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The contribution of excavated waste to waste management is multifaceted, including minimization, non-hazardous disposal, access to useable land resources, improved waste management techniques and public environmental awareness, consistent with recent circular economy initiatives. Pyrolysis can be converted into tar, pyrolysis gas and char with recyclable utilization, enriching the application of pyrolysis technology in the field of excavation waste. In this study, the pyrolysis system includes horizontal tube furnace, gas collection device and Micro GC. The excavated waste was pyrolyzed at a temperature of 500∼900 °C with a heating rate of 10 °C/min. Pyrolysis gases include H 2 , CO, CO 2 , CH 4 , C 2 H 4 , C 2 H 6 and C 3 H 8. Pyrolysis was divided into four stages, the main decomposition range is 230∼500 °C, with a weight loss rate of 68.49% and a co-pyrolysis behavior. As the temperature increases, the tar and char decreased and the gas production increased significantly, and the pyrolysis gas reached 47.02% at 900 °C. According to Pearson correlation coefficient analysis, the generation of H 2 and CO is positively correlated with temperature. Therefore, the target products can be influenced by changing the parameters, when considering the practical utilization of the excavated waste pyrolysis products. On this basis, the prediction models were built by polynomial fitting method. This model can reduce the experimental exploration cycle, reduce the cost, and accurately predict the pyrolysis gas, which has practical guidance for the application of pyrolysis industry, and provides a theoretical basis for the resource recycling and energy recovery of landfill. [Display omitted] • Thermogravimetric properties and kinetic analysis of excavated waste were studied. • The high temperature favors the production of H 2 /CO, and hinders the CO 2 /CH 4. • The correlation of pyrolysis gas generation was analyzed by Statistical method. • The gas prediction model was built using a polynomial fitting method. [ABSTRACT FROM AUTHOR]

• The ET value of various crops in different soils were determined by SWAP model. • Farmland target ET indicator was separated from the regional target ET. • Soil and water resources were optimally allocated under farmland target ET. • Multi-objective optimal allocation of soil and water resources model was established. • The results showed that the economic benefit and water use efficiency were improved. There is a mismatch between crop water demand, the spatial and temporal distribution of natural rainfall, surface water sources, and arable land resources in the North China Plain. This has been compensated for by massive groundwater exploitation, and as a result, ground water levels have continuously declined and groundwater landing funnels have formed in some areas. Consequently, there is an urgent need for the rational allocation of soil and water resources. In this study, regional soil types and the corresponding crops in Guangping County, Hebei Province, China, alongside the regional annual average total water consumption were used to determine reasonable allocations for crop planting structures, with an aim of maximizing the water utilization efficiency and economic benefits while also achieving a regional groundwater dynamic equilibrium. Daily meteorological data from 1973 to 2021, including precipitation, temperature, sunshine hours, wind speed, and humidity, as well as crop data, including irrigation systems and crop growth status, were collected. Water consumption models for eight soil types and seven typical crops forming 56 calculation partitions were established to obtain annual average water consumption values for the different crops. The maximum economic benefit and water-use efficiency were then used as the objective functions and total water consumption as the control condition for the non-dominated sorted genetic algorithm-Ⅱ (NSGA-II), to optimize the allocation of soil and water resources in the region; the adjusted quantities for the different crops cultivated under different soil types in the study area were obtained. The areas growing sweet potato and vegetable-fruits were found to increase by 0.5255 km2 and 4.4452 km2, respectively, when compared to the pre-optimization period, whereas the areas with winter wheat-summer maize, millet, peanut, cotton, and summer maize decreased by 1.3481 km2, 0.1812 km2, 0.7316 km2, 2.0896 km2, and 0.62 km2, respectively. The economic benefit increased from 810.37 to 853.64 million yuan, while the water-use efficiency increased from 1.5426 kg/m3 to 1.5859 kg/m3. The results provide a basis for soil and water resource management in the region and a technical reference for similar areas to improve agricultural water-use efficiency and economic benefits. [ABSTRACT FROM AUTHOR]

[Display omitted] • PCR-CF inhibits tumor growth in mice with lung cancer. • PCR-CF induces ROS-dependent cell apoptosis and cycle arrest to achieve the inhibitory effects against NSCLC. • The inhibitory effects of PCR-CF against NSCLC improve with the extension of storage periods. • Nobiletin and tangeretin in PCR-CF during storage collectively contributed to inhibitory effect against NSCLC. Pericarpium Citri Reticulatae 'Chachi' (PCR-C), rich in flavonoids, shows antioxidative, anti-inflammatory, and antitumor effects, which was traditionally considered to be "the longer periods, the better". The bioactivity of flavonoids depends on gastrointestinal absorption and hepatic metabolism. This work aims to investigate which metabolites of flavonoids are the differential factors that mainly contributed to the variance of inhibitory effect of PCR-C flavonoid extracts (PCR-CF) against non-small cell lung cancer (NSCLC) during storage. The inhibitory effect of PCR-CF against NSCLC was evaluated by subcutaneous xenograft tumor model and Caco-2/HepG2 coculture model. Non-targeted metabolomics was employed to analyze the metabolic difference of PCR-CF during storage. Results showed that PCR-CF during storage inhibited tumor growth in vivo. Meanwhile, PCR-CF during storage inhibited A549 cell proliferation and induced cell apoptosis and cell cycle arrest at G2/M phase via ROS-dependent generation involving in MAPK pathway in vitro. Furthermore, 15 flavonoids metabolites were identified as marker differential metabolites affecting the variance of inhibitory effect of PCR-CF during storage against NSCLC. This study indicated that the inhibitory effects of PCR-CF against NSCLC were improved with the extended storage periods due to the variance of differential metabolites. The results would provide scientific guidance for quality control of PCR-C during storage. [ABSTRACT FROM AUTHOR]

Graphical abstract A comprehensive and categorized review on performances of various phosphate adsorbents, especially those that emerged in last decade, is presented. Abstract Eutrophication, a worldwide problem, threatens the ecology of freshwater bodies and marine environments. However, the control of nutrients, especially phosphate in water bodies and contaminated sediments, poses major technical and economic challenges. Today, various attempts have been made to investigate a cost-effective way to have phosphate control. Among the various techniques applied to remove phosphate, the process of adsorption has drawn great attention due to its low cost, ease of operation, and simplicity of design. Another attractive feature of adsorption is the usage of nutrient-loaded adsorbents, which can be used as a phosphate fertilizer and a soil conditioner in agriculture. In this regard, many different types of chemicals with various structures have been synthesized and applied for the capture of phosphate from water. This review summaries contemporary development of adsorbents for phosphate removal, most specifically, the adsorption by metal-based materials, mesoporous materials, organic and metal-organic hybrid materials, carbon-supported materials, minerals, and modified wastes. The effects of operational parameters on phosphate adsorption and fitting of adsorption process, as well as regeneration of used adsorbents are also examined. Metal (hydr)oxides loaded adsorbents have been widely researched. Additional modifying of material characteristics such as improving porosity and surface area, the stability and potential risks of adsorbents in complex condition, and their efficient separation and regeneration should be taken into consideration in further studies. [ABSTRACT FROM AUTHOR]

In this study, some key geometric and thermal parameters derived from recent field and satellite observations in Beijing were collected and incorporated into WRF-UCM (Weather Research and Forecasting) model instead of previous default ones. A series of sensitivity model simulations were conducted to investigate the influences of these parameters on radiation balance, meteorological variables, turbulence kinetic energy (TKE), as well as planetary boundary layer height (PBLH) in regions around Beijing in summer 2014. Model validation demonstrated that the updated parameters represented urban surface characteristics more realistically and the simulations of meteorological variables were evidently improved to be closer to observations than the default parameters. The increase in building height tended to increase and slightly decrease surface air temperature at 2 m (T2) at night and around noon, respectively, and to reduce wind speed at 10 m (WS10) through a day. The increase in road width led to significant decreases in T2 and WS10 through the whole day, with the maximum changes in early morning and in evening, respectively. Both lower surface albedo and inclusion of anthropogenic heat (AH) resulted in increases in T2 and WS10 over the day, with stronger influence from AH. The vertical extension of the impact of urban surface parameters was mainly confined within 300 m at night and reached as high as 1600 m during daytime. The increase in building height tended to increase TKE and PBLH and the TKE increase was larger at night than during daytime due to enhancements of both mechanical and buoyant productions. The increase in road width generally reduced TKE and PBLH except for a few hours in the afternoon. The lower surface albedo and the presence of AH consistently resulted in increases of TKE and PBLH through both day and night. The increase in building height induced a slight divergence by day and a notable convergence at night, whereas the increase in road width led to a remarkable divergence through the entire day. Both AH and lower surface albedo induced a wind convergence over the day, which tended to strengthen nighttime mountain downslope wind and daytime southerly wind to the south of Beijing, but to weaken daytime upslope wind in mountain areas. [ABSTRACT FROM AUTHOR]

Abstract: [Cp2Ln(μ-OH)(THF)]2 react with 2 equiv of CyNCNCy (Cy = cyclohexyl) to form [Cp2Ln(μ-OC(NHCy)NCy)]2 (Ln = Er (1-Er), Y (1-Y)), while treatment of [Cp2Ln(μ-OH)]2(μ3-O)LnCp(THF) with CyNCNCy affords the addition/rearrangement products [Cp2Ln(μ3-O)(μ-OC(NHCy)NCy)LnCp]2 (Ln = Yb (3-Yb), Er (3-Er)). Compounds [(Cp2Ln)2(μ3-CO3)(THF)]2 (Ln = Yb (4-Yb), Er (4-Er)) can be obtained by treatment of [Cp2Ln(μ-OH)(THF)]2 with CO2 immediately followed by the reaction with the corresponding Cp3Ln. Complexes 1–4 were characterized by elemental analysis, spectroscopic properties and X-ray single crystal diffraction analysis. [Copyright &y& Elsevier]

The purpose of this study was to investigate the dynamic changes in serum (1-3)-β-D-glucan (BDG) caused by intravenous immunoglobulins (IVIG) infusion in adults. This study included patients who received IVIG infusion from October 2021 to October 2022 during hospitalization. We randomly examined two IVIG samples for every patient. Serum samples were collected at nine time points: before (Tpre), immediately (T1-0), 6h (T1-1) and 12h (T1-2) later on the first day; immediately (T2-0) and six hours later (T2-1) on the second day during IVIG infusion, and within three days after IVIG infusion (Ta1, Ta2, and Ta3, respectively). The Friedman test was used for statistical analysis. A total of 159 serum BDG from 19 patients were included in the analysis. The BDG content of IVIG ranged from 249 pg/ml to 4812 pg/ml. Patients had significantly elevated serum BDG on T1-0 (176 (113, 291) pg/ml, p = 0.002) and Ta1 (310 (199, 470) pg/ml, p < 0.001), compared with Tpre (41 (38, 65) pg/ml). The increments of serum BDG (ΔBDG) were associated with BDG concentration of IVIG (Spearman r = 0.59, p = 0.02). Individuals with abnormal renal function indexes showed higher serum ΔBDG values at Ta1 (403 (207, 484) pg/ml) than patients with normal renal function (172 (85, 316) pg/ml, p = 0.036). Patients who received IVIG had significantly higher serum BDG values. Elevated BDG levels correlate with BDG content of IVIG and abnormal renal function indexes. [ABSTRACT FROM AUTHOR]

• An electrode based on MOF-derived Al/C was developed for phosphate removal. • Al/C prepared by two-step calcination showed a stable and conductive structure. • The electrode affords a maximum adsorption capacity of 97.73 mg P/g for 1 V condition. • The electrode could be directly separated from the treated wastewater. • The desorption efficiency reached 89% in 20 min. Porous metal-organic frameworks (MOFs) have drawn increasing attention as promising phosphate adsorbents. Yet the potential agglomeration of MOFs particles and the difficult collection process largely thwarted their application. Meanwhile, adsorbents regeneration might destroy MOFs structures due to the use of strong alkaline solution. In this work, we reported a strategy for designing and fabricating an electrode to remove phosphate based on MIL-101 derived metal/carbon via a two-step carbonization step, which not only introduced C doping but also created a stable structure. With the assistance of electric field, the migration and capture of phosphate anions were greatly enhanced. Under 1 V condition, the material exhibited a high maximum removal capacity of 97.73 mg P/g. Adsorption kinetics and parameters for phosphate at different conditions were analyzed. Langmuir and Freundlich isotherms were employed to validate the adsorption data. More importantly, the regeneration of electrode was achieved in a more facile and efficient way than micro/ nanoparticles adsorbents by simple voltage control. Such an intriguing approach may provide a new platform to further expand the use of MOFs for adsorption process. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Spatial navigation consistently activates posterior brain regions. • Insula and claustrum involve in human spatial navigation. • Specific type of spatial information activates part of the navigational system. • Map-based navigation needs further processing than route-based navigation. Spatial navigation is a crucial ability involving the interplay of multiple cognitive processes and is related to input spatial information (such as landmarks and orientation cues) and output navigational strategies (such as route-based and map-based). It is still not clear where is the spatial navigation system and whether these tasks evoke different activation patterns in human brain. Thus, we analyzed the reported brain activations of 33 related functional neuroimaging studies by using activation likelihood estimation (ALE) meta-analyses. Statistical analysis revealed a navigational system including the hippocampus, parahippocampal place area (PPA), retrosplenial complex (RSC), occipital place area (OPA), and insula. More likely, landmarks activate the left secondary motor cortex (SMC), whereas orientation cues activate the right somatosensory associative cortex (SAC). Although no region showed stronger activation likelihood in route- than map-based navigation, the map-based navigation had stronger activation likelihood in the right SAC than route-based navigation. These findings revealed the brain representation of spatial navigational system and suggested that different parts of this system are involved with the specific navigational tasks. [ABSTRACT FROM AUTHOR]

Carotid atherosclerosis is an important cause of ischemic stroke. Lipids play a key role in the progression of atherosclerosis. To date, the spatial lipid profile of carotid atherosclerotic plaques related to histology has not been systematically investigated. Carotid atherosclerosis samples from 12 patients were obtained and classified into four classical pathological stages (preatheroma, atheroma, fibroatheroma and complicated lesion) by histological staining. Desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) was used to investigate the lipid profile of carotid atherosclerosis, and correlated it with histological information. Bioinformatics technology was used to process MSI data among different pathological stages of atherosclerosis lesions. A total of 55 lipids (26 throughout cross-section regions [TCSRs], 13 in lipid-rich regions [LRRs], and 16 in collagen-rich regions [CRRs]) were initially identified in carotid plaque from one patient. Subsequently, 32 of 55 lipids (12 in TCSRs, eight in LRRs, and 12 in CRRs) were further screened in 11 patients. Pathway enrichment analysis showed that multiple metabolic pathways, such as fat digestion and absorption, cholesterol metabolism, lipid and atherosclerosis, were enriched in TCSRs; sphingolipid signaling pathway, necroptosis pathway were enriched in LRRs; and glycerophospholipid metabolism, ether lipid metabolism pathway were mainly enriched in CRRs. This study comprehensively showed the spatial lipid metabolism footprint in human carotid atherosclerotic plaques. The lipid profiles and related metabolism pathways in three regions of plaque with disease progression were different markedly, suggesting that the different metabolic mechanisms in these regions of carotid plaque may be critical in atherosclerosis progression. [Display omitted] • Specific lipids located in lipid-rich regions and collagen-rich regions were identified. • The spatial dynamic lipid metabolism footprint of atherosclerosis was delineated. • Different metabolic pathways between lipid-rich regions and collagen-rich regions with atherosclerosis progression were found. [ABSTRACT FROM AUTHOR]

A simple, cheap, efficient, and metal-free method for one-step synthesis of a library of 1,3-diheteroatom five-membered heterocycles with exocyclic C N and C C double bonds was presented. The convenient reactions proceed via the direct three-component halocyclization of propargylamines, heterocumulenes and I 2 (NBS). [ABSTRACT FROM AUTHOR]

Abstract: The FeCl3-promoted annulation reaction of aryl acetaldehydes with alkynes has been established, which provides a new and versatile straightforward procedure for the regioselective synthesis of mono-, di-, and polysubstituted naphthalenes under mild conditions. Interestingly, the present catalytic system not only differentiates between internal and terminal alkynes but also shows unprecedented complete Me3SiOH elimination selectivity for silyl alkyne substrates. Furthermore, the synthesis of a series of substituted phenanthrenes via reactions of nathphyl acetaldehydes with internal alkynes is also achieved for the first time in good yields with excellent regioselectivity. [Copyright &y& Elsevier]

Abstract: The copper-catalyzed chalcogenoamination of 2-alkynylanilines with dichalcogenides has been achieved under mild reaction conditions using the weak base Cs2CO3 in combination with air oxidant, providing a convenient and efficient method for synthesis of 3-sulfenylindoles and 3-selenylindoles, including complex products bearing two attached 3-sulfenylindole rings. [Copyright &y& Elsevier]

• Constructed a groundwater numerical model by Visual MODFLOW and studized the feasibility of mine water recharge to aquifers. • Analyzed the impact of mine water recharge on the water level and inflow of aquifers. • To ensure the safe mining in the future, the dynamic water inflow under different mining levels was predicted. Water inflow poses a critical safety concern in coal mining. The pressing challenge in current mine water inflow research is the need to enhance the prediction of dynamic changes in mine water inflow across different mining stages. In this study, the hydrogeological conditions and aquifer structural characteristics of the Wutongzhuang Coal Mine in Hebei Province, China were analyzed, and the results were combined with pumping test and drilling data. A numerical model of groundwater flow in the study area was established using Visual MODFLOW and the model was calibrated and verified by comparing its results with the measured values to ensure that it realistically reflected the state of groundwater movement in the study area. The results of numerical simulation indicated that: (1) The water level of the Ordovician aquifer varies significantly by season. A large exposed area of Ordovician limestone in the western mountainous region receives a large amount of rainfall infiltration recharge in the summer rainy period that raises the water level of the Ordovician aquifer in the study area. (2) The groundwater system in the study area is in an equilibrium state, with the water inflow approximately equal to the outflow. (3) The recharge of mine drainage water has a slight positive effect on the Ordovician water level and the floor water inflow, with the impact on the water level of the aquifer decreasing as the distance from the recharge well and the import of Ordovician limestone water increase. In cases in which there is mine water recharge, the water level of the Ordovician aquifer is approximately 0.33 to 1.37 m higher than in cases without recharge, resulting in an increase in water inflow of approximately 10.6 m3/d. (4) In cases in which there is recharge of all drainage water, the maximum water inflow into the fifth mining area is 3,491.3 m3/d, which is 12.5 m3/d higher than in the case without recharge. These results provide important technical references for the formulation of mining schemes and water prevention measures in mining areas. [ABSTRACT FROM AUTHOR]

Abstract Objective The study aimed to ascertain the correlation between AKR1B1 polymorphism rs759853 and the risk of diabetic retinopathy (DR) through a meta-analysis. Methods Crude odds ratios (ORs) and the corresponding 95% confidence interval (95% CIs) were calculated to assess the association of AKR1B1 rs759853 polymorphism with DR risk. Stratification analyses were further conducted based on ethnicity, diabetes mellitus (DM) type, Hardy-Weinberg equilibrium (HWE) status, and genotyping method. Heterogeneity was detected by Q test. Sensitivity analysis was implemented to check the robustness of final results. Additionally, Begg's funnel plot and Egger's test were used to evaluate underlying publication bias. Results Our meta-analysis ultimately incorporated 21 eligible publications with 22 independent case-control studies. The overall results demonstrated that AKR1B1 rs759853 polymorphism had no association with DR risk under all genetic models. However, after subgroup analysis by DM type, the rs759853 polymorphism was a protective factor against the DR onset in patients with type 1 DM (TT vs. CC: OR = 0.33, 95% CI = 0.17–0.67; TT + CT vs. CC: OR = 0.49, 95% CI = 0.36–0.68; TT vs. CC + CT: OR = 0.48, 95% CI = 0.28–0.83; allele T vs. allele C: OR = 0.56, 95% CI = 0.44–0.72; CT vs. CC: OR = 0.52, 95% CI = 0.37–0.74). Furthermore, subgroup analysis by genotyping method suggested that rs759853 genotyped using MassARRAY assay was significantly correlated with decreased risk of DR under dominate model (TT + CT vs. CC: OR = 0.71, 95%CI = 0.52–0.96). Conclusion AKR1B1 polymorphism rs759853 may inhibit the occurrence of DR in patients with type 1 DM. Highlights • A meta-analysis. • AKR1B1 rs759853 reduced DR risk in T1DM. • Rs759853 genotyped by MassARRAY influenced DR risk. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the changes in serum (1-3)-β-D-glucan (BDG) in adults due to intravenous immunoglobulins (IVIG) infusion and the factors that affect these changes. Patients who had BDG tests both before and after IVIG infusion during hospitalization were retrospectively included, and trends in BDG values were analyzed before and after IVIG infusion. Factors associated with false-positive BDG were then explored using univariate analysis. A total of 347 serum BDG tests from 131 patients were included in the analysis, and 71.8% (94/131) patients had false positive serum BDG after IVIG infusion. All BDG values on day 7 were negative. Univariate analysis showed that patients with false positive BDG tests had higher daily IVIG doses (P = 0.043) and higher levels of serum IgG increments (P = 0.001). The median peak blood BDG on day 1 after completion of IVIG infusion was 199.6 (154.5–277.7, inter-quartile ranges (IQR)) pg/mL, and both the peak BDG and incremental BDG values (ΔBDG, BDG at the first day after IVIG infusion minus BDG before infusion) were slightly and positively correlated with ΔIgG (BDG vs. ΔIgG, P = 0.0016; ΔBDG vs. ΔIgG, P = 0.0003). Most adults showed false positive BDG tests after IVIG infusion and negative BDG tests within 1 week. Daily IVIG dosage may contribute to the evaluation of ΔBDG. [ABSTRACT FROM AUTHOR]

[Display omitted] To identify pore domain ligands on Kv7.2 potassium ion channels, we compared wild-type (WT) and W236L mutant Kv7.2 channels in a series of assays with previously validated and novel agonist chemotypes. Positive controls were retigabine, flupirtine, and RL-81; i.e. Kv7.2 channel activators that significantly shift voltage-dependent activation to more negative potentials (ΔV 50) at 5 µM. We identified 6 new compounds that exhibited differential enhancing activity between WT and W236L mutant channels. Whole cell patch-clamp electrophysiology studies were conducted to identify Kv7.2. Kv7.2/3, Kv7.4, and Kv7.5 selectivity. Our results validate the SyncroPatch platform and establish new structure activity relationships (SAR). Specifically, in addition to selective Kv7.2, Kv7.2/3, Kv7.4. and Kv7.5 agonists, we identified a novel chemotype, ZK-21, a 4-aminotetrahydroquinoline that is distinct from any of the previously described Kv7 channel modifiers. Using flexible receptor docking, ZK-21 was predicted to be stabilized by W236 and bind perpendicular to retigabine, burying the benzyl carbamate group into a tunnel reaching the core of the pore domain. [ABSTRACT FROM AUTHOR]

Abstract: An efficient, convenient, and one-pot procedure for the synthesis of a series of new dihydro- and tetrahydronaphthalenes as well as tetrahydroisoquinolines has been established through Lewis acid-catalyzed intramolecular Friedel–Crafts reaction of aryl-substituted propargylic alcohols. [Copyright &y& Elsevier]

The model simulated surface mean SOA concentrations produced from (a) AVOCs, (b) SVOCs, (c) IVOCs, (d) aromatics, (e) alkenes and (f) alkanes (unit: μg m−3) during February 20-March 13, 2014 in the BTH region of eastern China. • Evolution of organic aerosols in winter in Beijing is investigated. • SOA simulation is apparently improved by considering S/IVOCs. • The SOA/OA ratio gradually increases from clean days to hazy days. • The SOA increase in haze days results from competing processes. A regional air quality model system (RAQMS) with a volatility basis set approach for secondary organic aerosol (SOA) formation and an emission inventory of semi-volatile (SVOC) and intermediate volatile organic compounds (IVOC) are applied to investigate the distribution and evolution of organic aerosols over the Beijing-Tianjin-Hebei (BTH) region in winter 2014, with focus on Beijing. Model validation demonstrates the model is capable of reproducing meteorological variables and major aerosol components, and the model significantly improves SOA and organic aerosol (OA) simulations by taking S/IVOCs (SVOC + IVOC) and relevant aging processes into account. SVOC and IVOC emissions in the BTH region are estimated to be 0.47 Tg and in a range of 0.09–0.36 Tg, respectively, which are about 18% and 4–14% of the emission amounts of volatile organic compounds (VOCs). The distribution of mean organic aerosols is characterized by a high concentration belt oriented southwest-northeast from southern Hebei to Beijing, with the maximum concentration up to 50 μg m−3 in Beijing and Shijiazhuang. The simulated SOA concentration is comparable in magnitude to primary organic aerosol (POA) concentration, and the SOA/OA ratio is around 50% in most areas of the BTH region. In terms of domain average, the percentage contributions to SOA mass concentration from anthropogenic volatile organic compounds (AVOCs), SVOCs, IVOCs and biogenic VOCs are estimated to be 46.1%, 40.1%, 9.4% and 4.4%, respectively, in the BTH region during the study period, which indicates an important role of S/IVOCs in SOA formation. From clean to haze periods, both POA and SOA concentrations apparently increase, with an increasing (decreasing) trend of the SOA/OA (POA/OA) ratio. SOA dominates over POA in fine organic aerosols during the haze periods. The increase of POA in hazy days is mainly due to the weakened vertical diffusion and accumulation near the surface, whereas the increase of SOA is likely attributed to both the reduced diffusivity and a series of competing chemical processes, in which the decreased photolysis rate by aerosol attenuation tends to decrease SOA concentration by about 6% during the most severe haze day, whereas the lower surface air temperature and higher POA and S/IVOC concentrations in haze days both enhance gas to particle partition, and consequently lead to higher SOA concentration. [ABSTRACT FROM AUTHOR]