利用河南濮阳CINRDA/SB多普勒雷达探测资料,结合常规天气图资料、地面自动站资料等,对2011年7月10日发生在河南濮阳的下击暴流天气进行诊断分析。分析表明:此次下击暴流天气以高空快速下滑的低压槽为背景,高空冷空气叠加在低空暖舌之上...利用河南濮阳CINRDA/SB多普勒雷达探测资料,结合常规天气图资料、地面自动站资料等,对2011年7月10日发生在河南濮阳的下击暴流天气进行诊断分析。分析表明:此次下击暴流天气以高空快速下滑的低压槽为背景,高空冷空气叠加在低空暖舌之上,使大气具有强烈的层结不稳定。大气环境场呈倒"V"形的垂直温湿分布:云底位于700 h Pa高度,云底以下空气干燥,气温直减率约为9℃/km,接近干绝热气温直减率,有利于干下击暴流的发生。地面辐合线的存在和弱冷空气的侵袭,为强风暴单体的产生提供了动力抬升条件。从多普勒雷达产品上看,风暴初始回波发生在一条稳定的晴空窄带回波上,通过单体间的合并加强,发展成为孤立的多单体强风暴;风暴反射率因子反复在3—6 km高度强烈发展,风暴反射率因子强核高度反复4次快速下降,形成强烈的冷下沉气流,在底层出现强烈的径向辐散风;径向速度图上中层一直存在向着反射率因子核心的辐合特征,这正是下击暴流的风场特征。展开更多
We developed an integrated microfluidic chip for long-term culture of isolated single cells. This polydimethylsiloxane (PDMS) based device could accurately seed each single cell into different culture chambers, and is...We developed an integrated microfluidic chip for long-term culture of isolated single cells. This polydimethylsiloxane (PDMS) based device could accurately seed each single cell into different culture chambers, and isolate one chamber from each other with monolithically integrated pneumatic valves. We optimized the culture conditions, including the frequency of medium replacement and the introduction of conditioned medium, to keep the single cells alive for 4 days. We cultured a few hundred cells in a separated chamber on the same chip to continuously supply the conditioned medium into the culture chambers for single cells. This approach greatly facilitated the growth of single cells, and created a suitable microenvironment for observing cells' autonomous process in situ without the interference of other adjacent cells. This single cell colony assay is expandable to higher throughput, fitting the needs in the studies of drug screening and stem cell differentiation.展开更多
文摘利用河南濮阳CINRDA/SB多普勒雷达探测资料,结合常规天气图资料、地面自动站资料等,对2011年7月10日发生在河南濮阳的下击暴流天气进行诊断分析。分析表明:此次下击暴流天气以高空快速下滑的低压槽为背景,高空冷空气叠加在低空暖舌之上,使大气具有强烈的层结不稳定。大气环境场呈倒"V"形的垂直温湿分布:云底位于700 h Pa高度,云底以下空气干燥,气温直减率约为9℃/km,接近干绝热气温直减率,有利于干下击暴流的发生。地面辐合线的存在和弱冷空气的侵袭,为强风暴单体的产生提供了动力抬升条件。从多普勒雷达产品上看,风暴初始回波发生在一条稳定的晴空窄带回波上,通过单体间的合并加强,发展成为孤立的多单体强风暴;风暴反射率因子反复在3—6 km高度强烈发展,风暴反射率因子强核高度反复4次快速下降,形成强烈的冷下沉气流,在底层出现强烈的径向辐散风;径向速度图上中层一直存在向着反射率因子核心的辐合特征,这正是下击暴流的风场特征。
基金supported by the National Natural Science Foundation of China (20733001, 20890020, 90913011, 20905004)the Ministry of Science and Technology of China (2011CB809106)+1 种基金the Ministry of Education of Chinathe Fok Ying Tung Education Foundation
文摘We developed an integrated microfluidic chip for long-term culture of isolated single cells. This polydimethylsiloxane (PDMS) based device could accurately seed each single cell into different culture chambers, and isolate one chamber from each other with monolithically integrated pneumatic valves. We optimized the culture conditions, including the frequency of medium replacement and the introduction of conditioned medium, to keep the single cells alive for 4 days. We cultured a few hundred cells in a separated chamber on the same chip to continuously supply the conditioned medium into the culture chambers for single cells. This approach greatly facilitated the growth of single cells, and created a suitable microenvironment for observing cells' autonomous process in situ without the interference of other adjacent cells. This single cell colony assay is expandable to higher throughput, fitting the needs in the studies of drug screening and stem cell differentiation.
