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Molly K. Chambers Daniel M. White Michael R. Lilly Larry D. Hinzman Kristie M. Hilton Robert C. Busey 《Journal of the American Water Resources Association》2008,44(2):316-327
Abstract: Lakes are important water resources on the North Slope of Alaska. Freshwater is required for oilfield production as well as exploration, which occurs largely on ice roads and pads. Since most North Slope lakes are shallow, the quantity and quality of the water under ice at the end of winter are important environmental management issues. Currently, water‐use permits are a function of the presence of overwintering fish populations, and their sensitivity to low oxygen concentrations. Sampling of five North Slope lakes during the winter of 2004‐2005 shed some light on the winter chemistry of four lakes that were used as water supplies and one undisturbed lake. Field analysis was conducted for oxygen, conductivity, pH, and temperature throughout the lake depth, as well as ice thickness and water depth. Water samples were retrieved from the lakes and analyzed for Na, Ca, K, Mg, Fe, dissolved‐organic carbon, and alkalinity in the laboratory. Lake properties, rather than pumping, were the best predictors of oxygen depletion, with the highest dissolved‐oxygen levels maintained in the lake with the lowest concentration of constituents. Volume weighted mean dissolved‐oxygen concentrations ranged from 4 to 94% of saturation in March. Dissolved oxygen and specific conductance data suggested that the lakes began to refresh in May. 相似文献
3.
火灾高温下CFRP加固钢筋混凝土梁温度场分析 总被引:1,自引:0,他引:1
综合国外CFRP加固混凝土结构抗火试验相关研究,总结了CFRP的高温热工性能参数。用ANSYS软件对火灾高温下不同情况(无防火保护层和有防火保护层)和不同工况(防火涂料涂抹形式)下CFRP加固后的钢筋混凝土梁进行了温度场数值模拟研究。结果表明,防火涂料厚40 mm时,梁耐火极限可达2.5小时以上,且底面和两侧面全面涂抹防火涂料的防火效果最好。本文研究有助于进一步深入认识CFRP加固钢筋混凝土结构在高温下的力学性能和耐火极限,且对CFRP加固后的结构防火设计具有一定的指导意义。 相似文献
4.
Joachim Ruther 《Chemoecology》2004,14(3-4):187-192
Summary. Field tests were performed to evaluate the
response of the garden chafer, Phyllopertha horticola
(Coleoptera: Scarabaeidae) to known scarab attractants and to
investigate the influence of trap colour and height on the
number of captured beetles. Both sexes were attracted by a
lure mixture composed of geraniol, eugenol, and 2-phenylethyl
propionate (PEP) (ratio 3:7:3). When testing floral volatiles
individually, only geraniol, eugenol and methyl anthranilate
but not PEP was attractive. Response of garden chafer to (Z)-
3-hexen-1-ol was strongly male-biassed. Both the response
to floral volatiles and (Z)-3-hexen-1-ol was increased by
using funnel traps with yellow instead of grey vanes. Traps
positioned at 50 and 125 cm above ground captured significantly
more garden chafers than those at 200 cm. The
strongly male-biassed response to (Z)-3-hexen-1-ol suggests
that in P. horticola (subfamily Rutelinae) orientation towards plant volatiles emitted upon mechanical damage of plants is
part of the male mate finding strategy as recently demonstrated
for cockchafers of the genus Melolontha (subfamily Melolonthinae). Possible application of plant volatiles for
control of P. horticola is discussed. 相似文献
5.
水雾荷电净化空气飘尘与细菌的研究 总被引:1,自引:0,他引:1
研究一种高压静电水雾场产生的荷电净化空气中飘尘与细菌的方法。实验结果表明:在静电电压15kV、通风量540m~3/h的工况下,实验装置的一次性除尘效率高于80%、除菌效率达到88%以上;实验装置可以连续运行,能耗低、出风无二次污染。 相似文献
6.
N. O. Kin 《Russian Journal of Ecology》2008,39(4):254-260
Heavy metal accumulation by plant communities has been studied in different zones of impact of gas field development. The contents of heavy metals in different blocks of plant communities has proved to depend not only on the location of phytocenosis but also on its species composition. Communities dominated by species of the family Poaceae contain smaller amounts of heavy metals than those dominated by species of the family Asteraceae, especially of the genus Artemisia. The order of precedence in the accumulation of heavy metals in different blocks of plant communities has been revealed. 相似文献
7.
8.
Toscas PJ 《Environmental monitoring and assessment》2008,137(1-3):379-385
Ammonia is an important water quality variable, which in excess, can be detrimental to waterways and their ecosystems. In
the Ecosystem Health Monitoring Program in South-east Queensland ammonia is monitored monthly, however, often more than 50%
of the ammonia observations in Moreton Bay are below detection limit, making it difficult to draw useful inferences. In this
paper a clipped Gaussian random field is used to spatially model and map the probability of detectable concentration of ammonia.
The methodology is applied to the Moreton Bay samples collected in February 2005. The results suggest that for this month
the oceanic impacted areas have higher probability of detectable ammonia concentration than the areas closer to the main sources
of anthropogenic inputs. 相似文献
9.
重量法测定含动、植物油和矿物油废水应注意的问题 总被引:4,自引:0,他引:4
废水监测中,用重量法测定污(废)水中的动、植物油和矿物油是常用方法之一。为了保证测试结果的准确性,减少误差,提高分析测试质量,作者以多年的实践经验结合塔里木油田采油厂生产污水和餐饮行业生活废水的测定,对测定两种不同含油类废水应注意的问题进行探讨。供同行在实际工作中参考。 相似文献
10.
Lei Jun & Zhang Xiaolei Xinjiang Institute of Ecology Geography Chinese Academy of Sciences Urumqi China Institute of Geography Science Natural Resources Research Chinese Academy of Sciences Beijing .China 《中国人口.资源与环境(英文版)》2005,3(3)
As a special basic economic region in China, Xinjiang is situated in the arid area in the Northwest China. Oasis agriculture is the basis of the national economy. The development of oasis agriculture helps to accelerate the development of economy, social and environment. After 50 years of practice, from 1949 to 2002, oasis agriculture in Xinjiang enhanced rapidly the scale of agricultural industry and had great changes in its structure. The amount of cultivated area rose from 120.97*102 ha t… 相似文献