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Systematic Review of Machine Learning Applications in Sustainable Agriculture:Insights on Soil Health and Crop Improvement
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作者 Vicky Anand Priyadarshani Rajput +4 位作者 Tatiana Minkina Saglara Mandzhieva Santosh Kumar Avnish Chauhan Vishnu D.Rajput 《Phyton-International Journal of Experimental Botany》 2025年第5期1339-1365,共27页
The digital revolution in agriculture has introduced data-driven decision-making,where artificial intelligence,especially machine learning(ML),helps analyze large and varied data sources to improve soil quality and cr... The digital revolution in agriculture has introduced data-driven decision-making,where artificial intelligence,especially machine learning(ML),helps analyze large and varied data sources to improve soil quality and crop growth indices.Thus,a thorough evaluation of scientific publications from 2007 to 2024 was conducted via the Scopus and Web of Science databases with the PRISMA guidelines to determine the realistic role of ML in soil health and crop improvement under the SDGs.In addition,the present review focused to identify and analyze the trends,challenges,and opportunities associated with the successful implementation of ML in agriculture.The assessment of various databases clearly revealed that ML implementation depends on crop management,while its limited potential in terms of soil health was explored.ML models,such as random forest and XGBoost,have demonstrated high accuracies of up to 99%in crop yield prediction and disease detection.Advanced ML frameworks,including the SHIDS-ADLT and EfficientNetB3,have improved soil health monitoring and plant disease classification.Irrigation management using ML has achieved over 50%water savings and irrigation efficiency by 10%-35%.These findings highlight the potential of ML to improve sustainable agricultural practices and soil health.A significant improvement discussed in this review is AutoML,which simplifies ML model implementation by automating feature selection,model selection,and hyperparameter tuning,reducing dependency on ML expertise.The integration of ML with remote sensing,Internet of Things(IoT),and big data analytics is expected to further transform the precision agriculture and real-time decisionmaking approaches to optimize resource utilization.Conclusively,the present review offers a quantitative perspective on the evolution of ML in agriculture,soil health management,crop yield prediction,and resource optimization. 展开更多
关键词 CROPS IRRIGATION plant nutrients scientometric analysis soil health management SUSTAINABILITY
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Photochemical degradation of environmentally persistent perfluorooctanoic acid (PFOA) in the presence of Fe(Ⅲ) 被引量:3
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作者 Yuan Wang Peng Yi Zhang +1 位作者 Gang pan Hao chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第3期371-374,共4页
Environmentally persistent and bioaccumulative perfluorooctanic acid (PFOA) was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe(Ⅲ), 80% of PFOA with i... Environmentally persistent and bioaccumulative perfluorooctanic acid (PFOA) was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe(Ⅲ), 80% of PFOA with initial concentration of 48μmol/L (20 mg/L) was effectively degraded and 47.8% of fluorine atoms in PFOA molecule were transformed into inorganic fluoride ion after 4 h reaction. Shorter chain perfluorocarboxylic acids bearing C3-C7 and fluoride ion were detected and identified by LC/MS and IC as the degradation products in the aqueous solution. It was proposed that complexes of PFOA with Fe(Ⅲ) initiated degradation of PFOA irradiated with 254 nm UV light. 展开更多
关键词 Perfluorooctanoic acid Iron(Ⅲ) Photochemical degradation 254 nm UV light
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Environmental Impacts of Solid Waste Landfills on Natural Ecosystems of Southern Caspian Sea Coastlines
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作者 Seyed Masoud Monavari Sanaz Tajziehchi Razieh Rahimi 《Journal of Environmental Protection》 2013年第12期1453-1460,共8页
The problem of solid waste landfills on Caspian Sea coastlines is one of the current concerns of the Iranian environmental authorities. Physical and environmental constraints as well as shortcomings in present municip... The problem of solid waste landfills on Caspian Sea coastlines is one of the current concerns of the Iranian environmental authorities. Physical and environmental constraints as well as shortcomings in present municipal solid waste management are the main factors for environmental pollution and natural resources destruction in this geographical region. In order to reduce the above problems, this study has been carried out on the basis of a comparative assessment of the existing condition of landfill sites in natural ecosystems. In this study, 48 cities of the region have been investigated. All of them are located in Gilan and Mazandaran provinces. Total daily waste production in the study area is about 1209 tons that are dumped in open spaces and/or in aquatic and terrestrial ecosystems. Surveying of 53 physical, adaptability and constraint parameters as well as hygiene and environmental parameters in the landfills, based on “Monavari-94 Method” indicate that the main problem in all of them is a high groundwater table. In 42% of landfills, the groundwater level is between from 0.5 to 2 meters. This phenomenon may cause severe risks due to the infiltration of leachate into potable groundwater. Indeed, the results of the study show that 87.5% of the landfills are located in areas with unacceptable conditions. In spite of geographical and environmental problems and constraints and as a final alternative in this respect, the need for sanitary and technical solid waste management is the main need of the study areas. 展开更多
关键词 ECOSYSTEMS Solid Waste LANDFILL Water Pollution Caspian Sea COASTLINES
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Planetary Homeostasis of Reactive Nitrogen Through Anaerobic Ammonium Oxidation 被引量:1
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作者 Guibing Zhu Bangrui Lan +8 位作者 Shuci Liu Cameron M.Callbeck Shanyun Wang Liping Jiang Asheesh Kumar Yadav Jan Vymazal Mike S.M.Jetten Ganlin Zhang Yongguan Zhu 《Engineering》 SCIE EI CAS CSCD 2024年第7期175-183,共9页
The availability of nitrogen(N)is crucial for both the productivity of terrestrial and aquatic ecosystems globally.However,the overuse of artificial fertilizers and the energy required to fix nitrogen have pushed the ... The availability of nitrogen(N)is crucial for both the productivity of terrestrial and aquatic ecosystems globally.However,the overuse of artificial fertilizers and the energy required to fix nitrogen have pushed the global nitrogen cycle(N-cycle)past its safe operating limits,leading to severe nitrogen pollution and the production of significant amounts of greenhouse gas nitrous oxide(N2O).The anaerobic ammonium oxidation(anammox)mechanism can counteract the release of ammonium and N2O in many oxygenlimited situations,assisting in the restoration of the homeostasis of the Earth’s N biogeochemistry.In this work,we looked into the characteristics of the anammox hotspots’distribution across various types of ecosystems worldwide.Anammox hotspots are present at diverse oxic-anoxic interfaces in terrestrial systems,and they are most prevalent at the oxic-anoxic transition zone in aquatic ecosystems.Based on the discovery of an anammox hotspot capable of oxidizing ammonium anoxically into N2 without N2O by-product,we then designed an innovative concept and technical routes of nature-based anammox hotspot geoengineering for climate change,biodiversity loss,and efficient utilization of water resources.After 15 years of actual use,anammox hotspot geoengineering has proven to be effective in ensuring clean drinking water,regulating the climate,fostering plant and animal diversity,and enhancing longterm environmental quality.The sustainable biogeoengineering of anammox could be a workable natural remedy to resolve the conflicts between environmental pollution and food security connected to N management. 展开更多
关键词 Biogeochemical N-cycle Oxic-anoxic interface Nature-based solution Biogeoengineering Nitrogen sustainable development
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Synergistic extraction of rare earth elements and alumina from coal fly ash by potassium pyrosulfate
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作者 Jingjing Zou Yiping Sun +4 位作者 Chunbin Guo Daye Chen Yonghong Song Yongfeng Wu Zhaotianhui Li 《Journal of Rare Earths》 SCIE EI CAS CSCD 2024年第4期749-758,共10页
Although coal fly ash(CFA)contains a high content of rare earth elements(REEs),the related extraction methods have limitations because of their low efficiencies,high levels of energy consumption,and other drawbacks.To... Although coal fly ash(CFA)contains a high content of rare earth elements(REEs),the related extraction methods have limitations because of their low efficiencies,high levels of energy consumption,and other drawbacks.To address these problems,in this study,we examined the coextraction of REEs and Al_(2)O_(3)from two types of Al_(2)O_(3)-rich CFA,pulverized CFA(PCFA)and circulating fluidized bed fly ash(CFBFA)using low-temperature calcination in the presence of K_(2)S_(2)O_(7).The total REEs,heavy REEs(HREEs),and light REEs(LREEs)extraction efficiencies were determined using different K_(2)S_(2)O_(7)/Al_(2)O_(3) molar ratios and calcination temperatures and correlated with the Al_(2)O_(3) extraction efficiency using Pearson correlation coefficient analysis.The REEs are concentrated within CFA particles encapsulated in an aluminosilicate glass phase,and the REEs extraction efficiency is related to the form of Al in CFA.The extraction efficiencies of Al_(2)O_(3) and REEs increase as the K_(2)S_(2)O_(7)/Al_(2)O_(3) molar ratio and calcination temperature increase,and the extraction selectivity of the more industrially valuable HREEs from CFBFA is higher.At high K_(2)S_(2)O_(7)/Al_(2)O_(3) molar ratios,the extraction of REEs from PCFA is more efficient than that from CFBFA with the regeneration of the highly active Al-O-Si bonds in CFBFA.The Al_(2)O_(3) extraction efficiencies of PCFA as well as CFBFA correlate strongly with the total REEs,HREEs,and LREEs extraction efficiencies.The developed extraction technology has the potential to promote CFA valorization and expand REEs resources,thus mitigating the bottlenecks of REEs procurement. 展开更多
关键词 Rare earths ALUMINA Coal fly ash Potassium pyrosulfate CALCINATION EXTRACTION
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Chemical Composition of PM_(2.5) at an Urban Site of Chengdu in Southwestern China 被引量:25
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作者 陶俊 成天涛 +5 位作者 张仁健 曹军骥 朱李华 王启元 罗磊 张雷鸣 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2013年第4期1070-1084,共15页
PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous mat- ter. The ann... PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous mat- ter. The annual average of PM2.5 was 165 btg m a, which is generally higher than measurements in other Chinese cities, suggesting serious particulate pollution issues in the city. Water soluble ions contributed 43.5% to the annual total PM2.5 mass, carbonaceous aerosols including elemental carbon and organic car- bon contributed 32.0%, and trace elements contributed 13.8~0. Distinct daily and seasonal variations were observed in the mass concentrations of PM2.5 and its components, reflecting the seasonal variations of dif- ferent anthropogenic and natural sources. Weakly acidic to neutral particles were found for PMz5. Major sources of PM2.u identified from source apportionment analysis included coal combustion, traffic exhaust, biomass burning, soil dust, and construction dust emissions. The low nitrate: sulfate ratio suggested that stationary emissions were more important than vehicle emissions. The reconstructed masses of ammonium sulfate, ammonium nitrate, particulate carbonaceous matter, and fine soil accounted for 79% of the total measured PM2.5 mass; they also accounted for 92% of the total measured particle scattering. 展开更多
关键词 water soluble ions carbonaceous matters trace elements enrichment factor source appor tionment mass closure
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A Spectral Index for Estimating Soil Salinity in the Yellow River Delta Region of China Using EO-1 Hyperion Data 被引量:56
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作者 WENG Yong-Ling GONG Peng ZHU Zhi-Liang 《Pedosphere》 SCIE CAS CSCD 2010年第3期378-388,共11页
Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory an... Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory and hyperspectral data were acquired from an EO-1 Hyperion sensor to quantitatively map soil salinity in the region. A soil salinity spectral index (SSI) was constructed from continuum-removed reflectance (CR-reflectance) at 2052 and 2203 nm, to analyze the spectral absorption features of the salt-affected soils. There existed a strong correlation (r = 0.91) between the SSI and soil salt content (SSC). Then, a model for estimation of SSC with SSI was established using univariate regression and validation of the model yielded a root mean square error (RMSE) of 0.986 and an R2 of 0.873. The model was applied to a Hyperion reflectance image on a pixel-by-pixel basis and the resulting quantitative salinity map was validated successfully with RMSE = 1.921 and R2 = 0.627. These suggested that the satellite hyperspectral data had the potential for predicting SSC in a large area. 展开更多
关键词 hyperspectral reflectance soil salt content spectral absorption features
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Identification and Metabolic Mechanism of Non-fermentative Short-cut Denitrifying Phosphorus-removing Bacteria 被引量:12
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作者 刘晖 孙彦富 +5 位作者 贾晓珊 李军 周康群 屈向东 陶雪琴 陈瑜 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第3期332-340,共9页
To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria (SDPB) that are capable of enhanced biological phosphorus removal (EBPR) using nitrite as an elec... To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria (SDPB) that are capable of enhanced biological phosphorus removal (EBPR) using nitrite as an electron acceptor, an aerobic/anoxic sequencing batch reactor was operated under three phases. An SDPB-strain YC was screened after the sludge enrichment and was identified by morphological, physiological, biochemical properties and 16S rDNA gene sequence analysis. Denitrifying phosphorus-removing experiments were conducted to study anaerobic and anoxic metabolic mechanisms by analyzing the changes of chemical oxygen demand (COD), phosphate, nitrite, poly-fl-hydroxybutyrate (PHB), and glycogen. The results show that strain YC is a non-fermentative SDPB similar to Paracoccus denitrificans. As a kind of non-fermentative bacteria, the energy of strain YC was mainly generated from phosphorus release (96.2%) under anaerobic conditions with 0.32 mg P per mg synthesized PHB. Under anoxic conditions, strain YC accumulated 0.45 mg P per mg degraded PHB, which produced most of energy for phosphate accumulation (91.3%) and a little for glycogen synthesis (8.7%). This metabolic mechanism of strain YC is different from that of traditional phosphorus-accumulating organisms (PAOs). It is also found that PHB, a kind of intracellular polymer, plays a very important role in denitrifying and accumulating phosphorus by supplying sufficient energy for phosphorous accumulation and carbon sources for denitrification. Therefore, monitoring AP/APHB and ANO2 -N/APHB is more necessary than monitoring AP/ACOD, ANO2 -N/ACOD, or AP / ANO2 -N. 展开更多
关键词 short-cut denitrifying phosphorus removing bacteria Paracoccus denitrificans non-fermentative bac- teria metabolic mechanism poly-fl-hydroxybutyrate
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Effect of Abiotic Factors on the Mercury Reduction Process by Humic Acids in Aqueous Systems 被引量:7
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作者 JIANG Tao WEI Shi-Qiang +4 位作者 D.C.FLANAGAN LI Meng-Jie LI Xue-Mei WANG Qiang LUO Chang 《Pedosphere》 SCIE CAS CSCD 2014年第1期125-136,共12页
As a global pollutant process, the reduction of mercury (Hg) is especially important. One pathway is through an abiotic reduction with humic acids (HAs), which is controlled by different factors, including initial... As a global pollutant process, the reduction of mercury (Hg) is especially important. One pathway is through an abiotic reduction with humic acids (HAs), which is controlled by different factors, including initial Hg and HA concentrations, pH, temperature and light. In this study, three humic acids were selected to illustrate the Hg2+ abiotic reduction mechanisms by HAs, and to identify the key limiting factors for reduction rates and amounts. In addition, the initial status of the HAs as a solid or in an aqueous solution were also compared, to help explain why HAs show different dominant characteristics (e.g. complexation or reduction) in the reaction process with Hg. Results indicated that HAs were able to reduce Hg abiotically. Higher initial Hg, higher HA concentrations and either high (8.1) or low (3.6) solution pH decreased the HA reduction capacity. In addition, Hg~ production rates increased with increasing temperature, and the same trend was observed with light exposure. Humic acids added as an aqueous solution resulted in significantly greater HgO production than addition as a bulk solid. Finally, the Hg reduction rate and capacity varied significantly (P 〈 0.05) with HAs from different sources. These findings helped to explain why HAs showed different dominant characteristics (e.g. complexation or reduction) in the reaction process with of Hg2+ reduction, which indicated that humic substances in sink or a source for Hg. Hg, and evidentially demonstrated the existence of a possible pathway natural environments, especially in water bodies, could act either as a 展开更多
关键词 abiotic reduction COMPLEXATION humic substance natural organic matter
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Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings 被引量:15
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作者 DAI Cheng-Ying GAO Zhi-Qiu +1 位作者 WANG Qing CHENG Gang 《Atmospheric and Oceanic Science Letters》 2011年第2期124-130,共7页
Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating ag... Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating against the'true'ABL height from aircraft sounding profiles, where ABL height is defined as the top of the layer with significant turbulence. Furthermore, the best performing method was used to estimate ABL height from the one-year GPS soundings obtained during SHEBA (October 1997-October 1998). It was found that the temperature gradient method produces a reliable estimate of ABL height. Additionally, the authors determined optimal threshold values of temperature gradient for stable boundary layer (SBL) and convective boundary layer (CBL) to be 6.5 K/100 m and 1.0 K/100 m, respectively. The maximum ABL height during the year was 1150 m occurred in May. Median values of Arctic ABL height in May, June, July, and August were 400 m, 430 m, 180 m, and 320 m, respectively. Arctic ABL heights are clearly higher in the spring than in the summer. 展开更多
关键词 aircraft sounding Arctic boundary layer boundary layer height GPS sounding turbulence
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The Characteristics and Parameterization of Aerodynamic Roughness Length over Heterogeneous Surfaces 被引量:11
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作者 卢俐 刘绍民 +4 位作者 徐自为 阳坤 蔡旭辉 贾立 王介民 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2009年第1期180-190,共11页
Aerodynamic roughness length (Z0m) is a key factor in surface flux estimations with remote sensing algorithms and/or land surface models. This paper calculates ZOrn over several land surfaces, with 3 years of experi... Aerodynamic roughness length (Z0m) is a key factor in surface flux estimations with remote sensing algorithms and/or land surface models. This paper calculates ZOrn over several land surfaces, with 3 years of experimental data from Xiaotangshan. The results show that Z0m is direction-dependent, mainly due to the heterogeneity of the size and spatial distribution of the roughness elements inside the source area along different wind directions. Furthermore, a heuristic parameterization of the aerodynamic roughness length for heterogeneous surfaces is proposed. Individual Z0m over each surface component (patch) is calculated firstly with the characteristic parameters of the roughness elements (vegetation height, leaf area index, etc.), then Z0m over the whole experimental field is aggregated, using the footprint weighting method. 展开更多
关键词 aerodynamic roughness length heterogeneous surfaces FOOTPRINT
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Biogeochemical cyclic activity of bacterial arsB in arsenic-contaminated mines 被引量:5
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作者 CHANG Jin-Soo KIM Kyoung-Woong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第11期1348-1355,共8页
Biogeochemical cyclic activity of the ars (arsenic resistance system) operon is arsB influx/effux encoded by the ecological of Pseudomonas putida.This suggests that studying arsenite-oxidizing bacteria may lead to a b... Biogeochemical cyclic activity of the ars (arsenic resistance system) operon is arsB influx/effux encoded by the ecological of Pseudomonas putida.This suggests that studying arsenite-oxidizing bacteria may lead to a better understanding of molecular geomicrobiology,which can be applied to the bioremediation of arsenic-contaminated mines.This is the first report in which multiple arsB-binding mechanisms have been used on indigenous bacteria.In ArsB (strains OS-5; ABB83931; OS-19; ABB04282 and RW-28; ABB88574... 展开更多
关键词 arsenic resistance bacteria arsB influx/efflux pump arsenic resistance system (ars) biogeochemical
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Effect of Preparation Methods of Bi_(2)O_(3) Nanoparticles on their Photocatalytic Activity 被引量:5
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作者 DING Peng DU Yao-guo XU Zi-li 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第6期717-721,共5页
Bi 2O 3 nanoparticles were prepared by means of ammonia precipitation, polyol mediated methods and microemulsion chemical method. The structure and properties of the as-prepared nanoparticles, having been submitted to... Bi 2O 3 nanoparticles were prepared by means of ammonia precipitation, polyol mediated methods and microemulsion chemical method. The structure and properties of the as-prepared nanoparticles, having been submitted to a heat-treatment test at 750 ℃, were characterized by means of XRD, BET, XPS and UV-Vis absorption techniques. The photocatalytic oxidation reactions of benzene, toluene and xylene were used as the model reaction to measure the photocatalytic activity of Bi 2O 3 nanoparticles, respectively. The results show that the crystallite size of Bi 2O 3 prepared with different methods and calcined at 750 ℃ were 50.6, 38.5 and 31.5 nm, respectively. The photocatalytic activity of Bi 2O 3 nanoparticles prepared with the microemulsion chemical method was higher than that of the particles prepared with the polyol mediated method; and that of the particles prepared with the micromulsion chemical method was the highest among the three. The degradation rates of the three pollutants xylene, toluene and benzene decreased in sequence. 展开更多
关键词 Bi_(2)O_(3) Preparation method CHARACTERIZATION Photocatalytic activity
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Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions 被引量:3
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作者 GAO Da-wen WEN Xiang-hua QIAN Yi 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第3期428-432,共5页
Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is trea... Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-sterile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; in the meantime, a lot of yeast funguses were found in liquid medium when white rot fungus was incubated under non-sterile conditions; however, if white rot fungus was incubated under sterile condition firstly, its decolorization was above 90% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be divided into two stages. The first stage is that white rot fungus should be incubated under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile condition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions. 展开更多
关键词 white rot fungus Phanerochaete chrysosporium reactive brilliant red K-2BP DECOLORIZATION non-sterile condition
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Formation and structure of composite coating of HDA and micro-plasma oxidation on A3 steel 被引量:4
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作者 YU Sheng-xue XIA Yuan CHEN Ling GUAN Yong-jun YAO Mei 《中国有色金属学会会刊:英文版》 CSCD 2004年第z1期310-314,共5页
Composite coatings were obtained on A3 steel by hot dipping aluminum(HDA) at 720 ℃ for 6 min and micro-plasma oxidation(MPO) in alkali electrolyte. The surface morphology, element distribution and interface structure... Composite coatings were obtained on A3 steel by hot dipping aluminum(HDA) at 720 ℃ for 6 min and micro-plasma oxidation(MPO) in alkali electrolyte. The surface morphology, element distribution and interface structure of composite coatings were studied by means of XRD, SEM and EDS. The results show that the composite coatings obtained through HDA/MPO on A3 steel consist of four layers. From the surface to the substrate, the layer is loose Al2O3 ceramic, compact Al2O3 ceramic, Al and FeAl intermetallic compound layer in turn. The adhesions among all the layers are strengthened because the ceramic layer formed at the Al surface originally, FeAl intermetallic compound layer and substrate are combined in metallurgical form through mutual diffusion during HDA process.Initial experiment results disclose that the anti-corrosion performance and wear resistance of composite coating are obviously improved through HDA/MPO treatment. 展开更多
关键词 HOT dipping aluminum MICRO-PLASMA OXIDATION composite COATING CERAMIC COATING
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Iron stability in drinking water distribution systems in a city of China 被引量:2
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作者 NIU Zhang-bin WANG Yang +3 位作者 ZHANG Xiao-jian HE Wen-fie HAN Hong-da YIN Pei-jun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第1期40-46,共7页
A field study on the estimation and analysis of iron stability in drinking water distribution system was carried out in a city of China. The stability of iron ion was estimated by pC-pH figure. It was found that iron ... A field study on the estimation and analysis of iron stability in drinking water distribution system was carried out in a city of China. The stability of iron ion was estimated by pC-pH figure. It was found that iron ion was unstable, with a high Fe (OH)3 precipitation tendency and obvious increase in turbidity. The outer layer of the corrosion scale was compact, while the inner core was porous. The main composition of the scale was iron, and the possible compound constitutes of the outer scale were α-FeOH, γ-FeOOH, α-Fe2O3, γ-F2O3, FeCl3, while the inner were Fe3O4, FeCl2, FeCO3. According to the characteristics of the corrosion scale, it was thought that the main reason for iron instability was iron release from corrosion scale. Many factors such as pipe materials, dissolved oxygen and chlorine residual affect iron release. Generally, higher iron release occurred with lower dissolved oxygen or chlorine residual concentration, while lower iron release occurred with higher dissolved oxygen or chlorine residual concentration. The reason was considered that the passivated out layer of scale of ferric oxide was broken down by reductive reaction in a condition of low oxidants concentration, which would result more rapid corrosion of the nine and red water phenomenon. 展开更多
关键词 chlorine residual corrosion scale dissolved oxygen drinking water distribution systems iron release iron stability
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Effects of adsorption interferents on removal of Reactive Red 195 dye in wastewater by chitosan 被引量:2
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作者 WEN Yue-zhong LIU Wen-qi +1 位作者 FANG Zhao-hua LIU Wei-ping 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第5期766-769,共4页
Reactive Red 195, which is an azoic anionic dye characterized by the presence of five sulfonic groups and one azoic group, is efficiently removed using chitosan. The increasing chitosan dose had a dramatic positive im... Reactive Red 195, which is an azoic anionic dye characterized by the presence of five sulfonic groups and one azoic group, is efficiently removed using chitosan. The increasing chitosan dose had a dramatic positive impact on the achieved color removal, there was approximately a linear relationship between chitosan dose and color removal of dye before color removal reach maximum. Also, the increase of dye concentration led to the increase of chitosan dosage in order to get the same color remova l.92 mg/L of chitosan dosage was sufficient to achieve complete remove of dye at initial concentration of dye at 200 mg/L. For the higher concentrations of dye, high dosages were necessary to reach complete color removal. On the other hand, the use of adsorption interferents(Fe^2+ , Na^+ , HCO3^- and others) can be interesting, addition of ions had effect on the color removal of Reactive Red 195. Comparing with blank, addition of chemical species approximately decreased the color removal except Na^+ and combination of Fe^2+ + HCO3^- . However, comparing with Fe^2+ alone and HCO3^- alone, combination of Fe^2+ + HCO3^- increased the color removal. 展开更多
关键词 CHITOSAN Reactive Red 195 DYE COAGULATION color removal
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Photooxidation of Furfural with Phthalocyanine-sensitized TiO_2 Particle Under Xenon Lamp 被引量:2
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作者 KANG Chun-li LU Yu +3 位作者 GUO Ping ZHANG Fan YU Hong-bing LIN Xue-yu 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2007年第2期154-158,共5页
Copper phthalocyanine was selected as the photosensitizer to sensitize TiO2 in this experiment with furfural as the target pollutant. The composite catalysts(TiO2/CuPC) obtained showed a great activity under a xenon... Copper phthalocyanine was selected as the photosensitizer to sensitize TiO2 in this experiment with furfural as the target pollutant. The composite catalysts(TiO2/CuPC) obtained showed a great activity under a xenon lamp. By experiments, the optimal preparation conditions of the composite catalysts were set as follows : the CuPC loading mass fraction was 1.5%, the mass fraction of acetylacetone was 0. 3% , and the stirring time was 10 h. UV-Vis diffuse reflectance spectra, XRD, and BET were used to characterize the properties of the composite catalysts, which showed that after loading CuPC on TiO2, the composite catalyst retained the same crystal structure as pure TiO2 and the wavelength range of its absorption spectrum was broadened to 600-700 nm while its surface area was smaller than that of the pure TiO2. Under the optimal conditions, 20 mg/L furfural solution was degraded by nearly 90% and TOC by about 70%. When the catalyst was reused 6 times, the activity of the catalyst was still retained by about 75%. 展开更多
关键词 TiO2 CUPC Phthalocyanine-photosensitizer FURFURAL PHOTOOXIDATION
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Different environmental factors drive tree species diversity along elevation gradients in three climatic zones in Yunnan,southern China 被引量:3
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作者 Xiaoyang Song Min Cao +7 位作者 Jieqiong Li Roger L.Kitching Akihiro Nakamura Melinda J.Laidlaw Yong Tang Zhenhua Sun Wenfu Zhang Jie Yang 《Plant Diversity》 SCIE CAS CSCD 2021年第6期433-443,共11页
Elevational patterns of tree diversity are well studied worldwide.However,few studies have examined how seedlings respond to elevational gradients and whether their responses vary across climatic zones.In this study,w... Elevational patterns of tree diversity are well studied worldwide.However,few studies have examined how seedlings respond to elevational gradients and whether their responses vary across climatic zones.In this study,we established three elevational transects in tropical,subtropical and subalpine mountain forests in Yunnan Province,southern China,to examine the responses of tree species and their seedlings to elevational gradients.Within each transect,we calculated species diversity indices and composition of both adult trees and seedlings at different elevations.For both adult trees and seedlings,we found that species diversity decreased with increasing elevation in both tropical and subalpine transects.Species composition showed significant elevational separation within all three transects.Many species had specific elevational preferences,but abundant tree species that occurred at specific elevations tended to have very limited recruitment in the understory.Our results highlight that the major factors that determine elevational distributions of tree species vary across climatic zones.Specifically,we found that the contribution of air temperature to tree species composition increased from tropical to subalpine transects,whereas the contribution of soil moisture decreased across these transects. 展开更多
关键词 Air temperature Climate zones Montane forest Soil moisture SEEDLING Tree species distribution
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Adsorption and Transport of Ciprofloxacin in Quartz Sand at Different pH and Ionic Strength 被引量:2
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作者 Xiujiao Xu Jianglong He +2 位作者 Yu Li Zhaoxi Fang Shaohui Xu 《Open Journal of Soil Science》 2014年第12期407-416,共10页
Effects of pH and ionic strength on ciprofloxacin adsorption in quartz sand were studied through a batch equilibrium adsorption experiment in this paper. The experimental data were fitted by empirical formulas from La... Effects of pH and ionic strength on ciprofloxacin adsorption in quartz sand were studied through a batch equilibrium adsorption experiment in this paper. The experimental data were fitted by empirical formulas from Langmuir and Freundlich adsorption isothermal curves, and the transport experiments in quartz sand at different pH and ionic strength were conducted to investigate the transport characteristics of ciprofloxacin. It was found that with the increase of pH value or ionic strength, adsorption capacity of ciprofloxacin decreased, so that it could move easier. The results indicated that low pH or ionic strength was conductive to the adsorption of ciprofloxacin in quartz sand. Meanwhile, a higher initial concentration or stronger ionic strength could result in a smaller linear distribution coefficient of ciprofloxacin, which meant a low adsorption capacity. According to the fitting results, the adsorption of ciprofloxacin in quartz sand could be described well by both Langmuir and Freundlich equations, of which Freundlich equation had a better efficacy. 展开更多
关键词 CIPROFLOXACIN QUARTZ Sand PH IONIC Strength ISOTHERM ADSORPTION
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