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Modeling radiative effects of haze on summer-time convective precipitation over North China: a case study

Xuying WANG, Bin ZHANG

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0840-3

摘要: We modeled the impact of haze radiative effects on precipitation in North China. Shortwave heating induced by haze radiative effects would reduce heavy rainfalls. Convection was the key factor that whether precipitation was enhanced or suppressed. Precipitation was often suppressed where CAPE, RH and updraft velocities were high. The impact of haze radiative effect on summertime 24-h convective precipitation over North China was investigated using WRF model (version 3.3) through model sensitivity studies between scenarios with and without aerosol radiative effects. The haze radiative effect was represented by incorporating an idealized aerosol optical profile, with AOD values around 1, derived from the aircraft measurement into the WRF shortwave scheme. We found that the shortwave heating induced by aerosol radiative effects would significantly reduce heavy rainfalls, although its effect on the post-frontal localized thunderstorm precipitation was more diverse. To capture the key factors that determine whether precipitation is enhanced or suppressed, model grids with 24-h precipitation difference between the two scenarios exceeding certain threshold (>30 mm or<-30 mm) were separated into two sets. Analyses of key meteorological variables between the enhanced and suppressed regimes suggested that atmospheric convection was the most important factor that determined whether precipitation was enhanced or suppressed during summertime over North China. The convection was stronger over places with precipitation enhancement over 30 mm. Haze weakened the convection over places with precipitation suppression exceeding 30 mm and caused less water vapor to rise to a higher level and thus further suppressed precipitation. The suppression of precipitation was often accompanied with relatively high convective available potential energy (CAPE), relative humidity (RH) and updraft velocities.

关键词: Haze     Aerosol radiative effects     Convective precipitation    

How aerosol direct effects influence the source contributions to PM

Litao Wang, Joshua S. Fu, Wei Wei, Zhe Wei, Chenchen Meng, Simeng Ma, Jiandong Wang

《环境科学与工程前沿(英文)》 2018年 第12卷 第3期 doi: 10.1007/s11783-018-1014-2

摘要: Beijing-Tianjin-Hebei area is the most air polluted region in China and the three neighborhood southern Hebei cities, Shijiazhuang, Xingtai, and Handan, are listed in the top ten polluted cities with severe PM pollution. The objective of this paper is to evaluate the impacts of aerosol direct effects on air quality over the southern Hebei cities, as well as the impacts when considering those effects on source apportionment using three dimensional air quality models. The WRF/Chem model was applied over the East Asia and northern China at 36 and 12 km horizontal grid resolutions, respectively, for the period of January 2013, with two sets of simulations with or without aerosol-meteorology feedbacks. The source contributions of power plants, industrial, domestic, transportation, and agriculture are evaluated using the Brute-Force Method (BFM) under the two simulation configurations. Our results indicate that, although the increases in PM concentrations due to those effects over the three southern Hebei cities are only 3%–9% on montly average, they are much more significant under high PM loadings (~50 μg·m when PM concentrations are higher than 400 μg m ). When considering the aerosol feedbacks, the contributions of industrial and domestic sources assessed using the BFM will obviously increase (e.g., from 30%–34% to 32%–37% for industrial), especially under high PM loadings (e.g., from 36%–44% to 43%–47% for domestic when PM >400 μg·m ). Our results imply that the aerosol direct effects should not be ignored during severe pollution episodes, especially in short-term source apportionment using the BFM.

关键词: Aerosol direct effect     PM2.5     Southern Hebei     WRF/Chem     Haze    

Response of organic aerosol characteristics to emission reduction in Yangtze River Delta region

《环境科学与工程前沿(英文)》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1714-0

摘要:

● The emission reduction causes significant change in organic aerosol composition.

关键词: Emission control     Secondary organic aerosol     Atmospheric oxidizing capacity     Holiday effects     COVID-19 lockdown    

Effects of two transition metal sulfate salts on secondary organic aerosol formation in toluene/NO

Biwu CHU, Jiming HAO, Junhua LI, Hideto TAKEKAWA, Kun WANG, Jingkun JIANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 1-9 doi: 10.1007/s11783-012-0476-x

摘要: Aerosol phase reactions play a very important role on secondary organic aerosol (SOA) formation, and metal-containing aerosols are important components in the atmosphere. In this study, we tested the effects of two transition metal sulfate salts, manganese sulfate (MnSO ) and zinc sulfate (ZnSO ), on the photochemical reactions of a toluene/NO photooxidation system in a 2 m smog chamber. By comparing photochemical reaction products of experiments with and without transition metal sulfate seed aerosols, we evaluated the effects of transition metal sulfate seed aerosols on toluene consumption, NO conversion and the formation of ozone and SOA. MnSO and ZnSO seed aerosols were found to have similar effects on photochemical reactions, both enhance the SOA production, while showing negligible effects on the gas phase compounds. These observations are consistent when varying metal sulfate aerosol concentrations. This is attributed to the catalytic effects of MnSO and ZnSO seed aerosols which may enhance the formation of condensable semivolatile compounds. Their subsequent partitioning into the aerosol phase leads to the observed SOA formation enhancement.

关键词: manganese sulfate     zinc sulfate     seed aerosols     toluene photooxidation     secondary organic aerosol    

Global sources, emissions, transport and deposition of dust and sand and their effects on the climate

Feng Wang, Xueqiu Zhao, Cynthia Gerlein-Safdi, Yue Mu, Dongfang Wang, Qi Lu

《环境科学与工程前沿(英文)》 2017年 第11卷 第1期 doi: 10.1007/s11783-017-0904-z

摘要: Dust and Sand Storms (DSS) originating in deserts in arid and semi-arid regions are events raising global public concern. An important component of atmospheric aerosols, dust aerosols play a key role in climatic and environmental changes at the regional and the global scale. Deserts and semi-deserts are the main source of dust and sand, but regions that undergo vegetation deterioration and desertification due to climate change and human activities also contribute significantly to DSS. Dust aerosols are mainly composed of dust particles with an average diameter of 2 m, which can be transported over thousands of kilometers. Dust aerosols influence the radiation budget of the earth-atmosphere system by scattering solar short-wave radiation and absorbing surface long-wave radiation. They can also change albedo and rainfall patterns because they can act as cloud condensation nuclei (CCN) or ice nuclei (IN). Dust deposition is an important source of both marine nutrients and contaminants. Dust aerosols that enter marine ecosystems after long-distance transport influence phytoplankton biomass in the oceans, and thus global climate by altering the amount of CO absorbed by phytoplankton. In addition, the carbonates carried by dust aerosols are an important source of carbon for the alkaline carbon pool, which can buffer atmospheric acidity and increase the alkalinity of seawater. DSS have both positive and negative impacts on human society: they can exert adverse impacts on human’s living environment, but can also contribute to the mitigation of global warming and the reduction of atmospheric acidity.

关键词: Dust and sand storm     Climate effects     Radiative forcing     Cloud condensation nuclei     Precipitation     Iron fertilizer    

Screening the emission sources of volatile organic compounds (VOCs) in China by multi-effects evaluation

He NIU,Ziwei MO,Min SHAO,Sihua LU,Shaodong XIE

《环境科学与工程前沿(英文)》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0828-z

摘要: We develop a multi-effect evaluation method to assess integrated impact of VOCs. Enable policy-makers to identify important emission sources, regions, and key species. Solvent usage and industrial process are the most important anthropogenic sources. Styrene, toluene, ethylene, benzene, and m/p-xylene are key species to be cut. Volatile organic compounds (VOCs) play important roles in the atmosphere via three main pathways: photochemical ozone formation, secondary organic aerosol production, and direct toxicity to humans. Few studies have integrated these effects to prioritize control measures for VOCs sources. In this study, we developed a multi-effects evaluation methodology based on updated emission inventories and source profiles, by combining the ozone formation potential (OFP), secondary organic aerosol potential (SOAP), and VOC toxicity data. We derived species-specific emission inventories for 152 sources. The OFPs, SOAPs, and toxicity of each source were estimated, the contribution and sharing of source to each of these adverse effects were calculated. Weightings were given to the three adverse effects by expert scoring, and then the integrated effect was determined. Taking 2012 as the base year, solvent use and industrial process were found to be the most important anthropogenic sources, accounting for 24.2% and 23.1% of the integrated effect, respectively, followed by biomass burning, transportation, and fossil fuel combustion, each had a similar contribution ranging from 16.7% to 18.6%. The top five industrial sources, including plastic products, rubber products, chemical fiber products, the chemical industry, and oil refining, accounted for nearly 70.0% of industrial emissions. Beijing, Chongqing, Shanghai, Jiangsu, and Guangdong were the five provinces contributing the largest integrated effects. For the VOC species from emissions showed the largest contributions were styrene, toluene, ethylene, benzene, and m/p-xylene.

关键词: Ozone formation     Secondary organic aerosol     Multi-effects evaluation     VOC abatement strategy    

Effects of seed particles Al

Xiao Zhang, Biwu Chu, Junhua Li, Chaozhi Zhang

《环境科学与工程前沿(英文)》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0936-4

摘要: Seed particles Al O , Al (SO ) and H SO were selected to investigate their effects on secondary aerosol (SA) formation in toluene/NO photooxidation under sulfur dioxide (SO ) and ammonia (NH ). Effect of seed particles on SA formation was related to their acid-base properties and the presence of acid or alkaline gases. Under NH -poor condition, SA formation increased with increasing SO concentration due to the acid-catalyzing effect of the oxidation products of SO (i.e. H SO ). The enhancing effect of SO became unobvious under NH -rich condition, because NH would eliminate the acid-catalyzing effect by neutralizing the acid products. Acidic seeds H SO accelerated SA formation under either SO or NH condition. Weak acidic Al (SO ) seeds didn’t affect obviously on SA formation. The inhibiting effect of amphoteric seeds Al O on SA formation was related to the presence of SO / NH due to their acid-base property. Under NH -poor condition, the inhibiting effect of Al O on SA formation decreased with increasing concentration of SO , while under NH -rich condition, the inhibiting effect wasn’t remarkable.

关键词: Seed particle     Secondary aerosol     Sulfur dioxide     Ammonia     Acid-catalyzing effect    

Effects of heavy rainfall on the composition of airborne bacterial communities

Gwang Il Jang, Chung Yeon Hwang, Byung Cheol Cho

《环境科学与工程前沿(英文)》 2018年 第12卷 第2期 doi: 10.1007/s11783-018-1008-0

摘要: Wet deposition scavenges particles and particle-associated bacteria from the air column, but the impact of raindrops on various surfaces on Earth causes emission of surface-associated bacteria into the air column. Thus, after rainfall, these two mechanisms are expected to cause changes in airborne bacterial community composition (BCC). In this study, aerosol samples were collected at a suburban site in Seoul, Korea before and after three heavy rainfall events in April, May, and July 2011. BCC was investigated by pyrosequencing the 16S rRNA gene in aerosol samples. Interestingly, the relative abundance of non-spore forming operational taxonomic units (OTUs) was always higher in post-rain aerosol samples. In particular, the absolute and relative abundances of airborne always increased after rainfall, whereas those of airborne , including and , consistently decreased. Marine bacterial sequences, which were temporally important in aerosol samples, also decreased after rainfall events. Further, increases in pathogen-like sequences were often observed in post-rain air samples. Rainfall events seemed to affect airborne BCCs by the combined action of the two mechanisms, with potentially adverse effects on human and plant health.

关键词: Aerosol     Bacteria     Community composition     Pyrosequencing     Rain    

Thermal radiative properties of metamaterials and other nanostructured materials: A review

Ceji FU, Zhuomin M. ZHANG

《能源前沿(英文)》 2009年 第3卷 第1期   页码 11-26 doi: 10.1007/s11708-009-0009-x

摘要: The ability to manufacture, control, and manipulate structures at extremely small scales is the hallmark of modern technologies, including microelectronics, MEMS/NEMS, and nano-biotechnology. Along with the advancement of microfabrication technology, more and more investigations have been performed in recent years to understand the influence of microstructures on radiative properties. The key to the enhancement of performance is through the modification of the reflection and transmission properties of electromagnetic waves and thermal emission spectra using one-, two-, or three-dimensional micro/nanostructures. This review focuses on recent developments in metamaterials–manmade materials with exotic optical properties, and other nanostructured materials, such as gratings and photonic crystals, for application in radiative energy transfer and energy conversion systems.

关键词: metamaterial     nanostructured material     thermal radiative property     radiative energy transfer    

A spectrally selective surface structure for combined photothermic conversion and radiative sky cooling

Bin ZHAO, Xianze AO, Nuo CHEN, Qingdong XUAN, Mingke HU, Gang PEI

《能源前沿(英文)》 2020年 第14卷 第4期   页码 882-888 doi: 10.1007/s11708-020-0694-z

摘要: The sun and outer space are the ultimate heat and cold sources for the earth, respectively. They have significant potential for renewable energy harvesting. In this paper, a spectrally selective surface structure that has a planar polydimethylsiloxane layer covering a solar absorber is conceptually proposed and optically designed for the combination of photothermic conversion (PT) and nighttime radiative sky cooling (RC). An optical simulation is conducted whose result shows that the designed surface structure (i.e., PT-RC surface structure) has a strong solar absorption coefficient of 0.92 and simultaneously emits as a mid-infrared spectral-selective emitter with an average emissivity of 0.84 within the atmospheric window. A thermal analysis prediction reveals that the designed PT-RC surface structure can be heated to 79.1°C higher than the ambient temperature in the daytime and passively cooled below the ambient temperature of approximately 10°C in the nighttime, indicating that the designed PT-RC surface structure has the potential for integrated PT conversion and nighttime RC utilization.

关键词: solar energy     photothermic conversion     radiative sky cooling     spectral selectivity     multilayer film    

Assessing the effects of different dielectrics on environmentally conscious powder-mixed EDM of difficult-to-machine

Jagdeep SINGH,Rajiv Kumar SHARMA

《机械工程前沿(英文)》 2016年 第11卷 第4期   页码 374-387 doi: 10.1007/s11465-016-0388-8

摘要:

Electrical discharge machining (EDM) is a well-known nontraditional manufacturing process to machine the difficult-to-machine (DTM) materials which have unique hardness properties. Researchers have successfully performed hybridization to improve this process by incorporating powders into the EDM process known as powder-mixed EDM process. This process drastically improves process efficiency by increasing material removal rate, micro-hardness, as well as reducing the tool wear rate and surface roughness. EDM also has some input parameters, including pulse-on time, dielectric levels and its type, current setting, flushing pressure, and so on, which have a significant effect on EDM performance. However, despite their positive influence, investigating the effects of these parameters on environmental conditions is necessary. Most studies demonstrate the use of kerosene oil as dielectric fluid. Nevertheless, in this work, the authors highlight the findings with respect to three different dielectric fluids, including kerosene oil, EDM oil, and distilled water using one-variable-at-a-time approach for machining as well as environmental aspects. The hazard and operability analysis is employed to identify the inherent safety factors associated with powder-mixed EDM of WC-Co.

关键词: WC     hazard and operability analysis (HAZOP)     discharging     aerosol concentration     dielectrics     powders    

Physical and chemical processes of wintertime secondary nitrate aerosol formation

Qi YING

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 348-361 doi: 10.1007/s11783-011-0343-1

摘要: The UCD/CIT model was modified to include a process analysis (PA) scheme for gas and particulate matter (PM) to study the formation of secondary nitrate aerosol during a stagnant wintertime air pollution episode during the California Regional PM /PM Air Quality Study (CRPAQS) where detailed measurements of PM components are available at a few sites. Secondary nitrate is formed in the urban areas from near the ground to a few hundred meters above the surface during the day with a maximum modeled net increase rate of 4 μg·m ·d during the study episode. The secondary nitrate formation rate in rural areas is lower due to lower NO . In the afternoon hours, near-surface temperature can be high enough to evaporate the particulate nitrate. In the nighttime hours, both the gas phase N O reactions with water vapor and the N O heterogeneous reactions with particle-bound water are important for secondary nitrate formation. The N O reactions are most import near the surface to a few hundred meters above surface with a maximum modeled net secondary nitrate increase rate of 1 μg·m ·d and are more significant in the rural areas where the O concentrations are high at night. In general, vertical transport during the day moves the nitrate formed near the surface to higher elevations. During the stagnant days, process analysis indicates that the nitrate concentration in the upper air builds up and leads to a net downward flux of nitrate through vertical diffusion and a rapid increase of surface nitrate concentration.

关键词: secondary nitrate aerosol     N2O5 heterogeneous reaction     process analysis    

Entropy flow, entropy generation, exergy flux, and optimal absorbing temperature in radiative transfer

Zeshao CHEN, Songping MO, Peng HU, Shouli JIANG, Gang WANG, Xiaofang CHENG,

《能源前沿(英文)》 2010年 第4卷 第3期   页码 301-305 doi: 10.1007/s11708-010-0006-0

摘要: Taking nonequilibrium radiative heat transfer between two surfaces as an example, the nonequilibrium thermodynamics of radiation is studied and discussed. The formulas of entropy flow, entropy generation, exergy flux, and optimal temperature of absorbing surface for maximum exergy output are derived. The result is a contribution to the thermodynamic analysis and optimization of solar energy utilization and can be applied in more complex radiative heat transfer cases.

关键词: radiative heat transfer     entropy generation     exergy     thermodynamics    

Computational fluid dynamics simulation of aerosol transport and deposition

Yingjie TANG, Bing GUO

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 362-377 doi: 10.1007/s11783-011-0365-8

摘要: In this article computational fluid dynamics (CFD) simulation of aerosol transport and deposition, i.e. the transport and deposition of particles in an aerosol, is reviewed. The review gives a brief account of the basics of aerosol mechanics, followed by a description of the general CFD approach for flow field simulation, turbulence modeling, wall treatments and simulation of particle motion and deposition. Then examples from the literature are presented, including CFD simulation of particle deposition in human respiratory tract and particle deposition in aerosol devices. CFD simulation of particle transport and deposition may provide information that is difficult to obtain through physical experiments, and it may help reduce the number of experiments needed for device design. Due to the difficulty of describing turbulent flow and particle-eddy interaction, turbulent dispersion of particles remains one of the greatest challenges for CFD simulation. However, it is possible to take a balanced approach toward quantitative description of aerosol dispersion using CFD simulation in conjunction with empirical relations.

关键词: computational fluid dynamics (CFD)     aerosol     transport     deposition    

Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

《能源前沿(英文)》 2013年 第7卷 第4期   页码 506-510 doi: 10.1007/s11708-013-0275-5

摘要: The collision frequency function for aerosol particles has already been calculated for the free molecule regime and for the continuum range. The present work, taking into account the influence of internal force fields such as magnetic force, electric force and molecular forces, created by particles themselves, recalculated the collision frequency in the case of particles much smaller than the mean free path of the gas (free molecule regime). Attractive forces increase naturally the collision frequency, while repulsive forces decrease it. The calculation was performed for all types of central forces deriving from a potential, including Coulomb forces and Van der Waals forces.

关键词: aerosol particles     collision frequency function     coagulation    

标题 作者 时间 类型 操作

Modeling radiative effects of haze on summer-time convective precipitation over North China: a case study

Xuying WANG, Bin ZHANG

期刊论文

How aerosol direct effects influence the source contributions to PM

Litao Wang, Joshua S. Fu, Wei Wei, Zhe Wei, Chenchen Meng, Simeng Ma, Jiandong Wang

期刊论文

Response of organic aerosol characteristics to emission reduction in Yangtze River Delta region

期刊论文

Effects of two transition metal sulfate salts on secondary organic aerosol formation in toluene/NO

Biwu CHU, Jiming HAO, Junhua LI, Hideto TAKEKAWA, Kun WANG, Jingkun JIANG

期刊论文

Global sources, emissions, transport and deposition of dust and sand and their effects on the climate

Feng Wang, Xueqiu Zhao, Cynthia Gerlein-Safdi, Yue Mu, Dongfang Wang, Qi Lu

期刊论文

Screening the emission sources of volatile organic compounds (VOCs) in China by multi-effects evaluation

He NIU,Ziwei MO,Min SHAO,Sihua LU,Shaodong XIE

期刊论文

Effects of seed particles Al

Xiao Zhang, Biwu Chu, Junhua Li, Chaozhi Zhang

期刊论文

Effects of heavy rainfall on the composition of airborne bacterial communities

Gwang Il Jang, Chung Yeon Hwang, Byung Cheol Cho

期刊论文

Thermal radiative properties of metamaterials and other nanostructured materials: A review

Ceji FU, Zhuomin M. ZHANG

期刊论文

A spectrally selective surface structure for combined photothermic conversion and radiative sky cooling

Bin ZHAO, Xianze AO, Nuo CHEN, Qingdong XUAN, Mingke HU, Gang PEI

期刊论文

Assessing the effects of different dielectrics on environmentally conscious powder-mixed EDM of difficult-to-machine

Jagdeep SINGH,Rajiv Kumar SHARMA

期刊论文

Physical and chemical processes of wintertime secondary nitrate aerosol formation

Qi YING

期刊论文

Entropy flow, entropy generation, exergy flux, and optimal absorbing temperature in radiative transfer

Zeshao CHEN, Songping MO, Peng HU, Shouli JIANG, Gang WANG, Xiaofang CHENG,

期刊论文

Computational fluid dynamics simulation of aerosol transport and deposition

Yingjie TANG, Bing GUO

期刊论文

Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

期刊论文