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201.
利用线性拟合、Mann—Kendall方法、小波分析对石羊河流域五个测站空间平均的近50年来的逐日风速资料进行了倾向、周期、突变等特性分析。研究结果表明:1959年至2008年间,整个石羊河流域风速呈减小趋势,变化率约为-0.004m/(s.a).而上游风速呈现明显的上升趋势。四个季节中冬季风速降低速度最大,而夏季风速呈现上升趋势。风速的长期变化还具有一定的突变性,年平均风速在1988年出现了由高到低的突变,表明风速开始下降。复值Morlet小波分析的结果显示,风速变化存在6a、13a、19a、25a四个峰值。其中19a的时间尺度为第一主周期。 相似文献
202.
以《量和单位》(GB3100—3102-1993)为依据,列举了各种常见的错误使用量和单位的名称和符号、量和单位非标准化的例子,对其进行了分析和探讨,提出标准化对策。 相似文献
203.
204.
化石燃料的大量使用所排放的温室气体使得全球气候日益变暖,低碳经济的提出成为了目前全球应对气候变暖的主要策略,而发展中国家在进行低碳技术引进时常常面临来自发达国家的知识产权贸易壁垒。本文从"公地悲剧"角度解析气候变暖的经济学根源,从"反公地悲剧"角度揭示低碳技术转让过程中发达国家以知识产权为借口制造技术壁垒的经济学缘由。 相似文献
205.
Xiuying Zhao Xinming Wang Xiang Ding Quanfu He Zhou Zhang Tengyu Liu Xiaoxin Fu Bo Gao Yunpeng Wang Yanli Zhang Xuejiao Deng Dui Wu 《环境科学学报(英文版)》2014,26(1):110-121
Organic acids as important constituents of organic aerosols not only influence the aerosols' hygroscopic property, but also enhance the formation of new particles and secondary organic aerosols. This study reported organic acids including C14–C32fatty acids, C4–C9dicarboxylic acids and aromatic acids in PM2.5collected during winter 2009 at six typical urban, suburban and rural sites in the Pearl River Delta region. Averaged concentrations of C14–C32fatty acids, aromatic acids and C4– C9 dicarboxylic acids were 157, 72.5 and 50.7 ng/m3, respectively. They totally accounted for 1.7% of measured organic carbon. C20–C32fatty acids mainly deriving from higher plant wax showed the highest concentration at the upwind rural site with more vegetation around, while C14–C18fatty acids were more abundant at urban and suburban sites, and dicarboxylic acids and aromatic acids except 1,4-phthalic acid peaked at the downwind rural site. Succinic and azelaic acid were the most abundant among C4–C9dicarboxylic acids, and 1,2-phthalic and 1,4-phthalic acid were dominant aromatic acids. Dicarboxylic acids and aromatic acids exhibited significant mutual correlations except for 1,4-phthalic acid, which was probably primarily emitted from combustion of solid wastes containing polyethylene terephthalate plastics. Spatial patterns and correlations with typical source tracers suggested that C14–C32fatty acids were mainly primary while dicarboxylic and aromatic acids were largely secondary. Principal component analysis resolved six sources including biomass burning, natural higher plant wax, two mixed anthropogenic and two secondary sources; further multiple linear regression revealed their contributions to individual organic acids. It turned out that more than 70% of C14–C18fatty acids were attributed to anthropogenic sources, about 50%–85% of the C20–C32fatty acids were attributed to natural sources, 80%–95% of dicarboxylic acids and 1,2-phthalic acid were secondary in contrast with that 81% of 1,4-phthalic acid was primary. 相似文献
206.
Fast increasing of surface ozone concentrations in Pearl River Delta characterized by a regional air quality monitoring network during 2006-2011 总被引:1,自引:0,他引:1
Jinfeng Li Keding Lu Wei Lv Jun Li Liuju Zhong Yubo Ou Duohong Chen Xin Huang Yuanhang Zhang 《环境科学学报(英文版)》2014,26(1):23-36
Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone(O3), NO2and total oxidant(Ox) were analyzed by both linear regression and cluster analysis. A fast increase of regional O3concentrations of 0.86 ppbV/yr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0.61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories – rural stations(non-urban) and suburban/urban stations. The O3concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime(13%/yr referred to 2006 level) was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3production is mainly volatile organic compounds(VOC)-controlled. However, the photochemical O3production is sensitive to both NOx and VOC for O3pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control. 相似文献
207.
"十二五"以来,国家不断完善总量减排和污染源监测管理制度,出台了一系列新的文件和办法,强化了监测信息公开,严格了总量减排监测体系建设和运行管理考核。新形势下,对污染源监督性监测工作提出了新的工作要求,针对当前监督性监测工作中存在的一些问题,从标准核实、规范监测、信息公布、软件升级等方面提出了相应的措施和建议。 相似文献
208.
以南京市城南河为研究对象,分别提取上中下游的水体样本,分析水质中的氮、磷、COD等水质指标,并利用变性梯度凝胶电泳技术(DGGE)分析了城南河不同位置的细菌多样性。结果表明:城南河水体中的平均总氮为30.06 mg/L,总磷为6.14 mg/L,COD为42.03 mg/L,均超过国家V类水质标准。结合外观,城南河属于严重污染的典型黑臭河流。DGGE分析的结果表明:城南河具有较高的细菌多样性,优势菌群主要是变形菌门和拟杆菌门2大类群,且不同取样点细菌种类差别不大。 相似文献
209.
210.
浅析大沽河流域水质状况及变化趋势 总被引:1,自引:0,他引:1
大沽河流域监测数据显示:2012年,大沽河干流水质良好,功能区达标率为100%,多数断面综合污染指数呈丰水期枯水期平水期。大沽河主要支流水质总体为轻度污染,主要污染指标为五日生化需氧量、化学需氧量、氟化物,功能区达标率为68.8%,从污染较重河流(桃源河、云溪河、洙河下游)不同水期综合污染指数来看,桃源河和洙河下游呈丰水期﹥平水期﹥枯水期;云溪河由于贯穿胶州城区,受农业面源、降水因素影响较小,呈枯水期﹥丰水期﹥平水期。2006—2012年,大沽河干流水质基本保持稳定,主要支流水质呈改善趋势。 相似文献