固态反应法制备FeHY催化剂及其催化降解活性艳蓝的性能研究

分别以NaY、NH4Y和HY沸石为载体,以乙酰丙酮铁为铁源,采用固态反应法制备了铁负载量均为10%（w）的FeNaY-10、FeNH4Y-10和FeHY-10催化剂。考察了各催化剂对活性艳蓝（KN-R）的降解效果,其中FeHY-10的催化降解效果最佳。采用XRD和FTIR技术对FeHY-10催化剂进行表征。表征结果显示,FeHY催化剂晶体结构仍然保持了Y分子筛特有的孔道结构,铁物种在Y 分子筛表面高度分散。催化降解实验表明,催化降解KN-R的最佳工艺条件为KN-R溶液（质量浓度为300 mg/L）加入量为50 mL、溶液pH为2、催化剂FeHY-25（铁负载量为25%（w））加入量为0.281 3 g、H2O2质量浓度为6.356 g/L、降解温度为35 ℃、降解时间为140 min,在此工艺条件下FeHY催化剂对KN-R的降解率为97.4%。     

How do local communities adapt to climate changes along heavily damaged coasts? A Stakeholder Delphi study in Ky Anh (Central Vietnam)

The Central Vietnamese coast faces increasing impacts on the local livelihoods of coastal communities as a result of the increasing natural hazards which include tropical storms, heavy rains, and floods. A challenge for the local populations is improving their adaptation capacity to climate change hazards in a sustainable way. This study deals with the impacts of climate change-associated hazards and adaptation capacity in coastal communes of the Ky Anh district, Ha Tinh province along the coast in Central Vietnam. A combination of the Stakeholder Delphi technique and the DPSIR (drivers–pressures–states–impacts–responses) framework was used. Delphi questionnaires allowed assessing the consensus among the respondents of a stakeholder group. Twenty questions and 20 statements were listed reflecting the DPSIR components. Thirty-six panel members, which were randomly selected from four stakeholder groups which included local authorities, farmers, fishermen, and fish traders, were involved in a two-round Delphi process. The results show that, both agricultural and non-agricultural sectors are main drivers (D); migration, calamities, population growth, mineral mining, aquaculture processing, and agriculture are main pressures (P); changes in the frequency of extreme weather events, increasing intensity of storms, floods, and droughts indicate main states (S); changes in agricultural land use and productivity are main impacts (I); construction of and upgrading dykes and irrigation systems should be the principal responses (R) in the vision of the local stakeholders. The Kendall’s W value for the second round is 0.681, indicating a high degree of consensus among the panel members and confidence in the ranks. Overall, the study advocates developing sustainable ecosystems, an upgraded New Rural Planning, and renewable energy strategies as the main local adaptations to climate change hazards in this area.     

基于MODIS NDVI的攀枝花市植被覆盖变化及其驱动力#br#

攀枝花市位于金沙江与雅砻江的交汇处是长江上游生态脆弱区,也是天然林保护工程和退耕还林工程等的重点实施区。基于2001~2010年MODIS NDVI数据,以及同时期的气象数据和其他辅助数据,利用最大值合成法（MVC）、趋势分析法以及线性相关分析等方法研究了攀枝花市植被覆盖时空变化及其与气候因素和人类活动的关系。研究结果表明：攀枝花市植被覆盖整体较高,属于高植被覆盖区域,年际尺度上,植被覆盖呈上升的趋势,增长速率为0.02/10 a;从年内来看,9月NDVI达到最大值,NDVI最小值出现在3月;植被覆盖在水平空间上呈“南低北高”的分布特征,并在垂直空间上呈现出显著的差异性,研究区植被覆盖分别在海拔2 000~3 000 m、坡度30°~40°达到最大值;受水热条件的影响,阴坡（0°~45°, 315°~360°）植被覆盖高于阳坡（135°~225°）,而平地（-1°）植被覆盖度最低;就整个研究区而言,植被退化的面积与增加的面积分别占0.7%和44.4%,增加的面积远大于退化的面积;年际尺度上植被受气温的影响高于受降水的影响;大规模生态工程建设是研究区植被覆盖增加的主要驱动因素。 关键词： 植被覆盖变化;归一化植被指数;气候变化;人类活动;攀枝花市     

Water Transport in Polylactide and Polylactide/Montmorillonite Composites

Polylactide–montmorillonite composites were fabricated by melt-blending followed by compression molding, and water permeability of the composites was studied by both experiments and theoretical models. The water permeation in composites decreases with increasing concentration of montmorillonite. Specifically, at a concentration of 10 wt% of montmorillonite, the water permeation is 34 % less than in the neat polymer. Transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) results show that most of the montmorillonite particles are well-dispersed and randomly exfoliated in the polymer matrix. A fit of theoretical models to the permeation data estimates that montmorillonite platelets are mostly exfoliated in the polymer matrix and oriented randomly, which matches with results from WAXS and TEM.     

Remote sensing of aquatic vegetation distribution in Taihu Lake using an improved classification tree with modified thresholds

Classification trees (CT) have been used successfully in the past to classify aquatic vegetation from spectral indices (SI) obtained from remotely-sensed images. However, applying CT models developed for certain image dates to other time periods within the same year or among different years can reduce the classification accuracy. In this study, we developed CT models with modified thresholds using extreme SI values (CT(m)) to improve the stability of the models when applying them to different time periods. A total of 903 ground-truth samples were obtained in September of 2009 and 2010 and classified as emergent, floating-leaf, or submerged vegetation or other cover types. Classification trees were developed for 2009 (Model-09) and 2010 (Model-10) using field samples and a combination of two images from winter and summer. Overall accuracies of these models were 92.8% and 94.9%, respectively, which confirmed the ability of CT analysis to map aquatic vegetation in Taihu Lake. However, Model-10 had only 58.9-71.6% classification accuracy and 31.1-58.3% agreement (i.e., pixels classified the same in the two maps) for aquatic vegetation when it was applied to image pairs from both a different time period in 2010 and a similar time period in 2009. We developed a method to estimate the effects of extrinsic (EF) and intrinsic (IF) factors on model uncertainty using Modis images. Results indicated that 71.1% of the instability in classification between time periods was due to EF, which might include changes in atmospheric conditions, sun-view angle and water quality. The remainder was due to IF, such as phenological and growth status differences between time periods. The modified version of Model-10 (i.e. CT(m)) performed better than traditional CT with different image dates. When applied to 2009 images, the CT(m) version of Model-10 had very similar thresholds and performance as Model-09, with overall accuracies of 92.8% and 90.5% for Model-09 and the CT(m) version of Model-10, respectively. CT(m) decreased the variability related to EF and IF and thereby improved the applicability of the models to different time periods. In both practice and theory, our results suggested that CT(m) was more stable than traditional CT models and could be used to map aquatic vegetation in time periods other than the one for which the model was developed.     

生态—水力学法在山区小型引水电站最小下泄流量计算中的应用

以川西某山区小型引水式电站为例,选择水深和流速为生境参数,以华鲮为生态保护目标,计算河道的最小生态需水量和对应的电站最小下泄流量,并与Tennant法、代表年法的计算结果对比。结果表明,生态水深0.12m对应的最小生态流量和Ten nant法的结果差异度为8.63%,较合理;生境参数标准值对计算结果影响显著;在选择合适的参数和参数标准值的前提下,生态—水力学法适用于山区小型河流。     

地方环境保护标准现状分析及“十二五”发展思路

我国地方环境保护标准工作起步晚、发展慢,仍与国家标准存在较大的差距。地方环境保护标准制(修)订的基本思路逐步由传统的保障总量削减目标实现、加严污染排放控制,向改善环境质量、保障环境安全以及实现区域联防联控并重转变。以北京、上海、广东等主要省市地方标准现状为例,分析了地方标准的工作难点,并探讨了"十二五"时期地方标准发展的思路。     

环保修井作业配套技术研究

以吉林油田为例,对油水井修井过程中产生的污染源进行查找分析。针对井下作业工序多,工况复杂的特点,分析了修井作业施工过程的污染源,对污染源采取有效的清洁生产新工艺、新设备,在地面污染防治方面取得了较好的效果。该项技术在减少原油落地损失、降低劳动强度、改善工作环境以及节能等方面取得了较好的经济和社会效益。     

技术减排措施协同控制效应评价研究

随着我国污染减排形势的日益严峻,采用协同控制措施实现多种污染物控制目标逐渐成为一种趋势,而合理评价减排措施的协同效应是正确选择协同控制措施和制定协同控制规划方案的基础.本研究首次从环境-经济-技术角度系统地提出了技术减排措施的协同控制效应评价方法,并以火电行业为案例进行分析.采用协同控制效应坐标系、污染物减排量交叉弹性(Elsa/b)分析和单位污染物减排成本等方法评价技术减排措施对SO2 、NO,和CO2的协同控制效应,三种评价方法相互配合,可以帮助我们从多角度检验不同减排措施的协同效果.对火电行业技术减排措施进行协同控制效应坐标系和污染物减排量交叉弹性分析的结果表明,末端治理措施不具有协同性,而前端控制措施和过程控制措施具有较好的协同性.单位污染物减排成本评价的结果表明,末端治理措施优先度排序靠后,而前端控制措施和过程控制措施排序靠前,且针对不同污染物的排序结果有所不同.在进行协同减排方案设计和规划时,应根据决策需要选择适宜的评价方法,参考评价结果选择最为成本有效的措施.     

基于范例推理的浏阳河隧道风化槽段坍方风险评估

坍方是隧道常见的突发性风险事件.在对已有坍方隧道实例的原因进行了统计分析,并对主要原因进行了力学解释后,进一步应用范例推理方法评估了浏阳河隧道风化槽地段的坍方风险.结果表明:隧道坍方的主要诱因是围岩破碎和降雨,这与断层破碎带处的围岩力学性能差、降水弱化围岩力学性和降低围岩有效应力等有关.浏阳河隧道风化槽地段的范例推理的坍方和梁家山隧道相近,风险为很有可能发生坍方,建议该地段施工中应注重监测信息的反馈并做好超前地质预报.