Adsorption and Reaction Branching of Molecular Carbonates on Lithiated C(0001) Substrates

The desorption and interactions of ethylene carbonate (EC) and dimethyl carbonate (DMC) with clean and lithiated graphite substrates were measured by temperature-programmed desorption (TPD) and reaction (TPR) methods under UHV conditions. Both EC and DMC interact weakly with the clean C(0001) surface with adsorption energies of 0.60 ± 0.06 and 0.64 ± 0.05 eV, respectively. Addition of Li⁺ to the C(0001) substrate significantly increases the binding energies of molecular carbonates, and the range of measured values is indicative of EC solvation of lithium ions. EC undergoes complete decomposition on metallic Li films. Organolithium products were quantified by TPR, and the amount of lithium carbonate product was determined by detailed mass balance analysis. Decomposition of 1.5 L of EC resulted in the formation of 0.64 ± 0.12 L of lithium ethylene dicarbonate, 0.40 ± 0.05 L of lithium ethylene glycolate, and 0.5 ± 0.2 L of lithium carbonate. The branching ratio at the immediate EC–metallic lithium interface was determined as 70.% organolithium products vs 30% inorganic lithium product

Born–Haber Cycle for Monolayer Self-Assembly at the Liquid–Solid Interface: Assessing the Enthalpic Driving Force

The driving force for self-assembly is the associated gain in free energy with decisive contributions from both enthalpy and entropy differences between final and initial state. For monolayer self-assembly at the liquid–solid interface, solute molecules are initially dissolved in the liquid phase and then become incorporated into an adsorbed monolayer. In this work, we present an adapted Born–Haber cycle for obtaining precise enthalpy values for self-assembly at the liquid–solid interface, a key ingredient for a profound thermodynamic understanding of this process. By choosing terephthalic acid as a model system, it is demonstrated that all required enthalpy differences between well-defined reference states can be independently and consistently assessed by both experimental and theoretical methods, giving in the end a reliable value of the overall enthalpy gain for self-assembly of interfacial monolayers. A quantitative comparison of enthalpy gain and entropy cost reveals essential contributions from solvation and dewetting, which lower the entropic cost and render monolayer self-assembly a thermodynamically favored process

Characterizing the Interactions of Dimethyl Sulfoxide with Water: A Rotational Spectroscopy Study

The interaction of dimethyl sulfoxide with water has been investigated by Fourier-transform microwave spectroscopy of the 1:1 complex and its isotopologues, complemented with quantum chemical calculations. The rotational spectra of 34S and 13C isotopologues in natural abundance and the H218O and deuterated water enriched isotopologues have been measured, allowing a partial structure determination and establishing the position of water in the complex. In the most stable conformation water was found to be the donor of a primary OH···OS bond to the oxygen atom of dimethyl sulfoxide and acceptor of two weak CH···OH bonds with the methyl hydrogen atoms of dimethyl sulfoxide. From the structural determination confirmed by quantum chemical calculations, the water molecule lies in the symmetry plane of dimethyl sulfoxide, and the complex has an overall Cs symmetry. The experimental findings are supported by atoms in molecules and symmetry-adapted perturbation theories, which allowed for determining the hydrogen bond and intermolecular interaction energies, respectively

Solvent-Dependent Stabilization of Metastable Monolayer Polymorphs at the Liquid–Solid Interface

Self-assembly of 1,3,5-tris(4′-biphenyl-4″-carbonitrile)benzene monolayers was studied at the liquid–solid interface by scanning tunneling microscopy. Application of different fatty acid homologues as solvents revealed a solvent-induced polymorphism. Yet, tempering triggered irreversible phase transitions of the initially self-assembled monolayers, thereby indicating their metastability. Interestingly, in either case, the same thermodynamically more stable and more densely packed monolayer polymorph was obtained after thermal treatment, irrespective of the initial structure. Again, the same densely packed structure was obtained in complementary solvent-free experiments conducted under ultrahigh vacuum conditions. Thus, self-assembly of metastable polymorphs at room temperature is explained by adsorption of partially solvated species under kinetic control. The irreversible phase transitions are induced by thermal desolvation, that is, desorption of coadsorbed solvent molecules

Data_Sheet_1_Enhancement effects of mangrove restoration on blue carbon storage in Qinzhou Bay.doc

IntroductionMangroves are the main carbon sinks in tropical regions and have high capabilities for carbon sequestration. Protection and restoration of mangroves are necessary to reduce carbon emissions and fight climate change. While the Qinzhou Bay as the main area of national mangrove restoration plan in the future, studies on its carbon pools, especially assessment of the carbon sink enhancement effect of restored mangroves along forest chronosequence, are lacking.MethodsThis study aimed to quantify the changes in restored mangrove soil carbon stock, vegetation and root carbon stocks along the forest age sequence in Qinzhou Bay through field survey.ResultsThe results revealed that the carbon stocks of vegetation and roots significantly increased with the developing forest age. Only in the soil layer above 30 cm, the soil carbon storage apparently increased with the developing forest age in non-cofferdam area, and then decreased slowly after reaching the peak (at 6 ~ 8 years). Moreover, the soil carbon storage of mangroves was greater in the cofferdam area than in the non-cofferdam area.DiscussionThis implied that the cofferdam restoration efforts may be more effective in enhancing blue carbon storage, during the initial stages of the restoration process. The results of this study suggested that mangrove restoration has substantial potential capacity in carbon storage and nutrient cycling, providing a reference for the protection and restoration efforts concerning mangroves.</p

Size-Tunable and Monodisperse Tm³⁺/Gd³⁺-Doped Hexagonal NaYbF₄ Nanoparticles with Engineered Efficient Near Infrared-to-Near Infrared Upconversion for In Vivo Imaging

Hexagonal NaYbF₄:Tm³⁺ upconversion nanoparticles hold promise for use in high contrast near-infrared-to-near-infrared (NIR-to-NIR) in vitro and in vivo bioimaging. However, significant hurdles remain in their preparation and control of their morphology and size, as well as in enhancement of their upconversion efficiency. Here, we describe a systematic approach to produce highly controlled hexagonal NaYbF₄:Tm³⁺ nanoparticles with superior upconversion. We found that doping appropriate concentrations of trivalent gadolinium (Gd³⁺) can convert NaYbF₄:Tm³⁺ 0.5% nanoparticles with cubic phase and irregular shape into highly monodisperse NaYbF₄:Tm³⁺ 0.5% nanoplates or nanospheres in a pure hexagonal-phase and of tunable size. The intensity and the lifetime of the upconverted NIR luminescence at 800 nm exhibit a direct dependence on the size distribution of the resulting nanoparticles, being ascribed to the varied surface-to-volume ratios determined by the different nanoparticle size. Epitaxial growth of a thin NaYF₄ shell layer of ∼2 nm on the ∼22 nm core of hexagonal NaYbF₄:Gd³⁺ 30%/Tm³⁺ 0.5% nanoparticles resulted in a dramatic 350 fold NIR upconversion efficiency enhancement, because of effective suppression of surface-related quenching mechanisms. In vivo NIR-to-NIR upconversion imaging was demonstrated using a dispersion of phospholipid-polyethylene glycol (DSPE-PEG)-coated core/shell nanoparticles in phosphate buffered saline

Evolution of Spinel LiMn₂O₄ Single Crystal Morphology Induced by the Li₂MnO₃ Phase during Sintering

The most severe problems for adoption of LiMn2O4 (LMO) as a low-cost and sustainable cathode in lithium-ion batteries are manganese dissolution and structural degradation, especially at an elevated temperature. Developing large single crystals (SCs) for LMO could be a feasible solution since it significantly reduces electrode/electrolyte interfaces where degradation can occur, while exceptionally high ionic diffusivity of its spinel structure could guarantee decent kinetics. In this work, we discovered a unique correlation between morphology and synthesis conditions, especially oxygen partial pressure in a successful development of defect-free faceted LMO SCs. Further experimental and theoretical studies identified that crystal growth of spinel LMO can be dramatically promoted by the Li2MnO3 impurity, which is spontaneously generated at low oxygen partial pressure during high temperature synthesis. Meanwhile, electrochemical performances were found to be controlled by both impurity and crystallite size. We believe that with more understanding of synthesis parameters, LMO single crystals could achieve optimal electrochemical performance

Large Area Synthesis of a Nanoporous Two-Dimensional Polymer at the Air/Water Interface

We present the synthesis of a two-dimensional polymer at the air/water interface and its nm-resolution imaging. Trigonal star, amphiphilic monomers bearing three anthraceno groups on a central triptycene core are confined at the air/water interface. Compression followed by photopolymerization on the interface provides the two-dimensional polymer. Analysis by scanning tunneling microscopy suggests that the polymer is periodic with ultrahigh pore density

Biometrical parameters of individual QTL affecting growth traits and sex of half-smooth tongue sole.

<p>R² (%): proportion of the explained phenotypic variance.</p><p>LG: linkage group.</p

Construction of a High-Density Microsatellite Genetic Linkage Map and Mapping of Sexual and Growth-Related Traits in Half-Smooth Tongue Sole (<em>Cynoglossus semilaevis</em>)

<div><p>High-density genetic linkage maps of half-smooth tongue sole were developed with 1007 microsatellite markers, two SCAR markers and an F1 family containing 94. The female map was composed of 828 markers in 21 linkage groups, covering a total of 1447.3 cM, with an average interval 1.83 cM between markers. The male map consisted of 794 markers in 21 linkage groups, spanning 1497.5 cM, with an average interval of 1.96 cM. The female and male maps had 812 and 785 unique positions, respectively. The genome length of half-smooth tongue sole was estimated to be 1527.7 cM for the females and 1582.1 cM for the males. Based on estimations of the map lengths, the female and male maps covered 94.74 and 94.65% of the genome, respectively. The consensus map was composed of 1007 microsatellite markers and two SCAR markers in 21 linkage groups, covering a total of 1624 cM with an average interval of 1.67 cM. Furthermore, 159 sex-linked SSR markers were identified. Five sex-linked microsatellite markers were confirmed in their association with sex in a large number of individuals selected from different families. These sex-linked markers were mapped on the female map LG1f with zero recombination. Two QTLs that were identified for body weight, designated as We-1 and We-2, accounted for 26.39% and 10.60% of the phenotypic variation. Two QTLs for body width, designated Wi-1 and Wi-2, were mapped in LG4f and accounted for 14.33% and 12.83% of the phenotypic variation, respectively. Seven sex-related loci were mapped in LG1f, LG14f and LG1m by CIM, accounting for 12.5–25.2% of the trait variation. The results should prove to be very useful for improving growth traits using molecular MAS.</p> </div