After the establishment of the seismic observation network of southern Okinawa in August,1988 by the JMA(Japan Meteorological Agency),many hypocenters of earthquakes have been located.However,due to the small number o...After the establishment of the seismic observation network of southern Okinawa in August,1988 by the JMA(Japan Meteorological Agency),many hypocenters of earthquakes have been located.However,due to the small number of observation stations and narrow configuration of the array,the hypocenters lo-cated contain some systematic errors.Numerical experiments on the extent of the errors and the reliabilityof the JMA seismic observation network showed that the obtained hypocenters deeper than 100 km werereliable,but that for the obtained hypocenters shallower than 100 km,only the epicenters were reliable.展开更多
Impact-based forecasts and risk-based warnings are the key approach to reduce disasters caused by tropical cyclones(TCs). This review paper highlights Japan Meteorological Agency's and RSMC Tokyo – Typhoon Center...Impact-based forecasts and risk-based warnings are the key approach to reduce disasters caused by tropical cyclones(TCs). This review paper highlights Japan Meteorological Agency's and RSMC Tokyo – Typhoon Center's development and eff orts to operationalization of various TC observation, analysis and numerical weather prediction(NWP) techniques, which are the fundamental basis of the approach.TC monitoring has been carried out with geostationary satellites named Himawari series since 1978. Since 2015 the fi rst new generation satellite Himawari-8 has established new era of the TC monitoring at a high resolution and frequency. In addition, space-borne microwave instruments have provided many hydrological properties around TC.As for ground based observation, radar is a powerful tool to investigate the TC structure characterized by rain distribution and wind fi elds. A phased-array radar gives us the vivid pictures of individual cumulonimbus with its quick scan ability.RSMC-Tokyo uses the Himawari-8/9 images, atmospheric motion vectors(AMVs), space-borne microwave images, sea surface winds of scatterometer, and ground-based radar wind observation for the TC intensity analysis. For NWP, many eff orts have been put into new assimilation schemes, high-resolution models and combined atmosphere-ocean models. Ensemble based analysis and forecast system are considered to be eff ective to estimate the uncertainty of the TC forecasts.展开更多
采用水热法,利用乙醇和水的混合溶剂合成了单分散钛酸锶纳米晶体。X射线衍射(XRD)结果显示该晶体为立方相,延长反应时间其结晶性增强。扫描电子显微镜(SEM)、透射电子显微镜(TEM)结果显示样品为70 nm左右的均匀立方块晶体。利用SEM、TE...采用水热法,利用乙醇和水的混合溶剂合成了单分散钛酸锶纳米晶体。X射线衍射(XRD)结果显示该晶体为立方相,延长反应时间其结晶性增强。扫描电子显微镜(SEM)、透射电子显微镜(TEM)结果显示样品为70 nm左右的均匀立方块晶体。利用SEM、TEM、高分辨透射电子显微镜(HRTEM)和电子衍射(ED)谱研究了该纳米晶体的生长过程,结果表明:前驱体经过扩散反应生成钛酸锶晶核,晶核之间由于定向生长作用而团聚连接形成颗粒球,最后颗粒球在缓慢的奥斯特瓦尔德熟化作用下转化为钛酸锶晶体。这一"扩散反应、定向生长、奥斯特瓦尔德熟化"的生长过程揭示了钛酸锶纳米晶体的生长机理。利用Johnson-MehlAvrami(JMA)方程模拟证实了其初始阶段的扩散反应机理,并得出反应活化能为15.79 k J·mol-1。展开更多
文摘After the establishment of the seismic observation network of southern Okinawa in August,1988 by the JMA(Japan Meteorological Agency),many hypocenters of earthquakes have been located.However,due to the small number of observation stations and narrow configuration of the array,the hypocenters lo-cated contain some systematic errors.Numerical experiments on the extent of the errors and the reliabilityof the JMA seismic observation network showed that the obtained hypocenters deeper than 100 km werereliable,but that for the obtained hypocenters shallower than 100 km,only the epicenters were reliable.
文摘Impact-based forecasts and risk-based warnings are the key approach to reduce disasters caused by tropical cyclones(TCs). This review paper highlights Japan Meteorological Agency's and RSMC Tokyo – Typhoon Center's development and eff orts to operationalization of various TC observation, analysis and numerical weather prediction(NWP) techniques, which are the fundamental basis of the approach.TC monitoring has been carried out with geostationary satellites named Himawari series since 1978. Since 2015 the fi rst new generation satellite Himawari-8 has established new era of the TC monitoring at a high resolution and frequency. In addition, space-borne microwave instruments have provided many hydrological properties around TC.As for ground based observation, radar is a powerful tool to investigate the TC structure characterized by rain distribution and wind fi elds. A phased-array radar gives us the vivid pictures of individual cumulonimbus with its quick scan ability.RSMC-Tokyo uses the Himawari-8/9 images, atmospheric motion vectors(AMVs), space-borne microwave images, sea surface winds of scatterometer, and ground-based radar wind observation for the TC intensity analysis. For NWP, many eff orts have been put into new assimilation schemes, high-resolution models and combined atmosphere-ocean models. Ensemble based analysis and forecast system are considered to be eff ective to estimate the uncertainty of the TC forecasts.
文摘采用水热法,利用乙醇和水的混合溶剂合成了单分散钛酸锶纳米晶体。X射线衍射(XRD)结果显示该晶体为立方相,延长反应时间其结晶性增强。扫描电子显微镜(SEM)、透射电子显微镜(TEM)结果显示样品为70 nm左右的均匀立方块晶体。利用SEM、TEM、高分辨透射电子显微镜(HRTEM)和电子衍射(ED)谱研究了该纳米晶体的生长过程,结果表明:前驱体经过扩散反应生成钛酸锶晶核,晶核之间由于定向生长作用而团聚连接形成颗粒球,最后颗粒球在缓慢的奥斯特瓦尔德熟化作用下转化为钛酸锶晶体。这一"扩散反应、定向生长、奥斯特瓦尔德熟化"的生长过程揭示了钛酸锶纳米晶体的生长机理。利用Johnson-MehlAvrami(JMA)方程模拟证实了其初始阶段的扩散反应机理,并得出反应活化能为15.79 k J·mol-1。
