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发达国家污染土地置换开发管理实践及其对我国的启示 总被引:14,自引:0,他引:14
污染土地置换开发是一个复杂的过程,涉及技术、法律、经济和社会等诸多问题.选择管理技术相对比较成熟和先进的美国、欧盟国家、加拿大以及日本作为案例,深刻剖析国际上污染土地置换开发管理的经验与教训,提出有效的城市土地利用规划、公平合理的经济责任界定、合适的资金筹措机制、灵活选择土壤污染修复目标、污染土地风险评估等级划分、多利益方的共同参与等6点启示,以期对我国日益受到重视的污染土地置换开发管理工作提供借鉴. 相似文献
393.
Markus??stEmail author Ron?Ydenberg Kai?Lindstr?m Mikael?Kilpi 《Behavioral ecology and sociobiology》2003,54(5):451-457
Both theoretical and empirical work has shown that group size increases with increasing ecological constraints on solitary breeding. Ecological constraints refer to extrinsic factors such as availability of breeding sites, food or mates. Common eider (Somateria mollissima) females pool their broods and share brood-rearing duties, or rear broods alone. Females are often in poor condition at hatching, as incubation is accomplished without feeding, and variation in body condition is largely environmentally induced and thus unpredictable. We found that the intensity of and duration of parental care that females provide is positively correlated with their body condition at hatching. This suggests that body condition is an ecological constraint on successful solitary breeding. We further observed that group productivity in common eider broods is a decelerating function of the number of tending females. As predicted, females in poorer condition (i.e., facing stronger ecological constraints) were found in larger groups. This result is straightforward if solitary tenders can enter any group at no cost. However, if entry is group-controlled, stable groups of non-relatives are predicted not to occur when per capita reproduction declines with group size. The N-person staying incentive model permits groups to form under these conditions, because reproduction is unevenly divided between dominants and subordinates in the group. We discuss the plausibility of these alternative models of group size for understanding the grouping behavior of brood-caring female common eiders.Communicated by M. Webster 相似文献
394.
为探明蝶啶荧光分析法在尸食性蝇类成虫日龄推断中的应用潜力,采用荧光分光光度计对4种恒温和自然变温下巨尾阿丽蝇(Aldrichina grahami)雌雄成虫头壳蝶啶含量与日龄的关系进行了研究.结果表明,性别、温度和日龄对成虫蝶啶含量均有显著影响,其中日龄为最主要的影响因子.在16℃、20℃、24℃和28℃下,雌雄成虫头壳蝶啶含量与日龄均呈显著的线性关系(P<0.01,R2>0.90).蝶啶积累速率与温度也呈显著的线性关系.应用蝶啶荧光分析法对自然变温下巨尾阿丽蝇雌雄成虫日龄的估计表明,估计日龄与实际日龄呈显著的线性关系,其中雌成虫日龄估计误差平均为2.68d,雄成虫为±1.56d.以上研究结果表明,蝶啶荧光分析法在巨尾阿丽蝇成虫尤其是雄成虫日龄的推断中具有较大的应用价值.图4表2参19 相似文献
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396.
Food access, brood size and filial cannibalism in the fantail darter, Etheostoma flabellare 总被引:4,自引:0,他引:4
We compared the occurrence of filial cannibalism in fed and starved male fantail darters (Etheostoma flabellare). All males in the experiment consumed eggs, and 56% ate all of their eggs. A male's initial body condition did not explain
the number of eggs that he ate. Neither did non-fed males eat more eggs than fed males. Fed males were able to maintain better
body condition during the experiment, but the change in body condition also depended on the number of eggs eaten. Thus, males
who ate more eggs were able to maintain better body condition.The most important determinant of whether or not a male ate
all of his eggs was his initial egg number. Males with small egg masses ate all of their eggs whereas males with large egg
masses were only partial cannibals. There was, however, no difference in the total number of eggs eaten by total and partial
cannibals. We conclude that eggs are only partially eaten for energetic reasons. We also suggest that small egg masses are
completely consumed because the costs of caring for a small egg mass may exceed the expected reproductive benefits of a small
egg mass.
Received: 26 January 1996 / Accepted after revision: 2 November 1996 相似文献
397.
大孔径聚砜超滤膜的研究 总被引:5,自引:0,他引:5
作者用向铸膜液中加水的方法对制备大孔膜进行了研究。选择适宜的聚砜浓度和水含量,可以制得截留分子量为15万的聚砜超滤膜。该膜对丙种球蛋白的截留率>95%,纯水透水速度可达70-80ml/cm^2·h(0.1MPa)。 相似文献
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为了监测江汉湖群的湖泊资源,研究湖泊围垦变化对湖区环境生态的影响,本试验利用陆地卫星遥感图象的光学仿射纠正技术和机助扫描统计方法,对湖北省湖泊的个数和面积进行了统计,并将八十年代初与五十年代末统计数据作了比较分析。发现江汉湖群的湖泊个数由五十年代末的609个减少到现在的309个,湖泊常年水位面积由4708km~2缩减到2657km~2.七十年代以来的过度围垦,使湖区生态平衡遭到严重破坏,调蓄、水产和水资源受到损失、研究表明.监测江汉湖群的动态演变,进行合理的湖区开发,加强湖泊的科学管理,已到非重视不可的时候了. 相似文献