Changes in factor profiles deriving from photochemical losses of volatile organic compounds: Insight from daytime and nighttime positive matrix factorization analyses.

Substantial effects of photochemical reaction losses of volatile organic compounds (VOCs) on factor profiles can be investigated by comparing the differences between daytime and nighttime dispersion-normalized VOC data resolved profiles. Hourly speciated VOC data measured in Shijiazhuang, China from May to September 2021 were used to conduct study. The mean VOC concentration in the daytime and at nighttime were 32.

GW3, encoding a member of the P450 subfamily, controls grain width by regulating the GA content in spikelets of rice (Oryza sativa L.).

A stable QTL, GW3, controlling grain width was identified in two populations. Its causal gene LOC_Os03g04680 was verified by gene-based haplotype analysis, expression analysis, gene knockout and complementation transgenic tests. Grain width (GW) is one of the key traits affecting grain size and determines grain yield and appearance quality in rice.

Enhancing Crop Resilience: Insights from Labdane-Related Diterpenoid Phytoalexin Research in Rice ( L.).

Rice ( L.), as one of the most significant food crops worldwide, holds paramount importance for global food security. Throughout its extensive evolutionary journey, rice has evolved a diverse array of defense mechanisms to fend off pest and disease infestations.

Optimizing BenMAP health impact assessment with meteorological factor driven machine learning models.

This study aims to address accuracy challenges in assessing air pollution health impacts using Environmental Benefits Mapping and Analysis Program (BenMap), caused by limited meteorological factor data and missing pollutant data. By employing data increment strategies and multiple machine learning models, this research explores the effects of data volume, time steps, and meteorological factors on model prediction performance using several years of data from Tianjin City as an example. The findings indicate that increasing training data volume enhances the performance of Random Forest Regressor (RF) and Decision Tree Regressor (DT) models, especially for predicting CO, NO, and PM.

Regime shift in secondary inorganic aerosol formation and nitrogen deposition in the rural United States.

Secondary inorganic aerosols play an important role in air pollution and climate change, and their formation modulates the atmospheric deposition of reactive nitrogen (including oxidized and reduced nitrogen), thus impacting the nitrogen cycle. Large-scale and long-term analyses of secondary inorganic aerosol formation based on model simulations have substantial uncertainties. Here we improve constraints on secondary inorganic aerosol formation using decade-long in situ observations of aerosol composition and gaseous precursors from multiple monitoring networks across the United States.

Hydrogen peroxide serves as pivotal fountainhead for aerosol aqueous sulfate formation from a global perspective.

Traditional atmospheric chemistry posits that sulfur dioxide (SO) can be oxidized to sulfate (SO) through aqueous-phase reactions in clouds and gas-phase oxidation. Despite adequate knowledge of traditional mechanisms, several studies have highlighted the potential for SO oxidation within aerosol water. Given the widespread presence of tropospheric aerosols, SO production through aqueous-phase oxidation in aerosol water could have a pervasive global impact.

Rapid hydrolysis of NO at High Ionic Strengths of Deliquesced Aerosol Particles.

Nitrogen dioxide (NO) hydrolysis in deliquesced aerosol particles forms nitrous acid and nitrate and thus impacts air quality, climate, and the nitrogen cycle. Traditionally, it is considered to proceed far too slowly in the atmosphere. However, the significance of this process is highly uncertain because kinetic studies have only been made in dilute aqueous solutions but not under high ionic strength conditions of the aerosol particles.

Atmospheric environment characteristic of severe dust storms and its impact on sulfate formation in downstream city.

This study comprehensively investigated the impact of dust storms (DSs) on downstream cities, by selecting representative DS events. In this paper, we discussed the characteristics of meteorological conditions, air pollutants, PM components, and their influence on sulfate formation mechanisms. During DSs, strong winds, reaching speeds of up to 10 m/s, led to significant increases in PM and PM, with maximum concentrations of 2684.

QTL Detection and Candidate Gene Identification for Eating and Cooking Quality Traits in Rice ( L.) via a Genome-Wide Association Study.

The eating and cooking quality (ECQ) directly affects the taste of rice, being closely related to factors such as gelatinization temperature (GT), gel consistency (GC) and amylose content (AC). Mining the quantitative trait loci (QTLs), and gene loci controlling ECQ-related traits is vital. A genome-wide association study on ECQ-related traits was conducted, combining 1.

Synthesizing evidence for the external cycling of NO in high- to low-NO atmospheres.

External cycling regenerating nitrogen oxides (NO ≡ NO + NO) from their oxidative reservoir, NO, is proposed to reshape the temporal-spatial distribution of NO and consequently hydroxyl radical (OH), the most important oxidant in the atmosphere. Here we verify the in situ external cycling of NO in various environments with nitrous acid (HONO) as an intermediate based on synthesized field evidence collected onboard aircraft platform at daytime. External cycling helps to reconcile stubborn underestimation on observed ratios of HONO/NO and NO/NO by current chemical model schemes and rationalize atypical diurnal concentration profiles of HONO and NO lacking noontime valleys specially observed in low-NO atmospheres.

Machine learning approaches reveal highly heterogeneous air quality co-benefits of the energy transition.

Estimating health benefits of reducing fossil fuel use from improved air quality provides important rationales for carbon emissions abatement. Simulating pollution concentration is a crucial step of the estimation, but traditional approaches often rely on complicated chemical transport models that require extensive expertise and computational resources. In this study, we develop a machine learning framework that is able to provide precise and robust annual average fine particle (PM) concentration estimations directly from a high-resolution fossil energy use dataset.

Source apportionment of consumed volatile organic compounds in the atmosphere.

Conventional source apportionments of ambient volatile organic compounds (VOCs) have been based on observed and initial concentrations after photochemical correction. However, these results have not been related to ozone (O) and secondary organic aerosol (SOA) formation. Thus, the apportioned contributions could not effectively support secondary pollution control development.

Changes in source apportioned VOCs during high O periods using initial VOC-concentration-dispersion normalized PMF.

Ambient volatile organic compounds (VOCs) concentrations are affected by emissions, dispersion, and chemistry. This work developed an initial concentration-dispersion normalized PMF (ICDN-PMF) to reflect the changes in source emissions. The effects of photochemical losses for VOC species were corrected by estimating the initial data, and then applying dispersion normalization to reduce the impacts of atmospheric dispersion.

Drivers of High Concentrations of Secondary Organic Aerosols in Northern China during the COVID-19 Lockdowns.

During the COVID-19 lockdown in early 2020, observations in Beijing indicate that secondary organic aerosol (SOA) concentrations increased despite substantial emission reduction, but the reasons are not fully explained. Here, we integrate the two-dimensional volatility basis set into a state-of-the-art chemical transport model, which unprecedentedly reproduces organic aerosol (OA) components resolved by the positive matrix factorization based on aerosol mass spectrometer observations. The model shows that, for Beijing, the emission reduction during the lockdown lowered primary organic aerosol (POA)/SOA concentrations by 50%/18%, while deteriorated meteorological conditions increased them by 30%/119%, resulting in a net decrease in the POA concentration and a net increase in the SOA concentration.

Observed changes in China's methane emissions linked to policy drivers.

China is set to actively reduce its methane emissions in the coming decade. A comprehensive evaluation of the current situation can provide a reference point for tracking the country's future progress. Here, using satellite and surface observations, we quantify China's methane emissions during 2010-2017.

QTL mapping and identification of candidate genes using a genome-wide association study for heat tolerance at anthesis in rice ( L.).

Heat tolerance (HT) of rice at anthesis is a key trait that ensures high and stable yields under heat stress. Finding the quantitative trait loci (QTLs) and gene loci controlling HT is crucial. We used relative spikelet fertility (RSF) as a measure of HT.

Vertically Resolved Aerosol Chemistry in the Low Boundary Layer of Beijing in Summer.

Air quality in Beijing has been improved significantly in recent years; however, our knowledge of the vertically resolved aerosol chemistry in summer remains poor. Here, we carried out comprehensive measurements of aerosol composition, gaseous species, and aerosol optical properties on a meteorological tower in Beijing in summer and compared with those measured in winter. Our results showed that aerosol liquid water (ALW) contributing approximately 50% of the total mass with higher values aloft played a crucial role in aerosol formation.

Deep decarbonization of the Indian economy: 2050 prospects for wind, solar, and green hydrogen.

The paper explores options for a 2050 carbon free energy future for India. Onshore wind and solar sources are projected as the dominant primary contributions to this objective. The analysis envisages an important role for so-called green hydrogen produced by electrolysis fueled by these carbon free energy sources.

Ammonium Chloride Associated Aerosol Liquid Water Enhances Haze in Delhi, India.

The interaction between water vapor and atmospheric aerosol leads to enhancement in aerosol water content, which facilitates haze development, but its concentrations, sources, and impacts remain largely unknown in polluted urban environments. Here, we show that the Indian capital, Delhi, which tops the list of polluted capital cities, also experiences the highest aerosol water yet reported worldwide. This high aerosol water promotes secondary formation of aerosols and worsens air pollution.

The importance of hydroxymethanesulfonate (HMS) in winter haze episodes in North China Plain.

Hydroxymethanesulfonate (HMS), a key marker species of aqueous-phase processing, plays a significant role in sulfur budget in atmosphere. Here we have a comprehensive characterization of HMS at urban and rural sites in North China Plain (NCP) by using the real-time measurements from a high-resolution aerosol mass spectrometer (AMS) and a single-particle AMS together with offline filter analysis. Our results showed much higher winter concentration of HMS at the rural site (average±1σ: 2.

Production of hydrogen from offshore wind in China and cost-competitive supply to Japan.

The Japanese government has announced a commitment to net-zero greenhouse gas emissions by 2050. It envisages an important role for hydrogen in the nation's future energy economy. This paper explores the possibility that a significant source for this hydrogen could be produced by electrolysis fueled by power generated from offshore wind in China.

Residential building materials: An important source of ambient formaldehyde in mainland China.

This study investigates the contribution of formaldehyde from residential building materials to ambient air in mainland China. Based on 265 indoor field tests in 9 provinces, we estimate that indoor residential sources are responsible for 6.66% of the total anthropogenic formaldehyde in China's ambient air (range for 31 provinces: 1.

An Unambiguous Synchronization Scheme for GNSS BOC Signals Based on Reconstructed Correlation Function.

Binary offset carrier (BOC) modulation is a new modulation method that has been gradually applied to the Global Satellite Navigation System (GNSS) in recent years. However, due to the multi-peaks in its auto-correlation function (ACF), it will incur a false lock and generate synchronization ambiguous potentially. In this paper, an unambiguous synchronization method based on a reconstructed correlation function is proposed to solve the ambiguity problem.

Ozone pollution in the North China Plain spreading into the late-winter haze season.

Surface ozone is a severe air pollution problem in the North China Plain, which is home to 300 million people. Ozone concentrations are highest in summer, driven by fast photochemical production of hydrogen oxide radicals (HO) that can overcome the radical titration caused by high emissions of nitrogen oxides (NO) from fuel combustion. Ozone has been very low during winter haze (particulate) pollution episodes.