资源类型

期刊论文 108

年份

2023 3

2022 12

2021 18

2020 5

2019 9

2018 4

2017 13

2016 5

2015 4

2014 1

2013 4

2012 4

2011 4

2010 6

2009 1

2008 4

2007 3

2004 1

2002 1

2001 1

展开 ︾

关键词

Cu(In 2

Ga)Se2 2

粉煤灰 2

PDT 1

三峡工程 1

低温 1

先进制造 1

克努森蒸发源 1

凝结 1

分子层沉积 1

化学气相沉积 1

原子层沉积 1

变换气制碱 1

固体废弃物 1

土壤冲刷 1

坝下游河道冲刷 1

增加产量 1

库区泥沙淤积 1

悬移质 1

展开 ︾

检索范围:

排序: 展示方式:

Fault simulation of boiler heating surface ash deposition in a power plant system

Weiwei ZHANG, Huisheng ZHANG, Ming SU

《能源前沿(英文)》 2011年 第5卷 第4期   页码 435-443 doi: 10.1007/s11708-011-0162-x

摘要: The simulation model of a power generation system was developed based on EASY5 simulation platform. The performances of the power plant under the conditions of the furnace slagging and ash deposition of the heating surfaces in the boiler were simulated. The results show that the simulation model can reasonably reflect the characteristics of the power plant when each component is under fault conditions. Through fault simulation, the change of the performance parameters can be obtained, which can be used in fault diagnosis system as the diagnosis criterion for expert system.

关键词: boiler     slagging     ash deposition     fault simulation    

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    

Compositional and structural study of ash deposits spatially distributed in superheaters of a large biomass-fired

Yishu XU, Xiaowei LIU, Jiuxin QI, Tianpeng ZHANG, Minghou XU, Fangfang FEI, Dingqing LI

《能源前沿(英文)》 2021年 第15卷 第2期   页码 449-459 doi: 10.1007/s11708-021-0734-3

摘要: Recognizing the nature and formation progress of the ash deposits is essential to resolve the deposition problem hindering the wide application of large-scale biomass-fired boilers. Therefore, the ash deposits in the superheaters of a 220 t/h biomass-fired CFB boiler were studied, including the platen (PS), the high-temperature (HTS), the upper and the lower low-temperature superheaters (LTS). The results showed that the deposits in the PSs and HTSs were thin (several millimeters) and compact, consisting of a yellow outer layer and snow-white inner layer near the tube surface. The deposits in the upper LTS appeared to be toughly sintered ceramic, while those in the lower LTS were composed of dispersive coarse ash particles with an unsintered surface. Detailed characterization of the cross-section and the initial layers in the deposits revealed that the dominating compositions in both the PSs and the HTSs were Cl and K (approximately 70%) in the form of KCl. Interestingly, the cross-section of the deposition in the upper LTS exhibited a unique lamellar structure with a major composition of Ca and S. The contents of Ca and Si increased from approximately 10% to approximately 60% in the deposits from the high temperature surfaces to the low temperature ones. It was concluded that the vaporized mineral matter such as KCl played the most important role in the deposition progress in the PS and the HTS. In addition, although the condensation of KCl in the LTSs also happened, the deposition of ash particles played a more important role.

关键词: ash deposition     biomass combustion     circulating fluidized bed     initial layer     structure analysis    

Scaling up of cluster beam deposition technology for catalysis application

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1360-1379 doi: 10.1007/s11705-021-2101-7

摘要: Many research works have demonstrated that the combination of atomically precise cluster deposition and theoretical calculations is able to address fundamental aspects of size-effects, cluster-support interactions, and reaction mechanisms of cluster materials. Although the wet chemistry method has been widely used to synthesize nanoparticles, the gas-phase synthesis and size-selected strategy was the only method to prepare supported metal clusters with precise numbers of atoms for a long time. However, the low throughput of the physical synthesis method has severely constrained its wider adoption for catalysis applications. In this review, we introduce the latest progress on three types of cluster source which have the most promising potential for scale-up, including sputtering gas aggregation source, pulsed microplasma cluster source, and matrix assembly cluster source. While the sputtering gas aggregation source is leading ahead with a production rate of ~20 mg·h–1, the pulsed microplasma source has the smallest physical dimensions which makes it possible to compact multiple such devices into a small volume for multiplied production rate. The matrix assembly source has the shortest development history, but already show an impressive deposition rate of ~10 mg·h–1. At the end of the review, the possible routes for further throughput scale-up are envisaged.

关键词: nanoparticle     cluster     cluster beam deposition     magnetron sputtering     heterogeneous catalysis    

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    

Effect of carbon deposition over carbonaceous catalysts on CH

Yongfa ZHANG, Meng ZHANG, Guojie ZHANG, Huirong ZHANG

《化学科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 481-485 doi: 10.1007/s11705-010-0523-8

摘要: An investigation was made using a continuous fixed bed reactor to understand the influence of carbon deposition obtained under different conditions on CH -CO reforming. Thermogravimetry (TG) and X-ray diffraction (XRD) were employed to study the characteristics of carbon deposition. It was found that the carbonaceous catalyst is an efficient catalyst in methane decomposition and CH -CO reforming. The trend of methane decomposition at lower temperatures is similar to that at higher temperatures. The methane conversion is high during the initial of stage of the reaction, and then decays to a relatively fixed value after about 30 min. With temperature increase, the methane decomposition rate increases quickly. The reaction temperature has significant influence on methane decomposition, whereas the carbon deposition does not affect methane decomposition significantly. Different types of carbon deposition were formed at different methane decomposition reaction temperatures. The carbon deposition Type I generated at 900°C has a minor effect on CH -CO reforming and it easily reacts with carbon dioxide, but the carbon deposition Type II generated at 1000°C and 1100°C clearly inhibits CH -CO reforming and it is difficult to react with carbon dioxide. The results of XRD showed that some graphite structures were found in carbon deposition Type II.

关键词: carbon deposition     carbonaceous catalyst     CH4-CO2 reforming    

Influence mechanism of dynamic and static liquid bridge forces on particle deposition behaviors in solar

Xueqing LIU, Xiaodong ZHAO, Luyi LU, Jianlan LI

《能源前沿(英文)》 2021年 第15卷 第2期   页码 499-512 doi: 10.1007/s11708-021-0742-3

摘要: Solar energy is one of the most promising forms of renewable energy for solving the energy crisis and environmental problems. Dust deposition on photovoltaic mirrors has a serious negative impact on the photoelectric conversion efficiency of solar power stations. In this paper, the influence mechanism of the dynamic and static liquid bridge forces on particle deposition behaviors on solar photovoltaic mirrors is investigated. In addition, the expression and physical meaning of the particle critical separation velocity are proposed. The research results show that the static liquid bridge force can be the primary deposition force causing dust particles to adhere to photovoltaic mirrors. However, the dynamic liquid bridge force can act as a resistance force for the particle motion process and even make dust particles roll along and finally stay on the mirror. The contact force is the primary separation force that causes dust particles to flow away from the mirror. Whether dust particles adhere to the mirror depends on the relative size of the deposition and separating forces. The particle critical separation velocity describes the relative size of the collision-rebound effect and mirror adhesion effect and is expressed in Eq. (16). These research findings can provide theoretical guidance for mirror cleaning methods in the operation process of photovoltaic mirrors.

关键词: dust deposition     discrete element method (DEM)     photovoltaic mirrors     solar energy    

ECOLOGICAL EFFECTS OF NITROGEN DEPOSITION ON URBAN FORESTS: AN OVERVIEW

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 445-456 doi: 10.15302/J-FASE-2021429

摘要:

● Patterns and effects of N deposition on urban forests are reviewed.

关键词: biodiversity     carbon sequestration     nitrogen deposition     nutrient imbalance     soil acidification     urban forest    

Effect of oil shale semi-coke on deposit mineralogy and morphology in the flue path of a CFB burning Zhundong lignite

Zhuo LIU, Jianbo LI, Mingming ZHU, Xiaofeng LU, Zhezi ZHANG, Dongke ZHANG

《能源前沿(英文)》 2021年 第15卷 第1期   页码 26-37 doi: 10.1007/s11708-020-0668-1

摘要: The effect of oil shale semi-coke (SC) on the mineralogy and morphology of the ash deposited on probes situated in the flue path of a circulating fluidized bed (CFB) which burns Zhundong lignite (ZD) was investigated. 10 wt% or 20 wt% SC was added to ZD, which were then combusted in the CFB furnace at 950°C. Two probes with vertical and horizontal orientations were installed in the flue duct to simulate ash deposition. Both windward and leeward ash deposits on probes (P W, P L, P W and P L) were analyzed by using a scanning electron microscopy with energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), an inductively coupled plasma optical emission spectrometry ICP-OES, and a particle size analyzer. When ZD was burned alone, the P W deposit was comprised of agglomerates (<30 m) enriched in CaSO and Na SiO , incurring significant sintering. The P L and P W deposits, however, were of both discrete and agglomerated particles in similar mineral phases but with coarser sizes. The P L deposit was mainly fine ash particles where Na SiO and Na SO were absent. As SC was added, the agglomerates in both P W and P L decreased. Moreover, SiO and Ca/Na aluminosilicates dominated the mineral phases whereas Na SiO and Na SO disappeared, showing a decrease in deposit stickiness. Likewise, the P W deposit was found less spread on the probe, decreasing its deposition propensity. Na-bearing minerals turned into (Na, K)(Si Al)O and (Ca, Na)(Si, Al) O in the P W deposit. Moreover, Na in the deposits decreased from 32 mg/g to less than 15 mg/g as SC presented. The addition of SC would therefore help alleviate the propensity of ash deposition in the flue path in the CFB combustion of ZD.

关键词: ash deposition     circulating fluidized bed (CFB)     mineral transformation     oil shale semi-coke (SC)     Zhundong lignite (ZD)    

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    

Influence of phosphate on deposition and detachment of TiO

Zhan Wang, Chongyang Shen, Yichun Du, Yulong Zhang, Baoguo Li

《环境科学与工程前沿(英文)》 2019年 第13卷 第5期 doi: 10.1007/s11783-019-1163-y

摘要: We examined influence of phosphate on transport of TiO2 NPs in soil. Deposition was reduced at higher pH and by adsorption of phosphate in soil. Release was more for NPs initially deposited at higher pH. Release was more for NPs initially deposited in the presence of phosphate. Surface roughness and charge heterogeneity play a role in the deposition/ release. The widespread use of TiO2 nanoparticles (NPs) makes inevitable their release into the soil. Phosphate is also widespread within soil, and is likely copresent with TiO2 NPs. However, the influence of phosphate on deposition/release— and thereby on transport— of TiO2 NPs in soil is yet to be elucidated. In this study we conducted saturated column experiments to systematically examine the transport of TiO2 NPs in soil amended with phosphate at different ionic strengths (ISs) (1, 10, 100 mmol/L NaCl) and pHs (4 and 9). Results show that the deposition of TiO2 NPs decreased with decreasing IS, increasing pH, and when soil absorbed phosphate. These observations are qualitatively in agreement with Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy calculations, because the repulsive energy barrier is larger and secondary minimum depth is smaller at a lower IS, higher pH, and in the presence of phosphate. Accordingly, both primary- and secondary-minimum deposition were inhibited. Interestingly, although the deposition was less at higher pH and in the presence of phosphate, the subsequent spontaneous detachment and detachment by reduction of solution IS in these cases were greater. In addition, the presence of phosphate in the solution can cause a small quantity of attached TiO2 NPs to detach, even without perturbations of physical and chemical conditions. Our study was the first to investigate the influence of phosphate on detachment of TiO2 NPs and the results have important implication for accurate prediction of fate and transport of TiO2 NPs in subsurface environments.

关键词: Phosphate     TiO2 nanoparticles     Transport     Soil     Deposition     Detachment    

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    

标题 作者 时间 类型 操作

Fault simulation of boiler heating surface ash deposition in a power plant system

Weiwei ZHANG, Huisheng ZHANG, Ming SU

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

Compositional and structural study of ash deposits spatially distributed in superheaters of a large biomass-fired

Yishu XU, Xiaowei LIU, Jiuxin QI, Tianpeng ZHANG, Minghou XU, Fangfang FEI, Dingqing LI

期刊论文

Scaling up of cluster beam deposition technology for catalysis application

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

Effect of carbon deposition over carbonaceous catalysts on CH

Yongfa ZHANG, Meng ZHANG, Guojie ZHANG, Huirong ZHANG

期刊论文

Influence mechanism of dynamic and static liquid bridge forces on particle deposition behaviors in solar

Xueqing LIU, Xiaodong ZHAO, Luyi LU, Jianlan LI

期刊论文

ECOLOGICAL EFFECTS OF NITROGEN DEPOSITION ON URBAN FORESTS: AN OVERVIEW

期刊论文

Effect of oil shale semi-coke on deposit mineralogy and morphology in the flue path of a CFB burning Zhundong lignite

Zhuo LIU, Jianbo LI, Mingming ZHU, Xiaofeng LU, Zhezi ZHANG, Dongke ZHANG

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

Influence of phosphate on deposition and detachment of TiO

Zhan Wang, Chongyang Shen, Yichun Du, Yulong Zhang, Baoguo Li

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