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991.
以2007年4月~2008年12月贵州龙里实验区的降水监测数据为基础,运用统计学方法对该地区大气降水酸度和化学组成的特征及其季节变化趋势进行分析.结果表明,研究期内当地的降水pH均值为4.70,酸雨占降雨次数的70.1%和总降雨量的76.7%.酸雨的发生呈现一定的季节变化特征,其中春季为酸雨高发季节.降水中SO42-、NO3-、NH4+、Ca2+等含量较高.与相关研究进行对比,初步认为该地区大气降水所带来的S和N的湿沉降量尚未超过当地生态系统的酸沉降临界负荷. 相似文献
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993.
Carotenoid pigments cannot be synthesized by vertebrates but must be ingested through the diet. As they seem to be a limited
resource, carotenoid-based ornaments are particularly interesting as possible honest signals of individual quality, in particular
of foraging efficiency and nutritional status. Some studies have demonstrated the condition dependence of carotenoid-based
plumage in birds. However, many other carotenoid-pigmented bare parts (i.e. skin, caruncles, bills, cere, and tarsi) are present
in birds but, in comparison with plumage, little is known about these traits as indicators of individual quality. Here, we
show that the eye ring pigmentation and bill redness of the red-legged partridge (Alectoris rufa) are positively associated to body condition and recent changes in body mass. Also, we found a negative relationship between
these two traits and heterophil-to-lymphocyte ratio, an indicator of physiological stress (the relationship with bill redness
being significant only for males). In an experiment, we found that after a period of reduction in food intake (with the consequent
loss of body mass), food-restricted birds showed lower eye ring pigmentation than ad-libitum-fed birds. Therefore, different
ornaments seem to reflect changes in body condition but at different speeds or intensities (eye ring, a fleshy ornament, appears
to respond more rapidly to changes in the nutritional status than a keratinized structure as the bill). These results indicate
that carotenoid-based ornaments are condition-dependent traits in the red-legged partridge, being therefore susceptible to
be employed as honest signals of quality in sexual selection. 相似文献
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995.
BI Xiao-yi WANG Peng JIANG Hong XU Huan-yan SHI Shu-jie HUANG Jun-li 《环境科学学报(英文版)》2007,19(12):1510-1515
The catalyst of CuOx/Al2O3 was prepared by the dipping-sedimentation method using γ-Al2O3 as a carrier. CuO and Cu2O were loaded on the surface of γ-Al2O3, characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In the presence of CuOx/Al2O3, the microwave-induced chlorine dioxide (ClO2) catalytic oxidation process was conducted for the treatment of synthetic wastewater containing 100 mg/L phenol. The relationships between removal percentage and initial ClO2 concentration, catalyst dosage, microwave power, contact time, initial phenol concentration and pH were investigated and the results showed that microwave-induced ClO2-CuOx/Al2O3 process could effectively degrade contaminants in a short reaction time with a low oxidant dosage, extensive pH range. Under a given condition (ClO2 concentration 80 mg/L, microwave power 50 W, contact time 5 min, catalyst dosage 50 g/L, pH 9), phenol removal percentage approached 92.24%, corresponding to 79.13% of CODCr removal. The removal of phenol by microwave-induced ClO2-CuOx/Al2O3 catalytic oxidation process was a complicated non-homogeneous solid/water reaction, which fitted pseudo-first-order by kinetics. Compared with traditional ClO2 oxidation, ClO2 catalytic oxidation and microwave-induced ClO2 oxidation, microwave-induced ClO2 catalytic oxidation system could significantly enhance the degradation efficiency. It provides an effective technology for the removal of phenol wastewater. 相似文献
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开展了对云南省跨国界水体水环境及相关信息的全面调查,针对存在的环境问题进行了分析,并对环境安全提出了对策。 相似文献
1000.
"十二·五"初对伊宁市"十一·五"末期生态环境质量进行综合评价,对今后的生态环境保护以及治理都具有很强的参考和指导意义。本文在生态环境质量评价结果统计分析的基础上,找出当前的主要生态环境问题及变化情况,并对此制定出相应生态环境保护具体对策。 相似文献