【摘 要】
：
This work analyzes and discusses the influence of human activities on the meteorological conditions related to winter haze events in Beijing,Tianjin,and Hebei (i.e.,the Jing-Jin-Ji region) during 1961-2016,using the results of two numerical simulation exp
【机 构】
：
Notional Climate Center,China Meteorological Administration,Beijing 100081,China;Collaborative Innov
论文部分内容阅读
This work analyzes and discusses the influence of human activities on the meteorological conditions related to winter haze events in Beijing,Tianjin,and Hebei (i.e.,the Jing-Jin-Ji region) during 1961-2016,using the results of two numerical simulation experiments based on the Community Atmosphere Model version 5.1.1 (http:∥www.cesm.ucar.edu/models/cesm1.0/cam/docs/ug5_1_1/book1.html) used in the international Climate Variability and Predictability Programme (CLIVAR)Climate of the 20th Century Detection and Attribution Project (C20C+ D&A).The results show that,under the influence of human activities,the changes in dynamical and thermal meteorological conditions related to winter haze events in the Jing-Jin-Ji region are conducive to the formation and accumulation of haze,and prevent the diffusion of pollutants.The dynamical conditions mainly include the obvious weakening of the East Asian winter monsoon (EAWM) and the enhancement of the near-surface anoma-lous southerly wind.The thermal conditions include the obvious increase in surface temperature,and the enhancement of water vapor transport and near-surface inversion.The relative contribution of dynamical and thermal conditions to the variation of haze days in the Jing-Jin-Ji region is analyzed using statistical methods.The results show that the contribution of human activities to the increase of haze days in the Jing-Jin-Ji region is greater than that of natural forcing for the study period.To be specific,the dynamical meteorological factors contribute more to the haze days than the thermal meteorological factors.The contribution of thermal meteorological factors is basically the same in both scenarios.
其他文献
Semiconductor photocatalysis is a potential pathway to solve the problems of global energy shortage and environmental pollution.Black phosphorus (BP) has been widely used in the field of photocatalysis owing to its features of high hole mobility,adjustabl
The ambitious global targets on decarbonization present the need for massive integration of renewable generation in power systems,resulting in a significant decrease in the system inertia.In addition to the reduction in system inertia,the transmission sys
Microseismic (MS) event locations are vital aspect of MS monitoring technology used to delineate the damage zone inside the surrounding rock mass.However,complex geological conditions can impose significantly adverse effects on the final location results.
机械式自动垂直钻具具有耐高温、成本低和适用范围广等优点,其在深部资源勘探领域有广阔的应用前景,但纯机械式结构导致其纠斜精度易受外界环境的干扰.为进一步提高机械式自动垂直钻具的纠斜精度,对不同强度黏滑振动下钻具稳定平台的控制性能进行研究.首先,通过构建钻具稳定平台控制性能的数学分析模型,得到影响稳定平台控制性能的因素.然后,利用ADAMS(automatic dynamic analysis of mechanical systems,机械系统动力学自动分析)软件建立黏滑振动下钻具稳定平台的多刚体动力学仿真
踩踏式除草是有效的有机水田除草方式,对该除草过程进行仿真分析与评价可为除草机器人的设计提供重要参考.以踩踏式除草机器人为研究对象,基于ANSYS/LS-DYNA软件中的SPH(smoothed particle hydrodynamics,平滑粒子流体动力学)算法建立机器人踩踏式除草过程的有限元模型,分析了除草机器人与有机水田的土层、水层之间的多相耦合关系,并模拟了踩踏式除草的动态过程.基于踩踏式除草机理,分析了影响踩踏式除草效果的因素,并提出了除草效果的综合评价方法.基于仿真和试验,研究了机器人质量、运
以小腿三头肌的康复训练为应用背景,研究了滑块摇杆机构对小腿三头肌的康复作用.推导了滑块摇杆康复机构的矢量方程,建立了其数学模型,并利用MATLAB软件进行了滑块摇杆康复机构的运动仿真.结果显示:通过控制机构滑块的位移、速度和加速度可以间接地控制末端执行器的运动,从而形成能满足患者不同需求的康复模式;为保证滑块摇杆康复机构在使用过程中的安全性,滑块位移的变化区间应为200～700 mm.开展了滑块摇杆康复机构对小腿三头肌的按摩实验.结果显示,使用滑块摇杆康复机构后,小腿三头肌的表面肌电信号明显改变,使用前后
海堤堤前设计波高直接影响海堤的堤顶高程、结构及投资,对海堤设计意义重大.以大鹏湾海堤为例,通过确定海域风浪条件、设计潮位与计算组合,构建研究区域数值模型,分析大鹏湾波高变化规律,计算确定海堤堤前波高,为开展海堤达标加固设计工作提供参考.
Staphylococcus aureus (S.aureus) is a leading human pathogen capable of producing severe invasive infec-tions such as bacteremia,sepsis,and endocarditis with high morbidity and mortality,exacerbated by the increasingly widespread antibiotic resistance exe
Efficient fast-charging technology is necessary for the extension of the driving range of electric vehicles.However,lithium-ion cells generate immense heat at high-current charging rates.In order to address this problem,an efficient fast charging-cooling
国内雨夜标线光学性能逆反射亮度系数(潮湿环境和连续降雨环境)有相关的评定依据,但无相应的检测设备和检测方法;漫散射照明下的亮度系数缺乏相关检测方法和评定标准.本文对比分析国内外雨夜标线相关检测标准,对道路标线检测参数展开分析,认为我国可参考国外相关检测方法和标准进行雨夜标线检测.