A new species of the genusOdorrana is described from a completely dark karst cave of northeastern Guangxi, southern China. The new species,Odorranalipuensissp. nov., can be distinguished from its congeners by a combin...A new species of the genusOdorrana is described from a completely dark karst cave of northeastern Guangxi, southern China. The new species,Odorranalipuensissp. nov., can be distinguished from its congeners by a combination of the following characters: medium size (SVL: 40.7–47.7 mm in males, 51.1–55.4 mm in females);tips of all but ifrst ifnger expanded with circummarginal grooves; smooth, grass-green dorsum with irregular brown mottling; pineal body invisible; throat to upper abdomen with gray mottling; dorsal surfaces of limbs with brown bands; dorsolateral fold absent; tiny spinules on lateral body, temporal region, and anterior and posterior edge of tympanum;white nuptial pad present on ifnger I; males lacking vocal sacs; females having creamy yellow eggs, without black poles. Uncorrected sequence divergences betweenO.lipuensissp. nov. and all homologous 16S rRNA sequences ofOdorrana available on GenBank is equal to or greater than 4.9%. Currently, the new species is only known from the type locality.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
Baiyun Karst Caverns in Lincheng County,Hebei Province,is a rare karst caverns in subhumid climate region of the north.It was developed in carbonatite strata,particularly in Zhangxia formation of the Middle Cambrain s...Baiyun Karst Caverns in Lincheng County,Hebei Province,is a rare karst caverns in subhumid climate region of the north.It was developed in carbonatite strata,particularly in Zhangxia formation of the Middle Cambrain series.Erosion-corrosion landscape and chemical deposition landscape are abundant,They are various shapes,curtain drapery,cave flag,cave shield,stalactite,stalagmite,cave flowers,botryoid,soda straw are developed,especially heligmite,soda straw,cave flowers are the most characteristic.展开更多
From Ganqian (Tubo) Cave a total of 17 hominid teeth attributed to late Homo sapiens has been collected along with an abundance of mammalian fossils. The fossiliferous deposits are bracketed by the capping and second ...From Ganqian (Tubo) Cave a total of 17 hominid teeth attributed to late Homo sapiens has been collected along with an abundance of mammalian fossils. The fossiliferous deposits are bracketed by the capping and second flowstone layers, which yielded 230 Th/ 234 U dates of ~93 and ~220 ka, marking the minimum and maximum age of the hominid teeth respectively. Two U series methods performed on two mammalian teeth gave dates in the range of 85 and 139 ka, lending support to the stratigraphic order of the depositional sequence. The results presented in this paper point to an occurrence of modern Homo sapiens in southern China much earlier than has been thought, which is supported by the dating of nearby Liujiang and Bailiandong hominid sites. Taken together, these data suggest that China should not be considered as a backwater in recent human evolution where all the previous populations were replaced.展开更多
The island of Vis in the Adriatic Sea(Croatia)is a central Adriatic island.This is a small island(89.72 km^(2))but it has a large maritime zone(6,601 km^(2))featuring geologically very attractive open-sea islets known...The island of Vis in the Adriatic Sea(Croatia)is a central Adriatic island.This is a small island(89.72 km^(2))but it has a large maritime zone(6,601 km^(2))featuring geologically very attractive open-sea islets known for having rich fishing grounds.The Vis Archipelago was officially declared a UNESCO Geopark on April 18th 2019.This was the first area of the Croatian Adriatic to be included in the Global UNESCO Geopark Network.This paper presents the world-known monument of nature in the Adriatic Sea-the Blue Cave,a sea grotto of exceptional beauty on a small islet of Biševo in the Vis Archipelago Geopark.The author links the Blue Cave’s discovery to the beginning of tourism in Dalmatia,and he presents a few interesting commentaries and impressions of the Blue Cave by various visitors,especially in comparison to the more widely known Grotta Azzurra on the island of Capri near Naples(Italy).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
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
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
The relationship between support and surrounding rock is of great significance to the control of surrounding rock in mining process.In view of the fact that most of the existing numerical simulation methods construct ...The relationship between support and surrounding rock is of great significance to the control of surrounding rock in mining process.In view of the fact that most of the existing numerical simulation methods construct virtual elements and stress servo control to approximately replace the hydraulic support problem,this paper establishes a new numerical model of hydraulic support with the same working characteristics as the actual hydraulic support by integrating numerical simulation software Rhino,Griddle and FLAC3D,which can realize the simulation of different working conditions.Based on this model,the influence mechanism of the supporting strength of hydraulic support on surrounding rock stress regulation and coal stability in front of the top coal caving face in extra thick coal seam were researched.Firstly,under different support intensity,the abutment pressure of the bearing coal and the coal in front of it presents the “three-stage”evolution characteristics.The influence range of support intensity is 15%–30%.Secondly,1.5 MPa is the upper limit of impact that the support strength can have on the front coal failure area.Thirdly,within a displacement range of 2.76 m from the coal wall,a support strength of1.5 MPa provides optimal control of the horizontal displacement of the coal.展开更多
Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift ...Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift normal fault through detailed seismic interpretation and fault modeling.A total of 289 post-rift normal faults were identified in the study area and can be classified into four types:(1)isolated normal faults above the carbonate platform;(2)isolated normal faults cutting through the carbonate platform;(3)conjugate normal faults,and(4)connecting normal faults.Throw distribution analysis on the fault planes show that the vertical throw profiles of most normal fault exhibit flat-topped profiles.Isolated normal faults above the carbonate platform exhibit roughly concentric ellipses with maximum throw zones in the central section whereas the normal faults cutting through the carbonate platform miss the lowermost section due to the chaotic seismic reflections in the interior of the carbonate platform.The vertical throws of conjugate normal faults anomalously decrease toward their intersection region on the fault plane whereas the connecting normal faults present two maximum throw zones in the central section of the fault plane.According to the symmetric elliptical distribution model of fault throw,an estimation was made indicating that normal faults cutting through the carbonate platform extended downward between-1308 s and-1780 s(two-way travel time)in depth and may not penetrate the entire Liuhua carbonate platform.Moreover,it is observed that the distribution of karst caves on the top of the carbonate platform disaccord with those of hydrocarbon reservoirs and the post-rift normal faults cutting through the carbonate platform in the study area.We propose that these karst caves formed most probably by corrosive fluids derived from magmatic activities during the Dongsha event,rather than pore waters or hydrocarbons.展开更多
The deformation and fracture evolution mechanisms of the strata overlying mines mined using sublevel caving were studied via numerical simulations.Moreover,an expression for the normal force acting on the side face of...The deformation and fracture evolution mechanisms of the strata overlying mines mined using sublevel caving were studied via numerical simulations.Moreover,an expression for the normal force acting on the side face of a steeply dipping superimposed cantilever beam in the surrounding rock was deduced based on limit equilibrium theory.The results show the following:(1)surface displacement above metal mines with steeply dipping discontinuities shows significant step characteristics,and(2)the behavior of the strata as they fail exhibits superimposition characteristics.Generally,failure first occurs in certain superimposed strata slightly far from the goaf.Subsequently,with the constant downward excavation of the orebody,the superimposed strata become damaged both upwards away from and downwards toward the goaf.This process continues until the deep part of the steeply dipping superimposed strata forms a large-scale deep fracture plane that connects with the goaf.The deep fracture plane generally makes an angle of 12°-20°with the normal to the steeply dipping discontinuities.The effect of the constant outward transfer of strata movement due to the constant outward failure of the superimposed strata in the metal mines with steeply dipping discontinuities causes the scope of the strata movement in these mines to be larger than expected.The strata in the metal mines with steeply dipping discontinuities mainly show flexural toppling failure.However,the steeply dipping structural strata near the goaf mainly exhibit shear slipping failure,in which case the mechanical model used to describe them can be simplified by treating them as steeply dipping superimposed cantilever beams.By taking the steeply dipping superimposed cantilever beam that first experiences failure as the key stratum,the failure scope of the strata(and criteria for the stability of metal mines with steeply dipping discontinuities mined using sublevel caving)can be obtained via iterative computations from the key stratum,moving downward toward and upwards away from the goaf.展开更多
Mollusks, arthropods and chordates which were visible to the naked eye were observed and collected in Dongbei and Shuijiang caves of Libo county five times between February and July from 2002 to 2005. Four hundred and...Mollusks, arthropods and chordates which were visible to the naked eye were observed and collected in Dongbei and Shuijiang caves of Libo county five times between February and July from 2002 to 2005. Four hundred and forty samples from Dongbei Cave were classified into three phyla, five classes, 10 orders, 20 families and 39 species or groups of species. Four hundred and ninety-eight samples from Shuijiang Cave were classified into three phyla, six classes, 11 orders, 20 families and 25 species or groups of species. Six animal communities were identified in the light belt of the two caves according to their species types and numbers of individuals in the light belt of two cave. The communities which have the highest values of species richness community diversity, maximum diversity, evenness, dominance and community similarity are respectively: B (4. 1059), H (2.4716), B (3.3322), E (0.9042), C (0.3442) and A - C (0. 5251). The community diversity and correlation of environmental factors were also studied. The temperature, humidity, content of CO2 and N2, content of organic matter and some inorganic salts in soil were analyzed by Pearson correlation. The results showed that the content of organic matter in soil is positively related to species number, species richness and maximum community diversity, with correlations of 0. 885, 0.909, 0. 868 respectively (two-tailed significance test, P ≤ 0. 05), and significantly positively related to diversity, with the coefficient of 0.611, (two-tailed significance test, P ≤ 0. 1). This suggests that the content of organic matter in soil is one of the important elements influencing the community variation of cave animals. Outside the cave, temperature and humidity are important factors impacting on community diver- sity. As the temperature in all seasons in the cave is stable and the humidity is always high (above 90% ), the temperature and humidity have weak correlation to community diversity in caves.展开更多
There are many karst caves in China and each karst cave is a special part of natural landscape resources.How to exploit karst cave resources to develop tourism relates to the the effective exploitation of karst caves ...There are many karst caves in China and each karst cave is a special part of natural landscape resources.How to exploit karst cave resources to develop tourism relates to the the effective exploitation of karst caves resources.The author comprehensively analyzed the main influential factors of karst cave tourism development and concluded that the influential factors were the feature of karst caves resources,transportation condition,construction condition,regional economic development level,source market,regional combination of scenic spots,spatial competition,investors' decision-making behavior,local residents' attitudes and so on.The integrated action of these factors codetermines whether karst cave tourism development successes or not.Only by thoroughly realizing the status and role of every influential factor karst cave tourism development could be reasonably conducted,exploiting strong points and avoiding shortcomings.展开更多
Relevant ecotourism theories were applied to further investigate the mushrooming cave dwelling resorts on the Loess Plateau.By introducing the present development of cave dwelling settlements in the study area,types o...Relevant ecotourism theories were applied to further investigate the mushrooming cave dwelling resorts on the Loess Plateau.By introducing the present development of cave dwelling settlements in the study area,types of cave dwelling resort was summarized:historic cave dwelling resort based on high cultural value,artistic value and aesthetic value;cave dwelling resort characterized by primitive folk customs;cave hotel showing folk house features of the Loess Plateau.Luochuan Resort of the Loess Folk Customs,Miaoshang Resort of Sanmenxia,Stone Cave Hotel of Yangjialing in Yan'an were respectively studied to analyze features and development conditions of cave dwelling resort,on the basis of which development principles and countermeasures were discussed.The orientation of cave dwelling resort on the Loess Plateau should be determined first,sustainability and accountability of ecotourism should be followed.Finally,the significance of cave dwelling resort for promoting local economic development,enhancing the rational utilization of natural resources,protecting and developing traditional settlements of cave dwellings was given.展开更多
In view of traditional house in northern area of Shaanxi Province which was cave dwelling,based on cave dwelling and its development environment,the paper had analyzed architectural characteristics and use value of ca...In view of traditional house in northern area of Shaanxi Province which was cave dwelling,based on cave dwelling and its development environment,the paper had analyzed architectural characteristics and use value of cave dwelling and its development in northern Shaanxi,and then pointed out that cave dwelling development had been reduced into an awkward situation.By using SWOT analysis method,the strengths,weaknesses,opportunities and threats of cave dwellings had been summarized.In terms of strengths,cave dwelling had ecological advantage as native architecture,was constructed based on local conditions,could solve land,energy and environment problems on Loess Plateau,and abounded in aesthetic value of native feature.In terms of weaknesses,village layout lacked of integrity,transportation was not convenient,indoor ventilation and lighting were insufficient,and pattern and space were simplified and stereotyped.In terms of opportunities,it stressed architectural ecology having received more and more attention in the world,and exploration and application of underground civil architecture.In terms of threats,it lied in construction technology of cave dwelling,contradiction between cave dwelling and urbanization and between cave dwelling and modern life,and management mode of restricted type.On this basis,it suggested that cave dwelling development in northern Shaanxi should transform people's traditio-nal concept through correct guidance of public voice;strive to eliminate weakness of cave dwelling;improve cave environment by enhancing infrastructure construction;develop characteristic cave dwelling cultural tourism in northern Shaanxi,and construct new socialist countryside of northern Shaanxi character.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 studies of the oxgen and carbon isotopes of the rainwater in Guilin area, the drip water and the present carbonate deposit in Panlong cave of Guilin show that: (i) as to the general characteristics of the oxygen i...The studies of the oxgen and carbon isotopes of the rainwater in Guilin area, the drip water and the present carbonate deposit in Panlong cave of Guilin show that: (i) as to the general characteristics of the oxygen isotopes of the rainwater within a year and between years, the δ18O values decrease with an increase of air temperature and the rainfall, and the correlation between δ18O values and the mean monthly air temperature is much better than that between δ18O values and the rainfall, and the δ18O values of the rainwater during the summer monsoon are much smaller than those during winter monsoon; (ii) δ18O values of the drip water have a quite good correlation with the δ18O values of the rainwater in the same period; (iii) when the conditions are appropriate, δ13C can be used as an environmental proxy, that is, the smaller δ13C of speleothems is, the larger the proportion of C3 plants is and the more plentiful the rainfall is. On the contrary, C4plants may be prevailing or the environment may be a stony desert caused by climate changes or human activity.展开更多
基金supported by the Natural Science Foundation of Guangxi Province, China (Grant Nos: 2012GXNSFAA053057, 0832238)the ‘Xibuzhiguang’ Project of Chinese Academy of Sciences
文摘A new species of the genusOdorrana is described from a completely dark karst cave of northeastern Guangxi, southern China. The new species,Odorranalipuensissp. nov., can be distinguished from its congeners by a combination of the following characters: medium size (SVL: 40.7–47.7 mm in males, 51.1–55.4 mm in females);tips of all but ifrst ifnger expanded with circummarginal grooves; smooth, grass-green dorsum with irregular brown mottling; pineal body invisible; throat to upper abdomen with gray mottling; dorsal surfaces of limbs with brown bands; dorsolateral fold absent; tiny spinules on lateral body, temporal region, and anterior and posterior edge of tympanum;white nuptial pad present on ifnger I; males lacking vocal sacs; females having creamy yellow eggs, without black poles. Uncorrected sequence divergences betweenO.lipuensissp. nov. and all homologous 16S rRNA sequences ofOdorrana available on GenBank is equal to or greater than 4.9%. Currently, the new species is only known from the type locality.
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.
基金Supported by Major Special Projects of National Science and Technology Foundation(2011ZX05043-005)
文摘Baiyun Karst Caverns in Lincheng County,Hebei Province,is a rare karst caverns in subhumid climate region of the north.It was developed in carbonatite strata,particularly in Zhangxia formation of the Middle Cambrain series.Erosion-corrosion landscape and chemical deposition landscape are abundant,They are various shapes,curtain drapery,cave flag,cave shield,stalactite,stalagmite,cave flowers,botryoid,soda straw are developed,especially heligmite,soda straw,cave flowers are the most characteristic.
文摘From Ganqian (Tubo) Cave a total of 17 hominid teeth attributed to late Homo sapiens has been collected along with an abundance of mammalian fossils. The fossiliferous deposits are bracketed by the capping and second flowstone layers, which yielded 230 Th/ 234 U dates of ~93 and ~220 ka, marking the minimum and maximum age of the hominid teeth respectively. Two U series methods performed on two mammalian teeth gave dates in the range of 85 and 139 ka, lending support to the stratigraphic order of the depositional sequence. The results presented in this paper point to an occurrence of modern Homo sapiens in southern China much earlier than has been thought, which is supported by the dating of nearby Liujiang and Bailiandong hominid sites. Taken together, these data suggest that China should not be considered as a backwater in recent human evolution where all the previous populations were replaced.
文摘The island of Vis in the Adriatic Sea(Croatia)is a central Adriatic island.This is a small island(89.72 km^(2))but it has a large maritime zone(6,601 km^(2))featuring geologically very attractive open-sea islets known for having rich fishing grounds.The Vis Archipelago was officially declared a UNESCO Geopark on April 18th 2019.This was the first area of the Croatian Adriatic to be included in the Global UNESCO Geopark Network.This paper presents the world-known monument of nature in the Adriatic Sea-the Blue Cave,a sea grotto of exceptional beauty on a small islet of Biševo in the Vis Archipelago Geopark.The author links the Blue Cave’s discovery to the beginning of tourism in Dalmatia,and he presents a few interesting commentaries and impressions of the Blue Cave by various visitors,especially in comparison to the more widely known Grotta Azzurra on the island of Capri near Naples(Italy).
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.
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 Distinguished Youth Funds of National Natural Science Foundation of China (No.51925402)National Natural Science Foundation of China (Nos.51904203 and 52174125)+4 种基金the China Postdoctoral Science Foundation (No.2021M702049)the Tencent Foundation or XPLORER PRIZEShanxi Science and Technology Major Project Funds (No.20201102004)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering (No.2021SX-TD001)Open Fund Research Project Supported by State Key Laboratory of Strata Intelligent Control and Green Mining Co-founded by Shandong Province and the Ministry of Science and Technology (No.SICGM202209)。
文摘The relationship between support and surrounding rock is of great significance to the control of surrounding rock in mining process.In view of the fact that most of the existing numerical simulation methods construct virtual elements and stress servo control to approximately replace the hydraulic support problem,this paper establishes a new numerical model of hydraulic support with the same working characteristics as the actual hydraulic support by integrating numerical simulation software Rhino,Griddle and FLAC3D,which can realize the simulation of different working conditions.Based on this model,the influence mechanism of the supporting strength of hydraulic support on surrounding rock stress regulation and coal stability in front of the top coal caving face in extra thick coal seam were researched.Firstly,under different support intensity,the abutment pressure of the bearing coal and the coal in front of it presents the “three-stage”evolution characteristics.The influence range of support intensity is 15%–30%.Secondly,1.5 MPa is the upper limit of impact that the support strength can have on the front coal failure area.Thirdly,within a displacement range of 2.76 m from the coal wall,a support strength of1.5 MPa provides optimal control of the horizontal displacement of the coal.
基金The National Natural Science Foundation of China under contract No.42276066the Key Research and Development Program(International Science and Technology Cooperation Development Program)of Hainan Province under contract No.GHYF2022009the Youth Innovation Promotion Association of CAS under contract No.2018401.
文摘Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift normal fault through detailed seismic interpretation and fault modeling.A total of 289 post-rift normal faults were identified in the study area and can be classified into four types:(1)isolated normal faults above the carbonate platform;(2)isolated normal faults cutting through the carbonate platform;(3)conjugate normal faults,and(4)connecting normal faults.Throw distribution analysis on the fault planes show that the vertical throw profiles of most normal fault exhibit flat-topped profiles.Isolated normal faults above the carbonate platform exhibit roughly concentric ellipses with maximum throw zones in the central section whereas the normal faults cutting through the carbonate platform miss the lowermost section due to the chaotic seismic reflections in the interior of the carbonate platform.The vertical throws of conjugate normal faults anomalously decrease toward their intersection region on the fault plane whereas the connecting normal faults present two maximum throw zones in the central section of the fault plane.According to the symmetric elliptical distribution model of fault throw,an estimation was made indicating that normal faults cutting through the carbonate platform extended downward between-1308 s and-1780 s(two-way travel time)in depth and may not penetrate the entire Liuhua carbonate platform.Moreover,it is observed that the distribution of karst caves on the top of the carbonate platform disaccord with those of hydrocarbon reservoirs and the post-rift normal faults cutting through the carbonate platform in the study area.We propose that these karst caves formed most probably by corrosive fluids derived from magmatic activities during the Dongsha event,rather than pore waters or hydrocarbons.
基金Financial support for this work was provided by the Youth Fund Program of the National Natural Science Foundation of China (No. 42002292)the General Program of the National Natural Science Foundation of China (No. 42377175)the General Program of the Hubei Provincial Natural Science Foundation, China (No. 2023AFB631)
文摘The deformation and fracture evolution mechanisms of the strata overlying mines mined using sublevel caving were studied via numerical simulations.Moreover,an expression for the normal force acting on the side face of a steeply dipping superimposed cantilever beam in the surrounding rock was deduced based on limit equilibrium theory.The results show the following:(1)surface displacement above metal mines with steeply dipping discontinuities shows significant step characteristics,and(2)the behavior of the strata as they fail exhibits superimposition characteristics.Generally,failure first occurs in certain superimposed strata slightly far from the goaf.Subsequently,with the constant downward excavation of the orebody,the superimposed strata become damaged both upwards away from and downwards toward the goaf.This process continues until the deep part of the steeply dipping superimposed strata forms a large-scale deep fracture plane that connects with the goaf.The deep fracture plane generally makes an angle of 12°-20°with the normal to the steeply dipping discontinuities.The effect of the constant outward transfer of strata movement due to the constant outward failure of the superimposed strata in the metal mines with steeply dipping discontinuities causes the scope of the strata movement in these mines to be larger than expected.The strata in the metal mines with steeply dipping discontinuities mainly show flexural toppling failure.However,the steeply dipping structural strata near the goaf mainly exhibit shear slipping failure,in which case the mechanical model used to describe them can be simplified by treating them as steeply dipping superimposed cantilever beams.By taking the steeply dipping superimposed cantilever beam that first experiences failure as the key stratum,the failure scope of the strata(and criteria for the stability of metal mines with steeply dipping discontinuities mined using sublevel caving)can be obtained via iterative computations from the key stratum,moving downward toward and upwards away from the goaf.
文摘Mollusks, arthropods and chordates which were visible to the naked eye were observed and collected in Dongbei and Shuijiang caves of Libo county five times between February and July from 2002 to 2005. Four hundred and forty samples from Dongbei Cave were classified into three phyla, five classes, 10 orders, 20 families and 39 species or groups of species. Four hundred and ninety-eight samples from Shuijiang Cave were classified into three phyla, six classes, 11 orders, 20 families and 25 species or groups of species. Six animal communities were identified in the light belt of the two caves according to their species types and numbers of individuals in the light belt of two cave. The communities which have the highest values of species richness community diversity, maximum diversity, evenness, dominance and community similarity are respectively: B (4. 1059), H (2.4716), B (3.3322), E (0.9042), C (0.3442) and A - C (0. 5251). The community diversity and correlation of environmental factors were also studied. The temperature, humidity, content of CO2 and N2, content of organic matter and some inorganic salts in soil were analyzed by Pearson correlation. The results showed that the content of organic matter in soil is positively related to species number, species richness and maximum community diversity, with correlations of 0. 885, 0.909, 0. 868 respectively (two-tailed significance test, P ≤ 0. 05), and significantly positively related to diversity, with the coefficient of 0.611, (two-tailed significance test, P ≤ 0. 1). This suggests that the content of organic matter in soil is one of the important elements influencing the community variation of cave animals. Outside the cave, temperature and humidity are important factors impacting on community diver- sity. As the temperature in all seasons in the cave is stable and the humidity is always high (above 90% ), the temperature and humidity have weak correlation to community diversity in caves.
基金Supported by Financing Project of Institute of Karst Geology,Chinese Academy of Geological Sciences (2009021)Financing Project of Guan-gxi Science and Technology Agency (Guangxi Scientific Research and Technological Development Planning Program 0719005-1-5) ~~
文摘There are many karst caves in China and each karst cave is a special part of natural landscape resources.How to exploit karst cave resources to develop tourism relates to the the effective exploitation of karst caves resources.The author comprehensively analyzed the main influential factors of karst cave tourism development and concluded that the influential factors were the feature of karst caves resources,transportation condition,construction condition,regional economic development level,source market,regional combination of scenic spots,spatial competition,investors' decision-making behavior,local residents' attitudes and so on.The integrated action of these factors codetermines whether karst cave tourism development successes or not.Only by thoroughly realizing the status and role of every influential factor karst cave tourism development could be reasonably conducted,exploiting strong points and avoiding shortcomings.
基金Supported by Program of Social Science Joint Association of Henan Province(SKL-2009-3256)~~
文摘Relevant ecotourism theories were applied to further investigate the mushrooming cave dwelling resorts on the Loess Plateau.By introducing the present development of cave dwelling settlements in the study area,types of cave dwelling resort was summarized:historic cave dwelling resort based on high cultural value,artistic value and aesthetic value;cave dwelling resort characterized by primitive folk customs;cave hotel showing folk house features of the Loess Plateau.Luochuan Resort of the Loess Folk Customs,Miaoshang Resort of Sanmenxia,Stone Cave Hotel of Yangjialing in Yan'an were respectively studied to analyze features and development conditions of cave dwelling resort,on the basis of which development principles and countermeasures were discussed.The orientation of cave dwelling resort on the Loess Plateau should be determined first,sustainability and accountability of ecotourism should be followed.Finally,the significance of cave dwelling resort for promoting local economic development,enhancing the rational utilization of natural resources,protecting and developing traditional settlements of cave dwellings was given.
基金Supported by Scientific Research Project of Weinan Teachers University(10YKS013)~~
文摘In view of traditional house in northern area of Shaanxi Province which was cave dwelling,based on cave dwelling and its development environment,the paper had analyzed architectural characteristics and use value of cave dwelling and its development in northern Shaanxi,and then pointed out that cave dwelling development had been reduced into an awkward situation.By using SWOT analysis method,the strengths,weaknesses,opportunities and threats of cave dwellings had been summarized.In terms of strengths,cave dwelling had ecological advantage as native architecture,was constructed based on local conditions,could solve land,energy and environment problems on Loess Plateau,and abounded in aesthetic value of native feature.In terms of weaknesses,village layout lacked of integrity,transportation was not convenient,indoor ventilation and lighting were insufficient,and pattern and space were simplified and stereotyped.In terms of opportunities,it stressed architectural ecology having received more and more attention in the world,and exploration and application of underground civil architecture.In terms of threats,it lied in construction technology of cave dwelling,contradiction between cave dwelling and urbanization and between cave dwelling and modern life,and management mode of restricted type.On this basis,it suggested that cave dwelling development in northern Shaanxi should transform people's traditio-nal concept through correct guidance of public voice;strive to eliminate weakness of cave dwelling;improve cave environment by enhancing infrastructure construction;develop characteristic cave dwelling cultural tourism in northern Shaanxi,and construct new socialist countryside of northern Shaanxi character.
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
文摘The studies of the oxgen and carbon isotopes of the rainwater in Guilin area, the drip water and the present carbonate deposit in Panlong cave of Guilin show that: (i) as to the general characteristics of the oxygen isotopes of the rainwater within a year and between years, the δ18O values decrease with an increase of air temperature and the rainfall, and the correlation between δ18O values and the mean monthly air temperature is much better than that between δ18O values and the rainfall, and the δ18O values of the rainwater during the summer monsoon are much smaller than those during winter monsoon; (ii) δ18O values of the drip water have a quite good correlation with the δ18O values of the rainwater in the same period; (iii) when the conditions are appropriate, δ13C can be used as an environmental proxy, that is, the smaller δ13C of speleothems is, the larger the proportion of C3 plants is and the more plentiful the rainfall is. On the contrary, C4plants may be prevailing or the environment may be a stony desert caused by climate changes or human activity.