基于云模型和熵权法的巢湖流域防洪减灾能力评估

防洪减灾能力评估是洪涝灾害管理急需解决的重大问题之一。从防洪除涝能力、监测预警能力、抢险救灾能力及灾害管理能力4个方面来构建指标体系,建立基于云模型和熵权法的巢湖流域防洪减灾能力评估模型,对整个流域以及流域内各县市的防洪减灾能力进行评估,并与通过组合赋权法及最优分割法得到的结果进行验证对比。以期为防洪减灾能力评估提供新的思路,对巢湖流域的防洪减灾能力建设提供科学依据。研究结果表明:巢湖流域整体防洪减灾能力属于中等偏上水平,但流域内部差异明显;其中合肥市辖区、和县的防洪减灾能力属于高水平;巢湖市、含山县处于中等水平;肥西县和庐江县位于较低水平;肥东县、无为县、舒城县的防洪减灾能力则最低。     

宝钢电厂3号火电机组电除尘系统改造

结合工程实例,从除尘器入口烟气降温、除尘器设备本体、引风机三个方面提出了大型钢铁企业火电机组电除尘系统的改造思路,根据对改造后近两年多运行情况的调研,以实际效果验证了改造的成功,为大型钢铁企业类似自备火电机组的电除尘系统改造提供了借鉴。     

Catalytic hydrothermal depolymerization of nylon 6

Depolymerization of nylon 6 to produce ε-caprolactam using an environmentally friendly heteropoly acid catalyst was studied at temperatures between 553 and 603 K in water. The products of depolymerization were analyzed qualitatively and quantitatively by means of mass spectrometry and high-performance liquid chromatography. The results showed that the depolymerized product was mainly ε-caprolactam with a little 6-aminocaproic acid and oligomers. The phosphotungstic heteropoly acid used as a catalyst can improve the hydrolysis rate and yield of ε-caprolactam. The optimum hydrolysis conditions for ε-caprolactam yield were as follows: phosphotungstic heteropoly acid content, 3%; reaction temperature, 573 K; and reaction time, 85 min. Under these conditions, the yield of ε-caprolactam was 77.96%. In the temperature range 553–603 K, the activation energy of 3% phosphotungstic heteropoly acid-catalyzed depolymerization was evaluated as 77.38 kJ/mol, which is lower than the 86.64 kJ/mol value for no catalyst.     

Rapid assessment of sustainability in Mainland China

This paper presents an approach for rapid assessment of sustainability for Mainland China based on a multilayer index system. Efficient assessment is conducted with the basic mapping units at county and city levels. After evaluating a comprehensive sustainable development index, SDI, for each unit, five rankings of sustainability are determined, and a zonation map produced. Regional characteristics and differences are interpreted through macro-analysis of the spatial variation in SDI. A sensitivity analysis is performed by which the weights of the sub-indices are altered by ±20%, and SDI re-evaluated; the resulting grades remain the same, thus confirming the robustness of the technique. Moreover, the accuracy of the proposed approach is indirectly validated by comparison with assessment results from an alternative systems analysis method. It is found that major conurbations such as Beijing have relatively high levels of sustainability, whereas provinces in central and western China require investment to improve their sustainability.     

海水中同位素Ra分析方法比较研究

对分析海水中Ra同位素的小体积(约10~20 L)alpha能谱法和大体积(200~500 L)Gamma能谱法进行了对比研究。取样水域含盖了零盐度河流(徐六泾)、近岸水体和开阔大洋,结果表明:不论在低盐度的近岸水体,还是在高盐度的外海水两种方法的结果在误差范围内可以认为是基本一致的。另外,在大体积Gamma能谱法研究中,发现富集海水所用的纤维量和过滤海水体积等因素的变化对于该方法富集效率和结果产生了影响;同时,验证了大体积方法本身的富集有效性。     

A building-based data capture and data mining technique for air quality assessment

Recently, a building-based air quality model system which can predict air quality in front of individual buildings along both sides of a road has been developed. Using the Macau Peninsula as a case study, this paper shows the advantages of building-based model system in data capture and data mining. Compared with the traditional grid-based model systems with input/output spatial resolutions of 1–2 km, the building-based approach can extract the street configuration and traffic data building by building and therefore, can capture the complex spatial variation of traffic emission, urban geometry, and air pollution. The non-homogeneous distribution of air pollution in the Macau Peninsula was modeled in a high-spatial resolution of 319 receptors·km⁻². The spatial relationship among air quality, traffic flow, and urban geometry in the historic urban area is investigated. The study shows that the building-based approach may open an innovative methodology in data mining of urban spatial data for environmental assessment. The results are particularly useful to urban planners when they need to consider the influences of urban form on street environment.     

火山喷发的气体灾害

火山喷发是一种壮观的自然景象,其喷发类型多种多样。火山喷发不仅可以改变地貌,带来一些矿产资源,更多的是给自然界带来灾害。火山喷发一般都同时喷出气体,强火山喷发巨量的气体喷入空中,会给全球气候和环境造成极大的灾害。     

Polybrominated diphenyl ethers in sediments of the Daliao River Estuary, China: levels, distribution and their influencing factors

The concentrations, compositional profiles, possible sources of polybrominated diphenyl ethers (PBDEs) in sediments of the Daliao River Estuary as well as the factors influencing the distribution of PBDEs were investigated. The total concentrations of PBDEs ranged from 0.13 to 1.98 ng g⁻¹ d.w. BDE209 was the dominating congener in all sediment samples, indicating the pollution of PBDEs in the Daliao River Estuary mainly came from the use of deca-BDE commercial mixtures. The intrusion of sea waters promoted the deposition of the colloid-associated PBDEs in the estuary. There were significantly negative correlations between PBDE concentration in sediment with pH value and salinity in the bottom water. The higher river flow in the flood season (summer) obviously accelerated the transport of PBDEs, and thereby increased the risk of PBDE contamination to the deep ocean. Moreover, a positive correlation between TOC and PBDE distributions was observed, suggesting that TOC regulated the distributions of PBDEs in sediments of Daliao River Estuary.     

利用厌氧菌发酵产物处理含铅废水及机理研究

针对传统方法去除废水中重金属铅的缺陷,利用4株厌氧微生物的发酵产物,在不同投加量、pH、温度和反应时间下研究该产物的除铅效果。通过正交实验确定了微生物发酵产物对含铅废水处理的最佳反应条件为:发酵产物投加量为0.5 g,反应时间为20 min,pH=6,温度20℃,铅的去除率99.4%以上,并用蓄电池厂的实际废水进行验证实验,获得相同的效果;同时通过扫描电子显微镜和X-射线能量散射光谱分析厌氧细菌代谢的混合物成分,对去除机理进行了初步探讨,为生物技术处理含铅废水提供了一种新方法和理论依据。     

Fluorescence of sediment humic substance and its effect on the sorption of selected endocrine disruptors

Humic substances (HS) have a critical influence on the sorption of organic contaminants by soils and sediments. This paper describes investigations into the sorption behavior of three representative endocrine disruptors, bisphenol A (BPA), 17beta-estradiol (E2), and 17alpha-ethynylestradiol (EE2), onto sediments and HS extracted sediments using a batch technique. The organic carbon-normalized partition coefficients (K(oc)) for the extracted HS (K(oc)(hs)) were calculated, and the fluorescence spectra of the HS extraced from different sediment samples were gained using excitation/emission matrix (EEM). Particular attention was paid to the correlations between the fluorescence characteristics of HS and the log K(oc)(hs) of selected endocrine disruptors. The results show that the log K(oc)(hs) values range from 3.14 to 4.09 for BPA, from 3.47 to 4.33 for E2, and from 3.65 to 4.32 for EE2. Two characteristic excitation-emission peaks were observed for HS samples extracted from sediments. They are located at Ex/Em=250-260 nm/400-450 nm (peak alpha') and Ex/Em=310-330 nm/390-400 nm (peak alpha) respectively. The alpha' and alpha peak relative intensities I(alpha')/I(alpha) vary from 0.46 to 1.64 for different extracted HS samples. The similarity between fulvic acids (FA) Ex/Em pairs and those observed for HS indicates that FA is the predominant fraction of HS extracted from sediments. Moreover, the log K(oc)(hs) values of BPA, E2, and EE2 have a negative linear correlation to I(alpha')/I(alpha) values. Peak alpha is often attributed to relatively stable and high molecular weight aromatic fulvic-like matter. Therefore, the result presented here reveals that the abundance of aromatic rings in HS molecular structure plays a critical role in the sorption of selected endocrine disruptors.