Charge‐transfer chromatographic study of the interaction of commercial pesticides with hydroxypropyl‐β‐cyclodextrin

The interaction between 33 commercial pesticides with hydroxypropyI‐β‐cyclodextrin (HPBCD) was studied by charge‐transfer reversed‐phase thin‐layer chromatography using aqueous sodium chloride solutions as eluents. Each pesticide interacted with HPBCD, their lipophilicity linearly decreased with increasing HPBCD concentration, the pesticide ‐ HPBCD complex (probably inclusion complex) always being more hydrophilic than the uncomplexed pesticide. In many cases the retention of pesticide increased with increasing concentration of salt in the eluent. This effect can be tentatively explained by the suppression of the dissociation of the polar groups in the solute molecules resulting in increased apparent lipophilicity. No significant correlation was found between lipophilicity and complex stability or between salting‐out effect and lipophilicity, that is other than hydrophobic forces are involved in the pesticide ‐ HPBCD interaction.     

Facilitating sustainable development in Chile: a survey of suitable energy technologies

Sustainable development in developing countries is the main aim of the Kyoto Protocol's Clean Development Mechanism (CDM). However, in the present context, uncertainty prevails as to whether the CDM is actually achieving its aims in terms of achieving sustainable development and to what extent. Chile has several renewable energy and energy efficiency options with significant greenhouse gas (GHG) emissions abatement potential that are not yet financially and economically competitive. In order to be able to identify potential CDM projects and to formulate a series of possible investment strategies with a sustainable development component, it is crucial to establish a clear understanding of the host country's needs and priorities and the suitable sustainable energy technologies to meet these needs. The main scope of this paper is to present results obtained from an elaborated stakeholder assessment on Chile's high priority energy needs and sustainable energy technologies fulfilling these needs in order to assist Chile in finding ways of encouraging technology transfer that would contribute to low-carbon sustainable energy development.     

植物提取液对城市垃圾中转站恶臭物质的处理效果

对某2种商品植物除臭剂（代号A和C）进行了NH3和H2S的去除效果实验,确定了其最佳的使用条件;并实验了植物提取液对城市垃圾中转站渗滤液和实际中转站中恶臭气体的处理效果。结果显示,终浓度为0.85 g/m3的植物提取液A对NH3和H2S的去除率最高可达39.9%和92.31%;在城市垃圾中转站试验中,1.02 g/m3的植物提取液A结合超声波雾化装置对NH3和H2S的去除率可达66.67%和96.67%。研究表明利用植物提取液可以有效降低城市垃圾中转站恶臭污染物浓度,而采用超声波雾化装置效果更好。     

北京城市发展新区土地利用景观格局分析

以北京南部城市发展新区典型代表———房山、大兴、通州3处作为研究区,运用马尔科夫转移矩阵和景观格局指数的方法,进行土地利用变化和景观格局分析。通过对2001—2006年、2006—2011年两个时段的对比分析,发现2001—2006年研究区存在草地、林地、耕地等非建设用地类型面积下降,建设用地面积上升的趋势,且2006—2011年该趋势更加明显。结果表明研究区自然景观向人文景观变革迅速,并面临着后备土地资源不足等问题,亟需调整土地利用方式并优化景观系统空间格局。     

长江三角洲城市内河环境治理的居民支付意愿比较研究 ——上海、南京与杭州实例调查

应用意愿价值评估法(CVM)的技术调查上海、南京和杭州城市内河环境治理的居民支付意愿,并探讨研究结果是否在城市间保持稳定.基于1258份问卷的统计分析,结果显示:上海、南京和杭州居民的支付意愿均值分别为20.5,25.4,20.3元/(户×月);进一步的线性对数模型分析结果表明,收入、环境意识等变量在3城市都呈现显著影响,而户籍、教育等因素在各城市模型中存在显著性差异;3城市混合数据模型显示,南京样本支付意愿显著高于其他2城市样本,杭州与上海调查样本无显著性差异.上述结果揭示了不同城市居民对城市内河治理的支付意愿呈现稳定性,为意愿价值评估法在我国不同区域间的“效益转移”研究提供了实证支持.但另一方面,参数模型表现出一定的差异,需要对模型作进一步的优化.     

东平湖水生植物的衰退及南水北调工程对其影响

对南水北调东线工程中的调蓄枢纽东平湖进行了考察.发现,目前东平湖仅存水生植物18种,覆盖度为51%.简要分析了1979年至今东平湖水生植物的衰退状况及其形成驱动力.根据调水状态下东平湖水环境将会发生的变化,系统探讨了调水工程对东平湖水生植物的可能影响.结果表明,二期工程物种多样性变化不大,分布面积将会有不同程度的下降,群落总体的断带状分布将更为典型;三期工程物种多样性将明显下降,种群结构趋向单一化,沉水植物仍将成为优势种群.     

区域农村土地市场发育的农户行为响应与农业土地利用变化——以江苏省苏州市、南京市、扬州市村庄及农户调查为例

在江苏省苏州市、南京市、扬州市各自选择了2个村的基础上,运用对240个农户的抽样调查资料,建立了区域农业土地利用变化分析的数量经济模型,较为深入地分析了农村土地流转市场引导下的农户行为对于农业土地利用变化的影响。研究结果表明,在农户决策行为起主导作用的前提下,农业土地利用正在逐步由传统的大田作物向效益更高的经济作物和水产养殖等地类转化;农户家庭非农就业水平的提高有效地推进了这一转化;同时,农户受教育水平的高低以及政府行为都在一定程度上影响着农业土地利用变化。最后从区域非农产业和城镇化发展、深化农村土地产权的物权化改革、农村社会保障制度的完善、建立农村土地流转中介机制、进一步规范政府行为及积极推进农村户籍制度改革等方面提出了一些政策性建议。     

基于粒子群算法的城市垃圾中转站的空间布局研究

随着城市化的进程，垃圾处理设施成为影响城市化质量的重要指标。依据人们实际所关注的垃圾处理设施的总成本和负效应两个因素，在前人研究的基础上，建立了垃圾收运多目标模型，使得总成本和负效应最优化。根据模型设计了粒子群算法，该算法属于智能算法，且精度高，收敛快，在许多领域也得到广泛应用。用设计的粒子群算法并结合案例求出了Pareto最优解，给出三种决策方案，验证了模型和算法的有效性和可行性，为决策者提供了一种理论参考。     

Arsenic rich iron plaque on macrophyte roots - an ecotoxicological risk?

Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcóllar mine spill (Spain), residual arsenic contamination left in seasonal wetland habitats has been identified in this form by scanning electron microscopy. Total digestion has determined arsenic concentrations in thoroughly washed ‘root + plaque’ material in excess of 1000 mg kg⁻¹, and further analysis using X-ray absorption spectroscopy suggests arsenic exists as both arsenate and arsenite. Certain herbivorous species feed on rhizomes and bulbs of macrophytes in a wide range of global environments, and the ecotoxicological impact of consuming arsenic rich iron plaque associated with such food items remains to be quantified. Here, greylag geese which feed on Scirpus maritimus rhizome and bulb material in areas affected by the Aznalcóllar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque.     

Strategies for improving the photocatalytic performance of metal-organic frameworks for CO2 reduction: A review

Photocatalytic CO₂ reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels. Numerous attempts have been made to produce effective and efficient photocatalysts for CO₂ reduction. In contrast, the selection of competitive catalysts continues to be a substantial hindrance and a considerable difficulty in the development of photocatalytic CO₂ reduction. It is vital to emphasize different techniques for building effective photocatalysts to improve CO₂ reduction performance in order to achieve a long-term sustainability. Metal-organic frameworks (MOFs) are recently emerging as a new type of photocatalysts for CO₂ reduction due to their excellent CO₂ adsorption capability and unique structural characteristics. This review examines the most recent breakthroughs in various techniques for modifying MOFs in order to improve their efficiency of photocatalytic CO₂ reduction. The advantages of MOFs using as photocatalysts are summarized, followed by different methods for enhancing their effectiveness for photocatalytic CO₂ reduction via partial ion exchange of metal clusters, design of bimetal clusters, the modification of organic linkers, and the embedding of metal complexes. For integrating MOFs with semiconductors, metallic nanoparticles (NPs), and other materials, a number of different approaches have been also reviewed. The final section of this review discusses the existing challenges and future prospects of MOFs as photocatalysts for CO₂ reduction. Hopefully, this review can stimulate intensive research on the rational design and development of more effective MOF-based photocatalysts for visible-light driven CO₂ conversion.