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
A multitude of climate-adaptive design approaches are embedded in regional architecture,which have a positive impact on addressing the deformed development of urban spatial patterns and the dual challenges of climate ...A multitude of climate-adaptive design approaches are embedded in regional architecture,which have a positive impact on addressing the deformed development of urban spatial patterns and the dual challenges of climate and resources.This paper examines the principles of climate adaptability embedded in the site layout and spatial organization characteristics of traditional cave dwelling villages in northern Shaanxi Province.The extracted climate adaptability principles are summarized,and the resulting design strategies that are well-suited to the contemporary urban space form are presented.Through analysis,it can be observed that traditional cave dwelling villages in northern Shaanxi are predominantly situated on south-facing slopes in proximity to water at low altitudes.These villages are characterized by compact building groups and east-west development,which is constrained by the elements of mountains and rivers.A two-level street system is generated,comprising streets parallel to the contour line and roadways perpendicular to the contour line.This results in the formation of a courtyard form enclosed by mountains.Such site layout and spatial organization exhibit excellent climate adaptability with regard to heat,ventilation,and wind storage.In light of the aforementioned considerations,the following urban spatial form design strategies are put forth:①the topographic height difference can be exploited to obtain sufficient sunshine;②the group shape can be optimized in order to reduce building energy consumption;③the best orientation of the building can be chosen to take account of both winter and summer conditions;④the height and length can be combined in order to form natural masking;⑤the D/H ratio of streets and roadways should be controlled to achieve a balance between heat gain and cooling of groups;⑥vents should be set appropriately to optimize group ventilation;⑦climate buffers should be established to increase the level of climate response.展开更多
The utilization of caves is a rather rare phenomenon in nonhuman primates, found almost exclusively in those members of the genus Trachypithecus that share a preference for forest on limestone （karst） hills in Vietn...The utilization of caves is a rather rare phenomenon in nonhuman primates, found almost exclusively in those members of the genus Trachypithecus that share a preference for forest on limestone （karst） hills in Vietnam and southern China. Here we report a new case of usage of caves as overnight sleeping shelters by Franqois＇ or black langurs （Trachypithecusfraru;oisi） at Mayanghe National Nature Reserve in Yanhe County, Guizhou Province, China. We tentatively address three possible hypotheses that may account for the use of caves in Francois＇ langurs at Mayanghe： shelter against climatic conditions, acquisition of minerals and protection from predators. utilization展开更多
The rarity of limestone cave species due to habitat degradation makes them of special interest in conservation biology.The wild Chinese Giant Salamander Andrias davidianus,an evolutionarily distinct and globally endan...The rarity of limestone cave species due to habitat degradation makes them of special interest in conservation biology.The wild Chinese Giant Salamander Andrias davidianus,an evolutionarily distinct and globally endangered species,are nearly all obligate into living in inaccessible mountain caves now.We detected that only 14-29 breeders,with the effective population size of 9-25（5-44 of 95% confidence interval）,were in each of three caves,through genotyping 20 microsatellite loci on larvae that were flushed out of caves.Both heterzygosity excess and M（ratios of allele number to allele size range） tests indicated severe genetic bottlenecks among populations.Both mitochondrial,with only one or two haplotypes of D-loop region（770-771bp） in each population,and nuclear genetic structure showed clear divergence between populations.Considering the long life history,small population size,and genetic differentiationof the Chinese Giant Salamander,putting an end to poaching and recovering the karst ecosystem instead of releasing may be the sole measures to save this severely threated species.展开更多
Monitoring and sampling of main plants, soil CO2, soil water, bedrock, spring water, drip water and its corresponding speleothem were performed at four cave systems of Guizhou, Southwest China, from April 2003 to May ...Monitoring and sampling of main plants, soil CO2, soil water, bedrock, spring water, drip water and its corresponding speleothem were performed at four cave systems of Guizhou, Southwest China, from April 2003 to May 2004, in order to understand stable carbon isotope ratios variations of dissolved inorganic Carbon （DIC） in cave percolation waters （δ13CDIC） and their implications for paleoclimate. Stable carbon isotopic compositions and ions （Ca, Mg, Sr, SO4, CI etc.） were measured for all samples. The results indicate that there are significant differences among the δ13CDIC values from inter-cave, even inter-drip of intra-cave in the four caves. The δ13CDIC values from the Liangfeng Cave （LFC） is lightest among the four caves, where vegetation type overlying the cave is primary forest dominated by tall trees with lighter average δ13C value （-29.9‰）. And there are remarkable differences in δ13CDIC values of different drip waters in the Qixing Cave （QXC） and Jiangjun Cave （JJC）, up to 6.9‰ and 7.8‰, respectively. Further analyses show that the δ13CDIC values in cave drip waters are not only controlled by vegetation biomass overlying the cave, but also hydro-geochemical processes. Therefore, accurate interpreting of δ13C recorded in speleothems cannot be guaranteed if these effects of the above mentioned factors are not taken into consideration.展开更多
Lithium–sulfur(Li–S)batteries have become one of the most promising candidates for next-generation batteries owing to their high specific capacity,low cost,and environment-friendliness.Many efforts have been made to...Lithium–sulfur(Li–S)batteries have become one of the most promising candidates for next-generation batteries owing to their high specific capacity,low cost,and environment-friendliness.Many efforts have been made to mitigate the"shuttle effect"through physical adsorption and chemical bonding.MoS2 has been proposed as a cathode material to provide effective anchoring sites for lithium polysulfides(Li PSs),but is still limited by its layer structure.Herein,we designed novel MoS2 nanorods with inner caves based on our previous work,and performed synchronous encapsulation of sulfur during the synthesis process.The outer MoS2 tubular shells physically inhibit the outward diffusion of polysulfide species while the inner particles chemically anchor the polysulfides to prevent shuttling.As the cathode matrix in Li–S batteries,the electrochemical results deliver a high initial discharge capacity of 1213 mAhg^-1 for sulfur at 0.1 C.After cycling at 1 C for 300 cycles,the cells exhibit a capacity decay of only 0.076%per cycle and high average coulombic efficiency over 95%.The tubular MoS2 structure is an innovative and appealing design,which could be regarded as a prospective substrate for the improved performance of Li–S batteries.展开更多
Yunnan is famous for its attractive karst landscapes especially shilins, fengcong and fenglin. The development of caves beneath the shilins in the vicinity of Lunan is closely connected with the formation of shilins. ...Yunnan is famous for its attractive karst landscapes especially shilins, fengcong and fenglin. The development of caves beneath the shilins in the vicinity of Lunan is closely connected with the formation of shilins. Most of the waters percolating through shilins run through the caves beneath them and are responsible for their formation. The study of cave speleogenesis deepens knowledge about both the development of shilins and karst structure. In the vicinity of the Lunan Shilin, speleological, morphological and structural geological studies of four karst caves have been accomplished. At Puzhehei, Qiubei, which is characterised by numerous fenglin, fengcong and caves, speleological and morphological studies have been performed. Cave sediments for paleomagnetic analyses have been taken from all studied areas (samples CH 1-9). Karst caves in SE Yunnan are probably much older than the age of the cave sediments (<780,000 years B.P.). The studied areas are located in the vicinity of the Xiaojiang fault (N-S direction I and the Red River fault (NW-SE direction). The general directions of both active faults are assumed to influence the direction of the most frequent fissures as well as the cave passages near the Lunan Shilin. The Xiaojiang fault more strongly influences cave passage orientation, while the more distant Red River fault most strongly influences fissure orientation.展开更多
A review of the pressure transient analysis of flow in reservoirs having natural fractures,vugs and/or caves is presented to provide an insight into how much knowledge has been acquired about this phenomenon and to hi...A review of the pressure transient analysis of flow in reservoirs having natural fractures,vugs and/or caves is presented to provide an insight into how much knowledge has been acquired about this phenomenon and to highlight the gaps still open for further research.A comparison-based approach is adopted which involved the review of works by several authors and identifying the limiting assumptions,model restrictions and applicability.Pressure transient analysis provides information to aid the identification of important features of reservoirs.It also provides an explanation to complex reservoir pressuredependent variations which have led to improved understanding and optimization of the reservoir dynamics.Pressure transient analysis techniques,however,have limitations as not all its models find application in naturally fractured and vuggy reservoirs as the flow dynamics differ considerably.Pollard’s model presented in 1953 provided the foundation for existing pressure transient analysis in these types of reservoirs,and since then,several authors have modified this basic model and come up with more accurate models to characterize the dynamic pressure behavior in reservoirs with natural fractures,vugs and/or caves,with most having inherent limitations.This paper summarizes what has been done,what knowledge is considered established and the gaps left to be researched on.展开更多
Soil water and cave drip water from four cave systems in Guizhou, Southwest China, were monitored and sampled monthly from April 2003 to May 2004 to understand spatio-temporal variations in hydro-geochemistry of cave ...Soil water and cave drip water from four cave systems in Guizhou, Southwest China, were monitored and sampled monthly from April 2003 to May 2004 to understand spatio-temporal variations in hydro-geochemistry of cave percolation water. The results indicated that among the 5 drip water sites from the Liangfeng Cave (LFC), there were no significant differences among the hydro-geochemical parameters. In the Xiniu Cave (XNC), the drip rates were variable and responded quickly to precipitation events in the 3# (No. 3) drip site with variable water head; both bulk and variation in drip rates were smaller in the 2# with constant water head. However, in the Qixing Cave (QXC) and Jiangjun Cave (JJC), drip rates, concentrations of major ions and saturation index for calcite (SI C ) were smaller, and Mg/Ca ratios in Group I (1#, 2#, 6#, 7# and 8# in the QXC; 2# and 3# in the JJC) were larger than those in Group II (3#, 4#, 5# and 9# in the QXC; 1# and 4# in the JJC). These differences might be the result of different hydrogeological processes above the caves, which are divided into five categories based on hydro-geochemistry data. The formation of some proxies in speleothem, such as Mg/Ca, is likely to be affected by those processes.展开更多
Here we report first ever study on acoustical evaluation of Kanheri Caves located in Sanjay Gandhi National Park,Mumbai(Maharashtra,India).These caves are dated to a period between 2nd century BCE to 7th century CE.In...Here we report first ever study on acoustical evaluation of Kanheri Caves located in Sanjay Gandhi National Park,Mumbai(Maharashtra,India).These caves are dated to a period between 2nd century BCE to 7th century CE.In this study we used an ambisonic recorder to capture Impulse Response,which carries acoustic signature of the place.Out of total 109 caves 41 were surveyed in available time.Out of those reverberant environment was noted in 12 caves.Measurements were made only in 3 caves(Cave Nos.1,3,11)which are important.In the beginning we carried out an FFT analysis.We then studied room acoustic parameters like Reverberation Time,Early Decay Time,Clarity,Definition,etc.,based on the measurement of Impulse response.Cave No.3 have high value of reverberation time,compared to other.Therefore it also have lower clarity compared to others.It is properties needs to be compared with similar structures(chaityas)in Maharashtra(at Ajanta,Ellora,Nashik,Junnar,etc.)and elsewhere in India.It is worthwhile to carry out further research in Cave No.3 with more sophisticated instruments as well as 3D modeling.Since the experiment was performed with receiver at only one position,we also suggest to carry out experiment with receiver at multiple positions and then comparing them.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
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
Objective In recent years, the dispute regarding the Quatemary glacier of eastem China has become a research focus again, and one of the important focuses is the ＂glacial pothole＂. In fact, the micro-topographic ge...Objective In recent years, the dispute regarding the Quatemary glacier of eastem China has become a research focus again, and one of the important focuses is the ＂glacial pothole＂. In fact, the micro-topographic genesis of the rocky surface mortar may be interpreted differently in different places, including pothole, weathering pit, sea cave and wind-eroding pot. It is very controversial to determine this ＂glacial pothole＂.展开更多
The acronym C6 means ＂Climatic Changes and Carbon Cycle in Canyons and Caves＂. It is a monitoring project, for the evaluation of climate change signals, based on measuring sites located inside canyons and caves; it ...The acronym C6 means ＂Climatic Changes and Carbon Cycle in Canyons and Caves＂. It is a monitoring project, for the evaluation of climate change signals, based on measuring sites located inside canyons and caves; it merged in the year 2005, under the scientific supervision of the Palermo Branch of the Italian National Institute for Geophysics and Volcanology （INGV）, two different monitoring programs active since 1999. The choice of these environments is based on their morphological structure： being them more or less segregated respect the outer atmosphere, they act as low-pass filters respect the variations of the monitored parameters, which are rainfall and dropping water amounts and rates, air temperatures and relative humidity and carbon dioxide concentrations in the atmosphere. On the basis of the preliminary data, reported and discussed in the paper, the C6 network seems to be capable to give useful information on the local effects of global changes, even if at the moment the monitored parameters concern only the abiotic components of the studied ecosystems.展开更多
During A.D. 776 to 848, Dunhuang was occupied and ruled by Tubo political power, a special painting style, spread via the Tibetan silk road, appeared at same time, and which is related to the art style of India and Ne...During A.D. 776 to 848, Dunhuang was occupied and ruled by Tubo political power, a special painting style, spread via the Tibetan silk road, appeared at same time, and which is related to the art style of India and Nepal; It is worth noting that the Tibetan painting style during this period have no relative unified model actually, especially the mural and the silk painting preserved in Library Cave, the painting style of which had obvious difference between each other, and the reason behind this is very hard to explain. Until the late Tang Dynasty （A.D. 848-907）, sheer Pala style of eastern India appeared in Dunhuang, however, whether those East India painting style still belong to Tubo remain for further discussion. The art style of East India appeared in Dunhuang during from the late Tang Dynasty to the early period of Northern Song Dynasty, probably propagated from the ways other than Tubo, and this art style was deemed as the one has nothing to do with Tibet＇s art in this study.展开更多
CAPTIVATING Kuqa in the heart of Chinese Turkestan has stolen my heart. Luck has found me twice heading for this small county located in Aksu Prefecture on the rail line that connects Urumqi to Kashgar. Halfway betwee...CAPTIVATING Kuqa in the heart of Chinese Turkestan has stolen my heart. Luck has found me twice heading for this small county located in Aksu Prefecture on the rail line that connects Urumqi to Kashgar. Halfway between the oases of Kashgar and Turpan, Kuqa county seat has been a considerable trading center since ancient times.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
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Sponsored by Beijing Urban Governance Research Base of North China University of Technology(2024CSZL07).
文摘A multitude of climate-adaptive design approaches are embedded in regional architecture,which have a positive impact on addressing the deformed development of urban spatial patterns and the dual challenges of climate and resources.This paper examines the principles of climate adaptability embedded in the site layout and spatial organization characteristics of traditional cave dwelling villages in northern Shaanxi Province.The extracted climate adaptability principles are summarized,and the resulting design strategies that are well-suited to the contemporary urban space form are presented.Through analysis,it can be observed that traditional cave dwelling villages in northern Shaanxi are predominantly situated on south-facing slopes in proximity to water at low altitudes.These villages are characterized by compact building groups and east-west development,which is constrained by the elements of mountains and rivers.A two-level street system is generated,comprising streets parallel to the contour line and roadways perpendicular to the contour line.This results in the formation of a courtyard form enclosed by mountains.Such site layout and spatial organization exhibit excellent climate adaptability with regard to heat,ventilation,and wind storage.In light of the aforementioned considerations,the following urban spatial form design strategies are put forth:①the topographic height difference can be exploited to obtain sufficient sunshine;②the group shape can be optimized in order to reduce building energy consumption;③the best orientation of the building can be chosen to take account of both winter and summer conditions;④the height and length can be combined in order to form natural masking;⑤the D/H ratio of streets and roadways should be controlled to achieve a balance between heat gain and cooling of groups;⑥vents should be set appropriately to optimize group ventilation;⑦climate buffers should be established to increase the level of climate response.
文摘The utilization of caves is a rather rare phenomenon in nonhuman primates, found almost exclusively in those members of the genus Trachypithecus that share a preference for forest on limestone （karst） hills in Vietnam and southern China. Here we report a new case of usage of caves as overnight sleeping shelters by Franqois＇ or black langurs （Trachypithecusfraru;oisi） at Mayanghe National Nature Reserve in Yanhe County, Guizhou Province, China. We tentatively address three possible hypotheses that may account for the use of caves in Francois＇ langurs at Mayanghe： shelter against climatic conditions, acquisition of minerals and protection from predators. utilization
基金supported by National Key Programme of Research and Development (Ministry of Science and Technology,2016YFC0503200)NSFC (31570391,31200411,31360144 )+1 种基金Science and Technology Department of Sichuan Province (2012JY0101)Chinese Academy of Sciences (Y3C3011100).
文摘The rarity of limestone cave species due to habitat degradation makes them of special interest in conservation biology.The wild Chinese Giant Salamander Andrias davidianus,an evolutionarily distinct and globally endangered species,are nearly all obligate into living in inaccessible mountain caves now.We detected that only 14-29 breeders,with the effective population size of 9-25（5-44 of 95% confidence interval）,were in each of three caves,through genotyping 20 microsatellite loci on larvae that were flushed out of caves.Both heterzygosity excess and M（ratios of allele number to allele size range） tests indicated severe genetic bottlenecks among populations.Both mitochondrial,with only one or two haplotypes of D-loop region（770-771bp） in each population,and nuclear genetic structure showed clear divergence between populations.Considering the long life history,small population size,and genetic differentiationof the Chinese Giant Salamander,putting an end to poaching and recovering the karst ecosystem instead of releasing may be the sole measures to save this severely threated species.
基金funded by National Key Basic Research Development Program (Grant No. 2013CB956700)Orientation Project of Knowledge Innovation Program of Chinese Academy of Sciences (Grant No. kzcx2-yw-306)National Natural Science Foundation of China (Grant Nos. 41003054 and 90202003)
文摘Monitoring and sampling of main plants, soil CO2, soil water, bedrock, spring water, drip water and its corresponding speleothem were performed at four cave systems of Guizhou, Southwest China, from April 2003 to May 2004, in order to understand stable carbon isotope ratios variations of dissolved inorganic Carbon （DIC） in cave percolation waters （δ13CDIC） and their implications for paleoclimate. Stable carbon isotopic compositions and ions （Ca, Mg, Sr, SO4, CI etc.） were measured for all samples. The results indicate that there are significant differences among the δ13CDIC values from inter-cave, even inter-drip of intra-cave in the four caves. The δ13CDIC values from the Liangfeng Cave （LFC） is lightest among the four caves, where vegetation type overlying the cave is primary forest dominated by tall trees with lighter average δ13C value （-29.9‰）. And there are remarkable differences in δ13CDIC values of different drip waters in the Qixing Cave （QXC） and Jiangjun Cave （JJC）, up to 6.9‰ and 7.8‰, respectively. Further analyses show that the δ13CDIC values in cave drip waters are not only controlled by vegetation biomass overlying the cave, but also hydro-geochemical processes. Therefore, accurate interpreting of δ13C recorded in speleothems cannot be guaranteed if these effects of the above mentioned factors are not taken into consideration.
基金supported by the National Natural Science Foundation of China(No.21771143)Natural Science Foundation of Shaanxi Province(grant no.2017ZDJC-30,2018JQ2027)+4 种基金Key Research Project of Shaanxi Province(2018ZDCXLGY-08-06)Natural Science Foundation of Jiangsu Province(grant no.BK20170413)Fundamental Research Funds for the Central Universities(grant no.xjj2017084)Foshan Science and Technology Bureau Project(No.2017AG100443)supported by the Cyrus Tang Foundation through the Tang Scholar Program。
文摘Lithium–sulfur(Li–S)batteries have become one of the most promising candidates for next-generation batteries owing to their high specific capacity,low cost,and environment-friendliness.Many efforts have been made to mitigate the"shuttle effect"through physical adsorption and chemical bonding.MoS2 has been proposed as a cathode material to provide effective anchoring sites for lithium polysulfides(Li PSs),but is still limited by its layer structure.Herein,we designed novel MoS2 nanorods with inner caves based on our previous work,and performed synchronous encapsulation of sulfur during the synthesis process.The outer MoS2 tubular shells physically inhibit the outward diffusion of polysulfide species while the inner particles chemically anchor the polysulfides to prevent shuttling.As the cathode matrix in Li–S batteries,the electrochemical results deliver a high initial discharge capacity of 1213 mAhg^-1 for sulfur at 0.1 C.After cycling at 1 C for 300 cycles,the cells exhibit a capacity decay of only 0.076%per cycle and high average coulombic efficiency over 95%.The tubular MoS2 structure is an innovative and appealing design,which could be regarded as a prospective substrate for the improved performance of Li–S batteries.
文摘Yunnan is famous for its attractive karst landscapes especially shilins, fengcong and fenglin. The development of caves beneath the shilins in the vicinity of Lunan is closely connected with the formation of shilins. Most of the waters percolating through shilins run through the caves beneath them and are responsible for their formation. The study of cave speleogenesis deepens knowledge about both the development of shilins and karst structure. In the vicinity of the Lunan Shilin, speleological, morphological and structural geological studies of four karst caves have been accomplished. At Puzhehei, Qiubei, which is characterised by numerous fenglin, fengcong and caves, speleological and morphological studies have been performed. Cave sediments for paleomagnetic analyses have been taken from all studied areas (samples CH 1-9). Karst caves in SE Yunnan are probably much older than the age of the cave sediments (<780,000 years B.P.). The studied areas are located in the vicinity of the Xiaojiang fault (N-S direction I and the Red River fault (NW-SE direction). The general directions of both active faults are assumed to influence the direction of the most frequent fissures as well as the cave passages near the Lunan Shilin. The Xiaojiang fault more strongly influences cave passage orientation, while the more distant Red River fault most strongly influences fissure orientation.
基金the financial support received from the College of Petroleum Engineering and Geosciences at KFUPM through the project SF20006 toward the completion of this work。
文摘A review of the pressure transient analysis of flow in reservoirs having natural fractures,vugs and/or caves is presented to provide an insight into how much knowledge has been acquired about this phenomenon and to highlight the gaps still open for further research.A comparison-based approach is adopted which involved the review of works by several authors and identifying the limiting assumptions,model restrictions and applicability.Pressure transient analysis provides information to aid the identification of important features of reservoirs.It also provides an explanation to complex reservoir pressuredependent variations which have led to improved understanding and optimization of the reservoir dynamics.Pressure transient analysis techniques,however,have limitations as not all its models find application in naturally fractured and vuggy reservoirs as the flow dynamics differ considerably.Pollard’s model presented in 1953 provided the foundation for existing pressure transient analysis in these types of reservoirs,and since then,several authors have modified this basic model and come up with more accurate models to characterize the dynamic pressure behavior in reservoirs with natural fractures,vugs and/or caves,with most having inherent limitations.This paper summarizes what has been done,what knowledge is considered established and the gaps left to be researched on.
基金project was funded jointly by the Orientation Project of Knowledge Innovation Program sponsored by the Chinese Academy of Sciences (No. kzcx2-yw-306)the National Natural Science Foundation of China (Nos.41003054 and 90202003)
文摘Soil water and cave drip water from four cave systems in Guizhou, Southwest China, were monitored and sampled monthly from April 2003 to May 2004 to understand spatio-temporal variations in hydro-geochemistry of cave percolation water. The results indicated that among the 5 drip water sites from the Liangfeng Cave (LFC), there were no significant differences among the hydro-geochemical parameters. In the Xiniu Cave (XNC), the drip rates were variable and responded quickly to precipitation events in the 3# (No. 3) drip site with variable water head; both bulk and variation in drip rates were smaller in the 2# with constant water head. However, in the Qixing Cave (QXC) and Jiangjun Cave (JJC), drip rates, concentrations of major ions and saturation index for calcite (SI C ) were smaller, and Mg/Ca ratios in Group I (1#, 2#, 6#, 7# and 8# in the QXC; 2# and 3# in the JJC) were larger than those in Group II (3#, 4#, 5# and 9# in the QXC; 1# and 4# in the JJC). These differences might be the result of different hydrogeological processes above the caves, which are divided into five categories based on hydro-geochemistry data. The formation of some proxies in speleothem, such as Mg/Ca, is likely to be affected by those processes.
文摘Here we report first ever study on acoustical evaluation of Kanheri Caves located in Sanjay Gandhi National Park,Mumbai(Maharashtra,India).These caves are dated to a period between 2nd century BCE to 7th century CE.In this study we used an ambisonic recorder to capture Impulse Response,which carries acoustic signature of the place.Out of total 109 caves 41 were surveyed in available time.Out of those reverberant environment was noted in 12 caves.Measurements were made only in 3 caves(Cave Nos.1,3,11)which are important.In the beginning we carried out an FFT analysis.We then studied room acoustic parameters like Reverberation Time,Early Decay Time,Clarity,Definition,etc.,based on the measurement of Impulse response.Cave No.3 have high value of reverberation time,compared to other.Therefore it also have lower clarity compared to others.It is properties needs to be compared with similar structures(chaityas)in Maharashtra(at Ajanta,Ellora,Nashik,Junnar,etc.)and elsewhere in India.It is worthwhile to carry out further research in Cave No.3 with more sophisticated instruments as well as 3D modeling.Since the experiment was performed with receiver at only one position,we also suggest to carry out experiment with receiver at multiple positions and then comparing them.
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financially supported by the National Natural Science Foundation of China(grant No. 41472155)
文摘Objective In recent years, the dispute regarding the Quatemary glacier of eastem China has become a research focus again, and one of the important focuses is the ＂glacial pothole＂. In fact, the micro-topographic genesis of the rocky surface mortar may be interpreted differently in different places, including pothole, weathering pit, sea cave and wind-eroding pot. It is very controversial to determine this ＂glacial pothole＂.
文摘The acronym C6 means ＂Climatic Changes and Carbon Cycle in Canyons and Caves＂. It is a monitoring project, for the evaluation of climate change signals, based on measuring sites located inside canyons and caves; it merged in the year 2005, under the scientific supervision of the Palermo Branch of the Italian National Institute for Geophysics and Volcanology （INGV）, two different monitoring programs active since 1999. The choice of these environments is based on their morphological structure： being them more or less segregated respect the outer atmosphere, they act as low-pass filters respect the variations of the monitored parameters, which are rainfall and dropping water amounts and rates, air temperatures and relative humidity and carbon dioxide concentrations in the atmosphere. On the basis of the preliminary data, reported and discussed in the paper, the C6 network seems to be capable to give useful information on the local effects of global changes, even if at the moment the monitored parameters concern only the abiotic components of the studied ecosystems.
文摘During A.D. 776 to 848, Dunhuang was occupied and ruled by Tubo political power, a special painting style, spread via the Tibetan silk road, appeared at same time, and which is related to the art style of India and Nepal; It is worth noting that the Tibetan painting style during this period have no relative unified model actually, especially the mural and the silk painting preserved in Library Cave, the painting style of which had obvious difference between each other, and the reason behind this is very hard to explain. Until the late Tang Dynasty （A.D. 848-907）, sheer Pala style of eastern India appeared in Dunhuang, however, whether those East India painting style still belong to Tubo remain for further discussion. The art style of East India appeared in Dunhuang during from the late Tang Dynasty to the early period of Northern Song Dynasty, probably propagated from the ways other than Tubo, and this art style was deemed as the one has nothing to do with Tibet＇s art in this study.
文摘CAPTIVATING Kuqa in the heart of Chinese Turkestan has stolen my heart. Luck has found me twice heading for this small county located in Aksu Prefecture on the rail line that connects Urumqi to Kashgar. Halfway between the oases of Kashgar and Turpan, Kuqa county seat has been a considerable trading center since ancient times.
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.
