The pollution halo effect of technology spillover and pollution haven effect of economic growth in agricultural foreign trade: two sides of the same coin?

Environmental Science and Pollution Research - The existing literature on the environmental Kuznets curve (EKC) fails to investigate the spatial attribute of the “pollution halo” effect...     

Effect of pressure and atmosphere during hydrothermal treatment on the properties of sewage sludge-derived solid fuel

Journal of Material Cycles and Waste Management - Efforts to improve the performance of hydrothermal treatment (HT) in producing high-quality solid fuel from sewage sludge were carried out by...     

Methyl methacrylate (MMA) and alumina recovery from waste artificial marble powder pyrolysis

Journal of Material Cycles and Waste Management - Owing to various advantages of artificial marble compared to natural marble, its application has been rising exponentially, which has resulted in...     

How does population structure affect pollutant discharge in China? Evidence from an improved STIRPAT model

Environmental Science and Pollution Research - China is the most populous country in the world, and the pollution caused by the excessive population should not be underestimated. In recent years,...     

Comprehensive utilization of residues of Magnolia officinalis based on fiber characteristics

Journal of Material Cycles and Waste Management - The traditional Chinese medicinal plant Magnolia officinalis has a wide range of applications; including more than 200 kinds of patented Chinese...     

贸易自由化对我国环境的影响——基于ACT模型的实证研究

近年来我国对外贸易发展迅速，但伴随而来的环境污染问题也越来越严重。学术界对我国贸易与环境问题进行了多方面研究，但并未得到一致的结论。文参考ACT模型，试图将贸易自由化对我国环境的影响从经济发展对我国环境的整体效应中分离出来进行研究。本文采用panel数据对我国1992-2004年期间贸易自由化的环境效应进行了实证分析，结果表明：贸易自由化对我国环境消极的规模效应和结构效应远远超过了积极的技术效应，即贸易自由化使我国环境恶化。这主要归因于我国粗放型的经济增长方式以及不完善的环境法规。要改善其不利影响，我国应采用法律和经济措施相结合的办法，从而达到减少贸易的规模效应、改变现有贸易结购以及加强其技术效应的目的。     

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.     

三峡水库忠县至秭归县段消落带植被群落特征研究

为了研究三峡水库周期性的水位调节对消落带植被群落特征的影响，选择重庆忠县至宜昌秭归段的消落带植被群落进行研究，运用重要值和多样性指数分析不同高程的植物种类组成、生活型分布特征及物种多样性。结果表明：（1）研究区域统计植物共32科70属73种，禾本科、菊科和豆科是3个优势科，单种、属现象明显；狗牙根、苍耳、鬼针草、苘麻、鳢肠、酸模叶蓼、莲子草是3个高程的共存种，其中，狗牙根和苍耳在3个高程均为优势物种。（2）研究区域共统计11种植物生活型，在消落带下部和中部，一年生草本植物占绝对优势；在消落带上部，多年生草本植物成为优势生活型，生活型类型多样化，蕨类、藤本、灌木以及乔木植物开始出现。（3）消落带植物群落的丰富度、多样性、均匀度指数均随海拔变化表现出显著差异，并且随海拔升高呈现上升趋势。由此可见，水位变化对植物群落结构和物种多样性产生很大影响，在低海拔区段，消落带物种组成简单化，耐水淹和繁衍能力强的植物成为优势物种；随着海拔上升，水淹胁迫减弱，出现更多适应水位变化的植物种类，使植物群落沿海拔变化形成不同的分布特征。这些研究结果对三峡库区消落带生态修复植物的筛选，以及物种多样性的提高具有参考价值。