The degradation of permafrost stability in China over the past 30 years is evaluated using a new, high-resolution near-surface air temperature reanalysis dataset. Results show that the permafrost extent clearly decrea...The degradation of permafrost stability in China over the past 30 years is evaluated using a new, high-resolution near-surface air temperature reanalysis dataset. Results show that the permafrost extent clearly decreased by 22% from 1980 to 2010, that is, a loss of 12.68×10^4 km^2. The degradation occurred not only in the transition regions between permafrost and seasonally frozen ground, but also and more importantly, in the interior of the permafrost regions. The deg-radation in the interior of permafrost regions accounted for 87% of the total degraded areas. The degradation occurred mainly during the 1980s to 1990s in the northeast permafrost area and the Qilian Mountains, and during the 1990s to 2000s in most areas of the Qinghai-Tibet Plateau （QTP）. This degradation will have systemic impacts on engineered infra-structures in permafrost regions, the water balance, and the global carbon budget. A more robust physical model should be used to evaluate the permafrost thermal stability at finer resolution in the future.展开更多
Quantum Physics (QP) was invented in the early years of the Twentieth century by physicists born and educated in the western world. We examine the possibility that this is the main reason—or at least one of the main ...Quantum Physics (QP) was invented in the early years of the Twentieth century by physicists born and educated in the western world. We examine the possibility that this is the main reason—or at least one of the main reasons—which caused QP to go astray from the start. We present the ABC for a renovated Quantum Physics.展开更多
为深入了解bGDGTs化合物对温度的响应是否受季节性变化和pH差异的影响,我们对中国多个偏碱性土壤bGDGTs化合物进行为期一年的观测.研究结果表明:在一年内,bGDGTs的组成对温度的响应是长期积累的结果,并不能反映短期(季节)的温度变化.寒...为深入了解bGDGTs化合物对温度的响应是否受季节性变化和pH差异的影响,我们对中国多个偏碱性土壤bGDGTs化合物进行为期一年的观测.研究结果表明:在一年内,bGDGTs的组成对温度的响应是长期积累的结果,并不能反映短期(季节)的温度变化.寒冷的青藏高原高海拔地区b GDGTs指标可能反映了春季/夏季过渡阶段的温度;而其他区域bGDGTs的分布和指标均未呈现明显的季节性特征.土壤pH是造成不同校正公式斜率差异的最主要原因,不同pH条件下,MBT指标对温度的响应存在显著差异.在中国中性-偏碱性土壤中,MBT指标与年均大气温度MAAT(5~25?C)的关系为:MAAT=20.78×MBT+5.92(R2=0.88, p <0.001).该校正公式在中性-偏碱性土壤环境中比之前的MBT-MAAT校正公式更精确,为反演中国区域古温度提供理论依据.展开更多
基金supported by National Natural Science Foundation of China Projects (No. 41471359)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No. 2016375)the Chinese Academy of Sciences Action Plan for West Development Project "Remote Sensing Data Products in the Heihe River Basin: Algorithm Development, Data Products Generation and Application Experiments" (No. KZCX2-XB3-15)
文摘The degradation of permafrost stability in China over the past 30 years is evaluated using a new, high-resolution near-surface air temperature reanalysis dataset. Results show that the permafrost extent clearly decreased by 22% from 1980 to 2010, that is, a loss of 12.68×10^4 km^2. The degradation occurred not only in the transition regions between permafrost and seasonally frozen ground, but also and more importantly, in the interior of the permafrost regions. The deg-radation in the interior of permafrost regions accounted for 87% of the total degraded areas. The degradation occurred mainly during the 1980s to 1990s in the northeast permafrost area and the Qilian Mountains, and during the 1990s to 2000s in most areas of the Qinghai-Tibet Plateau （QTP）. This degradation will have systemic impacts on engineered infra-structures in permafrost regions, the water balance, and the global carbon budget. A more robust physical model should be used to evaluate the permafrost thermal stability at finer resolution in the future.
文摘Quantum Physics (QP) was invented in the early years of the Twentieth century by physicists born and educated in the western world. We examine the possibility that this is the main reason—or at least one of the main reasons—which caused QP to go astray from the start. We present the ABC for a renovated Quantum Physics.
文摘为深入了解bGDGTs化合物对温度的响应是否受季节性变化和pH差异的影响,我们对中国多个偏碱性土壤bGDGTs化合物进行为期一年的观测.研究结果表明:在一年内,bGDGTs的组成对温度的响应是长期积累的结果,并不能反映短期(季节)的温度变化.寒冷的青藏高原高海拔地区b GDGTs指标可能反映了春季/夏季过渡阶段的温度;而其他区域bGDGTs的分布和指标均未呈现明显的季节性特征.土壤pH是造成不同校正公式斜率差异的最主要原因,不同pH条件下,MBT指标对温度的响应存在显著差异.在中国中性-偏碱性土壤中,MBT指标与年均大气温度MAAT(5~25?C)的关系为:MAAT=20.78×MBT+5.92(R2=0.88, p <0.001).该校正公式在中性-偏碱性土壤环境中比之前的MBT-MAAT校正公式更精确,为反演中国区域古温度提供理论依据.
