[Pollution Characteristics and Factors Influencing the Reduction in Ambient PM in Beijing from 2018 to 2020].

Air quality data from 33 environment sites and five regional sites from 2018 to 2020, as well as meteorological data, were used to research PM variation,spatial and temporal change, diurnal variation, and heavy pollutions in Beijing. The annual average mass concentrations of PM in Beijing were 51, 42, and 38 μg·m, which showed great progress in air quality improvement. However, the PM concentration in 2020 was still 8.

Cerium-Doped Iron Oxide Nanorod Arrays for Photoelectrochemical Water Splitting.

In this work, a simple one-step hydrothermal method was employed to prepare the Ce-doped FeO ordered nanorod arrays (CFT). The Ce doping successfully narrowed the band gap of FeO, which improved the visible light absorption performance. In addition, with the help of Ce doping, the recombination of electron/hole pairs was significantly inhibited.

[Transmission of Coronavirus via Aerosols and Influence of Environmental Conditions on Its Transmission].

The COVID-19 pandemic has endangered human health and production since 2019. As an emerging disease caused by SARS-CoV-2, its potential transmissibility via aerosols has caused heated debate. This work summarizes the current research findings on virus aerosol generation, aerodynamic properties, and environmental influencing factors on their survivability in order to elucidate coronavirus transmission via aerosols.

[Measuring the Condensable Particle Matter from a Stationary Source].

With the retrofitting of coal-fired power plants and steel plants for ultra-low-emission control, the concentration of filterable particles (FPM) from these sources is decreasing gradually. The condensable particle matter (CPM) draws more attention. The understanding of CPM emission concentration and chemical characteristics is still limited.

[Well-to-Wheels Fossil Energy Consumption and CO Emissions of Hydrogen Fuel Cell Vehicles in China].

Hydrogen fuel cell vehicles (FCVs) have the advantage of high energy efficiency and zero tailpipe emissions. They have been progressively commercialized in recent years. Hydrogen production has diversified technological pathways, which vary greatly in terms of energy and environmental impacts.

[Impact of Gusty Northwesterly Winds on Biological Particles in Winter in Beijing].

Biological aerosol particles play a crucial role in cloud formation and succession of ecosystems and have a large impact on human health. However, the variations in the concentration, composition, and viability of biological particles remain unclear. This study, conducted in January 2013 and January 2015 in Beijing, explores the influence of meteorological conditions on the variations in the concentration and composition of biological particles.

[Evaluation and Development of a Weighing Chamber by Using Saturated MgCl Solution].

In recent years, China has suffered a lot from atmospheric particles. Many studies of particles are based on filters. As a result, the accuracy of filter weighing is of great importance.

[Assessment of PM Pollution Mitigation due to Emission Reduction from Main Emission Sources in the Bejing-Tianjin-Hebei Region].

This study chose two months (January and July) in 2012 which represent winter and summer respectively, to assess the effects of fine particle(PM) pollution elimination due to emission control from different sectors in the Bejing-Tianjin-Hebei region by using CMAQ/2D-VBS modeling system. The results showed that, industrial emissions contributed most to PM pollution in the Beijing-Tianjin-Hebei region, followed by domestic emissions, while the contribution of per ton emission reduced for industrial sectors subject to domestic sectors. The total contribution and contribution of per ton emission reduced for transportation and power plant were both at low level.

[Number Concentration and Size Distribution of Particles Emitted by Light-duty Gasoline Vehicles].

In this study, three GDI (gasoline direct injection) and one PFI (port fuel injection) light-duty gasoline vehicles were characterized for their particle emission (number concentration and size distributions). Two condensation particle counters (CPC) with different activation efficiencies (50% cut off diameter) were used. It was found that the number concentration of particles emitted by GDI gasoline vehicle was approximately one order of magnitude higher than that from PFI gasoline vehicle.

[Characteristics of Speciated Atmospheric Mercury in Chongming Island, Shanghai].

Continuous monitoring of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particulate mercury (PBM) was conducted in the Dongtan wetland park in Chongming Island, Shanghai from March 2014 to February 2015. The average concentrations of GEM, RGM, and PBM were (2.75±1.

[Development and Performance Evaluation of a Supermicron Particle Generation System for Aerosol Instrument Calibration].

Accurate calibration of aerosol measurement instruments is critical for ensuring the data quality when sampling ambient particulate matter (PM) or those from emission sources. A system for calibrating these instruments was set up, which included an ultrasonic device to generate polydisperse supermicron particles, a chamber, and an aerodynamic particle spectrometer to measure particle size distribution. We verified its performance in stably generated testing aerosol with good spatial uniformity, controlled size distributions and concentrations.

[Application of a Two-stage Virtual Impactor in Measuring of PM and PM Emissions from Stationary Sources].

Recently, the Ministry of Environmental Protection of China started the development of emission inventories in fifteen Chinese cities. It includes the esmission of PM and PM from stationary sources. However, there is no national standard method in China for stationary source PM and PM sampling.

[Characterizing Beijing's Airborne Bacterial Communities in PM2.5 and PM1 Samples During Haze Pollution Episodes Using 16S rRNA Gene Analysis Method].

During 8th-14th Jan., 2013, severe particulate matter (PM) pollution episodes happened in Beijing. These air pollution events lead to high risks for public health.

[Development of a two stage virtual impactor for stationary source PM10 and PM2.5 sampling].

China does not have a national standard method for stationary source PM10 and PM2.5 sampling. Current commercial PM10/PM2.

[Sampling methods for PM2.5 from stationary sources: a review].

The new China national ambient air quality standard has been published in 2012 and will be implemented in 2016. To meet the requirements in this new standard, monitoring and controlling PM2,,5 emission from stationary sources are very important. However, so far there is no national standard method on sampling PM2.

[Spatial distribution characteristics of NMHCs during winter haze in Beijing].

NMHCs and NOx samples were simultaneously collected and analyzed in six urban and suburban representative sampling sites (Sihuan, Tian'anmen, Pinguoyuan, Fatou, Beijing Airport and Miyun) during a typical haze period in winter 2005, Beijing. The concentrations of NMHCs during the sampling period in descending order were: Sihuan (1101.29 microg x m(-3)) > Fatou (692.

[Design and evaluation of an aerosol nanoparticle generation system].

Aerosol nanoparticle generation is a key step in calibrating aerosol instruments, examining nanoparticle properties, and investigating aerosol formation mechanism in photochemical smog systems. An aerosol nanoparticle generation system (including an atomizer and a diffusion dryer) was developed and evaluated in this study. Aqueous solution of NaCl and isopropanol solution of DOS are used to generate solid and liquid aerosols, and the size distribution is measured by a scanning mobility particle spectrometer (SMPS).

[Characteristics of total gaseous mercury concentrations at a rural site of Yangtze Delta, China].

The ambient concentrations of total gaseous mercury (TGM) in Chongming Island, Shanghai, were continuously observed using the Tekran 2537B mercury analyzer from 15th September to 17th December, 2009. The average concentration of TGM during our observation is (2.50 +/- 1.

[Particle number size distribution near a major road with different traffic conditions].

The profiles of number concentration of ambient particles at a roadside site in Beijing were studied with different traffic conditions. A Scanning Mobility Particle Sizer (SMPS) was utilized to measure the number concentrations of fine and ultrafine (10-100 nm) particles in August 2008 and August 2009, which represented the normal and Olympic traffic conditions, respectively. Size distributions of particle number concentration were identified and their temporal variations were also discussed.

[Characteristics of volatile organic compounds (VOCs) emitted from biofuel combustion in China].

Biofuel combustion is an important source of VOCs in China. Measurements were conducted to determine the characteristics of VOCs emitted from combustion of 5 typical biofuels. A carbon mass balance method was used to determine VOCs emission factors.

Mechanism of monolignol biotransformation by Rhus laccases in water-miscible organic solutions.

Several important monolignols such as coniferyl alcohol were catalyzed using Rhus laccase (RL) from Rhus vernicifera in a water/acetone solution. The enzymatic mechanism is discussed in detail. Sites 6, β, and phenolic oxygen were the main active sites of phenylpropanoid compounds, which were first oxidized by the enzyme and then radicalized.

Particle size distribution and polycyclic aromatic hydrocarbons emissions from agricultural crop residue burning.

Laboratory measurements were conducted to determine particle size distribution and polycyclic aromatic hydrocarbons (PAHs) emissions from the burning of rice, wheat, and corn straws, three major agricultural crop residues in China. Particle size distributions were determined by a wide-range particle spectrometer (WPS). PAHs in both the particulate and gaseous phases were simultaneously collected and analyzed by GC-MS.

[Uncertainty analysis of emission inventory for volatile organic compounds from anthropogenic sources in China].

This study analyzed the uncertainties in the Chinese anthropogenic volatile organic compound (VOC) emission inventory. The uncertainty evaluation system for input information including activity data and emission factors was established to provide the probability density function of each input datum. Monte Carlo method was applied to propagate the uncertainties of emissions' input data and calculate the probability density function of total VOC emissions.

[Comprehensive fuzzy evaluation of nitrogen oxide control technologies for coal-fired power plants].

A multi-level assessment index system was established to quantitatively and comprehensively evaluate the performance of typical nitrogen oxide control technologies for coal-fired power plants. Comprehensive fuzzy evaluation was conducted to assess six NO, control technologies, including low NO, burner (LNB), over the fire (OFA), flue gas reburning (Reburning), selective catalyst reduction (SCR), selective non-catalyst reduction (SNCR) and hybrid SCR/SNCR. Case studies indicated that combination of SCR and LNB are the optimal choice for wall-fired boilers combusting anthracite coal which requires NO, removal efficiency to be over 70%, however, for W-flame or tangential boilers combusting bituminous and sub-bituminous coal which requires 30% NO, removal, LNB and reburning are better choices.

[Estimation and forecast of volatile organic compounds emitted from paint uses in China].

Based on the current consumptions and forecast consumptions of paints in China, using the volatile organic compounds (VOC) contents of paints calculated as emission factors, an emission inventory model was established to calculate provincial, sector-specific, and species-specific VOC emissions during 2005-2020. The results indicated that the VOC amount emitted from paint use was 1883 kt in 2005, of which aromatics, alcohol compounds, ester compounds, ether compounds and ketone compounds were the main species. The maximum incremental reactivity (MIR,O3/VOC) of VOC emitted in 2005 was about 3.