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孟鲁司特联合噻托溴铵用于治疗哮喘-慢性阻塞性肺疾病重叠综合征患者的临床观察 被引量:39
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作者 徐高俊 潘选良 潘微微 《中国药师》 CAS 2019年第4期699-702,共4页
目的:观察孟鲁司特联合噻托溴铵对哮喘-慢性阻塞性肺疾病重叠综合征(ACOS)患者的治疗效果。方法:60例ACOS患者随机分为观察组和对照组,对照组在ACOS规范治疗基础上予噻托溴铵18μg qd吸入治疗,观察组在对照组基础上加用孟鲁司特钠片10 m... 目的:观察孟鲁司特联合噻托溴铵对哮喘-慢性阻塞性肺疾病重叠综合征(ACOS)患者的治疗效果。方法:60例ACOS患者随机分为观察组和对照组,对照组在ACOS规范治疗基础上予噻托溴铵18μg qd吸入治疗,观察组在对照组基础上加用孟鲁司特钠片10 mg,po,qd。连续治疗3个月后,观察两组患者治疗前后肺功能(FEV_1、FEV_1/FVC、FEV_1预计值)及血气分析(PaO_2及PaCO_2),6 min步行距离(6MWT),呼出气—氧化氮(FeNO),血清中IgE、CRP、IL-6和TNF-α变化。结果:治疗后,两组患者的肺功能、PaO_2和PaCO_2等指标均较治疗前明显改善,FeNO、CRP、IL-6、TNF-α和总IgE显著下降,6MWT显著升高(P<0.05);且观察组各项指标明显优于对照组(P<0.05)。结论:孟鲁司特联合噻托溴铵能够明显改善ACOS患者的肺功能及血氧状态,提高步行距离,降低血清中IgE和气道FeNO,降低气道炎症反应,有利于提高患者生存质量及改善患者预后。 展开更多
关键词 孟鲁司特 噻托溴铵 ACOS 血清中IgE 气-氧化氮
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Ammonia Volatilization and Deriitrification Losses from an Irrigated Maize-Wheat Rotation Field in the North China Plain 被引量:29
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作者 ZHANGYu-Ming CHENDe-Li +3 位作者 ZHANGJia-Bao R.EDIS HUChun-Sheng ZHUAn-Ning 《Pedosphere》 SCIE CAS CSCD 2004年第4期533-540,共8页
Ammonia (NH3) volatilization, denitrification loss, and nitrous oxide (N2O) emission were investigated from an irrigated wheat-maize rotation field on the North China Plain, and the magnitude of gaseous N loss from de... Ammonia (NH3) volatilization, denitrification loss, and nitrous oxide (N2O) emission were investigated from an irrigated wheat-maize rotation field on the North China Plain, and the magnitude of gaseous N loss from denitrification and NH3 volatilization was assessed. The micrometeorological gradient diffusion method in conjunction with a Bowen Ratio system was utilized to measure actual NH3 fluxes over a large area, while the acetylene inhibition technique (intact soil cores) was employed for measurement of denitrification losses and N2O emissions. Ammonia volatilization loss was 26.62% of the applied fertilizer nitrogen (N) under maize, while 0.90% and 15.55% were lost from the wheat field at sowing and topdressing, respectively. The differences in NH3 volatilization between different measurement events may be due to differences between the fertilization methods, and to differences in climatic conditions such as soil temperature.Denitrification losses in the fertilized plots were 0.67%-2.87% and 0.31%-0.49% of the applied fertilizer N under maize and wheat after subtracting those of the controls, respectively. Nitrous oxide emissions in the fertilized plots were approximately 0.08%-0.41% and 0.26%-0.34% of the applied fertilizer N over the maize and wheat seasons after subtracting those of the controls, correspondingly. The fertilizer N losses due to NH3 volatilization were markedly higher than those through denitrification and nitrous oxide emissions. These results indicated that NH3 volatilization was an important N transformation in the crop-soil system and was likely to be the major cause of low efficiencies with N fertilizer in the study area. Denitrification was not a very important pathway of N fertilizer loss, but did result in important evolution of the greenhouse gas N2O and the effect of N2O emitted from agricultural fields on environment should not be overlooked. 展开更多
关键词 ammonia volatilization DENITRIFICATION gaseous N loss N_2O emission
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Global air quality change during the COVID-19 pandemic:Regionally different ozone pollution responses COVID-19 被引量:5
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作者 Rong Tang Xin Huang +3 位作者 Derong Zhou Haikun Wang Jiawei Xu Aijun Ding 《Atmospheric and Oceanic Science Letters》 CSCD 2021年第4期45-51,共7页
The explosive spread of the 2019 novel coronavirus(COVID-19)provides a unique chance to rethink the relationship between human activity and air pollution.Though related studies have revealed substantial reductions in ... The explosive spread of the 2019 novel coronavirus(COVID-19)provides a unique chance to rethink the relationship between human activity and air pollution.Though related studies have revealed substantial reductions in primary emissions,obvious differences do exist in the responses of secondary pollutants,like ozone(0_(3))pollution.However,the regional disparities of O_(3)responses and their causes have still not been fully investigated.To better elucidate the interrelationship between anthropogenic emissions,chemical production,and meteorological conditions,O_(3)responses caused by lockdowns over different regions were comprehensively explored at a global scale.Observational signals of air-quality change were derived from multi-year surface measurements and satellite retrievals.With similar substantial drops in nitrogen dioxide(NO_(2)),ozone shows rising signals in most areas of both East Asia and Europe,even up to~14 ppb,while a non-negligible declining signal exists in North America,by about 2-4 ppb.Furthermore,the drivers behind the different O_(3)responses are discussed based on meteorological analysis and O_(3)sensitivity diagnosis.On the one hand,O_(3)responses to NO_(2)declines can be affected by the primary dependence on its precursors.On the other hand,it is also highly dependent on meteorological factors,especially temperature.Our study further highlights the great importance of taking into consideration both the regional disparities and synergistic effects of precursor reductions and meteorological influence for scientific mitigation of O_(3)pollution. 展开更多
关键词 Air quality COVID-19 lockdown OZONE Nitrogen dioxide METEOROLOGY
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Biomass gasification and Polish coal-fired boilers for process of reburning in small boilers 被引量:5
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作者 Hrycko Piotr Lasek Janusz Matuszek Katarzyna 《Journal of Central South University》 SCIE EI CAS 2013年第6期1623-1630,共8页
Reburning was applied to Polish automatic coal-fired retort boiler (25 kW).The use of bio-syngas reduced NOx emissions from the boiler by over 25%,below the significant level of 200 mg/m3 .Reburning was carried out us... Reburning was applied to Polish automatic coal-fired retort boiler (25 kW).The use of bio-syngas reduced NOx emissions from the boiler by over 25%,below the significant level of 200 mg/m3 .Reburning was carried out using an integrated system consisting of the boiler and a fixed-bed 60 kW (GazEla) gasification reactor.The process gas was continuously introduced above the coal burner of the boiler.The process parameters of the boiler and the gasifier were also measured and compared with the other units.Characteristic NOx emissions from automatic and manually operated boilers were also presented. 展开更多
关键词 NOx rebuming coal combustion biomass gasification
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Preparation and properties of transition metal nitrides caged in N-doped hollow porous carbon sphere for oxygen reduction reaction 被引量:4
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作者 Yan-juan LI Min WANG +5 位作者 Sa LIU Jing-xia GAO Shun YANG Zi-hao LIU Xiao-yong LAI Xiao YAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第5期1427-1438,共12页
A series of transition metal nitrides(MxNy,M=Fe,Co,Ni)nanoparticle(NP)composites caged in N-doped hollow porous carbon sphere(NHPCS)were prepared by impregnation and heat treatment methods.These composites combine the... A series of transition metal nitrides(MxNy,M=Fe,Co,Ni)nanoparticle(NP)composites caged in N-doped hollow porous carbon sphere(NHPCS)were prepared by impregnation and heat treatment methods.These composites combine the high catalytic activity of nitrides and the high-efficiency mass transfer characteristics of NHPCS.The oxygen reduction reaction results indicate that Fe2N/NHPCS has the synergistic catalytic performance of higher onset potential(0.96 V),higher electron transfer number(~4)and higher limited current density(1.4 times as high as that of commercial Pt/C).In addition,this material is implemented as the air catalyst for zinc−air battery that exhibits considerable specific capacity(795.1 mA·h/g)comparable to that of Pt/C,higher durability and maximum power density(173.1 mW/cm2). 展开更多
关键词 N-doped porous carbon transition metal nitrides Zn−air battery oxygen reduction reaction fuel cell
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Effect of exhaust gas recirculation and intake pre-heating on performance and emission characteristics of dual fuel engines at part loads 被引量:6
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作者 A.Paykani R.Khoshbakhti Saray +1 位作者 M.T.Shervani-Tabar A.Mohammadi-Kousha 《Journal of Central South University》 SCIE EI CAS 2012年第5期1346-1352,共7页
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... 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. 展开更多
关键词 dual fuel engine exhaust gas recirculation (EGR) EMISSION performance venturi EGR system
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Effect of Bu-Zhong-Yi-Qi-Tang on deficiency of N-glycan/nitric oxide and islet damage induced by streptozotocin in diabetic rats
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作者 xiao-Qiu Liu Ling Wu Xue-Jun Guo 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第14期1730-1737,共8页
AIM: To investigate the effect of Bu-Zhong-Yi-Qi-Tang (Decoction for Reinforcing Middle Jiao and Replenishing Qi) on deficiency of N-glycan/nitric oxide (NO) and islet damage induced by injecting two medium doses of s... AIM: To investigate the effect of Bu-Zhong-Yi-Qi-Tang (Decoction for Reinforcing Middle Jiao and Replenishing Qi) on deficiency of N-glycan/nitric oxide (NO) and islet damage induced by injecting two medium doses of streptozotocin (STZ). METHODS: Diabetes was induced by intraperitoneal injection of STZ at 55 mg/kg on day 1 and day 8. Islet damage was evaluated using a scoring system. Nitrite, nitrate, α-mannosidase and amylase activities were measured by colorimetry. N-glycan patterns of amylase were determined with lectin [ConA, pisum sativum agglutinin (PSA), peanut agglutinin (PNA), and lens culinaris agglutinin (LCA)] affinity precipitation method. RESULTS: Severe islet necrosis and mild islet atrophy were observed in diabetic rats. The number and size ofislets, the activities of α-mannosidase, amylase and nitrite were decreased, while the binding of PNA and LCA to amylase was increased. All of which were improved after treatment with Bu-Zhong-Yi-Qi-Tang. Islet damage was significantly correlated with nitrite, nitrate, α-mannosidase, amylase and the binding of LCA, PNA, and PSA to amylase.CONCLUSION: STZ-induced islet damage is related to N-glycan deficiency in proteins by blocking α-mannosidase activity and no deficiency, accumulation of unfolded proteins, and endoplasmic reticulum stress and activation of cellular signals, all of which are improved after treatment with Bu-Zhong-YiQi-Tang. 展开更多
关键词 N-Giycan Nitric oxide Diabetic rats Isletdamage Alpha mannosidase Bu-Zhong-Yi-Qi-Tang
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Spatial and seasonal patterns of atmospheric nitrogen deposition in North China 被引量:7
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作者 WANG Zhen ZHANG Xiuying +2 位作者 LIU Lei CHENG Miaomiao XU Junfeng 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第3期188-194,共7页
As one of the regions with intensive agriculture and rapid economic development in China,North China also has a high nitrogen(N)deposition.This study characterized the spatial pattern of N deposition in North China,co... As one of the regions with intensive agriculture and rapid economic development in China,North China also has a high nitrogen(N)deposition.This study characterized the spatial pattern of N deposition in North China,combining the tropospheric columns from satellite measurements and the simulated profiles from an atmospheric chemistry transport model.The total N deposition fluxes ranged from 16.3 to 106.5 kg N ha−1 yr−1,with an average of 54.5±17.2 kg N ha−1 yr−1.The high values were concentrated in urban and farmland areas,while low values were found in forests and grasslands with less human activities.Of the total N deposition,36%was deposited via precipitation,12%was deposited through dry particulate deposition,and the remaining 52%was comprised of dry gaseous deposition.For the seasonal variation of dry deposition,gaseous HNO3 and particulate NO3−were higher in winter and autumn,but lower in spring and summer.In contrast,gaseous NH3 and particulate NH4+were higher in spring and summer,but lower in winter and autumn.This is possibly caused by the seasonal differences in emission intensity between NOx and NH3 emission sources.The gaseous NO2 deposition did not show strong seasonal variation.The wet deposition was mainly affected by precipitation,with high values in summer and low values in winter.This research provides an objective spatial perspective and insight into the total N deposition in North China. 展开更多
关键词 North China SATELLITE NH3 NO2 atmospheric chemistry transport model
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Anthropogenic Direct Radiative Forcing of Tropospheric Ozone and Aerosols in 1850 and 2000 Estimated with IPCC AR5 Emissions Inventories 被引量:6
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作者 CHANG Wen-Yuan LIAO Hong 《Atmospheric and Oceanic Science Letters》 2009年第4期201-207,共7页
This study estimates direct radiative forcing by tropospheric ozone and all aerosols between the years 1850 and 2000, using the new IPCC AR5 (the Intergovernmental Panel on Climate Change Fifth Assessment Report) em... This study estimates direct radiative forcing by tropospheric ozone and all aerosols between the years 1850 and 2000, using the new IPCC AR5 (the Intergovernmental Panel on Climate Change Fifth Assessment Report) emissions inventories and a fully coupled chemistry-aerosol general circulation model. As compared to the previous Global Emissions Inventory Activity (GEIA) data, that have been commonly used for forcing estimates since 1990, the IPCC AR5 emissions inventories report lower anthropogenic emissions of organic carbon and black carbon aerosols and higher sulfur and NOx emissions. The simulated global and annual mean burdens of sulfate, nitrate, black carbon (BC), primary organic aerosol (POA), secondary organic aerosol (SOA), and ozone were 0.79, 0.35, 0.05, 0.49, 0.34, and 269 Tg, respectively, in the year 1850, and 1.90, 0.90, 0.11, 0.71, 0.32, and 377 Tg, respectively, in the year 2000. The estimated annual mean top of the atmosphere (TOA) direct radiative forcing of all anthropogenic aerosols based on the AR5 emissions inventories is -0.60 W m^-2 on a global mean basis from 1850 to 2000. However, this is -2.40 W m-2 when forcing values are averaged over eastern China (18-45°N and 95-125°E). The value for tropospheric ozone is 0.17 W m^-1 on a global mean basis and 0.24 W m^-2 over eastern China. Forcing values indicate that the climatic effect of aerosols over eastern China is much more significant than the globally averaged effect. 展开更多
关键词 IPCC AR5 emissions inventories AEROSOLS tropospheric ozone direct radiative forcing
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The role of alkali promoters in enhancing the direct N_2O decomposition reactivity over NiO catalysts 被引量:2
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作者 Bahaa M. Abu-Zied 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第11期1837-1845,共9页
Direct N2O decomposition has been investigated over bare NiO and a series of its alkali-promoted catalysts. These catalysts were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy (XPS) and fiel... Direct N2O decomposition has been investigated over bare NiO and a series of its alkali-promoted catalysts. These catalysts were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy. XPS analysis revealed that surface nickel is present in three forms: metal particles, NiO and Ni(OH)2. It is suggested that nickel(0) valent atoms are essential for the interaction with N2O molecules at the catalyst surfaces. Bare NiO exhibited a very low N2O decomposition reactivity. However, the alkali-containing catalysts exhibited a marked activity enhancement. 展开更多
关键词 N2O decomposition Greenhouse gas NiOAlkali-promotion Activity enhancement
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Effects of Atmospheric CO_2 Enrichment, Applied Nitrogen and Soil Moisture on Dry Matter Accumulation and Nitrogen Uptake in Spring Wheat 被引量:18
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作者 LIFUSHENG KANGSHAOZHONG 《Pedosphere》 SCIE CAS CSCD 2002年第3期207-218,共12页
Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitr... Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitrogen fertilizer (0, 50, 100, 150, and 200 mgkg^(-1) soil) to study the atmospheric CO_2 concentration effect on dry matter accumulation and Nuptake of spring wheat. The effects of CO_2 enrichment on the shoot and total mass depended largelyon soil nitrogen level, and the shoot and total mass increased significantly in the moderate to highN treatments but did not increase significantly in the low N treatment. Enriched CO_2 concentrationdid not increase more shoot and total mass in the drought treatment than in the well-wateredtreatment. Thus, elevated CO_2 did not ameliorate the depressive effects of drought and nitrogenstress. In addition, root mass decreased slightly and root/shoot ratio decreased significantly dueto CO_2 enrichment in no N treatment under well-watered condition. Enriched CO_2 decreased shoot Ncontent and shoot and total N uptake; but it reduced root N content and uptake slightly. Shootcritical N concentration was lower for spring wheat grown at 700 μmol mol^(-1) CO_2 than at 350μmol mol^(-1) CO_2 in both well-watered and drought treatments. The critical N concentrations were16 and 19 g kg^(-1) for the well-watered treatment and drought treatment at elevated CO_2 and 21 and26 g kg^(-1) at ambient CO_2, respectively. The reductions in the movement of nutrients to theplant roots through mass flow due to the enhancement in WUE (water use efficiency) and the increasein N use efficiency at elevated CO_2 could elucidate the reduction of shoot and root Nconcentrations. 展开更多
关键词 CO_2 enrichment critical N concentration dry matter nitrogen uptake soilmoisture
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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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Photocatalytic oxidation of nitric oxide from simulated flue gas by wet scrubbing using ultraviolet/TiO_2/H_2O_2 process 被引量:2
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作者 张波 仲兆平 付宗明 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期82-87,共6页
Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laborat... Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect.The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10-6 and TiO2/H2O2 solution volume of 600 m L. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process. 展开更多
关键词 photocatalytic oxidation nitric oxide UV/TiO2/H2O2 process
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Comparisons of the effects of different drying methods on soil nitrogen fractions:Insights into emissions of reactive nitrogen gases(HONO and NO) 被引量:4
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作者 WU Dianming DENG Lingling +7 位作者 LIU Yanzhuo XI Di ZOU Huilan WANG Ruhai SHA Zhimin PAN Yuepeng HOU Lijun LIU Min 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第3期224-231,共8页
Reactive nitrogen(Nr)emission from soils,e.g.,nitrous acid(HONO)and nitric oxide(NO),is a key process of the global nitrogen(N)cycle and has significant implications for atmospheric chemistry.To understand the underly... Reactive nitrogen(Nr)emission from soils,e.g.,nitrous acid(HONO)and nitric oxide(NO),is a key process of the global nitrogen(N)cycle and has significant implications for atmospheric chemistry.To understand the underlying mechanisms of soil Nr emissions,air-dried or oven-dried soils are commonly used in the laboratory.To date,few studies have compared the effects of different drying methods on soil Nr gas fluxes and N fractions.Here,the authors studied soil water content,pH,(in)organic N content,and Nr gas fluxes of air-dried,freeze-dried,oven-dried,and fresh soils from different land-use types.The results showed that the soil pH of air-dried and oven-dried samples was significantly lower compared with fresh soil from farmland and grassland,but higher compared with forest soil.The difference in soil pH between freeze-dried and fresh soil(mean±standard deviation:0.52±0.31)was the lowest.In general,all drying methods increased the soil NH4+-N,NO3−-N,and dissolved organic N contents compared with fresh soil(P<0.05).The maximum HONO and NO flux and total emissions during a full wetting–drying cycle of fresh soil were also increased by air-drying and oven-drying(P<0.001),but comparable with freeze-dried soil(P>0.2).In conclusion,all drying methods should be considered for use in studies on the land–atmosphere interface and biogeochemical N cycling,whereas the freeze-drying method might be better for studies involving the measurement of soil Nr gas fluxes. 展开更多
关键词 FREEZE-DRIED nitrogen cycling NOx soil pH gas flux
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Effect of Replacement of Headspace Gas on N_2O and CO_2Emissions in Anaerobic Incubation of Soil
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作者 CHEN TONGBINI S. STRUWE and A. KJΦLLERZ( Station for Ampecolopy and Environmental Technolopy, Institute of Geogmphy, Chinese Academy of Sciences, Beijing 100101 (China))( Department of Geneal Microbiology, University of Copenhagen, SΦlvgade 83H, DK-130 《Pedosphere》 SCIE CAS CSCD 1997年第4期303-310,共8页
To study effect of C2H2 and change of headspace gas on N2O emission, denitrification, as well as CO2emission, slumes of an agricultural soil were anaerobically incubated for 7 da3’s at 25 ℃. Both N2O reduction and C... To study effect of C2H2 and change of headspace gas on N2O emission, denitrification, as well as CO2emission, slumes of an agricultural soil were anaerobically incubated for 7 da3’s at 25 ℃. Both N2O reduction and CO2 emissions were inhibited by the addition of 100 mL L-1 of C2H2. However, the inhibition to CO2 emission was alleviated by the replacement of headspace gas, and the N2O emission was enhanced by the replacement. Acetylene disappeared evidently from the soil slumes during the incubation. Consequently results obtained from the traditional C2H2 blocking technique for determination of denitrification rate, especially in a long-time incubation, should be explained with care because of its side effect existing in the incubation environments without change of headspace gas. To reduce the possible side effect on the processes other than denitrification, it is suggested that headspace gas should be replaced several times during a long-time incubation. 展开更多
关键词 ACETYLENE anaerobic incubation CO_2 emission headspace gas N_2O emission
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Plateau Marsh Methane Oxidation as affected by Inorganic N
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作者 WANGZhi-Ping DUANYi +2 位作者 YANGJu-Rong LILing-Hao HANXing-Guo 《Pedosphere》 SCIE CAS CSCD 2004年第2期195-204,共10页
In a series of laboratory incubations using soils of two contrasting sitesfrom a temperate marsh on the Qinghai-Tibet Plateau, potential methane (CH_4) oxidation rates weremeasured to study the effects of inorganic N ... In a series of laboratory incubations using soils of two contrasting sitesfrom a temperate marsh on the Qinghai-Tibet Plateau, potential methane (CH_4) oxidation rates weremeasured to study the effects of inorganic N inputs on CH_4 oxidation. For adrained site, subsurfacepeat (5--15 cm) at an initial 20 mu L CH_4 L^(-1) showed a significantly different (P < 0.05) CH_4oxidation rate compared to other soil depths, with a maximal rate of 20.9 ng CH_4 gDW (dryweight)^(-1) h^(-1); the underlying mineral soil layers (15--30 and 30--50 cm) also had a strongCH_4 oxidation capacity at about an initial 2 000 mu L CH_4 L^(-1). With a waterlogged site, theCH_4 oxidation rate in an aerobic incubation was significantly greater (P < 0 05) in the surfacesoil layer (0--5 cm) compared to the 15--30 and 30--50 cm depths. There was generally no or a veryweak effect from addition of NO_3^- on CH_4 oxidation. In marked contrast, NH_4^+ salts, such as(NH_4)_2SO_4, NH_4Cl and NH_4NO_3, exhibited strong inhibitions, which varied as a function of theadded salts and the initial CH_4 level Increasing NH_4^+ usually resulted in greater inhibition andincreasing initial CH_4 concentrations resulted in less NH_4^+ inhibition on CH4 oxidation innatural high-altitude, low-latitude wetlands could be as important as has been reported foragricultural and forest soils. The NH_4^+ effects on the CH_4 oxidation rate need to be furtherinvestigated in a wide range of natural wetland soil types. 展开更多
关键词 AMMONIUM INHIBITION inorganic N methane oxidation plateau marsh
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Selective catalytic reduction of NO_x by H_2 over Pd/TiO_2 catalyst 被引量:2
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作者 Yiyang Zhang Hui Zeng +2 位作者 Bin Jia Zhihua Wang Zhiming Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第6期849-855,共7页
Pd/TiO2 catalysts prepared by three different methods(impregnation,deposition-precipitation,and polyethylene glycol reduction)were investigated in the selective catalytic reduction of NOx by H2(H2-SCR).It was found th... Pd/TiO2 catalysts prepared by three different methods(impregnation,deposition-precipitation,and polyethylene glycol reduction)were investigated in the selective catalytic reduction of NOx by H2(H2-SCR).It was found that the preparation method exerted a significant effect on the activity of the Pd/TiO2 catalyst,and that the catalyst prepared by the polyethylene glycol reduction method exhibited the highest activity in the reduction of NOx.Characterization of the catalyst showed that,in the Pd/TiO2 catalyst prepared by the polyethylene glycol reduction method,the existing Pd species was Pd0,which is the desirable species for the H2-SCR of NOx.In situ DRIFTS studies demonstrated that over this catalyst,more chelating nitrite and monodentate nitrite species formed,both of which are reactive intermediates in the H2-SCR of NOx.All of these factors account for the high activity of Pd/TiO2 prepared by the polyethylene glycol reduction method. 展开更多
关键词 Nitrogen oxides H2-SCR Pd/TiO2 In-situ DRIFTS
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Impacts of Secondary Aerosols on a Persistent Fog Event in Northern China 被引量:6
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作者 JIA Xing-Can GUO Xue-Liang 《Atmospheric and Oceanic Science Letters》 2012年第5期401-407,共7页
The chemistry version of the Weather Re- search and Forecasting model (WRF/Chem) was coupled with the anthropogenic emission inventory of David Streets to investigate the impacts of secondary aerosols on a persisten... The chemistry version of the Weather Re- search and Forecasting model (WRF/Chem) was coupled with the anthropogenic emission inventory of David Streets to investigate the impacts of secondary aerosols on a persistent fog event from 25 to 26 October 2007, in Northem China. The spatial distribution of the simulated fog is consistent with satellite observations, and the time-height distributions of the simulated boundary layer where the fog formed are also in good agreement with these observations. The sensitivity studies show that the secondary aerosols of SO4, NO3, and NH4 formed from gaseous precursors of SO2, NOx, and NH3 had substantial impacts on the formation processes and microphysical structure of the fog event. The decrease of the secondary aerosols obviously reduced the liquid water path and column droplet number concentration of the fog below the 1-km layer, and the corresponding area-averaged liquid water path and droplet number concentration of the fog decreased by 43% and 79%, respectively. The concentra- tions of NOx and NO3 were found to be extremely high in this case. The concentration of interstitial aerosol NO3 was much higher than the SO4 and NH4, but the concentration of SO4 was highest in the cloud-borne aerosols. The average activation ratios for SO4, NO3, and NH4 were 34%, 31%, and 30%, respectively, and the maximum ra- tios reached 62%, 86%, and 55% during the fog episode. 展开更多
关键词 secondary aerosol FOG WRF/Chem simulation
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Use of microelectrodes for electrochemical measurement of nitric oxide in natural seawater
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作者 张正斌 邢磊 +2 位作者 蔡卫君 任春艳 姜立庆 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2004年第4期373-380,共8页
In this paper, the application of a homemade Nafion and Co(Salen) modified platinum microelec-trode and an ISO-NOPMC microsensor (World Precision Instruments, USA ) to measure nitric oxide in natural seawater is repor... In this paper, the application of a homemade Nafion and Co(Salen) modified platinum microelec-trode and an ISO-NOPMC microsensor (World Precision Instruments, USA ) to measure nitric oxide in natural seawater is reported. These two microelectrodes are suitable for the measurement. In natural seawater, the sensitivity and stability of the ISO-NOPMC microsensor are higher than that of the homemade Nafion and Co(Salen) modified platinum microelectrode. 展开更多
关键词 Nafion and Co(Salen) modified platinum microelectrode ISO-NOPMC microsensor nitric oxide seawater
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Highway Green Open Area Planning Based on Annual Average Daily Vehicle Traffic
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作者 Ary Setyawan Setiyo Daru Cahyono 《Journal of Environmental Science and Engineering(A)》 2013年第3期162-165,共4页
The development of a territory always followed by population growth and increasing the life necessities of the society. This condition makes increasing transportation activity that causes environmental pollution. Poll... The development of a territory always followed by population growth and increasing the life necessities of the society. This condition makes increasing transportation activity that causes environmental pollution. Pollutants that are released by vehicle such as CO (carbon monoxide), SO2 (sulfur oxides), NO, (nitrogen oxides) are very harmful for public health. Indonesia is a country which has the high level of air pollution from transportation. One way to deal with the air pollution is to build green area (Ruang Terbuka Hijau) around the highway. Planning of open green area must be done comprehensively. There is an appropriate way to plan green area on the road by counting the number of AADV (annual average daily vehicles) (Lalu lintas harian rata rata) and estimated the amount of pollutantt that produced by vehicles. Calculation against the ability of plants in reducing pollutants and reached a unique relation between quantities of AADV by the number of plants that are necessary for reducing pollutants resulted by the traffic. The selection of plantation based on the shape of the tree canopy that provides the capacity of a pollutants reduction. After calculations the surface area of the tree leaves, the design of green area for highway can be reached so created an environmentally friendly and safe highway. 展开更多
关键词 Annual average daily vehicles POLLUTANTS green open area.
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