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Long-term effects of environmentally relevant concentrations of silver nanoparticles on microbial biomass, enzyme activity,and functional genes involved in the nitrogen cycle of loamy soil 被引量:9
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作者 Anna-Lena Grün Susanne Straskraba +2 位作者 Stefanie Schulz Michael Schloter Christoph Emmerling 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第7期12-22,共11页
The increasing production and use of engineered silver nanoparticles(AgNP) in industry and private households are leading to increased concentrations of AgNP in the environment. An ecological risk assessment of AgNP... The increasing production and use of engineered silver nanoparticles(AgNP) in industry and private households are leading to increased concentrations of AgNP in the environment. An ecological risk assessment of AgNP is needed, but it requires understanding the long term effects of environmentally relevant concentrations of AgNP on the soil microbiome. Hence, the aim of this study was to reveal the long-term effects of AgNP on soil microorganisms. The study was conducted as a laboratory incubation experiment over a period of one year using a loamy soil and AgNP concentrations ranging from 0.01 to 1 mg AgNP/kg soil. The short term effects of AgNP were, in general, limited.However, after one year of exposure to 0.01 mg AgNP/kg, there were significant negative effects on soil microbial biomass(quantified by extractable DNA; p = 0.000) and bacterial ammonia oxidizers(quantified by amo A gene copy numbers; p = 0.009). Furthermore, the tested AgNP concentrations significantly decreased the soil microbial biomass, the leucine aminopeptidase activity(quantified by substrate turnover; p = 0.014), and the abundance of nitrogen fixing microorganisms(quantified by nif H gene copy numbers; p = 0.001). The results of the positive control with Ag NO3 revealed predominantly stronger effects due to Ag+ion release. Thus, the increasing toxicity of AgNP during the test period may reflect the long-term release of Ag^+ions. Nevertheless, even very low concentrations of AgNP caused disadvantages for the microbial soil community, especially for nitrogen cycling, and our results confirmed the risks of releasing AgNP into the environment. 展开更多
关键词 Silver nanoparticles SOIL Microbiome AMOA NIFH Leucine aminopeptidase activity AgPure
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Effect of environmental enrichment on the body shape of the pumpkinseed
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作者 Noelle Fabre Anna Vila-Gispert +1 位作者 Cristina Galobart Dolors Vinyoles 《Current Zoology》 SCIE CAS CSCD 2020年第5期597-599,共3页
How the morphology of captive-reared fish is affected by structural enrichment in their rearing tanks is not well understood.Some studies have suggested that deficiencies in rearing environments could produce inapprop... How the morphology of captive-reared fish is affected by structural enrichment in their rearing tanks is not well understood.Some studies have suggested that deficiencies in rearing environments could produce inappropriate body shape in salmonids(Vehanen and Huusko 2011).Garduho-Paz et al.(2010)have found significant differences in body and head shapes of 3-spine stickleback Gasterosteus aculeatus,depending on whether fish were reared in an environment with just gravel or in an environment enriched with large stones and artificial plants. 展开更多
关键词 SHAPE PUMP BODY
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Statistical Approach to Identify Environmental Factors in Controlling Heavy Metal Concentrations in Sediment
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作者 Hassan Alshemmari Eqbal Al-Enezi +1 位作者 Lulwa Ali Ali. AI-Dousari 《Journal of Environmental Science and Engineering(A)》 2012年第8期1025-1035,共11页
Surface sediment samples were collected from 35 locations in Sulaibikhat Bay, Kuwait. Co, Cr, Cu, Ni, Pb and Zn concentrations were determined. Grain sizes, TOC (total organic carbon), carbonate, mineralogical and e... Surface sediment samples were collected from 35 locations in Sulaibikhat Bay, Kuwait. Co, Cr, Cu, Ni, Pb and Zn concentrations were determined. Grain sizes, TOC (total organic carbon), carbonate, mineralogical and environmental data were also determined. Multiple linear regression is applied to the data from the sediment sequential extractions to assess the relative importance of mineralogical and sedimentological factors in controlling heavy metal concentrations in individual chemical fractions (exchangeable, reducible, oxidizable, residual) under different environmental conditions. The analysis shows that grain size, TOC, calcium carbonate and minerals clearly influence heavy metal concentrations. For the exchangeable fraction, clay, grain size and the mineral pyrite are the main factors, whereas for the reducible fraction, TOC is the main factor influencing concentrations ofZn, Pb, Ni, Cu and Cr. For the oxidizable fraction, modelling shows that TOC is the main factor influencing Zn, Ni, Cu, Cr and Co concentrations. The residual fraction concentrations of Zn, Ni, Cr and Co were best predicted by the abundance of sand, with sand content having a negative effect on heavy metal concentrations in this fraction. The statistical techniques in environmental data interpretation are quite useful in cutting down the volume of the data and identifying identical classes which are statistically distinct. 展开更多
关键词 Metals SEDIMENTS MINERALOGICAL CLAY sequential extraction sedimentological.
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A compartmentation approach to deconstruct ecosystem carbon fluxes of a Moso bamboo forest in subtropical China 被引量:1
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作者 Jianhua Lv Quan Li +4 位作者 Tingting Cao Man Shi Changhui Peng Lei Deng Xinzhang Song 《Forest Ecosystems》 2025年第2期300-310,共11页
Moso bamboo(Phyllostachys edulis)forests are a vital resource in subtropical China,known for their high carbon(C)sequestration capacity.However,the dynamic processes of C fluxes within each component(canopy,culm,and s... Moso bamboo(Phyllostachys edulis)forests are a vital resource in subtropical China,known for their high carbon(C)sequestration capacity.However,the dynamic processes of C fluxes within each component(canopy,culm,and soil)and their individual contributions,particularly during on-and off-years,remain unclear.A 2-year field experiment was conducted to investigate the dynamics of C fluxes from the canopy,culm,and soil(partitioned into heterotrophic,rhizome,and stump respiration)and their contributions to net ecosystem productivity(NEP)in a representative Moso bamboo forest in the subtropical region of China.The average annual NEP of the Moso bamboo forest was 7.31±2.76 t C·ha^(-1).Specifically,the canopy's annual net C uptake was 17.30±3.23 tC·ha^(-1),accounting for 237%of NEP.In contrast,C emissions from heterotrophs,culms,rhizomes,and stumps were 5.37±1.20,2.18±1.05,1.29±0.04,and 1.15±0.33 t C·ha^(-1),accounting for73%,30%,18%,and16%of NEP,respectively.The NEP,net cumulative C uptake in the canopy,and C emissions from the respiration of heterotrophs and stumps were all significantly higher during on-years when compared to off-years,whereas C emissions from bamboo culms displayed opposite trends.These findings offer a new approach for quantifying the C budgets of Moso bamboo forests and provide valuable insights into the C cycling processes in forest ecosystems. 展开更多
关键词 Carbon budget Ecosystem respiration Phyllostachys edulis Source-sink relations Stand age
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SEM Investigation of the Microstructure of Oxygen-Deficient Ca2FeGaO6-δ
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作者 Ariella Fogel Mandy Guinn Ram Krishna Hona 《Journal of Materials Science and Chemical Engineering》 2025年第1期1-6,共6页
This study presents a detailed investigation of the microstructure of the oxygen-deficient perovskite material Ca2FeGaO6-δ using Scanning Electron Microscopy (SEM). The material exhibits significant porosity and irre... This study presents a detailed investigation of the microstructure of the oxygen-deficient perovskite material Ca2FeGaO6-δ using Scanning Electron Microscopy (SEM). The material exhibits significant porosity and irregular grain morphology, with variations in grain size and growth. Unlike conventional perovskite structures, Ca2FeGaO6-δ shows non-uniform grain development, which can be attributed to the presence of oxygen vacancies (δ). SEM analysis reveals that the irregularities in grain size and shape, coupled with the porous nature of the material, are likely to influence its functional properties. These findings provide valuable insights into the structural features of Ca2FeGaO6-δ, offering a foundation for understanding its potential applications in catalysis, sensors, and other technologies. The study highlights the critical role of microstructural characteristics in determining the material’s performance. 展开更多
关键词 XRD Solid-State Reaction Perovskite Oxides Oxygen Deficiency SEM
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Challenges and opportunities in the energy transition of agribusiness:A deep dive into the rebound effect in Latin America
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作者 Fábio DE OLIVEIRA NEVES Eduardo Gomes SALGADO +2 位作者 Mateus CURY Jean Marcel Sousa LIRA Breno Régis SANTOS 《Regional Sustainability》 2025年第3期1-18,共18页
Growing climate change concerns have intensified the focus on agribusiness sustainability,driving an urgent energy transition to improve production efficiency and mitigate environmental harm.The complex interplay betw... Growing climate change concerns have intensified the focus on agribusiness sustainability,driving an urgent energy transition to improve production efficiency and mitigate environmental harm.The complex interplay between energy efficiency and energy consumption highlights the essential role of strategic energy policies in ensuring sustainable development.This study used the Double-Log regression model with bootstrap resampling to examine the rebound effect in the energy transition of agribusiness focusing on five Latin American countries including Brazil,Argentina,Uruguay,Colombia,and Mexico based on the agricultural sector data during 2010–2022.The findings revealed that the rebound effect significantly influences energy transition,with varying degrees of impact across agricultural sectors.This study identified partial rebound effect across all five countries,with elasticity coefficient varying from 9.63%(Colombia’s coffee sector)to 89.12%(Brazil’s livestock sector).In Brazil’s sugarcane sector,nonrenewable energy,agricultural employment,and irrigation efficiency were identified as key factors influencing energy consumption,while in livestock sector,energy consumption was affected by CH_(4)emissions,income and well-being of farmers,water consumption,and water conservation practices.In Mexico’s livestock sector,CH_(4)emissions,nonrenewable energy,and water conservation practices were the key factors affecting energy consumption.In Argentina’s sugarcane sector,pesticides,NO_(2)emissions,renewable energy,and agricultural employment were the key factors affecting energy consumption,while renewable energy,income and well-being of farmers,and water consumption were the key factors affecting energy consumption in livestock sector.In Uruguay’s livestock sector,non-renewable energy,income and well-being of farmers,and irrigation efficiency were the key factors affecting energy consumption.In Colombia’coffee sector,NO_(2)emissions and irrigation efficiency were identified as key factors influencing energy consumption.Finally,this study reinforces the importance of aligning energy transition with Sustainable Development Goals(SDGs),ensuring that energy efficiency gains do not inadvertently increase energy consumption or environmental degradation. 展开更多
关键词 Energy efficiency Energy consumption Greenhouse gas emissions Rebound effect Double-Log regression model Latin America
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Effective bromate removal from water utilizing ZIF-67 and ZIF-67/GO nanocomposites:Optimization and mechanism analysis
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作者 Alaa El Din Mahmoud Rominder Suri 《Water Science and Engineering》 2025年第3期301-311,共11页
Bromate(BrO_(3)^(−))is a toxic disinfection byproduct frequently formed during ozonation in water treatment processes and is classified as a potential human carcinogen.Its effective removal from drinking water is ther... Bromate(BrO_(3)^(−))is a toxic disinfection byproduct frequently formed during ozonation in water treatment processes and is classified as a potential human carcinogen.Its effective removal from drinking water is therefore a pressing concern for public health and environmental safety.This study investigated the removal of BrO_(3)^(−)from water using the synthesized zeolite imidazolate framework(ZIF)-67 and ZIF-67/graphene oxide(GO)nanocomposites through a comparative approach.The morphology,composition,and crystallinity of both ZIFs were characterized.The effects of four independent parameters(initial BrO_(3)^(−)concentration,pH,adsorbent dose,and contact time)on BrO_(3)^(−)removal efficiency were examined.A strong correlation was observed between experimental and predicted values.GO enhanced BrO_(3)^(−)removal not only through synergistic interactions with ZIF-67 but also by improving dispersion and providing additional functional groups that facilitate electrostatic interactions and adsorption.The Box-Behnken design was employed to evaluate both individual and interactive effects of the parameters on BrO_(3)^(−)removal,achieving an optimum removal efficiency of approximately 99.6%using 1.5 g/L of ZIF-67/GO at a pH value of 4 with an initial BrO_(3)^(−)concentration of 2 mg/L.The optimization process was further supported by desirability analysis.The BrO_(3)^(−)removal mechanisms are primarily attributed to porosity,electrostatic interactions,and adsorption onto active sites.Compared to ZIF-67 alone,ZIF-67/GO demonstrated superior anion removal efficiency,highlighting its potential for water treatment applications. 展开更多
关键词 ZIF-67 Graphene oxide NANOCOMPOSITE BrO_(3)^(−) Anion removal Mechanism Synergistic effect Response surface methodology
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Ozone exposure alters nutrients and stoichiometric ratios in different organs of four urban tree species despite limited negative effects on leaf physiology and plant growth and biomass
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作者 Kun Zhang Shenglan Li +7 位作者 Shuangjiang Li Bo Shang Costas J.Saitanis Yansen Xu Chao Fang George Papadopoulos Zhaozhong Feng Evgenios Agathokleous 《Journal of Forestry Research》 2025年第3期84-106,共23页
To better understand the effects of ground-level ozone(O_(3))on nutrients and stoichiometry in different plant organs,urban tree species Celtis sinensis,Cyclocarya paliu-rus,Quercus acutissima,and Quercus nuttallii we... To better understand the effects of ground-level ozone(O_(3))on nutrients and stoichiometry in different plant organs,urban tree species Celtis sinensis,Cyclocarya paliu-rus,Quercus acutissima,and Quercus nuttallii were sub-jected to a constant exposure to charcoal-filtered air(CF),nonfiltered air(NF),or NF+40,60,or 80 nmol O_(3)mol^(-1)(NF40,NF60,and NF80)starting early in the summer of the growing season.At the end of summer,net CO_(2)assimila-tion rate(A),stomatal conductance(gs),leaf mass per area(LMA),and/or leaf greenness(SPAD)either were not sig-nificantly affected by elevated O_(3)or were even higher in some cases during the summer compared with the CF or NF controls.LMA was significantly lower in autumn only after the highest O_(3)exposures.Compared to NF,NF40 caused a large increase in gs across species in late summer and more K and Mn in stems.At the end of the growing season,nutri-ent status and stoichiometric ratios in different organs were variously altered under O_(3)stress;many changes were large and often species-specific.Across O_(3)treatments,LMA was primarily associated with C and Mg levels in leaves and Ca levels in leaves and stems.NF40 enriched K,P,Fe,and Mn in stems,relative to NF,and NF60 enhanced Ca in leaves relative to CF and NF40.Moreover,NF resulted in a higher Ca/Mg ratio in leaves of Q.acutissima only,relative to the other O_(3)regimes.Interestingly,across species,O_(3)stress led to different nutrient modifications in different organs(stems+branches vs leaves).Thus,ambient and/or elevated O_(3)exposures can alter the dynamics and distribution of nutrients and disrupt stoichiometry in different organs in a species-specific manner.Changes in stoichiometry reflect an important defense mechanism in plants under O_(3),and O_(3)pollution adds more risk to ecological stoichiometries in urban areas. 展开更多
关键词 Air pollution Ground-level ozone Urban green MICRONUTRIENTS Nutrient cycling
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Publisher Correction:Ozone exposure alters nutrients and stoichiometric ratios in different organs of four urban tree species despite limited negative effects on leaf physiology and plant growth and biomass
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作者 Kun Zhang Shenglan Li +7 位作者 Shuangjiang Li Bo Shang Costas J.Saitanis Yansen Xu Chao Fang George Papadopoulos Zhaozhong Feng Evgenios Agathokleous 《Journal of Forestry Research》 2025年第4期255-275,共21页
Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the p... Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the publisher's production process.The published incorrect version and the corrected version of Fig.4 are given below. 展开更多
关键词 plant growth BIOMASS leaf physiology urban tree species NUTRIENTS ozone exposure stoichiometric ratios
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北京市夏季低层大气NO_x、O_3垂直分布观测研究 被引量:16
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作者 刘烽 陈辉 Liu Yangang 《青岛海洋大学学报(自然科学版)》 CSCD 北大核心 2002年第2期179-185,共7页
根据 2 0 0 0年夏季在北京 32 5 m铁塔上的一次梯度观测实验 ,给出 8m,12 0 m和 2 80 m三层上的 NO、NO2 、O3 浓度的观测结果。对 NO,NO2 ,O3 小时平均浓度的日变化和垂直分布规律进行了分析 ,结果发现 :(1)各高度上的 NO,NO2 ,O3 浓... 根据 2 0 0 0年夏季在北京 32 5 m铁塔上的一次梯度观测实验 ,给出 8m,12 0 m和 2 80 m三层上的 NO、NO2 、O3 浓度的观测结果。对 NO,NO2 ,O3 小时平均浓度的日变化和垂直分布规律进行了分析 ,结果发现 :(1)各高度上的 NO,NO2 ,O3 浓度均有明显的日变化特征 ,阴雨天的日变化更加复杂 ;(2 ) O3 在晴朗白天有单、双及三峰型分布 ;(3)相对于 12 0 m和 2 80 m,近地面 8m处的 NO浓度最高 ,而 O3 浓度最低 ;(4) NO2 、O3 日平均浓度日变化振幅 12 0 m处最大 ;(5 )中午前后 NO,NO2 ,O3 浓度均在 12 0 m最高。 展开更多
关键词 臭氧 氮氧化物 城市大气边界层 北京市 夏季 日变化 垂直分布
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Effect of arsenic on spatial pattern of radial oxygen loss and iron plaque formation in rice 被引量:1
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作者 吴川 黄柳 +4 位作者 薛生国 潘炜松 邹奇 William Hartley 莫竞瑜 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第2期413-419,共7页
The effects of different arsenic (As) treatments on spatial pattern of radial oxygen loss (ROL), iron (Fe) plaque formation and As accumulation in rice were investigated using three rice genotypes, planted under... The effects of different arsenic (As) treatments on spatial pattern of radial oxygen loss (ROL), iron (Fe) plaque formation and As accumulation in rice were investigated using three rice genotypes, planted under greenhouse conditions. Arsenic was applied to soil at 50 and 100 mg/kg, with untreated soil used as a control having an average As concentration of 8.5 mg/kg. It was demonstrated that the ratio of ROL in root tips to that at the root base slightly decreased with increasing As concentration, suggesting that the spatial ROL patterns in these groups may be shifted from the “tight” barrier towards the “partial” barrier form. Furthermore, increasing As concentration led to a increase in Fe plaque formation on root surfaces. In addition, root As concentrations of genotypes in 50 and 100 mg/kg As treatments were significantly higher than that of control treatment (P〈0.05). Grain As concentration of genotype Nanyangzhan (with lower ROL) was significantly higher (P〈0.05) than that of genotype CNT87059-3 with higher ROL. 展开更多
关键词 ARSENIC iron plaque RICE spatial pattern of ROL
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利用N_2-Ar-He示踪法研究粤东嵩溪大型银锑矿成矿流体 被引量:3
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作者 孙晓明 D.I.Norman +2 位作者 孙凯 陈敬德 陈炳辉 《自然科学进展(国家重点实验室通讯)》 1999年第A12期1364-1367,共4页
嵩溪银锑矿是90年代初发现的一个大型新型独立银矿,其成因存在海底基性火山喷流和浅成中低温火山热液充填两种不同观点。前者认为成矿流体为海底热卤水,而后者则认为主要来自岩浆水,但有大气降水加入。较系统的N_2-Ar-He组成和He同位素... 嵩溪银锑矿是90年代初发现的一个大型新型独立银矿,其成因存在海底基性火山喷流和浅成中低温火山热液充填两种不同观点。前者认为成矿流体为海底热卤水,而后者则认为主要来自岩浆水,但有大气降水加入。较系统的N_2-Ar-He组成和He同位素研究清楚地显示嵩溪成矿流体主要来源于建造水或称沉积热卤水,其中幔源岩浆水的比例很小,一般<5%。从成矿流体来源看,嵩溪银锑矿成因类型应属沉积热卤水改造型。 展开更多
关键词 成矿流体 示踪法 沉积热点水 银锑矿
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森林与径流关系——一致性和复杂性 被引量:47
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作者 魏晓华 李文华 +2 位作者 周国逸 刘世荣 孙阁 《自然资源学报》 CSSCI CSCD 北大核心 2005年第5期761-770,共10页
@论文综述国外近一个世纪以来在配对集水区研究方面所取得的结论,从水的自然属性出发,从森林变化对径流(年径流量、洪峰与枯水径流)的影响,径流响应的干扰临界值及水文恢复各方面探讨森林变化与径流关系的一致性与复杂性。森林变化与径... @论文综述国外近一个世纪以来在配对集水区研究方面所取得的结论,从水的自然属性出发,从森林变化对径流(年径流量、洪峰与枯水径流)的影响,径流响应的干扰临界值及水文恢复各方面探讨森林变化与径流关系的一致性与复杂性。森林变化与径流关系的一致性主要表现在由较长时间尺度表达的年径流量上。绝大多数的配对集水区的试验研究表明,采伐森林就会增加年径流量,而在荒地上造林就会减少年径流量。而由较短时间尺度表达的洪峰径流与枯水流量则呈现较大的复杂性和难预估性。综述表明,对径流特别是洪峰与枯水径流的定义及分析方法的不同也是造成森林与径流关系复杂性的重要原因。森林与径流关系的复杂性要求人们在研究及应用其关系时就必须有系统观,必须考虑植被、径流与其它过程(土壤变化、气候变化等)的相互作用。论文还认为尽管配对集水区试验作为一种研究方法为研究者提供了许多可靠的结论,但由于许多研究者只把集水区看作是“黑箱”Q从而对认识森林与径流关系的复杂性有一定的局限性。未来的研究应把配对集水区的试验与其它对过程的研究技术(同位素、GIS等技术)结合起来。 展开更多
关键词 森林变化 年径流量 洪峰径流 枯水流量 水文恢复
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甘草内生细菌对4种植物病原菌的抑菌谱及其16SrRNA系统发育分析 被引量:6
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作者 祖丽皮亚木·木沙尔 李丽 +2 位作者 郭建伟 古丽斯玛依·艾拜都拉 OSAMA Mohamed 《西北农业学报》 CAS CSCD 北大核心 2018年第9期1367-1374,共8页
旨在筛选对4种植物病原真菌具有拮抗活性的甘草内生细菌,为新疆甘草内生细菌的开发应用提供理论依据。采用平板对峙培养法从100株甘草内生细菌中筛选对石榴枯萎病甘薯长喙壳、草果叶斑病镰刀菌、草果假茎黑斑病小孢拟盘多毛孢、墨兰炭... 旨在筛选对4种植物病原真菌具有拮抗活性的甘草内生细菌,为新疆甘草内生细菌的开发应用提供理论依据。采用平板对峙培养法从100株甘草内生细菌中筛选对石榴枯萎病甘薯长喙壳、草果叶斑病镰刀菌、草果假茎黑斑病小孢拟盘多毛孢、墨兰炭疽病胶孢炭疽菌等4个病原菌具有拮抗活性的菌株,并测定其16SrRNA基因序列,建立系统发育树对其进行初步鉴定。结果显示,61株菌株对甘薯长喙壳具有拮抗作用,其中13株菌的抑菌半径均大于15mm。进一步研究表明,10株菌对4种植物病原菌都表现出较高的抑菌能力。基于16Sr RNA基因序列分析与系统发育分析表明,其中11株菌为萎缩芽孢杆菌(Bacillus atrophaeus),另外2株菌分别为副氧化微杆菌(Microbacterium paraoxydans)和莫哈韦芽胞杆菌(B.mojavensis)。 展开更多
关键词 甘草内生细菌 植物病原菌 拮抗作用 系统发育
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Changes in distribution and microstructure of bauxite residue aggregates following amendments addition 被引量:23
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作者 Shengguo Xue Yuzhen Ye +3 位作者 Feng Zhu Qiongli Wang Jun Jiang William Hartley 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2019年第4期276-286,共11页
Bauxite residue is a highly alkaline byproduct which is routinely discarded at residue disposal areas. Improving soil formation process to revegetate the special degraded lands is a promising strategy for sustainable ... Bauxite residue is a highly alkaline byproduct which is routinely discarded at residue disposal areas. Improving soil formation process to revegetate the special degraded lands is a promising strategy for sustainable management of the refining industry. A laboratory incubation experiment was used to evaluate the effects of gypsum and vermicompost on stable aggregate formation of bauxite residue. Aggregate size distribution was quantified by fractal theory, whilst residue microstructure was determined by scanning electron microscopy and synchrotron-based X-ray micro-computed tomography. Amendments addition increased the content of macro-aggregates(> 250 μm) and enhanced aggregate stability of bauxite residue. Following gypsum and vermicompost addition, fractal dimension decreased from 2.84 to 2.77, which indicated a more homogeneous distribution of aggregate particles. Images from scanning electron microscopy and three-dimensional microstructure demonstrated that amendments stimulate the formation of improved structure in residue aggregates. Pore parameters including porosity, pore throat surface area, path length, and path tortuosity increased under amendment additions. Changes in aggregate size distribution and microstructure of bauxite residue indicated that additions of gypsum and vermicompost were beneficial to physical condition of bauxite residue which may enhance the ease of vegetation. 展开更多
关键词 BAUXITE RESIDUE FRACTAL characteristics AGGREGATE MICROSTRUCTURE Substrate amendment Soil formation
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Yield and Nicotine Content of Flue-Cured Tobacco as Affected by Soil Nitrogen Mineralization 被引量:46
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作者 JU Xiao-Tang CHAO Feng-Chun +3 位作者 LI Chun-Jian JIANG Rong-Feng P. CHRISTIE ZHANG Fu-Suo 《Pedosphere》 SCIE CAS CSCD 2008年第2期227-235,共9页
Nitrogen(N)supply is the most important factor affecting yield and quality of flue-cured tobacco(FCT).A field experiment and an in situ incubation method were used to study the effects of soil N mineralization in the ... Nitrogen(N)supply is the most important factor affecting yield and quality of flue-cured tobacco(FCT).A field experiment and an in situ incubation method were used to study the effects of soil N mineralization in the later stages of growth on yield and nicotine content of FCT in Fenggang and Jinsha,Guizhou Province.The yield and market value of FCT at Fenggang were much lower than those at Jinsha.However,the nicotine content of middle and upper leaves was much higher at Fenggang than at Jinsha when the same rate of fertilizer N was applied,which might be due to a higher N supply capacity at the Fenggang site.At later stages of growth(7-16 weeks after transplanting),the soil net N mineralization at Fenggang(56 kg N ha^(-1))was almost double that at Jinsha(30 kg N ha^(-1)).While soil NH_4-N and NO_3-N were almost exhausted by the plants or leached 5 weeks after transplanting,the N taken up at the later growth stages at Fenggang were mainly derived from soil N mineralization,which contributed to a high nicotine content in the upper leaves.The order of soil N contribution to N buildup in different leaves was:upper leaves>middle leaves>lower leaves.Thus,soil N mineralization at late growth stages was an important factor affecting N accumulation and therefore the nicotine content in the upper leaves. 展开更多
关键词 flue cured tobacco nicotine content soil N mineralization tobacco quality tobacco yield
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Industrial wastes applications for alkalinity regulation in bauxite residue:A comprehensive review 被引量:29
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作者 XUE Sheng-guo WU Yu-jun +5 位作者 LI Yi-wei KONG Xiang-feng ZHU Feng LI Xiao-fei YE Yu-zhen WILLIAM Hartley 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第2期268-288,共21页
Bauxite residue is a highly alkaline material generated from the production of alumina in which bauxite is dissolved in caustic soda.Approximately 4.4 billion tons of bauxite residues are either stockpiled or landfill... Bauxite residue is a highly alkaline material generated from the production of alumina in which bauxite is dissolved in caustic soda.Approximately 4.4 billion tons of bauxite residues are either stockpiled or landfilled,creating environmental risks either from the generation of dust or migration of filtrates.High alkalinity is the critical factor restricting complete utilization of bauxite residues,whilst the application of alkaline regulation agents is costly and difficult to apply widely.For now,current industrial wastes,such as waste acid,ammonia nitrogen wastewater,waste gypsum and biomass,have become major problems restricting the development of the social economy.Regulation of bauxite residues alkalinity by industrial waste was proposed to achieve‘waste control by waste’with good economic and ecological benefits.This review will focus on the origin and transformation of alkalinity in bauxite residues using typical industrial waste.It will propose key research directions with an emphasis on alkaline regulation by industrial waste,whilst also providing a scientific reference point for their potential use as amendments to enhance soil formation and establish vegetation on bauxite residue disposal areas(BRDAs)following large-scale disposal. 展开更多
关键词 bauxite residue alkalinity transformation alkalinity regulation industrial waste soil formation in bauxite residue
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Effect of Long-Term Fertilization on Organic Nitrogen Forms in a Calcareous Alluvial Soil on the North China Plain 被引量:16
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作者 JU Xiao-Tang LIU Xue-Jun +1 位作者 ZHANG Fu-Suo P. CHRISTIE 《Pedosphere》 SCIE CAS CSCD 2006年第2期224-229,共6页
In order to illustrate the change of nitrogen (N) supply capacity after long-term application of manure and chemical fertilizer, as well as to properly manage soil fertility through fertilizer application under the ... In order to illustrate the change of nitrogen (N) supply capacity after long-term application of manure and chemical fertilizer, as well as to properly manage soil fertility through fertilizer application under the soil-climatic conditions of the North China Plain, organic N forms were quantified in the topsoil with different manure and chemical fertilizer treatments in a 15-year fertilizer experiment in a Chinese calcareous alluvial soil. Soil total N (TN) and various organic N forms were significantly influenced by long-term application of chemical fertilizer and manure. TN, total hydrolysable N, acid-lnsoluble N, amino acid N and ammonium N in the soil increased significantly (P 〈 0.05) with increasing manure and fertilizer N rates, but were not influenced by increasing P rates. Also, application of manure or N fertilizer or P fertilizer did not significantly influence either the quantity of amino sugar N or its proportion of TN. Application of manure significantly increased (P 〈 0.05) hydrolysable unknown N, but adding N or P did not. In addition, application of manure or N fertilizer or P fertilizer did not significantly influence the proportions of different soil organic N forms. 展开更多
关键词 chemical fertilizer long-term fertilization MANURE North China Plain soil organic nitrogen forms
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Variations between rice cultivars in iron and manganese plaque on roots and the relation with plant cadmium uptake 被引量:49
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作者 Jianguo Liu Changxun Cao +2 位作者 Minghung Wong Zhijun Zhang Yuhong Chai 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第7期1067-1072,共6页
To understand certain mechanisms causing variations between rice cultivars with regard to cadmium uptake and tolerance, pot soil experiments were conducted with two rice cultivars of different genotypes under differen... To understand certain mechanisms causing variations between rice cultivars with regard to cadmium uptake and tolerance, pot soil experiments were conducted with two rice cultivars of different genotypes under different soil Cd levels. The relationships between plant Cd uptake and iron/manganese (Fe/Mn) plaque formation on roots were investigated. The results showed that rice cultivars differed markedly in Cd uptake and tolerance. Under soil Cd treatments, Cd concentrations and accumulations in the cultivar Shanyou 63 (the genotype indica) were significantly higher than those in the cultivar Wuyunjing 7 (the genotype japonica) (P 〈 0.01, or P 〈 0.05), and Shanyou 63 was more sensitive to Cd toxicity than Wuyunjing 7. The differences between the rice cultivars were the largest at relatively low soil Cd level (i.e., 10 mg/kg). Fe concentrations in dithionite-citrate-bicarbonate root extracts of Shanyou 63 were generally lower than that of Wuyunjing 7, and the difference was the most significant under the treatment of 10 mg Cd/kg soil. The results indicated that the formation of iron plaque on rice roots could act as a barrier to soil Cd toxicity, and may be a "buffer" or a "reservoir" which could reduce Cd uptake into rice roots. And the plaque may contribute, to some extent, to the genotypic differences of rice cultivars in Cd uptake and tolerance. 展开更多
关键词 rice (Orvza sativa L.) CADMIUM zenotype iron/manganese plaque
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Modeling the effects of constructed wetland on nonpoint source pollution control and reservoir water quality improvement 被引量:7
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作者 Jonghwa Ham Chun G.Yoon +1 位作者 Hyung-Joong Kim Hyung-Chul Kim 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第6期834-839,共6页
This article describes the integrated modeling approach for planning the size and the operation of constructed wetlands for maximizing retention of nonpoint source pollutant loads and reservoir water-quality improveme... This article describes the integrated modeling approach for planning the size and the operation of constructed wetlands for maximizing retention of nonpoint source pollutant loads and reservoir water-quality improvement at a catchment scale. The experimental field-scale wetland systems (four sets, 0.88 ha each) have been in operation since 2002, where water depth was maintained at 30-50 cm and hydraulic loading rate was at 6.3-18.8 cm/day. The wetland system was found to be adequate for treating polluted stream water with stable removal efficiency even during the winter. The integrated modeling system (modified-BASINS) was applied to the Seokmoon estuarine reservoir watershed and calibrated with monitoring data from constructed wetland, stream, and reservoir. The calibrated integrated modeling system estimated that constructing wetlands on 0.5% (about 114 ha) of the watershed area at the mouth of reservoir could reduce 11.61% and 13.49% of total external nitrogen and phosphorus loads, respectively. It also might improve the nitrogen and phosphorus concentration of the reservoir by 9.69% and 16.48%, respectively. The study suggested that about 0.1%-1.0% of the watershed area should be allocated for constructed wetland to meet specified water-quality standards for the estuarine reservoir at the polder area where land use planning is relatively less complicated. 展开更多
关键词 constructed wetland estuarine reservoir integrated modeling system nonpoint source pollution control polder area water quality improvement
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