This article presents a real engineering project showcasing the application of span-bridge construction technology for building a highway that goes over a solutional cave.An overview of the project and the details of ...This article presents a real engineering project showcasing the application of span-bridge construction technology for building a highway that goes over a solutional cave.An overview of the project and the details of applying this technology in highway construction are provided.Besides,strategies for enhancing its construction quality are also proposed.The objective of this analysis is to improve the safety and quality of similar projects.展开更多
Cave animals are an excellent model system for studying adaptive evolution.At present,however,little is known about the mechanisms that enable surface colonizers to survive in the challenging environment of caves.One ...Cave animals are an excellent model system for studying adaptive evolution.At present,however,little is known about the mechanisms that enable surface colonizers to survive in the challenging environment of caves.One possibility is that these species have the necessary genetic background to respond with plastic changes to the pressures of underground habitats.To gain insight into this process,we conducted a comparative study with the fish species Telestes karsticus,which occurs in a hydrological system consisting of an interconnected stream and a cave.Results showed that T.karsticus resided year-round and spawned in Sušik cave,making it the first known cavefish in the Dinaric Karst.Cave and surface populations differed in morphological and physiological characteristics,as well as in patterns of gene expression without any evidence of genetic divergence.To test whether observed trait differences were plastic or genetic,we placed adult fish from both populations under light/dark or constant dark conditions.Common laboratory conditions erased all morphometric differences between the two morphs,suggesting phenotypic plasticity is driving the divergence of shape and size in wild fish.Lighter pigmentation and increased fat deposition exhibited by cave individuals were also observed in surface fish kept in the dark in the laboratory.Our study also revealed that specialized cave traits were not solely attributed to developmental plasticity,but also arose from adult responses,including acclimatization.Thus,we conclude that T.karsticus can adapt to cave conditions,with phenotypic plasticity playing an important role in the process of cave colonization.展开更多
DEAR EDITOR,The characiform fish Astyanax is a well-studied model system for understanding evolutionary development and genomics in cave biology.Nonetheless,considerable gaps remain in our understanding of its field e...DEAR EDITOR,The characiform fish Astyanax is a well-studied model system for understanding evolutionary development and genomics in cave biology.Nonetheless,considerable gaps remain in our understanding of its field ecology.Here,we conducted a fouryear field study and found that while cavefish spawned yearround,reproductive peaks occurred in January to February.展开更多
A hill can be regarded as an environmental carrier of heat.Water,rocks and the internal moisture naturally pre-sent in such environment constitute a natural heat accumulator.In the present study,the heat and moisture ...A hill can be regarded as an environmental carrier of heat.Water,rocks and the internal moisture naturally pre-sent in such environment constitute a natural heat accumulator.In the present study,the heat and moisture trans-fer characteristics in a representative hill cave have been simulated via a method relying on the Darcy’s law.The simulations have been conducted for both steady and unsteady conditions to discern the influence of permeability and geometric parameters on the thermal and moisture transfer processes.The reliability of the simulation has been verified through comparison of the numerical results with the annual observation data.As revealed by the numericalfindings,the internal temperature of the hill accumulator is proportional to the permeability,outside surface temperature,overground height,underground constant temperature layer depth,and underground tem-perature of the hill,and it is inversely proportional to the horizontal size of the hill.Moreover,in the considered case,the order of magnitude of the permeability of the hill is contained in the range 10-15–10-13,and displays a certain sensitivity to the rainwater seepage.展开更多
This paper investigates a unique and interesting archaeological case,namely the newly found inscription copied from Qianzi Wen(The Thousand Character Essay)on the south wall in the main chamber of Mogao cave 9,and ana...This paper investigates a unique and interesting archaeological case,namely the newly found inscription copied from Qianzi Wen(The Thousand Character Essay)on the south wall in the main chamber of Mogao cave 9,and analyzes a series of research topics related to the inscription,hoping to thoroughly reveal the historical and cultural phenomenon of the high popularity and extensive spread of Qianzi Wen in the Tang dynasty,and attempt to restore some living scenes of ancient school students and cave-making artisans.To the best of our knowledge,this is the first time to find Qianzi Wen on the wall in Mogao caves.展开更多
The Baiyun cave is a 380 m long karst cave in the Naigu Shilin, situated 70 km southeast of Kunming,Yunnan Province, China. The prevailing orientations of the cave passages are N110°-120°E and N0°-10...The Baiyun cave is a 380 m long karst cave in the Naigu Shilin, situated 70 km southeast of Kunming,Yunnan Province, China. The prevailing orientations of the cave passages are N110°-120°E and N0°-10°W and those of the fissures in the cave are N30°-40°W and N20°-30°W. The cave is developed in the thick-bedded Lower Permian Qixia Formation. The cave has an active water flow and is currently at the near water-table stage. There are large amounts of different infills of cave sediments. The cave shows different stages of paragenesis. The palaeomagnetic analysis of cave sediments shows that their ages are younger than 780 ka B.P. (the Brunhes Chron). The upper part of the sampled profile belongs to the reverse Blake event (112.3-117.9 ka B.P.). The formation of the Baiyun cave is directly connected with the development of the Naigu Shilin. The formation of karst underground and surface features depends on the regional tectonic deformation and the Cenozoic extension of the study area.展开更多
The Ak?akale Cave is located in the vicinity of the Arsa neighborhood within the boundaries of the Ak?akale village, Gümü?hane, Turkey. The cave is rich in cave formations(stalactite, stalagmite, cave pearl,...The Ak?akale Cave is located in the vicinity of the Arsa neighborhood within the boundaries of the Ak?akale village, Gümü?hane, Turkey. The cave is rich in cave formations(stalactite, stalagmite, cave pearl, cave flower, wall travertines). Thus, the appropriateness of opening the cave to visitors to boost tourism is of importance for the local and national economy. This study analyzes the stability of the Ak?akale Cave using a numerical analysis method. According to the results of the total displacement analysis, there are displacements in the entrance, ceiling, and sidewalls of the cave ranging from 1 mm to 48 mm. It seems that the entrance, ceiling, and sidewalls of the cave face a high risk of local or sudden collapse. According to the deformation analysis of the length section of the cave examined, local collapses may occur especially in the first 75 m from the entrance of the cave. We believe that this situation would not carry a risk for the Arsa neighborhood for now. In conclusion, the results of the stability analysis and in-situ observations showed clear evidence of former and ongoing cave-ins(collapses) and the Ak?akale Cave faces a high risk of local or sudden collapse. Thus, although the Ak?akale Cave is one of the most prominent karst caves in Turkey, it seems to be not appropriate to open the cave to tourist visits.展开更多
文摘This article presents a real engineering project showcasing the application of span-bridge construction technology for building a highway that goes over a solutional cave.An overview of the project and the details of applying this technology in highway construction are provided.Besides,strategies for enhancing its construction quality are also proposed.The objective of this analysis is to improve the safety and quality of similar projects.
基金supported by the Tenure Track Pilot Programme of the Croatian Science FoundationEcole Polytechnique Fédérale de Lausanne and Project TTP-2018-07-9675 Evolution in the Dark,with funds from the Croatian-Swiss Research Programme
文摘Cave animals are an excellent model system for studying adaptive evolution.At present,however,little is known about the mechanisms that enable surface colonizers to survive in the challenging environment of caves.One possibility is that these species have the necessary genetic background to respond with plastic changes to the pressures of underground habitats.To gain insight into this process,we conducted a comparative study with the fish species Telestes karsticus,which occurs in a hydrological system consisting of an interconnected stream and a cave.Results showed that T.karsticus resided year-round and spawned in Sušik cave,making it the first known cavefish in the Dinaric Karst.Cave and surface populations differed in morphological and physiological characteristics,as well as in patterns of gene expression without any evidence of genetic divergence.To test whether observed trait differences were plastic or genetic,we placed adult fish from both populations under light/dark or constant dark conditions.Common laboratory conditions erased all morphometric differences between the two morphs,suggesting phenotypic plasticity is driving the divergence of shape and size in wild fish.Lighter pigmentation and increased fat deposition exhibited by cave individuals were also observed in surface fish kept in the dark in the laboratory.Our study also revealed that specialized cave traits were not solely attributed to developmental plasticity,but also arose from adult responses,including acclimatization.Thus,we conclude that T.karsticus can adapt to cave conditions,with phenotypic plasticity playing an important role in the process of cave colonization.
基金supported by Marist College and its School of Science(to L.E.),an ANR grant(BLINDTEST),an FRM grant(Equipe FRM)(to S.R.),and a collaborative exchange program(Ecos-Nord)to S.R.and Patricia Ornelas-Garcia。
文摘DEAR EDITOR,The characiform fish Astyanax is a well-studied model system for understanding evolutionary development and genomics in cave biology.Nonetheless,considerable gaps remain in our understanding of its field ecology.Here,we conducted a fouryear field study and found that while cavefish spawned yearround,reproductive peaks occurred in January to February.
文摘A hill can be regarded as an environmental carrier of heat.Water,rocks and the internal moisture naturally pre-sent in such environment constitute a natural heat accumulator.In the present study,the heat and moisture trans-fer characteristics in a representative hill cave have been simulated via a method relying on the Darcy’s law.The simulations have been conducted for both steady and unsteady conditions to discern the influence of permeability and geometric parameters on the thermal and moisture transfer processes.The reliability of the simulation has been verified through comparison of the numerical results with the annual observation data.As revealed by the numericalfindings,the internal temperature of the hill accumulator is proportional to the permeability,outside surface temperature,overground height,underground constant temperature layer depth,and underground tem-perature of the hill,and it is inversely proportional to the horizontal size of the hill.Moreover,in the considered case,the order of magnitude of the permeability of the hill is contained in the range 10-15–10-13,and displays a certain sensitivity to the rainwater seepage.
基金This study was part of“The Investigation and Research of the Inscriptions Left by Visitors in the Past dynasties in Dunhuang Caves”supported by the Western Program of National Social and Scientific Fund(18XKG008).
文摘This paper investigates a unique and interesting archaeological case,namely the newly found inscription copied from Qianzi Wen(The Thousand Character Essay)on the south wall in the main chamber of Mogao cave 9,and analyzes a series of research topics related to the inscription,hoping to thoroughly reveal the historical and cultural phenomenon of the high popularity and extensive spread of Qianzi Wen in the Tang dynasty,and attempt to restore some living scenes of ancient school students and cave-making artisans.To the best of our knowledge,this is the first time to find Qianzi Wen on the wall in Mogao caves.
文摘The Baiyun cave is a 380 m long karst cave in the Naigu Shilin, situated 70 km southeast of Kunming,Yunnan Province, China. The prevailing orientations of the cave passages are N110°-120°E and N0°-10°W and those of the fissures in the cave are N30°-40°W and N20°-30°W. The cave is developed in the thick-bedded Lower Permian Qixia Formation. The cave has an active water flow and is currently at the near water-table stage. There are large amounts of different infills of cave sediments. The cave shows different stages of paragenesis. The palaeomagnetic analysis of cave sediments shows that their ages are younger than 780 ka B.P. (the Brunhes Chron). The upper part of the sampled profile belongs to the reverse Blake event (112.3-117.9 ka B.P.). The formation of the Baiyun cave is directly connected with the development of the Naigu Shilin. The formation of karst underground and surface features depends on the regional tectonic deformation and the Cenozoic extension of the study area.
文摘The Ak?akale Cave is located in the vicinity of the Arsa neighborhood within the boundaries of the Ak?akale village, Gümü?hane, Turkey. The cave is rich in cave formations(stalactite, stalagmite, cave pearl, cave flower, wall travertines). Thus, the appropriateness of opening the cave to visitors to boost tourism is of importance for the local and national economy. This study analyzes the stability of the Ak?akale Cave using a numerical analysis method. According to the results of the total displacement analysis, there are displacements in the entrance, ceiling, and sidewalls of the cave ranging from 1 mm to 48 mm. It seems that the entrance, ceiling, and sidewalls of the cave face a high risk of local or sudden collapse. According to the deformation analysis of the length section of the cave examined, local collapses may occur especially in the first 75 m from the entrance of the cave. We believe that this situation would not carry a risk for the Arsa neighborhood for now. In conclusion, the results of the stability analysis and in-situ observations showed clear evidence of former and ongoing cave-ins(collapses) and the Ak?akale Cave faces a high risk of local or sudden collapse. Thus, although the Ak?akale Cave is one of the most prominent karst caves in Turkey, it seems to be not appropriate to open the cave to tourist visits.
