The Weber Deep represents a widespread crustal extension system in eastern Indonesia with a huge submarine normal fault system,the Banda Detachment,related to the slab rollback tectonic model(Spakman and Hall,2010;Cum...The Weber Deep represents a widespread crustal extension system in eastern Indonesia with a huge submarine normal fault system,the Banda Detachment,related to the slab rollback tectonic model(Spakman and Hall,2010;Cummins et al.,2020).However,the cause of tectonic extension remains debated(e.g.,Audley-Charles et al.,1972;McCaffrey,1988;Das,2004;Spakman and Hall,2010;Pownall et al.,2013;Cummins et al.,2020;Hutchings and Mooney,2021;Shah et al.,2023).展开更多
In contrast to the Pacific and Atlantic Oceans,the Indian Ocean has lacked in-situ observations of wind profiles over open sea areas for decades.In 2021,a shipborne coherent Doppler lidar(CDL)was used to observe in-si...In contrast to the Pacific and Atlantic Oceans,the Indian Ocean has lacked in-situ observations of wind profiles over open sea areas for decades.In 2021,a shipborne coherent Doppler lidar(CDL)was used to observe in-situ wind profiles in the eastern tropical Indian Ocean.This equipment successfully captured low-level jets(LLJs)in the region,and their characteristics were thoroughly analyzed.Results reveal that the observed wind speed of LLJs in the eastern Indian Ocean ranges from 6 m s^(-1) to 10 m s^(-1) during the boreal winter and spring seasons,showing a height range of 0.6 to 1 km and two peak times at 0800 and 2000 UTC.This wind shear is weaker than that in land or offshore areas,ranging from 0 s^(-1) to 0.006 s^(-1).Moreover,the accuracy of the CDL data is compared to that of ERA5 data in the study area.The results indicate that the zonal wind from ERA5 data significantly deviated from the CDL measurement data,and the overall ERA5 data are substantially weaker than the in-situ observations.Notably,ERA5 underestimates northwestward LLJs.展开更多
Minimum temperatures have remarkable impacts on tree growth at high-elevation sites on the Tibetan Plateau,but the shortage of long-term and high-resolution paleoclimate records inhibits understanding of recent minimu...Minimum temperatures have remarkable impacts on tree growth at high-elevation sites on the Tibetan Plateau,but the shortage of long-term and high-resolution paleoclimate records inhibits understanding of recent minimum temperature anomalies.In this study,a warm season(April–September)reconstruction is presented for the past 467 years(1550–2016)based on Sabina tibetica ring-width chronology on the Lianbaoyeze Mountain of the central eastern Tibetan Plateau.Eight warm periods and eight cold periods were identified.Long-term minimum temperature variations revealed a high degree of coherence with nearby reconstructions.Spatial correlations between our reconstruction and global sea surface temperatures suggest that warm season minimum temperature anomalies in the central eastern Tibetan Plateau were strongly influenced by large-scale ocean atmospheric circulations,such as the El Ni?o-Southern Oscillation and the Atlantic Multidecadal Oscillation.展开更多
Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Gl...Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Global Positioning System(GPS)soundings in the eastern tropical Indian Ocean and South China Sea through a simultaneous balloon-borne inter-comparison of different radiosonde types.Our results indicate that the temperature and relative humidity(RH)measurements of GPS-TanKong(GPS-TK)radiosonde(used at most stations before 2012)have larger biases than those of ChangFeng-06-A(CF-06-A)radiosonde(widely used in current observation)when compared to reference data from Vaisala RS92-SGP radiosonde,with a warm bias of 5℃and dry bias of 10%during daytimes,and a cooling bias of-0.8℃and a moist bias of 6%during nighttime.These systematic biases are primarily attributed to the radiation effects and altitude deviation.An empirical correction algorithm was developed to retrieve the atmospheric temperature and RH profiles.The corrected profiles agree well with that of RS92-SGP,except for uncertainties of CF-06-A in the stratosphere.These correction algorithms were applied to the GPS-TK historical sounding records,reducing biases in the corrected temperature and RH profiles when compared to radio occultation data.The correction of GPS-TK historical records illustrated an improvement in capturing the marine atmospheric structure,with more accurate atmospheric boundary layer height,convective available potential energy,and convective inhibition in the tropical ocean.This study contributes significantly to improving the quality of GPS radiosonde soundings and promotes the sharing of observation in the eastern tropical Indian Ocean and South China Sea.展开更多
Two thousand years ago,the Silk Road connecting Xi’an to Rome was a long journey that took more than a year.Today,China Eastern Airlines makes the journey in just over 10 hours with the world’s most advanced wide-bo...Two thousand years ago,the Silk Road connecting Xi’an to Rome was a long journey that took more than a year.Today,China Eastern Airlines makes the journey in just over 10 hours with the world’s most advanced wide-body airliner.The power of civil aviation has made the Silk Road more convenient than ever before.Over the last decade of the Belt and Road Initiative(BRI),the“Aerial Silk Road”has connected more and more destinations around the world.展开更多
The aim of this study was to verify the existence of business and strategic intelligence policies at the level of Congolese companies and at the state level, likely to foster progress and healthy development in the ea...The aim of this study was to verify the existence of business and strategic intelligence policies at the level of Congolese companies and at the state level, likely to foster progress and healthy development in the east of the DRC. The study was based on a mixed perspective consisting of objective analysis of quantitative data and interpretative analysis of qualitative data. The results showed that business and strategic intelligence policies have not been established at either company or state level, as this is an area of activity that is not known to the players in companies and public departments, and there are no units or offices in their organizational structures responsible for managing strategic information for competitiveness on the international market. In addition, there is a real need to establish strategic information management units within companies, upstream, and to set up a national strategic information management department or agency to help local companies compete in the marketplace, downstream. This reflects the importance and timeliness of building business and strategic intelligence policies to ensure economic progress and development in the eastern DRC. Business and strategic intelligence provides companies with an appropriate tool for researching, collecting, processing and disseminating information useful for decision-making among stakeholders, in order to cope with a crisis or competitive situation. The study suggests a number of key recommendations based on its findings. To the government, it is recommended to establish the national policy of business and strategic intelligence by setting up a national agency of strategic intelligence in favor of local companies;and to companies to establish business intelligence units in their organizational structures in favor of stakeholders to foster advantageous decision-making in the competitive market and achieve progress. Finally, the study suggests that studies be carried out to fully understand the opportunities and impact of business and strategic intelligence in African countries, particularly in the DRC.展开更多
There is great controversy regarding the origin and source of natural gas in the Lower Triassic Feix-ianguan Formation in the Eastern Sichuan Basin.This seriously restricts the study of natural gas dy-namics in the Fe...There is great controversy regarding the origin and source of natural gas in the Lower Triassic Feix-ianguan Formation in the Eastern Sichuan Basin.This seriously restricts the study of natural gas dy-namics in the Feixianguan Formation and thus hampers natural gas exploration in the region,so further study is urgently required.Using experimental tests of natural gas composition,stable isotopes,and noble gas isotopes with gas chromatography(GC)and mass spectrometry(MS)studies of source rock and reservoir asphalt saturated hydrocarbons,the natural gas geochemical characteristics,the genetic identification and a gas-source comparison of the Feixianguan Formation were studied.Then,con-strained by the thermal history,the histories of gas generation and expulsion were restored by basin simulation technology.Finally,a gas accumulation model was established for the Feixianguan Formation.The results showed that(1)the H_(2)S-rich and H2S-poor gas reservoirs of the Feixianguan Formation are distributed on the east and west sides of the Kaijiang-Liangping trough in the Eastern Sichuan Basin,respectively.The carbon and hydrogen isotope compositions of the natural gas in the gas reservoirs are generally heavy and have typical characteristics of high-maturity dry gas reservoirs.(2)The natural gas of the Feixianguan Formation is organic thermogenic gas,which is mainly oil-type gas generated by the secondary cracking of crude oil.The gas-generating parent material is mainly type II kerogen.(3)The natural gas of the Feixianguan Formation in the Eastern Sichuan Basin was mainly generated by argil-laceous source rocks of the Upper Permian Longtan Formation.(4)Natural gas accumulation occurred as follows:the paleo-structure heights were filled with crude oil in the Early Jurassic,and paleo-oil res-ervoirs were formed in the Feixianguan Formation;during the Middle-Late Jurassic,the paleo-oil res-ervoirs were cracked when the reservoir temperatures rose above 160 C,and paleo-gas reservoirs were formed.Since the end of the Late Jurassic,the paleo-gas reservoirs have been adjusted and reformed to form the present-day natural gas reservoirs.These results provide a basis for studying natural gas accumulation dynamics of the Feixianguan Formation in the Eastern Sichuan Basin.展开更多
Seasonal prediction of summer precipitation over eastern China is closely linked to the East Asian monsoon circulation,which is largely affected by the El Niño-Southern Oscillation(ENSO).In this study,results sho...Seasonal prediction of summer precipitation over eastern China is closely linked to the East Asian monsoon circulation,which is largely affected by the El Niño-Southern Oscillation(ENSO).In this study,results show that spring soil moisture(SM)over the Indo-China peninsula(ICP)could be a reliable seasonal predictor for eastern China summer precipitation under non-ENSO conditions.When springtime SM anomalies are present over the ICP,they trigger a structured response in summertime precipitation over most of eastern China.The resultant south-to-north,tri-polar configuration of precipitation anomalies has a tendency to yield increased(decreased)precipitation in the Yangtze River basin and decreased(increased)in South and North China with a drier(wetter)spring soil condition in the ICP.The analyses show that ENSO exerts a powerful control on the East Asian circulation system in the ENSO-decaying summer.In the case of ENSO forcing,the seasonal predictability of the ICP spring SM for eastern China summer precipitation is suppressed.However,in the absence of the influence of ENSO sea surface temperature anomalies from the preceding winter,the SM anomalies over the ICP induce abnormal local heating and a consequent geopotential height response owing to its sustained control on local temperature,which could,in turn,lead to abnormal eastern China summer precipitation by affecting the East Asian summer monsoon circulation.The present findings provide a better understanding of the complexity of summer climate predictability over eastern China,which is of potential significance for improving the livelihood of the people.展开更多
As important atmospheric circulation patterns in Northern Hemisphere(NH),the North Atlantic Oscillation(NAO)and the Western Pacific teleconnection(WP)affect the winter climate in Eurasia.In order to explore the combin...As important atmospheric circulation patterns in Northern Hemisphere(NH),the North Atlantic Oscillation(NAO)and the Western Pacific teleconnection(WP)affect the winter climate in Eurasia.In order to explore the combined effects of NAO and WP on East Asian(EA)temperature,the NAO and WP indices are divided into four phases from 1980−2021:the positive NAO and WP phase(NAO+/WP+),the negative NAO and WP phase(NAO−/WP−),the positive NAO and negative WP phase(NAO+/WP−),the negative NAO and positive WP phase(NAO−/WP+).In the phase of NAO+/WP+,the low geopotential height(GH)stays in north of EA at 50°−80°N;the surface air temperature anomaly(SATA)is 0.8−1℃lower than Southern Asian.In the phase of NAO−/WP−,the center of high temperature and GH locate in the northeast of EA;the cold air spreads to Southern Asia,causing the SATA decreases 1−1.5℃.In the phase of NAO+/WP−,the high GH belt is formed at 55°−80°N.Meanwhile,the center of high SATA locates in the north of Asia that increases 0.8−1.1℃.The cold airflow causes temperature dropping 0.5−1℃in the south of EA.The SATA improves 0.5−1.5℃in south of EA in the phase of NAO−/WP+.The belt of high GH is formed at 25°−50°N,and blocks the cold air which from Siberia.The NAO and WP generate two warped plate pressure structures in NH,and affect the temperature by different pressure configurations.NAO and WP form different GH,and GH acts to block and push airflow by affecting the air pressure,then causes the temperature to be different from the north and south of EA.Finally,the multiple linear regression result shows that NAO and WP are weakened by each other such as the phase of NAO+/WP+and NAO−/WP−.展开更多
The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment po...The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.展开更多
The continuous development of agricultural technologies and produces trade and updated state reforms strongly shape the dominant organizing styles of local agriculture production.Since the end of the 1970s,rural China...The continuous development of agricultural technologies and produces trade and updated state reforms strongly shape the dominant organizing styles of local agriculture production.Since the end of the 1970s,rural China has witnessed a drastic agriculture transformation featured by de-collectivization,and recently in Taicang,a developed city in the eastern China,a kind of new cooperative farms have replaced the smallholders by pooling households’contracted farmland,signaling a new shift tendency towards agriculture recollectivization that is distinctive compared to other countries.Given the state governance’s leadership in promoting this latest transformation,drawing on the theoretical concept of‘governmentality’that is powerful in understanding how to govern the society to meet certain objectives,this paper examines the accurate processes of agriculture re-collectivization in Taicang City based on the methods of semi-structured interview and participant observation.Our research shows that the China’s tax-sharing and relevant reforms in the 1990s framed a new governance structure in line with the new mode of‘governmentality’closely linked to‘advanced liberalism’,creating the responsibility shift from central to local governments and a set of evaluation technologies,and guiding various actors to engage in the agriculture re-collectivization practice in Taicang.Importantly,the considerable subsidies and the impressive extension services in terms of farming personnel training and agricultural techniques diffusion underpin the normal running of cooperative farms and contribute to the local implementation of national strategy of agriculture modernization.We argue that the combination of distinctive institutional arrangement of rural land owned by village collectives in China and the burgeoning local economy allows the developed areas to re-collectivizing the agriculture production for ensuring grain self-sufficiency rather than capturing more share in global agriculture products trade,and that the cooperative farms in our case have been deeply integrated into the‘modern procurement system’and become more sensitive to market fluctuation,requiring rural extension service to transform towards farms’capacity building for maintaining the longterm development momentum.展开更多
Introduction: Pregnancy resulting from rape is a public health and sexual and reproductive health issue, especially among minors. Rape can be perpetrated with or without physical restraint. The objective of the presen...Introduction: Pregnancy resulting from rape is a public health and sexual and reproductive health issue, especially among minors. Rape can be perpetrated with or without physical restraint. The objective of the present study is to highlight the prevalence of physical coercion leading to pregnancy and the associated maternal-fetal complications. Methodology: This was a comparative descriptive and analytical cross-sectional study of complications associated with post-rape pregnancy by physical restraint among minors who were treated at the General Reference Hospital of Panzi over a two-year period from June 2020 to June 2022. A total of 140 minor survivors of violence with pregnancy were included in the study. Data were collected using a questionnaire, coded and analyzed in Excel and XLSTAT version 2014. Results: The prevalence of physical constraints was 65%. After mulltivariate analyses, denial of pregnancy (ORa: 9.64 95% CI: 1.1 - 81.2;p-value: 0.0370), attempted abortion (ORa: 56.1 95% CI: 1.5 - 2027.6;p-value: 0.0278) and agitation during delivery (ORa: 88.7 95% CI: 4.5 - 1715;p-value: 0.0030) were the complications associated with pregnancy in minors who experienced physical restraint rape. In addition, BMI was a factor in reducing the risk of physical restraint rape at the ORa of 0.5054 [0.3;0.8];p 0.006). Conclusion: Pregnancy among minors is a reality and occurs in a situation of physical coercion in the eastern Democratic Republic of Congo. These pregnancies are often associated with complications that require an intensive management system since they can jeopardize the maternal-fetal prognosis of minors.展开更多
We have been pleased that our paper Geological mapping and mining prospecting in the Aouli inlier(Eastern Meseta,Morocco) based on remote sensing and geographic information systems(GIS) was of interest to our colleagu...We have been pleased that our paper Geological mapping and mining prospecting in the Aouli inlier(Eastern Meseta,Morocco) based on remote sensing and geographic information systems(GIS) was of interest to our colleagues who commented it in China Geology 5(2022) 1–4.展开更多
This study examines the spatio-temporal characteristics of heavy precipitation forecasts in eastern China from the European Centre for Medium-Range Weather Forecasts(ECMWF) using the time-domain version of the Method ...This study examines the spatio-temporal characteristics of heavy precipitation forecasts in eastern China from the European Centre for Medium-Range Weather Forecasts(ECMWF) using the time-domain version of the Method for Object-based Diagnostic Evaluation(MODE-TD). A total of 23 heavy rainfall cases occurring between 2018 and 2021 are selected for analysis. Using Typhoon “Rumbia” as a case study, the paper illustrates how the MODE-TD method assesses the overall simulation capability of models for the life history of precipitation systems. The results of multiple tests with different parameter configurations reveal that the model underestimates the number of objects’ forecasted precipitation tracks, particularly at smaller radii. Additionally, the analysis based on centroid offset and area ratio tests for different classified precipitation objects indicates that the model performs better in predicting large-area, fast-moving, and longlifespan precipitation objects. Conversely, it tends to have less accurate predictions for small-area, slow-moving, and shortlifespan precipitation objects. In terms of temporal characteristics, the model overestimates the forecasted movement speed for precipitation objects with small-area, slow movement, or both long and short lifespans while underestimating it for precipitation with fast movement. In terms of temporal characteristics, the model tends to overestimate the forecasted movement speed for precipitation objects with small-area, slow movement, or both long and short lifespans while underestimating it for precipitation with fast movement. Overall, the model provides more accurate predictions for the duration and dissipation of precipitation objects with large-area or long-lifespan(such as typhoon precipitation) while having large prediction errors for precipitation objects with small-area or short-lifespan. Furthermore, the model’s simulation results regarding the generation of precipitation objects show that it performs relatively well in simulating the generation of large-area and fast-moving precipitation objects. However, there are significant differences in the forecasted generation of small-area and slow-moving precipitation objects after 9 hours.展开更多
Medicinal plants play a major role in meeting people’s medical and health needs, especially in developing countries. However, due to a lack of access to modern veterinary facilities, poor visibility of animal health ...Medicinal plants play a major role in meeting people’s medical and health needs, especially in developing countries. However, due to a lack of access to modern veterinary facilities, poor visibility of animal health personnel, and high prices of orthodox medicines, most farmers rely on traditional healers and the administration of medicinal plants to treat livestock ailments. The present study was conducted to document Ethnopharmacological knowledge of medicinal plants used to manage livestock ailments in three rural communities of the Eastern Cape. This study was carried out in three rural communities between July 2009 and February 2010. Data were collected by administering pre-tested semi-structured questionnaires and participative field observations. For the interviews, a sample of 48 knowledgeable respondents was purposively selected. Data were analyzed using descriptive and inferential statistics, determination of information consensus factor, and fidelity level. A total of 12 medicinal plants belonging to 9 families were used by local people to cure different ailments. A high number of medicinal plants were claimed by males compared to females. Roots and barks were the major plant parts used, and the least were leaves (27.3%). Six plants were used to treat diarrhea and fertility, five plants to treat wounds, and two plants to treat scabs. This study has shown that Eastern Cape flora is rich with various plants which could be used to replace orthodox drugs. Further studies are needed to determine the minimum inhibitory concentrations, biological activities, and toxicities and characterize the plant’s chemical compounds.展开更多
Through core observation,thin section identification,X-ray diffraction analysis,scanning electron microscopy,and low-temperature nitrogen adsorption and isothermal adsorption experiments,the lithology and pore charact...Through core observation,thin section identification,X-ray diffraction analysis,scanning electron microscopy,and low-temperature nitrogen adsorption and isothermal adsorption experiments,the lithology and pore characteristics of the Upper Carboniferous bauxite series in eastern Ordos Basin were analyzed to reveal the formation and evolution process of the bauxite reservoirs.A petrological nomenclature and classification scheme for bauxitic rocks based on three units(aluminum hydroxides,iron minerals and clay minerals)is proposed.It is found that bauxitic mudstone is in the form of dense massive and clastic structures,while the(clayey)bauxite is of dense massive,pisolite,oolite,porous soil and clastic structures.Both bauxitic mudstone and bauxite reservoirs develop dissolution pores,intercrystalline pores,and microfractures as the dominant gas storage space,with the porosity less than 10% and mesopores in dominance.The bauxite series in the North China Craton can be divided into five sections,i.e.,ferrilite(Shanxi-style iron ore,section A),bauxitic mudstone(section B),bauxite(section C),bauxite mudstone(debris-containing,section D)and dark mudstone-coal section(section E).The burrow/funnel filling,lenticular,layered/massive bauxite deposits occur separately in the karst platforms,gentle slopes and low-lying areas.The karst platforms and gentle slopes are conducive to surface water leaching,with strong karstification,well-developed pores,large reservoir thickness and good physical properties,but poor strata continuity.The low-lying areas have poor physical properties but relatively continuous and stable reservoirs.The gas enrichment in bauxites is jointly controlled by source rock,reservoir rock and fractures.This recognition provides geological basis for the exploration and development of natural gas in the Upper Carboniferous in the study area and similar bauxite systems.展开更多
Colored dissolved organic matter(CDOM)is a crucial constituent that affects the optical absorption properties of seawater.Owing to the relatively limited measured data on the spatial distribution characteristics of CD...Colored dissolved organic matter(CDOM)is a crucial constituent that affects the optical absorption properties of seawater.Owing to the relatively limited measured data on the spatial distribution characteristics of CDOM in the tropical eastern Indian Ocean,this study analyzes the optical absorption characteristics of CDOM in the southeast Indian Ocean using the data collected during four seasons from 2013 to 2017.This work also systematically describes the seasonal horizontal and vertical distribution characteristics of CDOM in this area and conducts a preliminary analysis of the relevant factors affecting CDOM absorption characteristics in this region.Results indicate that the CDOM ag(440)during summer was remarkably lower than that in the coastal waters of Europe and coastal waters of China but slightly higher than that in the western and southeast Pacific.The spatial distribution of surface CDOM shows remarkable seasonal differences,and the spatial distribution characteristics of CDOM in the 5°S,92°E region differ between spring/summer and autumn/winter.The values of ag(400)and ag(440)are weak/strong at a surface/subsurface level of 100 m,with differences found between summer and winter.The correlation of CDOM with temperature,salinity,and chlorophyll-a concentration is relatively low,indicating that CDOM is an independent driving mechanism influenced by phytoplankton degradation,photobleaching,and water mixing.展开更多
Aptian is characterized by widespread deposition of organic-rich sediment.The Aptian bitumen limestone horizon,which is thin decimetre-thick sequences,locally crops out in the Kircaova area,Eastern Black Sea Region(Ea...Aptian is characterized by widespread deposition of organic-rich sediment.The Aptian bitumen limestone horizon,which is thin decimetre-thick sequences,locally crops out in the Kircaova area,Eastern Black Sea Region(Eastern Pontides).They are well correlated with Aptian bitumen limestone in the other Tethys Reams.They are proposed as episodes of increased organic matter.However,background factors controlling organic matter enrichment are poorly known.In this study,we present new inorganic geochemistry,including trace elements,rare earth elements(REE),redox-sensitive elements(RSE),stable-isotopes(δ~(18)O andδ~(13)C),and total organic carbon(TOC).We integrated new geochemical data with existing stratigraphy,paleontology,and organic chemistry data to provide new insight into the depositional environment and paleoclimate conditions during Aptian.The lacustrine bitumen limestone(LBL)samples have variedδ~(13)C(ave.-1.45‰)andδ~(18)O(ave.-4.50‰).They possess distinct REE patterns,with an average of REE(ave.14.45 ppm)and Y/Ho(ave.35)ratios.In addition,they have variable Nd/YbN(0.28-0.81;ave.0.56)and Ce/Ce*(0.68-0.97;ave.0.86),and relatively high Eu^(*)/Eu(1.23-1.53;ave.1.35).They display seawater signatures with reduced oxygen conditions.The enrichment in RSE(Mo,Cu,Ni,and Zn)and the low Mo/TOC(0.70-3.69;ave.2.41)support a certain degree of water restriction.The high Sr/Ba,Sr/Cu,Ga/Rb,and K/Al records of the LBL facies suggest hot house climatic conditions.The sedimentary environment was probably an isolated basin that is transformed from the marine basin.In addition to depositional conditions,the regional parameters such as the climate,increased run-off period,nutrient levels,alkalinity level,and dominant carbonate producers favored the enrichment in organic matter of LBL facies.Thus,extreme greenhouse palaeoclimate conditions have an important role in organic matter enrichment in the isolated basin.Our results are conformable with the published data from marine,semi-restricted basin,and lacustrine settings in the different parts of the Tethys margin.Thus,this approach provides the first insight into the Aptian greenhouse paleo-climate conditions of the Eastern Black Sea Region,NE Turkey.展开更多
文摘The Weber Deep represents a widespread crustal extension system in eastern Indonesia with a huge submarine normal fault system,the Banda Detachment,related to the slab rollback tectonic model(Spakman and Hall,2010;Cummins et al.,2020).However,the cause of tectonic extension remains debated(e.g.,Audley-Charles et al.,1972;McCaffrey,1988;Das,2004;Spakman and Hall,2010;Pownall et al.,2013;Cummins et al.,2020;Hutchings and Mooney,2021;Shah et al.,2023).
基金supported by the Taishan Scholars Programs of Shandong Province(No.tsqn201909165)the Global Change and Air-Sea Interaction Program(Nos.GASI-04-QYQH-03,GASI-01-WIND-STwin)the National Natural Science Foundation of China(Nos.41876028,42349910).
文摘In contrast to the Pacific and Atlantic Oceans,the Indian Ocean has lacked in-situ observations of wind profiles over open sea areas for decades.In 2021,a shipborne coherent Doppler lidar(CDL)was used to observe in-situ wind profiles in the eastern tropical Indian Ocean.This equipment successfully captured low-level jets(LLJs)in the region,and their characteristics were thoroughly analyzed.Results reveal that the observed wind speed of LLJs in the eastern Indian Ocean ranges from 6 m s^(-1) to 10 m s^(-1) during the boreal winter and spring seasons,showing a height range of 0.6 to 1 km and two peak times at 0800 and 2000 UTC.This wind shear is weaker than that in land or offshore areas,ranging from 0 s^(-1) to 0.006 s^(-1).Moreover,the accuracy of the CDL data is compared to that of ERA5 data in the study area.The results indicate that the zonal wind from ERA5 data significantly deviated from the CDL measurement data,and the overall ERA5 data are substantially weaker than the in-situ observations.Notably,ERA5 underestimates northwestward LLJs.
基金funded by the National Key Research and Development Program of China(No.2018YFA0605601)Hong Kong Research Grants Council(No.106220169)+1 种基金the National Natural Science Foundation of China(No.42105155,41671042,and 42077417)the National Geographic Society(No.EC-95776R-22)。
文摘Minimum temperatures have remarkable impacts on tree growth at high-elevation sites on the Tibetan Plateau,but the shortage of long-term and high-resolution paleoclimate records inhibits understanding of recent minimum temperature anomalies.In this study,a warm season(April–September)reconstruction is presented for the past 467 years(1550–2016)based on Sabina tibetica ring-width chronology on the Lianbaoyeze Mountain of the central eastern Tibetan Plateau.Eight warm periods and eight cold periods were identified.Long-term minimum temperature variations revealed a high degree of coherence with nearby reconstructions.Spatial correlations between our reconstruction and global sea surface temperatures suggest that warm season minimum temperature anomalies in the central eastern Tibetan Plateau were strongly influenced by large-scale ocean atmospheric circulations,such as the El Ni?o-Southern Oscillation and the Atlantic Multidecadal Oscillation.
基金The Second Tibetan Plateau Scientific Expedition and Research Program under contract No.2019QZKK0102-02the National Natural Science Foundation of China under contract Nos 42230402,92158204,42176026,42076201,41049903,41149908,41249906,41249907,and 41249910+2 种基金the Guangdong Basic and Applied Basic Research Foundation under contract No.2022A1515240069the Marine Economic Development Special Program of Guangdong Province(Six Major Marine Industries):Research and Demonstration of Critical Technologies for Comprehensive Prevention and Control of Natural Disaster in Offshore Wind Farms,China under contract No.29[2023]the Fund of Fujian Provincial Key Laboratory of Marine Physical and Geological Processes under contract No.KLMPG-22-02.
文摘Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Global Positioning System(GPS)soundings in the eastern tropical Indian Ocean and South China Sea through a simultaneous balloon-borne inter-comparison of different radiosonde types.Our results indicate that the temperature and relative humidity(RH)measurements of GPS-TanKong(GPS-TK)radiosonde(used at most stations before 2012)have larger biases than those of ChangFeng-06-A(CF-06-A)radiosonde(widely used in current observation)when compared to reference data from Vaisala RS92-SGP radiosonde,with a warm bias of 5℃and dry bias of 10%during daytimes,and a cooling bias of-0.8℃and a moist bias of 6%during nighttime.These systematic biases are primarily attributed to the radiation effects and altitude deviation.An empirical correction algorithm was developed to retrieve the atmospheric temperature and RH profiles.The corrected profiles agree well with that of RS92-SGP,except for uncertainties of CF-06-A in the stratosphere.These correction algorithms were applied to the GPS-TK historical sounding records,reducing biases in the corrected temperature and RH profiles when compared to radio occultation data.The correction of GPS-TK historical records illustrated an improvement in capturing the marine atmospheric structure,with more accurate atmospheric boundary layer height,convective available potential energy,and convective inhibition in the tropical ocean.This study contributes significantly to improving the quality of GPS radiosonde soundings and promotes the sharing of observation in the eastern tropical Indian Ocean and South China Sea.
文摘Two thousand years ago,the Silk Road connecting Xi’an to Rome was a long journey that took more than a year.Today,China Eastern Airlines makes the journey in just over 10 hours with the world’s most advanced wide-body airliner.The power of civil aviation has made the Silk Road more convenient than ever before.Over the last decade of the Belt and Road Initiative(BRI),the“Aerial Silk Road”has connected more and more destinations around the world.
文摘The aim of this study was to verify the existence of business and strategic intelligence policies at the level of Congolese companies and at the state level, likely to foster progress and healthy development in the east of the DRC. The study was based on a mixed perspective consisting of objective analysis of quantitative data and interpretative analysis of qualitative data. The results showed that business and strategic intelligence policies have not been established at either company or state level, as this is an area of activity that is not known to the players in companies and public departments, and there are no units or offices in their organizational structures responsible for managing strategic information for competitiveness on the international market. In addition, there is a real need to establish strategic information management units within companies, upstream, and to set up a national strategic information management department or agency to help local companies compete in the marketplace, downstream. This reflects the importance and timeliness of building business and strategic intelligence policies to ensure economic progress and development in the eastern DRC. Business and strategic intelligence provides companies with an appropriate tool for researching, collecting, processing and disseminating information useful for decision-making among stakeholders, in order to cope with a crisis or competitive situation. The study suggests a number of key recommendations based on its findings. To the government, it is recommended to establish the national policy of business and strategic intelligence by setting up a national agency of strategic intelligence in favor of local companies;and to companies to establish business intelligence units in their organizational structures in favor of stakeholders to foster advantageous decision-making in the competitive market and achieve progress. Finally, the study suggests that studies be carried out to fully understand the opportunities and impact of business and strategic intelligence in African countries, particularly in the DRC.
基金supported by the National Key Technologies R&D Program of China[grant number 2022YFC3002803]the National Science Fund for Distinguished Young Scholars[grant number 41925021].
基金supported by the National Natural Science Foundation of China(Grant No.41972109)the Chengdu University of Technology Postgraduate Innovative Cultivation Program(CDUT2022BJCX004).
文摘There is great controversy regarding the origin and source of natural gas in the Lower Triassic Feix-ianguan Formation in the Eastern Sichuan Basin.This seriously restricts the study of natural gas dy-namics in the Feixianguan Formation and thus hampers natural gas exploration in the region,so further study is urgently required.Using experimental tests of natural gas composition,stable isotopes,and noble gas isotopes with gas chromatography(GC)and mass spectrometry(MS)studies of source rock and reservoir asphalt saturated hydrocarbons,the natural gas geochemical characteristics,the genetic identification and a gas-source comparison of the Feixianguan Formation were studied.Then,con-strained by the thermal history,the histories of gas generation and expulsion were restored by basin simulation technology.Finally,a gas accumulation model was established for the Feixianguan Formation.The results showed that(1)the H_(2)S-rich and H2S-poor gas reservoirs of the Feixianguan Formation are distributed on the east and west sides of the Kaijiang-Liangping trough in the Eastern Sichuan Basin,respectively.The carbon and hydrogen isotope compositions of the natural gas in the gas reservoirs are generally heavy and have typical characteristics of high-maturity dry gas reservoirs.(2)The natural gas of the Feixianguan Formation is organic thermogenic gas,which is mainly oil-type gas generated by the secondary cracking of crude oil.The gas-generating parent material is mainly type II kerogen.(3)The natural gas of the Feixianguan Formation in the Eastern Sichuan Basin was mainly generated by argil-laceous source rocks of the Upper Permian Longtan Formation.(4)Natural gas accumulation occurred as follows:the paleo-structure heights were filled with crude oil in the Early Jurassic,and paleo-oil res-ervoirs were formed in the Feixianguan Formation;during the Middle-Late Jurassic,the paleo-oil res-ervoirs were cracked when the reservoir temperatures rose above 160 C,and paleo-gas reservoirs were formed.Since the end of the Late Jurassic,the paleo-gas reservoirs have been adjusted and reformed to form the present-day natural gas reservoirs.These results provide a basis for studying natural gas accumulation dynamics of the Feixianguan Formation in the Eastern Sichuan Basin.
基金supported by the National Natural Science Foundation of China (Grant No. 41831175)the Fundamental Research Funds for the Central Universities (Grant No. B210201029)+2 种基金the Key Scientific and Technological Project of the Ministry of Water Resources, P. R. China (SKS2022001)the Joint Open Project of the KLME and CIC-FEMD (Grant No. KLME202202)the Open Research Fund of the State Key Laboratory of Tropical Oceanography (South China Sea Institute of Oceanology, Chinese Academy of Sciences) (Grant No. LTO2110)
文摘Seasonal prediction of summer precipitation over eastern China is closely linked to the East Asian monsoon circulation,which is largely affected by the El Niño-Southern Oscillation(ENSO).In this study,results show that spring soil moisture(SM)over the Indo-China peninsula(ICP)could be a reliable seasonal predictor for eastern China summer precipitation under non-ENSO conditions.When springtime SM anomalies are present over the ICP,they trigger a structured response in summertime precipitation over most of eastern China.The resultant south-to-north,tri-polar configuration of precipitation anomalies has a tendency to yield increased(decreased)precipitation in the Yangtze River basin and decreased(increased)in South and North China with a drier(wetter)spring soil condition in the ICP.The analyses show that ENSO exerts a powerful control on the East Asian circulation system in the ENSO-decaying summer.In the case of ENSO forcing,the seasonal predictability of the ICP spring SM for eastern China summer precipitation is suppressed.However,in the absence of the influence of ENSO sea surface temperature anomalies from the preceding winter,the SM anomalies over the ICP induce abnormal local heating and a consequent geopotential height response owing to its sustained control on local temperature,which could,in turn,lead to abnormal eastern China summer precipitation by affecting the East Asian summer monsoon circulation.The present findings provide a better understanding of the complexity of summer climate predictability over eastern China,which is of potential significance for improving the livelihood of the people.
基金The National Key Research and Development Program of China under contract No.2022YFE0140500the National Natural Science Foundation of China under contract Nos 41821004 and 42130406+2 种基金the National Natural Science Foundation of China-Shandong Joint Fund under contract No.U1906215the Open Fund of Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences under contract No.KLOCW2003the Project of Doctoral Found of Qingdao University of Science and Technology under contract No.210010022746.
文摘As important atmospheric circulation patterns in Northern Hemisphere(NH),the North Atlantic Oscillation(NAO)and the Western Pacific teleconnection(WP)affect the winter climate in Eurasia.In order to explore the combined effects of NAO and WP on East Asian(EA)temperature,the NAO and WP indices are divided into four phases from 1980−2021:the positive NAO and WP phase(NAO+/WP+),the negative NAO and WP phase(NAO−/WP−),the positive NAO and negative WP phase(NAO+/WP−),the negative NAO and positive WP phase(NAO−/WP+).In the phase of NAO+/WP+,the low geopotential height(GH)stays in north of EA at 50°−80°N;the surface air temperature anomaly(SATA)is 0.8−1℃lower than Southern Asian.In the phase of NAO−/WP−,the center of high temperature and GH locate in the northeast of EA;the cold air spreads to Southern Asia,causing the SATA decreases 1−1.5℃.In the phase of NAO+/WP−,the high GH belt is formed at 55°−80°N.Meanwhile,the center of high SATA locates in the north of Asia that increases 0.8−1.1℃.The cold airflow causes temperature dropping 0.5−1℃in the south of EA.The SATA improves 0.5−1.5℃in south of EA in the phase of NAO−/WP+.The belt of high GH is formed at 25°−50°N,and blocks the cold air which from Siberia.The NAO and WP generate two warped plate pressure structures in NH,and affect the temperature by different pressure configurations.NAO and WP form different GH,and GH acts to block and push airflow by affecting the air pressure,then causes the temperature to be different from the north and south of EA.Finally,the multiple linear regression result shows that NAO and WP are weakened by each other such as the phase of NAO+/WP+and NAO−/WP−.
文摘The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.
基金Under the auspices of National Natural Science Foundation of China(No.42171211,41971215,41901215,41771193)。
文摘The continuous development of agricultural technologies and produces trade and updated state reforms strongly shape the dominant organizing styles of local agriculture production.Since the end of the 1970s,rural China has witnessed a drastic agriculture transformation featured by de-collectivization,and recently in Taicang,a developed city in the eastern China,a kind of new cooperative farms have replaced the smallholders by pooling households’contracted farmland,signaling a new shift tendency towards agriculture recollectivization that is distinctive compared to other countries.Given the state governance’s leadership in promoting this latest transformation,drawing on the theoretical concept of‘governmentality’that is powerful in understanding how to govern the society to meet certain objectives,this paper examines the accurate processes of agriculture re-collectivization in Taicang City based on the methods of semi-structured interview and participant observation.Our research shows that the China’s tax-sharing and relevant reforms in the 1990s framed a new governance structure in line with the new mode of‘governmentality’closely linked to‘advanced liberalism’,creating the responsibility shift from central to local governments and a set of evaluation technologies,and guiding various actors to engage in the agriculture re-collectivization practice in Taicang.Importantly,the considerable subsidies and the impressive extension services in terms of farming personnel training and agricultural techniques diffusion underpin the normal running of cooperative farms and contribute to the local implementation of national strategy of agriculture modernization.We argue that the combination of distinctive institutional arrangement of rural land owned by village collectives in China and the burgeoning local economy allows the developed areas to re-collectivizing the agriculture production for ensuring grain self-sufficiency rather than capturing more share in global agriculture products trade,and that the cooperative farms in our case have been deeply integrated into the‘modern procurement system’and become more sensitive to market fluctuation,requiring rural extension service to transform towards farms’capacity building for maintaining the longterm development momentum.
文摘Introduction: Pregnancy resulting from rape is a public health and sexual and reproductive health issue, especially among minors. Rape can be perpetrated with or without physical restraint. The objective of the present study is to highlight the prevalence of physical coercion leading to pregnancy and the associated maternal-fetal complications. Methodology: This was a comparative descriptive and analytical cross-sectional study of complications associated with post-rape pregnancy by physical restraint among minors who were treated at the General Reference Hospital of Panzi over a two-year period from June 2020 to June 2022. A total of 140 minor survivors of violence with pregnancy were included in the study. Data were collected using a questionnaire, coded and analyzed in Excel and XLSTAT version 2014. Results: The prevalence of physical constraints was 65%. After mulltivariate analyses, denial of pregnancy (ORa: 9.64 95% CI: 1.1 - 81.2;p-value: 0.0370), attempted abortion (ORa: 56.1 95% CI: 1.5 - 2027.6;p-value: 0.0278) and agitation during delivery (ORa: 88.7 95% CI: 4.5 - 1715;p-value: 0.0030) were the complications associated with pregnancy in minors who experienced physical restraint rape. In addition, BMI was a factor in reducing the risk of physical restraint rape at the ORa of 0.5054 [0.3;0.8];p 0.006). Conclusion: Pregnancy among minors is a reality and occurs in a situation of physical coercion in the eastern Democratic Republic of Congo. These pregnancies are often associated with complications that require an intensive management system since they can jeopardize the maternal-fetal prognosis of minors.
文摘We have been pleased that our paper Geological mapping and mining prospecting in the Aouli inlier(Eastern Meseta,Morocco) based on remote sensing and geographic information systems(GIS) was of interest to our colleagues who commented it in China Geology 5(2022) 1–4.
基金National Key Research and Development Program of China (2021YFC3000802)National Natural Science Foundation of China (41875059)The Open Research Program of the State Key Laboratory of Severe Weather (2021LASW-A04)。
文摘This study examines the spatio-temporal characteristics of heavy precipitation forecasts in eastern China from the European Centre for Medium-Range Weather Forecasts(ECMWF) using the time-domain version of the Method for Object-based Diagnostic Evaluation(MODE-TD). A total of 23 heavy rainfall cases occurring between 2018 and 2021 are selected for analysis. Using Typhoon “Rumbia” as a case study, the paper illustrates how the MODE-TD method assesses the overall simulation capability of models for the life history of precipitation systems. The results of multiple tests with different parameter configurations reveal that the model underestimates the number of objects’ forecasted precipitation tracks, particularly at smaller radii. Additionally, the analysis based on centroid offset and area ratio tests for different classified precipitation objects indicates that the model performs better in predicting large-area, fast-moving, and longlifespan precipitation objects. Conversely, it tends to have less accurate predictions for small-area, slow-moving, and shortlifespan precipitation objects. In terms of temporal characteristics, the model overestimates the forecasted movement speed for precipitation objects with small-area, slow movement, or both long and short lifespans while underestimating it for precipitation with fast movement. In terms of temporal characteristics, the model tends to overestimate the forecasted movement speed for precipitation objects with small-area, slow movement, or both long and short lifespans while underestimating it for precipitation with fast movement. Overall, the model provides more accurate predictions for the duration and dissipation of precipitation objects with large-area or long-lifespan(such as typhoon precipitation) while having large prediction errors for precipitation objects with small-area or short-lifespan. Furthermore, the model’s simulation results regarding the generation of precipitation objects show that it performs relatively well in simulating the generation of large-area and fast-moving precipitation objects. However, there are significant differences in the forecasted generation of small-area and slow-moving precipitation objects after 9 hours.
文摘Medicinal plants play a major role in meeting people’s medical and health needs, especially in developing countries. However, due to a lack of access to modern veterinary facilities, poor visibility of animal health personnel, and high prices of orthodox medicines, most farmers rely on traditional healers and the administration of medicinal plants to treat livestock ailments. The present study was conducted to document Ethnopharmacological knowledge of medicinal plants used to manage livestock ailments in three rural communities of the Eastern Cape. This study was carried out in three rural communities between July 2009 and February 2010. Data were collected by administering pre-tested semi-structured questionnaires and participative field observations. For the interviews, a sample of 48 knowledgeable respondents was purposively selected. Data were analyzed using descriptive and inferential statistics, determination of information consensus factor, and fidelity level. A total of 12 medicinal plants belonging to 9 families were used by local people to cure different ailments. A high number of medicinal plants were claimed by males compared to females. Roots and barks were the major plant parts used, and the least were leaves (27.3%). Six plants were used to treat diarrhea and fertility, five plants to treat wounds, and two plants to treat scabs. This study has shown that Eastern Cape flora is rich with various plants which could be used to replace orthodox drugs. Further studies are needed to determine the minimum inhibitory concentrations, biological activities, and toxicities and characterize the plant’s chemical compounds.
基金Supported by the PetroChina Science and Technology Innovation Fund Project(2021DQ02-1003)Basic Research Project for Central Universities(2022JCCXDC02).
文摘Through core observation,thin section identification,X-ray diffraction analysis,scanning electron microscopy,and low-temperature nitrogen adsorption and isothermal adsorption experiments,the lithology and pore characteristics of the Upper Carboniferous bauxite series in eastern Ordos Basin were analyzed to reveal the formation and evolution process of the bauxite reservoirs.A petrological nomenclature and classification scheme for bauxitic rocks based on three units(aluminum hydroxides,iron minerals and clay minerals)is proposed.It is found that bauxitic mudstone is in the form of dense massive and clastic structures,while the(clayey)bauxite is of dense massive,pisolite,oolite,porous soil and clastic structures.Both bauxitic mudstone and bauxite reservoirs develop dissolution pores,intercrystalline pores,and microfractures as the dominant gas storage space,with the porosity less than 10% and mesopores in dominance.The bauxite series in the North China Craton can be divided into five sections,i.e.,ferrilite(Shanxi-style iron ore,section A),bauxitic mudstone(section B),bauxite(section C),bauxite mudstone(debris-containing,section D)and dark mudstone-coal section(section E).The burrow/funnel filling,lenticular,layered/massive bauxite deposits occur separately in the karst platforms,gentle slopes and low-lying areas.The karst platforms and gentle slopes are conducive to surface water leaching,with strong karstification,well-developed pores,large reservoir thickness and good physical properties,but poor strata continuity.The low-lying areas have poor physical properties but relatively continuous and stable reservoirs.The gas enrichment in bauxites is jointly controlled by source rock,reservoir rock and fractures.This recognition provides geological basis for the exploration and development of natural gas in the Upper Carboniferous in the study area and similar bauxite systems.
基金The study has received support from the National Natural Science Foundation of China(No.41906182)the National Program on Global Change and Air-Sea Interactions(No.GASI-01-WIND-STwin)the Program of Shandong Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation(Nos.202102,202209 and 201901).
文摘Colored dissolved organic matter(CDOM)is a crucial constituent that affects the optical absorption properties of seawater.Owing to the relatively limited measured data on the spatial distribution characteristics of CDOM in the tropical eastern Indian Ocean,this study analyzes the optical absorption characteristics of CDOM in the southeast Indian Ocean using the data collected during four seasons from 2013 to 2017.This work also systematically describes the seasonal horizontal and vertical distribution characteristics of CDOM in this area and conducts a preliminary analysis of the relevant factors affecting CDOM absorption characteristics in this region.Results indicate that the CDOM ag(440)during summer was remarkably lower than that in the coastal waters of Europe and coastal waters of China but slightly higher than that in the western and southeast Pacific.The spatial distribution of surface CDOM shows remarkable seasonal differences,and the spatial distribution characteristics of CDOM in the 5°S,92°E region differ between spring/summer and autumn/winter.The values of ag(400)and ag(440)are weak/strong at a surface/subsurface level of 100 m,with differences found between summer and winter.The correlation of CDOM with temperature,salinity,and chlorophyll-a concentration is relatively low,indicating that CDOM is an independent driving mechanism influenced by phytoplankton degradation,photobleaching,and water mixing.
文摘Aptian is characterized by widespread deposition of organic-rich sediment.The Aptian bitumen limestone horizon,which is thin decimetre-thick sequences,locally crops out in the Kircaova area,Eastern Black Sea Region(Eastern Pontides).They are well correlated with Aptian bitumen limestone in the other Tethys Reams.They are proposed as episodes of increased organic matter.However,background factors controlling organic matter enrichment are poorly known.In this study,we present new inorganic geochemistry,including trace elements,rare earth elements(REE),redox-sensitive elements(RSE),stable-isotopes(δ~(18)O andδ~(13)C),and total organic carbon(TOC).We integrated new geochemical data with existing stratigraphy,paleontology,and organic chemistry data to provide new insight into the depositional environment and paleoclimate conditions during Aptian.The lacustrine bitumen limestone(LBL)samples have variedδ~(13)C(ave.-1.45‰)andδ~(18)O(ave.-4.50‰).They possess distinct REE patterns,with an average of REE(ave.14.45 ppm)and Y/Ho(ave.35)ratios.In addition,they have variable Nd/YbN(0.28-0.81;ave.0.56)and Ce/Ce*(0.68-0.97;ave.0.86),and relatively high Eu^(*)/Eu(1.23-1.53;ave.1.35).They display seawater signatures with reduced oxygen conditions.The enrichment in RSE(Mo,Cu,Ni,and Zn)and the low Mo/TOC(0.70-3.69;ave.2.41)support a certain degree of water restriction.The high Sr/Ba,Sr/Cu,Ga/Rb,and K/Al records of the LBL facies suggest hot house climatic conditions.The sedimentary environment was probably an isolated basin that is transformed from the marine basin.In addition to depositional conditions,the regional parameters such as the climate,increased run-off period,nutrient levels,alkalinity level,and dominant carbonate producers favored the enrichment in organic matter of LBL facies.Thus,extreme greenhouse palaeoclimate conditions have an important role in organic matter enrichment in the isolated basin.Our results are conformable with the published data from marine,semi-restricted basin,and lacustrine settings in the different parts of the Tethys margin.Thus,this approach provides the first insight into the Aptian greenhouse paleo-climate conditions of the Eastern Black Sea Region,NE Turkey.