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711.
传统水质监测方法耗时且费力,而基于高光谱的水质监测技术可实现对水质的快速、直观、原位监测。以扬州古运河三湾段为研究区域,基于无人机高光谱成像仪与水质走航监测船相配合,采用空地协同模式和偏最小二乘回归算法对总磷(TP)、总氮(TN)、氨氮(NH3-N)、高锰酸盐指数(IMn)4个水质参数进行定量反演研究。结果表明:该反演模型的决定系数(R2)为91%~97%;拟合效果依次为NH3-N>IMn>TN>TP;各指标反演误差绝对值为0.2%~4%。该方法具有较好的反演效果,可快速、准确地获取城市河道水质分布情况,适用于城市水环境监测。 相似文献
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介绍淮南矿业集团近年来创建环境友好企业的基本做法,通过在积极推进市矿统筹,建设生态和谐矿区;构建循环经济产业链,促进资源综合利用;强化环保全过程管理,落实污染防治及减排等方面的有效工作,促进了经济建设与区域环境协调发展。 相似文献
714.
Recent advances in ultrasound and molecular genetics have increased our understanding and hence enhanced the perinatal management of complete and partial hydatidiform mole. By contrast, the management of a twin pregnancy combining a normal pregnancy with a normal fetus and a complete hydatidiform mole (CHM) remains complex and controversial due to conflicting data from different parts of the world. The aim of this review is to analyse the international literature on twin pregnancies that include a mole, present the complications and outcome of pregnancy and to discuss the perinatal management. Management is complicated and women should be counselled about the maternal and fetal complications, and the pregnancy monitored carefully by a perinatal team with experience in high-risk obstetrics and access to neonatal care. The data reviewed here suggest that a woman who decides to continue with the pregnancy including a CHM must be aware that, overall, she only has a one in four chance of live birth and in around 35% of cases she will develop persistent trophoblastic disease (PTD) after delivery. In ongoing pregnancies, there will be, in at least 20% of the cases, an early onset of pre-eclampsia (PET) and a 29% risk of fetal loss due to late miscarriage, intrauterine death and neonatal death. Maternal serum human chorionic gonadotrophin (MShCG) could be useful in predicting outcome in twin pregnancy combining normal pregnancy and CHM, but this needs to be investigated prospectively. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
715.
韩凌 《中国人口.资源与环境》2008,18(4)
由于废物和副产品成为主要生产原料,产业生态系统在规模经济性方面表现出了与传统产业系统的不同。本文分析了影响产业生态系统规模经济性的5大因素:废料作为原材料的主要来源;以可更新能源替代化石能源;经济活动主体之间大量的物质交流;与周围环境在物质输入输出上保持平衡;信息不对称明显阻碍废物和回收市场的动作。这些因素导致了产业生态系统与传统产业系统在边际成本上的差异,即边际成本并不是随着规模的增加而降低的。论文指出,产业生态系统具有适度规模经济特征,在生产聚焦和生活聚居上表现出小规模化的趋势,表现为相对较小的空间分布和相对局限的生产规模。这样的规模对于处理分散的、高熵值的资源和能源与集约化生产和消费模式之间的矛盾有相当的灵活性。论文最后对进一步开展研究的方向和内容提出了建议。 相似文献
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Fluroxypyr (4-amino-3,5-dichloro-6-fluoro-2-pyridinyl-1-methylheptyl ester) is a widely used herbicide for controlling weeds, fungi, and insects. However, extensive use of the herbicide has led to its high accumulation in ecosystems and contamination to soils and crops. Environmental behaviors and fate of herbicides are dependent on many physiochemical and biological factors. Whether fluroxypyr is significantly affected and how it is degraded under the environmental conditions is largely unknown. The present study investigated the effects of soil microbe, soil type, dissolved organic matter (DOM), temperature, soil moisture, and surfactant on fluroxypyr degradation in soils. Application of DOM derived from sludge and straw to fluroxypyr-contaminated soils increased degradation of fluroxypyr. Environmental factors such as temperature, moisture, soil microbe and soil type could affect the rate of fluroxypyr dissipation. Also, the microorganism affected the degradation of fluroxypyr. Analysis by gas chromatography-mass revealed that the reaction in soils might include the removal of 1-methylheptyl ester to generate fluroxypyr acid (4-amino-3,5-dichloro-6-fluoro-2-pyridiny). Our results provided initial data that a set of biological and physiochemical factors coordinately regulates the decay of fluroxypyr in soils. 相似文献
719.
Ling Zhang Zengwei Yuan Jun Bi Bing Zhang Beibei Liu 《Journal of Cleaner Production》2010,18(5):504-509
China has rapidly developed a number of Eco-industrial parks (EIPs) in recent years. In order to promote and regulate their development, two government agencies, the Ministry of Environmental Protection and the National Development and Reform Commission are currently engaged in promoting national pilot EIP programs. Both agencies have developed their own management systems, and 60 industrial parks have been approved for construction of national pilot EIPs, among which six parks appear in both lists of the two agencies. This article introduces the practice of the national pilot EIPs. It first describes the management systems and achievements within the two programs, and then summarizes the problems encountered thus far in program implementation. Finally it proposes brief suggestions for future development of EIPs. 相似文献
720.
复合垂直流人工湿地氧化还原特征及不同功能区净化作用研究 总被引:1,自引:0,他引:1
研究了复合垂直流人工湿地系统氧化还原电位(Eh)的时空变化规律及不同功能区中污染物的净化效果。结果表明:湿地系统下行流池表层、两池底层、上行流池表层Eh的变化范围分别为402~585、-87~-130、308~432 mV,沿水流方向依次形成了好氧A区/缺氧、厌氧区/好氧B区3个功能区。好氧A区是污染物去除的主要区域,BOD5、CODCr、NH+4- N的去除率分别为430%、484%、541%,特别是NH+4 N去除率占总去除率的79%;缺氧、厌氧区主要是进行反硝化反应和有机物的厌氧分解;好氧B区则主要是去除厌氧分解后的有机物以及进一步脱氮。另外,NH+4 N的去除率与系统各功能区Eh呈显著相关关系(〖WTBX〗p〖WTBZ〗<001),而BOD5、CODCr、NO-3-N的去除率与系统各功能区Eh相关性不显著。 相似文献