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系留气球垂直观测平台的构建与应用 总被引:2,自引:0,他引:2
利用1 600 m~3车载系留气球,构建大气复合型污染垂直观测平台。利用该平台对近地大气边界层的多种气象要素、多种污染物浓度水平及其物理化学特性进行高分辨的垂直测量,用以研究大气边界层的形成和演变及大气污染物垂直分布和变化特征、大气光化学过程的垂直变化以及污染物的区域输送。该平台以0.5 m/s的速度进行升降,于2013年12月在上海成功应用于大气污染垂直观测,观测中共获取大气污染物有效廓线50余组。利用观测数据,初步探索上海近地层复合型大气污染的生消机制及大气污染物垂直分布特征,为上海市空气污染预警和防控对策机制的制定提供技术支撑。 相似文献
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The evolution of empty nuptial gifts in a dance fly, Empis snoddyi (Diptera: Empididae): bigger isn't always better 总被引:2,自引:0,他引:2
Jennifer A. Sadowski Allen J. Moore Edmund D. Brodie III 《Behavioral ecology and sociobiology》1999,45(3-4):161-166
Adaptive female choice is thought to have led to the evolution of nutritionally valuable nuptial gifts in many insect species.
However, in several dance fly species, males offer and females accept “empty gifts” with no nutritional value. In the species
studied here, Empis snoddyi Steyskal, males produce empty balloons comprised of hundreds of silk bubbles and form mating swarms that females approach
to investigate males. Males within the swarm engage in agonistic interactions. The empty balloon has been hypothesized to
be an indicator of male condition such that males with larger balloons are predicted to have higher mating success and be
more successful in male-male interactions than males with smaller balloons. We examined the role of male body size and balloon
size in the context of intersexual and intrasexual selection. We found that neither male body size nor balloon size affected
the outcome of pairwise male-male interactions. Using multiple-regression techniques, we found significant linear selection
for increasing male body size and decreasing balloon size associated with mating success, a surprising result given a positive
relationship between male body size and balloon size. A visualization of selection showed the highest peak of male mating
success for larger males with intermediate-size balloons. These results can be explained by a trade-off between long-range
attraction of females using large balloons and close-range attraction of females via improved flying efficiency associated
with smaller balloons. Both male body size and balloon size are important components in determining male mating success; however,
the empty balloon does not appear to play a typical role as a sexually selected ornament.
Received: 29 December 1997 / Accepted after revision: 7 October 1998 相似文献
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Aerostat-lofted instrument and sampling method for determination of emissions from open area sources
An aerostat-borne instrument and sampling method was developed to characterize air samples from area sources, such as emissions from open burning. The 10 kg battery-powered instrument system, termed “the Flyer”, is lofted with a helium-filled aerostat of 4 m nominal diameter and maneuvered by means of one or two tethers. The Flyer can be configured variously for continuous CO2 monitoring, batch sampling of semi-volatile organic compounds (SVOCs), volatile organic compounds (VOCs), black carbon, metals, and PM by size. The samplers are controlled by a trigger circuit to avoid unnecessary dilution from background sampling when not within the source plume. The aerostat/Flyer method was demonstrated by sampling emissions from open burning (OB) and open detonation (OD) of military ordnance. A carbon balance approach was used to derive emission factors that showed excellent agreement with published values. 相似文献
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