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关键词： Nitrogen deposition   Plant biomass   Plant richness   Plant-soil-microbe interactions   Soil microbial respiration   Soil physicochemical properties  

摘要： Rapidly increasing atmospheric nitrogen (N) deposition may affect plants, microbes, and their interactions by changing soil physicochemical properties. A few studies have explored how the integrated plant-soil-microbe system responds to elevated N deposition;however, the experimental N loads used in these studies are generally higher than current and future N deposition rates. Thus, these results could generate highly uncertain predictions of the plant-soil-microbe system in response to N deposition because high N addition levels always trigger environmental stress (e.g., soil acidification). We manipulated a long-term experiment, consisting of six N addition levels (0, 1.15, 2.30, 4.60, 9.20, and 13.80 g N m⁻² yr⁻¹), in a semiarid grassland in northern China. Our results showed that N addition caused a significant negative relationship between dissolved organic carbon (DOC) and inorganic N, indicating that N addition enhanced C limitation of the soil microbial community and this effect triggered significant decreases microbial respiration. We also demonstrated that N addition significantly decreased soil fungal richness but had no effect on soil bacterial richness. Additionally, aboveground and belowground biomass were significantly increased with N addition, with the highest value at 9.20 N m⁻² yr⁻¹ treatment. Relative to control treatment, plant richness was not significantly changed when the N addition rates were lower than 4.6 g N m⁻² yr⁻¹ but then significantly decreased. Reduced plant richness and soil microbial respiration were associated with the changes in dissolved inorganic nutrients, soil total nutrients, DOC, as well as soil water content rather than dissolved organic phosphorus and pH. Importantly, aboveground biomass presented a significant negative effect on plant richness, whereas this effect was positive via the pathway of soil microbial respiration. These results show that the curr

关键词： Post-translational modifications   Phosphorylated proteins   Evolutionary information   Physiochemical properties   Support vector machine   Local fisher discrimination analysis  

摘要： Protein phosphorylation is an emerging post-translational modification, which critically involved in the introcellular process of the human body by controlling diverse functions ranging from cell growth to metabolism. The existing experimental methods for identifying phosphorylated proteins are overpriced and resource-intensive;thus, it is necessary to develop a fast and accurate computational method to address the problem. Here we report a novel predictor HPhosPPred, a phosphorylated protein prediction method that is incorporating highly discriminative evolutionary and physicochemical information conserved in protein primary motifs, namely pseudo-position specific scoring matrix, the auto-covariance transformation of the position-specific scoring matrix and normalized moreau-broto auto-correlation. Further, to boost up the generalization capability of HPhosPPred, we used local fisher discriminant analysis as a dominant feature selection strategy for eliminating redundant and noise patterns from the extracted features. Finally, the optimized features feed to support vector machine with radial basis function kernel to predict phosphorylated proteins. As evident from the results, the proposed method achieved promising performance with an accuracy of 80.68%, sensitivity of 84.63%, specificity of 73.67%, and Matthew's correlation coefficient of 0.581 using rigorous leave-one-out-cross-validation test and 10-fold cross-validation test. The empirical outcomes demonstrate that the developed model outperformed the existing stateof-the-art methods. Furthermore, our analysis reveals that the proposed tool can help detect unseen phosphorylated proteins in particular and proteomics research in general. The source code and dataset are publicly available at https://***/saeed344/HPhosPPred.

关键词： Aniline   Molecular interaction   Ultrasonic velocity   Physico-chemical parameter   Butanol  

摘要： The possibility of azeotrope formation between a butanol isomer, toluene with aniline is studied by examining the relative volatility calculation for all the six binary mixtures at the considered mole fractions. The study is carried out through density, viscosity and ultrasonic velocity measurements. Thermo-acoustical parameters such as molar volume, adiabatic compressibility, free length, free volume, internal pressure and their excess values are obtained from the experimental study for all the mixtures with a view to investigate the exact nature of molecular interaction. For this, the necessary standard values of the individual components are included. The nature of the existence of the suggested interaction is found to be useful in predicting the azeotropic formation and determining the exact mole fraction of such formations. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Cellulose  

摘要： The substantial part of the water-soluble hemicellulose fraction, obtained when processing cellulose to produce paper and other products, has so far been discarded. The aim of this work is to reveal the interfacial properties of softwood hemicellulose (galactoglucomannan, GGM) in relation to their molecular and solution structure. In this study the sugar composition of GGM was characterised by chemical analysis as well as 1D and 2D NMR spectroscopy. Previously it has been demonstrated that hemicellulose has high affinity towards cellulose and has the ability to alter the properties of cellulose based products. This study is focused on the interactions between hemicellulose and the cellulose surface. Therefore, adsorption to hydrophobized silica and cellulose surfaces of two softwood hemicellulose samples and structurally similar seed hemicelluloses (galactomannans, GMs) was studied with ellipsometry, QCM-D and neutron reflectometry. Aqueous solutions of all samples were characterized with light scattering to determine how the degree of side-group substitution and molecular weight affect the conformation and aggregation of these polymers in the bulk. In addition, hemicellulose samples were studied with SAXS to investigate backbone flexibility. Light scattering results indicated that GM polymers form globular particles while GGMs were found to form rod-like aggregates in the solution. The polysaccharides exhibit higher adsorption to cellulose than on hydrophobic surfaces. A clear correlation between the increase in molecular weight of polysaccharides and increasing adsorbed amount on cellulose was observed, while the adsorbed amount on the hydrophobic surface was fairly independent of the molecular weight. The obtained layer thickness was compared with bulk scattering data and the results indicated flat conformation of the polysaccharides on the surface.

关键词： Thick films  

摘要： Chemical solution deposition (CSD) of epitaxial YBa2Cu3O7(YBCO) films is a high throughput, cost-effective approach to grow high critical current superconducting conductors for power applications. Achieving high critical currents requires to grow epitaxial films with large thicknesses and this is still an open issue in CSD. Metalorganic precursor solution deposition can be tailored to achieve high film thicknesses, however, the pyrolysis step may heavily compromise the film quality due to the in-plane stress generated by a strong film shrinkage. Here, we disclose the complex relationship existing during the pyrolysis process between the physico-chemical transformations and the microstructure of the films. A low-fluorine trifluoroacetate (TFA) and propionate (prop) route to YBCO films with a final thicknesses in the range of 700-800 nm was studied to understand the phenomena. Morphological analysis byin situoptical microscopy video imaging under specific heating rates allowed to identify the thermokinetic conditions leading to permanent or reversible wrinkling and crack formation. The origin of the microstructural transformations during the pyrolysis of thick films has been disentangled through parallelin situanalyses of the chemical, thermal and mechanical properties, together with film thickness measurements. A key finding has been the identification of an intermediate liquid phase relieving the compressive stress responsible of wrinkling. Disclosing the origin of the physico-chemical transformations opens the path towards defining optimized pyrolysis processing conditions for high quality single deposition of CSD films.

摘要： The foreword to this special issue of the Journal provides an overview of the papers that have been contributed by participants at the 2019 RACI Australian Conference on Physical Chemistry, which was held at the University of Western Australia from 11 to 14 February 2019. [ABSTRACT FROM AUTHOR]

关键词： Cellulose acetate propionate   injection   lactic acid   mechanical properties   melt viscosity  

摘要： Cellulose acetate has a high melting temperature due to intense intermolecular hydrogen bonding and is not significantly different from the deterioration temperature, so decomposition may occur during processing. Generally, in order to prevent pyrolysis of CA in the melting process, it is dissolved by using a solvent such as CS2 or H2SO4. However, it is not suitable for extrusion and injection process, and plasticized CA composition is prepared using plasticizer. In general, Dioctyl phthalate (DOP) is the most widely used plasticizer, and polyethylene glycol (PEG), glycerin (GC) triacetin (TA) and the like are partly used as environmentally friendly plasticizers. In this study, lactic acid was used as a compatibilizer and viscosity modifier in addition to plasticizer to prepare a composite. When the content of lactic acid is 5 wt% or more, phase separation occurs, so that the viscosity of the composition is controlled by blending in the range of 1 similar to 5 wt%. The melting characteristics of the prepared compositions were confirmed by DSC and TGA, and specimens were prepared by injection molding. The effect of lactic acid content on the melt viscosity was measured and the yield stress, yield strain and elastic modulus were calculated by the evaluation of tensile properties. The composition of this study showed a viscosity change of about 10 similar to 50% compared with the conventional one and the thermal properties were also different. The thermal properties were also different. In addition, the change of mechanical strength was observed depending on the degree of commercialization of additives.

关键词： Interfaces   Metals   Electrodes   Lithium   Stability  

摘要： Developing reversible lithium metal anodes with high rate capability is one of the central aims of current battery research. Lithium metal anodes are not only required for the development of innovative cell concepts such as lithium-air or lithium-sulfur batteries, they can also increase the energy density of batteries with intercalation-type cathodes. The use of solid electrolyte separators is especially promising to develop well-performing lithium metal anodes, because they can act as a mechanical barrier to avoid unwanted dendritic growth of lithium through the cell. However, inhomogeneous electrodeposition and contact loss often hinder the application of a lithium metal anode in solid-state batteries. In this review, we assess the physicochemical concepts that describe the fundamental mechanisms governing lithium metal anode performance in combination with inorganic solid electrolytes. In particular, our discussion of kinetic rate limitations and morphological stability intends to stimulate further progress in the field of lithium metal anodes.

关键词： Salts   Anions   Organic polymers   Solvents   Differential scanning calorimetry  

摘要： We investigated the influence of anion type (salicylate, [(MOB)MIm][Sal], vs chloride, [(MOB)MIm][Cl]) of imidazolium- based ionic liquid (IL) and its content on the curing kinetics of bisphenol A diglicydyl ether (DGEBA of molecular weight M-n = 340 g/mol). Further physicochemical properties (i.e., glass transition temperature, T-g, and conductivity, sigma(dc)) of produced polymers were investigated. The polymerization of the studied systems was examined at various molar ratios (1:1, 10:1, and 20:1) at different reaction temperatures (T-reaction = 353-383 K) by using differential scanning calorimetry (DSC). Interestingly, both DGEBA/IL compositions studied herein revealed significantly different reaction kinetics and yielded materials of completely distinct physical properties. Surprisingly, in contrast to [(MOB)MIm][Cl], for the low concentration of [(MOB)MIm] [Sal] in the reaction mixture, an additional step in the kinetic curves, likely due to the combined enhanced initiation activity of anion (salicylate)-cation (imidazolium-based), was noted. To thoroughly analyze the kinetics of all studied systems, including the two-step kinetics of DGEBA/[(MOB)MIm] [Sal], we applied a new approach that relies on the combination of the two phenomenological Avrami equations. Analysis of the determined constant rates revealed that the reaction occurring in the presence of the salicylate anion is characterized by higher activation energy with respect to those with the chloride. Moreover, DGEBA/[(MOB)MIm][Sal] cured materials have higher T g in comparison to DGEBA polymerized with [(MOB)MIm][Cl] independent of the IL concentration. This fact might indicate that, most likely, the products of hardening are highly cross-linked (high T-g) or oligomeric linear polymers (low T-g) in the former and latter cases, respectively. Such a change in the chemical structure of the polymer is also reflected in the dc conductivity measured at the glass transition temperature, which is much higher

关键词： Japaratuba river basin   Total petroleum hydrocarbons (TPH)   Physicochemical analyses   Onshore oil fields   Hydrogeology  

摘要： The Japaratuba River Basin is one of the most important hydrogeological units in terms of water demand in the state of Sergipe, Brazil. Due to its poorly developed water supply plan, oil exploration and agricultural industries, the Japaratuba River Basin is susceptible to considerable environmental stress. Emphasis is given to the area of the Campo de Carmopolis which, being the largest onshore oil field in Brazil, represents the greatest agent of environmental pollution in the area. The aim of this study is to characterise the contaminants present in surface water and groundwater of the southern part of Japaratuba River Basin region which is proximal to Carmopolis Oil field. We performed physicochemical and total petroleum hydrocarbons (TPH) analyses in ten water samples from the southernmost part of the basin. To better characterise the hydrogeological systems, 27 physicochemical parameters were analysed: potential of hydrogen (pH), colour, turbidity, electrical conductivity (EC), hardness, acidity, alkalinity, iron (Fe), nitrate (NO3-), nitrite (NO2-), ammonia (NH3), chloride (Cl-), phosphorus (P), fluoride (F-), sulphate (SO42-), bromate (BrO3-), calcium (Ca2+), magnesium (Mg2+), potassium (K+), sodium (Na+) bicarbonate (HCO3-), carbonate (CO32-), aluminium (Al3+), manganese (Mn2+), total dissolved solids (TDS), chlorite (ClO2-) and glyphosate. The results identified concentrations above Brazil's maximum permitted value (MPV) for TPH in two samples, and at least four samples presented values that do not meet the potability standards established by Brazilian federal legislation (Portaria de Consolidacao No 5, 2017). This enforces the need for more robust remediation and mitigation methods on the contaminated sites, since the local population relies solely on these water resources and poor management would lead to health hazards and socioeconomic impacts. Continuous monitoring of sampled locations along with an increase in sampling mesh are also recommended.