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We consider the mutation invariants of cluster algebras of rank 2. We characterize the mutation invariants of finite type. Two examples are provided for the affine type and we prove the non-existence of Laurent mutation invariants of non-affine type. As an application, a class of Diophantine equations encoded with cluster algebras are studied. [ABSTRACT FROM AUTHOR]

To address the solid waste challenges associated with coal gasification fine ash, this study conducted a low-temperature alkali fusion de-ashing treatment to transform coal gasification fine ash into mineral-carbon adsorbent. The preparation process was simplified without grinding, carbonization and high-temperature (500–800 °C) activation treatment. The results demonstrate a positive linear correlation between the ash removal rate of the samples (measured during the preparation process, i.e., low-temperature alkaline fusion treatment of coal gasification fine ash) and their maximum equilibrium adsorption capacity for methylene blue. For the samples with an ash removal rate of 95.71 %, which exhibit a maximum adsorption capacity of 161.36 mg/g for methylene blue. The adsorption behavior of methylene blue on mineral-carbon adsorbent was a monolayer adsorption on the surface of homogeneous medium, involving both physical and chemical adsorption. The main adsorb rate-controlling steps for the samples with ash removal rates of 27.91–59.33 % and 95.71 % were the intra particle diffusion process and the liquid film diffusion process, respectively. The adsorption mechanism of methylene blue on the surface of mineral-carbon adsorbent involved electrostatic attraction and hydrogen bonding. The aforementioned results demonstrated the potential of coal gasification fine ash as an adsorbent material, providing new options for promoting the resource utilization and high-value applications of coal gasification fine ash. [Display omitted] • CGFA-derived mineral-carbon adsorbent was prepared via low-temperature alkali fusion. • Adsorption capacity correlates to the ash removal rate of mineral-carbon adsorbent. • The adsorption mechanism involves electrostatic adsorption and hydrogen bonding. [ABSTRACT FROM AUTHOR]

Coal gasification fine ash (CGFA) is characterized by high yield, high carbon content, and difficult recovery. This results in waste of coal resources and serious environmental pollution. To address this issue, a novel green deashing process is proposed in this study to modify CGFA into deashed carbon (DAC) with a high calorific value and an ash content of less than 5% through a low-temperature alkaline fusion process. Compared with traditional alkaline fusion (which is carried out at 600–1000 °C), low-temperature alkaline fusion treatment can efficiently remove ash minerals in the temperature range of 300–450 °C, which is beneficial to the efficient recovery of residual carbon in DA, while simultaneously improving the physicochemical properties and energy characteristics of DAC, thereby improving its combustion performance. At an alkali fusion temperature of 350 °C, a NaOH:DA ratio of 4.5:1, and a reaction time of 40 min, the resulting DAC product had ash content of 2.28%, combustible material recovery (CMR) of 82.03%, higher heating value (HHV) of 31.07 MJ kg−1, and S BET of 445.43 m2 g−1. In comparison, it was found that low-temperature alkali fusion significantly improved the deashing of CGFA when compared to existing deashing technologies. These results strongly suggest that this innovative deashing method can modify CGFA into a high-calorific value and low-N and S fuel, thereby providing a cost-effective and sustainable utilization method for CGFA. [Display omitted] • Low-temperature alkaline fusion can achieve green and efficient deashing of CGFA. • The combustible recovery rate of DAC is up to 82.03% and the ash content is 2.28%. • CGFA can be modified into high-calorific value and low-N and S content fuel. • Low-temperature alkali fusion is beneficial to the sustainable treatment of CGFA. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is an important cardiovascular disease that causes a great burden of disease. However, there is limited evidence of a link between air pollution exposure and AF. This study aimed to explore the short-term association between air pollution and AF. We obtained daily hospitalization of AF in two major hospitals of Yancheng, China from May, 2015 to May, 2020. Generalized additive models with quasi-Poisson regression were used to assess the associations between six criteria air pollutants and AF hospitalization. We explored the lag patterns, and visualized the concentration-response relationships. The robustness of the association was tested by two-pollutant model, and we explored potential effect modification by age, sex and season. A total of 15,171 inpatients from two hospitals were collected in this study with an average daily count of eight patients. We observed consistent and significant associations between six air pollutants and AF on lag 0–4 days. A 10 ug/m3 increase in PM 2.5 was associated with 2.81% (95%CI: 1.44%, 4.20%) changes in AF, and the effect estimate was 1.67% (95%CI: 0.77%, 2.59%) for PM 10 , 4.90% (95%CI: 1.69%, 8.22%) for NO 2 , 6.81% (95%CI: 0.46%, 13.57%) for SO 2 , 1.82% (95%CI: 0.60%, 3.06%) for O 3 ; a 0.1 mg/m3 increase in CO was associated with 2.55% (95%CI: 0.91%, 4.21%) increments in AF. Associations of PM 2.5 and PM 10 were robust after adjusting for SO 2 , NO 2 , CO, and O 3 , but not vice versa. Female patients and those aged less 70 years had larger risk of AF associated with air pollution exposure. The concentration-response curves of the six pollutants were almost linear and increasing with no obvious thresholds. This time-series study in Yancheng demonstrated increased risk of AF and a delayed effect over lag 0–4 days. Our findings suggested need of prevention and protection against these environmental risk factors for AF in health departments. [Display omitted] • Six air pollutants were associated with increased hospitalization for AF. • Longer lag patterns (lag 0-4d) were observed consistently for all air pollutants. • Females and patients less than 70 years were more susceptible. • Positive and increasing concentration-response relationships for air pollutants-AF. [ABSTRACT FROM AUTHOR]

• Thermal stability of 29 ionic liquids was assessed. • Fast (10 K/min) and slow (2 K/min) dynamic decomposition was investigated, as well as isothermal decomposition rates. • Isothermal decomposition rates for ILs under inert (N 2) versus oxidative (air) gaseous environments at different temperatures were compared. • Activation energies and vaporization enthalpies were calculated based on a zero-order kinetic model. • Decomposition mechanisms were analyzed for a selection of imidazolium, pyridinium, and tetraalkylphosphonium ILs. Ionic liquids (ILs) are being developed and studied for a variety of high-temperature applications, including as solvents for separations (where thermal regeneration is used) and as heat transfer fluids. Dynamic decomposition information has been reported for numerous ILs in the literature at various ramp rates. Although this information is useful for assessing how different characteristics, such as cation substituent groups or choice of anion, affect the decomposition of the ILs, dynamic decomposition temperature may overestimate the thermal stability of these compounds. Isothermal decomposition data is necessary when developing ILs in order to truly evaluate their thermal stability for high-temperature applications. However, this information is lacking for many ILs. In this study, we provide both fast (10 K/min) and slow (2 K/min) dynamic decomposition data, as well as isothermal decomposition data at five temperatures from 513.15 to 593.15 K for a selection of seventeen imidazolium, pyridinium, and tetraalkylammonium ILs and from 373.15 to 473.15 K for eight tetraalkylphosphonium ILs. There is significant mass loss after 16 h for most ILs even at 100 K below the decomposition temperature determined from dynamic measurements. Most ILs with the bis(trifluoromethylsulfonyl)imide anion ([Tf 2 N]−) show zero order mass loss, indicating that the mass loss is actually by evaporation rather than decomposition. Aminopyridinium ILs with [Tf 2 N]− are particularly thermally stable. We also compare isothermal decomposition rates for ILs under inert (N 2) versus oxidative (air) gaseous environments. The mass loss activation energies are lower in air, suggesting more decomposition (vs. evaporation) in air. Mass spectrometry confirms that nucleophilic substitution is the main decomposition mechanism for most ILs in N 2 , but β-elimination also occurs for the tetra-alkylphosphonium ILs. [ABSTRACT FROM AUTHOR]

[Display omitted] Due to the accumulation of heavy metal compounds produced by the sintering process in steel industry, the catalysts used for low-temperature selective catalytic reduction of NO with NH 3 (NH 3 -SCR) might be seriously deactivated. In this work, the deactivation effect of PbCl 2 , Pb(NO 3) 2 , and PbSO 4 on Mn-Ce activated carbon supported catalyst for low-temperature NH 3 -SCR of NO was investigated and compared. Poisoned catalysts were provided by impregnating fresh catalysts with Pb(NO 3) 2 , PbSO 4 and PbCl 2 aqueous solutions, respectively. Deactivation could be observed on the poisoned samples, and the deactivation degree was following PbCl 2 > PbSO 4 > Pb(NO 3) 2. The catalytic activities of all samples were tested, and the physicochemical properties of fresh and poisoned catalysts were assessed. PbCl 2 caused the most severe deactivation of the catalyst, owing to its poor redox property and surface acidity. Cl- could also react with Mn active sites to form -O-Mn-Cl bonds, resulting in additional acid sites, although these newly generated sites were not reactive in NH 3 -SCR reaction process. PbSO 4 exhibited moderate poisoning effect due to the addition of SO 4 2-, which created new Brønsted acid sites, facilitating the NH 3 adsorption and NO reduction. Pb(NO 3) 2 had the least poisoning impact on the catalyst due to the NO 3 –, promoting the NH 3 activation. The in situ DRIFTS results revealed that NH 3 -SCR reaction over all samples was governed by Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanism, and did not change due to the lead poisoning. Finally, a possible mechanistic model for different lead salts poisoning over Mn-Ce/AC catalyst was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] The key role played by the OH radical as a reactive intermediate motivates advanced methods for state-resolved OH detection. In this work, we take advantage of the wavelength- and bandwidth-tunable vacuum ultraviolet (VUV) pulses produced at the Dalian Coherent Light Source to modify a previously reported 1+1′ UV + VUV Resonance-Enhanced Multiphoton Ionization scheme [J. M. Beames, F. Liu, M. I. Lester, C. Murray, J. Chem. Phys. 134 , 241,102 (2011); J. M. Beames, F. Liu, M. I. Lester, Mol. Phys. 112 , 897 (2014)], in which OH in its ground X 2 Π electronic state is first excited to the A 2 Σ + state at around 281 nm, and subsequently ionized by 118 nm VUV radiation via the autoionizing ( A 3 Π , 3 d) Rydberg state. By tuning the VUV-free electron laser so that its bandwidth covers the entire A3 Π (v + = 0, 3d) ← A2 Σ + (v ″ = 1) band, we obtain enhanced sensitivity and accurate relative intensities for quantitative determination of quantum state distributions. The relative line intensities observed in the experiment agree with the simulated absorption intensities to within an error of <1% of the integrated band intensity. The 1+1′ scheme is also compared to a convenient one-color 2+1 scheme [M. Collard, P. Kerwin, A. Hodgson, Chem. Phys. Lett. 179 , 422–428 (1991)], which suffers due to rapid predissociation of the D 2Σ− state used as resonant intermediate. [ABSTRACT FROM AUTHOR]