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91.
用激光解吸附电离飞行时间质谱法检测悬浮土壤颗粒物 总被引:1,自引:0,他引:1
在自行研制的气溶胶飞行时间激光质谱仪(ATOFLMS)上实时探测单个悬浮土壤颗粒的粒径和化学成分。利用双束连续激光对单个粒子的空气动力学粒径进行测量,并用266 nm的Nd∶YAG激光器对气溶胶单粒子进行解吸附电离作用,产物离子通过飞行时间质谱仪的无场漂移区后完成单粒子化学成分的检测。本实验中使用了4个不同地区的土壤样本,在实验室内对分析的样本进行预处理和再悬浮,通过导管引入ATOFLMS进行测量,得到大量单粒子的粒径和质谱数据。发现在众多的单粒子的阳离子质谱中,金属成分以地壳元素(Fe, K, Al, Ca)为主,在其他阳离子质谱中包含了Mg和Na等。对悬浮土壤粒子的粒径进行实时检测的结果表明这些粒子多以粗粒子为主, 粒径主要集中在1~2 μm。实验结果表明该仪器在大气气溶胶环境监测及相关研究领域具有重要的实用价值。 相似文献
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激光雷达研制及其探测大气气溶胶的实验研究 总被引:7,自引:2,他引:5
作为一种激光探测大气气溶胶特征的新技术,采用分子滤波技术的高光变分辨率激光雷达在国际上得到了发展,给出了对这种YAG激光雷达系统的理论分析并建立了实验装置,其接收望远镜孔径为300mm,YAG激光脉冲能量为150mJ。通过数值模拟与初步测量估计了激光雷达性能,测量了大气回向散射信号,测量结果表明实结果与理论分析一致。 相似文献
94.
In the atmospheric correction of satellite data in the visible and near-infrared bands, it is necessary to remove the adjacency effect due to the reflection from contiguous pixels. Evaluation of the influence of aerosol vertical distributions on the adjacency effect is done by calculating the single-scattering light intensity which, after the reflection at the ground surface, reaches the satellite sensor via a single scattering with a molecule or an aerosol particle. In the simulation, we assume aerosol vertical profiles similar to those used in the MODTRAN radiation transfer code, and those having a mixed layer with a uniform value of the aerosol extinction coefficient. We assume for the ground surface a simple model representing a border of land/sea surfaces. In spite of the single scattering approximation, it is confirmed that even if the optical thickness is the same, we have a larger adjacency effect when the extinction coefficient is large at higher altitudes. We also discuss the dependence of the adjacency effect on the aerosol optical thickness and that on the difference in the reflectances of the land and sea surfaces along the border. 相似文献
95.
The aim of this paper is to present a theoretical study of the aerosol penetration
through an electret fibrous filter, using a numerical approach. The aerosol sizes
considered in this study were in the submicron range, and in the numerical model,
the conventional mechanical mechanisms (impaction, interception, diffusion and
gravitationally settling) were taken into consideration along with the electrostatic
mechanisms, including the Coulombic and dielectrophoretic effects. The aerosol
penetration through an electret fibrous filter is heavily dependent on the aerosol
penetration of a single fibre. The aerosol penetration through a single electret
fibre under various filtration conditions was calculated. The effects of aerosol
diameter, aerosol and fibre charge state, face velocity, packing density and aerosol
dielectric constant on the aerosol penetration were investigated. 相似文献
96.
Effects of South China Sea/western North Pacific summer monsoon on tropospheric biennial oscillation (TBO) 总被引:2,自引:0,他引:2 下载免费PDF全文
Several theories have been developed to explain tropical biennial
oscillation (TBO), as an air--sea interactive system to impact Asian
and global weather and climate,
and some models have been established to produce a TBO. A
simple 5-box model, with almost all the key processes associated with
TBO, can produce a TBO by including air--sea interactions in the
monsoon regions. Despite that, the South China Sea/western North
Pacific summer monsoon (SCS/WNPSM), a very important monsoon
subsystem, is neglected. In this paper, based on the dynamical
framework of 5-box model, the term of SCS/WNPSM has been added and a
6-box model has been developed. Comparing the difference of TBO
sensibilities with several key parameters, air--sea coupling
coefficient α, SST-thermocline feedback coefficient
γ and wind-evaporation feedback coefficient λ,
between the modified model and original model, TBO is more sensible
to the parameters in the new model. The results imply that the
eastern Pacific and local wind-evaporation play more important roles
in the TBO when including SCS/WNPSM. 相似文献
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用气相色谱法定量测定了家用气雾杀虫剂中的丙烯菊酯、氯菊酯和增效醚。色谱柱为5%QF-1/Chro-mosorbWHP,以邻苯二甲酸二苯酯为内标物,测得的回收率分别为100%,102%,99.9%;变异系数为0.13,0.56,0.48,方法简便、快速、准确。 相似文献