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Entrepreneurship is often associated with masculinity as well as symbolic and actual male bodies, which creates discursive and material constraints for women entrepreneurs. This study synthesizes an intersectional reinscription analysis and new materialist approaches to agency to explore 34 mainland Chinese women entrepreneurs' identity construction or boundary-makings in and beyond their work encounters with various actors. Materializing through participants' narratives are abstract, intangible 'ideas/ideals' that become real 'things' capable of stirring/halting/altering women's entrepreneurial activity, including 'the feminine,' 'family harmony,' 'stable job,' and 'Chinese traditions.' Already within and as open-ended relations, these nonhuman agents also get reconfigured in encountering women's entrepreneurial enactments, whereby situated systems of power (apart from gender and occupation) also arise. Practically, this study maps potential sites of intervention in gendered entrepreneurship ecosystems and highlights cultural, work-life, and political insights shown through participants' boundary-making practices. [ABSTRACT FROM AUTHOR]

The association between composite dietary antioxidant index (CDAI) and asthma remains unclear. Our study aimed to investigate the association of CDAI with asthma in children aged 3–18 years in the United States. Cross-sectional analyses were carried out on 18,118 children aged 3–18 years old. Data was obtained from the National Health and Nutrition Examination Survey (NHANES) conducted between 2003 and 2020. The Composite Dietary Antioxidant Index (CDAI) was measured by assessing the consumption of six dietary antioxidants (vitamin A, vitamin C, vitamin E, zinc, selenium and carotenoids). The association between CDAI and asthma was explored using multivariate weighted logistic regression, subgroup analyses, and sensitivity analyses. Among the 18,118 participants, 2045 (11.3%) reported a diagnosis of asthma by a healthcare provider. In both the crude and adjusted models, the odds ratios (ORs) for asthma with CDAI were not significant. Specifically, in the fully adjusted model, the OR for T2 was 0.98 (95% CI 0.83, 1.17) and the OR for T3 was 1.00 (95% CI 0.76, 1.31). Subgroup analyses by sex, age and BMI category also showed no significant associations. Sensitivity analyses, including weighted logistic multivariate analyses adjusting for family history of asthma, confirmed the absence of a significant association between CDAI and asthma. Our study showed no significant association between CDAI and asthma in children and adolescents. [ABSTRACT FROM AUTHOR]

The identity of women entrepreneurs illuminates discursive struggles given the masculine norms of entrepreneurship. Applying relational dialectics theory (RDT), this study explored competing discourses surrounding understudied Chinese women entrepreneurs and the interplay of their identification and masculine discourses. I conducted narrative interviews with 34 Chinese women. Contrapuntal analysis of this non-Western data however identified that discursive struggles happened when voicing/speaking/expressing was not prioritized. Hence, I turned to new materialist perspectives to (re)work discourses as boundary-making practices producing local things/beings-in-relations and agents as anyone/anything participating in the dynamism. In two themes as competing discourses (discourses of misalignment vs. legitimacy), I focused on local movements and interferences when/where women in their entrepreneurial becoming encountered various human and nonhuman agents, and therefore demonstrated how discursive struggles involved various bodies/things, more than just talk/voices. Ultimately, this study diffracted RDT by engaging with new materialisms and proposing a new uttered-embodied dimension of discursive struggles. [ABSTRACT FROM AUTHOR]

Numerous studies have demonstrated the pivotal roles of intestinal microbiota in many physiopathological processes through complex interactions with the host. As a unique period in a woman's lifespan, pregnancy is characterized by changes in hormones, immunity, and metabolism. The gut microbiota also changes during this period and plays a crucial role in maintaining a healthy pregnancy. Consequently, anomalies in the composition and function of the gut microbiota, namely, gut microbiota dysbiosis, can predispose individuals to various pregnancy complications, posing substantial risks to both maternal and neonatal health. However, there are still many controversies in this field, such as "sterile womb" versus "in utero colonization." Therefore, a thorough understanding of the roles and mechanisms of gut microbiota in pregnancy and its complications is essential to safeguard the health of both mother and child. This review provides a comprehensive overview of the changes in gut microbiota during pregnancy, its abnormalities in common pregnancy complications, and potential etiological implications. It also explores the potential of gut microbiota in diagnosing and treating pregnancy complications and examines the possibility of gut‐derived bacteria residing in the uterus/placenta. Our aim is to expand knowledge in maternal and infant health from the gut microbiota perspective, aiding in developing new preventive and therapeutic strategies for pregnancy complications based on intestinal microecology. Highlights: Pregnancy complications critically affect maternal and child health, necessitating urgent research and therapeutic strategies to reduce health and socioeconomic impacts.Gut microbiota dysbiosis in patients with various pregnancy complications acts as both a causal factor and a contributor to these conditions.Gut microbiota‐derived metabolites are involved in various pathophysiological pathways closely related to the pathogenesis of pregnancy complications, including intestinal barrier permeability, inflammatory responses, and glucose and lipid metabolism.Emerging therapeutic strategies based on gut microbes show potential in treating pregnancy complications, yet there is a lack of evidence from randomized controlled trials (RCTs) to substantiate this approach. [ABSTRACT FROM AUTHOR]

Objective: this study aimed to identify the relationships between gut microbiota, metabolism, and non-small cell lung cancer (NSCLC) treatment outcomes, which are presently unclear. Methods: in this single-center prospective cohort study, we investigated changes in the gut microbiota and serum metabolite profile in 60 patients with NSCLC after four cycles of anticancer therapy. Results: The microbial landscape of the gut exhibited a surge in Proteobacteria and Verrucomicrobiota populations, alongside a decline in Firmicutes, Actinobacteriota, and Bacteroidota. Furthermore, a significant shift in the prevalence of certain bacterial genera was noted, with an increase in Escherichia/Shigella and Klebsiella, contrasted by a reduction in Bifidobacterium. Metabolomic analysis uncovered significant changes in lipid abundances, with certain metabolic pathways markedly altered post-treatment. Correlation assessments identified strong links between certain gut microbial genera and serum metabolite concentrations. Despite these findings, a subgroup analysis delineating patient responses to therapy revealed no significant shifts in the gut microbiome's composition after four cycles of treatment. Conclusions: This study emphasizes the critical role of gut microbiota changes in NSCLC patients during anticancer treatment. These insights pave the way for managing treatment complications and inform future research to improve patient care by understanding and addressing these microbiota changes. [ABSTRACT FROM AUTHOR]

Memorable messages oftentimes are associated with hope, can foster anticipatory resilience prior to the experience of disruptive events, and can buffer the negative impact of adverse experiences on mental health. However, associations among memorable messages, engagement in resilience processes, and mental health have not been examined. Drawing from the communication theory of resilience (CTR), analyses of data from 262 Chinese adults suggested that memorable messages provided a sense of agency and pathways – two interrelated but distinct components of dispositional hope – and functioned as a form of anticipatory resilience that was positively associated with outcomes of coping with disruptive life events including mental health, posttraumatic growth, and meaning in life. These associations were mediated by the extent to which individuals engaged in change- and continuity-related resilience processes as outlined in CTR. Findings offer theoretical implications for memorable message and resilience research as well as practical implications for communicative strategies that can cultivate anticipatory resilience, promote positive adaptation, learning, and reflection, and mitigate the negative effects that disruptive events can have on mental health. [ABSTRACT FROM AUTHOR]

Tracking ambiguity and multipath are two serious threats in processing binary offset carrier (BOC) signals that are widely used in global navigation satellite systems (GNSS). Three-loop tracking methods, such as dual binary phase-shift keying tracking (DBT), use a delay lock loop (DLL), a phase lock loop (PLL), and a subcarrier PLL (SPLL) to track the code, carrier, and subcarrier, respectively, thus solving the tracking ambiguity problem. However, the multipath remains an important factor in the ranging performance deterioration of these tracking methods. Using the offset correlator (OC) technique in the SPLL can effectively mitigate subcarrier multipath errors, but it substantially raises thermal noise errors. To solve this contradiction, this paper proposes a prompt-assisted-offset correlator (PAOC) technique that combines the prompt and offset correlators in a complementary way to mitigate multipath for BOC signals. Compared with the original OC technique, the PAOC technique has less thermal noise performance loss. Moreover, this paper discovers and quantifies the interaction between carrier and subcarrier multipath errors by analyzing the coupling effect between SPLL and PLL. Most multipath mitigation methods for BOC signals ignore the carrier multipath in the PLL, so their subcarrier multipath performance is not optimal. Thus, this paper further proposes applying the PAOC technique in both PLL and SPLL to mitigate carrier and subcarrier multipath errors simultaneously. Theoretical analysis and experimental results demonstrate that the proposed method can significantly improve the multipath performance with small noise performance loss. [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]

In U.S. Pacific Northwest coho salmon (Oncorhynchus kisutch), stormwater exposure annually causes unexplained acute mortality when adult salmon migrate to urban creeks to reproduce. By investigating this phenomenon, we identified a highly toxic quinone transformation product of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), a globally ubiquitous tire rubber antioxidant. Retrospective analysis of representative roadway runoff and stormwater-affected creeks of the U.S. West Coast indicated widespread occurrence of 6PPD-quinone (<0.3 to 19 micrograms per liter) at toxic concentrations (median lethal concentration of 0.8 ± 0.16 micrograms per liter). These results reveal unanticipated risks of 6PPD antioxidants to an aquatic species and imply toxicological relevance for dissipated tire rubber residues. [ABSTRACT FROM AUTHOR]

We retrospectively investigated the relationship between cardiopulmonary exercise testing (CPET) parameters and coronary microvascular dysfunction (CMD) using a novel angiography-based index of microcirculatory resistance (AccuIMR) in patients with ST-elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) with complete revascularization. In 418 patients, the culprit vessel AccuIMR was calculated after successful primary PCI. CPET was conducted 44.04 ± 19.28 days after primary PCI. Overall, 157 patients (37.6%) showed elevated AccuIMR (> 40 U) in the culprit vessels. The LVEF was significantly lower in the CMD group than in the Non-CMD group. The CMD group showed worse results in VO2peak, peak O2-pulse, and VE/VCO2 slope than the Non-CMD group. Spearman correlation analysis suggested that VO2peak (r = -0.354), peak O2-pulse (r = -0.385) and VE/VCO2 slope (r = 0.294) had significant linear correlations with AccuIMR (P < 0.001). Multivariable logistic regression analysis showed that AccuIMR was the independent predictor of reduced VO2peak and elevated VE/VCO2 slope. The proportions of positive and equivocal ECG results and early O2-pulse flattening in the CMD group were significantly higher than those in the Non-CMD group, and AccuIMR was the only independent predictor of these ischemia-relating indicators, suggesting that patients with CMD had significant noninvasively detectable myocardial ischemia. [ABSTRACT FROM AUTHOR]

Applying communication theory of resilience (CTR), this study examines how women leaders in China's politics enact resilience throughout their long career journey. We draw upon in-depth interviews to analyze the storied experiences of participants' career development. Previous studies focus on the separate processes of CTR. We demonstrate how and when individuals interweave several processes through identifying resilience enactment in the following areas: resilience in resistance, resilience in (re)alignment, resilience in networks. Additionally, we propose the concept of subjective resilience resource as a new element of CTR by locating resilience in transformative achievements. Our findings contribute to CTR, bringing an additional way of conceptualizing the dynamics of resilience processes. Moreover, our study adds to the different contexts in which CTR offers an explanatory framework for how individuals and groups enact resilience to adapt to and transform their changing circumstances. [ABSTRACT FROM AUTHOR]

Pollutants transported in urban stormwater runoff induce pervasive water quality degradation in receiving waters. To accurately characterize stormwater quality and treatment system performance across the range of possible contaminant characteristics, comprehensive multi-residue analytical methods are necessary. Here, we developed a solid-phase extraction (SPE) and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method to quantify representative stormwater-derived organic contaminants across multiple chemical classes, including vehicle-related chemicals, corrosion inhibitors, industrial chemicals, pesticides, pharmaceuticals and personal care products, and antioxidants. Extraction conditions, isotope-labeled internal standards, and LC-MS/MS parameters were optimized to enhance recovery, minimize matrix effects, and maximize selectivity and sensitivity. The developed method was sensitive (method quantification limits < 10 ng/L for > 80% of selected analytes) and accurate (mean relative recoveries in the range of 70–130%, with relative standard deviations < 25% for 77% of the analytes) for most of the analytes. The method was used to analyze samples collected from nine urban watersheds during a storm event; 62% of the 39 analytes were detected at least once at concentrations up to 540 ng/L (1,3-diphenylguanidine). Spatial trends in detection and concentration were observed for vehicle-related and industrial chemicals that correlated with vehicle traffic. Total concentrations of pesticides suggested that residential uses could be more important sources than agriculture. This study illustrates the pervasive occurrence of a wide variety of stormwater-derived chemicals in urban receiving waters and highlights the need to better understand their environmental fate and ecological implications. [ABSTRACT FROM AUTHOR]

This paper proposes a hybrid adaptive ant colony algorithm (HAACA) to realize product family multi-objective optimization design through scale-based product platform theory model. The Pareto-optimal solution was obtained via HAACA, and then the fuzzy optimization method is presented to extract the optimal solution of multi-objective optimization problem. The multi-objective optimization method was carried out in two stages. In the first stage, each product is optimized independently via HAACA and the product platform constant parameter and its value is obtained according to the change ratio of design variables. In the second stage, the scaling variables of each product are solved via HAACA based on the optimization objectives improving the performance in constraint of restrictions and the best compromise solution is extracted based on fuzzy optimization method. [ABSTRACT FROM AUTHOR]

Localization based on single-line lidar is widely used in various robotics applications, such as warehousing, service, transit, and construction, due to its high accuracy, cost-effectiveness, and minimal computational requirements. However, challenges such as LiDAR degeneration and frequent map changes persist in hindering its broader adoption. To address these challenges, we introduce the Contribution Sampling and Map-Updating Localization (CSMUL) algorithm, which incorporates weighted contribution sampling and dynamic map-updating methods for robustness enhancement. The weighted contribution sampling method assigns weights to each map point based on the constraints within degenerate environments, significantly improving localization robustness under such conditions. Concurrently, the algorithm detects and updates anomalies in the map in real time, addressing issues related to localization drift and failure when the map changes. The experimental results from real-world deployments demonstrate that our CSMUL algorithm achieves enhanced robustness and superior accuracy in both degenerate scenarios and dynamic map conditions. Additionally, it facilitates real-time map adjustments and ensures continuous positioning, catering to the needs of dynamic environments. [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]

• 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 impact of a typical municipal solid waste incinerator (MSWI) on polychlorinated naphthalene (PCN) concentrations in surrounding soil was studied. We collected 6 stack gas samples from the MSWI and 21 soil samples from sampling sites at distances of between 300 and 1700m from the MSWI stack. Total dl-PCN (dioxin-like PCN) concentrations in the stack gas samples ranged from 6898 and 89,032pgm−3, with a mean value of 36,241pgm−3. The total dl-PCN concentrations in the soil samples ranged from 30.35 to 280.9pgg−1, with a mean value of 87.03 and a median value of 70.32pgg−1, while the TEQ values were between 7.7 and 130.2fg TEQ g−1, with a mean value of 41.12fg TEQ g−1 and a median value of 31.52fg TEQ g−1. The PCN homologue patterns and the results of Principal Component Analysis suggested that the MSWI may be a source of PCNs in the soils. A contour map, created using an ordinary Kriging interpolation technique, showed that a limited area (≤1000m radius) surrounding the MSWI was influenced by the emissions from the MSWI. Furthermore, an exponential function equation was proposed to quantify the relationship between TEQs of PCNs and the distance from the stack. [Copyright &y& Elsevier]

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: The total oxidation of C2H2, C3H6, C3H8, n-C4H8, n-C4H10 and i-C4H10 was studied in a monolithic flow reactor under temperature-programmed mode and highly diluted conditions. The non-catalytic combustion of the investigated hydrocarbons leads to a substantial formation of CO and traces of methane at intermediate temperatures. This drawback was suppressed upon the deposition of a thin layer of Co3O4 on the monolith and all investigated hydrocarbons tend to light off at 250–290°C. The apparent activation energy was found to exhibit a linear correlation with the C–H bond dissociation energy, indicating that the C–H activation is still the rate-limiting step. [Copyright &y& Elsevier]

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: 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]

Polycyclic aromatic nitrogen heterocycles, or azaarenes, normally co-occur with polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. We recently reported that nontarget analysis using high resolution mass spectrometry of samples from four PAH-contaminated sites revealed a previously unrecognized diversity and abundance of azaarene isomers and their methylated derivatives. Here we evaluated their biodegradability by natural microbial communities from each site in aerobic microcosm incubations under biostimulated conditions. The removal of total quantifiable azaarenes ranged from 15 to 85%, and was related to the initial degree of weathering for each sample. While three-ring azaarenes were readily biodegradable, the five-ring congeners were the most recalcitrant. Microbial-mediated removal of four-ring congeners varied for different isomers, which might be attributed to the position of the nitrogen atom that also influences the physicochemical properties of azaarenes and possibly the susceptibility to transformation by relevant microbial enzymes. The presence of methyl groups also influenced azaarene biodegradability, which decreased with increasing degree of methylation. Several oxidation products of azaarenes were detected, including ketones and dioxygenated derivatives of three- and four-ring compounds. Our results indicate the susceptibility of some azaarenes to bioremediation, while suggesting the potential implications for risk from the persistence of less-biodegradable isomers and the formation of oxidized-azaarene derivatives. Unlabelled Image • Fate of polycyclic aromatic N -heterocycles assessed in four PAH-contaminated soils. • 8 series of congeners analyzed by nontarget screening and mass defect filtering. • Biodegradability varied as a function of molecular weight and degree of methylation. • Selective degradation was observed between isomers of the same congener group. • Nontarget analysis identified the transient accumulation of PANH-oxidation products. [ABSTRACT FROM AUTHOR]

Asymmetrically coordinated single‐atom catalysts are attractive for the implementation of high‐performance lithium–sulfur (Li─S) batteries. However, the design principle of the asymmetric coordination that can efficiently promote bidirectional conversion of polysulfides has not been fully realized. Herein, a series of Co─N3X1 (X refers to F, O, Cl, S, or P) configurations are established, and theoretically unravel that the relative electronegativity value (REV) can be used as an index parameter for characterizing the catalytic activity. By virtue of enhanced chemical affinity with sulfur species and lowered Li2S decomposition, chlorine‐atom‐constructed asymmetric configurations with an optimal REV exhibit stronger catalytic effect to inhibit shuttling. Such a REV‐related catalytic effect is termed as REV effect. Following this principle, a novel single‐atom catalyst with dominated Co─N3Cl1 configuration is successfully synthesized through an inside‐out thermal reaction strategy and used as a modified layer on the cathode‐side separator. Interestingly, the assembled Li─S batteries exhibit quite high rate capacity (804.3 mAh g−1 at 5.0 C), durable cyclability (0.023% capacity decay per cycle), and competitive areal capacity (7.0 mAh cm−2 under 7.5 mg cm−2 sulfur loading and lean electrolyte). The guideline provided in this work gives impetus to the pursuit of highly efficient single‐atom catalysts for practical Li─S batteries. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Previous studies have shown that pretreatment with thapsigargin (TG), a cellular stress inducer, produced potent protective actions against various pathologic injuries. So far there is no information on the effects of TG on the development of bacterial sepsis. Using lipopolysaccharides- and cecal ligation/puncture-induced sepsis models in mice, we demonstrated that preconditioning with a single bolus administration of TG conferred significant improvements in survival. The beneficial effects of TG were not mediated by ER stress induction or changes in Toll-like receptor 4 signaling. In vivo and in cultured macrophages, we identified that TG reduced the protein production of pro-inflammatory cytokines, but exhibited no significant effects on steady state levels of their transcriptions. Direct measurement on the fraction of polysome-bound mRNAs revealed that TG reduced the translational efficiency of pro-inflammatory cytokines in macrophages. Moreover, we provided evidence suggesting that repression of the mTOR (the mammalian target of rapamycin) signaling pathway, but not activation of the PERK (protein kinase R-like endoplasmic reticulum kinase)-eIF2α (eukaryotic initiation factor 2α) pathway, might be involved in mediating the TG effects on cytokine production. In summary, our results support that pharmacological preconditioning with TG may represent a novel strategy to prevent sepsis-induced mortality and organ injuries. [ABSTRACT FROM AUTHOR]

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]

Nanoplastics, owing to their small particle size, pose a significant threat to creatures, deserving heightened attention. Numerous studies have investigated microplastics pollution and their removal efficiency in drinking water treatment plants, none of which have involved nanoplastics due to lacking a suitable analytical method. This study introduced a feasible method of combing AFM-IR and Pyr-GC/MS to identify and quantify nanoplastics (20–1000 nm) for a preliminary understanding of their fate during drinking water treatment processes. Resolving of chemical functional groups and pyrolysis products from AFM-IR and Pyr-GC/MS data demonstrated the presence of PE and PVC nanoplastics in this drinking water treatment plant. The initial influent abundances of PE and PVC nanoplastics were 0.86 μg/L and 137.31 μg/L, with subsequent increase to 4.49 μg/L and 208.64 μg/L in ozonation contact tank unit. Then a gradual decreasing was observed along water process, achieving 98.4% removal of PE nanoplastics and 44.0% removal of PVC nanoplastics, respectively. Although this drinking water treatment plant has exhibited a certain level of nanoplastics removal efficiency, particular attention should be directed to the oxidation unit, which appears to be a significant source of nanoplastics. This study will lay a foundation for revealing nanoplastics pollution in the environment. [Display omitted] • A combined method of AFM-IR and pyr-GC/MS was proposed for nanoplastics analysis. • Both PE and PVC nanoplastics were identified in this drinking water plant. • The drinking water plant can remove nanoplastics to some extent. • Ozonation unit serves as source of nanoplastics in drinking water plant. [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]

The impact of a typical municipal solid waste incinerator (MSWI) on polychlorinated biphenyl (PCB) concentrations in the surrounding soil was studied. Six stack gas samples were taken from the MSWI and 21 soil samples were collected from sampling sites between 300 and 1700 m from the MSWI stack. The total (PCB) concentrations of dioxin-like (dl) PCBs and indicator PCBs in the stack gas samples were between 3.41 and 34.3 ng/m 3 , and the corresponding toxic equivalents (TEQs) ranged from 4.45 to 66.9 pg WHO-TEQ/m 3 , with a mean of 28.6 pg WHO-TEQ/m 3 . A total of 2.43 g WHO-TEQ of PCBs per year was calculated to be released into the environment from MSWIs in China. The PCB concentrations in the soil samples ranged from 28.0 to 264.4 pg/g, with mean and median values of 127.6 and 127.7 pg/g, respectively, while the TEQ values were between 0.020 and 0.18 pg WHO-TEQ/g, with mean and median values of 0.074 and 0.062 pg WHO-TEQ/g, respectively. Comparing this study with other studies performed around the world suggest that PCB emission from incinerators has a critical influence on PCB concentrations in the surrounding soil. An exponential function equation is proposed, which indicates a clear decline in PCB concentrations with increasing distance from the stack. A contour map created using an ordinary kriging interpolation technique showed that a limited area (≤ 1250 m radius) from the stack was clearly influenced by PCB emission from the MSWI. [ABSTRACT FROM AUTHOR]

Plasma-based technology is of great importance for a range of industrial applications. However, due to the complexity of gas-phase and surface chemical reactions, the underlying plasma chemistry is still poorly understood, leading to a growing demand for experimental setups on plasma diagnostics. In this paper, we report an apparatus that combines tunable synchrotron vacuum ultraviolet (VUV) photoionization with molecular-beam mass spectrometry for detecting ionic and neutral species formed in the processes of plasma discharge. The products including reactive intermediates such as enols can be identified unambiguously with the measurements of photoionization mass spectrometry (PIMS) and photoionization efficiency spectra. The tunable VUV PIMS has been proven as an ideal and sensitive tool for a comprehensive understanding of plasma chemistry. [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]

Many concrete structures, such as high concrete dams and deep tunnels, running perennially under the high water pressure condition, are prone to hydraulic fracturing failure. In this paper, a calculation method of water pressure within cracks is proposed, which can reflect the coupling relationship between water flow in cracks and structure deformation. Meanwhile, a crack propagation criterion of hydraulic fracture is proposed, which can be used to analyze the mixed-mode crack propagation problems considering the high water pressure within crack. Based on the theories of seepage and fracture mechanics, a new coupling analysis model for simulating the hydraulic fracturing in concrete structures is presented by using the element-free method (EFM), and the coupling analysis program (CSWF. for) is developed. Then, this analysis model is verified against two numerical examples, and the numerical results have good agreement with the corresponding the law of tests. Finally, the proposed model is applied to simulate hydraulic fracturing in a high concrete gravity dam. Results show that the crack is developed toward the bottom and the downstream of the dam. The ultimate bearing capacity of the dam would decrease obviously if the water pressure within cracks is considered. This study reveals that the coupling analysis model is a very effective tool for simulating the hydraulic fracturing in concrete structures. [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]

Abstract: The catalytic oxidation of volatile organic compounds (VOCs: ethanol, 1-propanol and 2-propanol) over Ag/Al2O3 catalyst under low and normal atmospheric pressure conditions has been studied with synchrotron vacuum ultraviolet (VUV) photoionization mass spectrometry (PIMS). The partial oxidation intermediates of the VOCs under different pressures were identified by PIMS and their photoionization efficiency (PIE) spectra. Alkene is preferentially formed under the low pressure conditions, while aldehyde and acid are favored under the normal atmospheric pressure conditions. In addition, the low pressure conditions are more suitable for observing the active intermediates, such as ethenol, ketene and propenal. The results indicate that the pressure has a significant effect on the oxidation pathway of VOCs over Ag/Al2O3 catalyst. [Copyright &y& Elsevier]

Low-pressure premixed laminar n-heptane+propane/oxygenlnitrogen flames were investigated with tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam sampling mass spectrometry. Three flames with different mass percentage of propane in the fuel blends of 0%, 10%, and 20% were studied. The combustion intermediates were identified by comparing the measured IEs with those values in literatures. Mole fraction profiles of the main species were compared among the three flames. The experimental results provide detailed data in understanding the combustion of n-heptane and n-heptane/propane blends in engine. They are also helpful in establishing and verifying the kinetic models. [ABSTRACT FROM AUTHOR]

Laminar premixed stoichiometric methane/hydrogen/oxygen/argon flames were investigated with tun- able synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam sampling mass spectrometry techniques. The methane/hydrogen fuel blends with hydrogen volumetric fraction of 0, 20%, 40%, 60% and 80% were studied. All observed flame species, including stable intermediates and radicals in the flames, were detected by measuring photoionization mass spectra and photoionization efficiency (PIE) spectra. Mole fraction profiles of major species and intermediates were derived by scanning burner at some selected photon energies near ionization thresholds. The influence of hydrogen addition on mole fraction of major species and intermediates was analyzed. The results show that the major species mole fraction of CO1 CO2 and CH4 decreases with the increase of hydrogen fraction. The mole fraction of intermediates measured in this experiment decreases remarkably with the increase of hydrogen fraction. This would be due to the increase of H and OH radicals by hydrogen addition and the high diffusivity and activity of H radical promoting the chemical reaction. In addition, the increase of H/C ratio with the increase of hydrogen fraction also leads to the decrease of the mole fraction of carbon-related intermediates and contributes to the decrease of unburned and incomplete combustion products. [ABSTRACT FROM AUTHOR]

Abstract: A procedure combining tunable vacuum ultraviolet (VUV) single-photon ionization with reflectron time-of-flight mass spectrometer has been developed for analysis of individual components in 90# unblended gasoline. Synchrotron radiation used as the ionization source can provide wide energy range and high resolution. All components can be identified by the molecular weights from photoionization mass spectrometry near threshold ionization and the ionization energies from photoionization efficiency spectra. About ninety components are detected in this study, including paraffins, olefins, and aromatics. Quantitative analysis can be obtained by the integrated ion intensity combining with data of photoionization cross-section. It appears that the tunable VUV photoionization mass spectrometry is a complementary method to previous existing ones for the analysis of individual components in gasoline. It may also be useful in other analytical applications. [Copyright &y& Elsevier]