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Synthesis of a chabazite-supported copper catalyst with full mesopores for selective catalytic reduction of nitrogen oxides at low temperature 被引量:9
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作者 刘计省 刘坚 +4 位作者 赵震 宋卫余 韦岳长 段爱军 姜桂元 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第5期750-759,共10页
A series of meso‐microporous copper‐supporting chabazite molecular sieve(CuSAPO‐34) catalysts with excellent performance in low‐temperature ammonia selective catalytic reduction(NH3‐SCR)have been synthesized ... A series of meso‐microporous copper‐supporting chabazite molecular sieve(CuSAPO‐34) catalysts with excellent performance in low‐temperature ammonia selective catalytic reduction(NH3‐SCR)have been synthesized via a one‐pot hydrothermal crystallization method. The physicochemical properties of the catalysts were characterized by scanning electron microscopy, transmission electron microscopy, N2 adsorption‐desorption measurements, X‐ray diffraction, 27 Al magic angle spinning nuclear magnetic resonance, diffuse reflectance ultraviolet‐visible spectroscopy, inductively coupled plasma‐atomic emission spectroscopy, X‐ray photoelectron spectroscopy, temperature‐programmed reduction measurements, and electron paramagnetic resonance analysis. The formation of micro‐mesopores in the Cu‐SAPO‐34 catalysts decreases diffusion resistance and greatly improves the accessibility of reactants to catalytic active sites. The main active sites for NH3‐SCR reaction are the isolated Cu^2+ species displaced into the ellipsoidal cavity of the Cu‐SAPO‐34 catalysts. 展开更多
关键词 One-pot synthesis Meso-microporous Cu-SAPO-34 Low temperature Selective catalytic reduction nitrogen oxides
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Direct and Indirect Applications of Dielectric Barrier Discharge Plasma to Catalytic Reduction of Nitrogen Oxides from Exhaust Gas 被引量:7
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作者 YOUNG Sun Mok 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第2期207-212,共6页
Dielectric barrier discharge (DBD) plasma was utilized to oxidize NO contained in the exhaust gas to NO2, ultimately improve the selective catalytic reduction of nitrogen oxides (NOx). In the one case, DBD was cre... Dielectric barrier discharge (DBD) plasma was utilized to oxidize NO contained in the exhaust gas to NO2, ultimately improve the selective catalytic reduction of nitrogen oxides (NOx). In the one case, DBD was created directly in the exhaust gas (direct application), and in the an other case, ozone produced by DBD was injected into the exhaust gas (indirect application). A comparative study between such direct and indirect applications of DBD plasma was made in terms of the NOx removal efficiency and the energy consumption. The NO2 content in the exhaust gas was changed by the voltage applied to the DBD device (for direct application) or by the amount of ozone added to the exhaust gas (for indirect application). In both cases, NO was easily oxidized to NO2, and the change in NO2 content largely affected the NOx removal performance of the catalytic reactor placed downstream, where both NO and NO2 were reduced to N2 in the presence of ammonia as the reducing agent. The experiments were primarily concerned with the effect of reaction temperature on the catalytic NOx reduction at various NO2 contents. The direct and indirect applications of DBD were found to remarkably improve the catalytic NOx reduction, especially at low temperatures. 展开更多
关键词 dielectric barrier discharge OZONE catalytic reduction nitrogen oxides
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Catalyst-Packed Non-Thermal Plasma Reactor for Removal of Nitrogen Oxides 被引量:4
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作者 V.Ravi YoungSunMok +1 位作者 B.S.Rajanikanth Ho-ChulKang 《Plasma Science and Technology》 SCIE EI CAS CSCD 2003年第1期1603-1608,共6页
A single-stage plasma-catalytic reactor in which catalytic materials werepacked was used to remove nitrogen oxides. The packing material was scoria being made of variousmetal oxides including Al_2O_3, MgO, TiO_2, etc.... A single-stage plasma-catalytic reactor in which catalytic materials werepacked was used to remove nitrogen oxides. The packing material was scoria being made of variousmetal oxides including Al_2O_3, MgO, TiO_2, etc. Scoria was able to act not only as dielectricpellets but also as a catalyst in the presence of reducing agent such as ethylene and ammonia.Without plasma discharge, scoria did not work well as a catalyst in the temperature range of 100 ℃to 200 ℃, showing less than 10% of NOx removal efficiency. When plasma is produced inside thereactor, the NOx removal efficiency could be increased to 60% in this temperature range. 展开更多
关键词 plasma CATALYST SCORIA nitrogen oxides REMOVAL
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A New Approach for Removal of Nitrogen Oxides from Synthetic Gas-streams under High Concentration of Oxygen in Biofilters 被引量:3
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作者 ShaoBinHUANG JuGuangZHANG HePingHU YueSITU 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第4期505-508,共4页
The potential of using denitrifying and nitrifying concurrent biofilters for the removal of nitrogen oxides from synthetic gas streams was studied under the condition of high oxygen concentration. It was found that ... The potential of using denitrifying and nitrifying concurrent biofilters for the removal of nitrogen oxides from synthetic gas streams was studied under the condition of high oxygen concentration. It was found that more than 85% of nitric oxide was removed from synthetic combustion gas-streams which contained 20% oxygen and 350 μL/L NO, with a residence time of 60 seconds. In the process, it was found that the existing of oxygen showed no evident negative effect on the efficiency of nitrogen removal. 展开更多
关键词 BIOFILTER nitrogen oxides nitrification denitrification aerobic.
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Removal of Nitrogen Oxides in Diesel Engine Exhaust by Plasma Assisted Molecular Sieves 被引量:3
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作者 B S Rajanikanth, V RaviDept. of High Voltage Engineering, Indian Institute of Science, Bangalore 560012,INDIA 《Plasma Science and Technology》 SCIE EI CAS CSCD 2002年第4期1399-1406,共8页
This paper reports the studies conducted on removal of oxides ofnitrogen (NOx) from diesel engine exhaust using electrical dischargeplasma combined with adsorbing materials such as molecular sieves.This study is being... This paper reports the studies conducted on removal of oxides ofnitrogen (NOx) from diesel engine exhaust using electrical dischargeplasma combined with adsorbing materials such as molecular sieves.This study is being reported for the first time. The exhaust is takenfrom a diesel engine of 6 kW under no load conditions. Thecharacteristic behavior of a pulse energized dielectric barrierdischarge reactor in the diesel exhaust treatment is reported. TheNOx removal was not significant (36/100) when the reactor without anypacking was used. 展开更多
关键词 diesel engine exhaust nitrogen oxides REMOVAL electrical discharge plasma
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STUDIES ON TBP-NO_x——A NEW OXIDIZING AGENT PREPARED FROM NITROGEN OXIDES 被引量:1
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作者 Shen Shong ZHANG Ren Zhong QIAO +1 位作者 Qing Zhi ZHANG Fu Gui LU 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第11期877-878,共2页
Nitrogen oxides(NO_2 and NO)are absorbed by tributyl phosphorate(TBP)to fom a new complex mixture of TBP-NO_x. which is used as a selective oddizing agent to oxidize benzylalcohols to corresponding sldehydes or ketone... Nitrogen oxides(NO_2 and NO)are absorbed by tributyl phosphorate(TBP)to fom a new complex mixture of TBP-NO_x. which is used as a selective oddizing agent to oxidize benzylalcohols to corresponding sldehydes or ketones In high yield. In the reaction process, nitrogen oxides are llberated mildly and mainly reduced to nitrogen, while tributyl phosphorate is recovered end recycled. 展开更多
关键词 NO 目血 A NEW OXIDIZING AGENT PREPARED FROM nitrogen oxideS STUDIES ON TBP-NO_x AGENT TBP
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Nitrosation Reaction Without Nitrogen Oxide Waste Gas Emission and Its Engineering Practice 被引量:1
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作者 陈春光 冯亚青 +1 位作者 牛伟玮 陈学玺 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第4期442-446,共5页
The gas-liquid phase equilibrium is used in controlling the nitrosation reaction process. Decomposition of nitrous acid and oxidation side reaction.are suppressed in a closed reaction system. The system pressure is us... The gas-liquid phase equilibrium is used in controlling the nitrosation reaction process. Decomposition of nitrous acid and oxidation side reaction.are suppressed in a closed reaction system. The system pressure is used as the criterion of the end of reaction, avoiding excessive feeding and reducing'the decomposition'of nitrous acid. The head space of the reactor is used as the gas buffer, stabilizing the feeding fluctuations and inhibiting the side reaction, decomposition of nitrous acid. Nitrogen oxide concentration is controlled at the minimum level.Thus the zero release ofnitrogen ox!de waste gas can be achieved without using any absorption process. 展开更多
关键词 nitrosa-tion nitrogen oxides phase equilibrium
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Dynamic model for predicting nitrogen oxide concentration at outlet of selective catalytic reduction denitrification system based on kernel extreme learning machine 被引量:1
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作者 Ma Ning Liu Lei +2 位作者 Yang Zhenyong Yan Laiqing Dong Ze 《Journal of Southeast University(English Edition)》 EI CAS 2022年第4期383-391,共9页
To solve the increasing model complexity due to several input variables and large correlations under variable load conditions,a dynamic modeling method combining a kernel extreme learning machine(KELM)and principal co... To solve the increasing model complexity due to several input variables and large correlations under variable load conditions,a dynamic modeling method combining a kernel extreme learning machine(KELM)and principal component analysis(PCA)was proposed and applied to the prediction of nitrogen oxide(NO_(x))concentration at the outlet of a selective catalytic reduction(SCR)denitrification system.First,PCA is applied to the feature information extraction of input data,and the current and previous sequence values of the extracted information are used as the inputs of the KELM model to reflect the dynamic characteristics of the NO_(x)concentration at the SCR outlet.Then,the model takes the historical data of the NO_(x)concentration at the SCR outlet as the model input to improve its accuracy.Finally,an optimization algorithm is used to determine the optimal parameters of the model.Compared with the Gaussian process regression,long short-term memory,and convolutional neural network models,the prediction errors are reduced by approximately 78.4%,67.6%,and 59.3%,respectively.The results indicate that the proposed dynamic model structure is reliable and can accurately predict NO_(x)concentrations at the outlet of the SCR system. 展开更多
关键词 selective catalytic reduction nitrogen oxides principal component analysis kernel extreme learning machine dynamic model
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Simultaneous removal of ethanol, acetaldehyde and nitrogen oxides over V-Pd/γ-Al_2O_3-TiO_2 catalyst
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作者 Zhe Li Jing Wang Kai He Xia An Wei Huang Kechang Xie 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2011年第2期167-172,共6页
V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction (XRD), N2 adsorption-desorption (BET), X-ray photoelectron spectroscopy ... V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction (XRD), N2 adsorption-desorption (BET), X-ray photoelectron spectroscopy (XPS) and catalytic removal of ethanol, acetaldehyde and nitrogen oxides at low temperature (〈300 ?C) were used to assess the properties of the catalysts. The results showed that the sample with 1wt% vanadium exhibited an excellent catalytic performance for simultaneous removal of ethanol, acetaldehyde and nitrogen oxides. The conversions of ethanol, acetaldehyde and nitrogen oxides at 250 ?C were 100%, 74.4% and 98.7%, respectively. V-Pd/γ-Al2O3-TiO2 catalyst with 1 wt% vanadium showed the largest surface area and higher dispersion of vanadium oxide on the catalyst surface, and possessed a larger mole fraction of V4+ species and unique PdO species on the surface, which can be attributed to the strong synergistic effect among palladium, vanadium and the carriers. The higher activity of V-Pd/γ-Al2O3-TiO2 catalyst is related to the V4+ and Pd2+ species on the surface, which might be favorable for the formation of active sites. 展开更多
关键词 V-Pd/γ-Al2O3-TiO2 simultaneous removal ETHANOL ACETALDEHYDE nitrogen oxides
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Relationship of Tumor Necrosis Factor-α and Nitrogen Oxide with Treatment of Frequent Relapse Nephrotic Syndrome by Shenkangling(肾康灵)Granule in Children
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作者 王莉玲 郑健 +2 位作者 曾章超 董飞侠 吴群励 《Chinese Journal of Integrated Traditional and Western Medicine》 2003年第3期191-194,共4页
Objective: To observe the relationship of tumor necrosis factor-o (TNF-a) and nitrogen oxide (NO) with the treatment of frequent relapse nephrotic syndrome (FRNS) and to explore the patho-genesis of FRNS and the thera... Objective: To observe the relationship of tumor necrosis factor-o (TNF-a) and nitrogen oxide (NO) with the treatment of frequent relapse nephrotic syndrome (FRNS) and to explore the patho-genesis of FRNS and the therapeutic mechanism of Shenkangling (肾康灵,SKL) Granule in children. Methods: Sixty children suffering from FRNS were randomly divided into the treated group and control group, 30 in each, and the other 30 healthy children were taken as healthy group. The patients were treated with prednisone for a long-term course, and those with no effect or partial effect shown were treated with additional Tripterygium or Cytoxan in the control group, while in the treated group patients were treated with prednisone and additional SKL. The two groups were compared as to their changes of TNF-a, NO before and after treatment, and the relapses after treatment. Results: The levels of TNF-a and NO in the sick children before treatment were markedly higher than those after treatment and normal group (P< 0. 01). The positive correlation between TNF-o of FRNS cases and relapse risk displayed more significance than that between the relapse of FRNS and NO. The difference between treated group and control group was significant (P<0. 01). Conclusion: TNF-a can be regarded as the monitoring parameter of the active phase in FRNS, and the higher the level, the more possible the relapse would occur. SKL could markedly reduce the relapse rate of FRNS in children. 展开更多
关键词 children primary nephrotic syndrome frequent relapse tumor necrosis factor-a nitrogen oxide Shenkangling Granule
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Supported Manganese Oxide on Graphite Oxide: Catalytic Oxidation of Nitrogen Oxide in Waste Gas
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作者 吕伟 段元东 +1 位作者 孙秀枝 李登新 《Journal of Donghua University(English Edition)》 EI CAS 2015年第1期103-108,共6页
The catalytic oxidation of nitrogen oxide( NO) from waste gas was investigated using advanced oxidation process based on sulfate radicals. The manganese oxide immobilized on graphene oxide( GO) can activate peroxymono... The catalytic oxidation of nitrogen oxide( NO) from waste gas was investigated using advanced oxidation process based on sulfate radicals. The manganese oxide immobilized on graphene oxide( GO) can activate peroxymonosulfate( PMS) for the oxidation of NO in waste gas. The Mn3O4 / GO catalyst system was characterized via X-ray diffraction( XRD), Fourier transform infrared spectrocopy( FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy( XPS), energy dispersive X-ray spectroscopy( EDS),and scanning electron microscope( SEM).The results showed that Mn3O4 was distributed on GO. The Mn3O4 /GO catalyst system exhibited efficient activity for NO oxidation when the Mn3O4 /GO catalyst had an optimum Mn3O4 loading. In addition,the best catalytic oxidation could be achieved within 60 min with 0. 25 mmol /L Mn3 O4 /GO catalyst, and2 mmol /L PMS dosage at 25 ℃. The catalysts also exhibited stable performance after several rounds of regeneration. Therefore,the results may have significant technical implication for utilizing Mn3O4 /PMS to oxidize NO for offgas treatment. 展开更多
关键词 peroxymonosulfate(PMS) manganese oxide graphite oxide nitrogen oxide(NO)
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Indoor Nitrogen Oxides Occurrence, Modeling and Prediction
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作者 Ingrid Senitkova 《Journal of Civil Engineering and Architecture》 2012年第6期751-755,共5页
Outdoor air quality, building materials, HVAC (Heating, Ventilation, Air Conditioning) systems and people activity are important factors in human exposition of polluted indoor air. The degree of signification varies... Outdoor air quality, building materials, HVAC (Heating, Ventilation, Air Conditioning) systems and people activity are important factors in human exposition of polluted indoor air. The degree of signification varies in dependence on pollution character and its sources. Buildings eliminate significantly people exposition of outdoor pollutants, but on the other hand, buildings are significant source of indoor pollution. The contamination of indoor air is largely from the use of gas for heating and cooking appliances. A comprehensive analysis of indoor air pollution by nitrogen oxides shows that the extent of indoor air pollution and consequent exposure varies as a result of many factors mainly the differing dislribution of appliances and their level of use. This study aims to formulate a mathematical model for the production of nitrogen oxides indoors. The physical processes that determine the concentrations of indoor nitrogen oxides as a function of outdoor concentrations, indoor emission rates and building characteristics have been mathematically described. The mathematical model developed has been parameterized for typical Slovak residences. The modeling of the occurrence of indoor nitrogen oxides and verification of the model is presented in this paper. 展开更多
关键词 Indoors nitrogen oxides OCCURRENCE PREDICTION MODELING verification.
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Experimental study on removal nitrogen oxide of flue gas by using solid absorbents
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作者 YANG Jia-mo GAO Feng LIU Hua-yang 《Journal of Environmental Science and Engineering》 2008年第1期46-48,66,共4页
With the rapid development of modem industry and increase of consumption of the coal, petroleum and natural gas etc., emission of nitrogen oxide (NOx) from flue gas has air environment quality worsen day by day. Thi... With the rapid development of modem industry and increase of consumption of the coal, petroleum and natural gas etc., emission of nitrogen oxide (NOx) from flue gas has air environment quality worsen day by day. This research work is experimental study on removal low concentration NOx of flue gas by using solid absorbents. The experiment result shown that denification rate by modified activated carbon is higher than that of modified zeolite and rectorite. Average denitrification rate is 65.47% and maximum denitrification rate is 95.82% for activated carbon; average denitrification rate is respectively as 43.29% and 36.18%, maximum denitrification rate is respectively as 87.51% and 79.47% for modified zeolite and rectorite. Experiment results indicated that NO adsorption process of activated carbon can be described by Freudlich adsorption mode, K=0.143 and n=2.842 and Freudlich adsorption isotherm equation is: q = 0.143MO^0.3519. 展开更多
关键词 nitrogen oxide denitrification rate adsorption kinetics solid absorbents
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Selective catalytic reduction of nitrogen oxides over a modified silicoaluminophosphate commercial zeolite 被引量:1
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作者 Carolina Petitto Gérard Delahay 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第3期246-252,共7页
Nitrogen oxides(NOx:NO,NO2)are a concern due to their adverse health effects.Diesel engine transport sector is the major emitter of NOx.The regulations have been strengthened and to comply with them,one of the two ... Nitrogen oxides(NOx:NO,NO2)are a concern due to their adverse health effects.Diesel engine transport sector is the major emitter of NOx.The regulations have been strengthened and to comply with them,one of the two methods commonly used is the selective catalytic reduction of NOxby NH3(NH3-SCR),NH3being supplied by the in-situ hydrolysis of urea.Efficiency and durability of the catalyst for this process are highly required.Durability is evaluated by hydrothermal treatment of the catalysts at temperature above 800℃.In this study,very active catalysts for the NH3-SCR of NOxwere prepared by using a silicoaluminophosphate commercial zeolite as copper host structure.Characterizations by X-ray diffraction(XRD),scanning electron microscopy(SEM)and temperature programmed desorption of ammonia(NH3-TPD)showed that this commercial zeolite was hydrothermally stable up to 850℃ and,was able to retain some structural properties up to950℃.After hydrothermal treatment at 850℃,the NOxreduction efficiency into NH3-SCR depends on the copper content.The catalyst with a copper content of 1.25 wt.%was the most active.The difference in activity was much more important when using NO than the fast NO/NO2reaction mixture. 展开更多
关键词 DIESEL nitrogen oxides SCR process Copper ZEOLITE SILICOALUMINOPHOSPHATE
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Ground-high altitude joint detection of ozone and nitrogen oxides in urban areas of Beijing 被引量:1
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作者 Pengfei Chen Qiang Zhang +3 位作者 Jiannong Quan Yang Gao Delong Zhao Junwang Meng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2013年第4期758-769,共12页
Based on observational data of ozone (O3) and nitrogen oxide (NOx) mixing ratios on the ground and at high altitude in urban areas of Beijing during a period of six days in November 2011, the temporal and spatial ... Based on observational data of ozone (O3) and nitrogen oxide (NOx) mixing ratios on the ground and at high altitude in urban areas of Beijing during a period of six days in November 2011, the temporal and spatial characteristics of mixing ratios were analyzed. The major findings include: urban O3 mixing ratios are low and NOx mixing ratios are always high near the road in November. Vertical variations of the gases are significantly different in and above the planetary boundary layer. The mixing ratio of O3 is negatively correlated with that of NOx and they are positively correlated with air temperature, which is the main factor directly causing vertical variation of O3 and NOx mixing ratios at 600-2100 m altitude. The NOx mixing ratios elevated during the heating period, while the O3 mixing ratios decreased: these phenomena are more significant at high altitudes compared to lower altitudes. During November, air masses in the urban areas of Beijing are brought by northwesterly winds, which transport O3 and NOx at low mixing ratios. Due to Beijing's natural geographical location, northwest air currents arc beneficial to the dilution and dispersion of pollutants, which can result in lower O3 and NOx background values in the Beijing urban area. 展开更多
关键词 atmospheric pollution OZONE nitrogen oxides spatial distribution aircraft sound
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Multiphoton lonization Spectrum of Nitrogen Oxide by D^2∑←X2П
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作者 Lianshui Zhang Guiyin Zhang Xiaodong Yang Bo Sun Xiaohui Zhao College of Physics Science and Technology, Hebei University, China, Tel: 86-312-5079355 Fax: 86-312-5011174E-mail: gyzhang65@Yahoo.com.cn North China Electric Power University, Baoding 071003,China 《光学学报》 EI CAS CSCD 北大核心 2003年第S1期863-864,共2页
The resonance-enhanced multiphoton ionization (REMPI) spectrum of NO has been obtained. The spectral lines can be attributed to NO D2∑←X2П transitions. NO molecules are ionized via the resonant intermediate D2∑ st... The resonance-enhanced multiphoton ionization (REMPI) spectrum of NO has been obtained. The spectral lines can be attributed to NO D2∑←X2П transitions. NO molecules are ionized via the resonant intermediate D2∑ states and by (3+2) REMPI process. 展开更多
关键词 of IT on in ET by Multiphoton lonization Spectrum of nitrogen oxide by D^2 X2
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The effects of nitrogen fertilizer application on methane and nitrous oxide emission/uptake in Chinese croplands 被引量:18
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作者 SUN Bin-feng ZHAO Hong +2 位作者 LU Yi-zhong Lü Fei WANG Xiao-ke 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第2期440-450,共11页
The application of nitrogen(N) fertilizer to increase crop yields has a significant influence on soil methane(CH_4) and nitrous oxide(N_2O) emission/uptake.A meta-analysis was carried out on the effect of N appl... The application of nitrogen(N) fertilizer to increase crop yields has a significant influence on soil methane(CH_4) and nitrous oxide(N_2O) emission/uptake.A meta-analysis was carried out on the effect of N application on(i) CH_4 emissions in rice paddies,(ii) CH_4 uptake in upland fields and(iii) N_2O emissions.The responses of CH_4 emissions to N application in rice paddies were highly variable and overall no effects were found.CH_4 emissions were stimulated at low N application rates(〈100 kg N ha^(-1)) but inhibited at high N rates(〉200 kg N ha^(-1)) as compared to no N fertilizer(control).The response of CH_4 uptake to N application in upland fields was 15%lower than control,with a mean CH_4 uptake factor of-0.001 kg CH_4-C kg^(-1) N.The mean N_2O emission factors were 1.00 and 0.94%for maize(Zea mays) and wheat(Triticum aestivum),respectively,but significantly lower for the rice(Oryza sativa)(0.51%).Compared with controls,N addition overall increased global warming potential of CH_4 and N_2O emissions by 78%.Our result revealed that response of CH_4 emission to N input might depend on the CH_4concentration in rice paddy.The critical factors that affected CH_4 uptake and N_2O emission were N fertilizer application rate and the controls of CH_4 uptake and N_2O emission.The influences of application times,cropping systems and measurement frequency should all be considered when assessing CH_4 and N_2O emissions/uptake induced by N fertilizer. 展开更多
关键词 nitrogen fertilizer methane nitrous oxide global warming potential emission factor
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Microspheres of graphene oxide coupled to N-doped Bi_2O_2CO_3 for visible light photocatalysis 被引量:1
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作者 金瑞奔 蒋孝佳 +1 位作者 周仰原 赵建夫 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第5期760-768,共9页
Hierarchical microspheres of a graphene oxide(GO) coupled to N‐doped(BiO)2CO3 composite(N‐BOC‐GO) was synthesized by a simple hydrothermal approach. The N‐BOC‐GO composite gave enhancement in photocatalytic... Hierarchical microspheres of a graphene oxide(GO) coupled to N‐doped(BiO)2CO3 composite(N‐BOC‐GO) was synthesized by a simple hydrothermal approach. The N‐BOC‐GO composite gave enhancement in photocatalytic activity compared to the pure BOC and N‐BOC samples. With 1.0wt% GO, 62% NO removal was obtained with N‐BOC‐GO. The factors enhancing the photocatalytic performance were the high electron‐withdrawing ability and high conductivity of GO and improved visible light‐harvesting ability of N‐BOC‐GO with a 3D hierarchical architecture due to the surface scattering and reflecting(SSR) effect. An effective charge transfer from N‐BOC to GO was demonstrated by the much weakened photoluminescene intensity of the N‐BOC‐GO composite. This work highlights the potential application of GO‐based photocatalysts in air purification. 展开更多
关键词 Graphene oxide nitrogen-doped bismuth subcarbonate Hydrothermal approach Activity enhancement nitrogen oxide removal
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Analyzing the surface passivity effect of germanium oxynitride:a comprehensive approach through first principles simulation and interface state density
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作者 Sheng-Jie Du Xiu-Xia Li +8 位作者 Yang Tian Yuan-Yuan Liu Ke Jia Zhong-Zheng Tang Jian-Ping Cheng Zhi Deng Yu-Lan Li Zheng-Cao Li Sha-Sha Lv 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第5期74-84,共11页
High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy resolution.The surface passivation of HPGe has become crucial for achiev... High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy resolution.The surface passivation of HPGe has become crucial for achieving an extremely low energy threshold.In this study,first-principles simulations,passivation film preparation,and metal oxide semiconductor(MOS)capacitor characterization were combined to study surface passivation.Theoretical calculations of the energy band structure of the -H,-OH,and -NH_(2) passivation groups on the surface of Ge were performed,and the interface state density and potential with five different passivation groups with N/O atomic ratios were accurately analyzed to obtain a stable surface state.Based on the theoretical calculation results,the surface passivation layers of the Ge_(2)ON_(2) film were prepared via magnetron sputtering in accordance with the optimum atomic ratio structure.The microstructure,C-V,and I-V electrical properties of the layers,and the passivation effect of the Al/Ge_(2)ON_(2)/Ge MOS were characterized to test the interface state density.The mean interface state density obtained by the Terman method was 8.4×10^(11) cm^(-2) eV^(-1).The processing of germanium oxynitrogen passivation films is expected to be used in direct dark matter detection of the HPGe detector surface passivation technology to reduce the detector leakage currents. 展开更多
关键词 Surface passivation High purity germanium detector Germanium nitrogen oxide Interface state density
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Calculations and Sensitivity Analysis of Chlorine-,NO_(x)-,and Bromine-Depleting Cycles of Stratospheric Ozone
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作者 Ibraheem Alelmi Sen Nieh 《Journal of Environmental Science and Engineering(B)》 CAS 2024年第2期53-69,共17页
This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozon... This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozone-generating,and-depleting chemical reactions,the model calculated the transient,spatial changes of ozone under different physical-chemical-radiative conditions.Validation against the measured data demonstrated good accuracy,close match of our model with the observed ozone concentrations at both 20°S and 90°N locations.The deviation in the average concentration was less than 1% and in ozone profiles less than 17%.The impacts of various chlorine-(Cl),nitrogen oxides-(NO_(x)),and bromine-(Br)depleting cycles on ozone concentrations and distribution were investigated.The chlorine catalytic depleting cycle was found to exhibit the most significant impact on ozone dynamics,confirming the key role of chlorine in the problem of ozone depletion.Sensitivity analysis was conducted with levels of 25%,50%,100%,200%,and 400% of the baseline value.The combined cycles(Cl+NO_(x)+Br)showed the most significant influence on ozone behavior.The total ozone abundance above the South Pole could decrease by a small 3%,from 281 DU(Dubson Units)to 273 DU for the 25% level,or by a huge thinning of 60%to 114 DU for the 400% concentration level.When the level of chlorine gases increased beyond 200%,it would cause ozone depletion to a level of ozone hole(below 220 DU).The 2D Ozone Model presented in this paper demonstrates robustness,convenience,efficiency,and executability for analyzing complex ozone phenomena in the stratosphere. 展开更多
关键词 Ozone depletion 2-D model CHLORINE BROMINE nitrogen oxides sensitivity analysis total ozone abundance DU
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