Objective In order to reduce the interfering noise from the earth surface, scientists have carried out multi-geophysical borehole observations and the related study. This study aims at improving signal-to-noise ratio ...Objective In order to reduce the interfering noise from the earth surface, scientists have carried out multi-geophysical borehole observations and the related study. This study aims at improving signal-to-noise ratio obtained from the observation data to obtain zero noise data, which will be of great help to improve geophysical studies. Insights from this study will be significant for the earthquake disaster reduction, resource exploration and environmental protection.展开更多
The Hongyancun subway station in Chongqing,China,is 116 meters deep and the difference in air pressure often leaves users with clogged(堵塞的)ears when accessed via its elevator.When the air pressure outside the eardr...The Hongyancun subway station in Chongqing,China,is 116 meters deep and the difference in air pressure often leaves users with clogged(堵塞的)ears when accessed via its elevator.When the air pressure outside the eardrum(耳膜)becomes different than the pressure inside,you experience ear barotrauma(气压伤).It occurs most often during steep ascents and descents and is usually associated with plane take⁃offs and landings,or driving up or down mountains.Most subway stations dont usually cause ear barotrauma,because they arent deep or steep enough for your ears to register a significant enough difference in air pressure.But taking the elevator to reach Chinas deepest subway station might actually clog up your ears.Thats because it is located 116 meters below the surface,which is the equivalent of about 40 floors underground.展开更多
Objective:To establish the Chinese population's amniotic fluid deepest vertical pocket(DVP)reference curves for dichorionic twin pregnancies and to investigate DVP links with adverse perinatal outcomes.Methods:Thi...Objective:To establish the Chinese population's amniotic fluid deepest vertical pocket(DVP)reference curves for dichorionic twin pregnancies and to investigate DVP links with adverse perinatal outcomes.Methods:This retrospective cohort study,conducted at Peking University Third Hospital from August 2011 to December 2020,used data from 375 women aged 20 to 45 years who had dichorionic twin pregnancies that were confirmed through first-trimester ultrasound.After exclusions,reference curves were developed using 318 women with 3,299 DVP scans,and the data analyzed included maternal demographics,pregnancy outcomes,ultrasound measurements,and neonatal information.DVPs were assessed via ultrasound at regular intervals and grouped by gestational age(GA)for analyses.Linear mixed models were used to create amniotic fluid reference curves.Associations between abnormalities and adverse perinatal outcomes were examined using Chi-squared or Fisher's exact tests.Logistic regression provided both crude and adjusted odds ratios,adjusting for pre-pregnancy weight,age,ethnicity,parity,and conception mode.Significance was set at P<0.05 with 95%confidence intervals(CI),and the analyses were conducted using SPSS ver.26.0(IBM Corp.,Armonk,NY)and SAS ver.9.4(SAS Institute Inc.,Cary,NC,USA)software.Results:DVP increased from the first trimester to a maximum at 26 weeks(95%confidence interval(CI),2.7–8.3 cm for twin 1 and 2.8–7.9 cm for twin 2)and then decreased gradually toward term.Differences between twins 1 and 2 were significant after 26 weeks(95%CI for twin 1:5.3,5.5;95%CI for twin 2:4.4,4.5;P<0.010).Polyhydramnios of twin 1 increased the risk of large for GA.Oligohydramnios of twin 1 increased the risk of small for GA.Polyhydramnios of twin 2 increased the risk of small for GA,premature birth,and neonatal complications.Oligohydramnios of twin 2 increased the risk of preeclampsia,hypertensive disorder complicating pregnancy,and premature rupture of membranes.Conclusion:Reference curves for twin amniotic fluid volumes vary by GA and differ between twins,with potential implications for pregnancy outcomes.展开更多
On February 20,2025,China National Petroleum Corporation announced that China's first ultra-deep scientific exploration well-Shenditake 1 Well-successfully reached a depth of 10910 m underground(Fig.1).Deep Earth ...On February 20,2025,China National Petroleum Corporation announced that China's first ultra-deep scientific exploration well-Shenditake 1 Well-successfully reached a depth of 10910 m underground(Fig.1).Deep Earth Towerke 1 Well is located in the heart of the Taklamakan Desert in the Xinjiang Uyghur Autonomous Region,within the territory of Shaya County.It has become the deepest vertical well in Asia and the second deepest in the world.The well has successively set five major engineering records:The deepest global tailpipe cementing,the deepest global cable imaging logging,the fastest global onshore drilling to exceed 10000 m,the deepest direct well drilling in Asia,and the deepest onshore coring in Asia.This marks another major breakthrough for China in the field of“Deep Earth”exploration,following its achievements in“Deep Space”and“Deep Sea.”展开更多
基金supported by the National Science Foundation of China (grant No.1374052)
文摘Objective In order to reduce the interfering noise from the earth surface, scientists have carried out multi-geophysical borehole observations and the related study. This study aims at improving signal-to-noise ratio obtained from the observation data to obtain zero noise data, which will be of great help to improve geophysical studies. Insights from this study will be significant for the earthquake disaster reduction, resource exploration and environmental protection.
文摘The Hongyancun subway station in Chongqing,China,is 116 meters deep and the difference in air pressure often leaves users with clogged(堵塞的)ears when accessed via its elevator.When the air pressure outside the eardrum(耳膜)becomes different than the pressure inside,you experience ear barotrauma(气压伤).It occurs most often during steep ascents and descents and is usually associated with plane take⁃offs and landings,or driving up or down mountains.Most subway stations dont usually cause ear barotrauma,because they arent deep or steep enough for your ears to register a significant enough difference in air pressure.But taking the elevator to reach Chinas deepest subway station might actually clog up your ears.Thats because it is located 116 meters below the surface,which is the equivalent of about 40 floors underground.
基金supported by Beijing Municipal Science&Technology Commission (Z201100005520074)Peking University Third Hospital (BYSYDL2021004)National Clinical Research Center for Obstetrics and Gynecology (BYSYSZKF2021003).
文摘Objective:To establish the Chinese population's amniotic fluid deepest vertical pocket(DVP)reference curves for dichorionic twin pregnancies and to investigate DVP links with adverse perinatal outcomes.Methods:This retrospective cohort study,conducted at Peking University Third Hospital from August 2011 to December 2020,used data from 375 women aged 20 to 45 years who had dichorionic twin pregnancies that were confirmed through first-trimester ultrasound.After exclusions,reference curves were developed using 318 women with 3,299 DVP scans,and the data analyzed included maternal demographics,pregnancy outcomes,ultrasound measurements,and neonatal information.DVPs were assessed via ultrasound at regular intervals and grouped by gestational age(GA)for analyses.Linear mixed models were used to create amniotic fluid reference curves.Associations between abnormalities and adverse perinatal outcomes were examined using Chi-squared or Fisher's exact tests.Logistic regression provided both crude and adjusted odds ratios,adjusting for pre-pregnancy weight,age,ethnicity,parity,and conception mode.Significance was set at P<0.05 with 95%confidence intervals(CI),and the analyses were conducted using SPSS ver.26.0(IBM Corp.,Armonk,NY)and SAS ver.9.4(SAS Institute Inc.,Cary,NC,USA)software.Results:DVP increased from the first trimester to a maximum at 26 weeks(95%confidence interval(CI),2.7–8.3 cm for twin 1 and 2.8–7.9 cm for twin 2)and then decreased gradually toward term.Differences between twins 1 and 2 were significant after 26 weeks(95%CI for twin 1:5.3,5.5;95%CI for twin 2:4.4,4.5;P<0.010).Polyhydramnios of twin 1 increased the risk of large for GA.Oligohydramnios of twin 1 increased the risk of small for GA.Polyhydramnios of twin 2 increased the risk of small for GA,premature birth,and neonatal complications.Oligohydramnios of twin 2 increased the risk of preeclampsia,hypertensive disorder complicating pregnancy,and premature rupture of membranes.Conclusion:Reference curves for twin amniotic fluid volumes vary by GA and differ between twins,with potential implications for pregnancy outcomes.
文摘On February 20,2025,China National Petroleum Corporation announced that China's first ultra-deep scientific exploration well-Shenditake 1 Well-successfully reached a depth of 10910 m underground(Fig.1).Deep Earth Towerke 1 Well is located in the heart of the Taklamakan Desert in the Xinjiang Uyghur Autonomous Region,within the territory of Shaya County.It has become the deepest vertical well in Asia and the second deepest in the world.The well has successively set five major engineering records:The deepest global tailpipe cementing,the deepest global cable imaging logging,the fastest global onshore drilling to exceed 10000 m,the deepest direct well drilling in Asia,and the deepest onshore coring in Asia.This marks another major breakthrough for China in the field of“Deep Earth”exploration,following its achievements in“Deep Space”and“Deep Sea.”
