Based on 33 U/Th dates and 1020 oxygen isotopic data from stalagmite Y1 from Yamen Cave, Guizhou Province, China, a record of the Asian Summer Monsoon (ASM) was established. The record covers the last deglaciation and...Based on 33 U/Th dates and 1020 oxygen isotopic data from stalagmite Y1 from Yamen Cave, Guizhou Province, China, a record of the Asian Summer Monsoon (ASM) was established. The record covers the last deglaciation and the early Holocene (from 16.2 to 7.3 ka BP) with an average oxygen isotope resolution of 9 years. The main millennial-scale deglacial events first identified in Greenland (Greenland Interstadial Events: GIS 1e through GIS 1a) and later in China are clearly present in the Y1 record. By analogy to earlier work, we refer to these as Chinese Interstadials (CIS): CIS A.1e to CIS A.1a. The onset of these events in Y1 δ18O records are nominally dated at: 14750±50, 14100±60, 13870±80, 13370±80, and 12990±80 a BP. The end of CIS A.1a or the beginning of the Younger Dryas (YD) event is nominally at 12850±50 a BP and the end of the YD dates to 11500±40 a BP. The δ18O values shift by close to 3‰ during the transition into the Bφlling-Allerφd (BA, the onset of CIS A.1e) and at the end of the YD. Comparisons of Y1 to previously published early Holocene records show no significant phase differences. Thus, the East Asia Monsoon and the Indian Monsoon do not appear to have been out of phase during this interval. The Y1 record confirms earlier work that suggested that solar insolation and North Atlantic climate both affect the Asian Monsoon.展开更多
One of eight gates of the Pearl River Estuary,the Yamen Inlet is a bedrock channel mouth connecting the Huangmao Sea and Yamen Channel.The wider water surfaces of the upper and lower reaches of the entrance produce a ...One of eight gates of the Pearl River Estuary,the Yamen Inlet is a bedrock channel mouth connecting the Huangmao Sea and Yamen Channel.The wider water surfaces of the upper and lower reaches of the entrance produce a unique bidirectional asymmetrical jet system.Using observed hydrology and historical charts,the ECOMSED model was applied in morphodynamic analysis of the dynamic structures and dynamic equilibrium of the Yamen jet system and its effect on sedimentation.It was found that (1) the nonlinear interaction of Yamen dynamic structures could not be ignored,as while the Coriolis force and friction force were generally of the same order of magnitude,the effect of friction force was greater;(2) the bidirectional asymmetrical jet system was flood preferential flow to the north of the channel mouth and ebb preferential flow to the south;and (3) the bidirectional asymmetrical jet system was the dominant factor in the long term stability of the Yamen deep trough.展开更多
Objective: To compare the risk angle and safety angle of n eedli ng Ya me n (GV 15) betwee n the atla nto-axial dislocati on (AAD) patients and healthy subjects. Methods: A total of 177 AAD patients diagnosed and trea...Objective: To compare the risk angle and safety angle of n eedli ng Ya me n (GV 15) betwee n the atla nto-axial dislocati on (AAD) patients and healthy subjects. Methods: A total of 177 AAD patients diagnosed and treated at the Center of Upper Cervical Vertebra of Beijing Chin a-Japa n Frie ndship Hospital betwee n January 2010 and January 2018 were in eluded in the AAD group. Ano ther 207 healthy subjects were included in the normal group. There were totally 191 males and 193 females. The MRI sean was performed for the cervical vertebrae to measure the risk angle and safety angle of acup un cture at Ya me n (GV 15) on the sagittal image. Results: In the AAD group, the risk angle was (13.14±3.99)° and the relative safety angle was (10.31±3.23)° for the perpendicular needling, while the oblique needling risk angle was (9.09±3.09)° for the male;the risk angle was (12.12±2.74)° and the relative safety angle was (10.56±2.09)° for the perpendicular needling, while the oblique needling risk angle was (9.70±2.95)° for the female. In the normal group, the risk angle was (7.89±1.59)° and the relative safety angle was (10.21±3.55)° for the perpendicular needling, while the oblique needling risk angle was (16.07±1.77)° for the male;the risk angle was (6.93±1.45)° and the relative safety angle was (10.70±2.94)° for the perpendicular needling, while the oblique needling risk angle was (14.89±2.18)° for the female. The perpendicular needling risk angles for the males and females in the AAD group were larger than those in the normal group, and the differences were statistically significant (both P<0.01);for the inner-group comparison, there was no sigrHficant difference in the perpendicular needling risk angle between the male and the female in the AAD group (P>0.05);however, the perpendicular needling risk angle for the male was larger than the female, and the differenee was statistically significant in the normal group (P<0.01). There were no sign讦icant differences in the relative safety angle for both the male and the female between the AAD group and the normal group (both P>0.05). For the inner-group comparison, there was no sign讦icant differenee in the relative safety angle between the male and the female (P>0.05). The oblique needling risk angles for both the males and females were smaller in the AAD group than those in the normal group, and the differences were statistically sign讦icant (both P<0.01);the oblique needling risk angle for the male was not significantly different from that for the female in the AAD group (P>0.05);in the normal group, the oblique needling risk angle for the male was larger than that for the female, and the differenee was statistically significant (P<0.01). Conclusion: Un der the AAD condition, the risk angle and safety angle of acup un cture at Ya me n (GV 15) cha nge significantly, perpe ndicular n eedli ng should be better if performed slightly lower tha n the horiz on tai di recti on, and the oblique needling should be safer across the occipital foramen toward the occipital bone.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 40231008, 40902053, 90511004, 40672165, 40772216)US National Science Foundation (Grant No. 052535)+4 种基金Science Foundation of Southwest University (Grant No. SWUB-2008047)Foundation of Karst Dynamics Laboratory, MLR (Grant No. 2006-05)National Key Program of Science and Technology (Grant No. 2006BAC01A16)Natural Science Foundation Project of Chongqing (Grant No. CSTC, 2009BA0002)Geological Survey Project of MLR (Grant No. 1212010634805)
文摘Based on 33 U/Th dates and 1020 oxygen isotopic data from stalagmite Y1 from Yamen Cave, Guizhou Province, China, a record of the Asian Summer Monsoon (ASM) was established. The record covers the last deglaciation and the early Holocene (from 16.2 to 7.3 ka BP) with an average oxygen isotope resolution of 9 years. The main millennial-scale deglacial events first identified in Greenland (Greenland Interstadial Events: GIS 1e through GIS 1a) and later in China are clearly present in the Y1 record. By analogy to earlier work, we refer to these as Chinese Interstadials (CIS): CIS A.1e to CIS A.1a. The onset of these events in Y1 δ18O records are nominally dated at: 14750±50, 14100±60, 13870±80, 13370±80, and 12990±80 a BP. The end of CIS A.1a or the beginning of the Younger Dryas (YD) event is nominally at 12850±50 a BP and the end of the YD dates to 11500±40 a BP. The δ18O values shift by close to 3‰ during the transition into the Bφlling-Allerφd (BA, the onset of CIS A.1e) and at the end of the YD. Comparisons of Y1 to previously published early Holocene records show no significant phase differences. Thus, the East Asia Monsoon and the Indian Monsoon do not appear to have been out of phase during this interval. The Y1 record confirms earlier work that suggested that solar insolation and North Atlantic climate both affect the Asian Monsoon.
基金supported by Guangdong Natural Science Foundation (Grant No. 9151027501000111)‘908’ Marine Survey Project (Grant No. 908-02-01-04)National Natural Science Foundation of China (Grant No. 50839005)
文摘One of eight gates of the Pearl River Estuary,the Yamen Inlet is a bedrock channel mouth connecting the Huangmao Sea and Yamen Channel.The wider water surfaces of the upper and lower reaches of the entrance produce a unique bidirectional asymmetrical jet system.Using observed hydrology and historical charts,the ECOMSED model was applied in morphodynamic analysis of the dynamic structures and dynamic equilibrium of the Yamen jet system and its effect on sedimentation.It was found that (1) the nonlinear interaction of Yamen dynamic structures could not be ignored,as while the Coriolis force and friction force were generally of the same order of magnitude,the effect of friction force was greater;(2) the bidirectional asymmetrical jet system was flood preferential flow to the north of the channel mouth and ebb preferential flow to the south;and (3) the bidirectional asymmetrical jet system was the dominant factor in the long term stability of the Yamen deep trough.
文摘Objective: To compare the risk angle and safety angle of n eedli ng Ya me n (GV 15) betwee n the atla nto-axial dislocati on (AAD) patients and healthy subjects. Methods: A total of 177 AAD patients diagnosed and treated at the Center of Upper Cervical Vertebra of Beijing Chin a-Japa n Frie ndship Hospital betwee n January 2010 and January 2018 were in eluded in the AAD group. Ano ther 207 healthy subjects were included in the normal group. There were totally 191 males and 193 females. The MRI sean was performed for the cervical vertebrae to measure the risk angle and safety angle of acup un cture at Ya me n (GV 15) on the sagittal image. Results: In the AAD group, the risk angle was (13.14±3.99)° and the relative safety angle was (10.31±3.23)° for the perpendicular needling, while the oblique needling risk angle was (9.09±3.09)° for the male;the risk angle was (12.12±2.74)° and the relative safety angle was (10.56±2.09)° for the perpendicular needling, while the oblique needling risk angle was (9.70±2.95)° for the female. In the normal group, the risk angle was (7.89±1.59)° and the relative safety angle was (10.21±3.55)° for the perpendicular needling, while the oblique needling risk angle was (16.07±1.77)° for the male;the risk angle was (6.93±1.45)° and the relative safety angle was (10.70±2.94)° for the perpendicular needling, while the oblique needling risk angle was (14.89±2.18)° for the female. The perpendicular needling risk angles for the males and females in the AAD group were larger than those in the normal group, and the differences were statistically significant (both P<0.01);for the inner-group comparison, there was no sigrHficant difference in the perpendicular needling risk angle between the male and the female in the AAD group (P>0.05);however, the perpendicular needling risk angle for the male was larger than the female, and the differenee was statistically significant in the normal group (P<0.01). There were no sign讦icant differences in the relative safety angle for both the male and the female between the AAD group and the normal group (both P>0.05). For the inner-group comparison, there was no sign讦icant differenee in the relative safety angle between the male and the female (P>0.05). The oblique needling risk angles for both the males and females were smaller in the AAD group than those in the normal group, and the differences were statistically sign讦icant (both P<0.01);the oblique needling risk angle for the male was not significantly different from that for the female in the AAD group (P>0.05);in the normal group, the oblique needling risk angle for the male was larger than that for the female, and the differenee was statistically significant (P<0.01). Conclusion: Un der the AAD condition, the risk angle and safety angle of acup un cture at Ya me n (GV 15) cha nge significantly, perpe ndicular n eedli ng should be better if performed slightly lower tha n the horiz on tai di recti on, and the oblique needling should be safer across the occipital foramen toward the occipital bone.
