Exploring the spatial effects and influencing mechanism of ozone concentration in the Yangtze River Delta urban agglomerations of China.

Ground-level ozone (O3) pollution has emerged as a significant concern impacting air quality in urban agglomerations, primarily driven by meteorological conditions and social-economic factors. However, previous studies have neglected to comprehensively reveal the spatial distribution and driving mechanism of O3 pollution. Based on the O3 monitoring data of 41 cities in the Yangtze River Delta (YRD) from 2014 to 2021, a comprehensive analysis framework of spatial analysis-spatial econometric regression was constructed to reveal the driving mechanism of O3 pollution. The results revealed the following: (1) O3 concentrations in the YRD exhibited a general increasing and then decreasing trend, indicating an improvement in pollution levels. The areas with higher O3 concentration are mainly the cities concentrated in central and southern Jiangsu, Shanghai, and northern Zhejiang. (2) The change of O3 concentration and distribution is the result of various factors. The effect of urbanization on O3 concentrations followed an inverted U-shaped curve, which implies that achieving higher quality urbanization is essential for effectively controlling urban O3 pollution. Traffic conditions and energy consumption have significant direct positive influences on O3 concentrations and spatial spillover effects. The indirect pollution contribution, considering economic weight, accounted for about 35%. Thus, addressing overall regional energy consumption and implementing traffic source regulations are crucial paths for O3 pollution control in the YRD. (3) Meteorological conditions play a certain role in regulating the O3 concentration. Higher wind speed will promote the diffusion of O3 and increase the O3 concentration in the surrounding city. These findings provide valuable insights for designing effective policies to improve air quality and mitigate ozone pollution in urban agglomeration area.

Roles of MEM1 in safeguarding Arabidopsis genome against DNA damage, inhibiting ATM/SOG1-mediated DNA damage response, and antagonizing global DNA hypermethylation.

Arabidopsis methylation elevated mutant 1 (mem1) mutants have elevated levels of global DNA methylation. In this study, such mutant alleles showed increased sensitivity to methyl methanesulfonate (MMS). In mem1 mutants, an assortment of genes engaged in DNA damage response (DDR), especially DNA-repair-associated genes, were largely upregulated without MMS treatment, suggestive of activation of the DDR pathway in them. Following MMS treatment, expression levels of multiple DNA-repair-associated genes in mem1 mutants were generally lower than in Col-0 plants, which accounted for the MMS-sensitive phenotype of the mem1 mutants. A group of DNA methylation pathway genes were upregulated in mem1 mutants under non-MMS-treated conditions, causing elevated global DNA methylation, especially in RNA-directed DNA methylation (RdDM)-targeted regions. Moreover, MEM1 seemed to help ATAXIA-TELANGIECTASIA MUTATED (ATM) and/or SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1) to fully activate/suppress transcription of a subset of genes regulated simultaneously by MEM1 and ATM and/or SOG1, because expression of such genes decreased/increased consistently in mem1 and atm and/or sog1 mutants, but the decreases/increases in the mem1 mutants were not as dramatic as in the atm and/or sog1 mutants. Thus, our studies reveals roles of MEM1 in safeguarding genome, and interrelationships among DNA damage, activation of DDR, DNA methylation/demethylation, and DNA repair.

Increased Drought Resistance 1 Mutation Increases Drought Tolerance of Upland Rice by Altering Physiological and Morphological Traits and Limiting ROS Levels.

To discover new mutants conferring enhanced tolerance to drought stress, we screened a mutagenized upland rice (Oryza sativa) population (cv. IAPAR9) and identified a mutant, named idr1-1 (increased drought resistance 1-1), with obviously increased drought tolerance under upland field conditions. The idr1-1 mutant possessed a significantly enhanced ability to tolerate high-drought stresses. Map-based cloning revealed that the gene LOC_Os05g26890, residing in the mapping region of IDR1 locus, carried a single-base deletion in the idr1-1 mutant. IDR1 encodes the Gα subunit of the heterotrimeric G protein (also known as RGA1), and this protein was localized in nucleus and to plasma membrane or cell periphery. Further investigations indicated that the significantly increased drought tolerance in idr1-1 mutants stemmed from a range of physiological and morphological changes, including greater leaf potentials, increased proline contents, heightened leaf thickness and upregulation of antioxidant-synthesizing and drought-induced genes, under drought-stressed conditions. Especially, reactive oxygen species (ROS) production might be remarkably impaired, while ROS-scavenging ability appeared to be markedly enhanced due to significantly elevated expression of ROS-scavenging enzyme genes in idr1-1 mutants under drought-stressed conditions. In addition, idr1-1 mutants showed reduced expression of OsBRD1. Altogether, these results suggest that mutation of IDR1 leads to alterations in multiple layers of regulations, which ultimately leads to changes in the physiological and morphological traits and limiting of ROS levels, and thereby confers obviously increased drought tolerance to the idr1-1 mutant.

Development of a Laser Gas Analyzer for Fast CO2 and H2O Flux Measurements Utilizing Derivative Absorption Spectroscopy at a 100 Hz Data Rate.

We report the development of a laser gas analyzer that measures gas concentrations at a data rate of 100 Hz. This fast data rate helps eddy covariance calculations for gas fluxes in turbulent high wind speed environments. The laser gas analyzer is based on derivative laser absorption spectroscopy and set for measurements of water vapor (H2O, at wavelength ~1392 nm) and carbon dioxide (CO2, at ~2004 nm). This instrument, in combination with an ultrasonic anemometer, has been tested experimentally in both marine and terrestrial environments. First, we compared the accuracy of results between the laser gas analyzer and a high-quality commercial instrument with a max data rate of 20 Hz. We then analyzed and compared the correlation of H2O flux results at data rates of 100 Hz and 20 Hz in both high and low wind speeds to verify the contribution of high frequency components. The measurement results show that the contribution of 100 Hz data rate to flux calculations is about 11% compared to that measured with 20 Hz data rate, in an environment with wind speed of ~10 m/s. Therefore, it shows that the laser gas analyzer with high detection frequency is more suitable for measurements in high wind speed environments.

Study on the Method of Voigt Profiles Two Wings Fitting Non-Uniform Flow Field Absorbance.

In the field of the absorption spectrum, especially for direct tunable diode laser absorption spectroscopy (dTDLAS) technology, the integrated area of the absorption spectrum is needed to be measured accurately for calculating the temperature and the component concentration of the flow field. Doing single optical path absorption spectroscopic measurement in the non-uniform flow field, spectral lineshape broadening is varied with the flow changes, in previous research reports, researchers mainly use single Voigt or Lorentz profile to fit absorbance curve or use directly integral to obtain the integrated area of the absorption spectrum. There are some shortcomings in these methods, resulting in certain error between the fitting result and the actual area, which is not conducive to the accurate measurement of flow field parameters. Firstly, the error is analyzed theoretically, and then, we adopt the simulation method to obtain the error size of the method. Finally, we proposed the Voigt wings fitting absorbance method to reduce the fitting error. The operation of Voigt wings fitting method is to Select the wings of the spectral line, and then use Voigt profile fitting, The difference between the two wings was used the numerical integral method to calculate area, the integrated area is sum of Voigt profile fitting area and numerical integral area. We have used water vapor as the target gas, with eight absorption lines which have different low-level states energy from HITRAN 2012 database being selected-, building two kinds of non-uniform flow field model base on the flat flame furnace, and through the method of segmentation to equivalent processing the no uniformity of flow field. Using Voigt profile fitting method, numerical integral method and Voigt profile wings fitting method to obtain the integral area of models, the error size is obtained by comparing with the theoretical value. As the result of contrast, the fitting error of Voigt profile fitting method is large and related to the different absorption line, the error of numerical integral method is biggest but it is nothing to do with absorption line, the fitting error of Voigt profile wings fitting method is least and stable. By force of contrast, we determined the appropriate method to obtain integral area in the different non-uniform flow field, which is beneficial to obtain accurate integrated area and flow field parameters.

[Reconstruction Research for Gas Concentration and Temperature of Flame Based on Algebraic Reconstruction Technique].

We specify water vapor among combustion products as the target gas based on tunable diode absorption spectroscopy in this paper. The direct absorption signals of water vapor after being processed can be used to calculate the gas concentration distributions and temperature distributions of the combustion region of methane and air flat flame furnace via algebraic reconstruction technique (ART). In the numerical simulation, reconstruction region is a grid of five by five, we assume a temperature and water vapor concentration distribution of 25 grid, then simulate different direction laser rays which cross the combustion region, generating projection of each ray, by ART reconstruction algorithm, it turns out that the temperature and water vapor distribution reconstruction error is less than 1%. In the experiment, we chose a distributed-feedback laser to scan the target gas H2O7 153.722, 7 153.748 and 7 154.354 cm(-1) as absorbtion line pair to measure temperature of the flame, we consider the former two line as one absorbtion line. By Stages multi-directional scanning, the authors abtain 16 different regions distributin of temperature and gas concentration of furnace when we collecte 30 different angle data by spectral data processing, reconstruction algorithm, two absorbtion line ratio method for temperature sensing, finding the temperature and water concentration are higher in the center than in the edge, it turns out that the reconstruction algorithm is good enough to achieve the distributions of gas concentration and temperature of the combustion region.

The impact of technological progress on China's haze pollution-based on decomposition and rebound research.

In order to effectively analyze and explore the socio-economic impact of haze pollution, the article constructs a comprehensive two-stage decomposition model to verify that technological progress plays a key role in controlling haze pollution. And for the first time, a macro-level research framework for the rebound effect of haze pollution has been constructed to compare and analyze the heterogeneity of the rebound effect of technological progress in different industries in different regions. The study found that (1) during the period 2000-2017, haze pollution situation deteriorated. Economic effects were the main reasons for haze pollution. Among these effects, technological progress was the main driving force for haze control, followed by the emission intensity during 2000-2011 and the reduction of industrial structure since 2014. (2) The significant drive of emission reduction is in the secondary industry, showing a trend of first increasing and then decreasing. Besides, there was a difference in spatial distribution, which shows an increased trend from east to west. (3) The rebound effect of haze pollution at the macro level in China presented high-level fluctuations, and there were certain spatial distribution differences. However, due to the convergence of technological development stages, regional differences have a gradual convergence trend. In the future, in the process of haze control, it is necessary to increase support for technological innovation, implement energy total control and price reform, promote technological progress, and implement differentiated haze reduction policies to solve problems according to local conditions.

Organic Photovoltaics Printed via Sheet Electrospray Enabled by Quadrupole Electrodes.

Developing manufacturing methods that are scalable and compatible with a roll-to-roll process with low waste of material has become a pressing need to transfer organic photovoltaics (OPVs) to a viable renewable energy source. For this purpose, various spray printing methods have been proposed. Among them, electrospray (ES) is an attractive option due to its negligible material waste, tunable droplet size, and tolerance to the substrate defects and roughness. Conventional ES with a circular spray footprint often makes the droplets well separated and unlikely to merge, giving rise to "coffee rings" which cause a rough and flawed film morphology. Here, a quadrupole electrode is introduced to generate a compressing electric field that squeezes the conical ES profile into the shape of a thin sheet. The numerical simulation and experimental data of the trajectories of sprayed droplets show that the quadrupole apparatus can effectively increase the long axis to short axis ratio of the oval spray footprint and hence bring droplets closer to each other and make the merging more likely for the deposited droplets. By promoting the merging of droplets, individual coffee rings are also suppressed. Thus, the quadrupole ES offers untapped opportunities for effectively reducing voids and improving the flatness of the ES-printed active layer. The devices with a PM6:N3 active layer printed by the sheet ES exhibited the highest power conversion efficiency (PCE) of up to 15.98%, which is a noticeable improvement over that (14.85%) of counterparts fabricated by a conventional conical ES. This is the highest PCE reported for ES-printed OPVs and is one of the most efficient spray-deposited OPVs so far. In addition, the all-spray-printed devices reached a PCE of 14.55%, which is also among the most efficient all-spray-printed OPVs.

Socioeconomic factors of industrial air pollutants in Zhejiang Province, China: Decoupling and Decomposition analysis.

In order to analyze and control air pollutant emissions effectively, on the basis of comprehensive consideration of three different pollution sources of industrial sulfur dioxide, industrial nitrogen oxides, and industrial smoke and dust, the Tapio decoupling model and LMDI decomposition model with six decomposition variables are constructed to compare the effects of socioeconomic factors on industrial air pollutant emissions in 11 cities in Zhejiang Province during 2006-2017. Then, a decoupling effort model is developed to analyze the effectiveness of the decoupling efforts taken at city level. This study found that (1) during the period of 2006-2017, the air pollutant emission reduction work in Zhejiang Province achieved remarkable results. More specifically, economic scale effect and population effect are the main factors for the increase of air pollutant emissions. And, the energy emission intensity effect and technological progress are the main driving forces for the reduction of three atmospheric pollutants, followed by the reduction effect of industrial structure and energy structure. (2) The environmental pollution problems of different air pollution sources in different cities are heterogeneous. (3) Eleven cities in Zhejiang Province have made significant decoupling efforts on the emission of three kinds of air pollutants, but there are some differences in the trend of the decoupling effort index of different pollution sources in different cities. In the future, illustrating by the example of Zhejiang, we should implement a "common but different" emission reduction strategy and emphasize pollutant emissions control during energy use in the efforts of further promoting the reduction of air pollutants.

[Characteristics of Atmospheric BTX near a Main Road in Hefei City].

In order to study levels of BTX near a main road in Hefei in March 2016, benzene, toluene, m-xylene, and o-xylene (BTX) and conventional pollutants (such as NO2 and SO2) in the atmosphere were monitored through a home-made differential optical absorption spectroscopy (DOAS) system. Results showed that average concentrations of benzene, toluene, m-xylene, and o-xylene were 21.7, 63.6, 33.9, and 98.7 µg·m-3, respectively. Compared with other cities both in China and elsewhere, benzene and toluene pollution can be considered to be of medium level, while xylene pollution is serious. Wind direction, T/B ratio, and correlation with CO were also analyzed, together with BTX sources. Result showed that the T/B ratio was 0.8-4.5, with correlation coefficients of benzene, toluene, and CO of 0.55 and 0.34, respectively. These values indicate that benzene and toluene are mainly derived from automotive emissions, also affected by surrounding industrial parks. Xylene is mainly derived from a coating industrial park north of the observation site. It was shown that high night-time concentrations of benzene and toulene could be due to industrial emissions from the industrial parks around the observation site. The ozone formation potential is in the order of o-xylene > m-xylene > toulene > benzene at the observation site. The ozone formation potential of xylene accounted for 85% of total ozone formation potential, indicating that emissions from surrounding industrial parks contribute greatly to ozone formation in the area.