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Grounded in the communication theory of resilience (CTR; Buzzanell, 2010, 2019), this manuscript reports on three studies that (a) develop a Chinese version of the CTR-based Communication Resilience Processes Scale (CRPS), (b) expand some CRPS subscales to more fully capture the meaning of resilience processes in Chinese contexts, (c) test the effects of resilience processes on measures of well-being (mental health, posttraumatic growth, satisfaction with life, and adjustment to college), and (d) examine Chinese cultural beliefs and values as predictors of resilience processes (consistent with CTR's concept of anticipatory resilience). Data offer initial support for the reliability and validity of the CRPS-Chinese (CRPS-CN). Findings illustrate the utility of adopting process views of resilience in Chinese contexts and highlight cultural implications of CTR's propositions and empirical studies of resilience. [ABSTRACT FROM AUTHOR]

High-flux solar simulator (HFSS) represents a vital category of controllable platforms designed to provide artificial solar radiation for reproducible studies on concentrated solar energy utilization. To simulate the performance of outdoor solar concentrators, two key metrics, namely, the range and uniformity of the deliverable energy flux, are critical for assessing the potential of HFSS for diverse solar applications. In this study, a 70-kW e HFSS is constructed to meet these requirements. The HFSS consists of seven high-performance and high-precision focusing radiation modules. In addition, by improving installation precision using the building-block method, a peak energy flux of 27.3 MW·m−2 is achieved. Moreover, an average energy flux of 9.4 MW·m−2 is obtained within a heat collection diameter of 50 mm, marking the highest reported value for HFSS with the same collection diameter to date. At the focal plane of the HFSS, the total deliverable energy flux is up to 26.7 kW, corresponding to a power-to-light efficiency of 40.11% (based on the 66% power-to-light efficiency of a xenon lamp). Notably, the energy-flux uniformity of heat collection area at the focal plane reaches 29.8%, which significantly surpasses the levels reported for conventional HFSS (approximately 10%). This improvement broadens the applicability of the HFSS and effectively mitigates hot spots and thermal stresses in the solar thermal collection process. Furthermore, a record-breaking maximum heat collection temperature of 3534 °C and a peak heating rate of 2097 °C·s−1 are also achieved. The application potential of the HFSS in solar thermochemical fuel production, melting of refractory materials, and thermal protection under high heat flux is also discussed. • A 70-kW e high-flux solar simulator with a peak energy flux of 27.3 MW·m−2 is developed. • A record-high mean energy flux of 9.4 MW·m−2 within a 50-mm aperture diameter. • A power-to-light efficiency of 40.11% within a 100-mm aperture diameter. • A record-high heat collection temperature of 3534 °C with a peak heating rate of 2097 °C·s−1. • Demonstration of applications for material processing and thermal protection. [ABSTRACT FROM AUTHOR]

• A rapid assessment model for screening nonstoichiometric oxides in two-step solar thermochemical cycling is developed. • Taking material thermodynamic properties as inputs, the solar-to-fuel efficiency is optimized with respect to cycling control parameters. • Material thermodynamic properties are found to have an enormous impact on optimal cycling conditions. • The solar-to-fuel efficiency of ceria can reach 12.9% at the reduction temperature of 1500 °C, which is the highest among the candidate oxides. • Ceria outperforms selected perovskite oxides in terms of efficiency for reduction temperature as low as 1350 °C. Two-step solar thermochemical cycling (STC) based on nonstoichiometric oxides is an ideal means of solar fuel (e.g. , H 2 , CO) production. Screening of nonstoichiometric oxides with excellent thermodynamic performance is key to achieving high solar-to-fuel efficiency. However, application-driven materials assessment intended for reactor-level solar fuel production performance requires mimicking realistic operating conditions of on-sun tests in a laboratory setting, which makes oxides assessment and screening an onerous task to accomplish experimentally. In this work, a rapid assessment and screening model of nonstoichiometric oxides for two-step solar thermochemical cycling assuming fixed-bed flow pattern and quasi-equilibration of the solid with the flowing gas phase is developed, with solar-to-fuel efficiency being the target function of optimization. The model accounts for the thermodynamic parameters of oxide materials and typical operating conditions of experimental thermochemical cycling. This study employed the model to explore and compare two groups of typical nonstoichiometric oxides (CeO 2 - and (LaSr)MnO 3 -based) for their maximum efficiency under their uniquely optimized cycling conditions. The results show that CeO 2 can reach a maximum efficiency of 12.9% at reduction temperature of 1500 °C, which is superior to other candidate materials, including 20 mol% Zr-doped CeO 2 (10.1%), La 0.6 Sr 0.4 MnO 3 (2.5%) and La 0.8 Sr 0.2 MnO 3 (3.3%). Even when the reduction temperature is lowered to 1350 °C, ceria yields the highest efficiency amongst the candidate STC materials considered. The optimal cycling strategy depends on the inherent thermodynamic properties of the oxides. This approach serves as a framework for assessing the maximum efficiency and optimal conditions of candidate thermochemical materials within a range of constraints rather than comparing materials under arbitrary cycling conditions, which may inherently favor one material over another. For oxidation temperatures below 800–1000 °C, the model could be further improved by considering reaction kinetics. [ABSTRACT FROM AUTHOR]

Multivalent ligands that exhibit high binding affinity to influenza hemagglutinin (HA) trimer can block the interaction of HA with its sialic acid receptor. In this study, a series of multivalent pentacyclic triterpene-functionalized per- O -methylated cyclodextrin (CD) derivatives were designed and synthesized using 1, 3-dipolar cycloaddition click reaction. A cell-based assay showed that three compounds ( 25 , 28 and 31 ) exhibited strong inhibitory activity against influenza A/WSN/33 (H1N1) virus. Compound 28 showed the most potent anti-influenza activity with IC 50 of 4.7 μ M. The time-of-addition assay indicated that compound 28 inhibited the entry of influenza virus into host cell. Further hemagglutination inhibition (HI) and surface plasmon resonance (SPR) assays indicated that compound 28 tightly bound to influenza HA protein with a dissociation constant ( K D ) of 4.0 μ M. Our results demonstrated a strategy of using per- O -methylated β -CD as a scaffold for designing multivalent compounds to disrupt influenza HA protein-host receptor protein interaction and thus block influenza virus entry into host cells. [ABSTRACT FROM AUTHOR]

A newly synthesized hexavalent oleanolic acid/per- O -methylated α -cyclodextrin conjugate shows significant differences in NMR spectra with previously synthesized analogs. Characterization of the product by 1 H NMR, 13 C NMR, COSY, HSQC, HMBC, TOCSY, NOE, and ROESY experiments were performed. Detailed investigations revealed that the compound has two conformations in solution and the ratio of them was 1:1. Further variable-temperature NMR study revealed that the two conformations were stable at temperature range of 273–323 K in CDCl 3 solution. [ABSTRACT FROM AUTHOR]

Recently, cuproptosis has been demonstrated to be a new non-apototic cell death mode that is characterized by copper dependence and the regulation of mitochondrial respiration. Cuproptosis is distinct from known cell death modes such as apoptosis, necrosis, pyroptosis, or ferroptosis. Excessive copper induces cuproptosis by promoting protein toxic stress reactions via copper-dependent anomalous oligomerization of lipoylation proteins in the tricarboxylic acid (TCA) cycle and reducing iron-sulfur cluster protein levels. Ferredoxin1 (FDX1) promotes dihydrolipoyl transacetylase (DLAT) lipoacylation and abates iron-sulfur cluster proteins by reducing Cu2+ to Cu+, inducing cell death. Copper homeostasis depends on the copper transporter, and disturbances to this homeostasis cause cuproptosis. Recent evidence has shown that cuproptosis plays a significant role in the occurrence and development of many cardiovascular diseases, such as myocardial ischemia/reperfusion (I/R) injury, heart failure, atherosclerosis, and arrhythmias. Copper chelators, such as ammonium tetrathiomolybdate(VI) and DL-Penicillamine, may ease the above cardiovascular diseases by inhibiting the cuproptosis pathway. Oxidative phosphorylation inhibitors may inhibit cuproptosis by inhibiting protein stress response. In conclusion, cuproptosis plays an essential role in cardiovascular disease pathogenesis. Inhibition of cardiovascular cuproptosis is expected to become a potential treatment. Here, we will thoroughly review the molecular mechanisms involved in cuproptosis and its significance in cardiovascular disease. [Display omitted] • Cuproptosis is a copper-dependent and regulated non-apoptotic death mode. • Cuproptosis activates oxidative stress and inhibits ubiquitin-proteasome system to induce cell death. • Cuproptosis plays an important role in cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Based on life cycle assessment (LCA), this paper compares five different methods for food waste treatment. To achieve it, the environmental performance of food waste in Shandong University as a case study is evaluated. The case study indicates that saving food is the ultimate way to reduce environment impact and the distance for transportation also affects a lot. The result of comparison shows that landfill contributes most to climate change, which is about 10 times larger than others. For acidification and eutrophication, incineration shows the worst result 7.77 PAF*m 2 yr. And composting has the largest impact on carcinogens with the result 3.49E-05 DALY. On the whole, the waste treatment technologies are recommended in proper sequence from anaerobic digestion, heat-moisture reaction, composting and incineration to landfill. [ABSTRACT FROM AUTHOR]

• A bionic reactor for methanol steam reforming with tree-shaped channels is proposed. • The reactor upgrades thermal energy of concentrating PV cell to deliver extra power. • Methanol conversion is improved by 12.1 percentage points. • Net solar-electric efficiency of 36.6% and high energy storage capability are obtained. The photovoltaic–thermochemical (PVTC) hybrid system converts thermal energy dissipated by concentrating photovoltaic cells to gain in power generation via the endothermic methanol steam reforming (MSR) reaction. Conventional MSR reactors are challenged by undesirable performances in heat transfer and methanol conversion, impacting the performances of power generation and energy storage of PVTC systems. In this work, an innovative fractal tree-shaped structure is introduced into the flow channels configuration of an MSR reactor to enhance heat transfer performance and methanol conversion. The methanol conversion of the novel reactor is experimentally assessed, which is 12.1 percentage points (relative improvement of 26.5%) higher than that of conventional reactors with serpentine flow channels design. A 3-D multiphysics model of the MSR reactors coupling heat transfer, gas flow, and chemical reaction is developed to reveal the mechanism of methanol conversion improvement. The fractal tree-shaped structure can improve the net solar-electric efficiency of the photovoltaic–thermochemical hybrid system by 5.6–7.5% (up to 36.6%). The efficient solar energy power generation of the PVTC system with energy storage ratio ensures considerable dispatchability for hybrid solar power generation. [ABSTRACT FROM AUTHOR]

Abstract: The detailed chemical structures of three low-pressure (35Torr) premixed laminar furan/oxygen/argon flames with equivalence ratios of 1.4, 1.8 and 2.2 have been investigated by using tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry. About 40 combustion species including hydrocarbons and oxygenated intermediates have been identified by measurements of photoionization efficiency spectra. Mole fraction profiles of the flame species including reactants, intermediates and products have been determined by scanning burner position with some selected photon energies near ionization thresholds. Flame temperatures have been measured by a Pt–6%Rh/Pt–30%Rh thermocouple. A new mechanism involving 206 species and 1368 reactions has been proposed whose predictions are in reasonable agreement with measured species profiles for the three investigated flames. Rate-of-production and sensitivity analyses have been performed to track the key reaction paths governing furan consumption for different equivalence ratios. Both experimental and modeling results indicate that few aromatics could be formed in these flames. Furthermore, the current model has been validated against previous pyrolysis results of the literature obtained behind shock waves and the agreement is reasonable as well. [Copyright &y& Elsevier]

Abstract: An improved chemical kinetic model for the toluene oxidation based on experimental data obtained in a premixed laminar low-pressure flame with vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry (MBMS) techniques has been proposed. The present mechanism consists of 273 species up to chrysene and 1740 reactions. The rate constants of reactions of toluene decomposition, reaction with oxygen, ipso-additions and metatheses with abstraction of phenylic H-atom are updated; new pathways of C4 +C2 species giving benzene and fulvene are added. Based on the experimental observations, combustion intermediates such as fulvenallene, naphthol, methylnaphthalene, acenaphthylene, 2-ethynylnaphthalene, phenanthrene, anthracene, 1-methylphenanthrene, pyrene and chrysene are involved in the present mechanism. The final toluene model leads to an overall satisfactory agreement between the experimentally observed and predicted mole fraction profiles for the major products and most combustion intermediates. The toluene depletion is governed by metathese giving benzyl radicals, ipso-addition forming benzene and metatheses leading to C6H4CH3 radicals. A sensitivity analysis indicates that the unimolecular decomposition via the cleavage of a methyl C–H bond has a strong inhibiting effect, while decomposition via C–C bond breaking, ipso-addition of H-atom to toluene, decomposition of benzyl radicals and reactions related to C6H4CH3 radicals have promoting effect for the consumption of toluene. Moreover, flow rate analysis is performed to illustrate the formation pathways of mono- and polycyclic aromatics. [ABSTRACT FROM AUTHOR]

Abstract: An experimental and modeling study of 11 premixed NH3/CH4/O2/Ar flames at low pressure (4.0kPa) with the same equivalence ratio of 1.0 is reported. Combustion intermediates and products are identified using tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry. Mole fraction profiles of the flame species including reactants, intermediates and products are determined by scanning burner position at some selected photon energies near ionization thresholds. Temperature profiles are measured by a Pt/Pt–13%Rh thermocouple. A comprehensive kinetic mechanism has been proposed. On the basis of the new observations, some intermediates are introduced. The flames with different mole ratios (R) of NH3/CH4 (R0.0, R0.1, R0.5, R0.9 and R1.0) are modeled using an updated detailed reaction mechanism for oxidation of CH4/NH3 mixtures. With R increasing, the reaction zone is widened, and the mole fractions of H2O, NO and N2 increase while those of H2, CO, CO2 and NO2 have reverse tendencies. The structural features by the modeling results are in good agreement with experimental measurements. Sensitivity and flow rate analyses have been performed to determine the main reaction pathways of CH4 and NH3 oxidation and their mutual interaction. [Copyright &y& Elsevier]

Abstract: A premixed laminar acetylene/oxygen/argon flame with an equivalence ratio of 2.25 was investigated at low pressure (3.3kPa). The flame structure was measured using molecular-beam mass spectrometry (MBMS) and tunable synchrotron vacuum ultraviolet (VUV) photoionization. Combustion intermediates from m/z =15–146, including many radicals and isomeric species, were identified from the ionization threshold measurements of photoionization efficiency spectra; and their mole fraction profiles were evaluated from the measurements of burner scan at the photon energies near ionization thresholds. Besides, the flame temperature profile was recorded by a Pt/Pt–13%Rh thermocouple. In particular, polyynes (C2n H2, n ⩾2) up to C12H2 were observed in this flame and attracted special concerns. Due to the analogous structural features of polyynes and exponential concentration decay with the increasing molecular weight, these intermediates are concluded to be formed from smaller ones via similar formation channels, which can verify the suggestion of previous investigations. Furthermore, another polyynic family with formula of C n H4 (4⩽ n ⩽10) was detected in this flame. Possible formation channels are discussed for the newly observed polyynic C n H4 intermediates in acetylene flames. [Copyright &y& Elsevier]

Abstract: A slightly sooting premixed ethylbenzene flame with an equivalence ratio of 1.90 was investigated at low pressure (4.0kPa) using molecular-beam mass spectrometry (MBMS) and tunable synchrotron vacuum ultraviolet (VUV) photoionization. Basing on the ionization threshold measurements of photoionization efficiency (PIE) spectra, combustion intermediates up to C19H12 were identified, including a number of radicals and isomeric species. Mole fraction profiles of observed flame species were evaluated from the measurements of burner scan at the photon energies near ionization thresholds. Besides, the flame temperature profile was measured by a Pt/Pt–13%Rh thermocouple. From the intermediate identification and mole fraction measurements, the degradation of ethylbenzene, as well as the formation of some interested polycyclic aromatic hydrocarbons (PAHs), was discussed in detail. It is suggested that the formation of most typical PAHs observed in this work can be related to the H-abstraction/C2H2-addition (HACA) mechanism. Furthermore, the high concentration levels of intermediates in this flame is ascribed to the weak C–C bonds in the sidechain of ethylbenzene, which provides a potential explanation of the high sooting tendencies of ethylbenzene and other monocyclic aromatic fuels with complex sidechain structure. This study is anticipated to be constructive for combustion investigations of aromatic fuels, and the discussion is hoped to be helpful for further modeling studies concerning PAHs formation in combustion process. [Copyright &y& Elsevier]

Abstract: A premixed nitromethane/oxygen/argon flame at low pressure (4.67kPa) has been investigated using tunable vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry. About 30 flame species including hydrocarbons, oxygenated and nitrogenous intermediates have been identified by measurements of photoionization efficiency spectra. Mole fraction profiles of the flame species have been determined by scanning burner position at some selected photon energies. The results indicate that N2 and NO are the major nitrogenous products in the nitromethane flame. Compared with previous studies on nitromethane combustion, a number of unreported intermediates, including C3H4, C4H6, C4H8, C2H2O, C2H4O, CH3CN, H2Cph name="dbnd" />O, C3H3N and C3H7N, are observed in this work. Based on our experimental results and previous modeling studies, a detailed oxidation mechanism including 69 species and 314 reactions has been developed to simulate the flame structure. Despite some small discrepancies, the predictions by the modeling study are in reasonable agreement with the experimental results. [Copyright &y& Elsevier]

Abstract: Two premixed laminar pyrrole/oxygen/argon flames at 3.33 kPa (25 Torr) with equivalence ratios of 0.55 (C/O/N = 1:5.19:0.25) and 1.84 (C/O/N = 1:1.56:0.25) have been investigated using tunable synchrotron photoionization and molecular-beam mass spectrometry techniques. All observed flame species, including some nitrogen-containing intermediates, have been identified by measurements of photoionization efficiency spectra. Mole fraction profiles of species including reactants, intermediates, and products have been determined by scanning burner position at some selected photon energies near ionization thresholds, and flame temperature has been measured by a Pt/Pt–13% Rh thermocouple. The results indicate that N2, NO, and NO2 are the major nitrogenous products, while hydrogen cyanide, isocyanic acid, and 2-propenenitrile are the most important nitrogen-containing intermediates in pyrrole flames. Radicals such as methyl, propargyl, allyl, cyanomethyl, n-propyl, isobutyl, cyclopentadienyl, phenyl, cyclohexyl, phenoxy, and 4-methylbenzyl are observed as well. Moreover, ethenol and methylacrylonitrile are also detected. Reaction pathways involving the major species are proposed. The new results will be useful in developing a kinetic model of nitrogenous compound combustion. [Copyright &y& Elsevier]

Abstract: A comprehensive experimental study of the premixed benzene/oxygen/argon flame at 4.0kPa with a fuel equivalence ratio (ϕ) of 1.78 has been performed with the tunable synchrotron photoionization and molecular-beam sampling mass spectrometry. Isomers of most observed species in the flame have been unambiguously identified by measurements of the photoionization efficiency spectra. Mole fraction profiles of species up to C16H10 have been measured at the selective photon energies near ionization thresholds, and the flame temperature profile is obtained using Pt/Pt–13%Rh thermocouple. Compared with previous studies on benzene flames by Bittner and Howard, and by Defoeux et al., a number of new species are observed in the present work. These new combustion intermediates should be included in the kinetic models of the growth of polycyclic aromatic hydrocarbons (PAHs) and benzene oxidation. Free radicals detected in the flame include CH3, C2H, C2H3, C2H5, C3H, C3H3, C3H5, C4H, C4H3, C4H5, C4H7, C5H3, C5H5, C5H7, C6H5, C6H5O, C7H7, and C9H7. More significantly, isomers of some PAHs have been identified, which should be of importance in understanding the mechanism of soot formation. [Copyright &y& Elsevier]

Abstract The hyporheic zone (HZ), located at the interface of surface and groundwater, is a natural bioreactor for attenuation of chemical contaminants. Engineered HZs can be incorporated into stream restoration projects to enhance hyporheic exchange, with flowpaths optimized to promote biological habitat, water quantity, and water quality improvements. Designing HZs for in-stream treatment of stormwater, a significant source of flow and contaminant loads to urban creeks, requires assessment of both the hydrology and biogeochemical capacity for water quality improvement. Here, we applied tracer tests and high resolution mass spectrometry (HRMS) to characterize an engineered hyporheic zone unit process, called a hyporheic design element (HDE), in the Thornton Creek Watershed in Seattle, WA. Dye, NaCl, and bromide were used to hydrologically link downwelling and upwelling zones and estimate the hydraulic retention time (HRT) of hyporheic flowpaths. We then compared water quality improvements across hydrologically-linked surface and hyporheic flowpaths (3–5 m length; ∼30 min to >3 h) during baseflow and stormflow conditions. We evaluated fate outcomes for 83 identified contaminants during stormflow, including those correlated with an urban runoff mortality syndrome in coho salmon. Non-target HRMS analysis was used to assess holistic water quality improvements and evaluate attenuation mechanisms. The data indicated substantial water quality improvement in hyporheic flowpaths relative to surface flow and improved contaminant removal with longer hyporheic HRT (for ∼1900 non-target compounds detected during stormflow, <17% were attenuated >50% via surface flow vs. 59% and 78% via short and long hyporheic residence times, respectively), and strong contributions of hydrophobic sorption towards observed contaminant attenuation. Graphical abstract Image 1 Highlights • Engineered hyporheic zones (HZs) can treat non-point source pollution in-stream. • Hydraulically linked hyporheic flowpaths were identified with non-reactive tracers. • Hyporheic flow attenuates many organic contaminants detected in urban runoff. • Longer residence times in the HZ promote removal, particularly of polar compounds. • Non-target HRMS data can estimate hydrophobicity to evaluate sorption potential. [ABSTRACT FROM AUTHOR]

Highlight • A concentrating photovoltaic/thermal (C-PV/T) hybrid system is integrated in a biogas plant. • C-PV/T can partly provide the heat and electricity needed by biogas production and upgrading. • Integrating C-PV/T can achieve a positive net present value under the current market conditions. • The capital cost of C-PV/T, the interest rate and the biomethane price are the most critical factors. Abstract Biogas produced from anaerobic digestion processes is considered as an important alternative to natural gas and plays a key role in the emerging market for renewable energy. Aiming at achieving a more sustainable and efficient biomethane production, this work proposed a novel energy system, which integrates concentrating photovoltaic/thermal (C-PV/T) hybrid modules into a biogas plant with chemical absorption for biogas upgrading. The investigated energy system was optimized based on the data from an existing biogas plant, and its techno-economic feasibility was evaluated. Results show that about 7% of the heat consumption and 12% of the electricity consumption of the biogas plant can be covered by solar energy, by using the produced heat in a cascade way according to the operating temperature of different processes. The production of biomethane can also be improved by 25,800 N m3/yr (or 1.7%). The net present value of the integrated system is about 2.78 MSEK and the payback period is around 10 years. In order to further improve the economic performance, it is of great importance to lower the capital cost of the C-PV/T module. [ABSTRACT FROM AUTHOR]

Multivalent effect plays an important role in biological processes, particularly in the specific recognition of virus with its host cell during the first step of infection. Here we report the synthesis of multivalent pentacyclic triterpene grafted on cyclodextrin core and potency of against influenza entry activity. Nine star-shaped compounds containing six, seven and eight pentacyclic triterpene pharmacophore on cyclodextrin scaffold were prepared by way of copper-catalyzed azide-alkyl cycloaddition reaction under microwave activation. Some of the multimers exhibited much potent antiviral activity against H1N1 virus (A/WSN/33), even equivalent or superior to oseltamivir. The most active compound 31 , a heptavalent oleanolic acid- β -cyclodextrin conjugate, shows an up to 125-fold potency enhancement by its IC 50 value over the corresponding monovalent conjugate and oleanolic acid, disclosing a clear multivalent effect. Further studies show that three compounds 31 – 33 exhibited broad spectrum inhibitory activity against other two human influenza A/JX/312 (H3N2) and A/HN/1222 (H3N2) viruses with the IC 50 values at 2.47–14.90 μ M. Most importantly, we found that compound 31, one of the best representative conjugate, binds tightly to the viral envelope hemagglutinin with a dissociation constant of K D = 2.08 μ M, disrupting the interaction of hemagglutinin with the sialic acid receptor and thus the attachment of viruses to host cells. Our study might establish a strategy for the design of new pharmaceutical agents based on multivalency so as to block influenza virus entry into host cells. [ABSTRACT FROM AUTHOR]

Abstract: Lean and rich premixed flames of three different C3-oxygenated hydrocarbons (acetone, n-propanol, and i-propanol) at low pressure have been investigated with tunable synchrotron photoionization and molecular-beam mass spectrometry. Flame species, including isomeric intermediates, are unambiguously identified with measurements of photoionization efficiency spectra by scanning the photon energy. Mole fraction profiles of most observed species are measured by scanning the burner position at selected photon energies near ionization thresholds, and the flame temperature profiles are recorded using a Pt/Pt–13%Rh thermocouple. Compared with previous studies, some new flame species, e.g., vinyl, propargyl, allyl, ethenol, methyl ketene, propenols, ethyl ketene, methyl ethyl ketone, butenols, and 1,3,5-hexatriyne, are detected in this work, which will extend our knowledge of the intermediate pools of oxygenated hydrocarbon combustion. On the other hand, comparisons among chemical structures of these flames have been performed, based on the comprehensive experimental data. It is concluded that different structural features of fuel molecules will cause a lot of variation in intermediate pools, isomeric compositions, and formation channels of flame species, especially for the oxygenated intermediates. Combined with previous research on hydrocarbon flames, analyses of pollutant emissions and soot formation are presented. It is consistent with previous studies that the oxygenated fuels have reduced sooting tendencies and potential emissions of toxic oxygenated by-products. [Copyright &y& Elsevier]

• Screening of oxides for solar thermochemical cycling based on experimentally validated model. • High reduction enthalpy of oxides favors short hydrolysis period and low water demand. • Ceria-based oxides outperform perovskite oxides under practical solar reactor conditions. • Ceria exhibits the best efficiency of 4.4 %–16.2 % for reduction at 1300–1600 °C. • Oxides with higher reduction enthalpy and entropy changes could attain efficiencies of 25 %–30%. Efficient solar-to-fuel conversion is of paramount importance to gauge the competitiveness of solar fuel production methods and technologies. Solar thermochemical cycling (STC) has tremendous potential in this regard, yet the realization of which is critically contingent upon the synergy between the redox oxides and reactors of the STC. The evaluation and screening of redox oxides for practical high-efficiency STC shall take the interactions between the oxide's thermodynamic properties and the reactor's effective mass and energy transport into account. In this study, we assess the STC performance of a selection of benchmark nonstoichiometric oxides (ceria, Zr-doped ceria, and perovskite oxides) from the perspective of material-reactor interaction based on an experimentally validated numerical model. We demonstrate material-specific differences in solar-to-fuel efficiency under practical operating conditions and reveal their close yet inevident connection with the design considerations of STC reactors, in addition to the thermodynamic properties of materials. The results show that the efficiencies of neat and Zr-doped ceria are sensitive to higher reduction temperatures, whereas the efficiencies of selected perovskite oxides are more sensitively limited by the flow rate of water. The findings essentially reveal an underlying yet important interconnection between energy consumption and hydrogen productivity, predominantly governed by the thermodynamic properties of oxides and the operating conditions of reactors. Within the constraints of actual fixed-bed reactor operation, optimization of solar-to-fuel efficiency is conducted at reduction temperatures of 1300–1600 °C. Neat ceria exhibits the highest solar-to-fuel efficiency of 4.4% for reduction at 1300 °C and 16.2% at 1600 °C. The perovskite oxides exhibit notably lower solar-to-fuel efficiency than neat and Zr-doped ceria, which is correlated with their lower reduction enthalpy change, higher specific heat, and greater water consumption. This study further investigates the thermodynamic properties of ideal hypothetical oxides to enhance the solar-to-fuel efficiency in practical applications. The solar-to-fuel efficiency of the idealized ceria-based oxide, which has higher reduction enthalpy and entropy changes than those of neat ceria, can reach up to 30.6% (without heat recovery). This study provides new thermodynamic insights into the material design and screening for efficient STC reactors and systems. [ABSTRACT FROM AUTHOR]

Efficient energy utilization and decarbonization of energy systems are of paramount importance in tackling global climate change. A novel distributed energy system is proposed, integrating solar photovoltaics, methanol thermochemistry, solid oxide fuel cells, gas turbines, and CO 2 capture. Methanol is reformed by photovoltaic waste heat to produce solar hydrogen-rich syngas, which is then efficiently converted to electricity by solid oxide fuel cells. High-purity CO 2 is separated from the anode exhaust gas containing only CO 2 and H 2 O through low-energy penalty separation via condensation of H 2 O, and is subsequently compressed for storage. Analysis demonstrates that the proposed system outperforms the reference system with parabolic trough solar collectors. The total electrical efficiency of the new system reaches 51.73%, surpassing that of the reference system by 5.02 percentage points, while solar-to-electricity efficiency improves by 19.69%. The overall exergy efficiency of the proposed system reaches 57.41%. The levelized cost of electricity and cost of CO 2 avoided for the proposed system are 0.1163 $/kWh and 29.87 $/t, respectively, and the dynamic payback period is only 4.5 years. Sensitivity analyses indicate outstanding power generation performance, excellent CO 2 reduction potential, and wide adaptability for regional applications. • A novel photovoltaic-thermochemical and SOFC-based distributed system is proposed. • The system realizes flexible storage and release of solar energy and CO 2 capture. • The system waste heat is fully utilized to enable combined heat and power generation. • Comprehensive thermodynamics, environmental, and economic assessment. • Attain 51.73% electrical efficiency with excellent economic and environmental feasibility. [ABSTRACT FROM AUTHOR]

Endothelial dysfunction induced by oxidative stress is an early predictor of atherosclerosis, which can cause various cardiovascular diseases. The glycocalyx layer on the endothelial cell surface acts as a barrier to maintain endothelial biological function, and it can be impaired by oxidative stress. However, the mechanism of glycocalyx damage during the development of atherosclerosis remains largely unclear. Herein, we established a novel strategy to address these issues from the glycomic perspective that has long been neglected. Using countercharged fluorescence protein staining and quantitative mass spectrometry, we found that heparan sulfate, a major component of the glycocalyx, was structurally altered by oxidative stress. Comparative proteomics and protein microarray analysis revealed several new heparan sulfate-binding proteins, among which alpha-2-Heremans-Schmid glycoprotein (AHSG) was identified as a critical protein. The molecular mechanism of AHSG with heparin was characterized through several methods. A heparan analog could relieve atherosclerosis by protecting heparan sulfate from degradation during oxidative stress and by reducing the accumulation of AHSG at lesion sites. In the present study, the molecular mechanism of anti-atherosclerotic effect of heparin through interaction with AHSG was revealed. These findings provide new insights into understanding of glycocalyx damage in atherosclerosis and lead to the development of corresponding therapeutics. [Display omitted] [ABSTRACT FROM AUTHOR]

• A catalyst design method using synergistic effects among components was developed. • A group of favorable catalysts were designed using new method. • The catalytic performance was analyzed and improvement was disclosed. • A PVTC system was developed to validate the benefits of the catalysts in application. Nanocatalysts of compound metal oxides (La 2 CuO 4) x (CNZ-1) 1−x (x = 0.3, 0.5, 0.7) were prepared. Steam reforming of methanol (SRM) over these nanocatalysts was experimentally studied at a H 2 O/methanol molar ratio of 1.6. The results showed that the methanol solution catalyzed by all catalysts synthesized in this work could be completely converted into H 2 , CO 2 and a small amount of CO below a reaction temperature of 270 °C with a liquid hourly space velocity (LHSV) of 1.2 ml/(g·h). The catalysts of La 2 CuO 4 and CuO/ZnO/Al 2 O 3 were tested under the same operating conditions. Compared with La 2 CuO 4 , LCOx-CNZ showed better performance with a higher methanol conversion rate and H 2 yield. Conversely LCO5-CNZ had better CO and H 2 selectivity compared with CuO/ZnO/Al 2 O 3. LCO3-CNZ showed good competitiveness in all four above aspects when operated at 150–270 °C. It could be concluded that LCOx-CNZ with special structures provided a significant improvement in catalytic performance of SRM benefiting from the synergistic effect among La 2 CuO 4 and CuZnAl oxides. Thermodynamics analysis and experiments using a hybrid power generation system were applied with the above catalysts. Under direct normal irradiation at 915 W/m2 and a reaction temperature of 230 °C, LCO3-CNZ showed 9.7% higher H 2 yield and 3.9% higher net solar power generation efficiency than did Cu/Zn/Al oxides. [ABSTRACT FROM AUTHOR]

Assessing the impact of chemical contaminants on aquatic ecosystem health remains challenging due to complex exposure scenarios and the myriad of impact metrics to consider. To expand the breadth of compounds monitored and evaluate the potential hazard of environmental mixtures, cell-based bioassays (estrogen receptor alpha (ERα) and aryl hydrocarbon receptor (AhR)) and non-targeted chemical analyses with high resolution mass spectrometry (NTA-HRMS) were used to assess the quality of ∼70 marine sediment samples collected from 5 distinct coastal and offshore habitats of the Southern California Bight. AhR responses (<0.12–4.5 ng TCDD/g dry weight) were more frequently detectable and more variable than for ERα (<0.1–0.5 ng E2/g dry weight). The range of AhR and ERα responses increased by habitat as follows: Channel Islands < Mid-shelf < Marinas < Ports < Estuaries. The narrow range and magnitude of ERα screening response suggested limited potential for estrogenic impacts across sediments from all 5 habitats. The AhR response was positively correlated with total PAH and PCB concentrations and corresponded with a chemical score index representing the severity of metal and organic contamination. NTA-HRMS fingerprints generated in positive electrospray ionization mode were clearly distinguishable among coastal vs. offshore samples, with the greatest chemical complexity (n = 982 features detected) observed in estuarine sediment from a highly urbanized watershed (Los Angeles River). The concordance and complementary nature of bioscreening and NTA-HRMS results indicates their utility as holistic proxies for sediment quality, and when analyzed in conjunction with routine targeted chemical monitoring, show promise in identifying unexpected contaminants and novel toxicants. [Display omitted] • First large-scale application of cell bioassay and non-targeted chemical analyses to assess coastal and marine sediments. • The aryl hydrocarbon receptor bioassays provided a means for efficient screening of sediment quality. • Cell bioassays coupled with non-targeted chemical analyses showed potential to identify unknown or unexpected toxicants. [ABSTRACT FROM AUTHOR]

Highlights: [•] PCDD/Fs, PCBs, HxCBz, PeCBz and polychlorophenols in 2,4-D were analyzed. [•] Relationship between the precursors and UPPOPs was discussed. [•] Emissions of PCDD/Fs and dl-PCBs in China were evaluated. [•] A suggestion on 2,4-D production was developed to reduce UPPOPs emission. [Copyright &y& Elsevier]

Abstract: In order to determine the effects of oxygenates on the fuel combustion, the experiments reported here investigated the premixed n-heptane flame chemistry. Heptane typifies the large alkanes that comprise the bulk of most hydrocarbon fuels. The specific flames were low-pressure (25Torr), laminar, premixed flames of n-heptane/oxygen/argon and n-heptane/oxygenate/oxygen/argon at an equivalence ratio of 1.0. Two different fuel oxygenates (i.e. MTBE and ethanol) were tested, these are the main oxygenates used to improve motor vehicle fuel properties. The experiment was performed with tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam sampling mass spectrometry. Major species on the centerline of each flame were identified by measurements of the photoionization mass spectrum and photoionization efficiency (PIE) spectra. Mole fraction profiles of these species were derived at the selected photon energies near the ionization thresholds. A large amount of oxygenated intermediates was detected in the oxygenate containing flames. The species measurements indicated that MTBE and ethanol enhanced the heptane oxidation via different routes, and reduced the mole fractions of aromatics and cycloalkenes in varying degrees. The results are a useful databases for testing detailed chemical kinetic mechanism of fuel decomposition. [Copyright &y& Elsevier]

Abstract: This study was performed with the use of tunable vacuum ultraviolet (VUV) lasers for molecular beam sampling mass spectrometry (MBMS) to detect the intermediates of a premixed n-heptane/oxygen/argon laminar low-pressure flame. In this experiment, 24 intermediate species were identified and quantified by the photoionization mass and efficiency spectra at a stoichiometric mixture of n-heptane/oxygen highly diluted by argon gas. The mole fraction profiles of these species at different flame positions are presented. The results show that the main intermediates are ketone and ether in the initial combustion period and these species then further oxidize to hydrocarbons. Of all the species, the concentrations of ethylene and polycyclic aromatic hydrocarbons (PAHs) are the highest concentration up to 10−2 and the lowest concentration to 10−5 in the mole fraction, respectively, at selective flame position. In addition, alkine like propyne exhibits very similar mole fraction profiles with that of benzene in the n-heptane flame. The results provide the strong evidence that benzene production correlates to alkine production in the flame and reinforces, at least qualitatively, the role of propyne species in the benzene formation mechanism. Finally, the distribution of 24 typical species in the flame is correlated with temperature, which is important in establishing the oxidation mechanism of hydrocarbon fuels. [Copyright &y& Elsevier]

Synchrotron radiation offers important advantages with the use of tunable vacuum ultraviolet (VUV) lasers for molecular beam sampling mass spectrometry (MBMS). These advantages include superior signal-to-noise, soft ionization, and access to photon energies outside the limited tuning ranges of current VUV laser sources. Combining MBMS with tunable synchrotron radiation photoionization, two similar types of fuels, gasoline/oxygen and gasoline/MTBE/oxygen in low-pressure premixed laminar flame were investigated. Photoionization efficiency (PIE) measurements were used to identify the intermediates isomers within flame. The two combustion processes are discussed by comparing the intermediates and their spatial profiles within the two kinds of flame mentioned above. [Copyright &y& Elsevier]

Abstract: Laminar premixed low-pressure flames fueled by either one of the four isomers of butanol were investigated by a molecular-beam photoionization mass spectrometer using vacuum ultraviolet (VUV) synchrotron radiation as the ionization source. The photoionization efficiency (PIE) spectra of most flame intermediates were measured between 7.75 and 11.00 eV. By comparing the resulting PIE spectra to known ionization energies (IEs) or known PIE spectra of pure substances, most hydrocarbon and oxygenated combustion intermediates, including some radicals, in the mass range from to 106 were assigned and identified in the four butanol flames. The results show that the higher-mass oxygenated species in butanol flames are strongly affected by the fuel structure, while many hydrocarbon isomers appear almost independent of the fuel structure. The respective dissociation mechanisms of the fuels, including complex fission, simple fission, and H-atom abstraction, are in good agreement with previous results from nonpremixed butanol flames. [Copyright &y& Elsevier]