依托国家气象信息中心研发的省级多源融合实况分析系统,以逐小时和逐分钟的多要素站点数据为观测场,以ECWMF C1D预报数据为背景场,利用时空多尺度分析系统(The Space and Time Multiscale Analysis System,STMAS)开展产品生成试验。在...依托国家气象信息中心研发的省级多源融合实况分析系统,以逐小时和逐分钟的多要素站点数据为观测场,以ECWMF C1D预报数据为背景场,利用时空多尺度分析系统(The Space and Time Multiscale Analysis System,STMAS)开展产品生成试验。在对观测场进行质量控制和对背景场进行偏差订正的基础上,通过网格层数阈值参数和地面网格影响半径优化实验,构建针对温湿风多源资料的有效融合分析模型,实现内蒙古自治区逐小时、逐10 min的1 km分辨率的温湿风融合实况分析产品的生成,最后对2023年10—11月的融合实况分析产品与EC背景场和观测数据进行对比,评估融合实况分析产品的质量。结果表明:与EC背景场相比,各要素的融合实况分析产品与观测值具有更小的偏差、更小的均方根误差、更大的相关系数值;实况分析产品的评估指标在时间序列上也平稳低于EC背景场,在空间刻画上,与地面观测结果更为接近,能够体现出更多的小尺度信息;实况分析产品与赛区站点观测值非常接近,评估指标表现较好。内蒙古自治区1 km温湿风实况分析产品具有较高质量,能够满足实时业务需要,为第十四届全国冬季运动会观测、预报和服务提供数据支撑。展开更多
To further study the effect of sputtered Au film as transition electrode layer on the electrical properties and interface microstructures of Na20-PbO-Nb2O5-SiO2 multilayer glass-ceramic capacitors, Au films pre-deposi...To further study the effect of sputtered Au film as transition electrode layer on the electrical properties and interface microstructures of Na20-PbO-Nb2O5-SiO2 multilayer glass-ceramic capacitors, Au films pre-deposited at different time were prepared by DC magnetron sputtering. Compared with the single paste electrode structure, samples with Au films pre-deposited from 6 to 18 min have the consistent perfor- mance to effectively improve the electrical properties of the capacitors, resulting in the doubled breakdown strength, an increase of equivalent capacitance by 22% and a decrease of leakage current by an order of magnitude. SEM observations indicate that the Au films with deposition time from 6 to 18 min would all help the formation of a dense electrode/dielectric interface and inhibit the diffusion of Ag. The results reveal that Au film pre-deposited for 6 min as inner electrode was sufficient to improve the interface microstructure and therefore to inhibit the Ag diffusion and enhance the overall performance of the multi-layer glass-ceramic capacitors.展开更多
This paper proposes a method to ascertain the stability of two dimensional linear time invariant discrete system within the shifted unit circle which is represented by the form of characteristic equation. Further an e...This paper proposes a method to ascertain the stability of two dimensional linear time invariant discrete system within the shifted unit circle which is represented by the form of characteristic equation. Further an equivalent single dimensional characteristic equation is formed from the two dimensional characteristic equation then the stability formulation in the left half of Z-plane, where the roots of characteristic equation f(Z) = 0 should lie within the shifted unit circle. The coefficient of the unit shifted characteristic equation is suitably arranged in the form of matrix and the inner determinants are evaluated using proposed Jury’s concept. The proposed stability technique is simple and direct. It reduces the computational cost. An illustrative example shows the applicability of the proposed scheme.展开更多
The earthquakes with Ms≥6.0 are often gathered into belts or clusters and are roughly consistent with tectonic structure trends in the Sichuan-Yunnan (Chuan-Dian) region. The middle south part(98°-106°E, 21...The earthquakes with Ms≥6.0 are often gathered into belts or clusters and are roughly consistent with tectonic structure trends in the Sichuan-Yunnan (Chuan-Dian) region. The middle south part(98°-106°E, 21°-34°N) of South-North Seismic Zone can be zoned into seven small areas. There all were strong quakes with M_s≥7.0 historically in each small area. Ten earthquakes with M_s≥7.0 have occurred in this region since 1970 and they appeared in five small areas respectively. The relationships between occurrence-time and cumulative frequencies of strong quakes in these five areas are shown to be an exponential distribution or power function. By examining the inner coincidence it is indicated that these relationships are of definite significance to mid-long term macroseismic prediction of each area.展开更多
文摘依托国家气象信息中心研发的省级多源融合实况分析系统,以逐小时和逐分钟的多要素站点数据为观测场,以ECWMF C1D预报数据为背景场,利用时空多尺度分析系统(The Space and Time Multiscale Analysis System,STMAS)开展产品生成试验。在对观测场进行质量控制和对背景场进行偏差订正的基础上,通过网格层数阈值参数和地面网格影响半径优化实验,构建针对温湿风多源资料的有效融合分析模型,实现内蒙古自治区逐小时、逐10 min的1 km分辨率的温湿风融合实况分析产品的生成,最后对2023年10—11月的融合实况分析产品与EC背景场和观测数据进行对比,评估融合实况分析产品的质量。结果表明:与EC背景场相比,各要素的融合实况分析产品与观测值具有更小的偏差、更小的均方根误差、更大的相关系数值;实况分析产品的评估指标在时间序列上也平稳低于EC背景场,在空间刻画上,与地面观测结果更为接近,能够体现出更多的小尺度信息;实况分析产品与赛区站点观测值非常接近,评估指标表现较好。内蒙古自治区1 km温湿风实况分析产品具有较高质量,能够满足实时业务需要,为第十四届全国冬季运动会观测、预报和服务提供数据支撑。
基金financially supported by the National High Technical Research and Development Programme of China (No.2008AA03A236)
文摘To further study the effect of sputtered Au film as transition electrode layer on the electrical properties and interface microstructures of Na20-PbO-Nb2O5-SiO2 multilayer glass-ceramic capacitors, Au films pre-deposited at different time were prepared by DC magnetron sputtering. Compared with the single paste electrode structure, samples with Au films pre-deposited from 6 to 18 min have the consistent perfor- mance to effectively improve the electrical properties of the capacitors, resulting in the doubled breakdown strength, an increase of equivalent capacitance by 22% and a decrease of leakage current by an order of magnitude. SEM observations indicate that the Au films with deposition time from 6 to 18 min would all help the formation of a dense electrode/dielectric interface and inhibit the diffusion of Ag. The results reveal that Au film pre-deposited for 6 min as inner electrode was sufficient to improve the interface microstructure and therefore to inhibit the Ag diffusion and enhance the overall performance of the multi-layer glass-ceramic capacitors.
文摘This paper proposes a method to ascertain the stability of two dimensional linear time invariant discrete system within the shifted unit circle which is represented by the form of characteristic equation. Further an equivalent single dimensional characteristic equation is formed from the two dimensional characteristic equation then the stability formulation in the left half of Z-plane, where the roots of characteristic equation f(Z) = 0 should lie within the shifted unit circle. The coefficient of the unit shifted characteristic equation is suitably arranged in the form of matrix and the inner determinants are evaluated using proposed Jury’s concept. The proposed stability technique is simple and direct. It reduces the computational cost. An illustrative example shows the applicability of the proposed scheme.
文摘The earthquakes with Ms≥6.0 are often gathered into belts or clusters and are roughly consistent with tectonic structure trends in the Sichuan-Yunnan (Chuan-Dian) region. The middle south part(98°-106°E, 21°-34°N) of South-North Seismic Zone can be zoned into seven small areas. There all were strong quakes with M_s≥7.0 historically in each small area. Ten earthquakes with M_s≥7.0 have occurred in this region since 1970 and they appeared in five small areas respectively. The relationships between occurrence-time and cumulative frequencies of strong quakes in these five areas are shown to be an exponential distribution or power function. By examining the inner coincidence it is indicated that these relationships are of definite significance to mid-long term macroseismic prediction of each area.
