•Open-access traffic congestion index data were used to estimate vehicle emissions.•High-resolution vehicle emissions of CO2 and major air pollutants were estimated.•Rush-hour traffic could cause ...14.3–30.4% excess emissions in a business district.•Freight transportation greatly increase fleet-level emissions of NOX, PM2.5 and CO2.
The high populations of vehicles in global megacities have raised serious mobility and sustainability challenges, such as traffic congestion, air pollution deterioration and energy consumption issues. Detailed emission inventories at the link level are a prerequisite to accurately quantifying ambient pollution concentrations and identifying hotspots of human exposure within urban areas. The increasing adoption of intelligent transportation system data in smart-city initiatives worldwide has offered unprecedented opportunities for improving transportation air quality management. Based on the open-access traffic congestion index, we construct a high-resolution emission inventory of hourly fluxes of air pollutants and carbon dioxide from on-road vehicles over the whole road network in Shenzhen, China. Fine-grained quantification of ‘excess’ emissions from rush-hour traffic is explored, finding varied emission enhancement (14.3–30.4%) for different pollutants, as well as 24.3–26.8% and 19.6–22.0% ‘excess’ consumption for gasoline and diesel, respectively, in a central business district of Shenzhen during the rush hour periods. Also, we quantified the impacts of freight activities on pollutant emissions that freight activities can largely increase the street-level emission rates of nitrogen oxides, fine particulate matter and carbon dioxide, in which heavy-duty trucks share up to 50% of the total emissions of these species. This study provides a novel approach of high-resolution traffic emission inventory construction that can be potentially utilized in many types of cities, particularly for cities suffering from data-sparse situations, and further strengthen the intelligence and accuracy of vehicle emission management.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The serious fine particle (PM2.5) pollution in China causes millions of premature deaths. Driven by swift economic growth and stringent control policies, air pollutant emissions in China have changed ...significantly in the last decade, but the change in the source contribution of PM2.5-related health impacts remains unclear. In this study, we develop a multi-pollutant emission inventory in China for 2005–2015, and combine chemical transport modeling, ambient/household exposure evaluation and health impact assessment to quantify the contribution of eight emission sectors to PM2.5 exposure and associated health risk. From 2005 to 2015, the mortality due to PM2.5 from ambient air pollution (AAP) decreases from 1.04 (95% confidence interval, 0.84–1.25) million to 0.87 (0.70–1.04) million. The agricultural sector contributes 25% and 32% to ambient PM2.5-attributed mortality in 2005 and 2015, respectively, representing the largest contributor during this period. The contribution of power plants drops monotonously from 13% to 6%. The percentage contribution of industrial process drops significantly while the contribution of industrial combustion stays the same level. The overall contribution of industry is still as large as 26% in 2015 in spite of strict control measures. For transportation, despite strict emission standards, its contribution increases remarkably due to the rapid growth of vehicle population. When both ambient and household PM2.5 exposures are taken into account, the mortality due to integrated population-weighted exposure to PM2.5 (IPWE) drops from 1.78 (1.46–2.09) million in 2005 to 1.28 (1.05–1.52) million in 2015. Most of the IPWE reduction comes from domestic combustion as a result of urbanization and improved income, whereas this sector remains the largest contributor (58%) to IPWE-related health risk in 2015. Our results suggest that the government should dynamically adjust the air pollution control strategy according to the change in source contributions. Domestic combustion and agriculture should be prioritized considering their predominant contributions to mortality and the lack of effective control policies. More stringent control measures for industry and transportation are necessary since the existing policies have not adequately reduced their health impacts. Electricity production is no longer the top priority of air pollution control policies given its lower health impact compared with that of other sources.
•We analyze source contribution to PM2.5 exposure and related mortality in China.•Domestic combustion and agriculture contribute most but lack control policies.•More stringent control measures are needed for industry and transportation.•Electricity is no longer the top priority of air pollution control policies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Existing image enhancement methods fall short of expectations because with them it is difficult to improve global and local image contrast simultaneously. To address this issue, we propose a ...histogram equalization-based method called RG-CACHE. It adapts to the data-dependent requirements of brightness enhancement and improves the visibility of details without losing the global contrast. RG-CACHE incorporates the spatial information provided by image context into density estimation for discriminative histogram equalization. To minimize the adverse effect of nonuniform illumination, we propose defining spatial information on the basis of image reflectance estimated with edge-preserving smoothing. RG-CACHE works particularly well for determining how the background brightness should be adaptively adjusted and for revealing useful image details hidden in the dark. To handle the loss of details due to the monotonicity of the intensity mapping function, we further propose a post-processing method to approximate RG-CACHE with a brightness transformation function corresponding to a parameterized camera response function. This method is called comparametric approximation. It takes into account a regression problem, in which the parameters of the camera response function are chosen so that the converted intensities are optimally matched to the image enhanced by RG-CACHE. Comparametric approximation is especially suitable for recovering useful image details that tend to be suppressed due to insufficient reflectance contrast.
(family Musaceae) is monocotyledonous plants in order Zingiberales, which grows in tropical and subtropical regions. It is one of the most important tropical fruit trees in the world. Herein, we used ...next-generation sequencing technology to assemble and perform in-depth analysis of the chloroplast genome of nine new
plants for the first time, including genome structure, GC content, repeat structure, codon usage, nucleotide diversity and etc. The entire length of the
chloroplast genome ranged from 167,975 to 172,653 bp, including 113 distinct genes comprising 79 protein-coding genes, 30 transfer RNA (tRNA) genes and four ribosomal RNA (rRNA) genes. In comparative analysis, we found that the contraction and expansion of the inverted repeat (IR) regions resulted in the doubling of the
gene. The several non-coding sites (
, and
) and three genes (
, and
) showed significant variation, indicating that they have the potential of molecular markers. Phylogenetic analysis based on the complete chloroplast genome and coding sequences of 77 protein-coding genes confirmed that
can be mainly divided into two groups. These genomic sequences provide molecular foundation for the development and utilization of
plants resources. This result may contribute to the understanding of the evolution pattern, phylogenetic relationships as well as classification of
plants.
With the widespread development of distributed power generation technology, photovoltaic power generation has been widely used. Aiming at the past, the reactive power optimization algorithm with ...distributed photovoltaic access distribution network needs to convert the multi-objective problem into a single-objective solution process where the weight setting is not objective. This paper proposes a multi-objective optimization algorithm based on improved particle swarm optimization algorithm. The multi-objective model based on Pareto optimal solution is used to obtain the Pareto optimal solution set, and the optimal solution is selected from it. At the same time, the algorithm is improved, the external file is used to update the optimal position of the particle, the population diversity is increased to avoid premature problems, and the performance of the algorithm is improved by analyzing the test function. Through modeling, the influence of distributed photovoltaic power generation on the power grid is studied, and simulation is performed in the IEEE-33 node system. The simulation results prove the feasibility of the improved algorithm in this paper.
A unique design of a nickel nanocone‐arrays supported silicon anode is introduced for high‐power and long‐life lithium‐ion batteries. The nanostructured Si anodes show a high reversible capacity of ...around 2400 mAh g−1 (at 0.2C) and excellent cycling capability. They also exhibit an impressive high‐rate capability and stable capacities of up to 1700 mAh g−1 at 1C and 1300 mAh g−1 at 2C.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The aim of this study was to optimize pressure-assisted (PAE) parameters for using response surface methodology (RSM) and compare the chemical composition and characteristics of pepper (Capsicum ...annum L.) seed oil (PSO) by pressure-assisted, ultrasound-assisted (UAE) and conventional solvent extraction (CSE). The oil extraction efficiency extracted from the optimized extraction parameters (pressure 370 MPa, temperature 50 °C, and time 5.7 min) achieved the highest of 83.0%, and PSO by PAE could retain higher level of unsaturated fatty acids (82.36%), γ-tocopherol (8.04 mg/100 g), characterized with lower acid value (3.89 mg KOH/g), peroxide value (1.47 mmol/kg) and higher iodine value (130.80 gI/100 g), and displayed superior antioxidant capacity.
This research paper has not yet been discussed. The available data are provided for evaluation and application of PAE in oils extraction industry and PAE could be a more efficient and time-saving technique to extract higher quality for the commercial PSO production.
•Response surface method was applied for optimization of pressure-assisted extraction (PAE).•PAE is a more efficient and time-saving technique.•Pepper seed oil extracted by PAE had a better quality characters.•Pepper seed oil extracted by PAE displayed superior antioxidant capacity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As a pioneer in controlling vehicle emissions within China, Beijing released the Clean Air Action Plan 2013–2017 document in August 2013 to improve its urban air quality. It has put forward this plan ...containing the most stringent emission control policies and strategies to be adopted for on-road vehicles of Beijing. This paper estimates the historic and future trends and uncertainties in vehicle emissions of Beijing from 1998 to 2020 by applying a new emission factor model for the Beijing vehicle fleet (EMBEV). Our updated results show that total emissions of CO, THC, NOx and PM2.5 from the Beijing vehicle fleet are 507 (395–819) kt, 59.1 (41.2–90.5) kt, 74.7 (54.9–103.9) kt and 2.69 (1.91–4.17) kt, respectively, at a 95% confidence level. This represents significant reductions of 58%, 59%, 31% and 62%, respectively, relative to the total vehicle emissions in 1998. The past trends clearly posed a challenge to NOx emission mitigation for the Beijing vehicle fleet, especially in light of those increasing NOx emissions from heavy-duty diesel vehicles (HDDVs) which have partly offset the reduction benefit from light-duty gasoline vehicles (LDGVs). Because of recently announced vehicle emission controls to be adopted in Beijing, including tighter emissions standards, limitations on vehicle growth by more stringent license control, promotion of alternative fuel technologies (e.g., natural gas) and the scrappage of older vehicles, estimated vehicle emissions in Beijing will continue to be mitigated by 74% of CO, 68% of THC, 56% of NOx and 72% of PM2.5 in 2020 compared to 2010 levels. Considering that many of the megacities in China are facing tremendous pressures to mitigate emissions from on-road vehicles, our assessment will provide a timely case study of significance for policy-makers in China.
•We report two decades' trends and the uncertainties in vehicle emissions in Beijing.•Emission reduction for NOx is much more difficult than other three air pollutants.•The stringent control program can significantly reduce future vehicle emissions.•Traffic controls are playing an essential role in mitigating urban vehicle emissions.•Natural gas buses are required to relieve the NOx and PM2.5 burden for bus fleet.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this study, the surface enhanced Raman spectra (SERS) of two prohibited veterinary drugs, metronidazole (MNZ) and ronidazole (RNZ), have been acquired, and compared to the theoretically calculated ...spectra using density function theory (DFT). The experimental Raman and SERS spectra of MNZ and RNZ exhibit high resemblance with the DFT calculations. SERS detection of MNZ and RNZ from standard solutions as well as real environmental samples (tap, lake, swamp waters and soil) was performed on highly sensitive and reproducible silver nanorod array substrates. The limits of detection for MNZ and RNZ are 10 and 1µg/mL in methanol and ultra-pure water, respectively, and 10–50µg/mL in the environmental samples. The SERS-based method demonstrates its potential as a rapid, simple, and inexpensive means for the onsite screening of banned antibiotics from the aquatic and sediment environments, with minimal requirement for sample pretreatment.
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•The Raman and SERS spectra of metronidazole (MNZ) and ronidazole (RNZ) have been acquired.•Density function theory was used to predict theoretical spectra of MNZ and RNZ.•The limits of detection for MNZ and RNZ were determined.•SERS was used to detect MNZ and RNZ from environmental samples with minimal sample pre-treatment.
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•Chain structure and segment configuration are modified to tailor the performance of materials.•Block copolymers composed of PTMG and PLGA segments were well tailored.•Novel block ...copolymers exhibit desirable mechanical properties and controllable degradation rate.
The macroinitiator of poly(1,3-trimethylene carbonate-ran-glycolide) (P(TMC-ran-GA)) copolymers terminated with hydroxyl groups were synthesized by ring-opening polymerization (ROP) at 120 °C for 12 h. Then, the novel block copolymers consisting of P(TMC-ran-GA) segments bonding with L-lactide (LLA) and glycolide (GA) random copolymerization segments were prepared. The poly(TMC/GA-block-LLA/GA)) block copolymers were synthesized by ROP in bulk at 130 °C with high Mn¯(above 2.0 × 105 Da). Such kind of block copolymers composed of P(TMC-ran-GA) and P(LLA-ran-GA) segments show good mechanical properties and adjustable degradation rate. The molecular structures of block copolymers were characterized by GPC, FTIR, and 1H NMR. Chain microstructure analysis was performed in detail with 13C NMR spectroscopy. The effect of GA units content on thermal behaviors, mechanical properties as well as biodegradability of copolymers was investigated by DSC, XRD, stress-strain measurements and enzymatic degradation tested in comparison with corresponding block copolymers P(TMC-block-LLA/GA). The results shown that amorphous P(TMC-ran-GA) segments significantly improve the flexibility of block copolymers. The incorporation of GA units strongly decreases the crystallization ability of LLA segment within copolymers due to more random LLA-GA sequence and shorter average LLA block length. Meanwhile, the tensile strength of material and flexibility are significantly improved with the raising GA units content. The enzymatic degradation rate is also accelerated with the increase GA unit content. Thus, the biodegradable block copolymers with unique molecular structure and modifiable properties are promising new materials for biomedical applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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