检索结果-南通市图书馆

Detailed influences of ethanol as fuel additive on combustion chemistry of premixed fuel-rich ethylene flames

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第10期58卷 1696-1704页

作者： liu dong School of Energy and Power Engineering Nanjing University of Science and Technology

To better understand potential pollutant formations during combustion of conventional hydrocarbon fuels blended with oxygenated fuels, detailed influences of ethanol as fuel additive on small polycyclic aromatic hydrocarbons(PAHs) precursors, aldehydes, ketene and other important intermediate species in premixed fuel-rich low-pressure ethylene flames are distinguished among dilution, thermal and chemical effects of additives. Dominant effects of ethanol addition on each species are underlined respectively. Ethylene oxidation process is delayed when ethylene is substituted by ethanol. The influence of ethanol dilution and thermal effects on ethylene consumption are larger than chemical effects. CO mole fractions slightly decrease mainly as a result of dilution and thermal effects of added ethanol. The reductions in small PAHs precursors(acetylene and propargyl) are attributed to dilution and thermal effects of ethanol addition instead of chemical effects. The ethanol chemical effects promote formations of hazardous pollutants formaldehyde and acetaldehyde, and especially are responsible for the significant increase of acetaldehyde. C2H6, C4H2 and C4H4 mole fractions decrease in a similar way with acetylene and propargyl as ethanol is added. Ethanol used here only serves as a prototype of oxygenated additive, and identification method in this work is more universal which can be easily extended for analyzing other fuel blends of hydrocarbon and oxygenated fuels.

关键词： ethylene flame ethanol addition chemical effect pollutant formations identification method

Combustion characteristics of nanofluid fuels in a half-opening slot tube

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2017年第7期60卷 1075-1087页

作者： liu GuanNan liu dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science&TechnologyNanjing 210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China

Combustion characteristics of nanofluid fuels containing aluminum nanoparticles were investigated in half-opening slot tubes from the fundamental view. The effects of particle loading rates(0.25% and 2.5% by weight), type of base fuels(ethanol and butanol),and fuel flow rates(0.2, 0.6, and 1 mL/min) were studied in details. The combustion characteristics of the nanofluid fuels and pure based fuels were also examined to provide a comparison. Flame was unstable with reignition, stable state, nearly extinguishment repeatedly at low flow rate. At medium flow rate, flame height was increased and flame tended to be stable. At high flow rate,flame became unstable and was disturbed by the droplet forming and dripping significantly. Al atoms inside the oxide layer should be melted before the particles combustion, while Al oxide layer should be melted before the particles aggregates combustion. The effects of particles on the combustion characteristics, especially on the evaporation rate of base fuel, were discussed. The reasons for various combustion phenomena of nanofluid fuels were given, which can provide the useful guidance for the experimental research and practical applications of nanofluid fuels.

关键词： nanofluid fuel combustion aluminum ethanol butanol

Root developmental responses to phosphorus nutrition

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2021年第6期63卷 1065-1090页

作者： dong liu MOE Key Laboratory of Bioinformatics School of Life SciencesCenter for Plant BiologyTsinghua UniversityBeijing 100084China

Phosphorus is an essential macronutrient for plant growth and development. Root system architecture(RSA) affects a plant's ability to obtain phosphate, the major form of phosphorus that plants uptake. In this review, I first consider the relationship between RSA and plant phosphorusacquisition efficiency, describe how external phosphorus conditions both induce and impose changes in the RSA of major crops and of the model plant Arabidopsis, and discuss whether shoot phosphorus status affects RSA and whether there is a universal root developmental response across all plant species. I then summarize the current understanding of the molecular mechanisms governing root developmental responses to phosphorus deficiency. I also explore the possible reasons for the inconsistent results reported by different research groups and comment on the relevance of some studies performed under laboratory conditions to what occurs in natural environments.

关键词： developmental responses molecular mechanism phosphorus-acquisition efficiency phosphorus nutrition root system architecture

Energy conversion and ignition of iron nanoparticles by flash

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2017年第12期60卷 1878-1884页

作者： liu YanXiong liu dong liu GuanNan MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science & Technology Nanjing 210094 China Advanced Combustion Laboratory School of Energy and Power Engineering Nanjing University of Science and Technology Nanjing 210094 China

In the present study, Fe nanoparticles(NPs) can ignite when exposed to a conventional camera flash. The ignition process of Fe NPs was composed of the initial ignition stage with the maximum temperature level of 2000 K and the burning stage with temperature level of 800 K. The microstructure characterization indicated Fe NPs were oxidized to Fe_2 O_3 via the exposure-melt *** was found that more particle numbers per unit area can lead to lower minimum ignition energy which may be caused by the enhancement light energy absorption. The light energy absorbed from the flash was influenced by wavelengths but the conversion of Fe was only related to the packing mass.

关键词： flash ignition Fe nanoparticles minimum ignition energy

Formation and characteristics of soot from pyrolysis of ethylene blended with furan fuels

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2021年第3期64卷 585-598页

作者： ZHANG LiJie liu dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China

As two renewable oxygenated biofuels,2,5-dimethylfuran and 2-methylfuran(DMF and MF)have been considered to be two of the most potential fuels in the future due to the development of the second-generation biosynthetic *** atmosphere pyrolysis experiments with 0%,25%,50%,75%and 100%replacement of ethylene by DMF/MF at 1173 and 1273 K were *** soot samples were characterized by high resolution transmission electron microscopy(HRTEM)and thermogravimetric analysis(TGA)to acquire their internal structure and oxidation *** showed that soot mass was positively related with DMF addition ratios and the reaction *** production was also enhanced when the MF addition ratio gradually increased from 0%to 75%.The influences of DMF addition can promote soot formation more obviously than *** showed a more significant influence on soot morphology than fuel types and DMF/MF addition *** a fixed addition ratio of DMF/MF,soot showed liquid-like substances at 1173 *** 1273 K,approximately round particles formed and linked together in ***,at 1273 K,the aggregates obtained by adding MF contained more single particles,longer carbon chains,and larger projection area compared with the aggregates by adding same *** nanostructures,as the addition ratios of DMF/MF increased,as well as the reaction temperature improved,the fringe length of the carbon layer increased,the average fringe tortuosity decreased,and the stacking arrangement of soot became more orderly,the soot oxidation reactivity was *** a same addition ratio and reaction temperature,soot obtained by adding DMF possessed slightly longer fringe length,smaller fringe tortuosity and lower oxidation reactivity than those of the soot obtained by adding *** correlation between fringe parameters and soot oxidation reactivity was *** more ordered soot nanostructure,the longer fringe length,and the smaller fringe tortuosity could m

关键词： soot pyrolysis furan fuels nanostructure reactivity

Coupled chemical effects of carbon dioxide and hydrogen additions on premixed lean dimethyl ether flames

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2017年第1期60卷 102-115页

作者： PAN Wei liu dong School of Energy and Power Engineering Nanjing University of Science and Technology Nanjing 210094 China

Kinetic analysis of coupled effects of CO2 and H2 additions on laminar lean premixed dimethyl ether flames is performed at atmospheric pressure. The coupled effects of H2/CO2 additions on major species, intermediate stable species and radicals are discussed and analyzed in detail. The dilution, thermal and chemical effects of H2 and CO2 are separated and identified. The results show that H2 addition can slightly mitigate the CO2 chemical effects on decreasing the temperatures, H radical concen- tration, acetylene mole fraction and formaldehyde concentration. After CO2 is added, the H2 chemical effects on increasing the temperatures are enhanced. DME oxidation is promoted by the H2 chemical effects, which is further strengthened by the CO2 addition. Moreover, CO2 addition can reduce the H2 chemical effects on increasing the H radical mole fraction, but strengthen the H2 chemical effects on increasing the production of HO2 and C2H2. CH2O formation can be promoted by the H2 chemical effects, which is enhanced by the CO2 addition. In actually, the H2/CO2 coupled chemical effects almost have no obvious in- fluence on the temperatures and HO2 mole fraction. DME consumption is delayed by the H2/CO2 coupled chemical effects. Furthermore, the H2/CO2 coupled chemical effects can decrease the H radical mole fraction, CH4 concentration, C2H2 mole fraction, CH2O concentration and CHaCHO mole fraction, but increase the CO concentration.

关键词： dimethyl ether flame H2/CO2 addition coupled effects kinetic analysis

Reconstruction model for temperature and concentration profiles of soot and metal-oxide nanoparticles in a nanofluid fuel flame by using a CCD camera

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第5期27卷 334-343页

作者： Guannan liu dong liu MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanfing University of Science and TechnologyNanjing 210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China

This paper presents a numerical study on the simultaneous reconstruction of temperature and volume fraction fields of soot and metal-oxide nanoparticles in an axisymmetric nanofluid fuel sooting flame based on the radiative energy images captured by a charge-coupled device(CCD)*** least squares QR decomposition method was introduced to deal with the reconstruction inverse *** effects of ray numbers and measurement errors on the reconstruction accuracy were *** was found that the reconstruction accuracies for volume fraction fields of soot and metaloxide nanoparticles were easily affected by the measurement errors for radiation intensity,whereas only the metal-oxide volume fraction field reconstruction was more sensitive to the measurement error for the volume fraction ratio of metaloxide nanoparticles to *** results show that the temperature,soot volume fraction,and metal-oxide nanoparticles volume fraction fields can be simultaneously and accurately retrieved for exact and noisy data using a single CCD camera.

关键词： simultaneous reconstruction temperature distribution soot and metal-oxide volume fraction nanofluid fuel flame

The pseudocapacitance mechanism of graphene/CoAl LDH and its derivatives:Are all the modifications beneficial?

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第1期30卷 218-227,I0007页

作者： Chuan Jing Xu dong liu Kailin Li Xiaoying liu Biqin dong Fan dong Yuxin Zhang State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Research Centre of Laser Fusion China Academy of Engineering PhysicsMianyang 621900SichuanChina Engineering Research Center for Waste Oil Recovery Technology and Equipment of Ministry of Education Chongqing Key Laboratory of Catalysis and New Environmental MaterialsCollege of Environment and ResourcesChongqing Technology and Business UniversityChongqing 400067China Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering Shenzhen UniversityShenzhen 518060GuangdongChina Research Center for Environmental Science&Technology Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731SichuanChina

Cobalt-Aluminum layered double hydroxide(CoAl LDH) is a hopeful electrode material due to the advantage of easy modifiability for preparing LDH-based ***,there is short of modification methods to prepare the Co-based derivatives from CoAl LDH and also short of an intuitive perspective to analyze the pseudocapacitance mechanism of CoAl LDH and its ***,Graphene/CoAl LDH and its derivatives including Graphene/CoS,Graphene/CoS-1,Graphene/CoOOH,Graphene/CoP were prepared by reasonably using alkali etching treatment,sulfofication and *** specific capacitance of Graphene/CoAl LDH,Graphene/CoS,Graphene/CoS-1,Graphene/CoOOH,Graphene/CoP at1 A g^(-1) are 260.7,371.3,440.8,61.4 and 122.2 F g^(-1),*** pseudocapacitance mechanism of Graphene/CoAl LDH and its derivatives was *** to the positive effect of sulfofication on the electrical conductivity of GO and cobalt sulfide,the Graphene/CoS and Graphene/CoS-1 exhibit the optimal electrochemical performance and superior rate *** addition,due to the repulsion effect between Graphene and OH-,the Graphene/CoAl LDH exhibits optimal cycling stability of 224.1% capacitance retention after 20000 ***,the reason of terrible specific capacitance of Graphene/CoOOH is that the presence of H bond in interlayer of CoOOH inhibits the interaction between Co3+ and ***,not all modifications will increase the specific capacitance of the electrode ***,this work provides us with a detailed analysis of the electrochemical mechanism and correlation of CoAl LDH and its derivatives from the perspective of crystal structure and composition.

关键词： CoAl LDH and its derivates Modification Pseudocapacitance mechanism Alkali etching treatment Sulfofication Phosphorization

Phase stability and magnetic performance of nanocrystalline Sm-Co supersaturated solid solution

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2018年第1期61卷 129-134页

作者： liu dong liu XueMei liu GuoQuan SONG XiaoYan College of Materials Science and Engineering Key Laboratory of Advanced Functional Materials Ministry of Education of China Beijing University of Technology Beijing 100124 China Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing 100083 China

A new type of Sm-Co supersaturated solid solution has been developed with a stabilized TbCuT-type structure. The high-Co single phases were stabilized in a wide temperature range in the prepared SmCo9.8-xSix （x=0-0.9） alloys by concurrent nanos- tructuring and Si-doping. The significant enhancement of the coercivity and remanence of the new type supersaturated solid solution are attributed to the effective pinning of the ultrafine nanograin boundaries and the high magnetocrystalline anisotropy of the solid solution. It was proposed that the high-temperature magnetic properties of the Sm-Co supersaturated solid solution depend strongly on the phase stability.

关键词： supersaturated solid solution nanoerystalline doping phase stability