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以青海省互助土族自治县为典型研究案例,根据互助县自然条件、地貌类型、资源状况、生态区位、主导生态系统服务功能以及社会经济发展等情况,按照地域连片、主导功能相对一致的原则,对全县进行生态功能区划,在此基础上再进行全县主体功能区划,在研究区域范围4个生态功能区及4个主体功能区合理划分的基础上,提出了促进区域生态建设的对策和建议。研究结果可为构建互助县国土生态安全格局,保护生态环境、促进当地社会经济发展以及生态文明建设提供参考和安全保障。 相似文献
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80年代以业南极上空平流层臭氧层不断减少,1998年9月臭氧洞的面积和深度达历史最高记录。平流层臭氧耗损会导致到达在面地的有害紫外线增加,损害人类的健康和破坏地球生态。介绍了了臭氧层损耗的机理、现状、该领域的研究进展和复旦大学的研究结果。 相似文献
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《环境科学学报(英文版)》2024,36(3):540-552
Surface ozone(O3)is a major air pollutant and draw increasing attention in the Pearl River Delta(PRD),China.Here,we characterize the spatial-temporal variability of ozone based on a dataset obtained from 57 national monitoring sites during 2013-2019.Our results show that:(1)the seasonal difference of ozone distribution in the inland and coastal areas was significant,which was largely affected by the wind pattern reversals related to the East Asian monsoon,and local ozone production and destruction;(2)the daily maximum 8hr average(MDA8 O3)showed an overall upward trend by 1.11 ppbv/year.While the trends in the nine cities varied differently by ranging from-0.12 to 2.51 ppbv/year.The hot spots of ozone were spreading to southwestern areas from the central areas since 2016.And ozone is becoming a year-round air pollution problem with the pollution season extending to winter and spring in PRD region.(3)at the central and southwestern PRD cities,the percentage of exceedance days from the continuous type(defined as ≥3 days)was increasing.Furthermore,the ozone concentration of continuous type was much higher than that of scattered exceedance type(<3 days).In addition,although the occurrence of continuous type starts to decline since 2017,the total number of exceedance days during the continuous type is increasing.These results indicate that it is more difficult to eliminate the continuous exceedance than the scatter pollution days and highlight the great challenge in mitigation of O3 pollution in these cities. 相似文献
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本文通过臭氧对蚕豆急性伤害的研究,描述了蚕豆遭受臭氧急性伤害的反应症状,并阐明蚕豆叶片叶绿素a的变化对蚕豆受害程度的表征作用。 相似文献
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黄磷与氧气在潮湿空气中反应诱发臭氧等活性粒子,可应用于难降解的有机废水处理。实验结果表明,聚乙烯废水、乙醇废水脱色率可达77%-87%。对分散染料废水脱色率仅达26.3%。半黄磷直接投加入聚乙烯废水,乙醛废水诱发反应产生的臭氧等活性粒子通入废水的实验结果表明,以废水体积1L计,投加黄磷5g,脱色反应基本完成,脱色率达80%;CODCr去除量与黄磷投加量成正比。 相似文献
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Yichang Yang Xingang Liu Jun Zheng Qinwen Tan Miao Feng Yu Qu Junling An Nianliang Cheng 《环境科学学报(英文版)》2019,31(5):297-310
A continuous online observation of ozone and its precursors(NOx, VOCs) was carried out in central urban Wuhan from September 2016 to August 2017. The concentration levels of ozone,NOx, VOCs and their variations in urban Wuhan were analyzed, as well as effects of VOCs on ozone photochemical generation and the main controlling factors for ozone production. During the observation period, the average concentrations of ozone and NOx in Wuhan was 22.63 and30.14 ppbv, respectively, and the average concentration of VOCs was 32.61 ppbv(42.3% alkanes,13.0% alkenes, 10.0% aromatics, 7.3% acetylene, 9.9% OVOCs, and 10.5% halohydrocarbons).Ozone concentration was higher in spring and summer as compared with autumn and winter,wheras VOCs and NOx concentratios were lower in spring and summer but higher in autumn and winter. Aromatics and alkenes, two of VOCs species, showed the highest contributions to ozone formation potential in Wuhan(35.7% alkenes, 35.4 aromatics, 17.5% alkanes, 8.6% OVOCs,1.6% halogenated hydrocarbons, and 1.4% acetylene). Among all VOCs species, those with the highest contribution were ethylene, m-xylene, toluene, propylene and o-xylene. The contribution of these five compounds to the total ozone formation potential concentration was 43.90%.Ozone-controlling factors in Wuhan changed within one day; during the early morning hours(6:00–9:00), VOCs/NOx was low, and ozone generation followed a VOCs-limited regime.However, during the peak time of ozone concentration(12:00–16:00), the ratio of VOCs/NOx was relatively high, suggesting that ozone generation followed a NOx-limited regime. 相似文献
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Tropospheric pollutants including surface ozone(O_3), nitrogen dioxide(NO_2), carbon monoxide(CO) and meteorological parameters were measured at a traffic junction(78°2′ E and 27°11′ N) in Agra, India from January 2012 to December 2012. Temporal analysis of pollutants suggests that annual average mixing ratios of tropospheric pollutants were: O_3— 22.97 ± 23.36 ppbV,NO_2— 19.84 ± 16.71 ppb V and CO — 0.91 ± 0.86 ppm V, with seasonal variations of O_3 having maximum mixing ratio during summer season(32.41 ± 19.31 ppbV), whereas lowest was found in post-monsoon season(8.74 ± 3.8 ppbV). O_3 precursors: NO_2 and CO, showed inverse relationship with O_3. Seasonal variation and high O_3 episodes during summer are associated with meteorological parameters such as high solar radiation, atmospheric temperature and transboundary transport. The interdependence of these variables showed a link between the daytime mixing ratios of O_3 with the nighttime level of NO_2. The mixing ratios of CO and NO_2 showed tight correlations, which confirms the influence of vehicular emissions combined with other anthropogenic activities due to office/working hours, shallowing, and widening of boundary layer. FLEXTRA backward trajectories for the O_3 episode days clearly indicate the transport from the NW and W to S/SE and SW direction at Agra in different seasons. 相似文献
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气象干旱是影响人类社会最严重的气象灾害之一,且对中纬度干旱半干旱地区的危害更为显著。为探究气候变化背景下我国甘肃地区干旱事件的时空分布,首先根据甘肃1969—2018年月值气象资料计算标准化降水蒸散指数(SPEI),通过游程理论提取干旱事件。随后采用REOF旋转正交分解将研究区划分成5个气候子区,并以每个子区为单位,基于B-G分割算法细致对比各子区不同时间尺度干旱事件的变化特征和演变趋势。最后,采用相关性分析探究各子区干旱事件的驱动因素。主要结论有:(1)研究区干旱累积历时呈微弱增加趋势(0.475 d·(10a)−1)并存在19 a的主周期,干旱强度呈先缓和再加剧趋势,尤其是2000年后干旱加剧显著,并呈现出西北部干旱减轻、东南部干旱加剧的空间变化趋势。(2)REOF分解的前五个模态累积贡献率为53.06%,主要的空间分布模态为:全区一致型模态和南北反向分异模态。将研究区分为5个干旱子区:河西地区、河东中部地区、河东东部地区、乌鞘岭地区和河东西部地区。(3)河西地区自1988年以来气象干旱显著缓和(P<0.01);河东东、中、西部地区存在不同程度的干旱加剧趋势(0.120·(10a)−1、0.129·(10a)−1、0.072·(10a)−1,P>0.05);乌鞘岭地区在1975年以后气象干旱显著缓和(P<0.01),形成了干旱缓和与加剧变化的分水岭区域。(4)季节上,河西地区仅夏季呈缓和趋势;河东东部地区春季呈显著干旱化趋势,而秋季相反;河东西部地区春夏两季气候干旱化趋势明显而秋冬两季相反;河东中部地区和乌鞘岭地区季节变化呈明显一致性,前者四季均呈干旱化趋势,且春季干旱化最剧烈,后者四季均呈缓和趋势,且冬季最明显。(5)研究区气象干旱受当地气候因子和环流因子因素的共同影响,河西地区和河东西部地区对气温的响应明显而河东中、东部地区则对降水量的响应明显;乌鞘岭地区对日照时数的响应明显;NAO指数对研究区夏季气象干旱存在重要影响而ENSO事件(厄尔尼诺-南方涛动)对研究区春秋两季(尤其是春季)气象干旱存在重要影响。 相似文献
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超声-臭氧氧化处理硝基苯废水实验研究 总被引:12,自引:0,他引:12
在实验装置上对超声-臭氧氧化处理硝基苯废水进行了实验研究,主要考察了废水初始pH值、反应时间,臭氧通入量、超声功率等因素对硝基苯去除率的影响,实验结果表明,超声辐射可以在臭氧氧化过程中起加速反应的作用,而且随着超声功率的增大,加速反应的能力增强;废水初始pH值为11时硝基苯去除效果最佳;随着臭氧通入量的增大,反应时间的延长,硝基苯去除率不断增大;超声-臭氧处理硝基苯废水过程中硝基苯的降解规律为表现一级反应。 相似文献
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对沈阳市区环境空气中的臭氧污染现状进行了调查与分析,利用沈阳市大气自动监测系统的数据,分别分析了沈阳城市中心区和城市边缘区臭氧的污染情况以及臭氧与其他污染物之间的相关性,并总结了臭氧与其他污染物的季节性变化趋势。 相似文献
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探讨了Pb、Pb-0.5%Sn、Pb-0.8%Sn、Pb-1.78%Sn、Pb-1.35%Sn-0.049?、Pb-0.8%Sn-0.1%Ca-0.1%Ce铅合金电极的电化学性能、耐腐蚀性能和电解产生臭氧的产率,及铅合金电极在不同电流强度条件下电解产生臭氧的最佳条件。实验结果表明:掺杂了Sn,Ce等金属能提高铅合金电极的析氧电位和臭氧产率,其中当以PB-0.8%Sn-0.1%Ca-0.1%Ce合金电极为阳极,铂电极为阴极。饱和硫酸钾溶液为电解液,电流强度为7.5mA时,臭氧产率最高达到19%。 相似文献
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有机废水湿式O3氧化降解过程的研究 总被引:9,自引:1,他引:9
采用 O3 湿式氧化降解含氯乙烯的有机废水 ,实验研究了不同 p H、不同温度以及不同初始氯乙烯浓度对反应过程的影响 ,初步探讨了在高 p H时 O3 的自分解催化产生自由基 OH·机理和污染物的氧化降解过程。通过实验研究与分析 ,获得了氯乙烯有机废水 O3 氧化过程的动力学方程 相似文献
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Ozone (O3) concentration and flux (Fo) were measured using the eddy covariance technique over a wheat field in the Northwest-Shandong Plain of China. The O3-induced wheat yield loss was estimated by utilizing O3 exposure-response models. The results showed that: (1) During the growing season (7 March to 7 June, 2012), the minimum (16.1 ppbV) and maximum (53.3 ppbV) mean O3 concentrations occurred at approximately 6:30 and 16:00, respectively. The mean and maximum of all measured O3 concentrations were 31.3 and 128.4 ppbV, respectively. The variation of O3 concentration was mainly affected by solar radiation and temperature. (2) The mean diurnal variation of deposition velocity (Vd) can be divided into four phases, and the maximum occurred at noon (12:00). Averaged Vd during daytime (6:00–18:00) and nighttime (18:00–6:00) were 0.42 and 0.14 cm/sec, respectively. The maximum of measured Vd was about 1.5 cm/sec. The magnitude of Vd was influenced by the wheat growing stage, and its variation was significantly correlated with both global radiation and friction velocity. (3) The maximum mean Fo appeared at 14:00, and the maximum measured Fo was − 33.5 nmol/(m2·sec). Averaged Fo during daytime and nighttime were − 6.9 and − 1.5 nmol/(m2·sec), respectively. (4) Using O3 exposure-response functions obtained from the USA, Europe, and China, the O3-induced wheat yield reduction in the district was estimated as 12.9% on average (5.5%–23.3%). Large uncertainties were related to the statistical methods and environmental conditions involved in deriving the exposure-response functions. 相似文献
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Bing Feng Chunbo Wang Xingqiang Wu Cuicui Tian Meng Zhang Yingying Tian Bangding Xiao 《环境科学学报(英文版)》2019,31(10):184-196
Lake Caohai has experienced extensive Microcystis blooms in recent years,and to improve its water quality,the local government carried out a series of water control measures.To better understand the dynamics of both pelagic and benthic Microcystis and their characteristics in Lake Caohai,we conducted a 1-year investigation from December 2015to December 2016 to gain a seasonal outlook on the distribution and dynamics of cell abundance,colony size and intracellular microcystins(MCs)of Microcystis.The results indicated that the Microcystis bloom occupied primarily the northeastern region and then moved gradually from lakeshore to lake center.The perennial southwesterly winds and the water inflow from northeast to southwest in Lake Caohai determined the spatiotemporal distribution of pelagic Microcystis.Benthic Microcystis was mainly distributed in the northeastern region in summer,occupied the lake center in autumn and then occupied the southeastern region in winter,determined by the sedimentation of pelagic Microcystis and the death of benthic Microcystis.Small colonies(20-60μm)overwintered more easily in both water column and sediment.The concentrations of intracellular toxin of benthic Microcystis were observed to be significantly higher than those of pelagic Microcystis.This might be because Microcystis synthesized large amount of MCs to acclimate to an unfavorable benthic environment.This knowledge on the dynamics of Microcystis expands our understanding of mechanisms underpinning the formation of Microcystis blooms. 相似文献