Wave packet dynamics of potassium dimers attached to helium nanodroplets

The dynamics of vibrational wave packets excited in K$_2$ dimers attached to superfluid helium nanodroplets is investigated by means of femtosecond pump-probe spectroscopy. The employed resonant three-photon-ionization scheme is studied in a wide wavelength range and different pathways leading to K$^+_2$-formation are identified. While the wave packet dynamics of the electronic ground state is not influenced by the helium environment, perturbations of the electronically excited states are observed. The latter reveal a strong time dependence on the timescale 3-8 ps which directly reflects the dynamics of desorption of K$_2$ off the helium droplets

The primary structure of three hemoglobin chains from the indigo snake (Drymarchon corais erebennus, Serpentes): First evidence for αD chains and two β chain types in snakes

The hemoglobin of the indigo snake (Drymarchon corais erebennus, Colubrinae) consists of two components, HbA and HbD, in the ratio of 1:1. They differ in both their alpha and beta chains. The amino acid sequences of both alpha chains (alpha(A) and alpha(D)) and one beta chain (betaI) were determined. The presence of an alpha(D)chain in a snake hemoglobin is described for the first time. A comparison of all snake beta chain sequences revealed the existence of two paralogous beta chain types in snakes as well, which are designated as betaI and betaII type. For the discussion of the physiological properties of Drymarchon hemoglobin, the sequences were compared with those of the human alpha and beta chains and those of the closely related water snake Liophis miliaris where functional data are available. Among the heme contacts, the substitution alpha(D)58(E7)His-->Gln is unusual but most likely without any effect. The residues responsible for the main part of the Bohr effect are the same as in mammalian hemoglobins. In each of the three globin chains only two residues at positions involved in the alpha1/beta2 interface contacts, most important for the stability and the properties of the hemoglobin molecule, are substituted with regard to human hemoglobin. On the contrary, nine, eleven, and six alpha1/beta1 contact residues are replaced in the alpha(A), alpha(D), betaI chains, respectively

Calculations of Shear Moduli of Three-Ply Cross-Laminated Wood Panels from Shear Moduli of Individual Laminae

To study in detail the effect of deflection caused by shear force of cross-laminated panels, shear modulus, apparent modulus of elasticity (MOE), and deflection caused by shear force of cross-laminated panels with different component ratios of laminae thicknesses were investigated using the equation derived for calculating shear modulus of a three-ply laminated beam from the shear moduli of individual lamina. The calculated shear modulus for C⊥ type increased markedly with increasing core laminae thickness, and that for C∥ type decreased markedly with increasing core laminae thickness. Also, the calculated shear modulus for C⊥ (45) type was higher than that for C⊥ (90) type at every core laminae thickness, whereas the calculated shear modulus for C∥ (45) was higher than that for C∥ (90) type at every core laminae thickness. The calculated value of the apparent MOE showed good agreement with measured value, and it was found that the apparent MOE can be calculated from true MOE and shear moduli of lamina. The percentage of deflection caused by shear force (Ysc) calculated from the calculated apparent MOE was close to that (Ys) calculated from the measured apparent MOE. From these results, the validity of the derived equation for calculating shear moduli of laminated panels from individual lamina was proven once more

Time-resolved Four-body Coulomb Explosion Imaging of Correlated Dynamics of Hydrogen Atoms in Acetylene Dication

The correlated motion of the two deuterium atoms associated with the hydrogen migration and structural deformation to non-planar geometry are identified in acetylene dication by the time-resolved four-body Coulomb explosion imaging

Time-resolved Four-body Coulomb Explosion Imaging of Correlated Dynamics of Hydrogen Atoms in Acetylene Dication

The correlated motion of the two deuterium atoms associated with the hydrogen migration and structural deformation to non-planar geometry are identified in acetylene dication by the time-resolved four-body Coulomb explosion imaging

Quantum property of solid hydrogen as revealed by high-resolution laser spectroscopy

Pure vibrational overtone transitions of solid parahydrogen were studied using high-resolution laser spectroscopy. Extremely narrow spectral linewidth (~20 MHz) allowed us to observe rich spectral structure that originates in subtle intermolecular interactions in the crystal. It was found that anisotropy of the distribution of zero-point lattice vibration of hydrogen molecules perturbs the energy levels of the vibrationally excited states significantly. Large amplitude of the zero-point lattice vibration being an intrinsic nature of quantum solids, was directly observed from the present high-resolution spectroscopy. The first observation of a pure vibrational overtone transition of solid orthodeuterium is also discussed

Ultrafast Nonlinear Double Excitations of He in Intense EUV FEL Fields

Three-photon double excitation of He in intense EUV FEL fields is studied by the shot-by-shot photoelectron spectroscopy, revealing the enhancement by resonances to the doubly excited states converging to the He+ N=3 level