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The thermodynamic properties of boron nitride under extreme pressures and temperatures are of great interest and importance for materials science and inertial confinement fusion physics, but they are poorly understood owing to the challenges of performing experiments and realizing ab initio calculations. Here, we report the first shock Hugoniot data on hexagonal boron nitride at pressures of 5–16 Mbar, using hohlraum-driven shock waves at the SGIII-p laser facility in China. Our density functional theory molecular dynamics calculations closely match experimental data, validating the equations of state for modeling the shock response of boron nitride and filling a crucial gap in the knowledge of boron nitride properties in the region of multi-Mbar pressures and eV temperatures. The results presented here provide fundamental insights into boron nitride under the extreme conditions relevant to inertial confinement fusion, hydrogen–boron fusion, and high-energy-density physics. [ABSTRACT FROM AUTHOR]

Compressed leachate is a contaminated liquid containing various organic and inorganic pollutants produced in municipal refuse transfer stations, which pollute soil and groundwater, posing serious risks to the environment and human health. The Environmental Technology Co., Ltd. (Shenzhen, Guangdong Province, South China) treated compressed leachate obtained from a refuse transfer station. The chemical oxygen demand (COD) (641.2 mg/L) of treated compressed leachate did not meet the wastewater quality standards in China for discharge into municipal sewers (COD ≤ 500 mg/L) and the company's design discharge requirements (COD ≤ 400 mg/L). Therefore, their further in-depth treatment is necessary. To this end, waste tobacco leaves were used as the biotemplate herein, and Fe/La-co-doped TiO2 (xFe,yLa)-TTiO2(g) was synthesized using a solvothermal-assisted biotemplating method. The photocatalytic depth treatment of compressed leachate was performed under simulated solar light using the prepared catalysts. After (3Fe,3La)-TTiO2(g) treatment, the COD of the leachate decreased from 641.2 to 280.1 mg/L, and the COD removal rate was 1.2, 1.1, and 1.6 times higher than that of pure Fe-doped, La-doped and non-biological template TiO2, respectively. Characterization confirmed that the biological template endowed the catalyst with a unique morphology and high specific surface area. Its rich activity sites are conducive to enhancing the adsorption capacity of pollutants and providing an ideal place for photocatalytic reactions. Co-doping with iron and lanthanum ions altered the band structure of TiO2 and promoted the interconversion of Fe3+/Fe2+ and La3+/La2+ during photocatalysis. First-principles density functional theory simulations demonstrated that co-doping Fe and La in TiO2 created impurity levels that facilitated the transfer of photogenerated electrons. This study provides a new purification pathway for the depth treatment of compressed leachate. [ABSTRACT FROM AUTHOR]

The wheat scab caused by Fusarium graminearum (F. graminearum) has seriously affected the yield and quality of wheat in China. In this study, gallic acid (GA), a natural polyphenol, was used to synthesize three azole-modified gallic acid derivatives (AGAs1–3). The antifungal activity of GA and its derivatives against F. graminearum was studied through mycelial growth rate experiments and field efficacy experiments. The results of the mycelial growth rate test showed that the EC50 of AGAs–2 was 0.49 mg/mL, and that of AGAs–3 was 0.42 mg/mL. The biological activity of AGAs–3 on F. graminearum is significantly better than that of GA. The results of field efficacy tests showed that AGAs–2 and AGAs–3 significantly reduced the incidence rate and disease index of wheat scab, and the control effect reached 68.86% and 72.11%, respectively. In addition, preliminary investigation was performed on the possible interaction between AGAs–3 and F. graminearum using density functional theory (DFT). These results indicate that compound AGAs–3, because of its characteristic of imidazolium salts, has potential for use as a green and environmentally friendly plant-derived antifungal agent for plant pathogenic fungi. [ABSTRACT FROM AUTHOR]

Myxobacteria are special bacteria with wide adaptability, which are rich sources of structurally diverse natural products with intriguing biological properties. Here, a gram-negative myxobacterium strain s54d21T was isolated from the sediment of a wetland park in China using the Escherichia coli baiting method. Based on 16S rRNA gene sequence and genomic data, the strain was demonstrated to be a novel species of a rare genus Hyalangium, designated Hyalangium ruber sp. nov (type strain s54d21T = GDMCC 1.1945T = JCM 39263T). The subsequent chemical investigation of the strain s54d21T led to the isolation of three rare 3,5,6-trisubstituted 2(1H)-pyrazinones, namely, hyalanones A-C (1-3), together with a known macrolactin A (4). Those new structures and their absolute configurations were unambiguously assigned by extensive analyses of spectroscopic data and density functional theory (DFT) calculations. In biological assays, compound 4 exhibited moderate cytotoxic activities against human cell lines RKO, A549, and NCM460 with IC50 values ranging from 27.21 to 32.14 µM. [ABSTRACT FROM AUTHOR]

In China, most of the high-sulfur iron ores have not been fully developed and utilized due to the lack of breakthrough progress in the research on the sulfur migration and the desulfurization mechanism during the roasting process. This study will focus on revealing the release and fixation mechanisms of sulfur during the roasting process to achieve the transformation of desulfurization from terminal treatment to process control. Experimental results show that as the roasting temperature increases, the release rate of SO2 also increases, reaching the maximum release rate at 900 °C. Simultaneously, it is found that at the same roasting temperature, the release rate and amount of SO2 under the O2/N2 atmosphere is significantly greater than that under the pure N2 and air atmospheres. Meanwhile, X-ray diffraction (XRD) is utilized to explore the phase composition of the roasted product and the sulfur release mechanism. In addition, the adsorption energy, stability and electron transfer of SO2 on the CaO surface are calculated through density functional theory (DFT), and the optimal adsorption active site perpendicular to the O atom (O-top) is also determined. Finally, the sulfur fixing agent CaO is used to study the SO2 fixation mechanism. When the concentration reaches 10%, the sulfur fixation efficiency reaches more than 80%. Therefore, this work will present basic knowledge and systematic guidance for the sulfur migration and release of high-sulfur iron ore under the oxidizing roasting process. [ABSTRACT FROM AUTHOR]

Red mud is a red-coloured, mud-like solid waste discharged from the industrial aluminium production process, which has a high output and is a pollutant. It exhibits a small particle size and a large specific surface area and contains active oxides. In this study, "red mud" and "phosphate" were used as keywords to retrieve research hotspots and progress for the red mud as a phosphate adsorbent in the past 10 y. CiteSpace and VOSviewer visual literature analysis software were used to cluster countries, institutions, authors, and keywords. Related patents showed that research on the phosphate adsorption performance of red mud has considerably increased since 2013 and that China has made a significant contribution. This paper summarises the main chemical composition and modification methods of red mud and collects from literature the relevant mechanism research and data on phosphate adsorption/desorption using red mud as an adsorbent. Summarising data on the microstructure of red mud adsorbent, it is found that there are few reports on red mud as adsorbent based on density functional theory. This study suggests that the problem of the steric hindrance of the red mud adsorbent in the phosphate adsorption process needs further research. [ABSTRACT FROM AUTHOR]

Artemisia divaricate belongs to the Artemisia genus of the family of Compositae, a sort of perennial herb endemic in most regions of China. For the first time, a phytochemical investigation was carried out on the whole plant of Artemisia divaricate, resulting in the identification of 39 sesquiterpenes, with 9 of them being new (1–9). The structures of the new compounds were fully established using extensive analysis of MS and 1D and 2D NMR spectroscopic data and density functional theory (DFT) NMR calculations. Their structures involve germacrane, eudesmane, and bisabolane types. All the new isolates were evaluated for their anti-inflammatory activities in lipopolysaccharide (LPS)-stimulated murine macrophages of RAW 264.7 cells. Compounds 2 and 8 showed a significant inhibition effect on NO production, with IC50 values of 5.35 ± 0.75 and 7.68 ± 0.54 µM, respectively. [ABSTRACT FROM AUTHOR]

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Iron Chlorin e6 (ICE6), a star plant growth regulator (PGR) with independent intellectual property rights in China, has demonstrated its efficacy through numerous field experiments. We innovatively employed salting-out assisted liquid-liquid extraction (SALLE) with HPLC-UV/Vis to detect ICE6 residues in water, soil, garlic seeds, and sprouts. Using methanol and a C18 column with acetonitrile: 0.1% phosphoric acid mobile phase (55:45, v:v), we achieved a low LOQ of 0.43 to 0.77 μg kg−1. Calibration curves showed strong linearity (R2 > 0.992) within 0.01 to 5.00 mg kg−1. Inter-day and intra-day recoveries (0.05 to 0.50 mg kg−1) demonstrated high sensitivity and accuracy (recoveries: 75.36% to 107.86%; RSD: 1.03% to 8.78%). Additionally, density functional theory (DFT) analysis aligned UV/Vis spectra and indicated ICE6's first-order degradation (2.03 to 4.94 days) under various environmental conditions, mainly driven by abiotic degradation. This study enhances understanding of ICE6's environmental behavior, aids in risk assessment, and guides responsible use in agroecosystems. [Display omitted] • HPLC- UV/Vis coupled to DFT is proposed for PGRs authentication. • Anabiotic degradation was predominant in the degradation of ICE6. • Hydrolysis followed the first-order kinetics. • Increasing the temperature will accelerate hydrolysis. • The validated method was subjected to actual samples. [ABSTRACT FROM AUTHOR]

[Display omitted] The rapid development of nuclear energy and the accelerated consumption of uranium (U(VI)) ores have forced researchers to turn to marine U(VI) harvesting. However, the performance of marine U(VI) harvesting materials was challenged by the combination of ultralow concentrations of U(VI), high concentrations of various interfering ions and biofouling from abundant marine living organisms. Natural abundant hemp fibers (HFs) were adhered by mussel-inspired polydopamine microspheres (HFMPDA) during self-polymerization. Both HFs and PDA are derived from natural products with low-cost and eco-friendly properties to guarantee compatibility with biological marine environments. HFMPDA exhibits an outstanding distribution coefficient of 10.51 ± 0.51 L g−1 for U(VI) and great fouling resistance. The coordination forms between the U(VI) ion and HFMPDA were investigated by density functional theory (DFT), and the antifouling property was simulated by molecular dynamics (MD) calculations. The adsorption capacity of HFMPDA is 128.43 ± 3.26 μg g−1, which is 1.75 and 6.05 times higher than that of HFPDA (only covered by PDA) and V(V), respectively, after immersion for 34 days in the Yellow Sea, China. These polydopamine microspheres adhered to HF will be a photothermal marine U(VI) harvesting material with enhanced selectivity and fouling resistance. [ABSTRACT FROM AUTHOR]

Owing to containing high fraction of organic matter, the tannery sludge seemed to be fit for composting. Actually, it was intensively harmful to the environment, due to containing chromium (Cr). So it might undergo a long time of storage until finding a proper way to dispose it. In the storage period, it would expose the surrounding environment a risk via releasing Cr. In this study, an approach was proposed to minimize the amount of released Cr, and reveal the mechanism on immobilizing Cr. Collagen protein waste (CPW) was adopted to immobilize Cr, and it was evaluated via leaching experiment. The lowest leaching concentration of Cr was 12 mg/L, meeting the limits of related standard in China (GB 5085.3–2007, Tcr < 15 mg/L). Moreover, the compositions and functional groups of the optimum sample (12 mg/L) were also characterized, confirming that the dominant functional groups cross-linking with Cr were hydroxyl (-OH), carboxyl (-COOH), and epoxy (-COC). Importantly, density functional theory (DFT) calculation was also employed, suggesting that Cr was restrained by accepting electrons from O atoms donating by functional groups. [ABSTRACT FROM AUTHOR]

[Display omitted] • A resource utilization approach of field AMD for the formation of LDHs was proposed. • LDHs derived from field AMD possesses a larger removal capacity for Sb compared with other LDHs from chemical reagents. • Sb(V) removal by LDHs was attributed to anion exchange and formation of brandholzite. • The removal mechanism of Sb by LDHs was revealed by DFT calculations. Although acid mine drainage (AMD) has been recognized as a major environmental pollutant, it is also a potential source of valuable metals and sulfate. In this study, a resource utilization approach of field AMD for the formation of iron-based layered double hydroxides (LDHs) with sulfate intercalation was proposed and its capacity for removing antimonate [Sb(V)] was examined. Layered double hydroxides derived from field AMD possesses a more rapid equilibration time (<120 min) and a larger removal capacity (78 mg g−1) for Sb(V) compared with other LDHs from chemical reagents. Following the treatment of field AMD containing 10.7 mg L−1 Sb, a residual Sb concentration of 4.0 μg L−1 was achieved using a dose of 1 g L−1 LDHs, which meets the drinking water standard of 5 μg L−1 recommended by China's Ministry of Health. Leaching tests showed negligible metal(loid)s dissolution in Sb-loaded LDHs over a short period. The interactions between Sb(V) and LDHs include anion exchange and formation of brandholzite, which were further investigated at the electronic scale using density functional theory (DFT) calculations. It is envisaged that this approach for preparing LDHs will provide theoretical support for the remediation and resource recovery of AMD. [ABSTRACT FROM AUTHOR]

Monolayer transition metal dichalcogenides can normally exist in several structural polymorphs with distinct electrical, optical, and catalytic properties. Effective control of the relative stability and transformation of different phases in these materials is thus of critical importance for applications. Using density functional theory calculations, we investigate the effects of low-work-function metal substrates including Ti, Zr, and Hf on the structural, electronic, and catalytic properties of monolayer MoS2 and WS2. The results indicate that such substrates not only convert the energetically stable structure from the 1H phase to the 1T′/1T phase, but also significantly reduce the kinetic barriers of the phase transformation. Furthermore, our calculations also indicate that the 1T′ phase of MoS2 with Zr or Hf substrate is a potential catalyst for the hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

Steam reforming (SR) is a process for converting transportation fuels into hydrogen-rich gas, which can be fed to SOFCs for on-board power supplies. Herein, we prepare Mg x Ni 1-x O (0.5

Molecular networking strategy-based prioritization of the isolation of the rarely studied soft coral Sinularia tumulosa yielded 14 sesquiterpenes. These isolated constituents consisted of nine different types of carbon frameworks, namely asteriscane, humulane, capillosane, seco-asteriscane, guaiane, dumortane, cadinane, farnesane, and benzofarnesane. Among them, situmulosaols A-C (1, 3 and 4) were previously undescribed ones, whose structures with absolute configurations were established by the combination of extensive spectral data analyses, quantum mechanical-nuclear magnetic resonance and time-dependent density functional theory electronic circular dichroism calculations, the Snatzke's method, and the modified Mosher's method. Notably, situmulosaol C (4) was the second member of capillosane-type sesquiterpenes. The plausible biogenetic relationships of these skeletally different sesquiterpenes were proposed. All sesquiterpenoids were evaluated for their antibacterial, cytotoxic and anti-inflammatory effects. The bioassay results showed compound 14 exhibited significant antibacterial activities against a variety of fish and human pathogenic bacteria with MIC 90 values ranging from 3.6 to 33.8 μg/mL. Moreover, moderate cytotoxic effects against HEL cells for components 13 and 14 and moderate inhibitory effect on lipopolysaccharide-induced inflammatory responses in RAW264.7 cells for substance 13 were also observed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Yttrium (Y) is a crucial rare earth element, and it is found in the ion-adsorption rare earth ore of Jiangxi province, China, at a percentage of up to 64.9%. This study used density functional theory calculations to investigate the adsorption behaviour and bonding mechanisms of the Y ion on the surface of kaolinite (001). Understanding these would be beneficial for its mineralisation processing and exploitation. [Y(OH) 2 (H 2 O) 7 + was studied as the initial adsorption structure with the lowest binding energy of −1629.19 kJ/mol in an aqueous system. The adsorption models were divided into outer-layer and inner-layer adsorption models based on the adsorption energy and bonding mechanisms. It was found that [Y(OH) 2 (H 2 O) 7 + preferred to adsorb on the Al-OH surface with inner-layer adsorption mainly via the coordination bond of Y–O s , and through hydrogen bonds for outer-layer adsorption. In the outer-layer adsorption, the adsorption energy of [Y(OH) 2 (H 2 O) 7 + on the Al-OH surface was higher than that on the Si–O surface because of the steric hindrance effect of the H in the hydroxyl of the Al-OH surface. The Mulliken bond populations of Y–O s for inner-layer adsorption showed that it was primarily dominated by the bonding orbital. [Display omitted] • The adsorption of hydrated Y3+ on kaolinite surface have been investigated with DFT. • Hydrated [Y(OH) 2 + tend to coordinate with more H 2 O ligands until 7 in aqueous. • The outer-layer adsorption of hydrated [Y(OH) 2 + were related to hydrogen bonds. • Hydrated [Y(OH) 2 + prefer to adsorb on Al-OH surface with inner-layer adsorption. [ABSTRACT FROM AUTHOR]

Dolomite is an important industrial raw material for the production of metal magnesium. However, the calcination of dolomite is a typical pollution-intensive industry and is one of the major contributors to CO 2 emissions in China. The requirements of energy conservation and environmental protection are driving the development of new calcination technologies. Herein, we developed a rapid and environment-friendly strategy for the calcination of dolomite used in subsequent magnesium production through carbothermal reduction, in which the pellets containing dolomite and carbon additive are calcined with in-situ Joule-heating in a vacuum. The effect of input volumetric specific power, heating time, vacuum conditions, carbon additive, and the size of the pellets on the decomposition process has been systematically studied. The dolomite in the pellets can be completely decomposed within tens of seconds. And the kinetic analysis shows that the activation energy of the decomposition of dolomite with the Joule-heating method is 108.4 kJ mol−1, which is much lower than the previous reports. Note that, the novel strategy shows a reduction of calcination time by 70 times, a reduction of energy consumption by 6.22% and a reduction of direct carbon emissions by 56.77% compared to the traditional methods. Combining the results of finite element simulations and density functional theory calculations, we revealed the mechanism of Joule-heating to enhance the decomposition of dolomite. The results show that the Joule-heating method can offer a distinct heating mechanism and deteriorate the structure stability of CaMg(CO 3) 2. • A rapid and environment-friendly method for the calcination of dolomite. • Dolomite can be completely decomposed in tens of seconds with Joule-heating. • Joule-heating can significantly reduce energy consumption and carbon emissions. • The mechanism of Joule-heating to enhance the decomposition of dolomite is analyzed. [ABSTRACT FROM AUTHOR]

Single-atom catalysis is a new field that has developed rapidly in recent years and has greatly helped the development of catalytic science. We have processed a large amount of literature data through the Web of Science database. The bibliometric method was used to analyze the development trend and research hotspots over the past 10 years since the concept of single-atom catalysis was proposed in 2011. Results show that the field of single-atom catalysis is currently at a high-speed development stage. China is in a leading position in terms of comprehensive strength, with the largest number of publications and great influence. Most productive journals and institutions are ACS Catalysis and Chinese Acad. Sci. Single-atom catalysis has the most research results in the field of chemistry. In addition, the most commonly used keywords are "density functional theory", "oxygen reduction reaction", "electrocatalysis", "co oxidation", "graphene", "heterogeneous catalysis", "platinum", "hydrogen evolution reaction", which reflect the research direction of the current field. This article reviews the main research content of single-atom catalysts in order to facilitate researchers understanding the current situation in the field, and to also provide some guidance for future research. [ABSTRACT FROM AUTHOR]

This paper aims to reveal the formation process of pitchblende by analyzing its microstructural features on the nanoscale and atomic scale. Herein, we selected pitchblende samples from drilling cores from the Miaoershan area, southern China, as the research objects. The microstructural features of pitchblende particle cores were analyzed using high-resolution transmission electron microscopy (HRTEM), electron diffraction, energy spectrum (EDS) and electron microprobe analysis (EMPA), combined with density functional theory calculations. The results of this study reveal that the pitchblende grain boundaries are not clear, as they exhibit a cloudy distribution and some preferred orientations under HRTEM. The selected area electron diffraction (SAED) analyses show discontinuous ring patterns that are coherent with the presence of a preferred orientation. The HRTEM results reveal that pitchblende is a complex aggregate composed of nanocrystals with a diameter of 3–7 nm and unit cell parameters of a0 = 0.556 nm. The elements in the pitchblende are characterized by an irregular and scattered distribution of Ca, As, S, Fe, Mn, and Si. We assume that the formation of pitchblende is related to hard-base fluid in a reduced environment containing As and S. We used density functional theory calculations to obtain the pitchblende crystal structure model and simulated the positions of the U and O atoms to provide a reference for further analysis of the pitchblende crystal structure. We conjecture that uranium ions of U4+, U5+ and U6+ may coexist in pitchblende (stoichiometry U3O7). [ABSTRACT FROM AUTHOR]

At present, coal is still the main source of energy supply in China. However, However, coal dust, due to spontaneous combustion or gas explosion, seriously affects underground safety production and also threatens the occupational health of underground workers. To understand the causes of harm caused by coal from the perspective of its oxidative pyrolysis characteristics, bituminous coal was selected as the experimental coal sample, To further understand the oxidation pyrolysis characteristics of bituminous coal, thermal analysis and density functional theory were applied. By using industrial analysis, particle size analyzer, SEM and FTIR to characterize the experimental bituminous coal. The multi heating rate experiment of bituminous coal was carried out with thermogravimetric analyzer, and the kinetic analysis results displayed the apparent activation energy of oxidation pyrolysis of bituminous coal ranges from 118.57 to 124.96 kJ mol−1. The TG-FTIR experiments found the main gaseous products of the oxidation pyrolysis of bituminous coal were CO and CO 2. The surface electrostatic potential and bond dissociation energy of bituminous coal structure were analyzed by density functional theory. The research results provide important preliminary references for the safe mining of coal mines and the industrial application of bituminous coal. [Display omitted] • TG tests were used to investigate thermal stability and kinetics of bituminous coal. • Gaseous products of bituminous coal were analyzed by EGA technology. • Analyzing the basic characteristics of bituminous coal using characterization methods. • Analyzing bituminous coal bond breaking details through ESP and BDE methods. [ABSTRACT FROM AUTHOR]

As an effective conservation material for wall paintings, ancient paper, and stone artifacts, nano Ca(OH)2 has been studied for more than two decades. However, the synthesis methods are expensive, complex, time‐consuming, or require considerable energy. To tackle the issue, we report, in this study, a facile, large‐scale, time saving, and economical method for synthesizing nano Ca(OH)2 (∼90 nm) at room temperature. This is achieved by controlling crystal growth of Ca(OH)2 at the (1‾010) facet (vertical direction) and (0001) facet (horizontal direction) with simultaneous addition of octyl phenyl polyoxyethylene ether (OPPE) and dimethylformamide (DMF) in the reaction. Density functional theory (DFT) calculations revealed that the crystal dimensionality tuning is caused by attaching OPPE to the (0001) facet and DMF to the (1‾010) facet of Ca(OH)2. Experimental results showed that the synthesized nano Ca(OH)2 has higher stability and carbonation degree than commercial Ca(OH)2 and was used for consolidating a 1300‐year‐old tomb painting, which is a very important, precious, and heavily damaged national treasure of China. The results demonstrate that the nano Ca(OH)2 shows excellent penetration into the painting, considerably improves the strength of the painting, and has no side effects on the color, pore distribution, and porosity of the painting. Our work will significantly facilitate the industrial production of nano Ca(OH)2 and its application in cultural heritage conservation. [ABSTRACT FROM AUTHOR]

Collectors play a decisive role in froth flotation by selectively hydrophobizing mineral particles. The new understanding of the molecular design of collectors, their flotation mechanism and green manufacture is reviewed in this paper. The density functional theory (DFT) calculation opens a new avenue for understanding the reactivity of the groups and atoms in a collector molecule, and azolethione surfactants including oxadiazolethione, thiadiazolethione, triazolethione, amino-triazolethione and tetrazolethione, have been designed and developed as collectors. The combination application of the DFT calculation and in situ detection technologies establishes a new platform for flotation fundamental research, and the monomolecular layer of a sulfhydryl collector chemisorbed on chalcopyrite has been observed and measured, and the nature of froth flotation is further understood. The new synthetic technologies for collectors such as xanthates and hydroxamates have been developed to prepare them in near atom economy, which supported their green manufacture and industrial upgrading. The new understanding of flotation collectors will boost their future development. [ABSTRACT FROM AUTHOR]

The pores in shales are mainly of nanometer-scale, and their pore size distribution is very important for the preservation and exploitation of shale gas. This study focused on the organic-rich Lower Silurian black shale from four wells in the Upper Yangtze Platform, and their TOC, mineralogical composition and pore characterization were investigated. Low pressure N2 and CO2 adsorption were conducted at 77.35 K and 273.15 K, respectively, and the pore structures were characterized by modified Brunauer-Emmett-Teller (BET), Dubinin-Radushkevich (DR), t-plot, Barrett-Joyner-Halenda (BJH) and density functional theory (DFT) methods and then the relationship between pore structure and shale gas sorption capacity was discussed. The results indicate that (1) The Lower Silurian shale has high TOC content of 0.92%-4.96%, high quartz content of 30.6%-69.5%, and high clays content of 24.1%-51.2%. The total specific surface area varies from 7.56 m2/g to 25.86 m2/g. Both the total specific surface area and quartz content are positively associated with the TOC content. (2) Shale samples with higher TOC content have more micropores, which results in more complex nanopore structure. Micropore volumes/surface areas and non-micropore surface areas all increase with the increasing TOC content. (3) A combination of N2 and CO2 adsorption provides the most suitable detection range (∼0.3-60 nm) and has high reliability and accuracy for nanopore structure characterization. (4) The TOC content is the key factor to control the gas sorption capacity of the Lower Silurian shale in the Upper Yangtze Platform. [ABSTRACT FROM AUTHOR]

High moisture content greatly restricts the large-scale utilization of low-rank coals (LRCs). Hydrothermal dewatering (HTD) is a promising technique for dewatering and upgrading LRCs. Chinese lignite from XiMeng Mine in Inner Mongolia was upgraded by HTD. The effects of pore structure and oxygen functional group content on moisture distribution were investigated. Thermogravimetric analysis, mercury intrusion porosimetry, and chemical titration were conducted to characterize the physicochemical properties of coal samples. Results show that a substantial amount of moisture was removed, the coal composition was modified, and the energy density was significantly improved after HTD. Both free-phase and bound-phase moisture in lignite were significantly removed. Free water removal was associated with the collapse of macropore structures caused by shrinkage forces. The bound water was remarkably reduced as a result of the removal of oxygen functional groups, such as phenolic hydroxyl and carboxyl. During HTD, the oxygen functional groups were decomposed, and the hydrogen bonding between water and hydrophilic sites was destroyed, thereby leading to a weakening of the water-holding capacity of lignite. Four representative model molecules with different polarities were used to study the intermolecular interactions between lignite and water. The interaction energies of model molecule⋯water complexes were determined by density functional theory (DFT) calculation. The types of non-covalent interactions of both hydrophobic and hydrophilic sites in lignite with water were vividly demonstrated using color-mapped reduced density gradient isosurface. The carboxyl and hydroxyl groups are extremely liable to interact with water via hydrogen bonding with large interaction energy and exhibiting strong hydrophilicity. On the other hand, the alkanes and benzene rings interact with water via van der Waals attractions and show hydrophobic effects. [ABSTRACT FROM AUTHOR]

Hydrogen produced by electrochemical water splitting depends on the development of highly efficient electrocatalysts. In this study, we report the design and synthesis of a robust hydrogen evolution reaction (HER) electrocatalyst Mo 2 C-Ru@CNBs, which is consisted of heterostructured Mo 2 C-Ru nanoparticles that dispersed on three-dimensional interconnected carbon nanobelts (CNBs). Benefiting from the high intrinsic catalytic activity of Mo 2 C-Ru heterostructure, abundant catalytic active sites and facilitated mass transfer, the Mo 2 C-Ru@CNBs catalyst shows high HER catalytic activity with ultralow overpotentials of 17 and 18 mV at 10 mA cm−2 in acidic and alkaline media, respectively, which are superior to the individual components of Mo 2 C@CNBs and Ru@CNBs catalysts, commercial 20% Pt/C and the recently reported Mo- and Ru-based electrocatalysts. Density functional theory calculations reveal the extensive electronic interaction between Mo 2 C and Ru at the heterointerfaces, leading to well-modulated electronic structure for optimized intrinsic catalytic activity and enhanced electrical conductivity. [Display omitted] In Chinese mythology, the belt-like Chaotic Silk was a magic weapon of Nezha and he defected the fierce dragon with Chaotic Silk in the east China sea. In this TOC image, the Chaotic Silk represents the robust belt-like nanostructured catalyst Mo 2 C-Ru@CNBs and the dragon represents the reaction barriers of HER. We aim to create a vivid visualization image to reveal the high catalytic activity of Mo 2 C-Ru@CNBs for efficient HER electrocatalysis. [ABSTRACT FROM AUTHOR]

To address the drinking safety problems associated with high arsenic(III) (As(III)) and bacteria in underground water, core-shell Fe–Ag@AgCl nanowires were synthesized and exhibited excellent photocatalytic oxidation effects on co-existing As(III) and Escherichia coli (E. coli). With the introduction of Fe, the nanowires that were used 5 times could be easily magnetically collected, and the As(III) oxidation effect of these re-chlorinated nanowires increased from 39% to 60%. E. coli was completely inactivated within 60 min without photoreactivation after 20 min. Extracellular polymeric substances have play a protective role in the disinfection process. Quenching testing results confirmed that, except for the superoxide radical (•O 2 −), the subdominant active species were different for different objects: hole (h VB +) to As(III) and hydroxyl radical (•OH) to E. coli. Therefore the system with co-existing As(III) and E. coli , the inactivation effect of Fe–Ag@AgCl on E. coli decreased remarkably with an increase in As(III) concentration, while the oxidation process of As(III) was not significantly affected by E. coli until E. coli was increased to 108 cfu/mL. The photocatalytic process of co-existing As(III) and E. coli is displayed in a schematic diagram and was tested using desired results obtained from field groundwater in Xiantao City, Hubei Province. The function of Fe in band structures and density of states was analyzed using plane-wave density functional theory. These magnetic nanowires presented excellent photocatalytic ability on co-existing As(III) and E. coli , and provided new insights into drinking water safety in high-arsenic areas. [Display omitted] • Fe–Ag@AgCl exhibited excellent photocatalytic effect on As(III) and E. coli. • O 2 − was the dominant species in the Fe–Ag@AgCl photocatalytic system. • Fe–Ag@AgCl was attempted in groundwater in Xiantao City, Hubei Province, China. • Function of Fe was analyzed using plane-wave DFT and schematic diagram was drawn. [ABSTRACT FROM AUTHOR]

Influence of the surficial physiochemical properties on the adsorption and conversion of SO 2 on calcite {1 0 4}. [Display omitted] • The adsorption of SO 2 can be enhanced by both the surface defects and the adsorbed H 2 O on the calcite {1 0 4}. • Oxidation of SO 2 with O 3 is proposed to occur by an Eley-Rideal mechanism. • For Mn-doped calcite {1 0 4}, SO 2 can be converted to adsorbed SO 3 by O 3. The presence of H 2 O is adverse to the conversion of SO 2. • For CO 3 2– vacancy defected calcite {1 0 4}, with the aid of dissociated H 2 O, SO 2 can be easily converted into sulfate. The role of mineral dust on atmospheric pollutions formation is one of the significant challenges in environmental and atmospheric science. The conversion of atmospheric pollutions on mineral dust depends largely on its surface physiochemical properties. However, the adsorption and conversion of polluting gases on typical mineral dust surface in China are still poorly understood. In this study, the impact of calcite surface defects, oxidizers and adsorbed H 2 O on the adsorption and oxidation process of SO 2 on calcite {1 0 4} surface is systematically studied by density functional theory (DFT) method. The results indicate that the surface defects enhance the adsorption of SO 2 on calcite {1 0 4} surface. Compared with O 2 , O 3 is more beneficial for the oxidation conversion of SO 2 on various calcite {1 0 4} surfaces. For pristine calcite {1 0 4} and Mn-doped calcite {1 0 4}, SO 2 can be converted to adsorbed SO 3 by O 3 , while adsorbed H 2 O inhibits this process. For CO 3 2– vacancy defected calcite {1 0 4} surface, with the aid of dissociated H 2 O, SO 2 can be easily converted to sulfate instead of adsorbed gaseous SO 3. Thus, the evolution of the adsorbed SO 2 on calcite {1 0 4} can be regulated by the surface physiochemical properties and the adsorbed H 2 O. [ABSTRACT FROM AUTHOR]

Cu(II)-EDTA is a highly stable typical metal-organic complex in a wide pH range (3.0–12.0) and it is difficult to deeply purify Cu(II) by conventional precipitation methods. In this study, Fe(III) replacement/diethyldithiocarbamate (DDTC) precipitation combined process is proposed as a promising strategy to achieve the deep purification of Cu(II) from Cu(II)-EDTA acidic wastewater. The underlying mechanism has also been systematically elucidated by chemical equilibriums, experiments, and density functional theory (DFT) calculations, laying a foundation for the development and application. Chemical equilibriums show that Fe(III) replacement favors the stoichiometric release of Cu(II) from Cu(II)-EDTA and the formation of Fe(III)-EDTA complex under acidic conditions. Experimentally, Cu(II) is removed (over 99.99%) and deeply purified (under 0.008 mg/L) under the optimal conditions, which is lower than the most stringent discharge standards of copper ions in electroplating effluent (<0.5 mg/L, China). DFT calculations reveal that DDTC could further precipitate the released free copper ions via the carbon disulfide (–C(=S)–S) chelating group while exhibiting a slight effect on the Fe(III) in Fe(III)-EDTA. Considering these results, the electronic structures of Cu(II) and Fe(III), as well as their interaction with EDTA and DDTC ligands, are discussed to understand the mechanism of Fe(III)/DDTC process. By introducing a low dosage of Fe(III), the DDTC could efficiently purify Cu(II) from the Cu(II)-EDTA acid wastewater and realize the near-zero discharge of metal pollutants in metal-organic complex wastewater. It is believed that the main findings may benefit the water pollution reduction and comprehensive recycling of metal resources. [Display omitted] • Fe(III)/DDTC process is a promising strategy to treat Cu(II)-EDTA wastewater. • Fe(III) can effectively replace the Cu(II) from Cu(II)-EDTA complexes. • The released Cu(II) by Fe(III) replacement can be targetedly precipitated by DDTC. • The underlying mechanism is elucidated based on density functional theory calculations. [ABSTRACT FROM AUTHOR]

The disposal of the Cr containing tannery sludge has become a serious environmental problem in China, which has attracted increasing attention. However, experimental and theoretical research is still needed. We developed a feasible route to synergistic immobilization the Cr in tannery sludge into the spinel-based phases by addition of ZnO and TiO 2. ZnO and Cr3+ can form stable spinel-based phase, and TiO 2 can suppress the formation of Cr6+. The significantly synergistic effect between ZnO and TiO 2 promoted the immobilization of Cr in tannery sludge and reduce the leaching of the chromium in the annealed sludge. The oxidation of Cr3+ to Cr6+ in the presence of alkaline substances has been elucidated by density functional theory, and it is revealed that the electrons from the Cr-d orbit jump to the Ca-d and directly transform into the O 2. [Display omitted] • Chromium element is fixed in the spinel crystal lattice by loading of ZnO. • The Cr3+ oxidation process with the alkaline matter is retarded by ZnO and TiO 2. • The oxidation mechanism of Cr 2 O 3 with CaO is elucidated by computation. [ABSTRACT FROM AUTHOR]

Although there have been a lot of studies on the adsorption of trivalent actinides on clay minerals, the gaps between surface complexation model (SCM) for the description and prediction of macroscopic adsorption and the coordination structures and configurations of the surface complexes are still not completely bridged. Aiming at a multi-scale description of Am(III) adsorption on bentonite, density functional theory (DFT) calculations and surface complexation modeling were carried out. The results showed that the SCM considering cation exchange reactions and the formation of surface complexes, i.e., ≡SSOAm2+, ≡SSOAm(OH)+ and ≡SSOAm(OH) 2 could reproduce all batch experimental data for Am(III) adsorption on Gaomiaozi bentonite, a potential buffer material for China's Beishan high-level radioactive waste repository. The stoichiometric coefficients of 1 in the SCM are deduced, while the surface complexes at the sites of ≡Al(OH) 2 on (010) surface and those of ≡AlO(OH) on (110) surface are bidentate according to DFT calculations. The detailed calculations of electronic structures indicated that both covalent bond and electrostatic interaction account for Am(III) coordinating with the surface hydroxyl groups. In addition, it was found that the structures and energy properties of Am(III) complexes on (010) surface are similar to those on (110) surface. Hydrogen bonds between binding waters of Am(III) and the surface hydroxyl groups are formed in all cases, contributing to additional stability of Am(III) surface complexes. Overall, this study provides an improved understanding of Am(III) adsorption on the edge surfaces of bentonite/montmorillonite. [Display omitted] [ABSTRACT FROM AUTHOR]

The trends and mechanisms of organic carbon changes in coastal delta croplands are not yet clear due to the complexity physicochemical processes in soil. In this study, combing powder x-ray diffraction (XRD), microbial analysis, and density functional theory in quantum mechanics, we proposed a novel mechanism underlying OC accumulation. We investigated changes of three kinds of organic carbon (OC)-dissolved organic carbon (DOC), light fraction organic carbon (LFOC), and heavy fraction organic carbon (HFOC) in the Yellow River Delta croplands. We found that HFOC, dominant in coastal delta cropland soil, formed at different ages and its density increased with increasing reclamation time. Yet, DOC and LFOC had no significant increase or decrease tendency. Moreover, in coastal delta croplands, HFOC accumulation might be a complex progress, including the loss of indigenous OC and the accumulation of newly input OC. Based on these results, we proposed that although root exudative DOC (organic acids) could cause the indigenous OC loss by forming a specific microbial community, it still was a source of HFOC and promoted the OC accumulation. More importantly, based on density functional theory, we verified that these root exudative organic acids could adsorb on SiO 2 together with crystalline Fe oxides (Fe c ) to form aggregates. The finding could explain the phenomenon that the XRD results showed samples were compounds of SiO 2 , Fe c , and OC and the accumulation of HFOC in coastal delta croplands. By revealing a new OC accumulation mechanism in coastal delta croplands, this study provides novel insights into the mechanism of OC dynamics in coastal delta croplands and the global carbon budget., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Red soil, a typical soil type in southern China, has been deemed infertile or nutrient-deficient. In this study, red soil was firstly utilized as a substrate for preparing catalysts, which were then successfully applied to the catalytic wet peroxide oxidation (CWPO) of cephalexin. The highest cephalexin removal was 95.23% and TOC removal was 60.58%, with the catalyst pyrolyzed at 500 °C (RC500). The high iron content and proportion of Fe(II) on the surface of RC500 was responsible for the decomposition of H 2 O 2 into· OH. Moreover, the porous structure and existence of other minerals (such as SiO 2 and Al 2 O 3) in the catalyst were also significant for enhancing the catalytic activity of RC500. Afterwards, the influencing parameters, including temperature, pH, the dose of H 2 O 2 , and catalyst, were examined for cephalexin degradation. It was noteworthy that RC500 was efficient in treating hospital wastewater when using a self-design pilot device. A density functional theory analysis of cephalexin was conducted to establish the possible position attacked by ·OH, and the possibly ruptured one. Meanwhile, the intermediates generated during CWPO were identified. Finally, a reliable degradation pathway of cephalexin was proposed on the basis of the results. [Display omitted] • Red soil was first utilized in preparing efficient catalysts in CWPO. • Pyrolysis temperature affected iron dispersion on the surface of red soil carbons. • The cephalexin and TOC removals with RC500 were 95.23% and 60.58%, respectively. • The RC500 catalyst performed well in the treatment of hospital wastewater. • A density functional theory analysis was used for proposing degradation pathways. [ABSTRACT FROM AUTHOR]

The lacustrine shales (e.g. shales deposited in the lake) are important commercial production targets for the oil and gas industrial. The pore network of shales has a significant effect on the occurrence state of natural gas&oil and reserve calculation. The exploration practice has indicated that the pore network of lacustrine shale is very different from that of marine shale. Although many researches have proposed that the pore network of lacustrine shales is influenced by clay minerals, however, the origin, evolution and preservation of pores in the lacustrine shales are still obscure. This study aims to reveal the effect of synchronous hydrocarbon generation and smectite-illite conversion on the formation and evolution of pores in lacustrine shales from the Chang #7 (C7) Member of the Upper Triassic Yanchang Formation in Ordos Basin, China. The middle and lower part of C7 Member is known as the "Zhangjiatan" shale, which is focused by oil shale exploration recently in China. The combination of analytical techniques was used to investigate the pore evolution related to clay minerals. The clay minerals within shales from the C7 Member consist of illite-smectite mixed layer minerals, illite, kaolinite and chlorite, accounting for 25.9–59.1% of the whole rock. There is a positive relationship between density functional theory (DFT) pore volumes and the content of clay minerals. DFT method is appropriate for all types of the pore, especially micropores. The mesopores (2–50 nm) dominated in the shale samples, while the organic matter only hosted a small amount of micropores (<2 nm). In the study, it's shown that the development of mesopores is controlled by the smectite-illite conversion. The mesopores volume and surface areas will decrease with the smectite layers converting into illite. However, the marcopores (>50 nm) can increase with the formation of illite layers, caused by the minerals volume shrinks and overpressure. The smectite-to-illite conversion is favorable for the pore network under the moderate thermal maturity. The synchronous smectite-to-illite conversion and hydrocarbon generation is a critical mechanism for the formation and preservation of pores in the lacustrine shale. • The amount of marcopores increase with illitization. • The mesopores and surface areas will decrease with the smectite-to-illite conversion. • Smectite-to-illite conversion and hydrocarbon generation induce the pores evolution. [ABSTRACT FROM AUTHOR]

The biotransformation of organophosphate esters (OPEs) in white lupin ( Lupinus albus ) and wheat ( Triticum aestivum L.) was investigated in hydroponic experiments with different phosphorus (P)-containing conditions. The hydrolysis rates of OPEs followed the order of triphenyl phosphate (TPHP) > tri- n -butyl phosphate (TnBP) > tris(1,3-dichloro-2-propyl) phosphate (TDCPP). Hydrolysis of OPEs was accelerated at P-deficient conditions, and faster hydrolysis took place in white lupin than in wheat. Coincidingly, the production of acid phosphatase (ACP) in both plants was promoted, and much higher intracellular and extracellular ACPs were observed in white lupin under P-deficient conditions. In vitro experiments revealed that ACP was a key enzyme to hydrolyze OPEs. The hydrolysis rates of OPEs were significantly correlated with the Hirshfeld charges, calculated by density functional theory, of the oxygen atom in the single P-O bond. Using ultra-high-performance liquid chromatography coupled with Orbitrap Fusion mass spectrometer, 30 metabolites were successfully identified. Some of these metabolites, such as sulfate-conjugated products, hydration of cysteine-conjugated products of TPHP, and reductively dechlorinated metabolites of TDCPP, were observed for the first time in plants. It is noteworthy that OPEs may transform into many hydroxylated metabolites, and special attention should be paid to their potential environmental effects.

• Umifenovir physicochemical stability was studied. • DFT and analytical chemistry enabled to characterize the main degradation process. • 6 New degradation products were characterized by LC-HRMSn. Umifenovir is an antiviral drug approved in China and Russia for the treatment of influenza. The available dosage form consists of capsules marketed under the brand name Arbidol®. Due to its broad spectrum, umifenovir may also be used in other viral contexts, alone or combined with other antiviral drugs. Although knowledge of umifenovir intrinsic stability may be useful for any potential development of other pharmaceutical forms for other routes of administration and for quality risk management, no data regarding this matter is available to date. In this study, the exploration of the molecule's behaviour under hydrolytic, oxidative and photolytic conditions was carried out experimentally and supported by density functional theory (DFT) studies. It comes out that umifenovir is sensitive to these stress conditions giving rise to 6 structurally characterized degradation products. The one-electron oxidation process produced on the sulphur atom is probably the main cause of umifenovir degradation with reference to the structures of the degradation products formed and the DFT data. [ABSTRACT FROM AUTHOR]

• A novel fluorescent probe PDS based on camphor was designed and synthesized. • The probe PDS was used for highly sensitive and specific detection of Co2+ within a short time. • The probe PDS could successfully detect Co2+ both in real water samples and in fresh vegetables. Cobalt is an essential micronutrient for human beings. The excessive intake of cobalt may lead to heart-related diseases. In this work, a novel fluorescent probe 1,1′-(((6,11,11-trimethyl-6,7,8,9-tetrahydro-6,9-methanopyridazino[4,5-b]quinoxaline-1,4-diyl)bis(azanylylidene))bis(methanylylidene))bis(naphthalen-2-ol) (PDS) was synthesized from camphor. The probe PDS could be utilized to selectively recognize Co2+ over other metal ions. There is a good linear relationship between fluorescence intensity of PDS and Co2+ concentration within 0–20 μM, and its detection limt was found to be 0.925 μM, which is far lower than the national standard for cobalt in drinking water in China. The possible coordination mechanism of PDS with Co2+ was determined by nuclear magnetic resonance (NMR), high resolution mass spectrometry (HRMS) and density functional theory (DFT). The probe PDS was also successfully applied in detection of Co2+ in tap water and fresh vegetables. [ABSTRACT FROM AUTHOR]

Given the positive effects of jet bubble reactors as particulate matter (PM) traps, a new integrated technology was investigated, termed here the spray-and-scattered-bubble process. The main goal was to demonstrate that it can satisfy ultra-low emission limits for the ammonia-based desulfurization process, where the aerosol generated by the spraying droplets is further removed by the bubbling step in one device. Compared with the conventional spray-only method, this new technology generates a lower particulate level based on the same desulfurization efficiency, and the particulate size has an effectively unimodal distribution with a main size range from 0.156 μm to 1.64 μm. The removal mechanism under the new technology is further explored by density functional theory (DFT) and a large adsorption energy between was found to exist between the sulfites and (NH 4) 2 SO 4 particles. The process parameters that affect the particulate emission were studied using lab-scale tests, by changing the SO 2 concentration, the immersion depth and the liquid/gas ratio. The results indicated that the amount of particulate matter significantly increases in the presence of SO 2 in the flue gas and was positively correlated with the SO 2 concentration. The liquid/gas ratio showed a positive correlation with the particulate matter emissions, while the immersion depth is closely tied to the inhibition effect. To further verify its potential, long-term experiments with actual flue gas were performed in a 5000 Nm3/h pilot platform. The "daily mean results" showed that the PM emission concentration was 5 mg/m3, which is far below the ultra-low limits now proposed in China. • An integrated technology was studied to meet the PM ultra-low emission limit. • The removal mechanism is explored by quantum chemistry calculation. • The field test of pilot-scale spray-and-scattered-bubble facility is built. [ABSTRACT FROM AUTHOR]

High concentration of Li, associated with coal, has been found in the Guanbanwusu coal Mine, Inner Mongolia, China. Earlier studies suggested that the lithium came from the Yinshan Paleoland during the peat-forming stage. The results of Li isotope determinations and calculations based on density functional theory (DFT) indicated that the lithium in the peat was released into the pore water and adsorbed by kaolinite edge surfaces (octahedral layers and/or tetrahedral layers) in the subsequent diagenesis and coalification. Alternatively, the Li of the partings, the floor, and the roof of the No. 6 coal seam also likely originated from the underlying bauxite of the Benxi Formation. Specifically, we determined the Li isotopic fractionations produced in chelation by small carboxylate (Δ7/6Li organolithium-aq = −0.35‰), in adsorption onto kaolinite edge surfaces (Δ7/6Li octahedral layer-aq = 4.36‰, Δ7/6Li tetrahedral layer-aq = −4.53‰), and during incorporation into the lattices (Δ7/6Li Al2-aq = −8.2‰ and Δ7/6Li Al1-aq = −11.9‰). Combining these results with the δ7Li of 3.37 ± 0.13‰ for the moyite of the Yinshan Paleoland, we deduced a theoretical δ7Li range for the No. 6 coal seam and the partings, 2.85–7.38‰, exactly covering the determined δ7Li values of the coal and the partings. However, only the partings plotted in the theoretical δ7Li range of 1.13–5.66‰ assuming the bauxites (with δ7Li 1.30 ± 0.03‰) as the lithium source. During weathering and deposition, conversion of structurally incorporated Li within the grain boundaries of polycrystalline minerals of the bauxites to adsorbed Li was inferred to explain the Li isotope excursion in the latter case. • To discuss the Li enrichment in coals by DFT calculations and MC-ICP-MS analyses • The coals and the partings of the No. 6 coal seam may have different Li sources. • Occurrence modes of light element Li in the coals and the partings are inferred. [ABSTRACT FROM AUTHOR]

• The Wulantuga and Lincang in China are both giant coal-hosted Ge deposits. • Ge in the high-Ge coals is predominantly associated with the organics. • The binding nature of Ge-O complexes in five acidic hydroxyls were investigated. • Phenolic hydroxyls are most likely the bonding sites for Ge. The Wulantuga and Lincang germanium deposits in China are both giant coal-hosted Ge deposits. It is a consensus that the enriched Ge in the high-Ge coals is predominantly associated with the organics, but the specific bonding sites for Ge still remain unclear. In the present study, conventional spectral analyses (13C NMR and KBr-FTIR) and the density functional theory (DFT) calculations were used to investigate the functional groups responsible for Ge accumulation in the Wulantuga and Lincang deposits. The analytical results of the semi-quantitative NMR and FTIR suggest that the phenolic hydroxyls suffered alteration by HCl-HF treatment and are most likely the bonding sites for Ge by comparing the structures of the micronized and acid demineralized huminites from two high-Ge coals. Five acidic hydroxyl containing model compounds (catechol, phenol, ethanol, acetic acid, and benzoic acid) were selected to investigate the binding nature of Ge-O complexes, and the results indicate that phenolic hydroxyls have higher reactivity relative to other groups due to the easier exposure of oxygen by hydrogen dissociation, which is the key step for the formation of Ge-O complexes. Both the experiment and calculation results support the significance of phenolic hydroxyls for Ge fixation in the two deposits, but the present study does not exclude the possible contribution of other O-containing groups. This study facilitates understanding the mode of occurrence of Ge in the high-Ge coals and revealing the mechanism of the organic association of Ge in the coal-hosted Ge ore deposits from the perspective of coal structure. [ABSTRACT FROM AUTHOR]

Radix puerariae-a popular traditional Chinese medicine-is used for the treatment of diarrhea, acute dysentery, deafness, and cardiovascular diseases. It can also be used as an effective antioxidant and has been tested as an anticancer drug. Daidzein and puerarin are its main active compounds. The present contribution was focused on experimental and theoretical studies of the 1 H and 13 C NMR chemical shifts and nuclear magnetic shielding parameters of daidzein and puerarin. Experimental data were gained by exploring standard one-dimensional spectra and a set of two-dimensional measurements: COSY, HSQC, and HMBC. The theoretical gauge independent atomic orbital density functional theory supporting studies, were performed to determine shielding constants and chemical shifts in vacuum and methanol-d4 solvent. The correlation between experimental and theoretical data was fairly good, especially when the DFT/PBE0 approach was used. The molecular properties of daidzein and puerine related to antiradical activity were studied in the context of a single-step hydrogen atom transfer mechanism and its correlation with 13 C NMR chemical shifts. Graphical abstract Electron spin density distribution for daidzein radical.

A detailed chemical investigation of the Chinese soft coral Lemnalia flava yielded four new nardosinane-type sesquiterpenoids (1-4), one new neolemnane-type sesquiterpenoid (5), and one new sesquiterpenoid with an uncommon 6/9 fused bicyclic skeleton (6), together with two known related compounds (7 and 8). The structures and absolute configurations of 1-8 were determined on the basis of extensive spectroscopic data analyses, X-ray diffraction analysis, chemical reactions, and computer-assisted structural elucidation including 13 C NMR data calculation, residual dipolar coupling based NMR analysis, and time-dependent density functional theoryelectronic circular dichroism calculation. Plausible biogenetic pathways of two uncommon sesquiterpenoids (4 and 6) were proposed.

p-Arsanilic acid ( p-ASA) is an emerging organoarsenic pollutant comprising both inorganic and organic moieties. For the efficient removal of p-ASA, adsorbents with high adsorption affinity are urgently needed. Herein, amine-modified UiO-67 (UiO-67-NH 2 ) metal-organic frameworks (MOFs) were synthesized, and their adsorption affinities toward p-ASA were 2 times higher than that of the pristine UiO-67. Extended X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculation results revealed adsorption through a combination of As-O-Zr coordination, hydrogen bonding, and π-π stacking, among which As-O-Zr coordination was the dominant force. Amine groups played a significant role in enhancing the adsorption affinity through strengthening the As-O-Zr coordination and π-π stacking, as well as forming new adsorption sites via hydrogen bonding. UiO-67-NH 2 s could remove p-ASA at low concentrations (<5 mg L -1 ) in simulated natural and wastewaters to an arsenic level lower than that of the drinking water standard of World Health Organization (WHO) and the surface water standard of China, respectively. This work provided an emerging and promising method to increase the adsorption affinity of MOFs toward pollutants containing both organic and inorganic moieties, via modifying functional groups based on the pollutant structure to achieve synergistic adsorption effect.