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961.
Zhaoyu Zhu Houyun Zhou Tingping Ouyang Qinglu Deng Yaoqiu Kuang Ningsheng Huang 《国际发展与全球生态学杂志》2013,20(3):233-237
SUMMARY Water crises have occurred in more than 400 cities in China at the beginning of 2000. Investigation and statistical data suggest that there are five main problems in the management and utilization of water resources in China. These are (1) insufficient capacity and inhomogeneous space-time distribution of natural resources, (2) outdated construction of water conservancy projects and supply engineering, (3) unreasonable industrial water consumption, (4) increased water pollution and (5) incomplete management of the river basin and waterworks in city. It is necessary to take steps corresponding to the above-mentioned reasons to mitigate and even dispel the pressure on water resources for sustainable development of China as quickly as possible. 相似文献
962.
为有效控制防污漆中杀生物活性物质给海洋环境带来的不利影响,亟需开展活性物质的环境风险评估研究,为筛选环境友好型活性物质提供依据。以25种国产防污漆中的铜为评估对象,采用防污漆活性物质环境风险评估的针对性方法,分步进行暴露评估、危害性评估和风险表征。暴露评估采用海洋防污剂预测环境浓度模型(MAMPEC)中的港口、码头和开阔海域等典型暴露场景;危害性评估基于铜对淡水和海水水生生物的慢性毒性数据,采用物种敏感度分布法和评估因子法;风险表征采用熵值法。结果表明,铜对全部水生生物和海水生物的预测无效应浓度分别为2.8和2.3μg·L~(-1),藻类对铜最为敏感。除1种配方外,其余24种防污漆配方中铜的风险熵均小于1,可判定铜为"相对低风险"类活性物质,使用上述防污漆时铜对生态环境造成的风险较小。铜在不同暴露场景中的环境风险分析表明其对水流交换较弱海域的码头造成的风险最大,其次是默认港口和码头,对于公海造成的风险最小。根据现有的评估结果,设计含铜型防污漆配方时,应使铜的释放速率不大于33.5μg·cm~(-2)·d~(-1),以避免对较封闭海域的生态环境造成不可忽视的风险。 相似文献
963.
ABSTRACTLand use in China has changed remarkably over the past centuries with manifold implications for sustainable development. Investigation and projection of the land-use and land-cover changes (LUCC) have therefore become critical to promote the understanding of the LUCC process and the interactions with human societies. Scientists had devoted great efforts to create, process, and interpret comprehensive historical land-use/cover datasets, and to simulate future land-use systems under different scenarios. We synthesize the literature on the historical trajectories of LUCC in China, and summarize existing efforts of scenario developments for the projection of spatially explicit LUCC. Our review therefore provides salient suggestions for future land-use change analysis. 相似文献
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966.
Using sequence variation in the mitochondrial cytochrome oxidase I locus, we estimated the population structure and phylogeography
of the intertidal acorn barnacle, Chthamalus anisopoma, and its gastropod predator, Mexacanthina lugubris angelica. Both are endemic to the Gulf of California, being derived from taxa on the Pacific coast of the Baja peninsula, and both
exhibit phenotypic plasticity for traits affecting their coevolutionary interactions. Consistent with expectations based on
differences in dispersal, C. anisopoma populations generally lack geographic structure, while those of M. l. angelica are more strongly structured. However, the variable degree of differentiation in both species suggests that the extent of
reciprocal selection and local adaptation in the species will vary geographically, a result consistent with the concept of
a geographic mosaic of coevolution. The pattern of variation in C. anisopoma shows clear evidence of recent spatial expansion, possibly due to increased habitat availability following the last glacial
maximum. Phylogeographic analyses suggest that M. l. angelica diversified into three distinct clades after the colonization of the Gulf. Overall, our results illustrate how dispersal
potential, geological and climatic events, and recent population growth have impacted the pattern of sequence variation in
the two species. 相似文献
967.
采用Fenton试剂氧化—曝气生物滤池组合工艺对某制药厂常规生化处理后的废水进行深度处理.实验结果表明,Fenton试剂氧化的适宜操作条件为pH=5,ρ(H2O2)∶COD=1.5、n(H2O2)∶n(Fe2+)=2,反应时间为60min.经氧化处理后的废水再进入曝气生物滤池进行生化处理,最终出水COD小于80 mg/L,色度小于10倍,处理效果良好. 相似文献
968.
969.
970.
As the backland of the Qinghai-Tibet Plateau, the river source region is highly sensitive to changes in global climate. Air temperature estimation using remote sensing satellite provides a new way of conducting studies in the field of climate change study. A geographically weighted regression model was applied to estimate synchronic air temperature from 2001 to 2015 using Moderate-Resolution Imaging Spectroradiometry (MODIS) data. The results were R2?=?0.913 and RMSE?=?2.47 °C, which confirmed the feasibility of the estimation. The spatial distribution and variation characteristics of the average annual and seasonal air temperature were analyzed. The findings are as follows: (1) the distribution of average annual air temperature has significant terrain characteristics. The reduction in average annual air temperature along the elevation of the region is 0.19 °C/km, whereas the reduction in the average annual air temperature along the latitude is 0.04 °C/degree. (2) The average annual air temperature increase in the region is 0.37 °C/decade. The average air temperature increase could be arranged in the following decreasing order: Yangtze River Basin > Mekong River Basin > Nujiang River Basin > Yarlung Zangbo River Basin > Yellow River Basin. The fastest, namely, Yangtze River Basin, is 0.47 °C/decade. (3) The average air temperature rise in spring, summer, and winter generally increases with higher altitude. The average annual air temperature in different types of lands following a decreasing order is as follows: wetland > construction land > bare land glacier > shrub grassland > arable land > forest land > water body and that of the fastest one, wetland, is 0.13 °C/year. 相似文献