The anticrossing spectra of the helium line λ(1s4l-1s2p 3 P) = 447.2 nm were measured for 10-30 keV He + -He collisions. The theoretical intensity functions were calculated taking into account cascade processes, the inhomogeneity of the axial electric field in the collision volume and the density distribution of the target He atoms. Comparing the theoretical intensities with the measured ones, the post-collisional states of He atoms were determined. The results indicate that for this projectile-energy range, the electronic charge distributions of the excited-atom states change from almost symmetric to strongly asymmetric ones with large electric dipole moments. This result suggests that for projectile energies of 20-30 keV, Paul-trap promotion becomes the main excitation mechanism.
This paper examines network prominence in a co-prescription network as an indicator of doctor shopping (i.e., fraudulent solicitation of prescriptions from multiple healthcare providers) for opioids. Using longitudinal data from a large commercially insured population, we construct a network where a tie between patients was weighted by the number of shared opioid prescribers. Given prior research suggesting that doctor shopping may be a social process, we hypothesize that active doctor shoppers will occupy central structural positions in this network. We show that network prominence, operationalized using PageRank, was associated with more opioid prescriptions, higher predicted risk for dangerous morphine dosage, opioid overdose, and opioid use disorder, controlling for number of prescribers and other variables. Moreover, as a patient’s own prominence increased over time, so did their risk for these outcomes, compared to their own average level of risk. These findings point to structural properties of co-prescription networks as a promising indicator of social or strategic drug-seeking behavior and overdose risk.
The post-collisional 1s5l (l ⩾ 2) states of He atoms after He+-ion impact (10 keV–28 keV) have been investigated using anticrossing spectroscopy. In particular, the intensity of the spectral line λ(1s5l 3D-1s2p 3P) = 402.6 nm emitted by the impact-excited He atoms was measured as a function of an axial electric field (which varied from −30 kV cm−1 to +30 kV cm−1). By fitting the theoretical intensity functions to the measured ones, the post-collisional states of the atoms and their electric dipole moments were determined. The results indicate that for projectile energies below 20 keV, the electric dipole moments are small; however, for energies above 20 keV, mainly the parabolic Stark states with maximal electric dipole moments are excited. We conclude that in the upper section of the energy range investigated here, the Paul-trap promotion is the dominant excitation mechanism for He+–He collisions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.