This paper gives a description of the co-seismic and post-seismic groundwater level changes induced in Chinese mainland by the 2011 Mw9.0 Japan earthquake, and the corresponding stress changes calculated on the assump...This paper gives a description of the co-seismic and post-seismic groundwater level changes induced in Chinese mainland by the 2011 Mw9.0 Japan earthquake, and the corresponding stress changes calculated on the assumption of linear elasticity. The result shows that the main types of changes were oscillations and step increases. The North-South Seismic Belt and the Shanxi Seismic Belt were the main areas affected by the earthquake.展开更多
Several new demands have been put forward for the application of the Beijing continuous GNSS observations due to some particular reasons, such as the limited coverage of the observation network, the different construc...Several new demands have been put forward for the application of the Beijing continuous GNSS observations due to some particular reasons, such as the limited coverage of the observation network, the different construction and management criterion executed by different units and the intense interference resulting from human activity. In this paper, necessary processing of data is carried out, including more accurate calculation, corrections to the replacement, outliers and relocation of equipment, and elimination of linear trends in the E-component for every station. The E-components of the 16 available stations showed a lower sawtooth wave anomaly （slowly westward propagating） before the 2011 Tohoku Mw9. 0 earthquake, a coseismic step rebound （rapid eastward propagating） and a post-seismic D-shaped recovery. These steps constituted a complete earthquake process which was rarely seen before in the GNSS observations and provides a good example for further study. Moreover, the rapid eastward propagating during the earthquake is not influenced by the size of the given normal values, which may play a significant role in earthquake forecasting and early warning.展开更多
2011年3月11日日本东北部海域发生Mw9.0级特大地震,并诱发海啸.本文利用Centroid Moment Tensor(CMT)震源机制解作为震源项,以地震波传播理论为基础,基于横向各向同性PREM地球模型,考虑地表地形及海洋等地球特性,利用谱元法结合高性能...2011年3月11日日本东北部海域发生Mw9.0级特大地震,并诱发海啸.本文利用Centroid Moment Tensor(CMT)震源机制解作为震源项,以地震波传播理论为基础,基于横向各向同性PREM地球模型,考虑地表地形及海洋等地球特性,利用谱元法结合高性能并行计算,对日本大地震激发的地震波传播特性进行了数值模拟研究.计算结果显示了全球地震波的传播形态.将数值模拟结果与理论模型的走时曲线和实际观测数据进行拟合对比,验证了模拟结果的可靠性和可行性.分别就考虑海洋和不考虑海洋两种数值模型下的地震波传播特性进行了对比分析.结果显示,海洋的存在对地震波强地面运动存在明显的影响.海洋会使P波运动位移峰值和速度峰值相对较小;海洋对S波的影响较复杂,不考虑海洋效应时使得位移和波速随时间推移迅速减小.因此,对沿海地区的地震灾害评估应该考虑海洋效应.此外,考虑地球重力因素情况下,对数值计算得到的2004年印尼苏门答腊地震、2008年汶川地震及2011年日本福岛大地震激发的球型场和环型场特征进行对比研究,通过对功率谱密度结果的观察并与理论值的对比分析,可以清晰的看到三个大地震释放的能量有很明显的不同,同时认识到数值模拟结果可以较准确重现长周期理论频率值,主要表现在0T2～0T13的环型振型及0S7～0S31的球型振型.结果显示数值模拟方法可以成功的用于地球自由振荡研究,未来可以作为一个主要工具深入探讨地球的横向不均匀性等特性对地球自由振荡特性的影响.展开更多
Purpose:To assess clinical results of the 9 mW/5.4 J/cm^(2) accelerated crosslinking(ACXL)in the treatment of progressive keratoconus(KC)over a span of 5 years.Methods:The prospective open non-randomized interventiona...Purpose:To assess clinical results of the 9 mW/5.4 J/cm^(2) accelerated crosslinking(ACXL)in the treatment of progressive keratoconus(KC)over a span of 5 years.Methods:The prospective open non-randomized interventional study(Siena Eye-Cross Study 2)included 156 eyes of 112 patients with early progressive KC undergoing the Epi-Off 9 mW/5.4 J/cm^(2) ACXL at the Siena Crosslinking Centre,Italy.The mean age was 18.05±5.6 years.The 20-min treatments were performed using the New KXL I(Avedro,Waltham,USA),10 min of 0.1%HPMC Riboflavin soaking(VibeX Rapid,Avedro,Waltham,USA)and 10 min of continuous-light UV-A irradiation.Uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),Kmax,coma,minimum corneal thickness(MCT),surface asymmetry index(SAI),endothelial cell count(ECC)were measured,and corneal OCT performed.Results:UDVA and CDVA improved significantly at the 3rd(P=0.028),Δ+0.17 Snellen lines and 6th postoperative month,respectively(P<0.001),Δ+0.23 Snellen lines.Kmax improved at the 6th postoperative month(P=0.03),Δ−1.49 diopters from the baseline value.Also,coma aberration value improved significantly(P=0.004).A mild temporary haze was recorded in 14.77%of patients without affecting visual acuity and without persistent complications.Corneal OCT revealed a mean demarcation line depth at 332.6±33.6μm.Conclusion:The 5-year results of Epi-Off 9 mW/5.4 J/cm^(2) ACXL demonstrated statistically significant improvements in UCVA and CDVA,corneal curvature and corneal higher-order aberrations which confers a long-term stability for progressive ectasia.Based on the results of the Siena Eye-Cross Study 2,the 9 mW/5.4 J/cm^(2) ACXL is a candidate to be the natural evolution of Epi-Off CXL treatment for the management of early progressive corneal ectasia,and thus optimize clinic workflow.展开更多
基金suppvroted by the research grant from the Institute of Crustal Dynamics,China Earthquake Administration ( ZDJ2011-11)
文摘This paper gives a description of the co-seismic and post-seismic groundwater level changes induced in Chinese mainland by the 2011 Mw9.0 Japan earthquake, and the corresponding stress changes calculated on the assumption of linear elasticity. The result shows that the main types of changes were oscillations and step increases. The North-South Seismic Belt and the Shanxi Seismic Belt were the main areas affected by the earthquake.
基金funded by Research Foundation for Veteran Experts of China Earthquake Administration(201346)the Natural Science Foundation of Beijing Municipality(8041001,8092012)
文摘Several new demands have been put forward for the application of the Beijing continuous GNSS observations due to some particular reasons, such as the limited coverage of the observation network, the different construction and management criterion executed by different units and the intense interference resulting from human activity. In this paper, necessary processing of data is carried out, including more accurate calculation, corrections to the replacement, outliers and relocation of equipment, and elimination of linear trends in the E-component for every station. The E-components of the 16 available stations showed a lower sawtooth wave anomaly （slowly westward propagating） before the 2011 Tohoku Mw9. 0 earthquake, a coseismic step rebound （rapid eastward propagating） and a post-seismic D-shaped recovery. These steps constituted a complete earthquake process which was rarely seen before in the GNSS observations and provides a good example for further study. Moreover, the rapid eastward propagating during the earthquake is not influenced by the size of the given normal values, which may play a significant role in earthquake forecasting and early warning.
文摘2011年3月11日日本东北部海域发生Mw9.0级特大地震,并诱发海啸.本文利用Centroid Moment Tensor(CMT)震源机制解作为震源项,以地震波传播理论为基础,基于横向各向同性PREM地球模型,考虑地表地形及海洋等地球特性,利用谱元法结合高性能并行计算,对日本大地震激发的地震波传播特性进行了数值模拟研究.计算结果显示了全球地震波的传播形态.将数值模拟结果与理论模型的走时曲线和实际观测数据进行拟合对比,验证了模拟结果的可靠性和可行性.分别就考虑海洋和不考虑海洋两种数值模型下的地震波传播特性进行了对比分析.结果显示,海洋的存在对地震波强地面运动存在明显的影响.海洋会使P波运动位移峰值和速度峰值相对较小;海洋对S波的影响较复杂,不考虑海洋效应时使得位移和波速随时间推移迅速减小.因此,对沿海地区的地震灾害评估应该考虑海洋效应.此外,考虑地球重力因素情况下,对数值计算得到的2004年印尼苏门答腊地震、2008年汶川地震及2011年日本福岛大地震激发的球型场和环型场特征进行对比研究,通过对功率谱密度结果的观察并与理论值的对比分析,可以清晰的看到三个大地震释放的能量有很明显的不同,同时认识到数值模拟结果可以较准确重现长周期理论频率值,主要表现在0T2～0T13的环型振型及0S7～0S31的球型振型.结果显示数值模拟方法可以成功的用于地球自由振荡研究,未来可以作为一个主要工具深入探讨地球的横向不均匀性等特性对地球自由振荡特性的影响.
文摘Purpose:To assess clinical results of the 9 mW/5.4 J/cm^(2) accelerated crosslinking(ACXL)in the treatment of progressive keratoconus(KC)over a span of 5 years.Methods:The prospective open non-randomized interventional study(Siena Eye-Cross Study 2)included 156 eyes of 112 patients with early progressive KC undergoing the Epi-Off 9 mW/5.4 J/cm^(2) ACXL at the Siena Crosslinking Centre,Italy.The mean age was 18.05±5.6 years.The 20-min treatments were performed using the New KXL I(Avedro,Waltham,USA),10 min of 0.1%HPMC Riboflavin soaking(VibeX Rapid,Avedro,Waltham,USA)and 10 min of continuous-light UV-A irradiation.Uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),Kmax,coma,minimum corneal thickness(MCT),surface asymmetry index(SAI),endothelial cell count(ECC)were measured,and corneal OCT performed.Results:UDVA and CDVA improved significantly at the 3rd(P=0.028),Δ+0.17 Snellen lines and 6th postoperative month,respectively(P<0.001),Δ+0.23 Snellen lines.Kmax improved at the 6th postoperative month(P=0.03),Δ−1.49 diopters from the baseline value.Also,coma aberration value improved significantly(P=0.004).A mild temporary haze was recorded in 14.77%of patients without affecting visual acuity and without persistent complications.Corneal OCT revealed a mean demarcation line depth at 332.6±33.6μm.Conclusion:The 5-year results of Epi-Off 9 mW/5.4 J/cm^(2) ACXL demonstrated statistically significant improvements in UCVA and CDVA,corneal curvature and corneal higher-order aberrations which confers a long-term stability for progressive ectasia.Based on the results of the Siena Eye-Cross Study 2,the 9 mW/5.4 J/cm^(2) ACXL is a candidate to be the natural evolution of Epi-Off CXL treatment for the management of early progressive corneal ectasia,and thus optimize clinic workflow.
