铜基载氧体吸放氧性能的固定床实验研究

以机械混合法制备的铜基载氧体为研究对象,在固定床反应器中研究了反应温度、气体流量、惰性载体种类和惰性载体添加比例对铜基载氧体吸放氧性能的影响.实验结果表明:随着反应温度的升高载氧体的吸氧性能降低,但放氧性能提高;载氧体的吸放氧性能都随气体流量的增大而提高;对于制备的三种不同惰性载体的载氧体,其吸氧性能相差不大,放氧性能为Cu/Mg>Cu/Zr>Cu/Si.对于制备的三种不同惰性载体添加比例的载氧体,其吸放氧性能均随惰性载体添加比例的增大而提高.

(LPCCa)_2(MgNi)_(17)合金的吸放氢性能

研究了用部分Ca取代LPC(LPC为无钕镧镨铈混合稀土金属),同时用部分Ni取代Mg的(LPCCa)2(MgNi)17合金的吸放氢性能。比较了不同温度下,不同成分配比对合金贮氢性能的影响。其中,(LPC)1.9Ca0.1Mg15Ni2合金具有相对较低的放氢温度和较大的放氢量,在275℃的放氢量达3.43%(质量分数)。分析了(LPC)1.9Ca0.1Mg15Ni2的微观结构,同时对合金放氢温度降低的原因进行了讨论。

Research on the Impact of CeO2 -based Solid Solution Metal Oxide on Combustion Performance of Diesel Engine and Emissions

This paper mainly studies on the performance of high-speed diesel engines and emission reduction when the engine uses heavy oil mixed with nanometer-sized additives Ce0.9 Cu0.1 O2 and Ce0.9 Zr0.1 O2.During the test,Indiset 620 combustion analyzer made by AVL,was used to make a real-time survey on the cylinder pressure,the fuel ignition moment,and establish a relation between the change trend of temperature in cylinder and the crank angle.For the engine burning heavy oil and heavy oil mixed with additives,combustion analysis software Indicom and Concerto were used to analyze its combustion process and emission conditions.Experimental investigation shows that nano-sized complex oxide can improve the performance of diesel engine fueled with heavy oil,and reduce the emission of pollutants like NOx and CO,comparing it with the pure heavy oil.According to the consequences of this experiment,the additives improve the overall performance in the use of heavy oil.

Dynamic Changes,Regional Differences,and Influencing Factorsof CO_2 Emission Performance in China

This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO 2 emission performance.With the index,the authors have measured the CO 2 emission performance of 28 provinces and autonomous regions in China from 1996 to 2007;with the convergence theory and panel data regression model,the authors analyze the regional differences and the influencing factors.It is found that the performance of CO 2 emissions in China has been continuously improved mainly due to the technological progress,and the average improvement rate is 3.25%,with a cumulative improvement rate of 40.86%.In addition,the CO 2 emission performance varies across four regions.As a whole,the performance score of eastern China is the highest.The northeastern and central China has relatively lower performance scores,and the western China is relatively backward.The regional differences are decreasing,and the performance of CO 2 emissions is convergent.The influence of some factors on the performance of CO 2 emissions is significant,such as the level of economic development,the level of industrial structure,energy intensity,and ownership structure.The influence of some factors,such as opening-up to the outside world,on the performance of CO 2 emissions is not significant..

Application of waterborne acrylic emulsions in coated controlled release fertilizer using reacted layer technology

Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient release profiles of the coated fertilizers were determined. The results show that methyl silicone oil and methylsilanolate sodium could not improve water resistance performance and glass transition temperature Tgof coatings, while the firmness is enhanced. Aziridine crosslinker improves the water resistance performance, firmness and Tg. Incorporation of methyl silicone oil and aziridine crosslinker gives an excellent aqueous acrylic emulsion for coated controlled release fertilizer, with the 30-day cumulative nutrient release reduced to 16% and an estimated nutrient release duration over 190 days. Therefore, this waterborne coating is promising to meet the requirements for controlled release of nutrient and environmental protection.

HIGH EMISSION PERFORMANCE IMPREGNATED DISPENSER CATHODE

In order to obtain higher emission performance than that of a traditional M-type cathode, we have developed a new type impregnated dispenser cathode. The new cathode is impregnated with a new active substance with molar ratio of 26BaO·29SrO·8Sc2O3 ·7CaO·Al2O3 . This paper introduces the emission performance, surface active material, and work function of the new cathode. At 1100℃B , the DC current density and pulse current density are 30.6±1.0 A/cm2 and 171.6±2.8 A/cm2 , respectively, 2.1 and 5.4 times of that of an M-type cathode. The work function of the new cathode is 1.668± 0.002 eV. High concentration O-Al-Sc-Sr-Ba and O-Al-Sc-Ba are found in the pores and at pore edges, respectively. By comparing the emission performances and surface characteristics of as-polished and as-cleaned cathodes, it is proposed that, the emission around pore ends forms the major part of the total emission for the new cathodes.

Effect of exhaust gas recirculation and intake pre-heating on performance and emission characteristics of dual fuel engines at part loads

Achieving simultaneous reduction of NOx,CO and unburned hydrocarbon(UHC) emissions without compromising engine performance at part loads is the current focus of dual fuel engine research.The present work focuses on an experimental investigation conducted on a dual fuel(diesel-natural gas) engine to examine the simultaneous effect of inlet air pre-heating and exhaust gas recirculation(EGR) ratio on performance and emission characteristics at part loads.The use of EGR at high levels seems to be unable to improve the engine performance at part loads.However,it is shown that EGR combined with pre-heating of inlet air can slightly increase thermal efficiency,resulting in reduced levels of both unburned hydrocarbon and NOx emissions.CO and UHC emissions are reduced by 24% and 31%,respectively,The NOx emissions decrease by 21% because of the lower combustion temperature due to the much inert gas brought by EGR and decreased oxygen concentration in the cylinder.

UO2-BeO Composite Fuel Thermal Property and Performance Modeling

An enhanced thermal conductivity UO2-BeO composite nuclear fuel was studied. A methodology to generate ANSYS （an engineering simulation software） FEM （finite element method） thermal models of enhanced thermal conductivity oxide nuclear fuels was developed. The results showed significant increase in the fuel thermal conductivities and have good agreement with the measured ones. Thus BeO is one of the promising candidates for fabricating two-phase high thermal conductivity ceramic nuclear fuels with UO2. The reactor performance analysis showed that the decrease in centerline temperature was 250-350 K depending on different fabrication methods for the UO2-BeO composite fuel, and thus we can improve nuclear reactors＇ performance and safety, and high-level radioactive waste generation for the existing and next generation nuclear reactors.

Combustion of Renewable Biogas Fuels

Biogas fuel is a sustainable and renewable fuel produced from anaerobic digestion of organic matter. The biogas fuel is a flammable mixture of methane and carbon dioxide with low to medium calorific values. Biogas is an alternative to conventional fossil fuels and can be used for beating, transportation and power generation. CFD （computational fluid dynamic） analysis of the combustion performance and emissions of biogas fuel in gas turbine engines is presented in this study. The main objective of this study is to understand the impact of the variability in the biogas fuel compositions and lower heating values on the combustion process. Natural gas, biogas from anaerobic digester, landfill biogas, and natural gas/biogas mixture fuels combustion were investigated in this study. The CFD results show lower peak flame temperature and CO mole fractions inside the combustor and lower NOx emissions at the combustor exit for the biogas compared to natural gas fuel. The peak flame temperature decreases by 37% for the biogas landfill （COJCH4 = 0.89） and by 22% for the biogas anaerobic digester （CO2/CH4 = 0.54） compared to natural gas fuel combustion. The peak CO mole fraction inside the combustor decreases from 9.8 × 10-2 for natural gas fuel to 2.22 × 10-4 for biogas anaerobic digester and 1.32 × 10-7 for biogas landfill. The average NOx mole fraction at the combustor exit decreases from 1.13 × 10-5 for natural gas fuel to 0.40 × 10-6 for biogas anaerobic digester and 1.06 × 10-6 for biogas landfill. The presence of non-combustible constituents in the biogas reduces the temperature of the flame and consequently the NOx emissions.

Defect-related visible luminescence of ZnO nanorods annealed in oxygen ambient

ZnO nanorods prepared by a solution-phase method are annealed at different temperatures in oxygen ambient.The luminescence properties of the samples are investigated.In the same excitation condition,the photoluminescence(PL) spectra of all samples show an ultraviolet(UV) emission and a broad strong visible emission band.The asymmetric visible emis-sion band of annealed samples has a red-shift as the annealing temperature increasing from 200 ℃ to 600 ℃ and it can be deconvoluted into two subband emissions centered at 535 nm(green emission) and 611 nm(orange-red emission) by Gaussian-fitting analysis.Analyses of PL excitation(PLE) spectra and PL spectra at different excitation wavelengths reveal that the green emission and the orange-red emission have a uniform initial state,which can be attributed to the electron transition from Zn interstitial(Zni) to oxygen vacancy(Vo) and oxygen interstitial(Oi),respectively.