本文基于三维区域空气质量模式WRF-Chem,通过修改模式化学模块,量化输出过程量和诊断量,提供了一种定量分析挥发性有机化合物(VOCs)源强不确定性对O_(3)生成影响的方法.为无法定量计算VOCs源强导致的臭氧生成率[P(O_(3))]偏差,以及由此...本文基于三维区域空气质量模式WRF-Chem,通过修改模式化学模块,量化输出过程量和诊断量,提供了一种定量分析挥发性有机化合物(VOCs)源强不确定性对O_(3)生成影响的方法.为无法定量计算VOCs源强导致的臭氧生成率[P(O_(3))]偏差,以及由此对O_(3)体积分数分布和污染控制相关联的VOCs敏感区和NOx敏感区分布的误判提供了方法参考.采用标准统计参数对WRF-Chem模式的气象场与污染场模拟性能进行了评估,相关指标均优于前人结果.以INTEX-B(intercontinental chemical transport experiment-phase B)人为源、FINNv1(fire inventory from NCAR version 1)生物质燃烧源和MEGAN(model of emissions of gases and aerosols from nature)生物源作为基准源,并以卫星观测数据作为约束,对排放源进行改进,评估了源改进前后臭氧生成率[P(O_(3))]、O_(3)体积分数和O_(3)控制敏感区指标(Ln/Q)的变化情况.仅人为VOCs(AVOCs)源增加68%后,P(O_(3))模拟峰值增升比例达13%~82%,以北京观测站点为例,P(O_(3))模拟月均峰值增加42%(22.5×10^(-9) h^(-1)).对P(O_(3))形成贡献比例最大的主要化学反应是HO2+NO(占比约68%),AVOCs源增加68%后,该反应贡献比例下降至65%.在改进源下,P(O_(3))普遍增加达到2×10^(-9)~4×10^(-9) h^(-1),O_(3)各季节增幅较大的区域均主要集中在京津冀、长三角和珠三角中心城市及周边区域,与我国大型城市区基本都是VOCs敏感区的结论一致.整体而言,VOCs源强改进后,NOx敏感区O_(3)体积分数增加幅度不大,不超过4×10^(-9),而部分VOCs敏感区增幅超过20×10^(-9).VOCs源强的不确定性会影响O_(3)形成过程中NOx和VOCs敏感区的判断,特别是VOCs源强明显低估会夸大VOCs敏感区的范围,从而降低O_(3)调控对策的有效性.展开更多
Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this pro...Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this problem was transformed into a strong stabilization problem associated with a related plant family G (s, δ). Results A necessary solvability condition was established in terms of the parity interlacing property of each element in G(s,δ). Another apparently necessary solvability condition is that every element in P(s,δ) must be stabilizable. Conclusion The two conditions will be compared with each other and it will be shown that every element in G(s,δ) possesses parity interlacing property if P(s,δ) is stabilizable.展开更多
An important consideration when using hot-dip galvanized tubular structures is the uncertainty of the joint behaviour due to the possible reduction in the global joint resistance produced by the vent holes required fo...An important consideration when using hot-dip galvanized tubular structures is the uncertainty of the joint behaviour due to the possible reduction in the global joint resistance produced by the vent holes required for the galvanizing process. This paper assesses the effect on the joint strength of the angle between the brace members and the chord in a K- or N-joints made with rectangular hollow sections. The study is focused on the case when those brace members include characteristic holes required for the hot-dip galvanizing process. To accomplish the objective of the proposed work, some tests on full-scale K- and N-joints, including angles of 35°, 45°, 55° and 90°, were carried out. The experimental work was complemented by a validated numerical simulation in order to give some design recommendations and to extend the research to other joint configurations.展开更多
Supplementary annotations on special forms 1to 4, discussion on the general characteristics of K(t) and K(t, t), and analyses on two noticeable limits are presented in this part. It is demonstrated that strong and wea...Supplementary annotations on special forms 1to 4, discussion on the general characteristics of K(t) and K(t, t), and analyses on two noticeable limits are presented in this part. It is demonstrated that strong and weak parabolic transforms can be employed to change the standard form of a multi-variable indeterminate form into xmK type, hence to derive the standard formulae of the limit and the differential.展开更多
Seismic gap method is one of the effective earthquake prediction methods using seismicity patterns. However, this method has some limitations and uncertainty when using it singly in predicting earthquakes. This paper ...Seismic gap method is one of the effective earthquake prediction methods using seismicity patterns. However, this method has some limitations and uncertainty when using it singly in predicting earthquakes. This paper puts forward the prediction method using the dynamic seismicity pattern with dynamic implications. This method considers the formation and evolution of the seismic gap on the basis of plate movement and structural characteristics. Through analysis of 26 cases of earthquakes of MS≥5.0 occurring in East China and South China, this paper obtains the relationship between the main shock with seismic gap and active fault's location, as well as the relationship between the seismic gap and location and strike of active faults. Meanwhile, this paper provides a dynamic explanation of the differences in the formation and evolution patterns of the seismic gap between the two regions, thus providing the physical basis for and reducing the uncertainty of predicting earthquakes using the seismic gap method.展开更多
文摘本文基于三维区域空气质量模式WRF-Chem,通过修改模式化学模块,量化输出过程量和诊断量,提供了一种定量分析挥发性有机化合物(VOCs)源强不确定性对O_(3)生成影响的方法.为无法定量计算VOCs源强导致的臭氧生成率[P(O_(3))]偏差,以及由此对O_(3)体积分数分布和污染控制相关联的VOCs敏感区和NOx敏感区分布的误判提供了方法参考.采用标准统计参数对WRF-Chem模式的气象场与污染场模拟性能进行了评估,相关指标均优于前人结果.以INTEX-B(intercontinental chemical transport experiment-phase B)人为源、FINNv1(fire inventory from NCAR version 1)生物质燃烧源和MEGAN(model of emissions of gases and aerosols from nature)生物源作为基准源,并以卫星观测数据作为约束,对排放源进行改进,评估了源改进前后臭氧生成率[P(O_(3))]、O_(3)体积分数和O_(3)控制敏感区指标(Ln/Q)的变化情况.仅人为VOCs(AVOCs)源增加68%后,P(O_(3))模拟峰值增升比例达13%~82%,以北京观测站点为例,P(O_(3))模拟月均峰值增加42%(22.5×10^(-9) h^(-1)).对P(O_(3))形成贡献比例最大的主要化学反应是HO2+NO(占比约68%),AVOCs源增加68%后,该反应贡献比例下降至65%.在改进源下,P(O_(3))普遍增加达到2×10^(-9)~4×10^(-9) h^(-1),O_(3)各季节增幅较大的区域均主要集中在京津冀、长三角和珠三角中心城市及周边区域,与我国大型城市区基本都是VOCs敏感区的结论一致.整体而言,VOCs源强改进后,NOx敏感区O_(3)体积分数增加幅度不大,不超过4×10^(-9),而部分VOCs敏感区增幅超过20×10^(-9).VOCs源强的不确定性会影响O_(3)形成过程中NOx和VOCs敏感区的判断,特别是VOCs源强明显低估会夸大VOCs敏感区的范围,从而降低O_(3)调控对策的有效性.
文摘Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this problem was transformed into a strong stabilization problem associated with a related plant family G (s, δ). Results A necessary solvability condition was established in terms of the parity interlacing property of each element in G(s,δ). Another apparently necessary solvability condition is that every element in P(s,δ) must be stabilizable. Conclusion The two conditions will be compared with each other and it will be shown that every element in G(s,δ) possesses parity interlacing property if P(s,δ) is stabilizable.
文摘An important consideration when using hot-dip galvanized tubular structures is the uncertainty of the joint behaviour due to the possible reduction in the global joint resistance produced by the vent holes required for the galvanizing process. This paper assesses the effect on the joint strength of the angle between the brace members and the chord in a K- or N-joints made with rectangular hollow sections. The study is focused on the case when those brace members include characteristic holes required for the hot-dip galvanizing process. To accomplish the objective of the proposed work, some tests on full-scale K- and N-joints, including angles of 35°, 45°, 55° and 90°, were carried out. The experimental work was complemented by a validated numerical simulation in order to give some design recommendations and to extend the research to other joint configurations.
文摘Supplementary annotations on special forms 1to 4, discussion on the general characteristics of K(t) and K(t, t), and analyses on two noticeable limits are presented in this part. It is demonstrated that strong and weak parabolic transforms can be employed to change the standard form of a multi-variable indeterminate form into xmK type, hence to derive the standard formulae of the limit and the differential.
基金supported by the National Science and Technology Program of China Earthquake Administration (No. 2006BAC01B02-01-05)Anhui Provincial Science and Technique Foundation (No. 08010302204)Joint Earthquake Science Fundation (A08077)
文摘Seismic gap method is one of the effective earthquake prediction methods using seismicity patterns. However, this method has some limitations and uncertainty when using it singly in predicting earthquakes. This paper puts forward the prediction method using the dynamic seismicity pattern with dynamic implications. This method considers the formation and evolution of the seismic gap on the basis of plate movement and structural characteristics. Through analysis of 26 cases of earthquakes of MS≥5.0 occurring in East China and South China, this paper obtains the relationship between the main shock with seismic gap and active fault's location, as well as the relationship between the seismic gap and location and strike of active faults. Meanwhile, this paper provides a dynamic explanation of the differences in the formation and evolution patterns of the seismic gap between the two regions, thus providing the physical basis for and reducing the uncertainty of predicting earthquakes using the seismic gap method.