基于体验模式的景观美学评价技术及应用

由于景观美学评价的主观特性，虽经五十多年的探索，各国学者仍未能就景观美学评价的理论达成共识。基于体验模式的评价技术更由于其凸显的主观元素而被多数研究者排除在科学评价体系之外。文章综合应用生态学、心理学、美学、地理信息系统（GIS）等学科的知识，理论研究和实证分析相结合，探究了该评价技术的科学合理性。研究以武汉后官湖地区为个案，采用网格布点法，借助地理<br />信息系统（GIS）技术的支持，运用基于体验模式的评价技术，完成对研究区的景观美学评价。结果显示，研究区内景观美学评分等级的分布与其景观元素类别的分布表现出较好的一致性，这在一定程度上验证了该评价技术的科学合理性。另外，结论分析了该技术环节上存<br />在的主要问题及方法上的优劣

Environmental exposure to arsenic may reduce human semen quality: associations derived from a Chinese cross-sectional study

<strong>Background:</strong> Recent observations in in vitro and in vivo models suggest that arsenic (As) is an endocrine disruptor at environmentally-relevant levels. When exposed to As, male rats and mice show steroidogenic dysfunction that can lead to infertility. However, the possible effects of As on human male semen quality remain obscure.<br /><strong>Methods:</strong> We monitored the profile of As species in the urine of a reproductive-age human cohort and assessed its association with semen quality. Men (n = 96) were recruited in an infertility clinic from July 2009 to August 2010 in the Affiliated Hospital of Chongqing Institute for Population and Family Planning. Five urinary As species were analyzed by high-performance liquid chromatography coupled with inductively coupled plasma mass<br />spectrometry (HPLC-ICP-MS). Clinical information on the semen volume, sperm concentration and motility was employed to catalogue and evaluate semen quality according to WHO guidelines. As species concentrations in addition to other continuous variables were dichotomized by the medians and modelled as categorical variables in order to explore using the binary logistic regression possible associations between As exposure and semen quality.<br /><strong>Results:</strong> Urinary concentrations (geometric mean &plusmn; SD, &mu;g g-1 creatinine) of different As species were 7.49 (&plusmn;24.8) for<br />AsB, 20.9 (&plusmn;13.7) for DMA, 2.77 (&plusmn;3.33) for MMA, and 4.03 (&plusmn;3.67) for Asi (AsiIII and AsiV). DMA concentrations above the<br />median were significantly associated with below-reference sperm concentrations (P =0.02) after adjusting for age, body<br />mass index (BMI), abstinence, smoking and drinking habits. In addition, smoking was positively associated with MMA.<br /><strong>Conclusion:</strong> Reduced parameters in human semen quality are positively associated with As exposure in a reproductiveage<br />Chinese cohort

Urban phosphorus metabolism through food consumption: the case of China

Urbanization has significant impacts on local, regional, and global biogeochemical cycles,including through nutrient enrichment by food consumption, and especially in rapidly urbanizing countries. This article presents a time-series estimation of phosphorus (P) metabolism through food consumption in Chinese cities and examines its relationship to income level during the period 1985&ndash;2006. Our results show that approximately 39% of the total dietary P inflow is exported through direct sewage discharge without treatment, 35% is exported via the output of solid human excreta, 7% is exported through sewage sludge landfill, and 19% is left within urban areas. The total inflow of dietary P to urban systems increases with per capita disposable income level. Furthermore, the ratio of dietary P remaining in urban systems to total dietary P inflow, the dietary P remaining in urban systems per capita,and the dietary P remaining per unit urban built-up area respond in an inverted U shape to increases in per capita disposable income; the per capita outflow of dietary P shows a U-shaped response. These relationships may indicate that the impact of urban dietary P on urban environmental systems follows the traditional environmental Kuznets curve, while the environmental impact of urban dietary P on surrounding nonurban ecosystems initially decreases but then increases with the rising income of urban residents

浸润线高度对垂直潜流湿地处理效果的影响研究

针对污染物浓度较高的猪场沼液,开展了不同浸润线高度下垂直潜流湿地处理效果的对比研究。试验结果表明:湿地浸润线可改变湿地填料层中的溶解氧分布和水力流态,从而造成了3种类型湿地系统对猪场沼液处理效果的差异;在不同水力负荷下,中浸润线垂直潜流湿地(VSSF-M)对猪场沼液中各项污染物的去除效果均好于低浸润线垂直潜流湿地(VSSF-L)和高浸润线垂直潜流湿地(VSSF-H);中浸润线垂直潜流湿地利用溶解氧梯度在填料层内实现了好氧区、缺氧区和厌氧区的共存,从而使硝化作用与反硝化作用在同一系统内完成,提高了系统的脱氮能力;中浸润线垂直潜流湿地系统还可适当增大系统的水力停留时间(HRT),并可优化水力流态,从而进一步改善湿地系统的净化效果。因此,结合处理效果和出水水质的稳定性,中浸润线垂直潜流湿地对浓度较高的猪场沼液具有较高的去除效率

The ratio of food-to-microorganism (F/M) on membrane fouling of anaerobic membrane bioreactors treating low-strength wastewater

Anaerobic membrane bioreactors (AnMBRs) show great promise for wastewater treatment. However, membrane fouling is still a major limiting factor for industrial application. There is little information focusing on membrane fouling of AnMBRs treating low-strength municipal wastewater. The food-to-microorganism (F/M) ratio is a controllable parameter found to significantly influence system performance and fouling in aerobic membrane bioreactors (MBRs). In this study, two lab-scale AnMBRs (named as HAnMBR and LAnMBR) were comparably run under high and low F/M ratios of 3.8&nbsp;g&nbsp;COD/g&nbsp;MLSS.d and 0.1&nbsp;g&nbsp;COD/g&nbsp;MLSS.d, respectively. The impact of the F/M ratio on the performance of AnMBRs was systematically evaluated, especially with regard to fouling. The results showed that cake resistance was responsible for over 98% of the total fouling, and membrane fouling in the HAnMBR was more severe than that in the LAnMBR. HAnMBR had higher amounts of soluble microbial products and higher tightly-bound to loosely-bound extracellular polymeric substance ratio in its cake layer accounted for a higher cake resistance. The larger amount of fine particles in the HAnMBR also contributed to more serious fouling. Membrane filtration deteriorated sludge bioflocculation, which in turn accelerated fouling

Incorporation of in situ exposure and biomarkers response in clams Ruditapes philippinarum for assessment of metal pollution in coastal areas from the Maluan Bay of China

The clams <em>Ruditapes philippinarum</em> were used to assess the impact of metal contaminants when transplanted to seven study sites along the Maluan Bay (China). Metal concentrations in digestive gland tissues of clams after 7-day in situ cage exposure were determined in conjunction with antioxidant enzyme activities. The results showed the importance of specific antioxidant biomarkers to assess complex pollutant mixtures and their good correlations to the pollutant compositions of deployment sites. Multivariate analysis indicated causal relationship between the chemicals at each study site and the biochemical &ldquo;response&rdquo; of the caged clams at these sites and demonstrated the potential presence of two different contaminant sources. This study suggested that the incorporation of tissue residue analysis with biomarkers response in caged clams together with factor analysis can be a useful biomonitoring tool for the identification of causal toxic pollutants and the assessment of complex metal pollutions in marine coastal environment

固相萃取-高效液相色谱-串联质谱测定九龙江流域水中药品和个人护理用品

<p>针对6大类共15种药品和个人护理用品(pharmaceuticals and personal care products,PPCPs)建立了固相萃取(SPE)-高效液相色谱串联质谱检测(HPLC-MS/MS)的分析方法,并利用该方法,研究九龙江流域水体中PPCPs的污染现状.通过优化SPE、HPLC和MS的参数,提高了分析方法的灵敏度和准确性,所建立的方法对15种PPCPs的检出限和定量限分别为0.008 20～3.20 ng/L和0.028 0～10.5 ng/L.九龙江西溪和北溪各8个站位水样中PPCPs的研究结果表明,11种目标PPCPs都有不同程度的检出,其中三氯生和三氯卡班的检出率均为100％,布洛芬、美多心安、四环素、诺氟沙星和环丙沙星的检出率分别为93.8％、93.8％、68.8％、68.8％和50％;值得注意的是,九龙江北溪上游布洛芬和四环素的质量浓度高达65.1和106 ng/L.结果表明,九龙江流域PPCPs污染状况需引起进一步关注.</p

长江三角洲城市群区域滨海湿地利用时空变化特征

应用遥感和地理信息系统技术，以研究区遥感影像为主要数据源，研究了1990～2000 年和2000～2005 年间长江三角洲城市群区域围海造地行为下滨海湿地利用的时空演变特征。围海造地在不同城市化发展时期分别为农业用地和建设用地扩张所需。以海岸线为基准，通过分别向陆地和向海洋方向进行滨海湿地分区，每个方向设立7 个缓冲带，靠近海岸线的前6 个缓冲带宽1 km，第7 个缓冲带宽10 km。结果表明，1990～2000 年期间，围海造地以农业用地扩张为主，其平均年扩张速率为48.9 km2/a，明显大于建设用地的平均年扩张速率(28.2km2/a)；而2000～2005 年期间，建设用地成为围海造地的主要目的，建设用地平均年扩张速率大幅增大至91.8km2/a，而农业用地平均年扩张率仅为4.2 km2/a。在空间分布上，1990～2000 年期间，农业用地平均年扩张百分率最大值出现在距海岸线5 km的陆地缓冲区；但在2000～2005 年期间，各陆地缓冲区农业用地面积在减少，其平均年扩张百分率为－1.3%/a；而建设用地在各缓冲区的平均年扩张百分率由1990～2000 年期间的0.62%/a 增大为2000～2005 年期间的2.66%/a。对长江三角洲滨海湿地土地流转驱动力的分析表明，城市化是建设用地扩张的重要驱动力；一些天然滨海湿地直接转变为建设用地，两个时期建设用地净扩张区域相同，即距海岸线1～3 km和＞6 km陆地缓冲带；还有一些天然滨海湿地，如滩涂，被用于水产养殖，而转变为人工湿地，在1990～2000 年期间，农业用地的扩张区域是距海岸线4～6 km的陆地缓冲带，在2000～2005 年期间，农业用地的扩张区域是1～3 km的近海缓冲带