Based on the particularities of gas outbursts,i.e.,low gas bearing capacity and low gas pressure in the "Three Soft" coal seam in western Henan,we applied the theories of plate tectonics and regional structu...Based on the particularities of gas outbursts,i.e.,low gas bearing capacity and low gas pressure in the "Three Soft" coal seam in western Henan,we applied the theories of plate tectonics and regional structural evolution to investigate the mechanism of this seam and its impact on the coal seam gas formation.Our investigation revealed that coal and gas outbursts are distributed in a strip in a NW direction,with a number of high-penetration mines scattered towards the south side and low-gas mines largely located on the north side.We analyzed the statistics of 38 gas explosions and the rock-coal sturdiness number coefficient f of 167 sampling sites in the region and found the gas outburst mechanism that features a "low indicator outburst phenomenon".The mechanism is characterized by structural coal as its core,a low gas bearing capacity,low gas pressure and sturdiness coefficient f mostly less than 0.3.Our research results provide a theoretical foundation for effective control of gas disasters.展开更多
The history of the formation and development of Chinese civilization is also a civilization history of water conservancy. Water not only gives birth to Chinese civilization but also gives birth to the unique regional ...The history of the formation and development of Chinese civilization is also a civilization history of water conservancy. Water not only gives birth to Chinese civilization but also gives birth to the unique regional culture in Lingnan. In the past thousands of year, from the ancient myths and legends of Lingnan water conservancy culture to the digging of efficacious Canal＇s integration of the nationalities in Lingnan, to the blending of water and culture of the Xijiang River and the North River of the Zhujiang water system and the formation of urban river culture, development of its generation, deduction and inheritance has the mutual penetration with the formation of water system and the variation of water conservancy which mutually influence the historical evolvement of Lingnan regional culture.展开更多
This study aims to understand the particle size distribution and depositional styles of glacierassociated deposits in the Moxi basin in southwest China. Based on field surveys, 28 samples from glacier-associated depos...This study aims to understand the particle size distribution and depositional styles of glacierassociated deposits in the Moxi basin in southwest China. Based on field surveys, 28 samples from glacier-associated deposits(including glacial till,fluvioglacial, debris flow, river and lake deposits)were collected and tested in the laboratory. The results showed that the glacier-associated deposits can be differentiated based on particle gradation,particle size distribution and accumulated percentages. We evaluated the evolution of a former dammed lake in the Moxi basin based on glacierassociated deposits. The results of this study also indicated that the Moxi Platform was not formed by a single depositional process but is composed of both fluvioglacial and debris flow deposits. This research shows that the depositional style analysis is useful in identifying different glacier-associated deposits in high mountain regions. Moreover, the evaluation of the differences in particle sizes of the glacierassociated deposits is useful in reconstructing geohazard events in periglacial regions, and this information can help in identifying and reducing the potential risks associated with geo-hazards.展开更多
The coal seams in the Permian Taiyuan Formation and the Carboniferous Shanxi Formation are the primary reservoirs for the coalbed methane （CBM） in the Hancheng region in the Ordos Basin. In this paper, the origin an...The coal seams in the Permian Taiyuan Formation and the Carboniferous Shanxi Formation are the primary reservoirs for the coalbed methane （CBM） in the Hancheng region in the Ordos Basin. In this paper, the origin and evolution of waters associated with CBM production were studied on the basis of water chemistry and isotopes including the chloride and iodine compositions, oxygen and hydrogen stable isotopes, and radioactive isotope ratio of ^129I/^127I. The ratio of ^129I/^127I of water was determined by accelerator mass spectrometry （AMS）. The result shows that the formation water is of NaHCO3 and NaCl types with the total dissolved solids （TDS） varying from 1532.29 mg/L to 7061.12 mg/L. The values of ^129I and I/CI ratio indicate that the formation waters were diluted by meteoric water. The ^129I/^127I ratios range from 6.6×10^-13 to 1459.5~10-13. The ^129I/^127I ratios for most of the samples are between the ^129I/^127I initial value and that of recent anthropogenic water. This age of the formation water samples, obtained through the ^129I decay curve method, ranges from 0 Ma to 18.5 Ma, suggesting that the waters from the Taiyuan Formation and the Shanxi Formation are very young. Two different origins of water are identified in the Hancheng region. One group is dominated by pre-anthropogenic meteoric water, and is characterized by ^129I/^127I ratios lower than the initial value of 15×10^-13 and δD, δ^18O values of waters below the Global Meteoric Water Line. The other group is characterized by ^129I/^127I ratios in excess of 15×10^-13, which has undergone variable degrees of dilution by recent anthropogenic water.展开更多
Polo-like kinase 1 （Plkl）, a member of a family of serine/threonine kinases, is an attractive target for the development of anti- cancer drugs because it is involved in the regulation of cell-cycle progression and c...Polo-like kinase 1 （Plkl）, a member of a family of serine/threonine kinases, is an attractive target for the development of anti- cancer drugs because it is involved in the regulation of cell-cycle progression and cytokinesis. This kinase provides two pock- ets for developing Plkl inhibitors： the N-terminal catalytic domain （NCD） and the polo-box domain （PBD）. For both of the two pockets, some natural products were identified as Plkl inhibitors and some synthetic Plkl inhibitors were developed by mimicking ATP and phosphopeptides, natural products binding to NCD and PBD respectively. This article not only reviews the progression of Plkl inhibitors binding to these two pockets, but also discusses diversity evolution and jump in the process of drug development using Plkl inhibitors as examples and how they impact on drug design and pharmacopbore modeling.展开更多
Higher-order topological phases(HOTPs) are systems with topologically protected in-gap boundary states localized at their ed à nT-dimensional boundaries, with d the system dimension and n the order of the topolog...Higher-order topological phases(HOTPs) are systems with topologically protected in-gap boundary states localized at their ed à nT-dimensional boundaries, with d the system dimension and n the order of the topology. This work proposes a dynamics-based characterization of one large class of Z-type HOTPs without specifically relying on any crystalline symmetry considerations. The key element of our innovative approach is to connect quantum quench dynamics with nested configurations of the socalled band inversion surfaces(BISs) of momentum-space Hamiltonians as a sum of operators from the Clifford algebra(a condition that can be partially relaxed), thereby making it possible to dynamically detect each and every order of topology on an equal footing. Given that experiments on synthetic topological matter can directly measure the winding of certain pseudospin texture to determine topological features of BISs, the topological invariants defined through nested BISs are all within reach of ongoing experiments. Further, the necessity of having nested BISs in defining higher-order topology offers a unique perspective to investigate and engineer higher-order topological phase transitions.展开更多
基金support for this work,provided by the National Natural Science Foundation of China (No.50834005)
文摘Based on the particularities of gas outbursts,i.e.,low gas bearing capacity and low gas pressure in the "Three Soft" coal seam in western Henan,we applied the theories of plate tectonics and regional structural evolution to investigate the mechanism of this seam and its impact on the coal seam gas formation.Our investigation revealed that coal and gas outbursts are distributed in a strip in a NW direction,with a number of high-penetration mines scattered towards the south side and low-gas mines largely located on the north side.We analyzed the statistics of 38 gas explosions and the rock-coal sturdiness number coefficient f of 167 sampling sites in the region and found the gas outburst mechanism that features a "low indicator outburst phenomenon".The mechanism is characterized by structural coal as its core,a low gas bearing capacity,low gas pressure and sturdiness coefficient f mostly less than 0.3.Our research results provide a theoretical foundation for effective control of gas disasters.
文摘The history of the formation and development of Chinese civilization is also a civilization history of water conservancy. Water not only gives birth to Chinese civilization but also gives birth to the unique regional culture in Lingnan. In the past thousands of year, from the ancient myths and legends of Lingnan water conservancy culture to the digging of efficacious Canal＇s integration of the nationalities in Lingnan, to the blending of water and culture of the Xijiang River and the North River of the Zhujiang water system and the formation of urban river culture, development of its generation, deduction and inheritance has the mutual penetration with the formation of water system and the variation of water conservancy which mutually influence the historical evolvement of Lingnan regional culture.
基金funded by The China Geological Survey (Grant No. 12120113010200)Ministry of Science and Technology of the People’s Republic of China (Grant No. 2011FY110100-5)The National Natural Science Foundation of China (Grant No. 41101086)
文摘This study aims to understand the particle size distribution and depositional styles of glacierassociated deposits in the Moxi basin in southwest China. Based on field surveys, 28 samples from glacier-associated deposits(including glacial till,fluvioglacial, debris flow, river and lake deposits)were collected and tested in the laboratory. The results showed that the glacier-associated deposits can be differentiated based on particle gradation,particle size distribution and accumulated percentages. We evaluated the evolution of a former dammed lake in the Moxi basin based on glacierassociated deposits. The results of this study also indicated that the Moxi Platform was not formed by a single depositional process but is composed of both fluvioglacial and debris flow deposits. This research shows that the depositional style analysis is useful in identifying different glacier-associated deposits in high mountain regions. Moreover, the evaluation of the differences in particle sizes of the glacierassociated deposits is useful in reconstructing geohazard events in periglacial regions, and this information can help in identifying and reducing the potential risks associated with geo-hazards.
基金supported by National Basic Research Program of China(Grant No.2009CB219601)
文摘The coal seams in the Permian Taiyuan Formation and the Carboniferous Shanxi Formation are the primary reservoirs for the coalbed methane （CBM） in the Hancheng region in the Ordos Basin. In this paper, the origin and evolution of waters associated with CBM production were studied on the basis of water chemistry and isotopes including the chloride and iodine compositions, oxygen and hydrogen stable isotopes, and radioactive isotope ratio of ^129I/^127I. The ratio of ^129I/^127I of water was determined by accelerator mass spectrometry （AMS）. The result shows that the formation water is of NaHCO3 and NaCl types with the total dissolved solids （TDS） varying from 1532.29 mg/L to 7061.12 mg/L. The values of ^129I and I/CI ratio indicate that the formation waters were diluted by meteoric water. The ^129I/^127I ratios range from 6.6×10^-13 to 1459.5~10-13. The ^129I/^127I ratios for most of the samples are between the ^129I/^127I initial value and that of recent anthropogenic water. This age of the formation water samples, obtained through the ^129I decay curve method, ranges from 0 Ma to 18.5 Ma, suggesting that the waters from the Taiyuan Formation and the Shanxi Formation are very young. Two different origins of water are identified in the Hancheng region. One group is dominated by pre-anthropogenic meteoric water, and is characterized by ^129I/^127I ratios lower than the initial value of 15×10^-13 and δD, δ^18O values of waters below the Global Meteoric Water Line. The other group is characterized by ^129I/^127I ratios in excess of 15×10^-13, which has undergone variable degrees of dilution by recent anthropogenic water.
基金supported by the Fundamental Research Funds for the Central Universities(2013HGCH0015)
文摘Polo-like kinase 1 （Plkl）, a member of a family of serine/threonine kinases, is an attractive target for the development of anti- cancer drugs because it is involved in the regulation of cell-cycle progression and cytokinesis. This kinase provides two pock- ets for developing Plkl inhibitors： the N-terminal catalytic domain （NCD） and the polo-box domain （PBD）. For both of the two pockets, some natural products were identified as Plkl inhibitors and some synthetic Plkl inhibitors were developed by mimicking ATP and phosphopeptides, natural products binding to NCD and PBD respectively. This article not only reviews the progression of Plkl inhibitors binding to these two pockets, but also discusses diversity evolution and jump in the process of drug development using Plkl inhibitors as examples and how they impact on drug design and pharmacopbore modeling.
基金the Singapore Ministry of Education Academic Research Fund Tier-3 Grant No.MOE2017T3-1-001(WBS.No.R-144-000-425-592)the Singapore National Research Foundation Grant No.NRF-NRFI2017-04(WBS No.R-144-000-378-281)。
文摘Higher-order topological phases(HOTPs) are systems with topologically protected in-gap boundary states localized at their ed à nT-dimensional boundaries, with d the system dimension and n the order of the topology. This work proposes a dynamics-based characterization of one large class of Z-type HOTPs without specifically relying on any crystalline symmetry considerations. The key element of our innovative approach is to connect quantum quench dynamics with nested configurations of the socalled band inversion surfaces(BISs) of momentum-space Hamiltonians as a sum of operators from the Clifford algebra(a condition that can be partially relaxed), thereby making it possible to dynamically detect each and every order of topology on an equal footing. Given that experiments on synthetic topological matter can directly measure the winding of certain pseudospin texture to determine topological features of BISs, the topological invariants defined through nested BISs are all within reach of ongoing experiments. Further, the necessity of having nested BISs in defining higher-order topology offers a unique perspective to investigate and engineer higher-order topological phase transitions.
