Simultaneous removal of cyanobacterial blooms and production of clean water by coupling flocculation with a rotary drum filter

Environmental Science and Pollution Research - A mechanical harvesting technology based on coupling flocculation with a rotary drum filter (RDF, 35-μm) was applied to remove cyanobacterial...     

基于关联性及趋势性分析的AVHRR NDVI及#br# MODIS NDVI数据产品比较

针对AVHRR NDVI和MODIS NDVI数据集中不同数据产品间的差异和区域适应性问题，利用2003~2013年重叠时间段MODIS Terra/Aqua的NDVI Collection 5(C5)和Collection 6(C6)产品以及AVHRR NDVI中的GIMMS NDVI3g产品，选择汉江流域典型区域进行数据对比分析。通过关联指数IOAs(Index of Association)来评价各数据在季节波动上的一致性；采用Mann Kendall检验分析各数据的长期趋势差异。结果表明，在季节性变化上，同一卫星不同版本产品之间的关联性相对较高。在年际变化上，GIMMS产品相对MODIS 产品，仅能检出部分NDVI变化趋势。在地表覆被异质性相对较高地区，GIMMS产品的长期变化趋势检出率较低。MODIS Terra的NDVI C5产品受传感器退化影响，表现出相对较高的减少趋势。 关键词： GIMMS NDVI；MODIS NDVI；Mann Kendall检验；趋势分析     

Processes involved in uptake and release of nitrogen dioxide from soil and building stones into the atmosphere

Atmospheric NO₂ was taken up by samples of various soils and building stones. The NO₂ uptake rate constants were highest in soil samples taken during the summer months. However, the NO₂ uptake rate constants of the soils and building stones were not significantly correlated with any of the following variables: moisture, pH, ammonium, nitrite, or nitrate. NO₂ uptake by soil and stone was not abolished by autoclaving indicating a chemical uptake process. NO₂ uptake by acidic and air-dry soils and stones resulted in nearly stoichiometric reduction of NO₂ to NO. This reduction was enhanced by the addition of ferrous iron and was further enhanced by incubation under 1 ppmv SO₂. The results suggest that NO₂ reduction may be coupled to oxidation of ferrous to ferric iron which may be reduced again by atmospheric SO₂ thus regenerating the ferrous iron content of the soil or stone. Conversion of NO₂ to NO was not observed in neutral or/and moist soils and stones. NO₂ was also taken up by purified and sterilized quartz sand moistend with water. This uptake was enhanced by addition of humic material but not by addition of bacteria which both had been extracted from genuine soil. Under most conditions, only uptake but no release of NO₂ was observed. However, NO₂ was released in air-dry soils that were heated to 45–65°C, or in ammonium-fertilized soil or stone that was drying up at room temperature. Under the latter conditions mimicking field practice, the NO₂ release reached rates that were similar to the NO release rates.     

深冲钢板塑性变形形为研究

单相塑性材料的强度和塑性基本上是分别研究讨论的。此文以低碳深冲钢板为例,从能量观点出发,讨论了强度和塑性的内在制约关系,唯象地提出了单相塑性材料塑性破坏的判据,并解释了几个实验现象。此文的研究有助于加深对深冲钢塑性变形形为的理解。     

乡镇工业污染防治战略初探

本文通过对乡镇工业经济发展现状及其环境问题的评价分析,提出乡镇工业环境管理应按本地自然条件、经济发展水平和乡镇企业的特点,实施分区域、按行业、有重点地进行管理的防治战略。并建议我国环境管理在以城市和大工业为重点的同时,及早将乡镇工业污染防治工作放在战略高度加以重视,切实加强乡镇工业环境管理。     

劳动保护工作的价值

在市场经济条件下,事物本身的价值决定着它的社会地位。劳动保护工作也同其他事物一样,在生产经营活动中的地位由其本身的价值决定劳动保护工作到底有多大价值?目前尚无理论根据。由于没有价值指标,在以经济效益为中心的生产经营活动中,它的地位就时而重要时而不重要。出事故的时候就重要,不出事故时就不重要。一些企业或基层领导人重生产轻劳动保护,他们认为:生产效益不好,劳动保护再好也没用;劳动保护本身没有效益,效益是间接的;劳动安全是个负效益,只是发生事故造成损失,才能看出“安全效益”。     

β修正罗丹明B光度法测定工业废水中银

对β修正光度法测定废水中痕量银进行了研究，该方法能消除反应液中过量显色剂干扰，提高分析灵敏度和准确度。测定结果表明，银加标回收率９３．０－１０６．０％，精密度ＲＳＤ２．３％，银量低测定浓度０．０２ｍｇ／Ｌ。该方法适合于印相，电镀等行业废水银分析。