NCEP/NCAR daily reanalysis data and Chinese daily gridded precipitation data are used to study the relationship between an aprupt drought-flood transition over the mid-low reaches of the Yangtze River in 2011 and the ...NCEP/NCAR daily reanalysis data and Chinese daily gridded precipitation data are used to study the relationship between an aprupt drought-flood transition over the mid-low reaches of the Yangtze River in 2011 and the intraseasonal oscillation （ISO; 30-60 days） in the mid-high latitude meridional circulation of the upper troposphere over East Asia. The abrupt transition from drought to flood occurs in early June. The first two recovered fields of the complex empirical orthogonal function show that northward-propagating westerlies from low latitudes converge with southward-propagating westerlies from high latitudes over the mid-low reaches of the Yangtze River （MLRYR） in mid late May. The timing of this convergence corresponds to the flood period in early-mid June. The ISO index is significantly and positively correlated with rainfall over the MLRYR. During the dry phase （before the transition）, the upper troposphere over the MLRYR is characterized by cyclonic flow, easterly winds, and convergence. The regional circulation is dominated by a wave train with a cyclone over east of Lake Baikal, an anticyclone over northern China, and a cyclone over the MLRYR. During the wet phase, the situation is reversed. The configuration of the wave train during the dry phase favors the southward propagation of westerly wind disturbances, while the configuration of the wave train during the wet phase favors the development and maintenance of a pumping effect and sustained ascending motions over the MLRYR.展开更多
Disintegration of rock is one of the primary processes of soil formation and geomorphology and is affected considerably by water and heat.This study focused on the disintegration characteristics under laboratory condi...Disintegration of rock is one of the primary processes of soil formation and geomorphology and is affected considerably by water and heat.This study focused on the disintegration characteristics under laboratory conditions of typical purple mudstone from the Tuodian group of Jurassic red beds(J3t) in Tuodian Town,Shuangbai county,Yunnan Province of southern China.The fresh mudstone was subjected to alternating applications of water,heat and hydrothermal interaction during five treatments:wetting-drying(WD),saturation(ST),refrigeration-heating(RH),a combination of wetting-drying and refrigeration-heating(WDRH),and a combination of saturation and refrigeration-heating(STRH).Each treatment was run in twenty-four cycles.The results showed that there are three types of disintegration:collapsing disintegration,exfoliation disintegration and imperceptible disintegration.The cumulative disintegration rate(percentage of cumulative disintegrated mass to the initiative sample mass passed through a 2 mm sieve) produced a 'S'-shape function when related to treatment cycle time and closely fit a logistic model(R2 > 0.99).The rank order of the cumulative disintegration rate resulting from the five treatments was as the following:WDRH > STRH > ST > WD > RH.Because of alternating periods of moisture and dryness,WD caused the most disintegration,while RH alone resulted in imperceptible disintegration.Additionally,there was a negative correlation between the disintegration rate of each treatment cycle(percentage of disintegrated mass to the treated sample mass) and treatment cycle number.There was a positive correlation between this rate and temperature change under moist conditions,indicating that a change in temperature greatly accelerates the disintegration of parent rock when water was supplied.展开更多
Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, ...Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order： Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement.展开更多
The GPS data in and around the Ordos block area indicate that the left-lateral slip rate along the northern or southern margin of the Ordos block is about twice or three times as fast as the right-lateral slip rate al...The GPS data in and around the Ordos block area indicate that the left-lateral slip rate along the northern or southern margin of the Ordos block is about twice or three times as fast as the right-lateral slip rate along the eastern or western margin of the block. However, many researchers stressed the dextral-slip of the eastern or western boundaries of the Ordos block, and suggested that the block as a whole rotated counterclockwise based on the available geological data. Focusing on the inconsistency, we reexamine the late Cenozoic deformation pattern in the Ordos region based on seismicity data and geodesy data (GPS and leveling) around it. The results indicate that the rigid block-like motion appears to be the basic characteristic of the kinematics of the Ordos region, and this motion is absorbed by the displacement of the faults around the block. When the faults along the northern and southern boundaries of the Ordos block are active, its eastern boundary is inactive. However, if the faults along the eastern boundary are active, the northern and southern are inactive. In recent years, the northern and southern boundaries of the Ordos block are in active. But in the long term, the Ordos block is moving southeastward relative to the Alxa and Yinshan blocks because of the strong pushing of the Tibetan Plateau on its southwestern side, and this deformation is accommodated by the counterclockwise rotation of the block itself.展开更多
According to the actual conditions in Sanshandao Gold Mine, the cancelling ore pillars mining method was researched. Firstly, a series of tests for the physical and mechanical characteristics of rock mass were carried...According to the actual conditions in Sanshandao Gold Mine, the cancelling ore pillars mining method was researched. Firstly, a series of tests for the physical and mechanical characteristics of rock mass were carried out and a quality classification system of rock mass applied in coastal metal deposit was established. Secondly, the reasonable demarcation depth of cancelling ore pillars was simulated using the finite element method, and the simulation results show that the ore pillars can be cancelled below the level of-555 m. Thirdly, a novel layer-backfill mining method of room-pillar alternation was designed to reduce the disturbance and settlement of terrain in mining area. Engineering practice shows that the new mining method enhanced the mining output and relieved rock disturbance. Furthermore, the settlement of the roof strata was small and no disaster occurred. The new mining technology effectively controlled the deformation of the terrain, indicating that the mining of the large-scale gold coastal deposit in Sanshandao Gold Mine was achieved safely, efficiently, and with a low loss rate.展开更多
The Earliest Triassic Yinkeng Formation is exposed at the well-known Meishan Section, South China, which contains the Global Stratotype of Section and Point （GSSP） for the Permian- Triassic boundary （PTB）. It reco...The Earliest Triassic Yinkeng Formation is exposed at the well-known Meishan Section, South China, which contains the Global Stratotype of Section and Point （GSSP） for the Permian- Triassic boundary （PTB）. It records centimeter-scale rhythmic alternations comprised mainly by marl- stone and limestone. Seven types of couplet embedded in five types of bundles were recognized based on occurrence and thickness of the lithologic units, suggesting that their formation was controlled by cyclic processes. The various orders of cycles observed correlate well with other Early Triassic counterparts recorded in South China. Here, we present new cyclostratigraphic results based on lithologic thickness and relative carbonate content of the Yinkeng Formation. Power spectra of carbonate content show that the ratio of major wavelengths recognized throughout the formation is similar to that of the 100 kyr short eccentricity, 33 kyr obliquity, and 21 kyr precession cycles, indicating that astronomical sig- nals are recorded in the Earliest Triassic rhythmic succession. Consistence between pronounced lithologic rhythmicity and sea-level changes obtained from Fischer plots indicates that high-frequency climatic cycles may have driven sea-level changes immediately after the PTB mass extinction. Fur- thermore, the 4th-order sea-level changes interpreted from the sedimentary record match well with 100 kyr short eccentricity component of carbonate content, reflecting that the 100 kyr short eccentricity- induced climate changes may have likely controlled the deposition of 4th-order sequences recognized from rhythmic successions.展开更多
This paper gives a summary of the fossil data from the Sinian Doushantuo' an Lantian Formation in the Xiuning area, Anhui Province, China, and reports the genital butt structure comparable to that of some modern a...This paper gives a summary of the fossil data from the Sinian Doushantuo' an Lantian Formation in the Xiuning area, Anhui Province, China, and reports the genital butt structure comparable to that of some modern advanced algae and the fossil structure comparable to the dehiscence of sporangia as well as the ontogenetic phenomenon occurring possibly from the formation of embryos by zygote germination to the production of sessile benthonic algal adults. This phenomenon furnishes a useful clue to the further study of the life history of alternate generations in advanced algae and provides megafossil evidence for the sex differentiation of metaphytic algae.展开更多
基金Supported by the National Natural Science Foundation of China (41221064 and 40875052)China Meteorological Administration Special Public Welfare Research Fund (GYHY200906017 and GYHY201006020)Basic Research Fund of the Chinese Academy of Meteorological Sciences (2010Z003)
文摘NCEP/NCAR daily reanalysis data and Chinese daily gridded precipitation data are used to study the relationship between an aprupt drought-flood transition over the mid-low reaches of the Yangtze River in 2011 and the intraseasonal oscillation （ISO; 30-60 days） in the mid-high latitude meridional circulation of the upper troposphere over East Asia. The abrupt transition from drought to flood occurs in early June. The first two recovered fields of the complex empirical orthogonal function show that northward-propagating westerlies from low latitudes converge with southward-propagating westerlies from high latitudes over the mid-low reaches of the Yangtze River （MLRYR） in mid late May. The timing of this convergence corresponds to the flood period in early-mid June. The ISO index is significantly and positively correlated with rainfall over the MLRYR. During the dry phase （before the transition）, the upper troposphere over the MLRYR is characterized by cyclonic flow, easterly winds, and convergence. The regional circulation is dominated by a wave train with a cyclone over east of Lake Baikal, an anticyclone over northern China, and a cyclone over the MLRYR. During the wet phase, the situation is reversed. The configuration of the wave train during the dry phase favors the southward propagation of westerly wind disturbances, while the configuration of the wave train during the wet phase favors the development and maintenance of a pumping effect and sustained ascending motions over the MLRYR.
基金supported by National Natural Science Foundation of China (Grant No.40971168)National Basic Research Program of China (973 Program) (Grant No. 2007CB407206)
文摘Disintegration of rock is one of the primary processes of soil formation and geomorphology and is affected considerably by water and heat.This study focused on the disintegration characteristics under laboratory conditions of typical purple mudstone from the Tuodian group of Jurassic red beds(J3t) in Tuodian Town,Shuangbai county,Yunnan Province of southern China.The fresh mudstone was subjected to alternating applications of water,heat and hydrothermal interaction during five treatments:wetting-drying(WD),saturation(ST),refrigeration-heating(RH),a combination of wetting-drying and refrigeration-heating(WDRH),and a combination of saturation and refrigeration-heating(STRH).Each treatment was run in twenty-four cycles.The results showed that there are three types of disintegration:collapsing disintegration,exfoliation disintegration and imperceptible disintegration.The cumulative disintegration rate(percentage of cumulative disintegrated mass to the initiative sample mass passed through a 2 mm sieve) produced a 'S'-shape function when related to treatment cycle time and closely fit a logistic model(R2 > 0.99).The rank order of the cumulative disintegration rate resulting from the five treatments was as the following:WDRH > STRH > ST > WD > RH.Because of alternating periods of moisture and dryness,WD caused the most disintegration,while RH alone resulted in imperceptible disintegration.Additionally,there was a negative correlation between the disintegration rate of each treatment cycle(percentage of disintegrated mass to the treated sample mass) and treatment cycle number.There was a positive correlation between this rate and temperature change under moist conditions,indicating that a change in temperature greatly accelerates the disintegration of parent rock when water was supplied.
基金Project supported by the National Natural Science Foundation of China (20671067, 30470150)
文摘Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order： Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement.
文摘The GPS data in and around the Ordos block area indicate that the left-lateral slip rate along the northern or southern margin of the Ordos block is about twice or three times as fast as the right-lateral slip rate along the eastern or western margin of the block. However, many researchers stressed the dextral-slip of the eastern or western boundaries of the Ordos block, and suggested that the block as a whole rotated counterclockwise based on the available geological data. Focusing on the inconsistency, we reexamine the late Cenozoic deformation pattern in the Ordos region based on seismicity data and geodesy data (GPS and leveling) around it. The results indicate that the rigid block-like motion appears to be the basic characteristic of the kinematics of the Ordos region, and this motion is absorbed by the displacement of the faults around the block. When the faults along the northern and southern boundaries of the Ordos block are active, its eastern boundary is inactive. However, if the faults along the eastern boundary are active, the northern and southern are inactive. In recent years, the northern and southern boundaries of the Ordos block are in active. But in the long term, the Ordos block is moving southeastward relative to the Alxa and Yinshan blocks because of the strong pushing of the Tibetan Plateau on its southwestern side, and this deformation is accommodated by the counterclockwise rotation of the block itself.
基金Projects(2013BAB02B03,2012BAB08B00)supported by the National Science and Technology Support Program of ChinaProject(51074177)supported by the Joint Funding of National Natural Science Foundation and Shanghai Baosteel Group CorporationProjects(51274254,51322403)supported by the National Natural Science Foundation of China
文摘According to the actual conditions in Sanshandao Gold Mine, the cancelling ore pillars mining method was researched. Firstly, a series of tests for the physical and mechanical characteristics of rock mass were carried out and a quality classification system of rock mass applied in coastal metal deposit was established. Secondly, the reasonable demarcation depth of cancelling ore pillars was simulated using the finite element method, and the simulation results show that the ore pillars can be cancelled below the level of-555 m. Thirdly, a novel layer-backfill mining method of room-pillar alternation was designed to reduce the disturbance and settlement of terrain in mining area. Engineering practice shows that the new mining method enhanced the mining output and relieved rock disturbance. Furthermore, the settlement of the roof strata was small and no disaster occurred. The new mining technology effectively controlled the deformation of the terrain, indicating that the mining of the large-scale gold coastal deposit in Sanshandao Gold Mine was achieved safely, efficiently, and with a low loss rate.
基金supported by the National Program on Key Basic Research Project(No.2012CB822000)the Na-tional Natural Science Foundation of China(No.41302113)+3 种基金China Postdoctoral Science Foundation(No.2013M531765)the Foundation of State Key Laboratory of Petroleum Re-sources and Prospecting,China University of Petroleum,Bei-jing(No.PRP/open-1301)the Project of Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education,China University of Geosciences(No.TPR-2012-06)the Fundamental Research Funds for the Central Universities of China(No.14CX02034A)
文摘The Earliest Triassic Yinkeng Formation is exposed at the well-known Meishan Section, South China, which contains the Global Stratotype of Section and Point （GSSP） for the Permian- Triassic boundary （PTB）. It records centimeter-scale rhythmic alternations comprised mainly by marl- stone and limestone. Seven types of couplet embedded in five types of bundles were recognized based on occurrence and thickness of the lithologic units, suggesting that their formation was controlled by cyclic processes. The various orders of cycles observed correlate well with other Early Triassic counterparts recorded in South China. Here, we present new cyclostratigraphic results based on lithologic thickness and relative carbonate content of the Yinkeng Formation. Power spectra of carbonate content show that the ratio of major wavelengths recognized throughout the formation is similar to that of the 100 kyr short eccentricity, 33 kyr obliquity, and 21 kyr precession cycles, indicating that astronomical sig- nals are recorded in the Earliest Triassic rhythmic succession. Consistence between pronounced lithologic rhythmicity and sea-level changes obtained from Fischer plots indicates that high-frequency climatic cycles may have driven sea-level changes immediately after the PTB mass extinction. Fur- thermore, the 4th-order sea-level changes interpreted from the sedimentary record match well with 100 kyr short eccentricity component of carbonate content, reflecting that the 100 kyr short eccentricity- induced climate changes may have likely controlled the deposition of 4th-order sequences recognized from rhythmic successions.
基金This study was supported by the National Natural Science Foundation of China Grant No.49472084
文摘This paper gives a summary of the fossil data from the Sinian Doushantuo' an Lantian Formation in the Xiuning area, Anhui Province, China, and reports the genital butt structure comparable to that of some modern advanced algae and the fossil structure comparable to the dehiscence of sporangia as well as the ontogenetic phenomenon occurring possibly from the formation of embryos by zygote germination to the production of sessile benthonic algal adults. This phenomenon furnishes a useful clue to the further study of the life history of alternate generations in advanced algae and provides megafossil evidence for the sex differentiation of metaphytic algae.
