Erratum: Proton and Hydrogen Transport through Hydrogen Environments: Ionization and Stripping

Corrected data is provided here for ionization in H+ + H for the laboratory collision energies between 50 and 10,000 keV regarding the integral and differential cross sections, as well as average values of kinematic parameters such as energy loss and projectile scattering angle...Fil: Cariatore, Nelson Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; ArgentinaFil: Schultz, David R.. Northern Arizona University.; Estados Unido

From Simplicity to Complexity via Subcomponent Self-Assembly

Subcomponent self-assembly allows the construction of complex architectures from simple building blocks via the formation of covalent bonds around metal templates. Since both covalent and coordinative bonds are formed reversibly, a wealth of rearrangement reactions are possible involving substitution at both intraligand and metal–ligand bonds. If the possibilities latent within a set of subcomponents and metal ions are understood, one may also select specific structures from among dynamic libraries of products. The parallel preparation of structures from mixtures of subcomponents is also possible, as is the direction of subcomponents to specific sites within product structures

Atomic data for calculation of the intensities of Stark components of excited hydrogen atoms in fusion plasmas

Motional Stark effect (MSE) spectroscopy represents a unique diagnostic tool capable of determining the magnitude of the magnetic field and its direction in the core of fusion plasmas. The primary excitation channel for fast hydrogen atoms in injected neutral beams, with energy in the range of 25-1000 keV, is due to collisions with protons and impurity ions (e.g., He$^{2+}$ and heavier impurities). As a result of such excitation, at the particle density of 10$^{13}$-10$^{14}$ cm$^{-3}$, the line intensities of the Stark multiplets do not follow statistical expectations (i.e., the populations of fine-structure levels within the same principal quantum number $n$ are not proportional to their statistical weights). Hence, any realistic modeling of MSE spectra has to include the relevant collisional atomic data. In this paper we provide a general expression for the excitation cross sections in parabolic states within $n$=3 for an arbitrary orientation between the direction of the motion-induced electric field and the proton-atom collisional axis. The calculations make use of the density matrix obtained with the atomic orbital close coupling method and the method can be applied to other collisional systems (e.g., He$^{2+}$, Be$^{4+}$, C$^{6+}$, etc.). The resulting cross sections are given as simple fits that can be directly applied to spectral modeling. For illustration we note that the asymmetry detected in the first classical cathode ray experiments between the red- and blue-shifted spectral components can be quantitatively studied using the proposed approach.Comment: 11 pages, 6 figure

Correlated Two-Electron Wave Functions of Any Symmetry

Using a procedure originally due to Hylleraas, a convenient expansion in coupled spherical harmonics which terminates in a very small number of terms is applied to the treatment of fully correlated two-electron wave functions of any symmetry (total angular momentum, parity, and spin). Coupled equations satisfied by these wave functions are derived which are well adapted to computation and which we discretize on a numerical lattice utilizing the basis-spline collocation method. Use of this method which relies on very flexible basis functions is intended to facilitate subsequently the consideration of time-dependent rearrangments such as autoionization, photoionization, and electron-impact excitation and ionization. Here, we describe the underlying theoretical and computational methods concerning our treatment of the two-electron problem, the lattice discretization, and partial eigensolution by damped relaxation. Results of explicit calculations are given regarding the ground state and two low-lying singly excited states of helium

A relationship between US healthcare worker smallpox vaccination rates in 2003 and presidential election results in 2004

A statistical relationship exists between state per capita smallpox vaccination rates of healthcare workers in 2003 and state presidential election results in 2004. The potential implications of political influence on national biosecurity decision making are discussed