The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present ...The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present new cosmogenic nuclide isochron burial ages for the fifth(T5)and fourth(T4)terraces,yielding ages of 0.49±0.05 Ma and 0.35±0.04 Ma,respectively.By integrating our data with existing 14C and ESR ages for lower terraces,we reconstruct a detailed incision history,showing~85 m of river downcutting since the Middle Pleistocene.Incision rates varied over time,with a notable acceleration after 0.1 Ma coinciding with the Gonghe movement of the Tibetan Plateau,highlighting the role of tectonic uplift in driving fluvial incision.The formation of the fifth terrace is associated with the Kunlun–Huanghe uplift,while the development of the fourth terrace corresponds to the phase of regional uplift in the Qinling Mountains.Sedimentological evidence further indicates that terrace formation was influenced by both climatic and tectonic controls:while T4 aggraded during a glacial period,T5 formed during the interglacial MIS 13 under strong monsoonal conditions—demonstrating that major aggradation can occur during warm phases.However,sustained incision required tectonic forcing,as climatic transitions alone were insufficient to drive deep bedrock erosion.Our results also constrain the longdebated integration of the Three Gorges.The 0.49 Ma age for T5 provides a robust minimum age for the hydrological connection between the Sichuan and Jianghan Basins.This timing,combined with the earlier formation of the"First Bend of the Yangtze"(Eocene–Miocene),contradicts the classical east-towest headward erosion model.Instead,geomorphic analysis of the gorges—showing diachronous valley development from east to west—supports a progressive,bottom-to-top integration,initiated in the Xiling Gorge and culminating in the incision of the Qutang Gorge.This sequence aligns with knickpoint migration driven by base-level fall and regional tectonic uplift.We conclude that the evolution of the Yangtze River through the Three Gorges is the result of a complex interplay between climate,tectonics,and base-level dynamics,with terraces serving as key archives of landscape response to these forces.展开更多
The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the ...The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the research area.The reefs have different thicknesses ranging from 0.5 m to 11.5 m and lengths varying from 1 m to 130 m.The reef-building organisms include Archaeoscyphia, Recepthaculitids,Batostoma,Cyanobacteria and Pulchrilamina.Through the research of characteristics of the reef-bearing strata of the Early Ordovician in the Yichang area,four sorts of biofacies are recognized,which are(1) shelly biofacies:containing Tritoechia-Pelmatozans community and Tritoechia-Pomatotrema community;(2) reef biofacies:including the Batostoma,Calathium-Archaeoscyphia, Pelmatozoa-Batostoma,Archeoscyphia and Calathium-Cyanobacteria communities; (3) standing-water biofacies:including the Acanthograptus-Dendrogptus and Yichangopora communities;and(4) allochthonous biofacies:containing Nanorthis-Psilocephlina taphocoense community.The analysis of sea-level changes indicates that there are four cycles of sea-level changes during the period when reef-bearing strata were formed in this area,and the development of reefs is obviously controlled by the velocity of sea-level changes and the growth of accommodation space.The authors hold that reefs were mostly formed in the high sea level periods.Because of the development of several subordinate cycles during the sea-level rising,the reefs are characterized by great quantity, wide distribution,thin thickness and small scale,which are similar to that of Juassic reefs in northern Tibet.The research on the evolution of communities shows that succession and replacement are the main forms.The former is favorable to the development of reefs and the latter indicates the disappearance of reefs.展开更多
Yanjiahella gen. nov., a distinctive fossil taxon from the Early Cambrian Yanjiahe Biota in Yichang, Hubei Province, is characterized by： 1） an overall body plan composed of a stalk and a calyx （also arms in some s...Yanjiahella gen. nov., a distinctive fossil taxon from the Early Cambrian Yanjiahe Biota in Yichang, Hubei Province, is characterized by： 1） an overall body plan composed of a stalk and a calyx （also arms in some species）; 2） a stalk with closely spaced, transverse wrinkles and a medial, longitudinal ridge; and 3） a calyx preserved with three-dimensional radiating striations, as well as a probable madreporite in some specimens. Three species that can be assigned to this genus, which are Y. ancarpa sp. nov., Y. monocarpa sp. nov., and Y. biscarpa sp. nov. Yanjiahella is comparable to certain echinoderm taxa in terms of morphology and some biological structures, which might indicate the early evolution and diversification of ancestral echinoderm lineages from the early Early Cambrian Yangtze Platform. The discovery of putative echinoderms in the Yanjiahe Biota provides significant clues about the origination and evolution of the deuterostome phylum Echinodermata.展开更多
Taking the shale of Shuijingtuo Formation of Lower Cambrian in Yichang area as the research object,the shale reservoir characteristics are comprehensively evaluated and classified by fitting regression and formula cal...Taking the shale of Shuijingtuo Formation of Lower Cambrian in Yichang area as the research object,the shale reservoir characteristics are comprehensively evaluated and classified by fitting regression and formula calculation method in this study,using laboratory testing and geophysical logging data.The results show that the interpretation data of ECS(elemental capture spectroscopy)logging has a high correlation with the measured minerals data,which can be a good method to evaluate the minerals component of the shale.The calculated content of brittle minerals at the lower part of Shuijingtuo Formation is the relatively highest,generally more than 40%,which is the most favorable segment for fracturing.The correlation coefficient between the interpretation data of CMR(combinable nuclear magnetic resonance)logging and the result of laboratory porosity test is 0.97,which can effectively and accurately evaluate the reservoir porosity.The evaluation results show that the porosity of the lower member of Shuijingtuo Formation is generally greater than 3%,while that of the upper member is generally less than 3%.The lower segment is with the relative optimal physical conditions.There is a good correlation between the acoustic logging data and the gas bearing content testing results.A gas bearing content evaluation model is established.The results show that the gas bearing content of the lower 20 m shale is generally more than 2%,indicating that the lower part is a shale gas enrichment segment.Mechanical parameters such as Young modulus,Poisson ratio and brittleness index of shale reservoir are evaluated by using the logging data of P-wave time difference and S-wave time difference.The continuous 15 m shale at the lower part is with the relatively optimal low Poisson ratio,high Young modulus and high brittleness index,developing the optimum brittle condition.Based on the evaluation and classification of above parameters,the shale is divided into three types.The TypeⅠis the optimal,mainly located at the bottom.Its thickness is 8.5 m in total.The TypeⅡmainly develops at the middle part.The TypeⅢis the worst,mainly at the upper part.展开更多
The Three Gorges are considered to be critical to understand the formation of Yangtze River. Recent research results suggest that the Yangtze Three Gorges was created during the Quaternary but the exact time is debata...The Three Gorges are considered to be critical to understand the formation of Yangtze River. Recent research results suggest that the Yangtze Three Gorges was created during the Quaternary but the exact time is debatable. Fe-Ti oxide minerals are seldom used to study sediment provenance, expecially using scanning electron microscopy （SEM）, and energy dispersive spectrometer （EDS）. In this study, the provenance of Quaternary sediments in Yichang area, which is located to the east of the Yangtze Three Gorges, was investigated by using SEM and EDS to research Fe-Ti oxides. The Panzhihua vanadium titanomagnetite and Emeishan basalt outcrop are located to the west of the Three Gorges. Further, the materials from them are observed in the Quaternary sediments of Yichang area. Fe-Ti oxide minerals from the Huangling granite are observed in the Yunchi and Shanxiyao Formations, which were formed before 0.75 Ma B.P., whereas Fe-Ti oxide minerals from the Huangling granite, Panzhihua vanadium titanomagnetite, and Emeishan basalt are observed in the riverbed and fifth-terrace sediments of the Yangtze River, which were formed after 0.73 Ma B.P.. Thus, we can infer that the Three Gorges formed after the deposition of the Shanxi Formation and before the fifth-terrace; i.e., 0.75-0.73 Ma B.P..展开更多
Sandbars are of vital ecological and environmental significance, which however, have been intensively influenced by human activities. Morphodynamic processes of sandbars along the Yichang-Chenglingji Reach of the Chan...Sandbars are of vital ecological and environmental significance, which however, have been intensively influenced by human activities. Morphodynamic processes of sandbars along the Yichang-Chenglingji Reach of the Changjiang River, the channel immediately downstream of the Three Gorges Dam(TGD), are assessed based on remote sensing images between 2000 and 2016. It can be found that the entire area of sandbars reduces drastically by 19.23% from 149.04 km~2 in 2003 to 120.38 km~2 in 2016, accompanied with an increase in water surface width. Owing to differences in sediment grain size and anti-erosion capacity, sandbar area in the upstream sandy gravel reach(Yichang-Dabujie) and downstream sandy reach(Dabujie-Chenglingji) respectively decreases by 45.94%(from 20.79 km~2 to 11.24 km~2) and 14.93%(from 128.30 km~2 to 109.14 km~2). Furtherly, morphological evolutions of sandbars are affected by channel type: in straight-microbend channel, mid-channel sandbars exhibit downstream moving while maintaining the basic profile; in meandering channel, point sandbars show erosion and deposition in convex and concave bank respectively, with mid-channel sandbars distributing sporadically; in bending-branching channel, point sandbars experience erosion and move downstream while mid-channel sandbars show erosion in the head part along with retreating outline. We document that the primary mechanism of sandbars shrinkages along the Yichang-Chenglingji Reach can be attributed to TGD induced suspended sediment concentration decreasing and increasing in unsaturation of sediment carrying capacity. Additionally, channel type can affect the morphological evolution of sandbars. Along the Yichang-Chenglingji Reach, sandbars in straight-microbend channel are more affected by water flow than that in bending-branching channel.展开更多
Objective In recent years, the birth time and evolution of the Three Gorges, Yangtze River has become a focused topic. Different from previous studies, this study used provenance analysis of Quaternary sediments to di...Objective In recent years, the birth time and evolution of the Three Gorges, Yangtze River has become a focused topic. Different from previous studies, this study used provenance analysis of Quaternary sediments to discuss this question. Among those minerals in Quaternary sediments, magnetite was rarely studied. This paper presents element geochemistry and backscatter images of detrital magnetites from the Quaternary sediments in the Yichang area of Hubei Province. By discussing the provenance changes of detratic magnetites, we suggested the birth time of the Three Gorges of the Yangtze River.展开更多
Dialect is threatened by the increasing language contact. In Yichang, seldom young students speak its dialect. In this preliminary research, the author tries to clarify the actual language use and language attitude in...Dialect is threatened by the increasing language contact. In Yichang, seldom young students speak its dialect. In this preliminary research, the author tries to clarify the actual language use and language attitude in the community of family by the means of interviewing the parents living in Xiling district, both of whom could speak the dialect. It is found that the profession,education background of parents would influence their language attitude and actual choice of language to their children. The result shows that there exists significant disparity between the parents' language attitudes and the actual communication with their children. Reasons of such disparity and the public prediction of the tendency of Yichang dialect and provided. In the end, suggestions towards language policy are presented.展开更多
In recent years,leisure tourism in Yichang City of Hubei Province has been developed rapidly and has made great contribution to the economic development of Yichang City.Leisure tourism in Yichang City has entered a go...In recent years,leisure tourism in Yichang City of Hubei Province has been developed rapidly and has made great contribution to the economic development of Yichang City.Leisure tourism in Yichang City has entered a golden period of great development,great transformation,great improvement and great leap forward.However,while pursuing the development of tourism industry,it is required to pay attention to the problem of improving its industrial development.This article mainly studied the current situation and existing problems of tourism in Yichang.Finally,it came up with some solutions and suggestions about how to promote the development of leisure tourism in Yichang City.展开更多
Objective:To evaluate the clinical efficacy and safety of Chinese patent medicine Bupi Yichang Pill in the treatment of ulcerative colitis.Method:Use a computer to retrieve English and Chinese database(PubMed,EMBASE,C...Objective:To evaluate the clinical efficacy and safety of Chinese patent medicine Bupi Yichang Pill in the treatment of ulcerative colitis.Method:Use a computer to retrieve English and Chinese database(PubMed,EMBASE,CNKI,VIP,and Wanfang)from the establishment of the database to May 2020.The literature of clinical randomized controlled trials of Chinese patent medicine Bupi Yichang Pill for the treatment of ulcerative colitis were collected.Two researchers independently extracted the data and evaluated the quality of the included studies and meta-analysis was conducted by Using Stata 16.0 software,and the results were graded and evaluated by GRADE.Result:Eight studies with 835 patients were included.The overall analysis showed that Bupi Yichang Pill was more effective than mesalazine sustained-release granules both in mucosal score under colonoscopy(SMD=-0.93,95%CI[-1.20,-0.67])and total efficiency(RR=1.26,95%CI[1.11,1.43]).Compared with sulfasalazine,Bupi Yichang Pill produced a more significant effect in terms of total efficiency(RR=1.13,95%CI[1.05,1.21]).In the comparison of total symptom score,Bupi Yichang Pill group was lower than mesalazine sustained-release granules group(SMD=-0.94,95%CI[-1.16,-0.72]).The more adverse effect occurred in the mesalazine group when comparing with the Bupi Yichang Pill group(RR=0.46,95%CI[0.16,1.28]).Conclusion:Bupi Yichang Pill with great safety can effectively improve the clinical effectiveness of ulcerative colitis but the conclusions above are still needed a further study through the higher quality of evidence.展开更多
Yichang is not only one of the major industrial and commodity agricultural bases in Hubei, but also one of the important goods transient hubs. Since the State Council approved Yichang City independently running export...Yichang is not only one of the major industrial and commodity agricultural bases in Hubei, but also one of the important goods transient hubs. Since the State Council approved Yichang City independently running exports in 1988, it has steadily developed foreign trade along with deepening reform. In 1993, it earned foreign exchange worth US$24 million from exports, up by more than 60 percent over 1992.展开更多
Yichang City is the place where both the Three Gorges and the Gezhouba Dam projects are being constructed. Practice shows that any large State planned project will bring prosperity to the local economy. The Gezhouba D...Yichang City is the place where both the Three Gorges and the Gezhouba Dam projects are being constructed. Practice shows that any large State planned project will bring prosperity to the local economy. The Gezhouba Dam Project in Yichang has provided the first opportunity for the city’s development During the first stage of the Gezhouba project from 1971 to 1980, the annual average progressive growth rate of fixed assets investment and展开更多
The two renowned water control projects on the Yangtze River—— the Gezhouba Water Control Project and the Three Gorges Water Control Project——are both in Yichang attracting world attention for the region. The Yich...The two renowned water control projects on the Yangtze River—— the Gezhouba Water Control Project and the Three Gorges Water Control Project——are both in Yichang attracting world attention for the region. The Yichang Sub-Council of the China Council for the Promotion of International Trade (CCPIT Yichang Sub-Council) and the Yichang Chamber展开更多
The Three Gorges International Tourism Festival was held in Yichang, Hubei Province, from 1st to 7th October. The festival is a key component of the Chinese Folk Arts Tour sponsored by the China Tourism Administration...The Three Gorges International Tourism Festival was held in Yichang, Hubei Province, from 1st to 7th October. The festival is a key component of the Chinese Folk Arts Tour sponsored by the China Tourism Administration. The program of 20 events included the opening ceremony, the Three Gorges carnival, the evening fireworks party, the China netizen tourism festival, the Zhaojun tourism festival,展开更多
The Yichang section of the Three Gorges of the Yangtze River boasts abundant cultural resources and historical heritage.Thorough exploration and development of these cultural tourism resources,combined with the creati...The Yichang section of the Three Gorges of the Yangtze River boasts abundant cultural resources and historical heritage.Thorough exploration and development of these cultural tourism resources,combined with the creation of a unique cultural tourism identity for this section,can not only invigorate the development of the region’s tourism industry but also contribute significantly to cultural preservation and transmission.This study examines the development and current state of cultural tourism in the Three Gorges of the Yangtze River,focusing specifically on the Yichang section.Using the SWOT analysis method,it offers an in-depth analysis and proposes suggestions for cultural tourism development in this area,aiming to provide a reference for future tourism development strategies in the region.展开更多
Stratigraphic hiatuses of variable time intervals within the Rhuddanian to early Aeronian （Llandovery, Silurian） are identified in the area bordering East Chongqing, West Hubei and Northwest Hunan in central China. ...Stratigraphic hiatuses of variable time intervals within the Rhuddanian to early Aeronian （Llandovery, Silurian） are identified in the area bordering East Chongqing, West Hubei and Northwest Hunan in central China. Their distribution suggested the existence of a local uplift, traditionally named the Yichang Uplift. The diachronous nature of the basal black shale of the Lungmachi Formation crossing different belts of this Uplift signifies the various developing stages during the uplifting process. The present paper defines the temporal and spatial distribution pattern of the Yichang Uplift, which might be one of the important controlling factors for the preservation and distribution of the shale gas in this region, as it has been demonstrated that the shale gas exploration is generally less promising in the areas where more of the basal part of the Lungmachi Formation is missing. Therefore, better understanding of the circumjacent distribution pattern developed throughout the uplifting process may provide the important guidance for the shale gas exploration. The present work is a sister study to the published paper, ＂Stage-progressive distribution pattern of the Lungrnachian black graplolitic shales from Guizhou to Chongqing, Central China＂. These two studies thus provide a complete Ordovician-Silurian black shale distribution pattern in the Middle and Upper Yangtze, a region with the major shale gas fields in China.展开更多
基金supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF2023S1A5A2A01077716)。
文摘The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present new cosmogenic nuclide isochron burial ages for the fifth(T5)and fourth(T4)terraces,yielding ages of 0.49±0.05 Ma and 0.35±0.04 Ma,respectively.By integrating our data with existing 14C and ESR ages for lower terraces,we reconstruct a detailed incision history,showing~85 m of river downcutting since the Middle Pleistocene.Incision rates varied over time,with a notable acceleration after 0.1 Ma coinciding with the Gonghe movement of the Tibetan Plateau,highlighting the role of tectonic uplift in driving fluvial incision.The formation of the fifth terrace is associated with the Kunlun–Huanghe uplift,while the development of the fourth terrace corresponds to the phase of regional uplift in the Qinling Mountains.Sedimentological evidence further indicates that terrace formation was influenced by both climatic and tectonic controls:while T4 aggraded during a glacial period,T5 formed during the interglacial MIS 13 under strong monsoonal conditions—demonstrating that major aggradation can occur during warm phases.However,sustained incision required tectonic forcing,as climatic transitions alone were insufficient to drive deep bedrock erosion.Our results also constrain the longdebated integration of the Three Gorges.The 0.49 Ma age for T5 provides a robust minimum age for the hydrological connection between the Sichuan and Jianghan Basins.This timing,combined with the earlier formation of the"First Bend of the Yangtze"(Eocene–Miocene),contradicts the classical east-towest headward erosion model.Instead,geomorphic analysis of the gorges—showing diachronous valley development from east to west—supports a progressive,bottom-to-top integration,initiated in the Xiling Gorge and culminating in the incision of the Qutang Gorge.This sequence aligns with knickpoint migration driven by base-level fall and regional tectonic uplift.We conclude that the evolution of the Yangtze River through the Three Gorges is the result of a complex interplay between climate,tectonics,and base-level dynamics,with terraces serving as key archives of landscape response to these forces.
基金supported by the National Natural Science Foundation of China(No.40972019)the S&T plan projects of Hubei Provincial Education Department(No. 03Z0105)+1 种基金the Project of Scientific and Technologic Development Planning of Jingzhou(No.20101P031-5)the Innovative Experimenting Plan of Undergraduate Students of China(No.091048934)
文摘The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the research area.The reefs have different thicknesses ranging from 0.5 m to 11.5 m and lengths varying from 1 m to 130 m.The reef-building organisms include Archaeoscyphia, Recepthaculitids,Batostoma,Cyanobacteria and Pulchrilamina.Through the research of characteristics of the reef-bearing strata of the Early Ordovician in the Yichang area,four sorts of biofacies are recognized,which are(1) shelly biofacies:containing Tritoechia-Pelmatozans community and Tritoechia-Pomatotrema community;(2) reef biofacies:including the Batostoma,Calathium-Archaeoscyphia, Pelmatozoa-Batostoma,Archeoscyphia and Calathium-Cyanobacteria communities; (3) standing-water biofacies:including the Acanthograptus-Dendrogptus and Yichangopora communities;and(4) allochthonous biofacies:containing Nanorthis-Psilocephlina taphocoense community.The analysis of sea-level changes indicates that there are four cycles of sea-level changes during the period when reef-bearing strata were formed in this area,and the development of reefs is obviously controlled by the velocity of sea-level changes and the growth of accommodation space.The authors hold that reefs were mostly formed in the high sea level periods.Because of the development of several subordinate cycles during the sea-level rising,the reefs are characterized by great quantity, wide distribution,thin thickness and small scale,which are similar to that of Juassic reefs in northern Tibet.The research on the evolution of communities shows that succession and replacement are the main forms.The former is favorable to the development of reefs and the latter indicates the disappearance of reefs.
基金funded by National Basic Research Program of China(Grant No.40902007)the Special Fund for Basic Scientific Research of Central Colleges, Chang'an University,China(Grant Nos CHD2011TD005, CHD2011TD020,CHD2010JC074,CHD2009JC0018)+1 种基金the China Postdoctoral Science Foundation(Grant No. 20100471020)the Doctoral Fund of Ministry of Education of China(Grant No.20100205110003)
文摘Yanjiahella gen. nov., a distinctive fossil taxon from the Early Cambrian Yanjiahe Biota in Yichang, Hubei Province, is characterized by： 1） an overall body plan composed of a stalk and a calyx （also arms in some species）; 2） a stalk with closely spaced, transverse wrinkles and a medial, longitudinal ridge; and 3） a calyx preserved with three-dimensional radiating striations, as well as a probable madreporite in some specimens. Three species that can be assigned to this genus, which are Y. ancarpa sp. nov., Y. monocarpa sp. nov., and Y. biscarpa sp. nov. Yanjiahella is comparable to certain echinoderm taxa in terms of morphology and some biological structures, which might indicate the early evolution and diversification of ancestral echinoderm lineages from the early Early Cambrian Yangtze Platform. The discovery of putative echinoderms in the Yanjiahe Biota provides significant clues about the origination and evolution of the deuterostome phylum Echinodermata.
基金supported by the Fundamental and Commonweal Geological Survey of Oil and Gas of China(Nos.DD20179615 and DD20160194)the National Science and Technology Major Project of China(No.2016ZX05034001‐002).
文摘Taking the shale of Shuijingtuo Formation of Lower Cambrian in Yichang area as the research object,the shale reservoir characteristics are comprehensively evaluated and classified by fitting regression and formula calculation method in this study,using laboratory testing and geophysical logging data.The results show that the interpretation data of ECS(elemental capture spectroscopy)logging has a high correlation with the measured minerals data,which can be a good method to evaluate the minerals component of the shale.The calculated content of brittle minerals at the lower part of Shuijingtuo Formation is the relatively highest,generally more than 40%,which is the most favorable segment for fracturing.The correlation coefficient between the interpretation data of CMR(combinable nuclear magnetic resonance)logging and the result of laboratory porosity test is 0.97,which can effectively and accurately evaluate the reservoir porosity.The evaluation results show that the porosity of the lower member of Shuijingtuo Formation is generally greater than 3%,while that of the upper member is generally less than 3%.The lower segment is with the relative optimal physical conditions.There is a good correlation between the acoustic logging data and the gas bearing content testing results.A gas bearing content evaluation model is established.The results show that the gas bearing content of the lower 20 m shale is generally more than 2%,indicating that the lower part is a shale gas enrichment segment.Mechanical parameters such as Young modulus,Poisson ratio and brittleness index of shale reservoir are evaluated by using the logging data of P-wave time difference and S-wave time difference.The continuous 15 m shale at the lower part is with the relatively optimal low Poisson ratio,high Young modulus and high brittleness index,developing the optimum brittle condition.Based on the evaluation and classification of above parameters,the shale is divided into three types.The TypeⅠis the optimal,mainly located at the bottom.Its thickness is 8.5 m in total.The TypeⅡmainly develops at the middle part.The TypeⅢis the worst,mainly at the upper part.
基金supported by the Project of the National Natural Science Foundation of China (Grant No. 41572093, 41072083, 40602011)the Open Foundation of Shangdong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Mineralthe Cultivating Program of Young and Middle-aged Backbone Teachers of Chengdu University of Technology
文摘The Three Gorges are considered to be critical to understand the formation of Yangtze River. Recent research results suggest that the Yangtze Three Gorges was created during the Quaternary but the exact time is debatable. Fe-Ti oxide minerals are seldom used to study sediment provenance, expecially using scanning electron microscopy （SEM）, and energy dispersive spectrometer （EDS）. In this study, the provenance of Quaternary sediments in Yichang area, which is located to the east of the Yangtze Three Gorges, was investigated by using SEM and EDS to research Fe-Ti oxides. The Panzhihua vanadium titanomagnetite and Emeishan basalt outcrop are located to the west of the Three Gorges. Further, the materials from them are observed in the Quaternary sediments of Yichang area. Fe-Ti oxide minerals from the Huangling granite are observed in the Yunchi and Shanxiyao Formations, which were formed before 0.75 Ma B.P., whereas Fe-Ti oxide minerals from the Huangling granite, Panzhihua vanadium titanomagnetite, and Emeishan basalt are observed in the riverbed and fifth-terrace sediments of the Yangtze River, which were formed after 0.73 Ma B.P.. Thus, we can infer that the Three Gorges formed after the deposition of the Shanxi Formation and before the fifth-terrace; i.e., 0.75-0.73 Ma B.P..
基金National Natural Science Foundation of China,No.41576087National Science Foundation for Young Scientists of China,No.41706093Fund of the Key Laboratory of Coastal Science and Engineering,Beibu Gulf,Guangxi,No.2016ZZD01
文摘Sandbars are of vital ecological and environmental significance, which however, have been intensively influenced by human activities. Morphodynamic processes of sandbars along the Yichang-Chenglingji Reach of the Changjiang River, the channel immediately downstream of the Three Gorges Dam(TGD), are assessed based on remote sensing images between 2000 and 2016. It can be found that the entire area of sandbars reduces drastically by 19.23% from 149.04 km~2 in 2003 to 120.38 km~2 in 2016, accompanied with an increase in water surface width. Owing to differences in sediment grain size and anti-erosion capacity, sandbar area in the upstream sandy gravel reach(Yichang-Dabujie) and downstream sandy reach(Dabujie-Chenglingji) respectively decreases by 45.94%(from 20.79 km~2 to 11.24 km~2) and 14.93%(from 128.30 km~2 to 109.14 km~2). Furtherly, morphological evolutions of sandbars are affected by channel type: in straight-microbend channel, mid-channel sandbars exhibit downstream moving while maintaining the basic profile; in meandering channel, point sandbars show erosion and deposition in convex and concave bank respectively, with mid-channel sandbars distributing sporadically; in bending-branching channel, point sandbars experience erosion and move downstream while mid-channel sandbars show erosion in the head part along with retreating outline. We document that the primary mechanism of sandbars shrinkages along the Yichang-Chenglingji Reach can be attributed to TGD induced suspended sediment concentration decreasing and increasing in unsaturation of sediment carrying capacity. Additionally, channel type can affect the morphological evolution of sandbars. Along the Yichang-Chenglingji Reach, sandbars in straight-microbend channel are more affected by water flow than that in bending-branching channel.
基金financially supported by the National Natural Science Foundation of China (grants No.41072083 and 4157209)
文摘Objective In recent years, the birth time and evolution of the Three Gorges, Yangtze River has become a focused topic. Different from previous studies, this study used provenance analysis of Quaternary sediments to discuss this question. Among those minerals in Quaternary sediments, magnetite was rarely studied. This paper presents element geochemistry and backscatter images of detrital magnetites from the Quaternary sediments in the Yichang area of Hubei Province. By discussing the provenance changes of detratic magnetites, we suggested the birth time of the Three Gorges of the Yangtze River.
文摘Dialect is threatened by the increasing language contact. In Yichang, seldom young students speak its dialect. In this preliminary research, the author tries to clarify the actual language use and language attitude in the community of family by the means of interviewing the parents living in Xiling district, both of whom could speak the dialect. It is found that the profession,education background of parents would influence their language attitude and actual choice of language to their children. The result shows that there exists significant disparity between the parents' language attitudes and the actual communication with their children. Reasons of such disparity and the public prediction of the tendency of Yichang dialect and provided. In the end, suggestions towards language policy are presented.
文摘In recent years,leisure tourism in Yichang City of Hubei Province has been developed rapidly and has made great contribution to the economic development of Yichang City.Leisure tourism in Yichang City has entered a golden period of great development,great transformation,great improvement and great leap forward.However,while pursuing the development of tourism industry,it is required to pay attention to the problem of improving its industrial development.This article mainly studied the current situation and existing problems of tourism in Yichang.Finally,it came up with some solutions and suggestions about how to promote the development of leisure tourism in Yichang City.
基金National Natural Science Foundation of China(No.81673988)。
文摘Objective:To evaluate the clinical efficacy and safety of Chinese patent medicine Bupi Yichang Pill in the treatment of ulcerative colitis.Method:Use a computer to retrieve English and Chinese database(PubMed,EMBASE,CNKI,VIP,and Wanfang)from the establishment of the database to May 2020.The literature of clinical randomized controlled trials of Chinese patent medicine Bupi Yichang Pill for the treatment of ulcerative colitis were collected.Two researchers independently extracted the data and evaluated the quality of the included studies and meta-analysis was conducted by Using Stata 16.0 software,and the results were graded and evaluated by GRADE.Result:Eight studies with 835 patients were included.The overall analysis showed that Bupi Yichang Pill was more effective than mesalazine sustained-release granules both in mucosal score under colonoscopy(SMD=-0.93,95%CI[-1.20,-0.67])and total efficiency(RR=1.26,95%CI[1.11,1.43]).Compared with sulfasalazine,Bupi Yichang Pill produced a more significant effect in terms of total efficiency(RR=1.13,95%CI[1.05,1.21]).In the comparison of total symptom score,Bupi Yichang Pill group was lower than mesalazine sustained-release granules group(SMD=-0.94,95%CI[-1.16,-0.72]).The more adverse effect occurred in the mesalazine group when comparing with the Bupi Yichang Pill group(RR=0.46,95%CI[0.16,1.28]).Conclusion:Bupi Yichang Pill with great safety can effectively improve the clinical effectiveness of ulcerative colitis but the conclusions above are still needed a further study through the higher quality of evidence.
文摘Yichang is not only one of the major industrial and commodity agricultural bases in Hubei, but also one of the important goods transient hubs. Since the State Council approved Yichang City independently running exports in 1988, it has steadily developed foreign trade along with deepening reform. In 1993, it earned foreign exchange worth US$24 million from exports, up by more than 60 percent over 1992.
文摘Yichang City is the place where both the Three Gorges and the Gezhouba Dam projects are being constructed. Practice shows that any large State planned project will bring prosperity to the local economy. The Gezhouba Dam Project in Yichang has provided the first opportunity for the city’s development During the first stage of the Gezhouba project from 1971 to 1980, the annual average progressive growth rate of fixed assets investment and
文摘The two renowned water control projects on the Yangtze River—— the Gezhouba Water Control Project and the Three Gorges Water Control Project——are both in Yichang attracting world attention for the region. The Yichang Sub-Council of the China Council for the Promotion of International Trade (CCPIT Yichang Sub-Council) and the Yichang Chamber
文摘The Three Gorges International Tourism Festival was held in Yichang, Hubei Province, from 1st to 7th October. The festival is a key component of the Chinese Folk Arts Tour sponsored by the China Tourism Administration. The program of 20 events included the opening ceremony, the Three Gorges carnival, the evening fireworks party, the China netizen tourism festival, the Zhaojun tourism festival,
文摘The Yichang section of the Three Gorges of the Yangtze River boasts abundant cultural resources and historical heritage.Thorough exploration and development of these cultural tourism resources,combined with the creation of a unique cultural tourism identity for this section,can not only invigorate the development of the region’s tourism industry but also contribute significantly to cultural preservation and transmission.This study examines the development and current state of cultural tourism in the Three Gorges of the Yangtze River,focusing specifically on the Yichang section.Using the SWOT analysis method,it offers an in-depth analysis and proposes suggestions for cultural tourism development in this area,aiming to provide a reference for future tourism development strategies in the region.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB26000000)the National Natural Science Foundation of China (Grant Nos. U1562213 and 41502025)the National Science and Technology Major Project of China (Grant No. 2017ZX05035002-001)
文摘Stratigraphic hiatuses of variable time intervals within the Rhuddanian to early Aeronian （Llandovery, Silurian） are identified in the area bordering East Chongqing, West Hubei and Northwest Hunan in central China. Their distribution suggested the existence of a local uplift, traditionally named the Yichang Uplift. The diachronous nature of the basal black shale of the Lungmachi Formation crossing different belts of this Uplift signifies the various developing stages during the uplifting process. The present paper defines the temporal and spatial distribution pattern of the Yichang Uplift, which might be one of the important controlling factors for the preservation and distribution of the shale gas in this region, as it has been demonstrated that the shale gas exploration is generally less promising in the areas where more of the basal part of the Lungmachi Formation is missing. Therefore, better understanding of the circumjacent distribution pattern developed throughout the uplifting process may provide the important guidance for the shale gas exploration. The present work is a sister study to the published paper, ＂Stage-progressive distribution pattern of the Lungrnachian black graplolitic shales from Guizhou to Chongqing, Central China＂. These two studies thus provide a complete Ordovician-Silurian black shale distribution pattern in the Middle and Upper Yangtze, a region with the major shale gas fields in China.
