Centuries-Old Villages in Southern Anhui:Xidi and Hongcun

Xidi and Hongcun are two of the most representative ancient villages in the southern part of Anhui Province.Dating back to the Song Dynasty,they still preserve hundreds of residential buildings from the Ming and Qing Dynasties.

Retinal capillary density among healthy Egyptian and South Asian students:an optical coherence tomography angiography study

AIM:To compare the macular and optic nerve perfusion and vascular architecture using optical coherence tomography angiography(OCTA)in normal eyes of Egyptian(Caucasians)and South Asian(Asians)volunteers.METHODS:Cross-sectional analytical OCTA study performed on 90 eyes of South Asian(n=45)and Egyptians(n=45)were analyzed.All participants underwent bestcorrected visual acuity test,slit lamp,and fundus examination.OCTA images;macular 6×6 mm^(2) grid and optic nerve 4.5×4.5 mm^(2) grid were used to examine the parafoveal and peripapillary regions,respectively.RESULTS:The mean capillary vessel density(CVD)in macular sectors among South Asians and Egyptians participants were(50.31%±2.53%,51.2%±5.93%)and(49.71%±3.6%,51.94%±4.79%)in superficial(SCP)and deep capillary plexuses(DCP),respectively(P>0.05).Mean CVD in both groups was higher in DCP compared to SCP in all sectors but was not significant(P>0.05).Mean foveal CVD increases with an increase in central retinal thickness in both SCP and DCP(P<0.001),among both groups.Mean area of the foveal avascular zone(FAZ)was 0.28±0.09 and 0.27±0.08 mm2 in South Asian and Egyptians,respectively.FAZ area decreases with an increase in the thickness and foveal CVD(P<0.001).Mean CVD in the peripapillary area was 48.23%±5.78% in South Asian and 49.52%±2.38% in Egyptian volunteers.The mean retinal nerve fiber layer thickness was found to be higher in the nasal quadrant among South Asian females than the Egyptian females(P<0.05).CONCLUSION:No significant racial disparity is found in this study.The findings are helpful for assessing and improving the normative data on the differences in South Asian and Egyptian populations.

Subsurface Temperature and Salinity Structures Inversion Using a Stacking-Based Fusion Model from Satellite Observations in the South China Sea

Three-dimensional ocean subsurface temperature and salinity structures(OST/OSS)in the South China Sea(SCS)play crucial roles in oceanic climate research and disaster mitigation.Traditionally,real-time OST and OSS are mainly obtained through in-situ ocean observations and simulation by ocean circulation models,which are usually challenging and costly.Recently,dynamical,statistical,or machine learning models have been proposed to invert the OST/OSS from sea surface information;however,these models mainly focused on the inversion of monthly OST and OSS.To address this issue,we apply clustering algorithms and employ a stacking strategy to ensemble three models(XGBoost,Random Forest,and LightGBM)to invert the real-time OST/OSS based on satellite-derived data and the Argo dataset.Subsequently,a fusion of temperature and salinity is employed to reconstruct OST and OSS.In the validation dataset,the depth-averaged Correlation(Corr)of the estimated OST(OSS)is 0.919(0.83),and the average Root-Mean-Square Error(RMSE)is0.639°C(0.087 psu),with a depth-averaged coefficient of determination(R~2)of 0.84(0.68).Notably,at the thermocline where the base models exhibit their maximum error,the stacking-based fusion model exhibited significant performance enhancement,with a maximum enhancement in OST and OSS inversion exceeding 10%.We further found that the estimated OST and OSS exhibit good agreement with the HYbrid Coordinate Ocean Model(HYCOM)data and BOA_Argo dataset during the passage of a mesoscale eddy.This study shows that the proposed model can effectively invert the real-time OST and OSS,potentially enhancing the understanding of multi-scale oceanic processes in the SCS.

Carboniferous-Early Permian heterogeneous distribution of porous carbonate reservoirs in the Central Uplift of the South Yellow Sea Basin and its hydrocarbon potential analysis

Mesozoic-Palaeozoic marine carbonate rocks are crucial hydrocarbon reservoirs in the Central Uplift area of the South Yellow Sea Basin(SYSB).Due to the scarcity of boreholes and the significant heterogeneity of carbonate reservoirs,the distribution of porous carbonate reservoirs and their related key controlling factors remain unclear.In this study,factors affecting the distribution of porous Carboniferous-Early Permian carbonate reservoirs in the SYSB were investigated through seismic inversion and isotope analysis.The log-seismic characteristics of porous carbonate reservoirs,sensitive lithology parameters,and physical property parameters were extracted and analyzed.The pre-stack simultaneous inversion technique was applied to predict the lithology and physical properties of porous carbonate reservoirs.Moreover,the sedimentary of carbonate was analyzed using isotopes of carbon,oxygen,and strontium.The results show that porous carbonate reservoirs are mainly developed in the open platform sediments with porosities of 3%-5%and are mainly distributed in the paleo-highland(Huanglong Formation and Chuanshan Formation)and the slope of paleo-highland(Hezhou Formation).The porous carbonate reservoirs of the Qixia Formation are only locally developed.In addition,the negativeδ13C excursions indicate a warm and humid tropical climate with three sea-level fluctuations in the study area from the Carboniferous to Early Permian.The favorable conditions for developing porous carbonate rocks include the sedimentary environment and diagenetic process.The primary pore tends to form in high-energy environments of the paleo-highland,and the secondary pore is increased by dissolution during the syngenetic or quasi-syngenetic period.According to the hydrocarbon potential analysis,the Late Ordovician Wufeng Formation and Lower Silurian Gaojiabian Formation are the source rocks in the high-maturity-over-maturity stage,the Carboniferous-Lower Permian carbonate is the good reservoirs,and the Late Permian Longtan-Dalong Formation is the stable seal,ensuring a huge hydrocarbon accumulation potential in SYSB.The methods proposed in this study can be applied to other carbonate-dominated strata worldwide.

Roles and Functions of Tourism Destinations in Tourism Region of South Anhui:A Tourist Flow Network Perspective

Theoretic and practical significance has been highlighted in the research of the roles and functions of destinations,as destinations are restricted by the spatial structure based on tourist flow network from the perspective of relationship.This article conducted an empirical analysis for Tourism Region of South Anhui(TRSA) and revealed the necessity and feasibility of studying the roles and functions of destinations from tourist flow network's perspective.The automorphic equivalence analysis and centrality analysis were used to classify 16 destinations in TRSA into six role types:tourist flow distribution center,hub of tourist flows,passageway destination,common touring destination,attached touring destination,and nearly isolated destination.Some suggestions were given on suitable infrastructure construction and destinations service designs according to their functions in network.This destination role positioning was based on tourist flow network structure in integral and macroscopic way.It provided an important reference for the balanced and harmonious development of all the destinations of TRSA.In addition,this article verified the applicability of social network analysis on tourist flow research in local scale,and expanded this method to destination role and function positioning.

Geochemistry of Rare Earth Elements in Xikeng Ag-Pb-Zn Ore Deposit, South Anhui, China

In this paper, a comparative study is done on the geochemical charateristics of REE in ore, ore-hosted rocks of Lantian group, granite related to ore deposit, and altered rocks for tracing origin of ore-forming materials. The result indicates that the ore-forming fluid and ore-forming materials for Xikeng silver-polymetallic ore deposit were derived from Yixian granite's magmatic activity. Water-rock reaction of the hydrothermal fluid with the carbonate-rich stratum led the altered rock to relatively enrich in HREE.

Geochemistry and geochronology of Late Jurassic and Early Cretaceous intrusions related to some Au(Sb) deposits in southern Anhui: a case study and review

Some Au deposits in southern Anhui Province have recently been found to be closely associated with Late Mesozoic intrusions. Typical examples include the Huashan Au(Sb) deposit and Au deposits at Zhaojialing, Wuxi,and Liaojia. In order to understand the mechanisms that led the formation of these Au deposits, we make detailed reviews on the geological characteristics of these Au deposits. Specifically, we present new LA-ICP-MS zircon U–Pb dating, along with elemental and Hf isotopic data from the Huashan Au(Sb) deposit. Our data suggests that the Huashan ore-related intrusions were emplaced during the Late Jurassic and Early Cretaceous periods(144–148 Ma). They are characterized by arc-magma features and high oxygen fugacity and are rich in inherited zircons. Zircon U–Pb ages and Lu–Hf isotopes from intrusions suggest that Proterozoic juvenile lithosphere is the main source of these intrusions. The regional geological history implies that lithosphere beneath southern Anhui was produced during a Proterozoic subduction and was fertilized with Au(Cu) in the process. Integrated with theresults of previous studies, we inferred that Late Mesozoic intrusions formed by the remelting of the lithosphere could provide the metal endowment for the Au-rich deposits in southern Anhui.

Hamatophyton from the Late Devonian of Anhui Province,South China and Evolution of Sphenophyllales

Well-preserved specimens of Hamatophyton verticillatum collected from the Upper Devonian （Famennian） Wutong Formation of Chaohu district, Anhui Province, South China, display more complete fertile axes in three orders and multiple divisions. Comparisons indicate that Hamatophyton possibly does not have palmate planate sterile leaves but hook-like linear ones with rare divisions. We propose seven definitive characters of Sphenophyllales： （1） completely whorled lateral organs; （2） sterile leaves; （3） strobili; （4） ＂sporangiophores＂ or stalks with reflexed tips bearing sporangia; （5） three- or four-ribbed primary xylem; （6） exarch maturation of primary xylem; and （7） secondary xylem. The Sphenophyllales probably originated from the Iridopteridales based on similarities in whorled lateral organs, ribbed primary xylem and peripheral protoxylem strands. In transition from Iridopteridales to Sphenophyllales, morphological changes involve partially whorled to completely whorled lateral organs, sterile ultimate appendages to leaves, and fertile ultimate appendages to ＂sporangiophores＂/stalks with bracts; anatomical modifications include configuration and maturation of primary xylem, and presence of secondary xylem.

Study on the Sustainable Development of the Tobacco-growing Area in South Anhui

Based on the actual situation of tobacco production in South Anhui tobacco-growing area,the paper analyzes several major constraints,and discusses several aspects such as tobacco production human resources,production of large-scale cultivation,science and technology service providers,the standardized production management and production security system. The countermeasures and suggestions for sustainable development are also put forward to provide a reference for the sustainable development of tobacco-growing area in South Anhui.

Foreign-funded“Double Excellence Enterprise”——Anhui South Textile Co.Ltd.

The Anhui South Textile Co.Ltd.,established in September 1992,is a Sino-foreign cooperative enterprise,stock-held by Anqing TextileFactory.It has a total investment of RMB 16.5 million,registered capitalof RMB 11.55 million,with 25.3 percent shared by the foreign side.Mainproducts include combed yarn under 100s. Since its operation,the company,by making full use of its advantages—having an annual export quota for cotton yarn of 9000 pieces,preferential policy,new equipment,strong ability for high grade

A Preliminary Study on Botanical Pesticide Resources in Southwest Anhui Province

With the improvement of living standards, people have paid more and more attention to the use of agricultural products, and botanical pesticides are favored due to low residue and environmental safety. There are abundant vegetations in southwest Anhui Province, but many insecticidal plants have not been developed into botanical pesticides. The author expounded the research status of botanical pesticides, and summarized botanical pesticide resources in southwest Anhui Province, in order to provide a reference for the development of new botanical pesticides.

Late Triassic Intracontinental Deformation of South Tianshan,Central Asia:Evidence from Syn-tectonic Sedimentation and Detrital Zircon Provenances of the Kuqa Depression

The Tianshan range,a Paleozoic orogenic belt in Central Asia,has undergone multiple phases of tectonic activities characterized by the N-S compression after the early Mesozoic,including the far-field effects of the Cenozoic Indian-Asian collision.However,there are limited reports on the tectonic deformation and initiation of Triassic intracontinental deformation in the Tianshan range.Understanding this structural context is crucial for interpreting the early intracontinental deformation history of the Eurasian continent during the early Mesozoic.Growth strata and syn-tectonic sediments provide a rich source of information on tectonic activities and have been extensively used in the studies of orogenic belts.Based on detail fieldwork conducted in this study,the middle-late Triassic Kelamayi Formation of the northern Kuqa Depression in the southern Tianshan fold-thrust belt has been identified as the typical syn-tectonic growth strata.The youngest detrital zircon component in two lithic sandstone samples from the bottom and top of the Kelamayi growth strata yielded U-Pb ages of 223.4±3.1 and 215.5±2.9 Ma,respectively,indicating that the maximum depositional age of the bottom and top of the Kelamayi growth strata is 226-220 and 218-212 Ma.The geochronological distribution of detrital samples from the Early-Middle Triassic and Late Triassic revealed abrupt changes,suggesting a new source supply resulting from tectonic activation in the Tianshan range.The coupling relationship between the syn-tectonic sedimentation of the Kelamayi Formation and the South Tianshan fold-thrust system provides robust evidence that the Triassic intracontinental deformation of the South Tianshan range began at approximately 226-220 Ma(during the Late Triassic)and ended at approximately 218-212 Ma.These findings provide crucial constraints for understanding the intraplate deformation in the Tianshan range during the Triassic.

Impacts of Future Changes in Heavy Precipitation and Extreme Drought on the Economy over South China and Indochina

Heavy precipitation and extreme drought have caused severe economic losses over South China and Indochina(INCSC)in recent decades.Given the areas with large gross domestic product(GDP)in the INCSC region are distributed along the coastline and greatly affected by global warming,understanding the possible economic impacts induced by future changes in the maximum consecutive 5-day precipitation(RX5day)and the maximum consecutive dry days(CDD)is critical for adaptation planning in this region.Based on the latest data released by phase 6 of the Coupled Model Intercomparison Project(CMIP6),future projections of precipitation extremes with bias correction and their impacts on GDP over the INCSC region under the fossil-fueled development Shared Socioeconomic Pathway(SSP5-8.5)are investigated.Results indicate that RX5day will intensify robustly throughout the INCSC region,while CDD will lengthen in most regions under global warming.The changes in climate consistently dominate the effect on GDP over the INCSC region,rather than the change of GDP.If only considering the effect of climate change on GDP,the changes in precipitation extremes bring a larger impact on the economy in the future to the provinces of Hunan,Jiangxi,Fujian,Guangdong,and Hainan in South China,as well as the Malay Peninsula and southern Cambodia in Indochina.Thus,timely regional adaptation strategies are urgent for these regions.Moreover,from the sub-regional average viewpoint,over two thirds of CMIP6 models agree that maintaining a lower global warming level will reduce the economic impacts from heavy precipitation over the INCSC region.

A new molar from the Middle Pleistocene hominid assemblage of Yanhuidong, Tongzi, South China

1988年,贵州省博物馆对桐梓岩灰洞的支洞进行了最后一次发掘。2014年,在洞内第四层堆积物中鉴定出逾2000件的动物牙齿化石,以及一枚古人类上颊齿(编号:TZ-1)。1991年,铀系法测定这些次生堆积物的沉积年代约为距今24万年。本文运用高精度CT(巴黎自然历史博物馆)对TZ-1的釉质齿质界面(EDJ)和牙髓腔几何形态进行了分析。TZ-1的冠面形态有如下特征:次尖小且在远中舌侧不发育,咀嚼面轮廓呈四边形,颊舌径稍大过近中远中径,原尖舌侧齿带发育,齿尖从大到小依次为原尖、后尖、前尖和次尖。TZ-1牙髓腔的髓角与其釉质齿质界面以及釉质表面的形态都具有相关性。TZ-1的形态与M1虽有相似之处,但完全不同于1983年出土于同一层位的另两颗M1;其应被鉴定为dm2,并可被归入中中更新世的中国直立人支系。岩灰洞上臼齿PA 875的形态与建始龙骨洞PA 1279和周口店直立人等古老型直立人相似。岩灰洞另一枚刚萌发的臼齿PA 874具有凸出的次尖和长菱形的外廓,接近于爪哇型直立人Sangiran NG 91-G10;这也是智人和尼安德特人的共有衍征。但PA 874的冠面仍保留了亚洲型的齿带,因而被归入人属未定种。因出土自次生堆积,岩灰洞的三种古人类类型未必曾同时并存,但却揭示了华南地区人类演化进程中的多样面貌。

Geochemical prerequisites for the formation of oil and gas accumulation zones in the South Turgay basin,Kazakhstan

This study predicts favorable oil and gas source-rock formation conditions in the Aryskum Depression of the South Turgay Basin,Kazakhstan.This study assesses the thermal maturity and characteristics of organic matter by determining its environmental conditions using data from geochemical analysis of core(pyrolysis)and oil(biomarkers and carbon isotopic compositions)samples.According to the geochemical parameters obtained by pyrolysis,the oil generation potential of the original rocks of most studied samples varies from poor to rich.The facies–genetic organic matter is predominantly humic and less frequently humus–sapropel,indicating organic matter accumulation in the studied samples were under moderately reducing conditions(kerogenⅢand Ⅱ types)and coastal–marine environments(kerogen typeⅠ).The carbon isotopic compositions of oils derived from the Jurassic deposits of the Aryskum Depression also indicate the sapropelic and mixed humic–sapropelic type of organic matter(kerogenⅡandⅠ).Biomarker analysis of oils indicates original organic matter formation in an anoxic environment.

VARIATION IN FLOW AND SEDIMENT OF DASHA RIVER AND INFLUENCE OF HUMAN ACTIVITIES ON IT IN SOUTHWEST REGION OF ANHUI PROVINCE

Soil and water loss is now a major environmental problem in many areas of China, especially in the area of the Dabie Mountain, Anhui Province, which results in environmental degradation and does harm to the people＇s life and production there. Based on the observational records from the Dasha River, the authors analyze the character of the variation in flow and sediment in different flood and dry seasons from 1970 to 2000. The result shows that human activities had significantly reduced the sediment discharge and sediment module, and increased the runoff in low-water seasons since the 1980s. The average contribution rate ofhnman activities to decreasing sediment was 65.67%, and at the same period the contribution rate of runoff and rainfall was about 34.33%. Therefore, it is necessary to take the biological and engineering measures to solve the problem of soil and water loss in the Dasha River watershed.

Deep-large faults controlling on the distribution of the venting gas hydrate system in the middle of the Qiongdongnan Basin, South China Sea

Many locations with concentrated hydrates at vents have confirmed the presence of abundant thermogenic gas in the middle of the Qiongdongnan Basin(QDNB).However,the impact of deep structures on gasbearing fluids migration and gas hydrates distribution in tectonically inactive regions is still unclear.In this study,the authors apply high-resolution 3D seismic and logging while drilling(LWD)data from the middle of the QDNB to investigate the influence of deep-large faults on gas chimneys and preferred gasescape pipes.The findings reveal the following:(1)Two significant deep-large faults,F1 and F2,developed on the edge of the Songnan Low Uplift,control the dominant migration of thermogenic hydrocarbons and determine the initial locations of gas chimneys.(2)The formation of gas chimneys is likely related to fault activation and reactivation.Gas chimney 1 is primarily arises from convergent fluid migration resulting from the intersection of the two faults,while the gas chimney 2 benefits from a steeper fault plane and shorter migration distance of fault F2.(3)Most gas-escape pipes are situated near the apex of the two faults.Their reactivations facilitate free gas flow into the GHSZ and contribute to the formation of fracture‐filling hydrates.

Coral records of Mid-Holocene sea-level highstands and climate responses in the northern South China Sea

High-resolution sea-level data and high-precision dating of corals in the northern South China Sea(SCS)during the Holocene provide a reference and historical background for current and future sea-level changes and a basis for scientific assessment of the evolutionary trend of coral reefs in the SCS.Although sporadic studies have been performed around Hainan Island in the northern SCS,the reconstructed sea level presents different values or is controversial because the indicative meaning of the sea-level indicators were neither quantified nor uniform criteria.Here,we determined the quantitative relationship between modern living coral and sea level by measuring the top surfaces of 27 live Porites corals from the inner reef flat along the east coast of Hainan Island and assessed the accuracy of results obtained using coral as sea-level indicators.Additionally,three in situ fossil Porites corals were analyzed based on elevation measurements,digital X-ray radiography,and U-Th dating.The survey results showed that the indicative meanings for the modern live Porites corals is(146.09±8.35)cm below the mean tide level(MTL).It suggested that their upward growth limit is constrained by the sea level,and the lowest low water is the highest level of survival for the modern live Porites corals.Based on the newly defined indicative meanings,6 new sea-level index points(SLIPs)were obtained and 19 published SLIPs were recalculated.Those SLIPs indicated a relative sea level fluctuation between(227.7±9.8)cm to(154.88±9.8)cm MTL between(5393±25)cal a BP and(3390±12)cal a BP,providing evidences of the Mid-Holocene sea-level highstand in the northern SCS.Besides that,our analysis demonstrated that different sea-level histories may be produced based on different indicative meanings or criteria.The dataset of 276 coral U-Th ages indicates that coral reef development in the northern SCS comprised the initial development,boom growth,decline,and flourishing development again.A comparison with regional records indicated that synergistic effects of climatic and environmental factors were involved in the development of coral reefs in the northern SCS.Thus,the cessation of coral reef development during the Holocene in the northern SCS was probably associated with the dry and cold climate in South China,as reflected in the synchronous weakening of the ENSO and East Asian summer monsoon induced by the reduction of the 65°N summer insolation,which forced the migration of the Intertropical Convergence Zone.

The Late Proterozoic Trench-Basin-Arc System in the Northeastern Jiangxi-Southern Anhui Region

Proterozoic rocks in the northeastern Jiangxi-southern Anhui may fall into three rock associations whichbelong to different but interrelated tectono-palaeogeographic units. The field geological and petrochemicalcharacteristics of the northeastern Jiangxi-western Zhejiang volcanic zone indicate that it was once an islandarc zone. An analysis of the sedimentary characteristics of Proterozoic turbidites lying north of the zone has re-vealed the history of development of a back-arc basin. According to the type of the Proterozoic rock formationsouth of the zone, it may be deduced that the formation might represent the fore-arc and trench areas. Bymeans of various tectono-palaeogeographic analyses, the relation between the island arc zone and the back-arcbasin is inferred and the Late Proterozoic tectono-palaeogeographic development is discussed by using themodel of the trench-arc-basin system.

Study on the Activity of the Toupo Fault in Southern Anhui Province

The Toupo Fault, located in southern Anhui Province, strikes N60°～70°E in a linear route that is clear on satellitic image. It plays an important role in controlling the tectonics, geomorphology and distribution of Mesozoic-Cenozoic basins and strata. Detailed field investigation was carried out along the Toupo Fault to study its activity. Profiles, as well as a trench excavated reveal that the Quaternary super stratum above the fault had not been offset. The stratum was sampled and dated with TL methods to be the Mid-Pleistocene time, implying that the fault had been no longer active since then. Three stages can be divided since the fault was formed. The first stage is in the late Yanshan Movement, when the fault movement was of reversal strike-slipping and the tracks formed then are still clear today. The second stage is in the early Himalayan Movement—the late Cretaceous-early Tertiary, when the fault movement turned to be normal faulting and the southern wall became a tensile basin and received clastic sediment. The third stage is since the late Tertiary, when the tectonic movement was very weak. No late Tertiary sediments were formed and the Quaternary sediment was only as thick as ten meters. The geomorphology also suggested an aging form. Neither vertical nor horizontal displacement was evident along the Toupo Fault during this stage, though fault gouge dating suggested that the Toupo Fault might have been active during the Mid-Pleistocene.