Showing papers by "Hong Wang published in 2023"
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Abstract: Abstract. Oxygenated organic molecules (OOMs) are dominated by the N-containing
species in polluted urban environments. As N-containing OOMs, especially
those with more than one nitrogen atom, prevail in the high m/z (mass-to-charge) range
(m/z> 350 Th), unambiguous identification of N-containing OOMs is
highly desirable for understanding of their formation processes, precursors
and influencing factors. To achieve this, we applied an
ultra-high-resolution chemical-ionization Orbitrap (CI-Orbitrap) in a field
campaign and found that OOMs contain one (1N-OOMs), two (2N-OOMs) and three
(3N-OOMs) nitrogen atoms comprised 50 %, 26 % and 4 %, respectively, of
total OOMs. More interestingly, the fraction of 2N-OOMs increased with the
increase in carbon number (nC) and was dominated by the ones derived from
aliphatic precursors (2N-OOMAli, 64.2 %), indicating the importance
of multistep oxidation. Plausible precursors of 2N-OOMs were aliphatics
(2N-OOMAli, 64.2 %), aromatics (2N-OOMAro, 16 %) and
monoterpenes (2N-OOMMT, 15.4 %). The absolute concentrations of
2N-OOMs were greatly affected by the pollution level for most cases. The
2N-OOMAli was the most abundant 2N-OOM, and its fraction even increased
on the polluted day with an enhanced proportion of the ones with nC >10. While 2N-OOMAli and 2N-OOMAro were dominated by daytime
photochemical production, nighttime NO3-initiated oxidation played a
comparable role to the daytime photochemistry in the formation of
2N-OOMMT. The 2N-OOMAro species were of the highest oxygenation level, followed by
2N-OOMMT and 2N-OOMAli, which were affected by photochemistry and
NOx concentrations. These results highlight the significant formation
of 2N-OOMs and the influencing factors on their formation in polluted urban
environments, where various volatile organic compound (VOC) precursors and atmospheric oxidants are present.
1 citations
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TL;DR: In this article , a new porous organic polymer (CTF-CAR), which takes carbazole as the electron-rich center unit and thiophenes as the auxiliary group, has been synthesized through catalyst-free Schiff-base polymerization.
Abstract: A new porous organic polymer (CTF-CAR), which takes carbazole as the electron-rich center unit and thiophenes as the auxiliary group, has been synthesized through catalyst-free Schiff-base polymerization. At the same time, the structure, thermal stability, morphology, and other basic properties of the polymer were analyzed by IR, NMR, TGA, and SEM. Then, CTF-CAR was applied to iodine capture and rhodamine B adsorption. Due to its strong electron donor ability and abundant heteroatom binding sites, which have a positive effect on the interaction between the polymer network and adsorbates, CTF-CAR exhibits high uptake capacities for iodine vapor and rhodamine B as 2.86 g g-1 and 199.7 mg g-1, respectively. The recyclability test also confirmed that it has good reusability. We found that this low-cost and catalyst-free synthetic porous organic polymer has great potential for the treatment of polluted water and iodine capture.
1 citations
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TL;DR: In this paper , the authors applied a random forest (RF) algorithm to quantify drivers of PM2.5 trends in six cities of the Tibetan Plateau from 2015 to 2022.
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TL;DR: In this paper , the authors report observation results of Cl2, ClNO2, and N2O5 from measurements using high-resolution time-of-flight chemical ionization mass spectrometry (HR-ToF-CIMS) in Shanghai and Changzhou in the highly industrialized and populated Yangtze River Delta (YRD) of East China.
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TL;DR: In this paper , large-scale mobile observations of gas-phase dimethylamine (DMA) concentrations within cities and across two pan-region transects of north-to-south (∼700 km).
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TL;DR: In this paper , the effect of DOX removal by potassium ferrate (Fe(VI)) and montmorillonite (MfM) dosage, reaction time, initial pH value, and dosage of Fe(VI) was investigated.
Abstract: Doxycycline (DOX), a typical antibiotic, is harmful to aquatic ecosystems and human health. This study presents DOX removal by potassium ferrate (Fe(VI)) and montmorillonite and investigates the effect of Fe(VI) dosage, reaction time, initial pH value, montmorillonite dosage, adsorption pH, time and temperature on DOX removal. The results show that DOX removal increases when increasing the Fe(VI) dosage, with the optimal condition for DOX removal (~97%) by Fe(VI) observed under a molar ratio ([Fe(VI)]:[DOX]) of 30:1 at pH 7. The reaction of DOX with Fe(VI) obeyed second-order kinetics with a rate constant of 10.7 ± 0.45 M−1 s−1 at pH 7. The limited promotion (~4%) of DOX adsorption by montmorillonite was observed when the temperature increased and the pH decreased. Moreover, the synergetic effect of Fe(VI) and montmorillonite on DOX removal was obtained when comparing the various types of dosing sequences (Fe(VI) oxidation first and then adsorption; adsorption first and then Fe(VI) oxidation; simultaneous oxidation and adsorption). The best synergistic effect of DOX removal (97%) was observed under the simultaneous addition of Fe(VI) and montmorillonite, maintaining the Fe(VI) dosage (from 30:1 to 5:1). Five intermediates were detected during DOX degradation, and a plausible DOX degradation pathway was proposed.
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TL;DR: In this article , the authors quantified the gas vs. particle-phase fractions of a large number of semivolatile organic compounds (SVOCs) in real time in an urban area of East China with the use of a CHEMICAL Analysis of aeRosols ONLINE (CHARON) inlet coupled to a high-resolution proton-transfer-reaction time-of-flight mass spectrometer.
Abstract: Abstract. Understanding the gas–particle partitioning of semivolatile
organic compounds (SVOCs) is of crucial importance in the accurate
representation of the global budget of atmospheric organic aerosols. In this
study, we quantified the gas- vs. particle-phase fractions of a large number
of SVOCs in real time in an urban area of East China with the use of a
CHemical Analysis of aeRosols ONline (CHARON) inlet coupled to a high-resolution proton-transfer-reaction time-of-flight mass spectrometer
(PTR-ToF-MS). We demonstrated the use of the CHARON inlet for highly
efficient collection of particulate SVOCs while maintaining the intact
molecular structures of these compounds. The collected month-long dataset
with hourly resolution allows us to examine the gas–particle partitioning of
a variety of SVOCs under ambient conditions. By comparing the measurements
with model predictions using instantaneous equilibrium partitioning
theory, we found that the dissociation of large parent molecules during the
PTR ionization process likely introduces large uncertainties to the measured
gas- vs. particle-phase fractions of less oxidized SVOCs, and therefore,
caution should be taken when linking the molecular composition to the
particle volatility when interpreting the PTR-ToF-MS data. Our analysis
suggests that understanding the fragmentation mechanism of SVOCs and
accounting for the neutral losses of small moieties during the molecular
feature extraction from the raw PTR mass spectra could reduce, to a large
extent, the uncertainties associated with the gas–particle partitioning
measurement of SVOCs in the ambient atmosphere.
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TL;DR: In this paper , a cost-effective biochar addition was proposed to improve the membrane fouling and nitrogen removal in municipal wastewater, which significantly altered the mixed liquor suspension with soluble microbial product (SMP) concentration reduction of approximately 14%.
Abstract: Membrane bioreactors (MBRs) are frequently used to treat municipal wastewater, but membrane fouling is still the main weakness of this technology. Additionally, the low carbon-nitrogen (C/N) ratio influent has been shown to not only increase the membrane fouling, but also introduce challenges to meet the effluent discharge standard for nitrogen removal. Herein, the authors addressed the challenges by adding cost-effective biochar. The results suggested that the biochar addition can enable membrane fouling alleviation and nitrogen removal improvement. The reduced membrane fouling can be ascribed to the biochar adsorption capacity, which facilitates to form bigger flocs with carbon skeleton in biochar as a core. As a result, the biochar addition significantly altered the mixed liquor suspension with soluble microbial product (SMP) concentration reduction of approximately 14%, lower SMP protein/polysaccharide ratio from 0.28 ± 0.02 to 0.22 ± 0.03, smaller SMP molecular weight and bigger sludge particle size from 67.68 ± 6.9 μm to 113.47 ± 4.8 μm. The nitrogen removal is also dramatically improved after biochar addition, which can be due to the initial carbon source release from biochar, and formation of aerobic–anaerobic microstructures. Microbial diversity analysis results suggested more accumulation of denitrification microbes including norank_f__JG30-KF-CM45 and Plasticicumulans. Less relative abundance of Aeromonas after biochar addition suggested less extracellular polymer substance (EPS) secretion and lower membrane fouling rate.
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TL;DR: In this paper , an autologous cellular immunotherapy (CIT) composed of cytokine-induced killer (CIK, natural killer (NK), and T cells was combined with platinum-based chemotherapy for non-small cell lung cancer.
Abstract: Platinum-based chemotherapy is the primary treatment option for advanced non-small cell lung cancer (NSCLC) patients without a driver gene mutation, but its efficacy is still modest. Through a potential synergistic effect, autologous cellular immunotherapy (CIT) composed of cytokine-induced killer (CIK, natural killer (NK), and T cells) might enhance it. NK cells exhibited in vitro cytotoxicity toward lung cancer cells (A549 cells) following platinum therapy. Using flow cytometry, the expression of MICA, MICB, DR4, DR5, CD112, and CD155 on lung cancer cells was assessed. In this retrospective cohort study, there were included 102 previously untreated stage IIIB/IV NSCLC patients ineligible for tyrosine kinase inhibitor (TKI) target therapy who received either chemotherapy alone (n = 75) or combination therapy (n = 27). The cytotoxicity of NK cells for A549 cells was increased obviously and a time-dependent enhancement of this effect was also observed. After platinum therapy, the levels of MICA, MICB, DR4, DR5, CD112, and CD155 on the surface of A549 cells were increased. In the combination group, the median PFS was 8.3 months, compared to 5.5 months in the control group (p = 0.042); the median overall survival was 18.00 months, compared to 13.67 months in the combined group (p = 0.003). The combination group had no obvious immune-related adverse effects. The combination of NK cells with platinum showed synergistic anticancer effects. Combining the two strategies increased survival with minor adverse effects. Incorporating CIT into conventional chemotherapy regimens may improve NSCLC treatment. However, additional evidence will require multicenter randomized controlled trials.
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TL;DR: In this paper , a near-complete characterization of reactive organic gases (ROGs) emissions from residential combustion was developed by the combination of proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) with a gas chromatography system equipped with a mass analyzer and a flame ionization detector (GC-MS/FID).
Abstract: Abstract. Reactive organic gases (ROGs), as important precursors of
secondary pollutants, are not well resolved as their chemical complexity
has challenged their quantification in many studies. Here, a near-complete
speciation of ROG emissions from residential combustion was developed by the
combination of proton transfer reaction time-of-flight mass spectrometry
(PTR-ToF-MS) with a gas chromatography system equipped with a mass spectrometer and a
flame ionization detector (GC-MS/FID), including 1049 species in all. Among
them, 125 identified species, ∼ 90 % of the total ROG
masses, were applied to evaluate their emission characteristics through
real combustion samplings in rural households of China. The study revealed
that with 55 species, mainly oxygenated species, higher hydrocarbons with
≥8 carbon atoms, and nitrogen-containing species, previously un- and
under-characterized, ROG emissions from residential coal and biomass
combustion were underestimated by 44.3 % ± 11.8 % and 22.7 % ± 3.9 %, respectively, which further amplified the underestimation
of secondary organic aerosol formation potential (SOAP) as high as 70.3 % ± 1.6 % and 89.2 % ± 1.0 %, respectively. The hydroxyl
radical reactivity (OHR) of ROG emissions was also undervalued
significantly. The study provided a feasible method for the near-complete
speciation of ROGs in the atmosphere and highlighted the importance of acquiring
completely speciated measurement of ROGs from residential emissions, as well
as other processes.
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22 May 2023
TL;DR: In this article , the authors conducted concurrent VOC measurements in the Pearl River Delta (PRD) region during the summer of 2018 and found large discrepancies in the spatiotemporal variations of VOCs between observations and model simulations when using the priori VOC emission inventory (Multi-resolution Emission Inventory for China).
Abstract: Volatile organic compounds (VOCs) have crucial influences on atmospheric chemistry. Accurate quantification of the VOC emissions is critical for air pollution research, especially when applying to air quality models. However, current bottom‐up emission inventories have biases, making observational constraints of VOC emissions necessary. We conducted concurrent VOC measurements in the Pearl River Delta (PRD) region during the summer of 2018 and found large discrepancies in the spatiotemporal variations of VOCs between observations and model simulations when using the priori VOC emission inventory (Multi‐resolution Emission Inventory for China). The normalized biases of total VOC concentrations ranged from −55% to 85% across the PRD cities in the study period. To improve the simulations, we constrained the anthropogenic VOC emissions based on their measured concentrations. The observation‐constrained VOC emissions showed clear diurnal variations and resolved the spatially‐concentrated priori emissions by reducing the high emissions by 15%–36% in the central PRD cities while elevating the sparse emissions in other cities. After employing the observation‐constrained VOC emissions, the model better reproduced the spatiotemporal variations of VOCs in the PRD region, alleviating the biases to −13%–13%. Furthermore, simulations of peak ozone (O3) concentrations were amended to reduce the mean normalized bias by 5%–12% on high O3 days. Our work has effectively combined VOC field measurements with air quality modeling to achieve better simulations of VOCs and O3. Besides, the observational‐constrained emissions are flexible for studying short‐term emission changes and their subsequent impacts on air quality.
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TL;DR: In this article , the authors used an acquisition system and developed an artificial neural network (ANN) model to automatically obtain the corresponding relationship between assisting sliding distance and speed in the aerials event of freestyle skiing.
Abstract: Abstract Automatically obtaining the launch speed are powerful guarantees for athletes in the aerials event of freestyle skiing to achieve good results. In most of the published studies describing athletes getting high scores, the assisting sliding distance depends entirely on the coach and even the athlete’s own experience, which may not be optimal. The main goal of the present paper is to use an acquisition system and develop an artificial neural network (ANN) model to automatically obtain the corresponding relationship between assisting sliding distance and speed. The influence of snow friction coefficient, wind speed, wind direction, slope, height and weight can be simulated in the Unity3D engine. The influence of temperature, humidity and tilt angle needs to be measured in real world by professional testers which is strenuous. The neural network is first trained by sufficient simulation data to obtain the encoded feature. Then, the information learned in simulation environment is transferred to another network. The second network uses the data taken from twenty professional testers. Compared with the model without transfer learning, the performance of proposed method has significant improvement. The mean squared error for the testing set is 0.692. It is observed that the speed predicted by the designed deep transfer learning (DTL) model is in good agreement with the experimental measurement results. The results indicate that the proposed transfer learning method is an efficient model to be used as a tool for predicting the assisting sliding distance and launch speed for athletes in the aerials event of freestyle skiing.
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TL;DR: In this paper , a superimposed code with threshold value d, which can recover the original code through the Boolean sum of up to d codes, is constructed by studying the problem of group testing.
Abstract: Considering emerging massive machine-type communication with very few devices simultaneously transmitting short messages, random multiple access has currently become a research hot spot since the traditional multiple access protocol struggles to work properly. Inspired by the superimposed code, a channel assignment scheme based on non-adaptive group testing theory is proposed to allow multiple users to share a single channel at the same time. A superimposed code with threshold value d, which can recover the original code through the Boolean sum of up to d codes, is constructed by studying the problem of group testing. When the number of active users with a message to be transmitted is no more than the threshold value, active users encode their messages by the superimposed code and multiple active users transmit their messages together by sharing a single channel. The receiver can decode the mixed messages by the disjunction of the superimposed code. We focus on the design of the superimposed code by group testing theory, formulate this problem as the construction of a transversal design, and use the Latin square to form a useful transversal design. Theoretical proof shows that our design works well under limited circumstances where the number of active users does not exceed the threshold value. Additionally, our design can recover the original codes by the mixture of codes, which are more easily than the algorithms based on compressive sensing. Simulation analysis presents that our design performs better than the traditional competitive access protocols in terms of successful probability, throughput, and packet loss rate.