Throughout Silico Idea of Leaks in the structure Coefficients

A free volume theory of linear polyethylene (PE) melts [Soft Matter, 2019, 15, 9300-9309] was used to describe the crossover in the size dependence of the center-of-mass diffusion coefficients of ring PE melts from Dcm ∼ N-1.03±0.15 to Dcm ∼ N-1.88±0.14 at Nc ≈ 100. Parameters in the theory were determined theoretically by either the polymer reference interaction site model (PRISM) theory or molecular dynamics (MD) simulation data. The former method is computationally less expensive, whereas the latter gives more accurate results in calculating the temperature dependence of Dcm as different intermolecular and intramolecular potentials were explicitly included in the equation of motion. Both approaches were able to describe the dynamics below and above the crossover in the size dependence of Dcm.Potential energy landscape (PEL) concepts have been useful in conceptualizing the effects of intermolecular interactions on dynamic and thermodynamic properties of liquids and glasses. "Basins", or regions of reduced potential energy associated with locally preferred molecular packing are important PEL features. The molecular configurations at the bottom of these basins are referred to as inherent structures (ISs). Experimental methods for directly characterizing PEL features such as these are rare, largely relegating PEL concepts to theory and simulation studies, and impeding their exploration in real systems. Recently, we showed that quasielastic neutron scattering (QENS) data from propylene carbonate (PC) exhibit signatures of picosecond timescale motion that are consistent with intrabasin motion and interbasin transitions [Cicerone et al., J. Chem. Phys., 2017, 146, 054502]. Here we present optically-heterodyne-detected optical Kerr effect (OHD-OKE) spectroscopy studies on PC. The data exhibit signatures of motion within and transitions between basins that agree quantitatively with and extend the QENS results. We show that the librational component of the OKE response corresponds to intrabasin dynamics, and the enigmatic intermediate OKE response corresponds to interbasin transition events. The OKE data extend the measurement range of these parameters and reveal their utility in characterizing PEL features of real systems.An interesting chemiluminescence (CL) phenomenon of cyclic peroxides originating from tetrahydrofuran hydrogen peroxide (THF-HPO) in the presence of BSA-stabilized Au NCs (Au@BSA NCs) was found for the first time. In this CL system, Au@BSA NCs can greatly accelerate the decomposition of THF-HPO, and then chemiluminescence resonance energy transfer (CRET) occurs between excited dioxetane derivatives and the Au@BSA NCs, yielding enhanced CL emission which can be further enhanced more than 10 times by the addition of copper ions. Based on this, a synergistic CL nanoprobe with a special signal amplification strategy was developed.Hybrid capacitive deionization (HCDI) has emerged as a promising desalination technique due to its ultra-high salt removal capacity in high brine water. However, the mechanism behind HCDI is seldom discussed anywhere. Herein, we perform a comprehensive investigation to have some insight into the HCDI behavior of NaxCoO2 by varying x as 0.2, 0.5, 0.7, 1.0 and 1.6. Regardless of x, NaxCoO2 are classified as a representative P63/mmc space group with a P2 layered structure. With the increase of the sodium content, the (002) crystal plane of NaxCoO2 shifts significantly toward a high angle as the distance between CoO2 layers decreases. This results from the variation of the Na-O bonding length as well as the bonding energy according to the first-principles simulation. Moreover, it is observed that the Na-O bond broke once the input energy is higher than the Na-O bonding energy, leading to the electrochemical pre-activation of NaxCoO2. As a result, Na0.7CoO2 exhibits the best HCDI performance, i.e. NIK SMI1 molecular weight a salt removal capacity of 63.0 mg g-1 and a charge efficiency of 97% in NaCl solutions with an initial conductivity of 2000 μS cm-1. Besides, the intercalation of sodium ions into NaxCoO2 has been confirmed by differentiating the respective contributions of pseudo-capacitance together with crystal phase transformation. Our results show that the desalination behavior of NaxCoO2 can be mediated by controlling the sodium content and electrochemical pre-activation.Light-sensitive Ca2+-regulated photoprotein berovin is responsible for the bioluminescence of the ctenophore Beroe abyssicola. It shares many properties of hydromedusan photoproteins although the degree of identity of its amino acid sequence with those of photoproteins is low. There is a hydrogen bond between C-terminal Pro and Arg situated in the N-terminal α-helix of hydromedusan photoproteins that supports a closed conformation of the internal cavity of the photoprotein molecule with bound 2-hydroperoxycoelenterazine. The C- and N-terminal hydrogen bond network is necessary to properly isolate the photoprotein active site from the solvent and consequently to provide a high quantum yield of the bioluminescence reaction. In order to find out which berovin residues perform the same function we modified the N- and C-termini of the protein by replacing or deleting various amino acid residues. The studies on berovin mutants showed that the interaction between C-terminal Tyr208 and Tyr13 localized in the first α-helix of the photoprotein is important for the stabilization and proper orientation of the oxygenated coelenterazine adduct within the internal cavity as well as for supporting the closed photoprotein conformation. We also suggest that the interplay between Tyr residues in ctenophore photoproteins occurs rather through the π-π interaction of their phenyl rings than through hydrogen bonds as in hydromedusan photoproteins.Inorganic/organic double network (DN) ion gels, which are composed of an inorganic silica particle network, an organic poly(N,N-dimethylacrylamide) (PDMAAm) network, and a large amount of ionic liquid, showed excellent mechanical strength of over 25 MPa compression fracture stress at an 80 wt% ionic liquid content. The excellent mechanical strength of these inorganic/organic DN ion gels was attributed to the energy dissipation of the inorganic/organic DN structure. It has been considered that the energy dissipation in inorganic/organic DN ion gels is caused by the internal fracture of the silica particle network, which is preferentially fractured by deformation. However, no studies aiming to investigate the internal fracture of the silica particle network in inorganic/organic DN ion gels have been conducted by direct approaches. In this study, the internal fracture of the silica particle network in the inorganic/organic DN ion gel was directly evaluated by a small angle X-ray scattering (SAXS) technique. The synchrotron SAXS measurements conducted under a uniaxial loading-unloading process demonstrated that the aggregation size of the silica particle network irreversibly decreased with uniaxial stretch.