Aerosols Monitored by Satellite Remote Sensing

Aerosols, small particles suspended in the atmosphere, affect the air quality and climate change. Their distributions can be monitored by satellite remote sensing. Many images of aerosol properties are available from websites as the by-products of the atmospheric correction of the satellite data. Their qualities depend on the accuracy of the atmospheric correction algorithms. The approaches of the atmospheric correction for land and ocean are different due to the large difference of the ground reflectance between land and ocean. A unified atmospheric correction (UAC) approach is developed to improve the accuracy of aerosol products over land, similar to those over ocean. This approach is developed to estimate the aerosol scattering reflectance from satellite data based on a lookup table (LUT) of in situ measured ground reflectance. The results show that the aerosol scattering reflectance can be completely separated from the satellite measured radiance over turbid waters and lands. The accuracy is validated with the mean relative errors of 22.1%. The vertical structures of the aerosols provide a new insight into the role of aerosols in regulating Earth\u27s weather, climate, and air quality

Influence of shear on polypropylene crystallization kinetics

Isothermal crystallization kinetics under shear in the melt of iPP was investigated by optical microscopy. It appears that shearing from 200 to the crystallization temperatures enhanced the kinetics, but the shear effect was not obvious if the melt of iPP was sheared only at 200. The experiment results show that relaxation plays an important role during crystallization, and that spherulite growth rates increased with shear rates and were governed by relaxation. The effect of flow on the crystallization kinetics can be understood by considering that the increase of the degree of order due to flow results is an effective change of the melt free energy. The Laurizen-Hoffman theory and the DE-IAA model were used to describe the shear-induced crystallization kinetics of iPP excellently

Trends of Planetary Boundary Layer Height Over Urban Cities of China From 1980–2018

Publisher Copyright: © Copyright © 2021 Huo, Wang, Paasonen, Liu, Tang, Ma, Petaja, Kerminen and Kulmala.Boundary layer height (BLH) is an important parameter in climatology and air pollution research, especially in urban city. We calculated the BLH with a bulk Richardson number (Ri) method over urban cities of China during 1980–2018 using European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-interim data after carefully validation with sounding data obtained from two meteorology stations in eastern China during 2010–2018. The values of BLH between these two types of data have correlation coefficients in the range of 0.65–0.87, which indicates that it is reasonable to analyze long-term trends of the BLH from ERA data sets. Using ERA-interim calculated BLH, we found that there is an increasing trend in the daytime BLH in most cities of eastern China, particularly during the spring season. A correlation analysis between the BLH and temperature, wind speed, relative humidity and visibility revealed that the variability in meteorological parameters, as well as in aerosol concentrations over highly polluted eastern China, play important roles in the development of the BLH.Peer reviewe

New Deep Learning Model to Estimate Ozone Concentrations Found Worrying Exposure Level over Eastern China

Ozone (O3), whose concentrations have been increasing in eastern China recently, plays a key role in human health, biodiversity, and climate change. Accurate information about the spatiotemporal distribution of O3 is crucial for human exposure studies. We developed a deep learning model based on a long short-term memory (LSTM) network to estimate the daily maximum 8 h average (MDA8) O3 across eastern China in 2020. The proposed model combines LSTM with an attentional mechanism and residual connection structure. The model employed total O3 column product from the Tropospheric Monitoring Instrument, meteorological data, and other covariates as inputs. Then, the estimates from our model were compared with real observations of the China air quality monitoring network. The results indicated that our model performed better than other traditional models, such as the random forest model and deep neural network. The sample-based cross-validation R2 and RMSE of our model were 0.94 and 10.64 μg m−3, respectively. Based on the O3 distribution over eastern China derived from the model, we found that people in this region suffered from excessive O3 exposure. Approximately 81% of the population in eastern China was exposed to MDA8 O3 > 100 μg m−3 for more than 150 days in 2020

Data from: Prevalence and causes of anaemia in children aged 6-23 months in rural Qinghai, China: findings from a cross-sectional study

Objective: To investigate the current situation of anaemia among children aged 6-23 months in a rural county in China, and to explore the influencing factors and the main causes of anaemia. Design: A cross-sectional study. Setting: Huzhu County in Qinghai Province, China. Participants: We selected 38 sampled villages using Proportional to Population Size sampling method. We obtained the name list of children aged 6-23 months in each sampled village and planned to survey all the eligible children aged 6-23 months and their caregivers. Primary and secondary outcomes measures: The prevalence of anaemia, the influencing factors of anaemia, the laboratory tests for biological causes of anaemia, including serum ferritin, sTfR, folic acid, Homocysteine and Vitamin B12. Results: A total of 754 children aged 6-23 months and their caregivers were surveyed, and 183 anaemic children aged 12-23 months were collected venous blood sample. The anaemia prevalence of children aged 6-23 months in Huzhu County was 59.1%. Children of younger age (OR=0.968, 95%CI 0.940, 0.998), Tibetan nationality (OR=3.123, 95%CI 1.473,6.623) and not introducing meat (OR=0.698, 95%CI 0.499,0.976) were more likely to be anaemic. More than 80% of children with anaemia were due to iron deficiency, and 20.2% of them had both iron and folic acid deficiencies. Conclusions: The anaemia prevalence of children aged 6-23 months in Huzhu County was high and children of younger age, Tibetan nationality and not introducing meat were more likely to be anaemic. The main cause of anaemia was nutritional anaemia, with the vast majority being iron deficiency. Interventions of feeding counseling and nutrients supplements are appropriate and should be further strengthened

PREPARATION AND CHARACTERIZATION OF SUPER-HYDROPHOBIC SURFACES ON ALUMINUM AND STAINLESS STEEL SUBSTRATES

Hierarchical alveolate structures in nano- to microscale were fabricated on both aluminum and stainless steel substrates via a chemical etching. On aluminum surfaces, sharp edged caves and plateaus were found. On stainless steel substrate, fine papillae stand on protuberances. These surfaces exhibit super-hydrophobic properties after the fluorination treatment, their water contact angles are 158° and 160°, respectively, with the contact angle hysteresis of about 5°. The roll off angle is about 5°. Ice melting behaviors on a plate of aluminum super-hydrophobic surface were compared with those on a hydrophilic one, their difference shows that the new feature of super-hydrophobic surface could be expected.Super-hydrophobicity, chemical etching, micro- and nanostructure, aluminum, stainless steel

Retrieval of surface PM2.5 mass concentrations over North China using visibility measurements and GEOS-Chem simulations

Despite much effort made in studying human health associated with fine particulate matter (PM2.5), our knowledge about PM2.5 and human health from a long-term perspective is still limited by inadequately long data. Here, we presented a novel method to retrieve surface PM2.5 mass concentrations using surface visibility measurements and GEOS-Chem model simulations. First, we used visibility measurements and the ratio of PM2.5 and aerosol extinction coefficient (AEC) in GEOS-Chem to calculate visibility-inferred PM2.5 at individual stations (SC-PM2.5). Then we merged SC-PM2.5 with the spatial pattern of GEOS-Chem modeled PM2.5 to obtain a gridded PM2.5 dataset (GC-PM2.5). We validated the GC-PM2.5 data over the North China Plain on a 0.3125° longitude x 0.25° latitude grid in January, April, July and October 2014, using ground-based PM2.5 measurements. The spatial patterns of temporally averaged PM2.5 mass concentrations are consistent between GC-PM2.5 and measured data with a correlation coefficient of 0.79 and a linear regression slope of 0.8. The spatial average GC-PM2.5 data reproduce the day-to-day variation of observed PM2.5 concentrations with a correlation coefficient of 0.96 and a slope of 1.0. The mean bias is less than 12 μg/m3 (<14%). Future research will validate the proposed method using multi-year data, for purpose of studying long-term PM2.5 variations and their health impacts since 1980.Peer reviewe

Discovery of the relationship between bitter taste and bitter flavor (efficacy) based on hTAS2Rs

Objective: To explore the relationship between bitter taste and bitter flavor (efficacy), their characteristics were analyzed at the target and pharmacodynamic points. Methods: Compounds with bitter receptor activity were obtained by high-throughput screening models of the human bitter taste receptors (hTAS2Rs), which were used to analyze bitter taste. The efficacy of anti-asthma medications was used as an example to research bitter flavor (efficacy). The pharmacological effects of bitter taste and bitter flavor (efficacy) were classified according to the functional modules. The coverage for the same targets or pharmacological effects in the overall protein interaction network (PIN) of bitter taste and bitter flavor (efficacy) was analyzed to reveal their relationship. The effect of the compound polydatin with anti-asthma activation on hTAS2R14 was studied to verify the reliability of the aforementioned idea. Results: A total of 121 Chinese materia medica (CMM) compounds that activate hTAS2R10, hTAS2R14, and hTAS2R49 were obtained. The analysis results indicated that 108 same targets for bitter taste and bitter flavor (efficacy) were obtained, accounting for 13.9% in the PIN of bitter taste and 72.5% in the PIN of bitter flavor (efficacy). The pharmacological effects shared by bitter taste and bitter flavor (efficacy) accounted for 79% of the PIN of bitter taste and 81% of the PIN of bitter flavor (efficacy). The activating effect of the anti-asthma compound polydatin on hTAS2R14 was dose-dependent with EC50 of 4.3 μM. Conclusion: In this study, the relationship between bitter taste and bitter flavor (efficacy) has been demonstrated from the target and pharmacodynamic points, which are based on hTAS2Rs and anti-asthma effect. Bitter taste and bitter flavor (efficacy) exhibited a high correlation. This study provides a theoretical and scientific basis for the hypothesis that “the property theory of CMM is the clinical pharmacodynamics of CMM.