255 research outputs found
文献目録
Confined
fluids such as oil and gas mixtures inside tight reservoirs
are systems that can experience high capillary pressure difference
between the liquid and gas phases. This capillary pressure difference
has an effect on the phase equilibrium and in some cases is considerably
high. We presented an algorithm which can reliably compute the whole
phase envelope for multicomponent mixtures when there is a capillary
pressure difference. It uses an equation of state for the phase equilibrium
and the Young–Laplace equation for the capillary pressure model.
The algorithm proves to be robust and efficient for test mixtures
with wide ranges of compositions at different capillary radii and
vapor fractions. The calculation results show that the phase envelope
changes everywhere except at the critical point. The bubble point
and the lower branch of the dew point show a decrease in the saturation
pressure, whereas the upper branch of the dew point shows an increase.
The cricondentherm is shifted to a higher temperature. We also presented
a mathematical analysis of the phase envelope shift due to capillary
pressure based on linear approximations. The resulting linear approximation
equations can predict the correct direction of the phase envelope
shift. Combined with the multicomponent Clapeyron equation, the equations
reveal why the shift changes direction for the saturation pressure
at the cricondentherm and for the saturation temperature at the cricondenbar.
The equations can be used to estimate the magnitude of shift, and
the approximation is close for the change in the bubble point pressure
Molecular Insights into Glyphosate Adsorption to Goethite Gained from ATR-FTIR, Two-Dimensional Correlation Spectroscopy, and DFT Study
Glyphosate
(PMG) complexation on iron (hydr)Âoxides impacts its
fate and transport in the environment. To decipher the molecular-level
interfacial configuration and reaction mechanism of PMG on iron (hydr)Âoxides,
the PMG protonation process, which influences the chemical and physical
properties of PMG, was first determined using ATR-FTIR spectroscopy.
The FTIR results reveal that the deprotonation occurs at carboxylate
oxygen when p<i>K</i><sub>a</sub><sub>1</sub>< pH <
p<i>K</i><sub>a</sub><sub>2</sub>, at phosphonate oxygen
when p<i>K</i><sub>a</sub><sub>2</sub>< pH < p<i>K</i><sub>a</sub><sub>3</sub>, and at amino nitrogen when pH
> p<i>K</i><sub>a</sub><sub>3</sub>. PMG complexation
on
goethite was investigated using in situ flow-cell ATR-FTIR, two-dimensional
correlation spectroscopy (2D-COS), and density functional theory (DFT)
calculations. The results indicate that the phosphonate group on PMG
interacts with goethite to form inner-sphere complexes with multiple
configurations depending on pH: binuclear bidentate (BB) and mononuclear
bidentate (MB) without proton under acidic conditions (pH 5), mononuclear
monodentate (MM) with proton and BB without proton at pH 6–8,
and MM without proton under alkaline conditions (pH 9). Phosphate
competition significantly impacted the PMG adsorption capacity and
its interfacial configurations. As a result, the stability of the
adsorbed PMG was impaired, as evidenced by its elevated leachability.
These results improve our understanding of PMG-mineral interactions
at the molecular level and have significant implications for risk
assessment for PMG and structural analog pollutants
Molecular Characterization of Barley 3H Semi-Dwarf Genes
<div><p>The barley chromosome 3H accommodates many semi-dwarfing genes. To characterize these genes, the two-rowed semi-dwarf Chinese barley landrace ‘TX9425’ was crossed with the Australian barley variety ‘Franklin’ to generate a doubled haploid (DH) population, and major QTLs controlling plant height have been identified in our previous study. The major QTL derived from ‘TX9425’ was targeted to investigate the allelism of the semi-dwarf gene <i>uzu</i> in barley. Twelve sets of near-isogenic lines and a large NILF<sub>2</sub> fine mapping population segregating only for the dwarfing gene from ‘TX9425’ were developed. The semi-dwarfing gene in ‘TX9425’ was located within a 2.8 cM region close to the centromere on chromosome 3H by fine mapping. Molecular cloning and sequence analyses showed that the ‘TX9425’-derived allele contained a single nucleotide substitution from A to G at position 2612 of the <i>HvBRI1</i> gene. This was apparently the same mutation as that reported in six-rowed <i>uzu</i> barley. Markers co-segregating with the QTL were developed from the sequence of the <i>HvBRI1</i> gene and were validated in the ‘TX9425’/‘Franklin’ DH population. The other major dwarfing QTL derived from the Franklin variety was distally located on chromosome 3HL and co-segregated with the <i>sdw</i>1 diagnostic marker <i>hv20ox2</i>. A third dwarfing gene, expressed only in winter-sown trials, was identified and located on chromosome 3HS. The effects and interactions of these dwarfing genes under different growing conditions are discussed. These results improve our understanding of the genetic mechanisms controlling semi-dwarf stature in barley and provide diagnostic markers for the selection of semi-dwarfness in barley breeding programs.</p></div
Blurred image restoration using knife-edge function and optimal window Wiener filtering
<div><p>Motion blur in images is usually modeled as the convolution of a point spread function (PSF) and the original image represented as pixel intensities. The knife-edge function can be used to model various types of motion-blurs, and hence it allows for the construction of a PSF and accurate estimation of the degradation function without knowledge of the specific degradation model. This paper addresses the problem of image restoration using a knife-edge function and optimal window Wiener filtering. In the proposed method, we first calculate the motion-blur parameters and construct the optimal window. Then, we use the detected knife-edge function to obtain the system degradation function. Finally, we perform Wiener filtering to obtain the restored image. Experiments show that the restored image has improved resolution and contrast parameters with clear details and no discernible ringing effects.</p></div
Adhesion of <i>Shewanella oneidensis</i> MR‑1 to Goethite: A Two-Dimensional Correlation Spectroscopic Study
Bacterial
adhesion to mineral surfaces is an important but underappreciated
process. To decipher the molecular level process and mechanism, the
adhesion of Shewanella oneidensis MR-1
cells to goethite was investigated using flow-cell attenuated total
reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy coupled
with two-dimensional correlation spectroscopy (2D-COS) analysis. The
FTIR results indicate that bacterial phosphate-moieties play an important
role in the formation of mono- and bidentate inner-sphere complexes,
whereas carboxylic groups on cell surface only have a minor contribution
to its adhesion. The 2D-COS analysis in short-term (0–120 min)
and long-term (2–18 h) stages reveal that the adhesion process
was in the following sequence: change in H-bonds of proteins on cell
surfaces > formation of monodentate inner-sphere surface complexes
> formation of outer-sphere surface complexes > transformation
of
protein secondary structure on cell surfaces > formation of additional
bridging bidentate surface complexes. In addition, the adhesion of
MR-1 cells on goethite was pH dependent due to pH impacts on the cell
structure and the interface charge. The in situ ATR-FTIR integrated
with 2D-COS analysis highlights its great potential in exploring complex
surface reactions with microbes involved. These results improve our
understanding of microbe–mineral interactions at the molecular
level and have significant implications for a series of biogeochemical
processes
The deblurred performances of different methods on the first test image.
<p>(a) The motion-blurred simulation image; (b) the final restoration result based on the proposed technique after edge correction; (c) the restoration result based on rectangular PSF; (d) the restoration result based on traditional Wiener filtering; (e) the restoration result based on traditional Lucy-Richardson; (f) the restoration result based on traditional Blind-deconvolution.</p
Phenotypes and height of the short-statured barley genotypes ‘TX9425’ and ‘Franklin’ grown under different temperature and day length conditions.
<p>(I) ‘TX9425’, grown in low temperatures and during short days; (II) ‘TX9425’, grown in warm temperatures and during long days; (III) ‘Franklin’, grown in low temperatures and during short days; and (IV) ‘Franklin’, grown in warm temperatures and during long days.</p
Fine mapping of the dwarfing locus derived from ‘TX9425’, a two-rowed Chinese landrace.
<p>The dwarfing gene was mapped to a 2.8 cM region, and was only 0.7 cM from the nearest marker, GBM1495.</p
Enrofloxacin Transformation on <i>Shewanella oneidensis</i> MR‑1 Reduced Goethite during Anaerobic–Aerobic Transition
Antibiotics
pollution has become a critical environmental issue
worldwide due to its high ecological risk. In this study, rapid degradation
of enrofloxacin (ENR) was observed on goethite in the presence of <i>Shewanella oneidensis</i> MR-1 during the transition from anaerobic
to aerobic conditions. The abiotic reactions also demonstrated that
over 70% with initial concentration of 10 mg L<sup>–1</sup> ENR was aerobically removed within 5 min by goethite with adsorbed
FeÂ(II), without especial irradiation and strong oxidants. The results
of spin trap electron spin resonance (ESR) experiments provide evidence
that FeÂ(II)/FeÂ(III) complexes facilitate the generation of •OH.
The electrophilic attack by •OH opens the quinolone ring of
ENR and initiates further transformation reactions. Five transformation
products were identified using high performance liquid chromatography-quadrupole
time-of-flight mass spectrometry and the ENR degradation process was
proposed accordingly. The identification of ENR transformation products
also revealed that both the surface adsorption and the electron density
distribution in the molecule determined the reactive site and transformation
pathway. This study highlights an important, but often underappreciated,
natural process for in situ degradation of antibiotics. With the easy
migration of the goethite-MR-1 complex to the anaerobic/aerobic interface,
the environmental fates of ENR and other antibiotics need to be seriously
reconsidered
The deblurred performances of different methods on the second test image.
<p>(a) The source image; (b) the motion-blurred simulation image; (c) the final restoration result based on the proposed technique; (d) the restoration result based on rectangular PSF; (e) the restoration result based on traditional Wiener filtering; (f) the restoration result based on traditional Lucy-Richardson; (g) the restoration result based on traditional Blind-deconvolution.</p
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