Global warming caused by elevated carbon dioxide(CO2)is a major environmental and policy issue.The current global average temperature has been elevated by 1℃since the industrial revolution,and it is likely to reach a...Global warming caused by elevated carbon dioxide(CO2)is a major environmental and policy issue.The current global average temperature has been elevated by 1℃since the industrial revolution,and it is likely to reach a temperature increase of 1.5℃between 2030 and 2052(IPCC 2018).Human-caused emission of CO2 is responsible for the greenhouse effect and the atmospheric CO2 concentration is higher now than at any other time in the past 500000 years,and it continues to rise(Lüthi et al.2008).Impacts of arthropod-plant interactions on carbon dynamics and the global climate are important but often ignored.For example,outbreaks of the mountain pine beetle,Dendroctonus ponderosae,in British Columbia during 2000-2020 will cause the release of an estimated 270 Mt carbon and convert the forest from a small carbon sink to a large carbon source(Kurz et al.2008).The annual carbon release due to outbreaks of this beetle is almost equivalent to the annual carbon emission from all forest fires occurring in Canada over 1959-1999(Kurz et al.2008).展开更多
This study involved outcrop,drilling,seismic,gravity,and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea(PSCS)and establish its evolution model.The re...This study involved outcrop,drilling,seismic,gravity,and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea(PSCS)and establish its evolution model.The results indicate that a series of arc-shaped ophiolite belts and calcalkaline magmatic rocks are developed in northern Borneo,both of which have the characteristics of gradually changing younger from west to east,and are direct signs of subduction and collision of PSCS.At the same time,the subduction of PSCS led to the formation of three accretion zones from the south to the north in Borneo,the Kuching belt,Sibu belt,and Miri belt.The sedimentary formation of northern Borneo is characterized by a three-layer structure,with the oceanic basement at the bottom,overlying the deep-sea flysch deposits of the Rajang–Crocker group,and the molasse sedimentary sequence that is dominated by river-delta and shallow marine facies at the top,recording the whole subduction–collision–orogeny process of PSCS.Further,seismic reflection and tomography also confirmed the subduction and collision of PSCS.Based on the geological records of the subduction and collision of PSCS,combined with the comprehensive analysis of segmented expansion and key tectonic events in the South China Sea,we establish the“gradual”subduction-collision evolution model of PSCS.During the late Eocene to middle Miocene,the Zengmu,Nansha,and Liyue–Palawan blocks were separated by West Baram Line and Balabac Fault,which collided with the Borneo block and Kagayan Ridge successively from the west to the east,forming several foreland basin systems,and PSCS subducted and closed from the west to the east.The subduction and extinction of PSCS controlled the oil and gas distribution pattern of southern South China Sea(SSCS)mainly in three aspects.First,the“gradual”closure process of PSCS led to the continuous development of many large deltas in SSCS.Second,the deltas formed during the subduction–collision of PSCS controlled the development of source rocks in the basins of SSCS.Macroscopically,the distribution and scale of deltas controlled the distribution and scale of source rocks,forming two types of source rocks,namely,coal measures and terrestrial marine facies.Microscopically,the difference of terrestrial higher plants carried by the delta controlled the proportion of macerals of source rocks.Third,the difference of source rocks mainly controlled the distribution pattern of oil and gas in SSCS.Meanwhile,the difference in the scale of source rocks mainly controlled the difference in the amount of oil and gas discoveries,resulting in a huge amount of oil and gas discoveries in the basin of SSCS.Meanwhile,the difference of macerals of source rocks mainly controlled the difference of oil and gas generation,forming the oil and gas distribution pattern of“nearshore oil and far-shore gas”.展开更多
Background: Snakebite envenomation in pregnancy is uncommon. It can lead to a poor outcome in both the mother and the fetus. We describe our approach to envenomation in pregnancy based on the currently available evide...Background: Snakebite envenomation in pregnancy is uncommon. It can lead to a poor outcome in both the mother and the fetus. We describe our approach to envenomation in pregnancy based on the currently available evidence. Case: We reported two case of snakebite in the third trimester of pregnancy having caused placental abruption with expelling a fresh still born baby and a live baby. In both cases, consumption coagulopathy occurred. managed by polyvalent anti-snake and blood transfusion. Their investigations became normal and they were discharged of hospitalization. Conclusion: Snakebite envenomation in pregnant is a maternal and fetal emergency. Treatment must be quick and well adapted.展开更多
Introduction: Gastroschisis is one of the neonatal pathologies with bad prognosis in developing countries due to a lack of equipment. We aim to report one way of managing this malformation that could be practised ever...Introduction: Gastroschisis is one of the neonatal pathologies with bad prognosis in developing countries due to a lack of equipment. We aim to report one way of managing this malformation that could be practised everywhere, constituting an alternative approach to surgery in poor areas. Patients and Methods: This observational and descriptive study included newborn babies with gastroschisis who underwent gradual bedside reduction at the Paediatric Surgery Department of the Yaounde Central Hospital. Results: Our cohort was constituted by 32 newborn babies with a mean age of 18.12 hours on admission. The Lefort type 2 was the most frequent in 81.25% of cases. The mean time for oral feeding after complete reduction was 17.4 days and the duration of hospital stay was 24.91 days. Survival rates were at 40.63%, with a residual hernia after healing in 38.46% of cases. Conclusion: Despite the high rate of mortality, gradual reduction of gastroschisis at the bedside seems to be an opportunity for resource constrained areas and can be an alternative solution to surgery.展开更多
Studying the abrupt change of winter temperature(ACWT)over the Mongolian Plateau(MP,including Inner Mongolia Autonomous Region and State of Mongolia)is of great significance for understanding the spatiotemporal distri...Studying the abrupt change of winter temperature(ACWT)over the Mongolian Plateau(MP,including Inner Mongolia Autonomous Region and State of Mongolia)is of great significance for understanding the spatiotemporal distribution of temperature and the mechanism of global climate change.Monthly temperature data during 1961–2017was collected,and the abrupt change point was determined by the Mann–Kendall test and sliding ttest,to analyze the characteristics and causes of ACWT.The results showed that(a)The winter temperature has rapidly increased with a trend of 0.41℃/10a,which was significantly higher than that of the rest area of Chinese mainland,indicating that climate change in the MP was more sensitive to global warming.(b)The abrupt change point occurred in 1988,with temperature of-15.5℃and-14.1℃before and after abrupt change,respectively.The ACWT in 50°N was 1–3 years later than that in 40°N,and the isotherms of different temperatures moved northward by 10–200 km,especially-16℃isotherms moved approximately 200 km northward after 1988.(c)The Arctic Oscillation(AO)and Mongolian High(MH)anomaly affects winter temperature over the MP.When the AO is unusually strong,the MH and East Asian winter monsoon are weak,and southerly winds prevail in most regions,which is not conducive to the cold air developing southward,leading to higher winter temperature in the MP.Overwise,abnormally northerly winds prevail and temperature is low.Meanwhile,the abrupt change time of AO occurred in 1987 before winter temperature.It shows that the AO indirectly causes winter temperatures to rise by influencing the MH and is also the main driving factor of ACWT.展开更多
新型配电网分布式电源(Distributed Generation,DG)引起的低压侧电压波动是影响用户电能质量的关键因素。文中针对新型配电网的电压调节问题,在电网无功充足的条件下,提出了一种基于有载调压变压器(On-load Tap Changer,OLTC)与模块化...新型配电网分布式电源(Distributed Generation,DG)引起的低压侧电压波动是影响用户电能质量的关键因素。文中针对新型配电网的电压调节问题,在电网无功充足的条件下,提出了一种基于有载调压变压器(On-load Tap Changer,OLTC)与模块化配电变压器(Modular Distribution Transformer,MDT)的分层逐级协同调压策略。该策略首先提出电压断面质量这一概念并给出不同情况的建模方法,然后将电压波动范围分为三个区间:区间1为正常区间、区间2为轻微越限区间、区间3为严重越限区间。考虑到经济性和MDT的快响应性,策略将MDT作为主要调节方式,OLTC作为后备调节手段。最后通过仿真对比不同策略下的调节效果,验证了所提策略的合理性。展开更多
全新世发生了一系列的亚洲季风突变事件,其中距今9.2ka的弱季风事件较少受到关注,其存在与否以及成因机制仍然存在争议。本文利用通用地球系统模式(Community Earth SystemModel,CESM)进行全新世以来瞬变积分气候模拟试验得到的结果(Nan...全新世发生了一系列的亚洲季风突变事件,其中距今9.2ka的弱季风事件较少受到关注,其存在与否以及成因机制仍然存在争议。本文利用通用地球系统模式(Community Earth SystemModel,CESM)进行全新世以来瞬变积分气候模拟试验得到的结果(NanjingNormalUniversity-12ka,NNU-12ka)对比重建资料和国际上已完成的过去21ka以来的瞬变积分模拟试验(Transient Climate Evolution over the last 21000 years,TraCE-21ka),探究了9.2ka亚洲弱季风事件的时空特征及其成因。结果表明:NNU-12ka太阳活动敏感性试验模拟出了9.6~9.4ka前后的亚洲弱季风事件,此时总太阳辐射减少了0.38Wm^(2),亚洲季风区夏季平均降水减少了0.17mmd^(-1)。而基于TraCE-21ka的全强迫试验结果表明,冰川融水和冰盖变化对该时期亚洲季风变化没有显著影响。NNU-12ka太阳活动试验中亚洲热带季风区夏季降水减少尤为明显,在我国东北地区降水略有增加。热带季风减弱的原因是由于太阳辐射的骤降导致亚洲海陆热力梯度减弱,加强亚洲陆地的海平面气压,引起热带季风区的异常下沉运动,抑制水汽向亚洲季风区输送,进而通过动力作用减弱季风。展开更多
基金supported by the National Genetically Modified Organisms Breeding Major Project of China(2016ZX08012-005)the National Key R&D Program of China(2017YFD0200400)the National Natural Science Foundation of China(31572003)。
文摘Global warming caused by elevated carbon dioxide(CO2)is a major environmental and policy issue.The current global average temperature has been elevated by 1℃since the industrial revolution,and it is likely to reach a temperature increase of 1.5℃between 2030 and 2052(IPCC 2018).Human-caused emission of CO2 is responsible for the greenhouse effect and the atmospheric CO2 concentration is higher now than at any other time in the past 500000 years,and it continues to rise(Lüthi et al.2008).Impacts of arthropod-plant interactions on carbon dynamics and the global climate are important but often ignored.For example,outbreaks of the mountain pine beetle,Dendroctonus ponderosae,in British Columbia during 2000-2020 will cause the release of an estimated 270 Mt carbon and convert the forest from a small carbon sink to a large carbon source(Kurz et al.2008).The annual carbon release due to outbreaks of this beetle is almost equivalent to the annual carbon emission from all forest fires occurring in Canada over 1959-1999(Kurz et al.2008).
基金The National Natural Science Foundation of China under contract No.91528303the National Science and Technology Major Project under contract No.2016ZX05026-004the CNOOC Basic Geology and Exploration Strategy of Natural Gas in the South China Sea under contract No.2021-KT-YXKY-05。
文摘This study involved outcrop,drilling,seismic,gravity,and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea(PSCS)and establish its evolution model.The results indicate that a series of arc-shaped ophiolite belts and calcalkaline magmatic rocks are developed in northern Borneo,both of which have the characteristics of gradually changing younger from west to east,and are direct signs of subduction and collision of PSCS.At the same time,the subduction of PSCS led to the formation of three accretion zones from the south to the north in Borneo,the Kuching belt,Sibu belt,and Miri belt.The sedimentary formation of northern Borneo is characterized by a three-layer structure,with the oceanic basement at the bottom,overlying the deep-sea flysch deposits of the Rajang–Crocker group,and the molasse sedimentary sequence that is dominated by river-delta and shallow marine facies at the top,recording the whole subduction–collision–orogeny process of PSCS.Further,seismic reflection and tomography also confirmed the subduction and collision of PSCS.Based on the geological records of the subduction and collision of PSCS,combined with the comprehensive analysis of segmented expansion and key tectonic events in the South China Sea,we establish the“gradual”subduction-collision evolution model of PSCS.During the late Eocene to middle Miocene,the Zengmu,Nansha,and Liyue–Palawan blocks were separated by West Baram Line and Balabac Fault,which collided with the Borneo block and Kagayan Ridge successively from the west to the east,forming several foreland basin systems,and PSCS subducted and closed from the west to the east.The subduction and extinction of PSCS controlled the oil and gas distribution pattern of southern South China Sea(SSCS)mainly in three aspects.First,the“gradual”closure process of PSCS led to the continuous development of many large deltas in SSCS.Second,the deltas formed during the subduction–collision of PSCS controlled the development of source rocks in the basins of SSCS.Macroscopically,the distribution and scale of deltas controlled the distribution and scale of source rocks,forming two types of source rocks,namely,coal measures and terrestrial marine facies.Microscopically,the difference of terrestrial higher plants carried by the delta controlled the proportion of macerals of source rocks.Third,the difference of source rocks mainly controlled the distribution pattern of oil and gas in SSCS.Meanwhile,the difference in the scale of source rocks mainly controlled the difference in the amount of oil and gas discoveries,resulting in a huge amount of oil and gas discoveries in the basin of SSCS.Meanwhile,the difference of macerals of source rocks mainly controlled the difference of oil and gas generation,forming the oil and gas distribution pattern of“nearshore oil and far-shore gas”.
文摘Background: Snakebite envenomation in pregnancy is uncommon. It can lead to a poor outcome in both the mother and the fetus. We describe our approach to envenomation in pregnancy based on the currently available evidence. Case: We reported two case of snakebite in the third trimester of pregnancy having caused placental abruption with expelling a fresh still born baby and a live baby. In both cases, consumption coagulopathy occurred. managed by polyvalent anti-snake and blood transfusion. Their investigations became normal and they were discharged of hospitalization. Conclusion: Snakebite envenomation in pregnant is a maternal and fetal emergency. Treatment must be quick and well adapted.
文摘Introduction: Gastroschisis is one of the neonatal pathologies with bad prognosis in developing countries due to a lack of equipment. We aim to report one way of managing this malformation that could be practised everywhere, constituting an alternative approach to surgery in poor areas. Patients and Methods: This observational and descriptive study included newborn babies with gastroschisis who underwent gradual bedside reduction at the Paediatric Surgery Department of the Yaounde Central Hospital. Results: Our cohort was constituted by 32 newborn babies with a mean age of 18.12 hours on admission. The Lefort type 2 was the most frequent in 81.25% of cases. The mean time for oral feeding after complete reduction was 17.4 days and the duration of hospital stay was 24.91 days. Survival rates were at 40.63%, with a residual hernia after healing in 38.46% of cases. Conclusion: Despite the high rate of mortality, gradual reduction of gastroschisis at the bedside seems to be an opportunity for resource constrained areas and can be an alternative solution to surgery.
基金financially sponsored by the National Natural Science Foundation of China(41967052)the Graduate Students’Research&Innovation Fund of Inner Mongolia Normal University(CXJJS20117)the Graduate Education Innovation Program Funded Project of Inner Mongolia Autonomous Region(SZ2020119)。
文摘Studying the abrupt change of winter temperature(ACWT)over the Mongolian Plateau(MP,including Inner Mongolia Autonomous Region and State of Mongolia)is of great significance for understanding the spatiotemporal distribution of temperature and the mechanism of global climate change.Monthly temperature data during 1961–2017was collected,and the abrupt change point was determined by the Mann–Kendall test and sliding ttest,to analyze the characteristics and causes of ACWT.The results showed that(a)The winter temperature has rapidly increased with a trend of 0.41℃/10a,which was significantly higher than that of the rest area of Chinese mainland,indicating that climate change in the MP was more sensitive to global warming.(b)The abrupt change point occurred in 1988,with temperature of-15.5℃and-14.1℃before and after abrupt change,respectively.The ACWT in 50°N was 1–3 years later than that in 40°N,and the isotherms of different temperatures moved northward by 10–200 km,especially-16℃isotherms moved approximately 200 km northward after 1988.(c)The Arctic Oscillation(AO)and Mongolian High(MH)anomaly affects winter temperature over the MP.When the AO is unusually strong,the MH and East Asian winter monsoon are weak,and southerly winds prevail in most regions,which is not conducive to the cold air developing southward,leading to higher winter temperature in the MP.Overwise,abnormally northerly winds prevail and temperature is low.Meanwhile,the abrupt change time of AO occurred in 1987 before winter temperature.It shows that the AO indirectly causes winter temperatures to rise by influencing the MH and is also the main driving factor of ACWT.
文摘新型配电网分布式电源(Distributed Generation,DG)引起的低压侧电压波动是影响用户电能质量的关键因素。文中针对新型配电网的电压调节问题,在电网无功充足的条件下,提出了一种基于有载调压变压器(On-load Tap Changer,OLTC)与模块化配电变压器(Modular Distribution Transformer,MDT)的分层逐级协同调压策略。该策略首先提出电压断面质量这一概念并给出不同情况的建模方法,然后将电压波动范围分为三个区间:区间1为正常区间、区间2为轻微越限区间、区间3为严重越限区间。考虑到经济性和MDT的快响应性,策略将MDT作为主要调节方式,OLTC作为后备调节手段。最后通过仿真对比不同策略下的调节效果,验证了所提策略的合理性。
文摘全新世发生了一系列的亚洲季风突变事件,其中距今9.2ka的弱季风事件较少受到关注,其存在与否以及成因机制仍然存在争议。本文利用通用地球系统模式(Community Earth SystemModel,CESM)进行全新世以来瞬变积分气候模拟试验得到的结果(NanjingNormalUniversity-12ka,NNU-12ka)对比重建资料和国际上已完成的过去21ka以来的瞬变积分模拟试验(Transient Climate Evolution over the last 21000 years,TraCE-21ka),探究了9.2ka亚洲弱季风事件的时空特征及其成因。结果表明:NNU-12ka太阳活动敏感性试验模拟出了9.6~9.4ka前后的亚洲弱季风事件,此时总太阳辐射减少了0.38Wm^(2),亚洲季风区夏季平均降水减少了0.17mmd^(-1)。而基于TraCE-21ka的全强迫试验结果表明,冰川融水和冰盖变化对该时期亚洲季风变化没有显著影响。NNU-12ka太阳活动试验中亚洲热带季风区夏季降水减少尤为明显,在我国东北地区降水略有增加。热带季风减弱的原因是由于太阳辐射的骤降导致亚洲海陆热力梯度减弱,加强亚洲陆地的海平面气压,引起热带季风区的异常下沉运动,抑制水汽向亚洲季风区输送,进而通过动力作用减弱季风。
