cyclo-Tetra-μ-oxido-tetrakis[3-nitro-4-hydroxyphenylarsenic(III)]

The title compound, [As₄O₄(C₆H₄NO₃)₄], has an eight-membered As₄O₄ ring with a slightly twisted boat-chair conformation. The aryl groups complete the threefold coordination for each As atom. Each OH group forms a strong intramolecular O-H⋯O hydrogen bond to the adjacent NO₂ group, with only weak C-H⋯O, O⋯As [3.036 (6)-3.184 (6) Å] and O⋯O [2.921 (10)-2.930 (10) Å] interactions between tetramers

Rising protectionist threat creates risks for Texas

Expanding trade has brought jobs and business to Texas, but has left the state particularly vulnerable to antitrade actions. Texas would suffer greatly if the U.S. and other countries implement protectionist measures.Economic conditions - Texas ; International trade ; Free trade ; North American Free Trade Agreement

Bis[μ-bis(diphenylphosphino)methane-К²P:P’]bis[(saccharinato-КN)- palladium(I)] dichloromethane solvate

The dimeric palladium(I) saccharinate complex [Pd₂(sac)₂(dppm)₂], has been characterized as its di¬chloro¬methane solvate, i.e. [Pd₂(C₇H₄NO₃S)₂(C₂₅H₂₂P₂)₂]•CH₂Cl₂. The complex features a Pd—Pd bond bridged by two dppm ligands, with the saccharinate ligands N-bonded trans to the Pd—Pd bond

Maternal Factors Related to Parenting Young Children with Congenital Heart Disease

The purpose of this study was to compare the early child-rearing practices between mothers of young children with congenital heart disease (CHD) and mothers of healthy children. In addition, maternal stress, parental developmental expectations, and the early behavioral and emotional development of their children were explored. Maccoby’s (1992) socialization theory emphasizing the reciprocal nature of mother-child interactions provided the framework for this study. Findings from quantitative self-report measures and videotaped parent-child interactions showed a remarkable similarity between mothers of children with CHD and mothers of healthy children. In contrast, qualitative data revealed important differences with mothers of CHD children reporting high levels of vigilance with their children. The important role of promoting the principle of normalization among mothers of children with CHD and ensuring a sufficient support system is discussed

Six-coordinate organotin(IV) complexes formed using the Kläui ligands; [CpCo{P(OR′)2O}3]SnR3 − nCln

The complexes [CpCo{P(OR′)2O}3]SnR3 − nCln [R′ = Me, Et; R = Ph, Me] are readily prepared from the corresponding organotin chloride and the sodium salt of the Kläui ligands. The X-ray crystal structures of the full series are reported for R = Ph, n = 0-3, and these show that they are all six-coordinate, including the Ph3Sn derivative which is the first example of a SnC3O3 coordination sphere. 1H, 13C, 31P and 119Sn NMR spectra are reported, and interpreted in terms of significant second-order effects and fluxional processes

Low complexity method for large-scale self-consistent ab initio electronic-structure calculations without localization

A novel low complexity method to perform self-consistent electronic-structure calculations using the Kohn-Sham formalism of density functional theory is presented. Localization constraints are neither imposed nor required thereby allowing direct comparison with conventional cubically scaling algorithms. The method has, to date, the lowest complexity of any algorithm for an exact calculation. A simple one-dimensional model system is used to thoroughly test the numerical stability of the algorithm and results for a real physical system are also given

Electronic Structure and Dynamics of Quasi-One Dimensional Materials

This thesis explores the electronic structure and ultrafast dynamics of quasi- one dimensional (1D) materials by means of high resolution angle-resolved photoemission spectroscopy (ARPES) and femtosecond time-resolved ARPES (trARPES) respectively. Confining electrons to quasi-1D environments induces a range of broken symmetry ground states and emergent properties that result from the increased inter-particle couplings and reduced phase space that such a confinement enforces. Investigating the energy relaxation and transfer between electrons and other degrees of freedom enables fundamental insights into the microscopic mechanisms behind these novel behaviours; for example by reference to characteristic time scales. Furthermore, since quasi-1D objects always interact with a higher dimensional environment, it is also of fundamental interest to investigate the influence that these interactions have on such phases, and whether they play a role in stabilising them. In this work, a number of model quasi-1D systems have been analysed to explore the coupling of 1D objects to a 3D environment, as well as the ultrafast dynamics of photoexcited broken symmetry phases. The bulk 1D compound NbSe3 is found to show behaviour consistent with a dimensional crossover from 1D to 3D as a function of decreasing energy and temperature, resulting from the coupling between individual 1D chains. Intriguingly, residual 1D behaviour is found to persist even in the 3D regime. Additionally, charge density wave gaps in the electronic structure are observed at low temperatures. The candidate 1D system Ag/Si(557) is investigated to reveal its electronic dimensionality. While the doped Fermi surface reveals predominantly two-dimensional behaviour, the influence of the stepped Si substrate anisotropically induces replica states. The atomic nanowire system In/Si(111) is well known to undergo concomitant structural and metal-to-insulator transitions. By resolving the dynamics of multiple individual electronic states following photoexcitation, a detailed picture of the electronic structure evolution is obtained. An impressive agreement between theory and experiment is obtained, allowing important microscopic insights into this system. Finally the spin density wave phase transition in thin films of Cr is driven by photoexcitation, highlighting the role of electron-electron scattering as the mechanism behind this phase. The applicability of an equilibrium-like order parameter is found to be appropriate in this ultrafast transition

Parenting Young Children: Comparison of a Psychoeducational Program in Mexico and the United States

The purpose of this study was to compare the cross-cultural effectiveness of a psychoeducational program with 82 Mexican and 63 American mothers with very young children. The 10-hour program was presented by trained facilitators in Mexico and the United States to small groups of mothers. Results showed that the both groups of mothers significantly increased their expectations and use of nurturing strategies and reduced their use of verbal and corporal punishment with their young children following the program. In addition, the reported frequency of child behavior problems decreased significantly at post-test. The similar results obtained across cultures were explained based on research finding similar parenting practices with young children between Mexican and American parents