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181.
环境应急预案体系建设在落实"一案三制"中具有重要作用。本文通过总结广东省突发环境事件应急预案体系的建设情况,梳理分析政府及企业突发环境事件应急预案在工作实践过程中遇到的问题,从顶层设计、功能定位、编制方法、改进机制等方面提出意见和建议,进一步健全环境应急管理体系。 相似文献
182.
A MnOx–NbOx–CeO2 catalyst for low temperature selective catalytic reduction(SCR) of NOx with NH3 was prepared by a sol–gel method, and characterized by NH3–NO/NO2 SCR catalytic activity, NO/NH3 oxidation activity, NOx/NH3 TPD, XRD, BET, H2-TPR and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy(DRIFTS). The results indicate that the Mn Ox–Nb Ox–CeO2 catalyst shows excellent low temperature NH3-SCR activity in the temperature range of 150–300℃. Water vapor inhibits the low temperature activity of the catalyst in standard SCR due to the inhibition of NOx adsorption. As the NO2 content increases in the feed, water vapor does not affect the activity in NO2 SCR. Meanwhile, water vapor significantly enhances the N2 selectivity of the fresh and the aged catalysts due to its inhibition of the decomposition of NH4NO3 into N2O. 相似文献
183.
184.
基于对江苏省太湖流域农村生活污水处理设施的全面调研,统计分析了江苏省太湖流域农村生活污水处理设施现状,包括建设数量、建设规模、处理工艺、运维模式、经费来源等,探讨了江苏省太湖流域农村生活污水处理设施存在的问题并提出建议。结果表明:目前江苏省太湖流域农村生活污水处理设施以中小规模(<100 t/d)为主,主要采用生物生态耦合处理技术,出水一般执行(GB 18918-2002)《城镇污水处理厂污染物排放标准》中的一级B标准,以属地管理的运维模式为主。应加快制订符合江苏省太湖流域的农村生活污水处理设施建设标准,并形成责任主体明确、监管制度完善、资金投入有保障的长效稳定运行体制。 相似文献
185.
液中膜MBR工艺是将膜分离技术与传统生化处理技术相结合的一种新型、高效的污水处理方法,具有出水水质好、设备占地面积小、活性污泥浓度高、剩余污泥量少等特点。采用该工艺对生活污水处理进行了工程应用,对工程设计运行参数和污染物去除机制进行研究,并进行技术经济分析。结果表明:出水COD、氨氮、SS等指标均优于GB/T18920—2002《城市污水再生利用——城市杂用水水质》要求,出水可回用于浇洒道路、绿化、冲厕等,并提出根据出水氨氮浓度的变化作为系统排泥的依据,有效地指导工程的稳定运行。 相似文献
186.
以河源市区2016年3月27日—4月4日污染过程为研究对象,基于同期气象条件与空气质量监测数据,分析了PM_(2.5)与气象因子间的相关性,探究河源市区PM_(2.5)污染变化特征。结果表明,3月30日河源市ρ(PM_(2.5))/ρ(PM_(10))和ρ(PM_(2.5))/ρ(CO)分别为0.87和0.08,明显高于其他时段,说明当天细颗粒物污染老化和二次转化程度突出。在此次污染过程的2个不同阶段,河源市ρ(PM_(2.5))波动受到多项气象要素共同影响,其中与气压先后呈现较强负相关(R~2=0.646 2)和不明显正相关(R~2=0.006 5),与气温呈现不明显正相关(R~2=0.008 4,R~2=0.033 9),与风速先后呈现弱负相关(R~2=0.105 2)和不明显正相关(R~2=0.072 9),与相对湿度先后呈现弱正相关(R~2=0.391 3)和弱负相关(R~2=0.176 9)。通过比较该时段河源市与周边城市的ρ(PM_(2.5))变化趋势及后向轨迹分析,发现河源市与周边城市在相似的气象背景条件下,PM_(2.5)污染主要来源于本地源排放和珠三角区域传输。 相似文献
187.
过氧化氢(H_2O_2)和一氧化氮(NO)作为信号分子,可调节植物生长、发育以及应对外源性胁迫。利用过氧化氢酶(CAT)以及NO清除剂(PTIO),研究了除草剂阿特拉津(atrazine,100μg·L~(-1))影响小球藻生长的机理,并分析内源性H_2O_2和NO在小球藻抗除草剂胁迫中的作用。研究结果表明,阿特拉津在诱发小球藻细胞死亡的过程中,不同程度促发了H_2O_2和NO生成;外源CAT可通过清除H_2O_2和诱导NO来缓解阿特拉津对小球藻的生长抑制;PTIO与阿特拉津的联合实验进一步证实,小球藻体内的NO诱导与H_2O_2的爆发无关,它们之间的合成没有相关性。因此,除草剂阿特拉津主要通过诱导小球藻体内的H_2O_2爆发来破坏藻细胞,抑制其生长,与NO的信号传递无关。 相似文献
188.
Like many other benthic infaunal invertebrates, spionid polychaetes often lose portions of their bodies to predators, which
affects their activities. Feeding palp loss and tail loss have been studied in several spionids, but the capacity for anterior
tissue regeneration has not been compared in different species. The present study examines anterior tissue regeneration in
two species, Dipolydora quadrilobata (Jacobi 1883) and Pygospio elegans Claparède 1863, in two laboratory experiments. Tissue removal treatments included removal of palps only, removal of anterior
tissue through the first setiger, anterior tissue through the fifth setiger, all anterior tissue through half of the gill-bearing
setigers, and all anterior tissue through the last gill-bearing setiger. Regeneration was monitored by capturing images of
the worms and digitizing the area of regenerated anterior tissue or counting the number of segments that grew over time. Worms
of both species regenerated anterior tissue regardless of the amount removed. Morphogenesis during regeneration followed a
similar pattern in these two species regardless of the amount of anterior tissue lost, progressing from wound healing to formation
of a recognizable prostomium and peristomium (“head”) by 6 days post-ablation. Palp and setal growth, addition of segments,
and formation of nuchal organs and the ciliated food groove followed so that worms appeared to have re-grown “normal,” but
smaller, “heads” and palps by 9–12 days following ablation. Over the course of 16 days, worms that lost more segments regenerated
less tissue relative to their initial intact size and did so more slowly. There was no significant palp growth during the
first 3 days following ablation. Rate of segment addition was directly related to the degree of tissue loss in D. quadrilobata. P. elegans added segments at similar rates whether 50 or 70% of the original segments was removed. 相似文献
189.
Learning,retention and coding of nest-associated visual cues by the Australian desert ant, <Emphasis Type="Italic">Melophorus bagoti</Emphasis> 总被引:3,自引:0,他引:3
Ajay Narendra Aung Si Danielle Sulikowski Ken Cheng 《Behavioral ecology and sociobiology》2007,61(10):1543-1553
A variety of social insects use visual cues for homing. In this study, we examine the possible factors affecting the learning
and retention of nest-associated visual cues by the Australian desert ant Melophorus bagoti and the manner in which such cues are encoded by foraging ants. We placed four prominent cylindrical landmarks around a nest
and trained foragers from that nest to a food source. Ants were tested with the landmark array in a distant testing field
after (1) a known number of exposures to the landmarks (1, 3, 7 or 15 trials, spread over a period of 1 day, 2 days or ≥3 days)
and (2) after a known period of delay (0, 24, 48, 96 or 192 h). The results show that a combination of an increase in training
trials and an increase in number of training days affected the acquisition of landmark memory. Moreover, once the landmarks
were learnt, they became a part of long-term memory and lasted throughout the ants’ foraging lifetime. To examine visual cue
encoding behaviour, ants trained under similar conditions for 4 days were tested with (1) an identical landmark array, (2)
landmarks of the same size used in training, but placed at twice the distance from each other, and (3) landmarks whose dimensions
were doubled and placed at twice the distance from each other. In conditions (1) and (3), the ants searched extensively at
the centre of the four landmarks, suggesting that, similar to the Saharan ant (genus Cataglyphis) and the honeybee, M. bagoti too uses a snapshot to match the view of the landmarks around the nest. But contrary to the snapshot model, in condition
(2), the ants did not search extensively at the centre of the landmarks, but searched primarily 0.5 m from the landmark, the
distance from each landmark to the nest during training. We discuss how various search models fare in accounting for these
findings. 相似文献
190.
罗得河积水区地表径流中铝形态的变化 总被引:1,自引:0,他引:1
美国东部地区的罗得河流域遭受严重的酸沉降侵蚀,对流域和内湖生态系统产生致毒影响。监测地表水和土壤水中的铝形态及浓度变化是问题关键。该文应用自行设计的改进MINQL微机模型对该地区地表径流中铝 动力学变化规律了分析,得出有价值的论述。 相似文献