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In the process of microemulsion flooding, microemulsion phase state may be affected by the adsorption of core and the distribution of oil and water, and the upper phase, the middle phase or the lower phase microemulsion will appear. Accurate description of microemulsion phase state and quantitative discrimination of equilibrium phase composition are of great theoretical value and research significance for the design of microemulsion flooding system and improving the recovery efficiency of microemulsion. Therefore, in this paper, microemulsion phase model is deeply studied. Aiming at the difficulty of solving the existing Hand model and the unknown parameters of the improved HLD-NAC model, we introduce the binodal curve range parameter D and the asymmetric migration degree parameter B, and establish a new phase behavior description method of the binodal curve, the two-phase plait point lines and the III-phase node line. Then the phase discrimination programming of microemulsion was carried out, and the change laws of phase number, phase type and mass fraction of equilibrium phases of any microemulsion system under different salinity were revealed. The results show that the simulation results of microemulsions accord with the salinity scanning law, and can accurately identify the complex microemulsion phase states.

Ordered macroporous materials with rapid mass transport and enhanced active site accessibility are essential for achieving improved catalytic activity. In this study, boron phosphate crystals with a three-dimensionally interconnected ordered macroporous structure and a robust framework were fabricated and used as stable and selective catalysts in the oxidative dehydrogenation (ODH) of propane. Due to the improved mass diffusion and higher number of exposed active sites in the ordered macroporous structure, the catalyst exhibited a remarkable olefin productivity of ~16 golefin gcat−1 h−1, which is up to 2–100 times higher than that of ODH catalysts reported to date. The selectivity for olefins was 91.5% (propene: 82.5%, ethene: 9.0%) at 515 °C, with a propane conversion of 14.3%. At the same time, the selectivity for the unwanted deep-oxidized CO2 product remained less than 1.0%. The tri-coordinated surface boron species were identified as the active catalytic sites for the ODH of propane. This study provides a route for preparing a new type of metal-free catalyst with stable structure against oxidation and remarkable catalytic activity, which may represent a potential candidate to promote the industrialization of the ODH process.

In this paper, the influence of humic acid (HA) and fulvic acid (FA) on biomineralization behaviour was evaluated. The results showed HA and FA did not obviously inhabit or promote the precipitation of U-phosphate minerals. The data from molecular dynamic simulation indicated that the free energy for the dissociation of uranyl the PO43− -uranyl was 202.49 kJ/mol, which was much larger than that form HA-uranyl (88.3 kJ/mol). These simulated results revealed the less competitiveness of HA and FA with PO43− for uranyl and explained why HA and FA had less impacted on the formation of U-phosphate minerals. However, the influence of HA/FA on the morphology was obvious, the microstructure of the bio-minerals changed from small particles to lamellar stacking structure with the addition of HA or FA. The findings of this study are helpful for us to gain a better understanding natural U-phosphate biomineralization behaviour.

Coastal wetlands can serve as a considerable sink for carbon (C) gases. However, the capacity for wetlands to serve as more permanent C and N sinks over the long term is less clear given the time dependence of sediment deposition, organic matter decomposition, and anthropogenic land use change. In this study, we compare the short-term (decadal scale) and long-term (millennial scale) C and N accumulation rates estimated using 137Cs and radiocarbon dating of vibracores collected from a freshwater coastal wetland in the Louisiana Mississippi River deltaic plain (Atchafalaya River delta). The mean short-term (60 yrs) sediment accumulation rate was 1.4 cm/yr while the mean rate of long-term (100–1000 yrs) sediment accumulation was an order of magnitude lower at 0.12 cm/yr. Annual rates of C and N accumulated over the past several thousand years were approximately 10% of that over the past 60 years after correcting for bulk density. These results are similar to other coastal wetlands and suggest that time scale must be considered in determining the relative permanence of C and N storage in coastal wetland soils. This difference is especially important for assessing the role of C cycling in relation to global change models and N cycling related to water quality in accurately quantifying the role of coastal deltaic fresh water wetlands in regulating these biogeochemical cycles.

Although there have been numerous studies focusing on plants' roles in methane (CH4) emissions, the influencing mechanism of wetland plants on nitrous oxide (N2O) emissions has rarely been studied. Here, we test whether wetland plants also play an important role in N2O emissions. Gas fluxes were determined using the in situ static flux chamber technique. We also carried out pore-water extractions, sedge removal experiments and tests of N2O transportation. The brackish marsh acted as a net source of both CH4 and N2O. However, sedge plants played the opposite role in CH4 and N2O emissions. The removal of the sedges led to reduced CH4 emissions and increased accumulation of CH4 inside the sediment. Apart from being a conduit for CH4 transport, the sedges made a greater contribution to CH4 oxidation than CH4 production. The sedges exerted inhibitory effects on the release of N2O. The N2O was barely detectable inside the sediment in both vegetated and vegetation-removed plots. The denitrification measurements and nitrogen addition (the addition rates were equal to 0.028, 0.056 and 0.112 g m−2) experiments suggest that denitrification associated with N2O production occurred mainly in the surface sediment layer. The vascular sedge could transport atmospheric N2O downward into the rhizosphere. The rhizospheric sediment, together with the vascular sedge, became an effective sink of atmospheric N2O.

Oxidative dehydrogenation of light alkanes to alkenes is an attractive alternative route for industrial direct dehydrogenation because of favorable thermodynamic and kinetic characteristics, but encounters difficulties in selectivity control for alkenes because of over-oxidation reactions that produce a substantial amount of undesired carbon oxides. Recent progress has revealed that boron nitride is a highly promising catalyst in the oxidative dehydrogenation of light alkanes because of its superior selectivity for and high productivity of light alkenes, negligible formation of CO2, and remarkable catalyst stability. From this viewpoint, recent works on boron nitride in the oxidative dehydrogenations of ethane, propane, butane, and ethylbenzene are reviewed, and the emphasis of this viewpoint is placed on discussing the catalytic origin of boron nitride in oxidative dehydrogenation reactions. After analyzing recent progress in the use of boron nitride for oxidative dehydrogenation reactions and finding much new evidence, we conclude that pure boron nitride is catalytically inert, and an activation period is required under the reaction conditions; this process is accompanied by an oxygen functionalization at the edge of boron nitride; the B-O species themselves have no catalytic activity in C-H cleavage, and the B-OH groups, with the assistance of molecular oxygen, play the key role in triggering the oxidative dehydrogenation of propane; the dissociative adsorption of molecular oxygen is involved in the reaction process; and a straightforward strategy for preparing an active boron nitride catalyst with hydroxyl groups at the edges can efficiently enhance the catalytic efficacy. A new redox reaction cycle based on the B-OH sites is also proposed. Furthermore, as this is a novel catalytic system, there is an urgent need to develop new methods to optimize the catalytic performances, clarify the catalytic function of boron species in the alkane ODH reactions, and disclose the reaction mechanism under realistic reaction conditions.

Bioretention system is one of the most used green stormwater infrastructures (GSI), and its media is a key factor in reducing runoff water volume and purifying water quality. Many studies have investigated media improvement to enhance the pollutant removal capacity. However, the long-term cumulative effect and microbial effect of pollutants in the modified-media bioretention system is less known. This study investigated the cumulative effect of pollutants and their influence on microbial characteristics in conventional and modified media bioretention system. The addition of modifiers increased the background content of pollutants in the media, and the accumulation of pollutants in planting soil (PS) and bioretention soil mixing + water treatment residuals (BSM+WTR) was relatively higher after the simulated rainfall experiment. The accumulation of pollutants led to a decrease in dehydrogenase activity, and an increase in urease and invertase activities. Ten dominant bacterial species at the phylum level were found in all bioretention systems. The relative abundances of the bacteria with good viability under low nutritional conditions decreased, while the species which could live in the pollutant-rich environment increased. The accumulation of pollutants in the bioretention system led to the extinction of some functional microorganisms. The better the effects of modified media on pollutant removal showed, the more obvious effect on the media micro-ecosystem was. To ensure the long-term efficient and stable operation of the modified-media bioretention system, we recommend balancing the pollutant removal efficiency and cumulative effect in modified-media bioretention systems.

The synthesis, Eu3+ complexation, and selective solvent extraction of Am3+ over Eu3+ in nitric acid solution by 2-carboxamido-6-(1H-pyrazol-3-yl)-pyridines (A-PzPy) ligands were described. Without the aid of any lipophilic anion source, A-PzPy ligands in methyl isobutyl ketone (MIBK) diluent demonstrated a more favorable affinity of Am3+ than Eu3+ at high acidity levels. Slope analysis showed the formation of 1:2 metal/ligand extracted species. The extraction was a spontaneous exothermic process. The analyses of fluorescence titration, Fourier transform infrared (FT-IR), Raman, time-resolved laser fluorescence spectrum (TRLFS), electrospray ionization mass spectrometry (ESI-MS), conductivity and microcalorimetric titration revealed that the composition of complex is [Eu(NO3)2(H2O)∙2(Et-p-Tol-A-PzPy)](NO3). Combining the results of solvent extraction and complexation study, the extraction mechanism was proposed. Furthermore, the stability constants (log β) and thermodynamic parameters (ΔH, ΔS, ΔG) for complexation of Eu3+ with Et-p-Tol-A-PzPy were also presented.

Perchlorate (ClO4−), a persistent inorganic compound, has harmful effects on human health. Natural ClO4− is formed in the atmosphere and enters into the surface environment through deposition. However, the knowledge on the occurrence, spatial variability and sinks of natural ClO4− in different environments remains limited, especially in the polar regions. Here, we investigate the sources and sinks of ClO4− in soil collected in three ice-free areas in coastal Antarctica, where the research stations and wildlife colonies are mainly distributed. No statistically significant difference in ClO4− concentrations between sites near and away from the stations suggests that local human presence is not a significant source of ClO4− in soil. Concentrations of ClO4− in soil from wildlife colonies are not significantly higher than those from sites with no intense wildlife activities, indicating that wildlife activities have no significant influences on ClO4− in soil. Thus, atmospherically formed ClO4− is the main source for soil in Antarctica. In general, ClO4− concentrations (0.1–5.1 μg kg−1) in soil in this study are much lower than those in the arid environments and comparable to those in the unsaturated zones. Leaching by snow meltwater may be the main sink for ClO4− in soil, and deeper depths for aqueous migration may contribute to the lower ClO4− concentrations in Antarctic surface soil compared to the values in the arid areas with low precipitation amount. Due to the biological origin of NO3−, no correlation between NO3− and ClO4− in soil is observed in this study, different from the observations in arid areas. In addition, no significant correlation is observed between organic matter contents and ClO4− concentrations in soil, suggesting that biological reduction is not an important sink for ClO4− in Antarctic soil.

Lanthanum modified zeolite (LMZ) has been proven to be an effective inactivation agent for lake internal phosphorus load control. However, its performance in the co-sequestration of P and heavy metal is still unclear. Thus, simultaneous adsorption of phosphate and zinc by LMZ was investigated in this study, and its co-inactivation performance in sediment was also verified. Separate adsorption capacities of LMZ for phosphate and zinc were 2.31 and 0.367 mmol/g, respectively. In co-adsorption scenario, removal rate of zinc (0.15 mmol/L) increased from 73.53 to 84.60% when co-existing phosphate increased from 0.097 to 0.48 mmol/L (pH 6.5), while zinc had an inapparent impact on phosphate adsorption. Furthermore, an increase of background NaCl concentration in the system inhibited zinc removal by 25%, indicating that part of zinc was physically adsorbed by the zeolite fraction of LMZ. XPS and Raman spectra suggested that phosphate in the simultaneous adsorption system was innerspherically adsorbed by lanthanum oxide component of LMZ, while zinc was adsorbed by forming both outer-sphere complex and inner-sphere complex. Part of zinc could chelate with the adsorbed phosphate, forming phosphate bridged ternary complex and enhancing zinc removal. Finally, a lab-scale inactivation experiment showed that simultaneous stabilization of P and zinc in sediment could be achieved by dosing 5% weight percentage LMZ, making it a promising inactivation agent in the future.

Candidatus Accumulibacter phosphatis (CAP) and its clade-level micro-diversity has been associated with and implicated in functional differences in phosphorus removal performance in enhanced biological phosphorus removal (EBPR) systems. Side-stream EBPR (S2EBPR) is an emerging process that has been shown to present a suite of advantages over the conventional EBPR design, however, large knowledge gaps remain in terms of its underlying ecological mechanisms. Here, we compared and revealed the higher-resolution differences in microbial ecology of CAP between a full-scale side-stream EBPR configuration and a conventional A2O EBPR process that were operated in parallel and with the same influent feed. Even though the relative abundance of CAP, revealed by 16S rRNA gene amplicon sequencing, was similar in both treatment trains, a clade-level analysis, using combined 16S rRNA-gene based amplicon sequencing and oligotyping analysis and metagenomics analysis, revealed the distinct CAP microdiversity between the S2EBPR and A2O configurations that likely attributed to the improved performance in S2EBPR in comparison to conventional EBPR. Furthermore, genome-resolved metagenomics enabled extraction of three metagenome-assembled genomes (MAGs) belonging to CAP clades IIB (RCAB4-2), IIC (RC14) and II (RC18), from full-scale EBPR sludge for the first time, including a distinct Ca. Accumulibacter clade that is dominant and associated only with the S2EBPR configuration. The results also revealed the temporally increasing predominance of RC14, which belonged to Clade IIC, during the implementation of the S2EBPR configuration. Finally, we also show the existence of previously uncharacterized diversity of clades of CAP, namely the clades IIB and as yet unidentified clade of type II, in full-scale EBPR communities, highlighting the unknown diversity of CAP communities in full-scale EBPR systems.

Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) concentration, saturation and fluxes in rivers (Beitang drainage river, Dagu drainage rive, Duliujianhe river, Yongdingxinhe river and Nanyunhe river) of Tianjin city (Haihe watershed) were investigated during July and October in 2014, and January and April in 2015 by static headspace gas chromatography method and the two-layer model of diffusive gas exchange. The influence of environmental variables on greenhouse gases (GHGs) concentration under the disturbance of anthropogenic activities was discussed by Spearman correlative analysis and multiple stepwise regression analysis. The results showed that the concentration and fluxes of CO2, CH4 and N2O were seasonally variable with >winter>fall>summer, spring>summer>winter>fall and summer>spring>winter>fall for concentrations and spring>summer>fall>winter, spring>summer>winter>fall and summer>spring>fall>winter for fluxes respectively. The GHGs concentration and saturation were higher in comprehensively polluted river sites and lower in lightly polluted river sites. The three GHGs emission fluxes in two sewage draining rivers of Tianjin were clearly higher than those of other rivers (natural rivers) and the spatial variation of CH4 was more obvious than the others. CO2 and N2O air-water interface emission fluxes of the sewage draining rivers in four seasons were about 1.20-2.41 times and 1.13-3.12 times of those in the natural rivers. The CH4 emission fluxes of the sewage draining rivers were 3.09 times in fall to 10.87 times in spring of those in the natural rivers in different season. The wind speed, water temperature and air temperature were related to GHGs concentrations. Nitrate and nitrite (NO3-+NO2--N) and ammonia (NH4+-N) were positively correlated with CO2 concentration and CH4 concentration; and dissolved oxygen (DO) concentration was negatively correlated with CH4 concentration and N2O concentration. The effect of human activities on carbon and nitrogen cycling in river is great.

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.

In recent years, various kinds of nanomaterials based invasive or non-invasive deep neural stimulation tools are developed for modulating neural system and illuminating the relationship between neural circuits and specific behaviors. For better modulation of neural system and clinical application, the neural stimulation nanotools should be optimized. In this work, we demonstrated a novel non-invasive neural modulation approach relying on magnetic field, which is realized by modifying magnetic nanoparticles (MNPs) with anti-His antibody and inserting His-tag at specific position of TRPV4 to target the activation of TRPV4 ion channel. The activated TRPV4 ion channel could induce the calcium influx by in vitro calcium imaging assay in cultured neurons. This study showed that this approach can improve the calcium transient compared with unmodified MNPs. Furthermore, this approach was confirmed in freely moving mice presenting valid magnetic control of rotation around the body-axis and freezing of gait. This work demonstrates that TRPV4 ion channel can be activated by MNPs based nanotool, which provides a new alternative way for achieving magnetic stimulation in deep-brain circuits. This work also can serve as a useful validation study for magnetogenetics.

Many meta-analyses have been performed to study the efficacy of cervical disc arthroplasty (CDA) compared with anterior cervical discectomy and fusion (ACDF); however, there are few data referring to adjacent segment within these meta-analyses, or investigators are unable to arrive at the same conclusion in the few meta-analyses about adjacent segment. With the increased concerns surrounding adjacent segment degeneration (ASDeg) and adjacent segment disease (ASDis) after anterior cervical surgery, it is necessary to perform a comprehensive meta-analysis to analyze adjacent segment parameters.To perform a comprehensive meta-analysis to elaborate adjacent segment motion, degeneration, disease, and reoperation of CDA compared with ACDF.Meta-analysis of randomized controlled trials (RCTs).PubMed, Embase, and Cochrane Library were searched for RCTs comparing CDA and ACDF before May 2016. The analysis parameters included follow-up time, operative segments, adjacent segment motion, ASDeg, ASDis, and adjacent segment reoperation. The risk of bias scale was used to assess the papers. Subgroup analysis and sensitivity analysis were used to analyze the reason for high heterogeneity.Twenty-nine RCTs fulfilled the inclusion criteria. Compared with ACDF, the rate of adjacent segment reoperation in the CDA group was significantly lower (p.01), and the advantage of that group in reducing adjacent segment reoperation increases with increasing follow-up time by subgroup analysis. There was no statistically significant difference in ASDeg between CDA and ACDF within the 24-month follow-up period; however, the rate of ASDeg in CDA was significantly lower than that of ACDF with the increase in follow-up time (p.01). There was no statistically significant difference in ASDis between CDA and ACDF (p.05). Cervical disc arthroplasty provided a lower adjacent segment range of motion (ROM) than did ACDF, but the difference was not statistically significant.Compared with ACDF, the advantages of CDA were lower ASDeg and adjacent segment reoperation. However, there was no statistically significant difference in ASDis and adjacent segment ROM.

A novel metal-organic frameworks (MOFs) UiO-66-Schiff base was successfully synthesized by post-synthetic modification to investigate the cobalt sorption behaviour in simulated wastewater. The thermodynamic and kinetic parameters demonstrated the sorption process to be spontaneous, endothermic and pseudo-second-order chemisorption. The maximum cobalt sorption capacity of the synthetic MOFs was approximately 256 mg g −1 , and the stable and porous Schiff base-derived material displayed excellent regenerated availability with at least five recycle applications. Moreover, density functional theory (DFT) calculations have been performed to explore the coordination modes between cobalt ions and ligands in UiO-66-Schiff base, which revealed that the Schiff base group could take cobalt (II) from cobalt ions hydrates [Co(H 2 O) 6 ] 2+ and Co-CHES (Co-2-(cyclohexylamino)-ethane sulfonic acid) complex [Co(CHES)(H 2 O) 5 ] + to form [CoL N (H 2 O) 5 ] 2+ or [CoL O (H 2 O) 4 ] + . This study offers a facile approach for developing Schiff base modification MOF sorption of cobalt (II) ions from aqueous solutions and provides theoretical and practical guidance on new MOF designs for selective removal of radionuclides.

Silicon carbide fiber-reinforced silicon carbide matrix composites have been investigated for their use as structural materials for advanced nuclear reactor. Although quite a number of researches have been devoted to probe the effects of irradiation on various properties of the composites, there is little known about the atomistic mechanism for irradiation resistance. In this study, a two-temperature model has been used to investigate the irradiation damage of SiC/Gra/SiC composites, which includes three parts and two SiC/C interfaces, two single crystal cubic silicon carbide on two sides and a few graphene sheets in the middle part. By simulating 100 keV displacement cascades, we find that the number of defects in the reinforcement is larger than that in the matrix, which indicates the damage in the reinforcement is more serious than that in the matrix. Moreover, we explicitly investigate the damage behavior of the interphase graphene layers and find that some atoms in one graphene sheet form many new chemical bonds with atoms in another one, which leads to the transition from sp 2 to sp 3 hybridization. The newly formed chemical bonds link the different graphene layers and make graphene-like electronic structure more “diamond-like”, enhancing the irradiation resistance of the matrix.

Boron nitride containing hydroxyl groups efficiently catalysed oxidative dehydrogenation of ethane to ethylene, offering rather high selectivity (95%) but only small amount of CO2 formation (0.4%) at a given ethane conversion of 11%. Even at high conversion level of 63%, the selectivity of ethylene retained at 80%, which is competitive with the energy-demanding industrialized steam cracking route. A long-term test for 200 h resulted in stable conversion and product selectivity, showing the excellent catalytic stability. Both experimental and computational studies have identified that the hydrogen abstraction of B-OH groups by molecular oxygen dynamically generated the active sites and triggered ethane dehydrogenation.

Methane (CH4) emissions are low in the coastal zone due to a higher redox poise, related to sulfate reduction. However, river deltas are a potential source of CH4 flux in coastal zones globally, due to fresh condition and high primary production. The goal of this study was to seasonally measure CH4flux at three different geomorphic settings (newly forming island, river channel bottom and established freshwater marsh) within the Wax Lake Delta, Louisiana, USA. CH4 flux rates were 386 ± 327 mg C m−2 d−1 in March and 2859 ± 1286 mg C m−2 d−1 in June at the freshwater marsh site. At the island site, CH4 flux was significantly smaller at 7.94 ± 3.57 mg C m−2 d−1 in March and 215 ± 153 mg C m−2 d−1 in June while at adjacent river channel bottom site, CH4 flux was lowest at 2.49 ± 3.38 mg C m−2 d−1 in March and 19.5 ± 1.12 mg C m−2 d−1 in June at the air-water interface. CH4 emission rates show significant spatial heterogeneity with rates up to two orders of magnitude greater at the marsh site at the periphery of the delta, related to greater soil total C. Therefore regions within the active delta do not provide a significant source of methane, due to a lack of soil C, despite freshwater conditions. However, marshes at the periphery within the halo of fresh water, populated with established plant communities can be significant hotspots of CH4 emissions, despite their location within the coastal zone.

Static floating chambers (FCs) are the conventional method to measure CH4 fluxes across the water-air interface in ponds, while thin boundary layer (TBL) modelling is increasingly used to estimate CH4 fluxes. In this study, both FCs measurements and TBL models of gas transfer velocity were used to determine CH4 evasion from aquaculture ponds in southeastern China. The surface water CH4 concentrations ranged from 0.4 to 9.1 μmol L-1 with an average of 4.8 ± 0.8 μmol L-1. CH4 flux was always positive, indicating the ponds as a persistent CH4 source to air. Mean CH4 flux based on different TBL models showed large variations, ranging between 19 and 316 μmol m−2 h−1. Compared against the direct measurement FCs, three TBL models developed for the open sea, flowing estuarine system and lentic ecosystem (TBLW92a, TBLRC01, and TBLCL98, respectively) overestimated CH4 emission by 40–200%, while the wind tunnel-based TBL model (TBLLM86) underestimated CH4 emission. Two TBL models developed for lakes (TBLW92b and TBLCW03) gave estimates similar to FCs.

The adsorption of uranyl on hydroxylated α-SiO2(001) in the presence of a series of anionic ligands, i.e. OH−, CO 3 2 - , NO 3 - , H 2 PO 4 - , HPO 4 2 - , CH3COO− (Ac−), C6H5COO− ( PhCO 2 - ), C6H5O− (PhO−), was studied by the periodic density functional theory (DFT) implemented in the Vienna ab initio simulation package (VASP). For the ligands other than OH− and PhO−, only the bidentate coordination modes to the uranyl were considered. The excess charge effect of a charged system was first evaluated by constructing models with net charge as is or neutralized by creating defect at the bottom of silica, and the results show that a neutralized model, even with defects, is more realistic than the charged ones. All uranyl species prefer to bind with the deprotonated site ( O−) rather than the protonated one ( OH), which suggests that the increase of pH, which leads to the deprotonation of the surface, may enhance the uranyl adsorption. On the other hand, the anionic ligands, which are formed at higher pH, have negative effects. The weaker acidic ligands, such as H2CO3, H3PO4 and H2O, whose speciation in solutions is sensitive to the fluctuation of pH, have more complex effect on the uranyl adsorption than strong acids or bases. Humic substances may coordinate with uranyl through carboxyl and phenolic groups, with the carboxyl group bound stronger. The ternary complexes with one bidentate (or monodentate) anion and one (or two) H2O as ligands, which leads to the uranyl penta-coordinated in its equatorial plane, are more favorable than other configurations when bound to the same anionic ligand. Both the charged nature and the coordination behavior of an anionic ligand are relevant to its ability to influence the adsorption of uranyl on the mineral surface. In addition, the uranyl species adsorbed at the surface functionalized by anionic ligands were also addressed, and the functionalized surfaces have weaker interaction with hydrated uranyl dication.

The coalescence processes of two ( 6 , 0 ) single-walled carbon nanotubes are investigated via coaxial collision based on the self-consistent-charge density-functional tight-binding molecular dynamics method. According to the structure characteristics of the nanotubes, five impact cases are studied to explore the coalescence processes of the nanotubes. The simulation shows that various kinds of carbon nanomaterials, such as graphene sheets, graphene nanoribbons, and single-walled carbon nanotubes with larger diameters, are created after collision. Moreover, some defects formed in the carbon nanomaterials can be eliminated, and even the final configurations which are originally fragmented can almost become intact structures by properly quenching and annealing.

Changes in metal concentrations in the litter of Potamogeton crispus were monitored during a consecutive 40-day in situ decomposition experiment using the litterbag method. The accumulation index was calculated and used to indicate the changes in the metals in litter. The results showed that the concentrations of Al, Cd, Cr, Fe, Mn, and Pb in litter increased significantly during the decomposition, while Cu and Zn concentrations decreased dramatically. Significant positive correlations were found between the concentrations of Al, Cr, Fe, and Mn and between Cu and Zn. Moreover, Cu and Zn both negatively correlated with Al and Fe. The remaining dry mass was negatively correlated with Al and Fe concentrations but positively correlated with Cu and Zn concentrations. Generally the accumulation index values of metals other than Al were less than one, indicating that the litter of P. crispus acted as a source of metals to the surrounding water body. Al was the only metal that showed continuous net accumulation in litter. The net accumulation of Fe and Mn in litter during the last 10 days of the experiment may indicate the precipitation of Fe- and Mn-oxides. It was estimated that 160 g/m(2) (dry weight) P. crispus was decomposed in 40 days. This was equivalent to releasing the following amounts of metals: 0.01 mg Cd, 0.03 mg Cr, 0.71 mg Cu, 0.55 mg Mn, 0.02 mg Pb and 13.8 mg Zn into surrounding water, and accumulating 149 mg Al and 11 mg Fe, in a 1m(2) area.

Coastal marshes have a significant capacity to sequester carbon; however, sea-level rise (SLR) is expected to result in prolonged flooding and saltwater intrusion in coastal regions. To explore the effects of SLR projections on net CO2 uptake in coastal marshes, we conducted a "double-check" investigation, including the eddy covariance (EC) measurements of the CO2 fluxes in subtropical coastal marshes along inundation and salinity gradients, in combination with a mesocosm experiment for analyzing CO2 flux components under waterlogging and increased salinity conditions. During the same measurement periods, the net ecosystem CO2 exchange (NEEEC based on the EC dataset) in an oligohaline marsh was higher than that in a low-elevation mesohaline marsh, whereas the NEEEC was lower than that in a high-elevation freshwater marsh. The declines in NEEEC between the marshes could be attributed to a greater decrease in gross primary production relative to ecosystem respiration. Waterlogging slightly increased the NEEms (NEE based on the mesocosms) because of inhibited soil respiration and slight changes in plant photosynthesis and shoot respiration. However, the NEEms measured during the drainage period decreased significantly due to the stimulated soil respiration. The NEEms decreased with increasing salinity (except under mild salinity), and waterlogging exacerbated the adverse impacts of salinity. The amplificatory effect of decreases in both leaf photosynthesis and growth under hydrological stresses contributed more to reduce the NEEms than to respiratory effluxes. Both waterlogging and increased salinity reduced the root biomass, soil microbial biomass, and activities of assayed soil enzymes (except for cellulase under waterlogging conditions), leading to limited soil respiration. The declines in plant growth, photosynthesis, and soil respiration could also be attributed to the decrease in soil nutrients under waterlogging and increased salinity conditions. We propose that the coupling of SLR-driven hydrological effects lowers the capacity of CO2 uptake in subtropical coastal marshes.

Dissolved concentrations, saturation status, and emission fluxes of greenhouse gases (GHGs) in two reclamation mariculture ponds in the Bohai Gulf, China, were measured using the static headspace gas chromatography method and computed using a two-layer model of diffusive gas exchange. The study was conducted during August 2016 to assess diurnal variations in GHGs emissions. The main influencing factors of GHGs emissions from the ponds under the disturbance of artificial management were identified using Spearman correlation analyses and multiple stepwise regression analyses. Results showed that dissolved GHGs concentrations were stable throughout the day, whereas GHGs emission fluxes showed a clear diurnal variation with larger daytime values. The diurnal variation of N2O emission fluxes was greater than that of CO2 and that of CH4. Results also showed that pH of pond water was negatively correlated with CO2 and N2O emission fluxes and that air temperature was positively correlated with CH4 and N2O emission fluxes. In addition, ammonia (NH4+-N) was positively correlated with CH4 emission fluxes; water temperature and salinity were positively correlated with N2O emission fluxes. The estimated annual emissions from the reclamation aquaculture in Tianjin and the Bohai Rim region were 2.53 × 105 kg C–CO2, 6.94 × 103 kg C–CH4 and 1.11 × 103 kg N–N2O, and 3.42 × 107 kg C–CO2, 9.36 × 105 kg C–CH4 and 1.50 × 105 kg N–N2O respectively, indicating the important contribution of this fishery sector to GHGs emissions.

Olive-green few-layered BiOI with expanded spacing of the (001) facets and oxygen vacancy is successfully synthesized and characterized. The experimental analysis and theoretical calculation demonstrate that the expanded facets spacing and oxygen vacancy of few-layered BiOI result in enhanced separation efficiency of photoinduced carriers and photon absorption efficiency. Therefore, few-layered BiOI shows much higher photocatalytic activity for CO2 conversion than that of bulk BiOI under visible or near-infrared (NIR) light. And the apparent quantum yields (AQY) are 0.14% and 0.02% for few-layered BiOI under 420 and 700 nm monochromatic light irradiation, respectively. These findings deep our understanding of few-layered BiOX (X=Cl,Br,I) photocatalysts, and propose a new route to design high efficient photocatalysts for energy and environmental photocatalysis.

We put forward an assessment system of thoracolumbar osteoporotic fracture (ASTLOF) evaluating the severity of thoracolumbar osteoporotic fracture. This study was to investigate its efficacy in guiding clinical practice.Three hundred and eighty-one patients with thoracolumbar vertebral osteoporosis fracture admitted to the hospital from January 2010 to December 2011 were enrolled in the study. All cases were evaluated by ASTLOF including evaluation of morphological changes, MRI, bone mineral density and pain. The patients were treated with different methods according to ASTLOF score. All patients were followed up on a regular basis. The treatment results were assessed by VAS and ODI.All patients were followed up with an average of 20.1 (range: 6-30) months. There were 91 cases of ASTLOF score4 points. Their average VAS score decreased from 8.0 ± 1.7 points to 2.0 ± 1.3 with statistical significance (P0.05) and the average ODI score decreased from 69.5 ± 2.8 to 38.1 ± 1.5 (P0.05). One hundred and thirty-two cases were with ASTLOF score=4, with the average VAS score decreased from 8.2 ± 1.4 to 1.9 ± 1.2 (P0.05) and the average ODI score decreased from 71.5 ± 3.7 to 36.2 ± 2.5 (P0.05). There were 158 cases of ASTLOF score ≥ 5, with the VAS score decreased from 8.0 ± 1.7 to 2.0 ± 1.3 and the ODI score decreased from 69.5 ± 2.8 to 38.1 ± 1.5.ASTLOF based on the severity of thoracolumbar osteoporotic fracture was suggested to be helpful in guiding clinical practice.

Some individuals could be quite cautious when making decisions and do not update their strategy frequently in the prisoner’s dilemma game. That is, instead of updating their strategy immediately after the game, they make decisions only after a certain period of deliberation. Moreover, individuals’ strategy update is based on the cumulative payoffs they got from their prior update. Since individuals in a group could be homogeneous or heterogeneous, their strategy can depend on two aspects: the initial time of the update and the length of its delay time. In this paper, three different cases that may lead to the delay of strategy update are taken into consideration. We find that introducing a deliberation mechanism can promote cooperation, that this effect could be greater when the delay time is extended, and that heterogeneity among individuals also has a positive effect on cooperation.

The objective of this study was to investigate the optimization and pathways of lignosulfonate biodegradation by a newly isolated lignin-degrading bacterial strain, Sphingobacterium sp. HY-H. The optimal conditions for lignosulfonate degradation capability were determined by Taguchi's orthogonal matrix method to be: initial pH, 7.0; temperature, 30 °C; and a lignosulfonate/nitrogen (as NH4Cl) mass ratio of 5. Under optimal conditions, the maximum lignosulfonate degradation capacity of strain HY-H was 31%. In order to characterize the changes in residual lignosulfonate and the metabolic products, FTIR spectra, functional groups, and elemental and GC–MS analysis were introduced. An examination of the data suggests a possible route of lignosulfonate degradation by strain HY-H was that lignosulfonate was first depolymerized to low-molecular-weight compounds; then the side chains of lignosulfonate were partially oxidized and further decarboxylated to produce carbon dioxide. If properly optimized and controlled, strain HY-H may play a role in the treatment of pulp and paper wastewater containing a high concentration of lignosulfonate, as well as in the lignocellulose breakdown for biofuel and chemicals production.

The electrocardiographic J wave, also referred as the Osborn wave, is a deflection with a dome or hump morphology at the junction between the QRS complex and the ST segment on the body surface ECG. Earlier studies attributed the J wave to a variety of factors including hypoxia, injury current, acidosis, delayed ventricular depolarization, and early ventricular repolarization.1 Clinical and arrhythmogenic significance of the J wave abnormalities had largely been ignored until 1996 when Yan and Antzelevitch published a study elucidating the ionic and cellular basis of the J wave, indicating that a prominent Ito-mediated action potential notch in ventricular epicardium but not endocardium may produce a transmural voltage gradient during early ventricular repolarization that could register as a J wave or J point elevation in the ECG.2 Growing evidence has since been advanced indicating that J wave abnormalities, which are often accompanied by early repolarization and ST segment elevation on the ECG, are in some cases associated with a risk of sudden cardiac death. The J wave syndromes, which represent a variable spectrum of phenotypic expression with accentuation of the J wave, can be inherited or acquired.3–6 This review attempts to summarize current knowledge about J-wave syndromes- linking bench work with the bedside.

The substrate bound heme-O 2 complexes (ferrous dioxygen, S4 and ferric peroxo, S5 ) of P450cam (CYP101) have been studied by combined quantum mechanical/molecular mechanical (QM/MM) calculations. The oxyheme (without side chains) is treated with density functional theory and the protein/solvent environment by the CHARMM22 force field. The B3LYP/CHARMM calculations are found to give reasonable descriptions of the oxyheme complexes. An open-shell singlet is predicted to be the ground state for S4 with small energy separations to the excited states. This result is consistent with previous experimental and QM studies. Comparisons with analogous calculations on the isolated QM system in the gas phase show that the protein/solvent environment reduces the open-shell singlet-quintet energy gap which should facilitate the spin inversion upon the binding of the atmospheric oxygen. An intact ferric peroxo complex S5 is found only in the doublet state whereas the quartet and sextet states dissociate upon QM/MM optimization (uncoupling).