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Cai W.,Key Laboratory of Urban Agriculture South | Liu R.,Shanghai JiaoTong University

A commercial-scale biomass fast pyrolysis plant, based on downdraft circulating fluidized bed technology with biomass throughput of 1-3 T h-1, has been developed for bio-oil production and its performance has been investigated. The technological process consists of six parts: a feeding system, a heat carrier system, a reactor system, a cyclone system, a condensation system and a carbon separating system. The plant has four circulation systems: circulation of a heat carrier, quenching materials (bio-oil), cooling water and non-condensable gas. The bio-oil, raw material (rice husks), char and non-condensable gas samples were analyzed using GC-MS, FTIR, and SEM to characterize the physical properties and chemical composition. Results showed that the operation of the plant was stable. At 550 °C, the highest yield of bio-oil obtained was 48.1 wt% with char, and non-condensable gas yields of 26.0 wt% and 25.9 wt%, respectively. GC-MS results revealed that the composition of the bio-oil was complicated and the most abundant compound category was phenolics (14.92%). The char had complex pore structure by SEM analysis, which can be collected as a resources for further comprehensive utilization. © 2016 Elsevier Ltd. Source

Gao Y.,Shanghai JiaoTong University | Gao Y.,Key Laboratory of Urban Agriculture South | Ma Y.,Agricultural Committee of Chongming County
Habitat International

Rapid urbanization has generated an excessive demand for land in suburban China, while the supply is limited. Concurrently, prevalent land idleness in rural areas has received little political and academic attention. Drawing on evidence from suburbs of Shanghai, this paper examines the monitoring of idle rural industrial land. We argue that idle rural industrial land is absent from the current monitoring, and that the ambiguous collective ownership in rural China has not only prevented effective management of idle land, but also imposed the greatest obstacle to the redevelopment of these idle sites. Hence, the clarification of collective ownership will help to achieve more efficient use of rural land in suburban China. © 2015 Elsevier Ltd. Source

Kang H.,Shanghai JiaoTong University | Zhuang H.,Shanghai JiaoTong University | Wu L.,Shanghai JiaoTong University | Liu Q.,Shanghai JiaoTong University | And 5 more authors.
Forest Ecology and Management

Nitrogen (N) and phosphorus (P) and N:P ratio in terrestrial plants and the patterns at a large geographical scale are an important issue in ecological stoichiometry. In particular, it is essential to know that for a single species, how the N:P stoichiometry varies with climatic factors in the context of global warming. Our analysis was based on a data set including 2583 observations at 441 sites on nutritional status of Norway spruce (Picea abies L.) located in European counties (including Austria, Belgium, Bulgaria, Czech Rep., Finland, Germany, Ireland, Italy, Lithuania, Norway, Slovak Rep., Slovenia, United Kingdom). Our objectives are to demonstrate how leaf N and P concentration and N:P ratio in Norway spruce vary with altitude (ALT), latitude (LAT), longitude (LON), mean annual temperature (MAT) and mean annual precipitation (MAP) across Europe. The results showed that for 1-year-old needles of Norway spruce, the N and P concentration were 13.28mgg-1, 1.41mgg-1 and the N:P ratio was 9.76. Leaf N displayed a convex curve pattern with increasing MAT and decreasing LAT from the boreal Europe to the Mediterranean area. The N concentration and N:P generally reached peak at about 7°C in MAT or 53° N in LAT. The N:P ratio varied non-linearly with LAT and MAP, but linearly with MAT. Leaf N concentration and N:P ratio decreased linearly with increasing ALT in temperate European area. Across Europe, that the patterns of leaf N and N:P ratio were mainly driven by climate-related geochemistry and plant physiology, but also greatly impacted by anthropogenic N deposition. © 2010 Elsevier B.V. Source

Zhou P.,Shanghai JiaoTong University | Yang F.,Shanghai JiaoTong University | Ren X.,Shanghai JiaoTong University | Huang B.,Rutgers University | And 2 more authors.
Environmental and Experimental Botany

Aluminum (Al) toxicity in acid soils is a major constraint on crop production. The objective of this study of alfalfa (Medicago sativa L.) was to determine whether Al-induced inhibition of root growth in alfalfa (M. sativa L.) is related to Al distribution in different root tissues, changes in endogenous level of indole-3-acetic acid (IAA) in root tips, and the expression of key genes in IAA metabolism and translocation. Roots of alfalfa were exposed to 100μM Al3+ in half-strength Hoagland's nutrient solution. The inhibitory effects of Al on root elongation was more pronounced than on root and shoot biomass accumulation. Lumogallion, an Al specific stain, was used to monitor tissue locations of Al in the root. Lumogallion-Al was mainly detected in the root cap, epidermis, and stele of Al-treated roots. In the meristematic region of the root tip, Al accumulated mainly in the cell wall, intracellular membrane system and center of the nucleus. The similar distribution of Al ions in the root with that of auxin revealed that Al in roots may affect IAA levels. High performance liquid chromatography analysis demonstrated that IAA levels increased in the base of the root and decreased in the root tips treated with 100μM Al3+ for 3d compared to that of the control (without Al). Reverse transcription and quantitative PCR showed that the expressions of three genes, auxin transporter-like protein, auxin efflux carrier component, and cationic peroxidase, were significantly higher in Al-stressed alfalfa roots than in the control while the expression of auxin conjugate hydrolase was significantly lower. These results suggested that Al-inhibition of root elongation could be associated with Al accumulation in apoplast and membrane system, and alteration of IAA transport in the root. © 2014 Elsevier B.V. Source

An Y.,Shanghai JiaoTong University | An Y.,Key Laboratory of Urban Agriculture South | Zhou P.,Shanghai JiaoTong University | Xiao Q.,Inner Mongolia Academy of Agricultural and Animal Husbandry science | Shi D.,Heze University
Journal of Plant Nutrition and Soil Science

Organic acids (OA) may affect plant resistance to aluminum (Al) toxicity in acidic soils. However, limited information is available on the effects of different organic acids on Al resistance in alfalfa. We investigated the effects of foliar application of organic acids (succinic acid, citric acid, malic acid, and oxalic acid) to alfalfa (Medicago sativa L.) under Al stress. Seedlings were grown in pH 4.5 nutrient solution containing Al at 0 or 100 μM, and were sprayed with water or 100 μM of oxalic acid, malic acid, citric acid, or succinic acid every 3 d during a 10 d experiment. Aluminum stress caused significant reduction in alfalfa growth (reflected by above-ground biomass, root weight and root length), root activity, mineral nutrient concentrations (Ca, K, Mg, Mn and Zn), and a significant increase in leaf membrane lipid peroxidation. Foliar application of the four organic acids, especially succinic acid, alleviated Al toxicity, as demonstrated by the increase in plant growth and root activity, as well as reduction in lipid peroxidation. Oxalic acid and malic acid treatments significantly increased oxalate exudation and decreased Al concentration in roots exposed to Al stress. Succinic acid treatment significantly increased accumulation of all four organic acids in roots, accumulation of Ca, K, Mg, Mn and Zn, and up-regulated the gene transcription of malate dehydrogenase (MDH) and phosphoenolpyruvate carboxylase (PEPC) in roots. Our results suggest that the promotion of oxalate exudation from roots through exogenous application of oxalate and malate could contribute to the improvement in Al resistance of alfalfa, and the positive effects of exogenous application of succinate on Al resistance may be associated with the increased endogenous accumulation of all four organic acids in roots, which may constitute an organic-acid detoxification system in alfalfa. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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