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Over the past decade, the emission standards and fuel standards in Beijing have been upgraded twice, and the vehicle structure has been improved by accelerating the elimination of 2.95 million old vehicles. Through the formulation and implementation of these policies, the emissions of carbon monoxide (CO), volatile organic compounds (VOCs), nitrogen oxides (NO

Non-road construction equipment (NRCE) has become a crucial contributor to urban air pollution. However, the current research on NRCE is still in its infancy, and the understanding of its pollutant emissions is not yet clear. In this study, multi-pollutant (CO, HC, NOx, PM

Road traffic constitutes a major source of air pollutants in urban Beijing, which are responsible for substantial premature mortality. A series of policies and regulations has led to appreciable traffic emission reductions in recent decades. To shed light on long-term (2014-2020) roadside air pollution and assess the efficacy of traffic control measures and their effects on public health, this study quantitatively evaluated changes in the concentrations of six key air pollutants (PM

Severe hazes occurred during 2016–2017 winter manifested winter haze was still a tough challenge in Beijing since the unprecedented haze in January 2013. Three haze episodes were identified from December 15, 2016 to January 15, 2017 in Beijing: the Red-Alert episode, the mixed haze-dust episode and the longest and heaviest Cross 2017 New Year's Haze episode. We analyzed the chemical components (water-soluble inorganic ions, carbonaceous components and trace elements) of multi-size airborne particles (PM1, PM2.5, PM10) samples, as well as the associated gaseous pollutants and meteorological parameters. Compared with the well-documented severe haze in January 2013, 2016–2017 winter haze was characterized by more stagnant synoptic conditions, sustained accumulation growth of PM enhanced by secondary reactions and regional contribution, as well as prominent fine particles mainly constituted by high concentrations of carbonaceous aerosol, secondary inorganic ions and anthropogenic elements. With strict pollution control measures since the enacting of Clean Air Action Plan in 2013, ambient concentrations of SO2, as well as SO42− and most anthropogenic elements in PM2.5 have decreased, whereas N O 3 − and N H 4 + concentration in PM2.5 increased by as high as 77.9% and 47.3% respectively compared with January 2013. The ratios of N O 3 − / S O 4 2 − in PM1, PM2.5, PM10 were higher than 1.0 no matter during normal period or haze period, totally different with the results in January 2013, which suggested the increased relative contribution from mobile sources and decreased contribution from coal combustion in Beijing. Nitrate and its precursors had become major concerns during winter haze in Beijing, although the rapid growth of sulfate still played an important role in the formation and evolution of extremely heavy haze events. Under ammonium-rich and high relative humidity conditions, N O 3 − was thought to mainly be produced by enhanced heterogeneous reactions. To prevent Beijing winter haze effectively, it's quite crucial to cut NOx, NH3, SO2 and VOCs emissions simultaneously and strengthen regional cooperation on air pollution control.

Cancer in human society is one of the most problematic health issue responsible for outnumbered deaths worldwide. The consumption of developed NPs in cancer diagnosis is a rapidly emerging field of bio-medical nanotechnology. Recent years, greener synthesized metal oxide hybrid nanoparticles have attracted great attention in cytotoxicity to different cancer therapy. Herein, we report that Duchesnea indica plant mediated green synthesis plant extract mediated Zn doped CuO (Zn/CuO) nanoparticles (NPs) prepared by hydrothermal method and these physico-chemical properties were characterized by XRD, UV-DRS, FTIR, and SEM with EDAX analytical techniques. The XRD pattern findings indicated that the crystal structure of the base CuO matrix are not distorted by the substitution of Cu2+ (0.73 A) ions by Zn2+ (0.65 A) ions. The average crystallite size of undoped and Zn/CuO NPs samples are found to be in between the range of 23 to 36 nm. And we can see that the Zn/CuO NPs are large aggregates, containing small particles with sizes of 100–300 nm with spherical shaped morphology by SEM and TEM microscopic images. The normal cell viability and cancer cell inhibition results on A-498 cancer cells and also normal human epithelial cells exhibited that no significant changes in the cell viability with normal kidney epithelial cells and doped NPs given excellent cell inhibition treated on A-498 kidney tumor cells.

In the past decade, due to the management policies and coal combustion controls in Beijing, the consumption of natural gas has increased gradually. Nevertheless, the research on the emission characteristics of gaseous pollutants emitted from gas-fired industrial boilers, especially considering the influence of low nitrogen (low-NOx) retrofit policy of gas boilers, is scarcely. In this study, based on literature and field investigations, onsite measurements of NOx, CO, NH3 and VOCs (Volatile Organic Compounds) emissions from gas-fired industrial boilers as well as the key factors that affected the emission of gaseous pollutants were discussed. Category-specific emission factors (EFs) of NOx, CO, NH3 and VOCs were obtained from the field measurements of 1107 “low-NOx” retrofitted and unabated gas-fired industrial boilers. Our results showed that operating load and control measures were the two key factors affecting the formation of gaseous pollutants. The EFs of NOx (EFNOx) and CO (EFCO) of atmospheric combustion boilers (ACBs) were much higher than the EFs of chamber combustion boilers (CCBs). The total emissions of NOx, CO, NH3 and VOCs from gas-fired industrial boilers in Beijing in the year of 2015 were estimated at 10489.6 t, 3272.8 t, 196.4 t and 235.4 t, respectively. Alkanes, BTEX, oxygenated VOCs and non-reactive organic matter were the four main chemical components of VOCs. As for the spatial distributions, the emissions of NOx, CO, NH3 and VOCs from gas-fired industrial boilers in Beijing were predominantly concentrated in central six urban districts. In the future, more detailed investigation and field tests for all kinds of gas-fired industrial boilers are still greatly needed to achieve more reliable estimations of atmospheric pollutants from gas-fired industrial boilers.

A high resolution regional emission inventory of typical primary air pollutants (PAPs) for the year 2012 in Beijing and the surrounding five provinces (BSFP) of North China is developed. It is compiled with the combination of bottom-up and top-down methods, based on city-level collected activity data and the latest updated specific emission factors for different sources. The considered sources are classified into 12 major categories and totally 36 subcategories with respect to their multi-dimensional characteristics, such as economic sector, combustion facility or industrial process, installed air pollution control devices, etc. Power plant sector is the dominant contributor of NOX emissions with an average contribution of 34.1%, while VOCs emissions are largely emitted from industrial process sources (33.9%). Whereas, other stationary combustion sources represent major sources of primary PM2.5, PM10 and BC emissions, accounting for 22.7%, 30.0% and 33.9% of the total emissions, respectively. Hebei province contributes over 34% of the regional total CO emissions because of huge volume of iron and steel production. By comparison, Shandong province ranks as the biggest contributor for NOX, PM10, PM2.5, SO2, VOCs and OC. Further, the BSFP regional total emissions are spatially distributed into grid cells with a high resolution of 9 km × 9 km using GIS tools and surrogate indexes, such regional population, gross domestic product (GDP) and the types of arable soils. The highest emission intensities are mainly located in Beijing-Tianjin-Tangshan area, Jinan-Laiwu-Zibo area and several other cities such as Shijiazhuang, Handan, and Zhengzhou. Furthermore, in order to establish a simple method to estimate and forecast PAPs emissions with macroscopic provincial-level statistical parameters in China, multi-parameter regression equations are firstly developed to estimate emissions outside the BSFP region with routine statistics (e.g. population, total final coal consumption, area of cultivated land and possession of civil vehicles) using the software 1stOpt. We find the estimated PAPs emissions of 31 provinces show close correlation with the well-recognized MEIC inventory. This high resolution multi-pollutants inventory provides necessary input data for regional air quality models that could help to identify and appoint the major influence sources, better understand the complex regional air pollution formation mechanism, and benefit for developing the corresponding joint prevention and control policies of regional complex air pollution in North China.

Henan is the most populous province and one of the most seriously polluted areas in China at present. In this study, we establish an integrated atmospheric emission inventory of primary air pollutants in Henan province for the target year of 2012. The inventory developed here accounts for detailed activity levels of 11 categories of primary anthropogenic emission sources, and determines the best available representation of emission factors. Further, we allocate the annual emissions into a high spatial resolution of 3km×3km with ArcGIS methodology and surrogate indices, such as regional population distribution and gross domestic product (GDP). Our results show that the emissions of VOCs, SO2, PM10, PM2.5, NOX, NH3, CO, BC and OC are about 1.15, 1.24, 1.29, 0.70, 1.93, 1.05, 7.92, 0.27 and 0.25milliontons, respectively. The majority of these pollutant emissions comes from the Central Plain Urban Agglomeration (CPUA) region, particularly Zhengzhou and Pingdingshan. By combining with the emission inventory with the WRF/Chem modeling and backward trajectory analysis, we investigate the temporal and spatial variability of air pollution in the province and explore the causes of higher pollutants concentrations in the region of CPUA during the heavily polluted period of January. The results demonstrate that intensive pollutants emissions and unfavorable meteorological conditions are the main causes of the heavy pollution. Besides, Weighted Potential Source Contribution Function (WPSCF) analysis indicates that local emissions remain the major contributor of PM2.5 in Henan province, although emissions from the neighboring provinces (e.g. Shanxi, Shaanxi, Anhui, and Shandong) are also important contributors.

In order to investigate the effects of the temporary strengthening of air quality assurance controlling measures during the Beijing 2015 IAAF World Championships and the Military Parade Assurance Period (MPAP) in China, we collected daily PM2.5 aerosol samples at three typical sites (urban downtown, suburban and rural background area, respectively) in Beijing and investigated the variations of concentration of the water-soluble ions, elemental constituents, organic carbon (OC) and elemental carbon (EC) in PM2.5 from Aug.15 to Sept.10, 2015. Simultaneously, 1-h high-resolution continuous monitoring results of PM2.5 mass concentration as well as the chemical components which were measured at another online monitoring urban site were incorporated. The concentrations of PM2.5 and other gaseous pollutants (SO2, NO2 and CO) during the parade control period (Aug.20-Sept.3) exhibited a substantially decrease compared with the concentrations during both the non-control (August 15 to August 19 and September 4 to September 10) period and the same period in 2014. According to the CMC results, the major components were identified as secondary inorganic aerosol (SIA, the combination of sulfate, ammonium and nitrate), mineral dust and particular organic matter (POM), which together accounted for more than 80% of PM2.5 in urban and suburban sites. POM is found to account for the largest proportion, and the obviously higher proportion of POM in the urban area revealed the significance contribution from vehicles. Compared with the non-control period, the mass concentrations of SIA and secondary organic carbon (SOC) decreased obviously. However, SIA and SOC are observed to play an important role in contributing to the rapid growth process of PM2.5 under unfavorable meteorological conditions during the control period. In view of the gradual improvement of air quality in Beijing, as well as the contribution of secondary aerosol formations in total PM2.5, effective control of primary gaseous pollutants and volatile organic compounds (VOCs) will be very significant for further lowering the concentration of PM2.5 in Beijing in normal time.

Residential coal combustion is considered to be an important source of air pollution in Beijing. However, knowledge regarding the emission characteristics of residential coal combustion and the related impacts on the air quality is very limited. In this study, we have developed an emission inventory for multiple hazardous air pollutants (HAPs) associated with residential coal combustion in Beijing for the period of 2000–2012. Furthermore, a widely used regional air quality model, the Community Multi-Scale Air Quality model (CMAQ), is applied to analyze the impact of residential coal combustion on the air quality in Beijing in 2012. The results show that the emissions of primary air pollutants from residential coal combustion have basically remained the same levels during the past decade, however, along with the strict emission control imposed on major industrial sources, the contribution of residential coal combustion emissions to the overall emissions from anthropogenic sources have increased obviously. In particular, the contributions of residential coal combustion to the total air pollutants concentrations of PM 10 , SO 2 , NO X , and CO represent approximately 11.6%, 27.5%, 2.8% and 7.3%, respectively, during the winter heating season. In terms of impact on the spatial variation patterns, the distributions of the pollutants concentrations are similar to the distribution of the associated primary HAPs emissions, which are highly concentrated in the rural-urban fringe zones and rural suburb areas. In addition, emissions of primary pollutants from residential coal combustion are forecasted by using a scenario analysis. Generally, comprehensive measures must be taken to control residential coal combustion in Beijing. The best way to reduce the associated emissions from residential coal combustion is to use economic incentive means to promote the conversion to clean energy sources for residential heating and cooking. In areas with reliable energy supplies, the coal used for residential heating can be replaced with gas-burning wall-heaters, ground-source heat pumps, solar energy and electricity. In areas with inadequate clean energy sources, low-sulfur coal should be used instead of the traditional raw coal with high sulfur and ash content, thereby slightly reducing the emissions of PM, SO 2 , CO and other toxic pollutants.

China has become the largest producer of iron and steel throughout the world since 1996. However, as an energy-and-pollution intensive manufacturing sector, a detailed comprehensive emission inventory of air pollutants for iron and steel industry of China is still not available. To obtain and better understand the temporal trends and spatial variation characteristics of typical hazardous air pollutants (HAPs) emissions from iron and steel production in China, a comprehensive emission inventory of multiple air pollutants, including size segregated particulate matter (TSP/PM10/PM2.5), gaseous pollutants (SO2, NOx, CO), heavy metals (Pb, Cd, Hg, As, Cr, Ni etc.), as well as the more dangerous PCDD/Fs, is established with the unit-based annual activity, specific dynamic emission factors for the historical period of 1978-2011, and the future potential trends till to 2050 are forecasted by using scenario analysis. Our results show that emissions of gaseous pollutants and particulate matter have experienced a gradual increase tendency since 2000, while emissions of priority-controlled heavy metals (Hg, Pb, As, Cd, Cr, and Ni) have exhibited a short-term fluctuation during the period of 1990 to 2005. With regard to the spatial distribution of HAPs emissions in base year 2011, Bohai economic circle is identified as the top emission intensity region where iron and steel smelting plants are densely built; within iron and steel industry, blast furnaces contribute the majority of PM emissions, sinter plants account for most of gaseous pollutants and the majority of PCDD/Fs, whereas steel making processes are responsible for the majority of heavy metal emissions. Moreover, comparisons of future emission trends under three scenarios indicate that advanced technologies and integrated whole process management strategies are in great need to further diminish various hazardous air pollutants from iron and steel industry in the future.

Coal-fired combustion is recognized as a significant anthropogenic source of atmospheric compounds in Beijing, causing heavy air pollution events and associated deterioration in visibility. Obtaining an accurate understanding of the temporal trends and spatial variation characteristics of emissions from coal-fired industrial combustion is essential for predicting air quality changes and evaluating the effectiveness of current control measures. In this study, an integrated emission inventory of primary air pollutants emitted from coal-fired industrial boilers in Beijing is developed for the period of 2007–2013 using a technology-based approach. Future emission trends are projected through 2030 based on current energy-related and emission control policies. Our analysis shows that there is a general downward trend in primary air pollutants emissions because of the implementation of stricter local emission standards and the promotion by the Beijing municipal government of converting from coal-fired industrial boilers to gas-fired boilers. However, the ratio of coal consumed by industrial boilers to total coal consumption has been increasing, raising concerns about the further improvement of air quality in Beijing. Our estimates indicate that the total emissions of PM 10 , PM 2.5 , SO 2 , NO x , CO and VOCs from coal-fired industrial boilers in Beijing in 2013 are approximately 19,242 t, 13,345 t, 26,615 t, 22,965 t, 63,779 t and 1406 t, respectively. Under the current environmental policies and relevant energy savings and emission control plans, it may be possible to reduce NO x and other air pollutant emissions by 94% and 90% by 2030, respectively, if advanced flue gas purification technologies are implemented and coal is replaced with natural gas in the majority of existing boilers.

s A multiple-year comprehensive emission inventory of typical hazardous air pollutants (HAPs) from China's cement industry for the period 1980–2012, has been established by using technology-based dynamic emission factors and detailed annual plant-specific cement production from different types of kilns. Our results show that the total emissions of various HAPs (SO 2 , NO X , CO, PM, Hg, Cd, Cr, Pb, Zn, As, Ni and Cu) have rapidly increased by about 1–21 times at an annual average growth rate of 1–10% over the past three decades. Remarkably uneven spatial allocation features of these pollutants among provinces are observed. HAPs emissions are primarily concentrated in the eastern and coastal provinces due to the concentration of cement plants and their huge volume of coal consumption. We predict the future emission trends of HAPs through 2050 based on industry construction and policy guidance, and our scenario analysis indicates that HAPs emissions will drop substantially because of the combined effects of cement production yields reduction and the increasing application rate of various air pollution control devices. The study suggests that highlighted attention should be paid to this energy-intensive industry to ensure stricter emission standards are implemented for these HAPs emissions in the future.

China is the most populous country in the world. The amount of death population has reached 9.65 million and 49.5% of human corpses are cremated by about 1700 crematories spread throughout the country in 2012, leading to considerable discharge of various hazardous air pollutants (HAPs) into the atmosphere and great concerns on regional air quality and health risks for surrounding residents. By using the practicable or best available emission factors, for the first time, a multiple-year emission inventory of typical hazardous air pollutants discharged from crematories in the Chinese mainland, has been established for the historical period of 1990–2012, and the future trends of HAPs emissions until 2030 are forecasted based on three scenarios analysis. Our results show that the total emissions have gradually increased to 906 t of NO X , 443 t of SO 2 , 2713 t of CO, 477.7 t of PM, 377 t of HCl, 36 t of H 2 S, 25 t of NH 3 , 62 t of NMVOCs, 592 kg of Hg, 48 kg of Pb, 14 kg of Cd, 53 kg of As, 40 kg of Cr, 37 kg of Cu, 51 kg of Ni, and 96 g of PCDD/Fs as TEQ (toxic equivalent quantity) by the year 2012. Under the business-as-usual (BAU) scenario, various HAPs emitted from cremators would continuously increase with an average growth rate of 3% till to 2030; whereas the emissions will peak at around 2015 and then decline gradually with varied speed under the two improved control scenarios. To mitigate the associated air pollution and health risks caused by crematories, it is of great necessary for implementing more strict emission standards, applying combustion optimization and requiring installation of best available flue gas purification system, as well as powerful supervision for sound operation of crematories.

Natural sources, such as soil and wind-erosion dust (SWD), biomass open burning (BOB), sea salt spray (SSAS) and biogenic source (BIO), are major contributors to atmospheric emissions of trace elements (TEs) globally. In this study, we used a comprehensive approach to account for area-, production- and biofuel consumption-based emission factor calculation methods, and thus developed an integrated high-resolution emission inventory for 15 types of TEs (As, B, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, V and Zn) originated from natural sources in China for the year 2015. The results show that national emissions of TEs in 2015 range from 7.45 tons (Hg) to 1, 400 tons (Zn) except for the extremely high emissions of Mn (10, 677 tons). SWD and BIO are identified as the top two source contributors, accounting for approximately 67.7% and 26.1% of the total emissions, respectively. Absolute emissions of TEs from natural sources are high in the Xinjiang, Inner Mongolia and Tibet autonomous regions with large areas of bare soil and desert. However, emission intensity of TEs per unit area in the Southern provinces of China is higher than those in Northern China and Southwestern China, with the Yunnan and Sichuan provinces displaying the highest emission intensity. Our results suggest that controlling SWD can play a significant role in reducing fugitive particulate matter and the associated emissions of TEs from natural sources in China; and desertification control is particularly critical in the Northwest provinces where the majority of deserts are located.

This paper presents the scenario forecast of global atmospheric antimony (Sb) emissions from anthropogenic activities till 2050. The projection scenarios are built based on the comprehensive global antimony emission inventory for the period 1995–2010 which is reported in our previous study. Three scenarios are set up to investigate the future changes of global antimony emissions as well as their source and region contribution characteristics. Trends of activity levels specified as 5 primary source categories are projected by combining the historical trend extrapolation with EIA International energy outlook 2013, while the source-specific dynamic emission factors are determined by applying transformed normal distribution functions. If no major changes in the efficiency of emission control are introduced and keep current air quality legislations (Current Legislation scenario), global antimony emissions will increase by a factor of 2 between 2010 and 2050. The largest increase in Sb emissions is projected from Asia due to large volume of nonferrous metals production and waste incineration. In case of enforcing the pollutant emission standards (Strengthened Control scenario), global antimony emissions in 2050 will stabilize with that of 2010. Moreover, we can anticipate further declines in Sb emissions for all continents with the best emission control performances (Maximum Feasible Technological Reduction scenario). Future antimony emissions from the top 10 largest emitting countries have also been calculated and source category contributions of increasing emissions of these countries present significant diversity. Furthermore, global emission projections in 2050 are distributed within a 1° × 1°latitude/longitude grid. East Asia, Western Europe and North America present remarkable differences in emission intensity under the three scenarios, which implies that source-and-country specific control measures are necessary to be implemented for abating Sb emissions from varied continents and countries in the future.

Let H"1,H"2 be two Hilbert spaces over the complex field C and let T,[email protected]:H"1->H"2 be two bounded linear operators with the M-P generalized inverse T^+. If R(T)@?R(T)^@?=0, we say that T is the stable perturbation of T. In this paper, we give five equivalent conditions that make T being the stable perturbation of T under the assumption @?T^[email protected][email protected][email protected]@?

Let L be a subspace of C^n and P"L be the orthogonal projection of C^n onto L. Then for the nxn matrix A, the generalized Bott-Duffin (B-D) inverse A"("L")^(^+^) is given by A"("L")^(^+^)=P"L(AP"L+I-P"L)^+. In this paper we will give an expression of A"("L")^(^+^). In the rest of the part, the perturbation analysis of A"("L")^(^+^) and the least squares solution of the generalized B-D equation Ax+y=b for x@?L and y@?L^@? will be established under certain small perturbation of P"LAP"L.

A perturbation theory for the Bott-Duffin inverse A"("L")^(^+^) of A with respect to a subspace L is developed. The perturbation bound for the solution of the constrained system Ax+y=b,[email protected]?L,[email protected]?L^@? is established, where [email protected]?M"n(C), a subspace [email protected]?C^n and [email protected]?C^n. Meanwhile this paper shows the generalized Bott-Duffin condition number K"g"B"D(A)[email protected][email protected][email protected]?A"("L")^(^+^)@? to be minimum in the inequality of error analysis.

LetX1, X2be two Banach spaces over the complex fieldCand letT:X1 → X2be a bounded linear operator with the generalized inverseT+. Let T = T + δT be a bounded linear operator with ‖T+‖ ‖δT‖ dim ker T = dim ker T ∞ or R( T ) ∩ Ker T + = 0 . Then T has the generalized inverse T = (I + T + δT) −1 T + with ‖ T + ‖ ≤ ‖T + ‖ 1 − ‖T + ‖ ‖δT‖ . This result generalizes Theorem 3.9 of Na . Using this result, we give some results of the perturbation analysis for the operator equationTx = b.

Let H 1 , H 2 be two Hilbert spaces over the same field, and let T : H 1 → H 2 be a bounded linear operator with closed range. We give a complete description of the perturbation analysis for the least squares solution to the operator equation T x = y , where x ∈ H 1 , y ∈ H 2 .