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Nitrogen dioxide (NO2) at the ground level poses a serious threat to environmental quality and public health. This study developed a novel, artificial intelligence approach by integrating spatiotemporally weighted information into the missing extra-trees and deep forest models to first fill the satellite data gaps and increase data availability by 49% and then derive daily 1 km surface NO2 concentrations over mainland China with full spatial coverage (100%) for the period 2019-2020 by combining surface NO2 measurements, satellite tropospheric NO2 columns derived from TROPOMI and OMI, atmospheric reanalysis, and model simulations. Our daily surface NO2 estimates have an average out-of-sample (out-of-city) cross-validation coefficient of determination of 0.93 (0.71) and root-mean-square error of 4.89 (9.95) µg/m3. The daily seamless high-resolution and high-quality dataset "ChinaHighNO2" allows us to examine spatial patterns at fine scales such as the urban-rural contrast. We observed systematic large differences between urban and rural areas (28% on average) in surface NO2, especially in provincial capitals. Strong holiday effects were found, with average declines of 22 and 14% during the Spring Festival and the National Day in China, respectively. Unlike North America and Europe, there is little difference between weekdays and weekends (within ±1 µg/m3). During the COVID-19 pandemic, surface NO2 concentrations decreased considerably and then gradually returned to normal levels around the 72nd day after the Lunar New Year in China, which is about 3 weeks longer than the tropospheric NO2 column, implying that the former can better represent the changes in NOx emissions.
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Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Inteligencia Artificial , China , Monitoreo del Ambiente , Humanos , Dióxido de Nitrógeno/análisis , PandemiasRESUMEN
The research on SO2 pollution in China has been hotly debated over the past decades. Different from the existing studies, this work employs satellite observed SO2 columns from 2005 to 2016 and applies a spatial econometric approach to investigate the socio-economic influencing factors of SO2 pollution of 270 prefecture-level cities in China. The findings are as follows. (1) SO2 pollution over China exhibits a significant and positive spatial autocorrelation. (2) The most polluted area is concentrated on the North China Plain. However, SO2 pollution over China has been reduced gradually during the sample period, implying that overall environmental quality in China has been substantially improved. (3) Besides, the results of spatial econometric models are not in support of "pollution haven hypothesis". On the contrary, the pollution halo effect of foreign direct investment works well and contributes to reducing SO2 pollution in China. Moreover, we find that urban economic levels and innovative capability are negatively correlated with SO2 pollution, indicating that economic growth and an increase in innovation can help improve environmental quality. On contrast, the share of the secondary industry, urbanization and transportation are found to have positive impacts, indicating that they are three main contributors to SO2 pollution in China.
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Contaminantes Atmosféricos , Contaminación del Aire , China , Ciudades , Monitoreo del Ambiente , Contaminación Ambiental , Material Particulado , Factores Socioeconómicos , Análisis EspacialRESUMEN
Ionic porous organic polymers have attracted much attention due to their broad applications in catalysis, energy storage/conversion, proton conduction, etc. In this paper, an ionic porous organic polymer, CMP-PM-Me, was synthesized through post-synthetic modification of a pyrimidine-based conjugated microporous polymer, CMP-PM, which was constructed by the palladium catalyzed Sonogashira reaction of 1,3,5-triethynylbenzen and 2,5-dibromopyrimidine. These two polymers are porous with Brunauer-Emmett-Teller surface areas of 416 and 241â m2 g-1 for CMP-PM and CMP-PM-Me, respectively. Due to the cationic framework, CMP-PM-Me exhibits a much faster and more efficient adsorption performance to anionic dyes such as Congo red (CR) and methyl orange (MO) than that of CMP-PM with a neutral framework. The uptakes for CR are 400.0â mg g-1 for CMP-PM-Me and 344.8â mg g-1 for CMP-PM, respectively. Furthermore, CMP-PM-Me could quickly and drastically separate anionic dyes from the binary mixed solution of anionic and nonanionic dyes within a short time. This work not only enriches the family of ionic organic porous polymers and widens their synthetic utility, but also demonstrates their applications in the adsorption and separation of anionic dyes in water.
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Multifunctional Fe3O4@SiO2-Au@silicalite-1 core-shell magnetic zeolite composites were fabricated by combining a series of sol-gel process and vapor-phase transfer of silicalite-1 zeolite nanocrystal-seeded silica shells. The obtained composite has high magnetization (32.00 emu/g), stably confined and active gold nanoparticles (ca. 15 nm), and a hierarchical silicalite-1 outer shell. The core-shell composite exhibits a high efficiency of magnetic separability, excellent catalytic performance, and reusability for the reduction of 4-nitrophenol with conversion of 98% in 12 min. Moreover, it preserves a good stability after a high-temperature hydrothermal treatment.
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China's rapid economic growth in recent decades has caused a growing problem of environmental pollution, which negatively impacts the physical and mental health of residents. In recent years, renewable energy has emerged as a promising solution to alleviate environmental pollution and improve residents' well-being. However, it is unknown whether renewable energy development can counterbalance the health impacts of environmental pollution. Therefore, we conducted a study using data from the China Family Panel Studies (CFPS) to examine the impact of environmental pollution and renewable energy on the health of 20,694 residents. Our analysis showed that renewable energy development can partially offset the negative health effects of environmental pollution. Specifically, we found that a 1% increase in environmental pollution is linked to an average decrease of 0.0911% in physical health (PHY) and 0.0566% in mental health (MEN), whereas each 1% rise in renewable energy corresponds to an average increase of 0.2585% in PHY and 0.1847% in MEN. These positive effects apply to male and female residents, urban and rural residents, young and middle-aged adults, and people with low, medium, and high levels of education. These findings are significant for decision-makers striving to improve Chinese residents' physical and mental health by considering the specific impact of renewable energy and comprehensive environmental pollution.
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Contaminación Ambiental , Salud Mental , Adulto , Persona de Mediana Edad , Humanos , Masculino , Femenino , China , Energía Renovable , Desarrollo EconómicoRESUMEN
To recover the global economy, China in 2013 called for a new global strategy, namely, "One Belt and One Road Initiative" (BRI), which aims at reinforcing regional economic cooperation, enhancing regional collaboration of economic policy, and realizing the goal of rapid economic development of member countries. Accelerating industrialization not only has been recognized as an effective way to stimulate economic development, but also lead to the serious issue of environmental pollution, which challenges the environmental sustainability. In this study, we focus on the industrializing region as a study area to investigate the driving factors of environmental pollution. Technically, we utilized satellite observation technique to obtain NO2 columns data to denote environmental pollution and then applied dynamic spatial panel data models to evaluate what affects NO2 pollution levels. The findings are the following. (1) NO2 pollution exhibits significant and positive spatial autocorrelation, indicating spatial spillovers of NO2 pollution. (2) Lebanon, Bangladesh, Kyrgyzstan, and India experienced the largest increase of NO2 pollution while NO2 pollution in Singapore, Hungary, Greece, and Ukraine was substantially reduced. (3) The results of the dynamic spatial panel data models show that both the time dynamics effects and the spatial spillover effects are found to be significant and positive. In other words, both effects should be considered. Population is the foremost contributor to increase NO2 pollution while urbanization is an effective way to reduce pollution. An EKC relationship between NO2 pollution and per capita income was verified. Besides, industrialization, foreign direct investment, and trade openness have positive impacts on NO2 pollution.
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Análisis de Datos , Dióxido de Nitrógeno , Bangladesh , China , Desarrollo Económico , Contaminación Ambiental , Grecia , Hungría , India , Kirguistán , Líbano , Singapur , Análisis Espacial , UcraniaRESUMEN
The slow kinetics of oxygen evolution reaction (OER) causes high power consumption for electrochemical water splitting. Various strategies have been attempted to accelerate the OER rate, but there are few studies on regulating the transport of reactants especially under large current densities when the mass transfer factor dominates the evolution reactions. Herein, Nix Fe1- x alloy nanocones arrays (with ≈2 nm surface NiO/NiFe(OH)2 layer) are adopted to boost the transport of reactants. Finite element analysis suggests that the high-curvature tips can enhance the local electric field, which induces an order of magnitude higher concentration of hydroxide ions (OH- ) at the active sites and promotes intrinsic OER activity by 67% at 1.5 V. Experimental results show that a fabricated NiFe nanocone array electrode, with optimized alloy composition, has a small overpotential of 190 mV at 10 mA cm-2 and 255 mV at 500 mA cm-2 . When calibrated by electrochemical surface area, the nanocones electrode outperforms the state-of-the-art OER electrocatalysts. The positive effect of the tip-enhanced local electric field in promoting mass transfer is also confirmed by comparing samples with different tip curvature radii. It is suggested that this local field enhanced OER kinetics is a generic effect to other OER catalysts.
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Manganese dioxide (MnO2) with a conversion mechanism is regarded as a promising anode material for lithium-ion batteries (LIBs) owing to its high theoretical capacity (â¼1223 mA h g-1) and environmental benignity as well as low cost. However, it suffers from insufficient rate capability and poor cyclic stability. To circumvent this obstacle, semiconducting polypyrrole coated-δ-MnO2 nanosheet arrays on nickel foam (denoted as MnO2@PPy/NF) are prepared via hydrothermal growth of MnO2 followed by the electrodeposition of PPy on the anode in LIBs. The electrode with â¼50 nm thick PPy coating exhibits an outstanding overall electrochemical performance. Specifically, a high rate capability is obtained with â¼430 mA h g-1 of discharge capacity at a high current density of 2.67 A g-1 and more than 95% capacity is retained after over 120 cycles at a current rate of 0.86 A g-1. These high electrochemical performances are attributed to the special structure which shortens the ion diffusion pathway, accelerates charge transfer, and alleviates volume change in the charging/discharging process, suggesting a promising route for designing a conversion-type anode material for LIBs.
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One of the most concerning consequences arising from the dramatic urbanization in cities is air stagnation and the related high concentration of air pollutants. Many studies have investigated the impact of urbanization on air stagnation, but few have systematically evaluated such impact and its spatial-temporal variances at the municipal scale. This study proposed an approach based on high-resolution urban climate simulations for evaluating the impact of urbanization on air stagnation. We took the city of Shenzhen in south-eastern China, a city that grew from a small fishing and farming village to a highly urbanized city in the past thirty years, as a compelling case study. Using the WRF/Noah LSM/SLUCM model, we simulated and evaluated the probability of 6-hourly air stagnation cases (ASCs) in 1979 and 2010 at the spatial resolution of 1-km2 to demonstrate the change over a thirty-year period. Comparison results show that urbanization worsened the problem of air stagnation in Shenzhen. The number of 6-hourly ASCs has increased by 21,700 for the entire Shenzhen, and by 11.4 on average for each grid with a 1â¯km2 size. A maximum increase of 458 ASCs in a grid was also observed.
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China's rapid urbanization and industrialization have affected the spatiotemporal patterns of nitrogen dioxide (NO2) pollution, which has led to greater environmental pressures. In order to mitigate the environmental pressures caused by NO2 pollution, it is of vital importance to investigate the influencing factors. We first obtained data for NO2 pollution at the city level using satellite observation techniques and analyzed its spatial distribution. Next, we introduced a theoretical framework, an extended stochastic impacts by regression on population, affluence, and technology (STIRPAT) model, to quantify the relationship between NO2 pollution and its contributing natural and socio-economic factors. The results are as follows. Cities with high NO2 pollution are mainly concentrated in the North China Plain. On the contrary, southwestern cities are characterized by low NO2 pollution. In addition, we find that population, per capita gross domestic product, the share of the secondary industry, ambient air pressures, total nighttime light data, and urban road area have a positive impact on NO2 pollution. In contrast, increases in the normalized difference vegetation index (NDVI), relative humidity, temperature, and wind speed may reduce NO2 pollution. These empirical results should help the government to effectively and efficiently implement further emission reductions and energy saving policies in Chinese cities in a bid to mitigate the environmental pressures.
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Contaminantes Atmosféricos/análisis , Modelos Teóricos , Dióxido de Nitrógeno/análisis , Contaminación del Aire , China , Ciudades , Comunicaciones por Satélite , Urbanización , Tiempo (Meteorología)RESUMEN
In this paper, a series of bisbenzimidazole-functionalized highly porous covalent triazine frameworks (CTF-BIBs) has been constructed from a new organic building block, 1,4-bis(5-cyano-1 H-benzimidazole-2-yl)benzene, via ionothermal polymerization. The physical porosity and gas adsorption properties of these CTF-BIBs were characterized, and the resulting CTF-BIBs exhibit significantly high Brunauer-Emmett-Teller surface areas (1636-2088 m2 g-1) and notable CO2 uptakes (86.4-97.6 cm3 g-1 at 273 K and 1 bar; 48.5-56.8 cm3 g-1 at 298 K and 1 bar). More importantly, these CTF-BIBs exhibit excellent selective separation abilities for CO2/N2, CO2/CH4, C2H6/CH4, and C3H8/CH4, particularly for equimolar mixtures C3H8/CH4 (386.6 for CTF-BIB-1 under 1 bar and 298 K). Furthermore, transient breakthrough simulations were carried out for equimolar CO2/C3H8/C2H6/CH4 mixtures, and CTF-BIBs display good separation performance in industrial fixed bed adsorbers. These results clearly demonstrate that the synthesized CTF-BIBs may serve as potential materials for CO2 capture and adsorptive separation for small hydrocarbons.
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A novel multifunctional drug delivery system has been constructed by assembling per-6-thio-ß-cyclodextrin-modified ultrasmall CuS nanoparticles (CD-CuS) onto fluorescent AIEgen-containing mesoporous silica nanoparticles (FMSN). The CD-CuS nanoparticles are anchored on the surface of benzimidazole-grafted FMSN, acting as a gatekeeper and photothermal agent. The prepared blue-emitting nanocomposite (FMSN@CuS) exhibits good biocompatibility and cell imaging capability. Anticancer drug doxorubicin hydrochloride (DOX) molecules are loaded into FMSN@CuS, and zero prerelease at physiological pH (7.4) and on-demand drug release at an acidic environment can be achieved due to the pH-responsive gate-opening of CD-CuS only at an acidic condition. The FMSN@CuS nanocomposite can generate obvious thermal effect after the exposure of 808 nm laser, which can also accelerate the DOX release. Meanwhile, the fluorescence intensity of DOX-loaded FMSN@CuS increases with the release of DOX, and the intracellular drug release process can be tracked according to the change of luminescence intensity. More importantly, DOX-loaded FMSN@CuS displays efficient anticancer effects in vitro upon 808 nm laser irradiation, demonstrating a good synergistic therapeutic effect via combining enhanced chemotherapy and photothermal therapy.
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Dióxido de Silicio/química , Cobre , Ciclodextrinas , Doxorrubicina , Humanos , Hipertermia Inducida , Nanopartículas , Neoplasias , FototerapiaRESUMEN
Mg, Co-substituted aluminophosphate zeolites with ERI framework topology (denoted as MgAPO-ERI and CoAPO-ERI) have been synthesized under hydrothermal conditions by using N, N, N', N'-tetramethyl-1,6-hexanediamine as organic template. Their CO2 adsorption properties are investigated in comparison to those of the pure aluminophosphate counterpart AlPO-ERI. CoAPO-ERI shows the highest CO2 uptake of 57.3 cm3 g-1 (273 K and 1 bar) and the highest isosteric heat of 39.0 kJ mol-1 among the three samples. Importantly, the incorporation of Mg2+ and Co2+ ions in the framework of AlPO-ERI can greatly improve the adsorption selectivities of CO2 over CH4 and N2. Whereafter, transient breakthrough simulations were investigated and further proved the advantages of heteroatoms for separations. These results demonstrate that isomorphous heteroatom substitutions in aluminophosphate zeolites play a key role in enhancing CO2 adsorption and separation abilities.