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871.
Poly(-caprolactone) (PCL) was blended with diatomaceous earth (diatomite) and irradiated with -rays to introduce cross-linking between PCL molecules or both components. The unwashed diatomite containing a little of a volatile component showed high efficiency of introduction of cross-linking, whereas that with no volatile component showed low efficiency of introduction of cross-linking. Elongational viscosity, melt viscosity, and modulus of PCL/diatomite blend irradiated at various doses were significantly improved. Enzymatic degradation of the PCL/diatomite blend became faster than that of the PCL, though that of the blend irradiated became slower.  相似文献   
872.
In a climate of limited resources, it is often necessary to prioritize restoration efforts geographically. The synoptic approach is an ecologically based tool for geographic prioritization of wetland protection and restoration efforts. The approach was specifically designed to incorporate best professional judgment in cases where information and resources are otherwise limited. Synoptic assessments calculate indices for functional criteria in subunits (watersheds, counties, etc.) of a region and then rank the subunits. Ranks can be visualized in region-scale maps which enable managers to identify areas where efforts optimize functional performance on a regional scale. In this paper, we develop a conceptual model for prioritizing watersheds whose wetlands can be restored to reduce total sediment yield at the watershed outlet. The conceptual model is designed to rank watersheds but not individual wetlands within a watershed. The synoptic approach is valid for applying the sediment yield reduction model because there is high demand for prioritizing disturbed wetlands for restoration, but there is limited, quantitative, accurate information available with which to make decisions. Furthermore, the cost of creating a comprehensive database is prohibitively high. Finally, because the model will be used for planning purposes, and, specifically, for prioritizing based on multiple decisions rather than optimizing a single decision, the consequence of prioritization errors is low. Model results cannot be treated as scientific findings. The conclusions of an assessment are based on judgement, but this judgement is guided by scientific principles and a general understanding of relevant ecological processes. The conceptual model was developed as the first step towards prioritizing of wetland restoration for sediment yield reduction in US EPA Region 4.  相似文献   
873.
The results of a study on morphophysiological variation in fish inhabiting a subarctic lake exposed to chronic industrial pollution are described using an example of cisco, Coregonus lavaretus. It is shown that indices of the heart, liver, kidneys, gills, and fatness in these fish are increased significantly and have retained increased values for the past 20 years. The observed changes are analyzed on the basis of biochemical data. The results of studies on the dynamics of hematological parameters in fish are used for characterizing the development of toxicosis. Adaptive rearrangements associated with an increase in the metabolic rate and the activation of protective systems in the fish are explained in the context of S.S. Schvarts' concept. The idea is proposed that the additional energy cost of detoxification may be responsible for morphophysiological variation in fish under conditions of water pollution.  相似文献   
874.
对铁碳处理硝基酚废水的研究   总被引:1,自引:0,他引:1  
铁碳降解水中难降解有机污染物的影响因素、最佳工艺参数及处理效果;初步探讨了氧化降解污染物的作用机理;通过分析污染物降解的中间产物,提出了污染物降解的可能途径.探讨了pH、铁碳用量、温度以及锰矿物的粒径等对处理效果的影响,在最佳的工艺条件下,CODCr的去除率达到95%以上,TOC测定表明:大部分硝基酚被氧化降解为H2O和CO2.对硝基酚的降解途径主要是微电解将对硝基酚还原为对氨基酚,对氨基酚在酸性条件下被软锰矿氧化为H2O和CO2做探索性研究.  相似文献   
875.
制备了一种铁碳基/过渡金属复合催化剂,其物质摩尔配比为Fe:C:TiO2:MnO2:ZnO=2:1:1:1:0.3,使用该催化剂拟定了二次催化—固定床生物氧化降解流程。在pH=6、温度=90℃的条件下,用该流程处理煤化工工业所产生的洗煤气净化脱酚、蒸氨剩余废水,在无需对原废水进行稀释的前提下可很好地对此废水进行处理,使处理后的出水指标达到《污水综合排放标准》(GB89r78—1966)中规定的二级排放标准。  相似文献   
876.
郭绍义 《资源开发与市场》2007,23(9):769-771,777
介绍了利用溶胶凝胶方法制备铜系催化剂,并考察了制备过程中各个工艺参数对铜系催化剂稳定性的影响。通过优化催化剂的设计和制备方法,可有效地改善Cu^2+的溶出问题,使该类催化剂具有广阔的应用前景。  相似文献   
877.
随着社会经济的发展人地矛盾变得越发突出,已经成为制约城市经济进一步发展的桎梏.泉州市在社会经济快速发展的同时面临着土地资源严重紧缺的问题,亟需对其市域土地承载力进行研究,并用来指导城市的发展,从生态敏感性的视角,通过对泉州市域的生态用地和城建用地的划分,在以保护生态用地为前提的基础上,对其生态用地规模和城市用地规模进行测算,最后分别按照国际和国内两种指标来测算其土地资源承载力.  相似文献   
878.
污泥掺烧技术在煤粉炉上应用的试验研究   总被引:2,自引:0,他引:2  
通过污泥掺烧技术在煤粉炉上的应用试验,得出污泥的含水率对锅炉制粉系统的影响.掺烧前后对炉膛温度没有大的影响,随着污泥比例的增加,燃烧效率下降,烟尘浓度和SO2浓度降低.  相似文献   
879.
CO2 storage capacity estimation: Methodology and gaps   总被引:3,自引:0,他引:3  
Implementation of CO2 capture and geological storage (CCGS) technology at the scale needed to achieve a significant and meaningful reduction in CO2 emissions requires knowledge of the available CO2 storage capacity. CO2 storage capacity assessments may be conducted at various scales—in decreasing order of size and increasing order of resolution: country, basin, regional, local and site-specific. Estimation of the CO2 storage capacity in depleted oil and gas reservoirs is straightforward and is based on recoverable reserves, reservoir properties and in situ CO2 characteristics. In the case of CO2-EOR, the CO2 storage capacity can be roughly evaluated on the basis of worldwide field experience or more accurately through numerical simulations. Determination of the theoretical CO2 storage capacity in coal beds is based on coal thickness and CO2 adsorption isotherms, and recovery and completion factors. Evaluation of the CO2 storage capacity in deep saline aquifers is very complex because four trapping mechanisms that act at different rates are involved and, at times, all mechanisms may be operating simultaneously. The level of detail and resolution required in the data make reliable and accurate estimation of CO2 storage capacity in deep saline aquifers practical only at the local and site-specific scales. This paper follows a previous one on issues and development of standards for CO2 storage capacity estimation, and provides a clear set of definitions and methodologies for the assessment of CO2 storage capacity in geological media. Notwithstanding the defined methodologies suggested for estimating CO2 storage capacity, major challenges lie ahead because of lack of data, particularly for coal beds and deep saline aquifers, lack of knowledge about the coefficients that reduce storage capacity from theoretical to effective and to practical, and lack of knowledge about the interplay between various trapping mechanisms at work in deep saline aquifers.  相似文献   
880.
利用纳米材料TiO2对室内甲醛进行了治理研究。测定了TiO2在不同吸附剂量、吸附时间时的吸附效率、穿透时间和吸附容量。将TiO2、活性炭对甲醛的吸附效果进行了对比,结果表明,纳米材料TiO2对甲醛的吸附率比相同质量的活性炭高10%-15%;当吸附时间为13h时,TiO2对甲醛的吸附量比活性炭高28%;穿透时间比活性炭长2h。利用SEM图谱进行了机理分析。  相似文献   
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