兰州市的生态功能区划

在生态环境调查的基础上,依据生态功能区划的基本原则,结合兰州市生态系统的空间特征分析、生态敏感性评价以及生态服务功能评价,建立了二元圈层结构的规划理念,制定了兰州市生态功能区划。把兰州市划分为4个1级功能区和3个2级功能区,并明确阐述了各功能区的主要特点、主要问题和主导功能,力图为兰州市建立良好的生态功能结构提供科学依据。     

遗传算法推求瞬时单位线参数并计算流量过程线

城市雨水地表径流模型的目的是推求城市雨水地表径流的流量过程线，从而模拟雨水的地表径流过程。瞬时单位线法是解决模型的一种方法。由瞬时单位线推求S曲线和时段单位线，可以得到城市雨水口径流的流量过程线。瞬时单位线是该过程的基础，求解瞬时单位线参数N和K值是十分重要的。与过去用矩法求解这两个参数比较，介绍了用遗传算法来推求瞬时单位线参数的方法和过程，并验证了遗传算法推求参数的可行性和可信性。     

Airborne bacteria associated with particulate matter from a highly urbanised metropolis: A potential risk to the population’s health

• The airborne bacteria of Mexico City are representative of urban environments. • Particle material<10 µm influenced the type and quantity of airborne bacteria. • The diversity and richness of bacteria were higher in the rainy season. • The emission & transport of airborne bacteria determine the atmosphere’s microbiome. • Bacterias as Kocuria, Paracoccus, and Staphylococcus were in the air of Mexico City. Bacteria in the air present patterns in space and time produced by different sources and environmental factors. Few studies have focused on the link between airborne pathogenic bacteria in densely populated cities, and the risk to the population’s health. Bacteria associated with particulate matter (PM) were monitored from the air of Mexico City (Mexico). We employed a metagenomic approach to characterise bacteria using the 16S rRNA gene. Airborne bacteria sampling was carried out in the north, centre, and south of Mexico City, with different urbanisation rates, during 2017. Bacteria added to the particles were sampled using high-volume PM₁₀ samplers. To ascertain significant differences in bacterial diversity between zones and seasons, the Kruskal-Wallis, Wilcoxon tests were done on alpha diversity parameters. Sixty-three air samples were collected, and DNA was sequenced using next-generation sequencing. The results indicated that the bacterial phyla in the north and south of the city were Firmicutes, Cyanobacteria, Proteobacteria, and Actinobacteria, while in the central zone there were more Actinobacteria. There were no differences in the alpha diversity indices between the sampled areas. According to the OTUs, the richness of bacteria was higher in the central zone. Alpha diversity was higher in the rainy season than in the dry season; the Shannon index and the OTUs observed were higher in the central zone in the dry season. Pathogenic bacteria such as Kocuria, Paracoccus, and Micrococcus predominated in both seasonal times, while Staphylococcus, Corynebacterium, and Nocardioides were found during the rainy season, with a presence in the central zone.     

汶川地震局部地形对地震动的影响

关于局部地形对地震动的影响,一直是地震工程学的研究热点。选取汶川地震中自贡地形台有强震记录的山脊地形和典型地震灾害的北川县城河谷地形进行了强震观测记录、规范方法和数值模拟下的地形放大效应分析,结果表明:(1)规范法基本上可满足一般工程场地的要求;(2)对人员密集居住的高度大于60 m的较陡地形,建议应进行二维(三维)数值模拟下的地形效应分析。这为规范的修订提供了一些基础资料。     

我国城市噪声污染现状与特征

通过对8个大城市功能区噪声监测数据的分析,阐述了我国城市噪声主要污染区域、主要超标时段、噪声时间分布及季度变化等特征,为管理部门制定噪声防治政策提供参考.     

日喀则市农业生态足迹研究

采用水资源足迹和化石能源供给地概念,对日喀则市2005年农业活动的生态足迹进行实证分析.结果表明:日喀则市农业综合足迹为334 153.27 hm2,占日喀则市总足迹的77.6%,其中,化石能源地足迹仅占农业综合足迹的13.3%,表明农业现代化程度不高.对农业综合足迹贡献最大的是耕地和牧草地,二者合占65.6%,主要原因是大量使用农用化学品和牧草地严重超载;生产足迹占农业综合足迹的82.8%,说明农村占用的大部分资源主要用来进行资源再生产.对日喀则市农业综合足迹的实证研究表明,资源产量法可以有效减小土地面积法引起的生态赤字扩大化现象,将肉、蛋、奶产品作为次级产品更能反映牧草地利用现状.      

沪苏边缘区经济合作的时空关系及其对策 --以南通和苏州为例

沪苏边缘区是沪苏经济联系较为密切的区域.以江苏省的南通和苏州两市为研究对象,首先对沪苏边缘区经济合作进展的时空关系进行了总结,时间上表现为三个阶段的历史演进,空间上表现为合作的地区性差异.接着,分析了沪苏边缘区经济合作地区性差异的主要原因,包括经济距离、思想观念和投资环境的差异.在此基础上,对沪苏边缘区的合作绩效进行了评价,认为沪苏边缘区合作绩效明显,合作的方向是经济一体化.基于对北美自由贸易区、欧盟和APEC三个典型的区域合作组织模式的成功经验的对比分析,最后提出了进一步推进沪苏边缘区合作的对策.     

西安市南郊春季降水化学成分特征

2010年3-4月间采集了7次西安南郊降水样品,测定电导率、pH值、主要离子浓度.结果表明,降水pH值的平均值为6.6;电导率平均为110.5 μs/cm,说明降水中水溶性离子浓度高.Ca2+为含茸最丰富的阳离子,平均浓度为15.3 mg/L.由于北方春季沙尘天气频繁,空气中固体颗粒较多,所以降水中Ca2+浓度较高.同...     

“十一五”期间安庆市环境空气质量状况分析

根据安庆市环境空气质量监测数据,对＂十一五＂期间安庆市环境空气质量状况进行了分析,并与＂十五＂期间进行了比较。结果表明,＂十一五＂期间安庆市环境空气质量优良率总体呈下降态势,首要污染物主要为PM10,老城区的污染重于开发区。采暖期SO2及PM10的质量浓度高于其它月份,NO2测值随季节变化不明显,2009年起各种污染物浓度有所下降。与＂十五＂比较,＂十一五＂期间PM10的质量浓度大幅下降,SO2及NO2均有不同幅度的上升,环境空气质量优良率比＂十五＂略有下降。     

新乡市室外尘土中多环芳烃的分布特征

测定了新乡市不同功能区的20个室外尘土样品中16个中美国环保局优先控制的多环芳烃(PAHs).结果显示室外尘土中PAHs总和(EPAHs)为124～1 669μg/kg(干重).虽然广场类型的室外尘土样品中ΣPAHs含量均值小于生活区和工业区类型的,但3组样品的数值之间并无明显差异.同分异构体比率显示样品中PAHs以燃...