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101.
Gary Shigenaka James E. Price 《Journal of the American Water Resources Association》1988,24(5):989-998
ABSTRACT: Results from the National Status and Trends Program, a nationwide effort to evaluate U.S. coastal and estuarine environmental quality, are analyzed to provide information about regional sources of organic contaminants in the benthic environment. Spearman's rank correlation procedure is applied to measurements of coprostanol, a chemical tracer of sewage, and three classes of organic compounds in sediments. The results suggest that discharges from publicly owned treatment works are responsible for concentrations of the organic compounds encountered in the northeastern coastal region, while other sources may predominate in the other regions of the country. 相似文献
102.
a production in the central, south central, and the south segments of the lagoon. In a system as large and complex as the lagoon,
N and P limitations are potentially subject to significant spatial and temporal variability. Total Kjeldahl nitrogen (TN)
was higher in the north (1.25 mg/liter) and lower in the south (0.89 mg/liter). The reverse pattern was observed for total
P (TP), i.e., lowest in the north (0.03 mg/liter) and highest at the south (0.14 mg/liter) ends of the IRL. This increased
P concentration in the SIRL appears to have a significantly large effect on chlorophyll a production compared with the other segments, as indicated by stepwise regression statistics. This relationship can be expressed
as follows: South IRL [chlorophyll a] =−8.52 + 162.41 [orthophosphate] + 7.86 [total nitrogen] + 0.38 [turbidity]; R
2= 0.98**. 相似文献
103.
104.
Status signals are traits that advertise an individual’s competitive abilities to conspecifics during aggressive disputes.
Most studies of status signals in birds have focussed on melanin-based plumage signals, but recent research shows that carotenoid-based
signals may also play a role in aggressive signaling. We assessed the relative importance of melanin- and carotenoid-based
plumage patches as agonistic signals in a small passerine, the golden whistler (Pachycephala pectoralis). Display signals in male golden whistlers include an unpigmented white throat patch, a carotenoid-based yellow breast and
nape band, and a melanin-based black chin-stripe. We found that only the white throat patch was correlated with contest-related
attributes. Males possessing large throat patches defended larger territories and commenced breeding earlier. When caged males
with either experimentally reduced, or unmanipulated throat patches were presented to conspecifics, those with experimentally
reduced patches attracted less aggression from male subjects. Focal males also responded faster to caged males with throat
patches similar in size to their own, suggesting that they may assess relative throat patch size before engaging in aggressive
encounters. Females did not discriminate between “reduced” or “control” treatments. Our data strongly suggest that only the
unpigmented throat patch functions as a status signal. As this signal is unlikely to have significant development costs, honesty
may be maintained through social costs. 相似文献
105.
根据“七五”期间全国14个城市湖泊富营养化调查拟定和筛选出的总氮、总磷、生化耗氧量、透明度和叶绿素a的含量五个评价参数,用评分法对我区三个主要湖(库)富营养化现状进行评价.柴窝堡湖和红岩水库已达富营养水平,乌拉泊水库达中营养水平. 相似文献
106.
我国环境标准的现状及完善对策 总被引:4,自引:0,他引:4
对我国环境标准的现状和存在的问题作了较为系统的分析,提出了七点完善我国环境标准制度对策的建议。 相似文献
107.
沈阳市环保产业发展现状及对策建议 总被引:1,自引:0,他引:1
结合2004年沈阳市环保产业调查工作,论述了沈阳市环保产业的发展现状,对制约产业发展的问题进行了分析,并提出了沈阳市环保产业健康发展的对策及建议。 相似文献
108.
本文对小窑湾海域的水化学,沉积物和生物体化学要素含量水平和分布进行了研究。其结果为,14种水化要素,没有一种要素超标;12种沉积化学要素超出环境允许标准;生物体中残毒量未超过生物允许标准此湾底质受污染晃北岸西部地段,并受控于水动力因素,最衙得出该湾环境变化几点认识。 相似文献
109.
110.
沈阳市环境空气颗粒物分布特征及重金属污染状况分析 总被引:4,自引:0,他引:4
研究了沈阳市环境空气中不同颗粒物的污染程度、分布特征及颗粒物组成,研究结果表明沈阳市TSP、PM10和PM2.5整体污染水平较高,PM10以下颗粒比例较高;重金属主要吸附在细小颗粒物上。 相似文献