Belyakov, Alexander V.Vogt, NataljaDemaison, Jean A.Kulishenko, Roman Yu....
5页
查看更多>>摘要：The semiexperimental equilibrium molecular structure (r(s)(ee)) of the title compound is derived from the experimental rotational constants of the parent molecule and a number of isotopologues using a quantum-chemical force field. The quadratic and cubic force fields are calculated at the B2PLYP double hybrid functional with the correlation-consistent triple-zeta cc-pVTZ basis set. The rovibrational and electronic corrections necessary for transformation of ground-state rotational constants to equilibrium ones are calculated using anharmonic (cubic) force constants and rotational g tensor, respectively. The r(s)(ee) structure is used to benchmark the results of coupled-cluster computations (CCSD(T)).
查看更多>>摘要：Zn1-x(Co, Fe)(x)O nanoparticles (NPs) were synthesized by sol-gel combustion method. XRD pattern confirmed the formation of single-phase hexagonal (wurtzite) structure in all samples with P63mc space group. The average crystallite sizes varied between 20 and 28 nm. All samples were optically activated under ultraviolet light. The optical band gap values varied between 3.33 and 3.82 eV. The PL study revealed the reduction of the recombination of charge carriers due to (Co, Fe) co-doping into ZnO. Enhancement of the antibacterial activity was observed due to (Co, Fe) co-doping. Zn0.95Co0.025Fe0.025 NPs exhibited excellent antibacterial activity against E. coli and S. aureus bacteria.
Garcia-Contreras, M. A.Palomino-Asencio, L.Catarino-Centeno, R.Garcia-Hernandez, E....
6页
查看更多>>摘要：& nbsp;Ab initio simulations were performed to evaluate the use of pristine and BN-doped carbon nanocones as adsorption platforms or sensors of harmful gases CO, CO2, and NO2. The proposed models show good interaction energies, in the range of physisorption and chemisorption. Furthermore, the electronic properties and short recovery times, make the systems proposed (except the CNCB-NO2) good candidates for sensing or adsorption platforms of CO, CO2, and NO2.
查看更多>>摘要：This study aims to apply thermogravimetric analysis technology to develop a facile way for long-term stability prediction of polyacrylamide-type polymers at high temperature and high salinity reservoir conditions, to maintain sufficient viscosity in chemical flooding. Pyrolysis behaviors in powder form and long-term stability in solution of nine polyacrylamide-type polymers were investigated. Activation energies of polymers determined by Coats-Redfern model were correlated with half-life from viscosity measurements to estimate stability at harsh conditions. Moreover, decomposition rates of polymer molecular weight present good correlations with halflives, and activation energies respectively, which indicates molecular weight reduction results in solution viscosity loss.
Micikas, Robert J.Acharyya, ArushaSmith, Amos B., IIIGai, Feng...
7页
查看更多>>摘要：We synthesize N alpha-Boc-4-dicyanovinyltryptophan OMe (4DCV-Trp) and characterize its photophysical properties in different solvents. We find that the maximum absorption wavelength of 4DCV-Trp is at ca. 430 nm in water, and that its fluorescence spectrum exhibits a large Stokes shift (e.g., ca. 150 nm in water). Furthermore, solventdependent studies reveal a positive, linear correlation between the frequency of 4DCV-Trp's fluorescence maximum and the solvent polarity index, suggesting that 4DCV-Trp could serve as a polarity reporter of proteins. In addition, we synthesize 4-nitrotryptophan and validate its utility as a fluorescence quencher of a blue fluorescent amino acid, 4-cyanotryptophan.
查看更多>>摘要：Temperature-induced bandshift of luminescence peaks is frequently described with McCumber-Sturge relation which is difficult for fitting or practical applications due to its mathematical complexity. Here for the first time, we give its exact solution in terms of polylogarithms, and an excellent approximation that is better at lower temperatures than the approximation by Walsh and Di Bartolo (WB). The novel approximation is analytically compared with that of WB, clearly giving the preferred temperature and Debye temperature ranges for each approximation. Three additional approximations are given, each with lowered complexity, until the equivalent quadratic form of Magomedov's approximation is reached. All approximations are compared for their complexity vs applicable temperature range.
查看更多>>摘要：We study the PVT properties and diffusion characteristics of H2O/H-2/CO2 mixtures confined in graphite nanoslits via molecular dynamics simulations. The results show that the pressure decreases with increasing molar volume and increases with increasing slit-width except for the narrow width d = 6 angstrom due to the dominating repulsive surface forces. Diffusion coefficients of components increase with increasing molar volume or slit-width, and increase with increasing temperature except for H-2 owing to competitive adsorption. Moreover, H2O component with the highest mole fraction plays a major role in capillary condensation that enhances the ability of H2O molecules of forming tetrahedral structures.
查看更多>>摘要：We have shown that electrons (1.0 keV) scattered by Ar in a monocycle THz-wave (0.6 THz) field gain and lose their energy through the THz-wave assisted electron scattering (TAES) and that the magnitude of the energy gain and loss reaches the energy of as many as ~ 800 photons of the THz-wave, exhibiting the extremely high-order energy exchanges. We have also shown that observed characteristic asymmetries in the azimuthal-angle dependence of the energy spectra of TAES signals are reproduced well quantitatively by the theoretical TAES signals calculated using the modified Kroll-Watson formula and the experimentally determined THz-wave form.
查看更多>>摘要：& nbsp;The biosynthesis of silver nanoparticles have received great attention in the field of nanotechnology because of its antimicrobial and biomedical applications. In the current research scenario, the green synthesis of metal nanoparticles is expected to be cost-effective and environmentally benign alternative. In this effort, the fruit extracts from the Syzygium cumini was used as the reducing agent to synthesize silver nanoparticles (AgNPs) and the antioxidant, antibacterial, and anti-inflammatory properties of the synthesized nanoparticles have been evaluated. The synthesized Ag nanoparticles were characterized by UV-Visible spectroscopy (UV), Fourier-transform infrared spectroscopy (FTIR), Powder X-ray Diffraction (XRD) and scanning electron microscope (SEM).The formation of silver nanoparticles was confirmed by optical performance i.e change in color using UV-Visible spectroscopy showing a characteristic peak of silver nanoparticles at 443 nm. The presence of OH and C=O of plant secondary metabolites of Syzygium cumini were confirmed by FTIR spectroscopy, liable for capping and reduction of metal nanoparticles surface. Powder XRD analysis was used to analyze the crystal structure. This medicinal plant extract mediating green biosynthesized silver nanoparticles exhibited good in vitro-antioxidant, antibacterial and anti-inflammatory activities. Therefore, results of the present study highlights the synthesis of cost-effective, eco-friendly drugs with less side effects, which showed that there is the urge of in vivo studies at a molecular level to develop silver nanoparticles through greener approach using the medicinal plant (Syzygium cumini) extract as antibacterial, antioxidant, and anti-inflammatory agent for the treatment of bacterial infection, inflammation and many free radical oriented diseases.
查看更多>>摘要：We obtained temperature dependence up to 150 ?C of the triplet positronium (ortho-Ps) lifetime in N,N,N-Trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide (TMPA-TFSI) using the vertical slow positron beamline installed at AIST. The ortho-Ps lifetimes at the near-surface and bulk regions of TMPA-TFSI were measured. The lifetime difference between the near-surface and bulk at 150 ?C, 130 ?C above the melting temperature, suggested that the molecular oriented structure at the surface remained. The ortho-Ps lifetimes at the near-surface and bulk became shorter as the temperature increased. On the contrary, the ortho-Ps lifetimes became longer as the temperature increased when other molecular liquids were employed except for water.
NSTL
Elsevier