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Investigation of Cu leaching from municipal solid waste incinerator bottom ash with a comprehensive approach

Jun YAO, Wenbing LI, Fangfang XIA, Jing WANG, Chengran FANG, Dongsheng SHEN

《能源前沿(英文)》 2011年 第5卷 第3期   页码 340-348 doi: 10.1007/s11708-010-0131-9

摘要: Municipal solid waste incinerator (MSWI) bottom ash is often reused as a secondary construction material. This study used a comprehensive approach to characterize the leaching behavior of copper (Cu) from the MSWI bottom ash. The batch titration procedure was used to determine the acid neutralizing capacity and Cu leaching as a function of pH. The sequential extraction procedure (SEP) was adopted to analyze the speciation of Cu in the MSWI bottom ash. The metal speciation equilibrium model for surface and ground water (Visual MINTEQ) was used to evaluate the equilibrium of the leachates with the relative minerals, and to determine the speciation of the aqueous Cu in the leachates. Based on the multi-analysis of the results, Cu would be significantly released from the MSWI bottom ash when it is acidic. The Cu leaching pattern was not only affected by dissolved organic carbon, it was also limited by its speciation in the MSWI bottom ash. Furthermore, almost 100% of the aqueous Cu in the leachate was bound to organic matter in basic and neutral conditions, but mostly existed as Cu in an acidic condition. These findings provide an important insight into predicting the leaching behavior of Cu from the MSWI bottom ash, as well as its impact on the environment.

关键词: MSWI bottom ash     Cu leaching     batch titration procedure     SEP    

Characterization of chlorine and heavy metals for the potential recycling of bottom ash from municipal

Boran WU, Dongyang WANG, Xiaoli CHAI, Fumitake TAKAHASHI, Takayuki SHIMAOKA

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0847-9

摘要: Industrial waste mixed with MSW is the main source of heavy metal in bottom ash. Chlorine content in bottom ash is controlled both by plastic and kitchen waste. Insoluble chlorine in Chinese MSWI bottom ash exists primarily as AlOCl. Bottom ash is an inevitable by-product from municipal solid waste (MSW) incineration plants. Recycling it as additives for cement production is a promising disposal method. However, the heavy metals and chlorine are the main limiting factors because of the potential environmental risks and corrosion of cement kilns. Therefore, investigating heavy metal and chlorine characteristics of bottom ash is the significant prerequisite of its reuse in cement industries. In this study, a correlative analysis was conducted to evaluate the effect of the MSW components and collection mode on the heavy metal and chlorine characteristics in bottom ash. The chemical speciation of insoluble chlorine was also investigated by synchrotron X-ray diffraction analysis. The results showed that industrial waste was the main source of heavy metals, especially Cr and Pb, in bottom ash. The higher contents of plastics and kitchen waste lead to the higher chlorine level (0.6 wt.%–0.7 wt.%) of the bottom ash. The insoluble chlorine in the MSW incineration bottom ash existed primarily as AlOCl, which was produced under the high temperature (1250℃) in incinerators.

关键词: Bottom ash     Chlorine     Heavy metals     Waste inputs     Synchrotron X-ray diffraction     AlOCl    

Leaching toxicity characteristics of municipal solid waste incineration bottom ash

Khamphe PHOUNGTHONG,Yi XIA,Hua ZHANG,Liming SHAO,Pinjing HE

《环境科学与工程前沿(英文)》 2016年 第10卷 第2期   页码 399-411 doi: 10.1007/s11783-015-0819-5

摘要: The continuously increasing production of municipal solid waste incineration bottom ash (MSWIBA) has promoted its utilization as construction material and raised environmental concern. The physico-chemical properties and leaching behavior of MSWIBA were studied, and ecotoxicological testing using a luminescent bacterium bioassay was performed to assess the ecological pollution risks associated with its leached constituents. The MSWIBA was leached by two types of leachants, H SO /HNO and HAc solution, at different liquid to solid ratios and contact times. The concentrations of heavy metals and anions in the leachates were analyzed. Multivariate statistical analyses, including principle component analysis, Pearson's correlation analysis and hierarchical cluster analysis, were used to evaluate the contributions of the constituents to the toxicity ( ) of the MSWIBA leachate. The statistical analyses of the ecotoxicological results showed that the Ba, Cr, Cu, Pb, F and total organic carbon (TOC) concentrations were closely correlated with the value, and these substances were the main contributors to the ecotoxicity of the MSWIBA leachate. In addition, the cluster of these variables indicated similar leaching behaviors. Overall, the research demonstrated that the ecotoxicological risks resulting from MSWIBA leaching could be assessed before its utilization, which provides crucial information for the adaptation of MSWIBA as alternative materials.

关键词: Municipal solid waste incineration     bottom ash     alternative material     leaching tests     toxicity     Vibrio qinghaiensis (Q67)    

BUEES: a bottom-up event extraction system

Xiao DING,Bing QIN,Ting LIU

《信息与电子工程前沿(英文)》 2015年 第16卷 第7期   页码 541-552 doi: 10.1631/FITEE.1400405

摘要: Traditional event extraction systems focus mainly on event type identification and event participant extraction based on pre-specified event type paradigms and manually annotated corpora. However, different domains have different event type paradigms. When transferring to a new domain, we have to build a new event type paradigm and annotate a new corpus from scratch. This kind of conventional event extraction system requires massive human effort, and hence prevents event extraction from being widely applicable. In this paper, we present BUEES, a bottom-up event extraction system, which extracts events from the web in a completely unsupervised way. The system automatically builds an event type paradigm in the input corpus, and then proceeds to extract a large number of instance patterns of these events. Subsequently, the system extracts event arguments according to these patterns. By conducting a series of experiments, we demonstrate the good performance of BUEES and compare it to a state-of-the-art Chinese event extraction system, i.e., a supervised event extraction system. Experimental results show that BUEES performs comparably (5% higher -measure in event type identification and 3% higher -measure in event argument extraction), but without any human effort.

关键词: Event extraction     Unsupervised learning     Bottom-up    

Analysis of catchment evapotranspiration at different scales using bottom-up and top-down approaches

Xiangyu XU, Dawen YANG,

《结构与土木工程前沿(英文)》 2010年 第4卷 第1期   页码 65-77 doi: 10.1007/s11709-010-0002-9

摘要: Physically-based hydrological models are used to predict catchment water balance through detailed simulation of hydrological processes at small temporal and spatial scales. However, annual catchment water balance can also be easily and simply predicted using lumped conceptual model. Comparison between physically-based hydrological models and lumped conceptual models can help us understand the dominant factors on catchment water balance at different scales. In this paper, a distributed physically-based hydrological model (i.e., bottom-up approach) and a simple water-energy balance model (i.e., top-down approach) are used to predict actual evapotranspiration in nine sub-catchments, and the whole basin of the Luan River in northern China. Both simulations give very close values of annual evapotranspiration and show the same complementary relationship between actual and potential evapotranspiration at annual time scale. From the analysis at different time scales through comparison of the top-down and the bottom-up methods, it is shown that the annual catchment evapotranspiration is controlled mainly by annual precipitation and potential evapotranspiration, and the variability of soil water and vegetation becomes more important at a smaller time scale in the study areas. It is also known that the relationship between potential and actual evapotranspiration shows a highly nonlinear relationship at the annual and catchment scale but can be simplified to a linear relationship at hourly temporal and hillslope scales, which is commonly used in the physically-based hydrological models.

关键词: catchment evapotranspiration     distributed hydrological model     water-energy balance model     top-down and bottom-up approaches    

Effect of fineness of ash on pozzolanic properties and acid resistance of sugarcane bagasse ash replaced

Shan E ALI; Rizwan AZAM; Muhammad Rizwan RIAZ; Mohamed ZAWAM

《结构与土木工程前沿(英文)》 2022年 第16卷 第10期   页码 1287-1300 doi: 10.1007/s11709-022-0872-7

摘要: This paper addresses the potential use of Sugar Cane Bagasse Ash (SCBA) as a pozzolanic material for partial cement replacement in concrete mixtures. Cement mortars containing SCBA having five different particle size distributions at a replacement rate of 20% by weight were used to study the chemical and physical pozzolanic properties of SCBA. The durability of SCBA replaced mortars was also evaluated. SCBA with 0% retained on sieve No. 325 was used to replace 20% by weight of cement and create mortar specimens that were subjected to sulfuric acid attack of varying concentrations (1%−3% by weight of water). The tested samples were observed to check visual distortion, mass loss, and compressive strength loss at 1, 7, 14, 28, and 56 d of acidic exposure, and the results were compared to those for the control sample, that was lime water cured, at the same ages. The SCBA sets were found to meet the requirements for pozzolan class N specified by ASTM C 618. Mortars containing SCBA with 0% or 15% retention produced better compressive strength than the control mortars after 28 d. Additionally, X-ray fluorescence and X-ray diffraction analysis showed that the SCBA had favorable chemical properties for a pozzolanic material. Furthermore, SCBA replaced samples at all ages showed improved resistance against acidic attack relative to that of the control mortars. Maximum deterioration was seen for 3% concentrated solution. This study’s findings demonstrated that SCBA with an appropriate fineness could be used as a pozzolanic material, consistently with ASTM C 618.

关键词: durability     cement replacement     sugarcane bagasse ash     fineness of ash     pozzolanic properties     mortar acid resistance    

Fresh and hardened properties of high-performance fiber-reinforced concrete containing fly ash and ricehusk ash: Influence of fiber type and content

Nguyen-Trong HO; Viet Quoc DANG; Minh-Hieu NGUYEN; Chao-Lung HWANG; Trong-Phuoc HUYNH

《结构与土木工程前沿(英文)》 2022年 第16卷 第12期   页码 1621-1632 doi: 10.1007/s11709-022-0884-3

摘要: Although fibers are used only infrequently as an additive in concrete in the construction industry, fiber-enhanced concrete is known to provide a wide range of advantages over conventional concrete. The main objective of this study was to investigate the influences of fiber type and content on the mechanical properties and durability of high-performance fiber-reinforced concrete (HPFRC) designed using a novel densified mixture design algorithm with fly ash and rice husk ash. Three types of fiber, including polypropylene (PP) fiber, steel fiber (SF), and hybrid fiber (HF), were considered. Based on the results, the inclusion of fibers decreased HPFRC flowability, regardless of fiber type. Although the compressive strength of HPFRC with 1.6% PP fiber content was 11.2% below that of the reference HPFRC specimen at 91 d of curing age, the 91-d compressive strengths of both SF and HF-enhanced HPFRC specimens were significantly better than that of the reference HPFRC specimen. Furthermore, the HPFRC specimens incorporating SF and HF both exhibited better splitting tensile and flexural strengths as well as less drying shrinkage than the HPFRC specimens incorporating PP fiber. However, the fiber-enhanced specimens, especially those with added SF, registered less surface electrical resistivity and greater vulnerability to chloride ion penetration than the reference HPFRC specimen.

关键词: high-performance fiber-reinforced concrete     fly ash     rice husk ash     durability     mechanical strength    

Effects of sulfur on variations in the chemical speciation of heavy metals from fly ash glass

《环境科学与工程前沿(英文)》 2023年 第17卷 第10期 doi: 10.1007/s11783-023-1728-7

摘要:

● A higher sulfur content reduced the curing rate of Cr in glass.

关键词: Dechlorinated fly ash     SO3     Heavy metal     Chemical speciation     Glass solidification    

Direct synthesis of carbon nanotubes on fly ash particles to produce carbon nanotubes/fly ash composites

Fangxian LI, Cheng ZHOU, Pengfei YANG, Beihan WANG, Jie HU, Jiangxiong WEI, Qijun YU

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1405-1414 doi: 10.1007/s11709-019-0564-0

摘要: Fly ash was used as catalytic support for carbon nanotubes (CNTs) growth by chemical vapor deposition (CVD) due to having ideal compositions (SiO , Al O , and Fe O ). In this paper, CNTs were synthesized on Ni catalyst/fly ash substrate using CVD method. The influence of parameters (e.g., reaction temperature and gas flow rate) on the carbon yield and structure of the resulting CNTs was on the carbon yield and structure of the resulting CNTs was investigated by thermo-gravimetric analyses, Scanning electron microscopy, and Raman spectroscopy analysis. The results indicated that the growth temperature controlling had a significant effect on the diameter of CNTs. And the proper acetylene and hydrogen flow rate would decrease in defect density and increase in yield of as-grown CNTs on fly ash. Finally, the amorphous carbon on the surface of as-grown CNTs were removed by heating in air. Experimental results showed that the hydrophobic of the annealed CNTs was weak due to introducing functional groups to the surface of CNTs.

关键词: carbon nanotubes     fly ash     chemical vapor deposition     parameters     purification    

Parametric study on seismic performance of self-centering reinforced concrete column with bottom-placed

《结构与土木工程前沿(英文)》   页码 1145-1162 doi: 10.1007/s11709-023-0945-2

摘要: To realize seismic-resilient reinforced concrete (RC) moment-resisting frame structures, a novel self-centering RC column with a rubber layer placed at the bottom (SRRC column) is proposed herein. For the column, the longitudinal reinforcement dissipates seismic energy, the rubber layer allows the rocking of the column, and the unbonded prestressed tendon enables self-centering capacity. A refined finite element model of the SRRC column is developed, the effectiveness of which is validated based on experimental results. Results show that the SRRC column exhibits stable energy dissipation capacity and no strength degradation; additionally, it can significantly reduce permanent residual deformation and mitigate damage to concrete. Extensive parametric studies pertaining to SRRC columns have been conducted to investigate the critical factors affecting their seismic performance.

关键词: seismic resilience     self-centering     rubber layer     flag-shaped hysteresis loop     parametric study    

Effect of circulating ash from CFB boilers on NO and N

Xiangsong HOU, Shi YANG, Junfu LU, Hai ZHANG, Guangxi YUE

《能源前沿(英文)》 2009年 第3卷 第2期   页码 241-246 doi: 10.1007/s11708-009-0006-0

摘要: NO and N O emissions from circulating fluidized bed (CFB) boilers are determined by their formation and destruction rates in the furnace. The effect of circulating ash from a CFB boiler on NO and N O emissions were investigated in a laboratory-scale fluidized bed reactor. The results show that the residue char in circulating ash and the CO generated from the char play an important role in NO reduction and N O formation; however, active components of circulating ash such as CaO, Fe O accelerate the decomposition of N O. Experiment was also conducted on a 75 t/h CFB boiler fueled with the mixture of anthracite and biomass. The lower residue carbon content of circulating ash in this experiment is lower; therefore, the reacting rate of NO deoxidize is limited. This result verified the conclusion of laboratory research.

关键词: CFB boiler     circulating ash     NO reduction     N2O thermal decomposition     biomass    

Assessing the potential of crop residue recycling in China and technology options based on a bottom-up

Lili QU,Tianzhu ZHANG,Wei LU

《环境科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 570-579 doi: 10.1007/s11783-013-0604-2

摘要: Crop residues are an important biomass, and are significant in the sustainable development of China. This paper uses the Grey-Markov modeling approach, the cost-benefit analysis method, and the constraint optimization method to establish the potential of crop residue recycling in China (CRRC) using a bottom-up analysis. Taking 2010 as the baseline year, the CRRC model is used to determine the quantity trends of crop residue resources, simulating the recycling potential and selecting key crop residue recycling technologies for operation between 2010 and 2030. The results illustrate that the total residue output from different crops will gradually increase to 1062 million tons in 2030. The proportion of crop residue for field burning is expected to decrease as a result of guidance and support from the government. Market mechanisms are also improving the development of the crop residue recycling industry. The economic benefit of crop residue recycling is expected to be worth 132 billion CNY in 2030 according to technology structure options. Key crop residue recycling technologies preferred such as liquefaction, amination, silo, co-firing straw power and composting will account for more than 85% of the total benefits.

关键词: China     crop residue     recycling potential     technology options    

Accelerated engineering properties of high and low volume fly ash concretes reinforced with glued steel

Vallarasu Manoharan SOUNTHARARAJAN, Dr. Anandan SIVAKUMAR

《结构与土木工程前沿(英文)》 2013年 第7卷 第4期   页码 429-445 doi: 10.1007/s11709-013-0226-6

摘要: The present study focuses on the improvement of pozzolanic reaction of fly ash particles with the cement hydration products. Low and high volume fly ash concrete mixtures were studied systematically with the addition of accelerating admixtures and accelerated curing of the concrete specimens in a steam chamber for 18 h at 75°C. Also, the reinforcing effects of glued steel fibers addition on the compressive and flexural performance of fly ash concrete were investigated. The test results indicated that the addition of accelerator improved the rate of hardening and the inclusion of steel fibers provided higher flexural performance. Also, it can be noted that the high volume fly ash (50%) addition in concrete showed a reduction in strength; however, the addition of accelerator has compensated the deceleration in strength gain. The proper selection of concrete ingredients, addition of accelerator and initial steam curing for 18 h showed better improvement on the engineering properties in fly ash concrete. A maximum increase (41.7%) in compressive strength of fly ash concrete around 52.90 MPa was noticed for 25% fly ash substitution and 1.5% steel fibers addition. Dynamic elastic modulus was also calculated in loaded concrete specimen using ultrasonic pulse velocity test and showed a good agreement with the experimental value.

关键词: fly ash     pozzolanic index     steam curing     superplasticizer     accelerator     steel fibres     elastic modulus    

Effects of seeding nucleation agent on geopolymerization process of fly-ash geopolymer

Lapyote PRASITTISOPIN, Issara SEREEWATTHANAWUT

《结构与土木工程前沿(英文)》 2018年 第12卷 第1期   页码 16-25 doi: 10.1007/s11709-016-0373-7

摘要: Geopolymer, an inorganic aluminosilicate material activated by alkaline medium solution, can perform as an inorganic adhesive. The geopolymer technology has a viability to substitute traditional concrete made of portland cement (PC) because replacing PC with fly ash leads to reduced carbon dioxide emissions from cement productions and reduced materials cost. Although fly ash geopolymer stimulates sustainability, it is slow geopolymerization reaction poses a challenge for construction technology in term of practicality. The development of increasing geopolymerization reaction rate of the geopolymer is needed. ?The purpose of this study is to evaluate seeding nucleation agents (NA) of fly ash geopolymer that can accelerate polymerization reactions such that the geopolymer can be widely used in the construction industry. Results from the present study indicate that the use of NA (i.e., Ca(OH) ) can be potentially used to increase geopolymerization reaction rate and improve performance characteristics of the fly ash geopolymer product.

关键词: fly ash     geopolymer     nucleation agent     portland cement replacement    

Service life prediction of fly ash concrete using an artificial neural network

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 793-805 doi: 10.1007/s11709-021-0717-9

摘要: Carbonation is one of the most aggressive phenomena affecting reinforced concrete structures and causing their degradation over time. Once reinforcement is altered by carbonation, the structure will no longer fulfill service requirements. For this purpose, the present work estimates the lifetime of fly ash concrete by developing a carbonation depth prediction model that uses an artificial neural network technique. A collection of 300 data points was made from experimental results available in the published literature. Backpropagation training of a three-layer perceptron was selected for the calculation of weights and biases of the network to reach the desired performance. Six parameters affecting carbonation were used as input neurons: binder content, fly ash substitution rate, water/binder ratio, CO2 concentration, relative humidity, and concrete age. Moreover, experimental validation carried out for the developed model shows that the artificial neural network has strong potential as a feasible tool to accurately predict the carbonation depth of fly ash concrete. Finally, a mathematical formula is proposed that can be used to successfully estimate the service life of fly ash concrete.

关键词: concrete     fly ash     carbonation     neural networks     experimental validation     service life    

标题 作者 时间 类型 操作

Investigation of Cu leaching from municipal solid waste incinerator bottom ash with a comprehensive approach

Jun YAO, Wenbing LI, Fangfang XIA, Jing WANG, Chengran FANG, Dongsheng SHEN

期刊论文

Characterization of chlorine and heavy metals for the potential recycling of bottom ash from municipal

Boran WU, Dongyang WANG, Xiaoli CHAI, Fumitake TAKAHASHI, Takayuki SHIMAOKA

期刊论文

Leaching toxicity characteristics of municipal solid waste incineration bottom ash

Khamphe PHOUNGTHONG,Yi XIA,Hua ZHANG,Liming SHAO,Pinjing HE

期刊论文

BUEES: a bottom-up event extraction system

Xiao DING,Bing QIN,Ting LIU

期刊论文

Analysis of catchment evapotranspiration at different scales using bottom-up and top-down approaches

Xiangyu XU, Dawen YANG,

期刊论文

Effect of fineness of ash on pozzolanic properties and acid resistance of sugarcane bagasse ash replaced

Shan E ALI; Rizwan AZAM; Muhammad Rizwan RIAZ; Mohamed ZAWAM

期刊论文

Fresh and hardened properties of high-performance fiber-reinforced concrete containing fly ash and ricehusk ash: Influence of fiber type and content

Nguyen-Trong HO; Viet Quoc DANG; Minh-Hieu NGUYEN; Chao-Lung HWANG; Trong-Phuoc HUYNH

期刊论文

Effects of sulfur on variations in the chemical speciation of heavy metals from fly ash glass

期刊论文

Direct synthesis of carbon nanotubes on fly ash particles to produce carbon nanotubes/fly ash composites

Fangxian LI, Cheng ZHOU, Pengfei YANG, Beihan WANG, Jie HU, Jiangxiong WEI, Qijun YU

期刊论文

Parametric study on seismic performance of self-centering reinforced concrete column with bottom-placed

期刊论文

Effect of circulating ash from CFB boilers on NO and N

Xiangsong HOU, Shi YANG, Junfu LU, Hai ZHANG, Guangxi YUE

期刊论文

Assessing the potential of crop residue recycling in China and technology options based on a bottom-up

Lili QU,Tianzhu ZHANG,Wei LU

期刊论文

Accelerated engineering properties of high and low volume fly ash concretes reinforced with glued steel

Vallarasu Manoharan SOUNTHARARAJAN, Dr. Anandan SIVAKUMAR

期刊论文

Effects of seeding nucleation agent on geopolymerization process of fly-ash geopolymer

Lapyote PRASITTISOPIN, Issara SEREEWATTHANAWUT

期刊论文

Service life prediction of fly ash concrete using an artificial neural network

期刊论文