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291.
Guyuan Luo Faping Bu Xiaoyi Xu Jia Cao Weiqun Shu 《Environmental monitoring and assessment》2011,173(1-4):55-64
Field surveys were carried out from January 2007 to December 2008 to investigate seasonal variations of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) transported to the Linjiang Bay of the Three Gorges Reservoir, China. The results revealed that both DIN and DIP exhibited large seasonal variability. DIN (dominated by NH4?CN) concentrations were drastically higher in the dry season than those in the rainy season, and the same seasonal patterns of DIP concentrations and DIN and DIP fluxes were observed but inverse to that of DIN concentrations. The interannual variation in DIN fluxes descended by 28.2% from 2007 to 2008, while DIP fluxes increased by 40.9%, which were closely constant with interannual changes in DIN and DIP concentrations, respectively. The study indicated that nutrient fluxes (DIN and DIP) were strongly correlated with both nutrient concentrations and river discharge, and the Linjiang Bay received approximately 3,416 × 103 kg DIN and 324 × 103 kg DIP every year. In addition, DIN mainly originated from point sources, but DIP originated from non-point sources. It is shown that to control point source pollution is the most effective step for water quality improvement and reducing nutrient loading inputs in the Linjiang Bay. 相似文献
292.
战略环境评价(SEA)和可持续发展 总被引:4,自引:0,他引:4
SEA的作用不仅仅在于将EIA(环境影响评价)扩展到更具战略意义的决策层,它还是迈向可持续发展的关键一步,它有助于从政策到计划、规划吧至最后的项目遵循可持续发展目标,SEA是联系目前正在进行的项目EIA和使人类活动达到维持环境质量这一目标的纽带,文章讨论了SEA开展的必要性,介绍了SEA的2种类型,结合英国开展的实例,论述了“遵循型”SEA的主要内容及其应用前景。 相似文献
293.
旅游者满意度是旅游地健康发展的重要指标,旅游者与旅游地的关系对旅游者满意度的影响是不容忽视的。通过引入自我效能感和社会责任感两个因素构建旅游者地方感与满意度关系模型,分析探讨了旅游者地方感、自我效能感、社会责任感和满意度的关系。在研究方法上,通过对世界遗产地苏州古典园林、黄山和三清山的问卷调查,利用AMOS软件进行结构方程模型分析。结果表明,旅游者地方感对旅游者自我效能感和旅游者社会责任感具有显著直接的正向影响,旅游者自我效能感和旅游者社会责任感分别对旅游者满意度具有显著直接的正向影响。这些为研究旅游者地方感与满意度之间的复杂心理关系提供了一种有效方法,这种复杂的心理关系对旅游目标的实现有着重要的影响。 相似文献
294.
河北邯郸钢铁冶炼区周边麦田土和小麦籽粒的多环芳烃含量及其组分谱特征 总被引:8,自引:6,他引:2
在大型邯郸钢铁公司周边不同样区的麦田成对采集表层土壤和成熟的小麦籽粒样品,检测US EPA优控的16种母体多环芳烃(polycyclic aromatic hydrocarbons,PAHs)的浓度和组分谱,确定当地麦田表土PAHs的空间分布特征、与总有机碳TOC分数的相关性.由此,初步开展PAHs源解析,并简单探讨小麦籽粒PAHs与表土PAHs的关联性.结果表明,麦田表土总PAHs平均中位数含量为398.9 ng·g-1(范围123.4~1 626.4 ng·g-1),根据丹麦的土壤质量标准,所有表土样品中PAHs总含量超过限值占18%,而苯并[a]芘含量超过限值的样品占总数的10%.表土PAHs组分谱以中、高环组分为主体.利用同分异构体特征比值进行初步源解析,显示煤与生物质燃烧和交通燃油(尾气)是当地PAHs主要混合排放源.各样区麦田表土TOC分数与PAHs总含量、与不同环数组分含量都呈现类似的显著正相关.邯郸钢铁公司周边麦田小麦籽粒的总PAHs平均中位数含量为27.0 ng·g-1(范围19.0~34.0 ng·g-1),PAHs含量较低且未超过欧盟与国内的相关食品卫生标准.小麦籽粒中优势低环组分占总体的84%,其组分谱分布与麦田表土有所不同,显示小麦籽粒的PAHs除去根部吸收、传输外,还存在大气干湿沉降通过叶表(气孔)进入小麦体内等其它输入途径. 相似文献
295.
Xue Fei Xi Lei Wang Jia Jun Hu Yu Shu Tang Yu Hu Xiao Hua Fu Ying Sun Yiu Fai Tsang Yan Nan Zhang Jin Hai Chen 《环境科学学报(英文版)》2014,26(12):2562-2570
Estuarine wetland, where freshwater mixes with salt water, comprises different regions(rivers and marine ecosystems) with significantly varying tidal salinities. Two sampling areas, ZXS and JS, were selected to investigate the effect of tidal salinity on soil respiration(SR). ZXS and JS were located in Zhongxia Shoal and Jiangyanan Shoal of Jiuduansha Wetland respectively, with similar elevation and plant species, but significantly different in salinity. The results showed that with almost identical plant biomass, the SR and soil microbial respiration(SMR) of the tidal wetland with lower salinity(JS) were significantly higher than those of the tidal wetland with higher salinity(ZXS)(p 〈 0.05). However, unlike SMR and SR, the difference in the soil microbial biomass(SMB) was not significant(p 〉 0.05)with the SMB of ZXS a little higher than that of JS. The higher SMR and SR of JS may be closely connected to the soil microbial community structures and amount of dominant bacteria. Abundant β- and γ-Proteobacteria and Actinobacteria in JS soil, which have strong heterotrophic metabolic capabilities, could be the main reason for higher SMR and SR,whereas a high number of ε-Proteobacteria in ZXS, some of which have carbon fixation ability, could be responsible for relatively lower carbon output. Path analysis indicated that soil salinity had the maximum negative total influencing coefficient with SMR among the various soil physical and chemical factors, suggesting that higher soil salinity, restricting highly heterotrophic bacteria, is the principle reason for lower SMR and SR in the ZXS. 相似文献
296.
硫氧同位素示踪南京北郊大气PM2.5中硫酸盐来源 总被引:3,自引:1,他引:2
采用EA-IRMS联用技术对2014年1月南京北郊大气细粒子(PM2.5)中硫酸盐的硫和氧同位素组成进行了分析,结合大气颗粒物化学组成,追溯南京北郊大气PM2.5中硫酸盐的来源,并评估了各污染源的贡献率.结果表明,2014年1月南京北郊硫酸盐气溶胶的硫同位素组成(δ34S)范围为2.7‰~6.4‰,平均值为5.0‰±0.9‰(n=16);氧同位素组成(δ18O)值范围为10.6‰~16.1‰,平均值为12.5‰±1.37‰(n=16).通过气溶胶与可能污染源的δ34S值对比和后向轨迹分析,得出结论:研究区域大气中硫同位素组成主要受当地燃煤中硫的影响,其次是远距离传输硫.此外,有低δ34S值硫源存在,但贡献比较小,可能来自生物成因硫.绝对主因子分析结果显示:人为成因硫和远距离传输硫贡献率分别为46.74%和31.54%. 相似文献
297.
Comparison of catalytic activity of two platinised TiO2 films towards the oxidation of organic pollutants 总被引:2,自引:0,他引:2
Two types of platinised TiO2 films, i.e., Pt-TiO2/ITO and Pt(TiO2)/ITO, were prepared by a procedure of dip-coating and subsequent photo-deposition, and photo-deposition and subsequent dip-coating, respectively. They were well characterized by DRS, XRD spectra, SEM microscopy and photoelectrochemical measurement. Their photocatalytic, dark catalytic and photoelectrocatalytic activities were investigated using formic acid as a model organic pollutants. Compared with pure TiO2/ITO film, the photocatalytic activity of the platinised TiO2 films were apparently improved. However, the improvement was considerably dependent on the preparation method of these films. Pt-TiO2/ITO not only possessed higher photocatalytic activity but also showed a dark catalytic activity towards HCOOH degradation. As a sequence, it was first emphasized that the dark catalytic effect of Pt-TiO2/ITO was partly responsible for degradation of formic acid in the photocatalytic oxidation process. Although the Pt(TiO2)/ITO film does not exhibit the dark catalytic activity, its photocatalytic degradation efficiencies towards HCOOH are higher than that of Pt-TiO2/ITO film. Therefore, in view of enhanced photocatalytic activity, the Pt(TiO2)/ITO was more favored than Pt-TiO2/ITO film. 相似文献
298.
China produces almost half of ceramic tiles in the world. However, serious air pollution and high energy consumption in the preparation of ceramic press-powders by traditional wet process (WP) have become major barriers for the sustainable development of ceramic tile manufacturing industry. A novel cleaner production process, named by the authors as Droplet-Powder Granulation Process (DPGP), was proposed and tested in this work. Droplet-powder granulator, a key facility of DPGP, was designed. In the granulator, ceramic suspension was directly sprayed to form fine suspension droplets and ceramic dry powder was simultaneously jetted and dispersed to enwrap, insulate and adsorb the suspension droplets so as to form coarse granules that were then rolled, tamped and dried into press-powders. Lab experiments of preparing press-powders by DPGP were carried out. The as-prepared DPGP press-powders consist of solid granules with nearly spherical shape and approximately normal grain size distribution, and present favorable flowability and relatively high bulk density, with the similar properties of the press-powders as those prepared by WP. Moreover, as compared with WP, DPGP can reduce both pollutant emission of 98% dust, 65% sulfur oxides and 71% nitrogen oxides and resource consumption of 24% energy and 69% water. Therefore, DPGP is an innovative approach for cleaner production of ceramic press-powders. 相似文献
299.
尝试用时间序列分析中的自适应滤波法对江河灾害性洪水进行预测,认为加权因子个数和自适应常数的确定是关键。以荆江沙市站1950~1995年的年最高水位资料为研究对象,借助计算机编程与计算,确定了最优加权因子个数和自适应常数,建立了适合于该站未来年最高水位的预测模型。预测结果与误差分析表明,自适应滤波法用于江河洪水预测是可行的。 相似文献
300.
资源代际管理与可持续发展 总被引:17,自引:0,他引:17
代际均衡发展是可持续发展战略的重要方面,代际均衡发展的物质基础是代际财富均衡。自然资源是代际财富均衡分配的主要内容,需要进行资源代际管理来保证可持续发展战略的实现。 相似文献