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

Atomic Resonance and Scattering

Contains reports on eight research projects.National Science Foundation (Grant PHY79-09743)National Bureau of Standards (Grant NB-8-NAHA-3017)Joint Services Electronics Program (Contract DAAG29-80-C-0104)National Science Foundation (Grant PHY82-10486)U.S. Navy - Office of Naval Research (Contract N00014-79-C-0183)National Science Foundation (Grant CHE79-02967-A04)U.S. Air Force - Office of Scientific Research (Contract AFOSR-81-0067)Joint Services Electronics Program (Contract DAAG29-83-K-0003

The choice of self-rated health measures matter when predicting mortality: evidence from 10 years follow-up of the Australian longitudinal study of ageing

<p>Abstract</p> <p>Background</p> <p>Self-rated health (SRH) measures with different wording and reference points are often used as equivalent health indicators in public health surveys estimating health outcomes such as healthy life expectancies and mortality for older adults. Whilst the robust relationship between SRH and mortality is well established, it is not known how comparable different SRH items are in their relationship to mortality over time. We used a dynamic evaluation model to investigate the sensitivity of time-varying SRH measures with different reference points to predict mortality in older adults over time.</p> <p>Methods</p> <p>We used seven waves of data from the Australian Longitudinal Study of Ageing (1992 to 2004; N = 1733, 52.6% males). Cox regression analysis was used to evaluate the relationship between three time-varying SRH measures (global, age-comparative and self-comparative reference point) with mortality in older adults (65+ years).</p> <p>Results</p> <p>After accounting for other mortality risk factors, poor global SRH ratings increased mortality risk by 2.83 times compared to excellent ratings. In contrast, the mortality relationship with age-comparative and self-comparative SRH was moderated by age, revealing that these comparative SRH measures did not independently predict mortality for adults over 75 years of age in adjusted models.</p> <p>Conclusions</p> <p>We found that a global measure of SRH not referenced to age or self is the best predictor of mortality, and is the most reliable measure of self-perceived health for longitudinal research and population health estimates of healthy life expectancy in older adults. Findings emphasize that the SRH measures are not equivalent measures of health status.</p

Social Relationships and Mortality Risk: A Meta-analytic Review

In a meta-analysis, Julianne Holt-Lunstad and colleagues find that individuals' social relationships have as much influence on mortality risk as other well-established risk factors for mortality, such as smoking

EXPERIMENTAL MAPPING OF THE ABSOLUTE VALUE OF THE ELECTRONIC TRANSITION DIPOLE MOMENT FUNCTION μe(R)\mu_{e}(R) OF THE 7^{7}Li2_{2} A1Σu+−X1Σg+A^{1}\Sigma^{+}_{u}-X^{1}\Sigma^{+}_{g} SYSTEM

Author Institution: Physics Department, Temple University, Philadelphia, PA 19122; Physics Department, Lehigh University, Bethlehem, PA 18015; Physics Department, Temple University, Philadelphia, PA 19122Continuous wave (CW) triple resonance laser spectroscopy} was used to map the absolute value of the electronic transition dipole moment function $\mu_e(R)$ of the $^{7}$Li$_{2}$ A-X system. In this work, the transition dipole moment matrix elements of specific rovibronic molecular transitions were first determined by fitting the observed Autler-Townes splitting spectra. Then by employing the R-centroid approximation, or a multi-variable fit involving higher moments of R, $\mu_e(R)$ has been determined within a relatively large range of internuclear distance R. Finally, this electronic transition dipole moment function is compared with the ab initio calculations with very good agreement

EXPERIMENTAL MAPPING OF THE ABSOLUTE VALUE OF THE ELECTRONIC TRANSITION DIPOLE MOMENT FUNCTION μe(R)\mu_{e}(R) OF THE Na2_{2} A1Σu+−X1Σg+A^{1}\Sigma^{+}_{u}-X^{1}\Sigma^{+}_{g} SYSTEM

Author Institution: Physics Department, Temple University, Philadelphia, PA 19122; Physics Department, Lehigh University, Bethlehem, PA 18015; Physics Department, Temple University, Philadelphia, PA 19122\maketitle The absolute value of the transition dipole momentfunction $\mu_e(R)$ of the $A^{1}\Sigma^{+}_{u}-X^{1}\Sigma^{+}_{g}$ band of Na$_{2}$ was mapped experimentally within a relatively large range of internuclear distance R. The transition dipole moment matrix element of a set of rovibrational transitions between the $A^{1}\Sigma^{+}_{u}$ and $X^{1}\Sigma^{+}_{g}$ states was measured using the Autler-Townes (AT) effect}. By employing the R-centroid approximation, or a fit with a polynomial function involving the higher R-moments, $\mu_e$ as function of the internuclear distance was constructed. The AT effect based measurements give the absolute value of $\mu_e$ which can be used to "normalize" the transition dipole moment functions $\mu_e(R)$ obtained with other experimental techniques, such as line intensity based measurements, which in general give only the relative behavior of $\mu_e(R)$