of 1993–2019.The results show that 1)the spatial patterns of hinterlands for hub ports help to determine the distribution range and scale of economic variables that affect port throughput;2)the hinterland’s gross manufacturing output has universally positive influence on port through-put,wherein export-oriented processing and the entire manufacturing industry have significantly positive impact on port throughput in 1993–2011 and 2001–2019,respectively;3)the two internal structural factors related to an export-oriented economy,labor-intensive sectors and foreign-funded terminals,have positively moderate the direct influence of hinterland manufacturing on port throughput.Our results highlight the importance of local context in understanding port-manufacturing relationship in developing economies.Based on our findings,policy implications are further proposed to enhance port network organization in PRD.展开更多
Urban night tourism is a new form of urban tourism development and an important driving force for the prosperity of urban night economy.As the most prestigious business card among many night tour projects in Guangzhou...Urban night tourism is a new form of urban tourism development and an important driving force for the prosperity of urban night economy.As the most prestigious business card among many night tour projects in Guangzhou,the Pearl River water night tour has contributed to the development of Guangzhou s night economy,which cannot be underestimated.However,in the process of rapid development,there are also problems such as diversified operators,insufficient integration of intangible cultural elements,excessive commercial attributes,issues of tourism facilities and service facilities.Under the new stage of integrated development of culture and tourism,how to use mutual promotion of culture and tourism in the Pearl River night tour to seek innovative paths for high-quality development in the future is the main problem expected to be solved in this paper.Therefore,based on the perspective of culture and tourism integration,this paper analyzes the general situation and development status of the Pearl River night tour,and proposes five development strategies:the overall planning of culture and tourism integration,the deep integration of intangible cultural elements,the balance of commercial attributes and tourism attributes,the high integration of culture,business,tourism and education,and the creation of tourism atmosphere,in order to provide inspiration for the healthy,orderly and high-quality development of the Pearl River night tour.展开更多
Shanghai,a metropolis in east China that is leading the development of the Yangtze River Delta region is emerging as a powerhouse in the growth of new quality productive forces.Developing new quality productive forces...Shanghai,a metropolis in east China that is leading the development of the Yangtze River Delta region is emerging as a powerhouse in the growth of new quality productive forces.Developing new quality productive forces has been listed as one of the important goals for the government in 2024.展开更多
Background: Early marriage is prevalent in Middle Eastern culture. The objective of this study was to investigate the pregnancy outcomes of married pregnant adolescents in a prosperous and highly developed Middle East...Background: Early marriage is prevalent in Middle Eastern culture. The objective of this study was to investigate the pregnancy outcomes of married pregnant adolescents in a prosperous and highly developed Middle Eastern society, when they receive sufficient prenatal care and social assistance. Methods: A retrospective analysis was performed on the Peristat-based Maternal-Newborn registry utilizing hospital data acquired from four main governmental hospitals in Qatar. The study analyzed the pregnancy outcomes of young adults [ages 20 - 24) who experienced their first pregnancy and compared them to the pregnancy outcomes of adolescents aged 15 to 19 years old. Results: The study comprised a cohort of 3152 pregnant married women. This cohort included 2674 women between the ages of 20 and 24, as well as 478 adolescents aged 15 to 19 years old. In comparison to the young adult group, the non-Qatari population in the adolescent group was significantly higher (78.6% (376/478) vs. 71.5% (1914/2674), p-value = 0.003). Other Arab nationalities accounted for more than half of the adolescent population. All the mothers were married, did not use alcohol, and were nonsmokers. There were no documented mothers under the age of 15. Attending antenatal clinics was significantly higher in the adolescent group (p < 0.001). There was no significant difference in the mean gestational age at birth between adolescents and young adults (38.5 ± 2.3 weeks vs. 38.7 ± 2.1 weeks, p = 0.06). Furthermore, adolescent mothers had a higher rate of low birth weight (13.6% vs. 10.4%, p < 0.001) than young mothers. There was a non-statistically significant rise in pre-eclampsia incidence. Other unfavorable pregnancy outcomes were less common among them, such as diabetes, operative vaginal delivery, caesarean section, stillbirth, NICU hospitalization, and an Apgar score of less than 7 at five minutes. There were no maternal deaths;however, there was a comparable rate of neonatal in-hospital mortality. Conclusion: Pregnancy during adolescence may not relate to significant problems in a well-tolerant culture that ensures dedicated antenatal and social support.展开更多
Real-time observations in the field and numerical simulations（with Delft3D） were combined to study the formation, distribution and the relevant influencing factors of turbidity maximum（TM） in the Zhujiang（Pearl R...Real-time observations in the field and numerical simulations（with Delft3D） were combined to study the formation, distribution and the relevant influencing factors of turbidity maximum（TM） in the Zhujiang（Pearl River） Estuary（ZE）. The spatial distribution pattern of the TM varies with the longitudinal distributions of salinity and suspended sediment concentration（SSC）. The SSC is enhanced and the TM is intensified during dry seasons,whereas the center of the TM moves upstream by a distance of 10 km during wet seasons. The formation of the TM is influenced by a complex combination of numerous factors, including tides, river discharges and topography, wherein sediment resuspension and vertical circulation dominate the formations and variability of the TM.展开更多
The distributions of estuarine colored dissolved organic matter（CDOM）are the combined results of physicalbiogeochemical processes.Remote sensing is needed to monitor highly dynamically estuarine CDOM.Using in situ d...The distributions of estuarine colored dissolved organic matter（CDOM）are the combined results of physicalbiogeochemical processes.Remote sensing is needed to monitor highly dynamically estuarine CDOM.Using in situ data from four seasonal cruises,an algorithm is developed to estimate CDOM absorption coefficient at 400nm（aCDOM（400））in the Zhujiang（Pearl River）Estuary（ZJE）.The algorithm uses band ratios of Rrs（667）/Rrs（443）and Rrs（748）/Rrs（412）.By applying it to moderate resolution imaging spectroradiometer onboard Aqua satellite（MODIS/Aqua）data from 2002 to 2014,seasonal climatology aCDOM（400）in the ZJE is calculated.CDOM distributions are majorly influenced by water discharge from the Zhujiang River and underwater topography.Along the section vertical to a water depth gradient,the seasonal aCDOM（400）exponentially decreased（y=aebx,b〈0）,but with great differences among seasons.Riverine fresh water is the primary source of CDOM in the ZJE.Fulvic acid fraction decreases with increasing salinity.Using developed algorithms,conservative CDOM mixing equation,and river discharge,effective riverine end-member concentration and flux of dissolved organic carbon（DOC）in summer and winter from 2002 to 2014 are first estimated from the MODIS/Aqua data.Both effective riverine end-member DOC concentration and flux are positively related to the river discharge,significantly in summer with R-2 of 0.698 for concentration and 0.965 7 for flux.展开更多
The Yangjiang-Yitongdong Fault (YJF) is an important NW-trending regional fault, which divides the Zhujiang (Pearl) River Mouth Basin (ZRMB) into western and eastern segments. In Cenozoic, the northern continental mar...The Yangjiang-Yitongdong Fault (YJF) is an important NW-trending regional fault, which divides the Zhujiang (Pearl) River Mouth Basin (ZRMB) into western and eastern segments. In Cenozoic, the northern continental margin of the South China Sea (SCS) underwent continental rifting, breakup, seafloor spreading and thermal subsidence processes, and the Cenozoic activities of YJF is one part of this series of complex processes. Two long NW-trending multichannel seismic profiles located on both sides of the YJF extending from the continental shelf to Continent-Ocean Boundary (COB) were used to study the tectonic and sedimentary characteristics of western ZRMB. Using the 2D-Move software and back-stripping method, we constructed the balance cross-section model and calculated the fault activity rate. Through the comprehensive consideration of tectonic position, tectonic evolution history, featured structure, and stress analysis, we deduced the activity history of the YJF in Cenozoic. The results showed that the YJF can be divided into two segments by the central uplift belt. From 65 Ma to 32 Ma, the YJF was in sinistral motion as a whole, inherited the preexisting sinistral motion of Mesozoic YJF, in which, the southern part of YJF was mainly in extension activity, controlling the formation and evolution of Yunkai Low Uplift, coupled with slight sinistral motion. From 32 Ma to 23.8 Ma, the sinistral motion in northern part of YJF continued, while the sinistral motion in southern part began to stop or shifted to a slightly dextral motion. After 23.8 Ma, the dextral motion in southern part of YJF continued, while the sinistral motion in northern part of YJF gradually stopped, or shifted to the slightly dextral motion. The shift of the YJF strike-slip direction may be related to the magmatic underplating in continent-ocean transition, southeastern ZRMB. According to the analysis of tectonic activity intensity and rift sedimentary structure, the activities of YJF in Cenozoic played a regulating role in the rift extension process of ZRMB.展开更多
In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. ...In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. The traditional gravity model assumes ideal conditions, but these preconditions and their results often do not exist in realistic conditions. Thus, we used a modified gravity model to characterize the city contacts within a specific region. This model considers factors such as intercity complementarities, government intervention, and the diversity of the transportation infrastructure which is characterized as the transportation distance instead of the traditional Euclidean distance. We applied this model to an empirical study of city contact in the Zhujiang(Pearl) River Delta(PRD) of China. The regression results indicated that the modified gravity model could measure city contact more accurately and comprehensively than the traditional gravity model, i.e., it yielded a higher adjusted R2 value(0.379) than the traditional gravity model result(0.259). Our study also suggests that, in addition to urban-regional and metropolitan development, the complementarities of the basic functions of cities at the administrative and market levels, as well as the corporeal and immaterial levels, play very significant roles in the characterization of city contact. Given the complexity of city contact, it will be necessary to consider more relevant influential factors in the modified gravity model to characterize the features of city contact in the future.展开更多
Chemometric approach based on principal component analysis（PCA） was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River（Pearl River） Estuary and adjacent...Chemometric approach based on principal component analysis（PCA） was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River（Pearl River） Estuary and adjacent waters（ZREAW） in the South China Sea. The PCA result shows that the ZREAW can be divided into different zones according to the principal components and geographical locations of the study stations,and indicates that there are distinct regional variances on environmental features and the corresponding phytoplankton biomass and community structures among different areas. The spatial distribution of ecological features was implied to be influenced by various degrees of the different water resources,such as the Pearl River discharges,the coastal current and the oceanic water from the South China Sea. The variation of the biomass maximum zone and the complex impacts on the spatial distributions of phytoplankton biomass and production were also evaluated.展开更多
Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is us...Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is used to adaptively decompose the sea level time series in order to extract the secular trend component. Then the linear relationship between the global mean sea level （GMSL） change and the Zhujiang （Pearl） River Delta （PRD） sea level change is calculated： an increase of 1.0 m in the GMSL corresponds to a 1.3 m （uncertainty interval from 1.25 to 1.46 m） increase in the PRD. Based on this relationship and the GMSL rise projected by the Coupled Model Intercomparison Project Phase 5 under three greenhouse gas emission scenarios （representative concentration pathways, or RCPs, from low to high emission scenarios RCP2.6, RCP4.5, and RCP8.5）, the PRD sea level is calculated and projected for the period 2006-2100. By around the year 2050, the PRD sea level will rise 0.29 （0.21 to 0.40） m under RCP2.6, 0.31 （0.22 to 0.42） m under RCP4.5, and 0.34 （0.25 to 0.46） m under RCP8.5, respectively. By 2100, it will rise 0.59 （0.36 to 0.88） m, 0.71 （0.47 to 1.02） m, and 1.0 （0.68 to 1.41） m, respectively. In addition, considering the extreme value of relative sea level due to land subsidence （i.e., 0.20 m） and that obtained from intermonthly variability （i.e., 0.33 m）, the PRD sea level will rise 1.94 m by the year 2100 under the RCP8.5 scenario with the upper uncertainty level （i.e., 1.41 m）. Accordingly, the potential submerged area is 8.57x103 km2 for the PRD, about 1.3 times its present area.展开更多
Although remote sensing data have been used to estimate total suspended matter （TSM） in coastal waters, it has limitations when applied to estuary waters in low spatial resolution situations. The spatial resolution ...Although remote sensing data have been used to estimate total suspended matter （TSM） in coastal waters, it has limitations when applied to estuary waters in low spatial resolution situations. The spatial resolution of ocean color satellites such as SeaWiFS and MODIS is usually -1 km, and therefore is not adequate for small, local-scale areas such as the Zhujiang （Pearl） River estuary. In contrast, 30 m-resolution EO-1 Hyperion imagery has potential for studying TSM in localized areas. We measured the surface spectral radiance reflectance of the river estuary water in the visible and near infra-red spectral range. Sensitivity analysis indicated that the ratio of remote sensing reflectance at 813 nm （Rrs（813）） to reflectance at 559 nm （Rrs（559）） could be used to estimate TSM concentration, and a linear relationship was established between the ratio and in-situ TSM concentration. We applied the linear relationship to Hyperion imagery to map TSM concentration in the estuary. The Hyperion imagery provided sufficient spatial resolution to detect spatiotemporal changes in TSM concentrations in the estuary small estuary area. This study demonstrated the usefulness of Hyperion imagery for mapping the distribution of TSM in estuary waters. Keyword： Hyperion; total suspended matter （TSM）; Zhujiang （Pearl） River estuary展开更多
Eleven lithofacies and five lithofacies associations were indentified in the Miocene Zhujiang Formation on the basis of detailed core analysis. It could he determined that three depositional types developed, namely su...Eleven lithofacies and five lithofacies associations were indentified in the Miocene Zhujiang Formation on the basis of detailed core analysis. It could he determined that three depositional types developed, namely submarine fan, basin and deep-water traction current. Six microfacies were further recognized within the fan, including main channels in the inner fan, distributary channels in the middle fan, inter-channels, levees and the outer fan. The lower Zhujiang Formation, mainly sandstone associations, was inner fan and inner-middle fan deposits of the basin fan and the slope fan. The middle part, mainly mudstone associations, was outer fan deposits. With the transgression, the submarine fan was finally replaced by the basinal pelagic deposits which were dominated by mudstone associations, siltstone associations, and deep-water limestone associations. During the weak gravity flow activity, the lower channels, the middle-upper outer fans and basin deposits were strongly modified by the deep-water traction current. The identification of the deep-water traction deposition in Miocene Zhujiang Formation would be of great importance. It could be inferred that the deep- water traction current had been existing after the shelf-break formation since the Late Oligocene （23.8 Ma） in the Baiyun sag, influencing and controlling the sediment composition, the distribution, and depositional processes. It would provide great enlightenment to the paleo-oceanic current circulation in the northern South China Sea.展开更多
基金The Guangdong Basic and Applied Basic Research Foundation under contract Nos 2021B1515020040 and 2021A1515011526the National Natural Science Foundation of China under contract Nos 42277246 and U2244221+1 种基金the Hainan Provincial Natural Science Foundation of China under contract No.422CXTD533the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) under contract No.2019BT02H594。
文摘Marine sediments collected from the Zhujiang(Pearl) River Estuary(ZRE) and South China Sea(SCS) were utilized to study the occurrence and spatial distribution of tetrabromobisphenol A(TBBPA) and hexabromocyclododecane(HBCDD).The levels of TBBPA and HBCDD in sediments ranged from not detected(nd) to 6.14 ng/g dry weight(dw) and nd to 0.42 ng/g dw.TBBPA concentrations in marine sediments were substantially higher than HBCDD.The concentrations of TBBPA and HBCDD in the ZRE sediments were significantly greater than those in the SCS.α-HBCDD(48.7%) and γ-HBCDD(46.2%) were the two main diastereoisomers of HBCDD in sediments from the ZRE,with minor contribution of β-HBCDD(5.1%).HBCDD were only found in one sample from the northern SCS.The enantiomeric fraction of α-HBCDD in sediments from the ZRE was obviously greater than 0.5,indicating an accumulation of(+)-α-HBCDD.The enantiomers of HBCDD were not measured in sediments from the SCS.This work highlighted the environmental behaviors of TBBPA and HBCDD in marine sediments.
基金the Ministry of Human Resource Development,Govt.of India,for providing scholarship grants to the authors.
文摘Pearl millet(Pennisetum glaucum)is one of the major millets with high nutritional properties.This crop exhibits exceptional resilience to drought and high temperatures.However,the processing of pearl millet poses a significant challenge due to its high lipid content,enzyme activity,and presence of antinutrients.Consequently,it becomes imperative to enhance the quality and prolong the shelf life of pearl millet flour by employing suitable technologies.Hydrothermal treatment in the food industry has long been seen as promising due to its potential to reduce microbial load,inactivate enzymes,and improve nutrient retention.This study aims to investigate the effects of hydrothermal treatment on the quality characteristics of pearl millet.The independent variables of the study were soaking temperature(35,45,55℃),soaking time(2,3,4 h),and steaming time(5,10,15 min).Treatment conditions had a statistically significant effect on nutrient retention.Major antinutrients like tannins and phytates were reduced by 0.99% to 5.94% and 0.36% to 6.00%,respectively,after the treatment.Lipase activity decreased significantly up to 10% with the treatment conditions.The findings of this study could potentially encourage the use of pearl millet flour in the production of various food items and promote the application of hydrothermal treatment in the field of food processing.
基金Supported by the CNOOC Major Technology Project During the 14th FIVE-YEAR PLAN PERIOD(KJGG2022-0403)CNOOC Major Technology Project(KJZH-2021-0003-00).
文摘Based on the practice of oil and gas exploration in the Huizhou Sag of the Pearl River Mouth Basin,the geochemical indexes of source rocks were measured,the reservoir development morphology was restored,the rocks and minerals were characterized microscopically,the measured trap sealing indexes were compared,the biomarker compounds of crude oil were extracted,the genesis of condensate gas was identified,and the reservoir-forming conditions were examined.On this basis,the Paleogene Enping Formation in the Huizhou 26 subsag was systematically analyzed for the potential of oil and gas resources,the development characteristics of large-scale high-quality conglomerate reservoirs,the trapping effectiveness of faults,the hydrocarbon migration and accumulation model,and the formation conditions and exploration targets of large-and medium-sized glutenite-rich oil and gas fields.The research results were obtained in four aspects.First,the Paleogene Wenchang Formation in the Huizhou 26 subsag develops extensive and thick high-quality source rocks of semi-deep to deep lacustrine subfacies,which have typical hydrocarbon expulsion characteristics of"great oil generation in the early stage and huge gas expulsion in the late stage",providing a sufficient material basis for hydrocarbon accumulation in the Enping Formation.Second,under the joint control of the steep slope zone and transition zone of the fault within the sag,the large-scale near-source glutenite reservoirs are highly heterogeneous,with the development scale dominated hierarchically by three factors(favorable facies zone,particle component,and microfracture).The(subaqueous)distributary channels near the fault system,with equal grains,a low mud content(<5%),and a high content of feldspar composition,are conducive to the development of sweet spot reservoirs.Third,the strike-slip pressurization trap covered by stable lake flooding mudstone is a necessary condition for oil and gas preservation,and the NE and nearly EW faults obliquely to the principal stress have the best control on traps.Fourth,the spatiotemporal configuration of high-quality source rocks,fault transport/sealing,and glutenite reservoirs controls the degree of hydrocarbon enrichment.From top to bottom,three hydrocarbon accumulation units,i.e.low-fill zone,transition zone,and high-fill zone,are recognized.The main area of the channel in the nearly pressurized source-connecting fault zone is favorable for large-scale hydrocarbon enrichment.The research results suggest a new direction for the exploration of large-scale glutenite-rich reservoirs in the Enping Formation of the Pearl River Mouth Basin,and present a major breakthrough in oil and gas exploration.
基金Under the auspices of the Philosophy and Social Science Planning Project of Guizhou,China(No.21GZZD59)。
文摘China’s low-carbon development path will make significant contributions to achieving global sustainable development goals.Due to the diverse natural and economic conditions across different regions in China,there exists an imbalance in the distribution of car-bon emissions.Therefore,regional cooperation serves as an effective means to attain low-carbon development.This study examined the pattern of carbon emissions and proposed a potential joint emission reduction strategy by utilizing the industrial carbon emission intens-ity(ICEI)as a crucial factor.We utilized social network analysis and Local Indicators of Spatial Association(LISA)space-time trans-ition matrix to investigate the spatiotemporal connections and discrepancies of ICEI in the cities of the Pearl River Basin(PRB),China from 2010 to 2020.The primary drivers of the ICEI were determined through geographical detectors and multi-scale geographically weighted regression.The results were as follows:1)the overall ICEI in the Pearl River Basin is showing a downward trend,and there is a significant spatial imbalance.2)There are numerous network connections between cities regarding the ICEI,but the network structure is relatively fragile and unstable.3)Economically developed cities such as Guangzhou,Foshan,and Dongguan are in the center of the network while playing an intermediary role.4)Energy consumption,industrialization,per capita GDP,urbanization,science and techno-logy,and productivity are found to be the most influential variables in the spatial differentiation of ICEI,and their combination in-creased the explanatory power of the geographic variation of ICEI.Finally,through the analysis of differences and connections in urban carbon emissions under different economic levels and ICEI,the study suggests joint carbon reduction strategies,which are centered on carbon transfer,financial support,and technological assistance among cities.
基金Supported by the National Natural Science Foundation of China(Nos.42302155,42072169,42072235)the Natural Science Foundation of Shandong Province(No.ZR2023QD016)+2 种基金the China Postdoctoral Science Foundation(No.2022M713461)the Qingdao Postdoctoral Application Research Funds(No.QDBSH20220202067)the Fundamental Research Funds for the Central Universities(No.22CX06005A)。
文摘A transfer zone in rift basins preserves important information on regional tectonic evolution and plays significant roles in hydrocarbon accumulation.Based on the systematic analysis of 3D seismic data and hydrocarbon accumulation conditions,the geometry,kinematics,and reservoir control of a large synthetic overlapping transfer zone in the south of the Wenchang A subsag in the Zhujiang(Pearl)River Mouth basin were investigated.Results indicate that the development and evolution of the transfer zone was controlled by the interaction between pre-existing faults and regional stress transformation.The intense rifting of the main faults of the transfer zone controlled the development of source rocks and faultcontrolled slope break paleogeomorphology.The strike-slip overprint since the Oligocene is conducive to the formation of a large-scale fault-anticline trap,and the secondary faults in the transfer zone contribute to the hydrocarbon transportation.The conjugate intersection area of the NE-and NW-trending faults offers more opportunity for hydrocarbon migration and accumulation.
基金Supported by the National Natural Science Foundation of China(91528303)CNOOC Technology Project(2021-KT-YXKY-05).
文摘The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high-resolution 3D seismic,logging and core data of Pearl River Mouth Basin(PRMB),this paper dissected the shelf-edge delta to deep-water fan(SEDDF)depositional system in the Oligocene Zhuhai Formation of Paleogene in south subsag of Baiyun Sag,and revealed the complex coupling relationship from the continental shelf edge to deep-water fan sedimentation and its genetic mechanisms.The results show that during the deposition of the fourth to first members of the Zhuhai Formation,the scale of the SEDDF depositional system in the study area showed a pattern of first increasing and then decreasing,with deep-water fan developed in the third to first members and the largest plane distribution scale developed in the late stage of the second member.Based on the development of SEDDF depositional system along the source direction,three types of coupling relationships are divided,namely,deltas that are linked downdip to fans,deltas that lack downdip fans and fans that lack updip coeval deltas,with different depositional characteristics and genetic mechanisms.(1)Deltas that are linked downdip to fans:with the development of shelf-edge deltas in the shelf area and deep-water fans in the downdip slope area,and the strong source supply and relative sea level decline are the two key factors which control the development of this type of source-to-sink(S2S).The development of channels on the continental shelf edge is conducive to the formation of this type of S2S system even with weak source supply and high sea level.(2)Deltas that lack downdip fans:with the development of shelf edge deltas in shelf area,while deep water fans are not developed in the downdip slope area.The lack of“sources”and“channels”,and fluid transformation are the three main reasons for the formation of this type of S2S system.(3)Fans that lack updip coeval deltas:with the development of deep-water fans in continental slope area and the absence of updip coeval shelf edge deltas,which is jointly controlled by the coupling of fluid transformation at the shelf edge and the“channels”in the continental slope area.
基金The National Natural Science Foundation of China under contract No.42276066the Key Research and Development Program(International Science and Technology Cooperation Development Program)of Hainan Province under contract No.GHYF2022009the Youth Innovation Promotion Association of CAS under contract No.2018401.
文摘Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift normal fault through detailed seismic interpretation and fault modeling.A total of 289 post-rift normal faults were identified in the study area and can be classified into four types:(1)isolated normal faults above the carbonate platform;(2)isolated normal faults cutting through the carbonate platform;(3)conjugate normal faults,and(4)connecting normal faults.Throw distribution analysis on the fault planes show that the vertical throw profiles of most normal fault exhibit flat-topped profiles.Isolated normal faults above the carbonate platform exhibit roughly concentric ellipses with maximum throw zones in the central section whereas the normal faults cutting through the carbonate platform miss the lowermost section due to the chaotic seismic reflections in the interior of the carbonate platform.The vertical throws of conjugate normal faults anomalously decrease toward their intersection region on the fault plane whereas the connecting normal faults present two maximum throw zones in the central section of the fault plane.According to the symmetric elliptical distribution model of fault throw,an estimation was made indicating that normal faults cutting through the carbonate platform extended downward between-1308 s and-1780 s(two-way travel time)in depth and may not penetrate the entire Liuhua carbonate platform.Moreover,it is observed that the distribution of karst caves on the top of the carbonate platform disaccord with those of hydrocarbon reservoirs and the post-rift normal faults cutting through the carbonate platform in the study area.We propose that these karst caves formed most probably by corrosive fluids derived from magmatic activities during the Dongsha event,rather than pore waters or hydrocarbons.
文摘THIRTY-FOUR years ago,the tallest building in Shanghai’s Pudong area was the Fire Watchtower on Dongchang Road.Its height was merely 24 meters.It was matched by Pudong’s GDP,which was a little over RMB six billion.Today,the tallest building in Pudong is the Shanghai Tower at a whopping height of 632 meters,and the skyline is full of majestic skyscrapers,such as the Oriental Pearl Tower and Shanghai World Financial Center.Proportionately,the district’s GDP has rocketed to over RMB 1.67 trillion.Reform and opening-up,started in 1978,has brought new vitality and prosperity,along with dramatic changes.
基金Under the auspices of the National Natural Science Foundation of China(No.41930646)Guangdong Natural Science Foundation(No.2022A1515011572)。
文摘Container ports and hinterland manufacturing are two important forces of the local participation in economic globalization.This study,taking the Pearl River Delta(PRD),China with an export-oriented economy as an example,applies Huff and panel regres-sion models to evaluate the impact of hinterland manufacturing on the development of container ports during the period of 1993–2019.The results show that 1)the spatial patterns of hinterlands for hub ports help to determine the distribution range and scale of economic variables that affect port throughput;2)the hinterland’s gross manufacturing output has universally positive influence on port through-put,wherein export-oriented processing and the entire manufacturing industry have significantly positive impact on port throughput in 1993–2011 and 2001–2019,respectively;3)the two internal structural factors related to an export-oriented economy,labor-intensive sectors and foreign-funded terminals,have positively moderate the direct influence of hinterland manufacturing on port throughput.Our results highlight the importance of local context in understanding port-manufacturing relationship in developing economies.Based on our findings,policy implications are further proposed to enhance port network organization in PRD.
基金the"14 th Five-year"Plan Project for the Development of Philosophy and Social Sciences of Guangzhou(2023GZGJ83)the Guangdong Ploytechnic of Industry and Commerce Project(2023-SKJ-20).
文摘Urban night tourism is a new form of urban tourism development and an important driving force for the prosperity of urban night economy.As the most prestigious business card among many night tour projects in Guangzhou,the Pearl River water night tour has contributed to the development of Guangzhou s night economy,which cannot be underestimated.However,in the process of rapid development,there are also problems such as diversified operators,insufficient integration of intangible cultural elements,excessive commercial attributes,issues of tourism facilities and service facilities.Under the new stage of integrated development of culture and tourism,how to use mutual promotion of culture and tourism in the Pearl River night tour to seek innovative paths for high-quality development in the future is the main problem expected to be solved in this paper.Therefore,based on the perspective of culture and tourism integration,this paper analyzes the general situation and development status of the Pearl River night tour,and proposes five development strategies:the overall planning of culture and tourism integration,the deep integration of intangible cultural elements,the balance of commercial attributes and tourism attributes,the high integration of culture,business,tourism and education,and the creation of tourism atmosphere,in order to provide inspiration for the healthy,orderly and high-quality development of the Pearl River night tour.
文摘Shanghai,a metropolis in east China that is leading the development of the Yangtze River Delta region is emerging as a powerhouse in the growth of new quality productive forces.Developing new quality productive forces has been listed as one of the important goals for the government in 2024.
文摘Background: Early marriage is prevalent in Middle Eastern culture. The objective of this study was to investigate the pregnancy outcomes of married pregnant adolescents in a prosperous and highly developed Middle Eastern society, when they receive sufficient prenatal care and social assistance. Methods: A retrospective analysis was performed on the Peristat-based Maternal-Newborn registry utilizing hospital data acquired from four main governmental hospitals in Qatar. The study analyzed the pregnancy outcomes of young adults [ages 20 - 24) who experienced their first pregnancy and compared them to the pregnancy outcomes of adolescents aged 15 to 19 years old. Results: The study comprised a cohort of 3152 pregnant married women. This cohort included 2674 women between the ages of 20 and 24, as well as 478 adolescents aged 15 to 19 years old. In comparison to the young adult group, the non-Qatari population in the adolescent group was significantly higher (78.6% (376/478) vs. 71.5% (1914/2674), p-value = 0.003). Other Arab nationalities accounted for more than half of the adolescent population. All the mothers were married, did not use alcohol, and were nonsmokers. There were no documented mothers under the age of 15. Attending antenatal clinics was significantly higher in the adolescent group (p < 0.001). There was no significant difference in the mean gestational age at birth between adolescents and young adults (38.5 ± 2.3 weeks vs. 38.7 ± 2.1 weeks, p = 0.06). Furthermore, adolescent mothers had a higher rate of low birth weight (13.6% vs. 10.4%, p < 0.001) than young mothers. There was a non-statistically significant rise in pre-eclampsia incidence. Other unfavorable pregnancy outcomes were less common among them, such as diabetes, operative vaginal delivery, caesarean section, stillbirth, NICU hospitalization, and an Apgar score of less than 7 at five minutes. There were no maternal deaths;however, there was a comparable rate of neonatal in-hospital mortality. Conclusion: Pregnancy during adolescence may not relate to significant problems in a well-tolerant culture that ensures dedicated antenatal and social support.
基金The Ocean Special Funds for Scientific Research on Public Causes under contract No.201105001-2the National Basic Research Program(973 Program)of China under contract No.2013CB956502the National Natural Science Foundation of China under contract Nos 41376044,41276083 and 41476049
文摘Real-time observations in the field and numerical simulations（with Delft3D） were combined to study the formation, distribution and the relevant influencing factors of turbidity maximum（TM） in the Zhujiang（Pearl River） Estuary（ZE）. The spatial distribution pattern of the TM varies with the longitudinal distributions of salinity and suspended sediment concentration（SSC）. The SSC is enhanced and the TM is intensified during dry seasons,whereas the center of the TM moves upstream by a distance of 10 km during wet seasons. The formation of the TM is influenced by a complex combination of numerous factors, including tides, river discharges and topography, wherein sediment resuspension and vertical circulation dominate the formations and variability of the TM.
基金The National Key Research and Development Progam of China under contract No.2017YFA0603003the National Basic Research Program(973 Program)of China under contract No.2015CB954002+3 种基金the Public Science and Technology Research Funds Project of Ocean under contract No.201505003the National Natural Science Foundation of China under contract Nos41676170,41676172,41476155,41621064 and 41406202the Project of State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,State Oceanic Administration of China under contract No.SOEDZZ1801the Research Startup Project of Nanjing Instiute of Geography and Limnology,Chinese Academy of Sciences under contract No.Y7SL051001
文摘The distributions of estuarine colored dissolved organic matter（CDOM）are the combined results of physicalbiogeochemical processes.Remote sensing is needed to monitor highly dynamically estuarine CDOM.Using in situ data from four seasonal cruises,an algorithm is developed to estimate CDOM absorption coefficient at 400nm（aCDOM（400））in the Zhujiang（Pearl River）Estuary（ZJE）.The algorithm uses band ratios of Rrs（667）/Rrs（443）and Rrs（748）/Rrs（412）.By applying it to moderate resolution imaging spectroradiometer onboard Aqua satellite（MODIS/Aqua）data from 2002 to 2014,seasonal climatology aCDOM（400）in the ZJE is calculated.CDOM distributions are majorly influenced by water discharge from the Zhujiang River and underwater topography.Along the section vertical to a water depth gradient,the seasonal aCDOM（400）exponentially decreased（y=aebx,b〈0）,but with great differences among seasons.Riverine fresh water is the primary source of CDOM in the ZJE.Fulvic acid fraction decreases with increasing salinity.Using developed algorithms,conservative CDOM mixing equation,and river discharge,effective riverine end-member concentration and flux of dissolved organic carbon（DOC）in summer and winter from 2002 to 2014 are first estimated from the MODIS/Aqua data.Both effective riverine end-member DOC concentration and flux are positively related to the river discharge,significantly in summer with R-2 of 0.698 for concentration and 0.965 7 for flux.
基金The National Natural Science Foundation of China under contract Nos 41776072,41476039,41674092 and 41676045the Geotectonic Evolution of China and Compilation of International Asian Geotectonic Map under contract No.DD20190364the Marine Basic Geological Survey Project under contract No.DD20190627
文摘The Yangjiang-Yitongdong Fault (YJF) is an important NW-trending regional fault, which divides the Zhujiang (Pearl) River Mouth Basin (ZRMB) into western and eastern segments. In Cenozoic, the northern continental margin of the South China Sea (SCS) underwent continental rifting, breakup, seafloor spreading and thermal subsidence processes, and the Cenozoic activities of YJF is one part of this series of complex processes. Two long NW-trending multichannel seismic profiles located on both sides of the YJF extending from the continental shelf to Continent-Ocean Boundary (COB) were used to study the tectonic and sedimentary characteristics of western ZRMB. Using the 2D-Move software and back-stripping method, we constructed the balance cross-section model and calculated the fault activity rate. Through the comprehensive consideration of tectonic position, tectonic evolution history, featured structure, and stress analysis, we deduced the activity history of the YJF in Cenozoic. The results showed that the YJF can be divided into two segments by the central uplift belt. From 65 Ma to 32 Ma, the YJF was in sinistral motion as a whole, inherited the preexisting sinistral motion of Mesozoic YJF, in which, the southern part of YJF was mainly in extension activity, controlling the formation and evolution of Yunkai Low Uplift, coupled with slight sinistral motion. From 32 Ma to 23.8 Ma, the sinistral motion in northern part of YJF continued, while the sinistral motion in southern part began to stop or shifted to a slightly dextral motion. After 23.8 Ma, the dextral motion in southern part of YJF continued, while the sinistral motion in northern part of YJF gradually stopped, or shifted to the slightly dextral motion. The shift of the YJF strike-slip direction may be related to the magmatic underplating in continent-ocean transition, southeastern ZRMB. According to the analysis of tectonic activity intensity and rift sedimentary structure, the activities of YJF in Cenozoic played a regulating role in the rift extension process of ZRMB.
基金Under the auspices of National Natural Science Foundation of China(No.41271177)Guangdong Natural Science Foundation(No.S2012010008902)
文摘In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. The traditional gravity model assumes ideal conditions, but these preconditions and their results often do not exist in realistic conditions. Thus, we used a modified gravity model to characterize the city contacts within a specific region. This model considers factors such as intercity complementarities, government intervention, and the diversity of the transportation infrastructure which is characterized as the transportation distance instead of the traditional Euclidean distance. We applied this model to an empirical study of city contact in the Zhujiang(Pearl) River Delta(PRD) of China. The regression results indicated that the modified gravity model could measure city contact more accurately and comprehensively than the traditional gravity model, i.e., it yielded a higher adjusted R2 value(0.379) than the traditional gravity model result(0.259). Our study also suggests that, in addition to urban-regional and metropolitan development, the complementarities of the basic functions of cities at the administrative and market levels, as well as the corporeal and immaterial levels, play very significant roles in the characterization of city contact. Given the complexity of city contact, it will be necessary to consider more relevant influential factors in the modified gravity model to characterize the features of city contact in the future.
基金The Knowledge Innovation Project of Chinese Academy of Sciences under contract Nos KZCX2-YW-Q07, KZCX2-YW-T001, KZCX2-YW-213 and SQ200805the National Natural Science Foundation of China under contract Nos U0633007, 40906057 and 40531006
文摘Chemometric approach based on principal component analysis（PCA） was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River（Pearl River） Estuary and adjacent waters（ZREAW） in the South China Sea. The PCA result shows that the ZREAW can be divided into different zones according to the principal components and geographical locations of the study stations,and indicates that there are distinct regional variances on environmental features and the corresponding phytoplankton biomass and community structures among different areas. The spatial distribution of ecological features was implied to be influenced by various degrees of the different water resources,such as the Pearl River discharges,the coastal current and the oceanic water from the South China Sea. The variation of the biomass maximum zone and the complex impacts on the spatial distributions of phytoplankton biomass and production were also evaluated.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences No.XDA11010404the National Natural Science Foundation of China under contract Nos 41375096,41175079 and 41405082the Macao Meteorological and Geophysical Bureau Project under contract No.9231048
文摘Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is used to adaptively decompose the sea level time series in order to extract the secular trend component. Then the linear relationship between the global mean sea level （GMSL） change and the Zhujiang （Pearl） River Delta （PRD） sea level change is calculated： an increase of 1.0 m in the GMSL corresponds to a 1.3 m （uncertainty interval from 1.25 to 1.46 m） increase in the PRD. Based on this relationship and the GMSL rise projected by the Coupled Model Intercomparison Project Phase 5 under three greenhouse gas emission scenarios （representative concentration pathways, or RCPs, from low to high emission scenarios RCP2.6, RCP4.5, and RCP8.5）, the PRD sea level is calculated and projected for the period 2006-2100. By around the year 2050, the PRD sea level will rise 0.29 （0.21 to 0.40） m under RCP2.6, 0.31 （0.22 to 0.42） m under RCP4.5, and 0.34 （0.25 to 0.46） m under RCP8.5, respectively. By 2100, it will rise 0.59 （0.36 to 0.88） m, 0.71 （0.47 to 1.02） m, and 1.0 （0.68 to 1.41） m, respectively. In addition, considering the extreme value of relative sea level due to land subsidence （i.e., 0.20 m） and that obtained from intermonthly variability （i.e., 0.33 m）, the PRD sea level will rise 1.94 m by the year 2100 under the RCP8.5 scenario with the upper uncertainty level （i.e., 1.41 m）. Accordingly, the potential submerged area is 8.57x103 km2 for the PRD, about 1.3 times its present area.
基金Supported by the National Natural Science Foundation of China(No. 40976106)the Science Foundation Program of Guangdong Ocean University (No. 1012339)the Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics of Second Institute of Oceanography, SOA (No. SODE1203)
文摘Although remote sensing data have been used to estimate total suspended matter （TSM） in coastal waters, it has limitations when applied to estuary waters in low spatial resolution situations. The spatial resolution of ocean color satellites such as SeaWiFS and MODIS is usually -1 km, and therefore is not adequate for small, local-scale areas such as the Zhujiang （Pearl） River estuary. In contrast, 30 m-resolution EO-1 Hyperion imagery has potential for studying TSM in localized areas. We measured the surface spectral radiance reflectance of the river estuary water in the visible and near infra-red spectral range. Sensitivity analysis indicated that the ratio of remote sensing reflectance at 813 nm （Rrs（813）） to reflectance at 559 nm （Rrs（559）） could be used to estimate TSM concentration, and a linear relationship was established between the ratio and in-situ TSM concentration. We applied the linear relationship to Hyperion imagery to map TSM concentration in the estuary. The Hyperion imagery provided sufficient spatial resolution to detect spatiotemporal changes in TSM concentrations in the estuary small estuary area. This study demonstrated the usefulness of Hyperion imagery for mapping the distribution of TSM in estuary waters. Keyword： Hyperion; total suspended matter （TSM）; Zhujiang （Pearl） River estuary
基金granted by the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2008ZX05056-02-02)
文摘Eleven lithofacies and five lithofacies associations were indentified in the Miocene Zhujiang Formation on the basis of detailed core analysis. It could he determined that three depositional types developed, namely submarine fan, basin and deep-water traction current. Six microfacies were further recognized within the fan, including main channels in the inner fan, distributary channels in the middle fan, inter-channels, levees and the outer fan. The lower Zhujiang Formation, mainly sandstone associations, was inner fan and inner-middle fan deposits of the basin fan and the slope fan. The middle part, mainly mudstone associations, was outer fan deposits. With the transgression, the submarine fan was finally replaced by the basinal pelagic deposits which were dominated by mudstone associations, siltstone associations, and deep-water limestone associations. During the weak gravity flow activity, the lower channels, the middle-upper outer fans and basin deposits were strongly modified by the deep-water traction current. The identification of the deep-water traction deposition in Miocene Zhujiang Formation would be of great importance. It could be inferred that the deep- water traction current had been existing after the shelf-break formation since the Late Oligocene （23.8 Ma） in the Baiyun sag, influencing and controlling the sediment composition, the distribution, and depositional processes. It would provide great enlightenment to the paleo-oceanic current circulation in the northern South China Sea.
