Circular Rydberg states of atomic hydrogen in an arbitrary magnetic field

We report a theoretical scheme using a B-spline basis set to improve the poor computational accuracy of circular Rydberg states of hydrogen atoms in the intermediate magnetic field. This scheme can produce high accuracy energy levels and valid for an arbitrary magnetic field. Energy levels of hydrogen are presented for circular Rydberg states with azimuthal quantum numbers $|m|$ = 10 - 70 as a function of magnetic field strengths ranging from zero to 2.35 $\times$ 10$^9$ T. The variation of spatial distributions of electron probability densities with magnetic field strengths is discussed and competition between Coulomb and magnetic interactions is illustrated.Comment: 14 pages, 2 figure

Numerical investigation into the blasting-induced damage characteristics of rocks considering the role of in-situ stresses and discontinuity persistence

This paper presents a 3D coupled Smoothed Particle Hydrodynamics (SPH) and Finite Element Method (FEM) model, which was developed to investigate the extent of damage zone and fracture patterns in rock due to blasting. The RHT material model was used to simulate the blasting-induced damage in rock. The effects of discontinuity persistence and high in-situ stresses on the evolution of blasting-induced damage were investigated. Results of this study indicate that discontinuity persistence and spatial distribution of rock bridges have a significant influence on the evolution of blasting-induced damage. Furthermore, high in-situ stresses also have a significant influence on the propagation of blasting-induced fractures, as well as the patterns of fracture networks. It is also shown that the blasting-induced cracks are often induced along the direction of the applied high initial stresses. Moreover, additional cracks are normally generated at the edges of the rock bridges probably due to the relatively high stress concentration

Three-dimensional DEM investigation of the fracture behaviour of thermally degraded rocks with consideration of material anisotropy

A complete understanding of the fracture behaviour of anisotropic rocks under elevated temperatures is fundamentally important for rock and reservoir engineering applications. This paper shows a three-dimensional numerical investigation of the fracture behaviour of anisotropic sandstone, with consideration of the effects of temperature and material anisotropy. In the study, a 3D semi-circular bend (SCB) model was established by using the Discrete Element Method (DEM). The thermal responses of different minerals and the strength anisotropy of incipient bedding planes were considered in the model. The DEM model was calibrated against a series of laboratory experiments on Midgley Grit sandstone (MGS) that exhibits intrinsic anisotropy. The pure mode I, mode II, and mixed-mode (I+II) fracture characteristics of the MGS were investigated under elevated temperatures (up to 600 °C) using the established DEM model. The thermal degradation (i.e., fracturing) of the rock, the fracture load, the evolution of micro-cracks, and the stress-strain relationship around notch tips were analysed, with emphasis on enlightening the micro-mechanisms underlying the fracture behaviour. The results of the study were discussed and then compared with experimental observations and theoretical predictions

Interplay of Electron-Phonon Interaction and Electron Correlation in High Temperature Superconductivity

We study the electron-phonon interaction in the strongly correlated superconducting cuprates. Two types of the electron-phonon interactions are introduced in the $t-J$ model; the diagonal and off-diagonal interactions which modify the formation energy of the Zhang-Rice singlet and its transfer integral, respectively. The characteristic phonon-momentum $(\vec q)$ and electron-momentum $(\vec k)$ dependence resulted from the off-diagonal coupling can explain a variety of experiments. The vertex correction for the electron-phonon interaction is formulated in the SU(2) slave-boson theory by taking into account the collective modes in the superconducting ground states. It is shown that the vertex correction enhances the attractive potential for the d-wave paring mediated by phonon with $\vec q=(\pi(1-\delta), 0)$ around $\delta \cong 0.3$ which corresponds to the half-breathing mode of the oxygen motion.Comment: 14 pages, 13 figure

Molecular characterization of different Triticum monococcum ssp. monococcum Glu-A1^mx alleles

High-molecular-weight glutenin subunits (HMW-GSs) are important seed storage proteins associated with bread-making quality in common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD). Variation in the Glu-A1x locus in common wheat is scare. Diploid Triticum monococcum ssp. monococcum (2n = 2x = 14, AmAm) is the first cultivated wheat. In the present study, allelic variations at the Glu-A1mx locus were systematically investigated in 197 T. monococcum ssp. monococcum accessions. Out of the 8 detected Glu-A1mx alleles, 5 were novel, including Glu-A1m-b, Glu-A1m-c, Glu-A1m-d, Glu-A1m-g, and Glu-A1m-h. This diversity is higher than that of common wheat. Compared with 1Ax1 and 1Ax2*, which are present in common wheat, these alleles contained three deletions/insertions as well as some single nucleotide polymorphism variations that might affect the elastic properties of wheat flour. New variations in T. monococcum probably occurred after the divergence between A and Am and are excluded in common wheat populations. These allelic variations could be used as novel resources to further improve wheat quality

Von Hippel-Lindau mutations disrupt vascular patterning and maturation via Notch

Von Hippel-Lindau (VHL) gene mutations induce neural tissue hemangioblastomas, as well as highly vascularized clear cell renal cell carcinomas (ccRCCs). Pathological vessel remodeling arises from misregulation of HIFs and VEGF, among other genes. Variation in disease penetrance has long been recognized in relation to genotype. We show Vhl mutations also disrupt Notch signaling, causing mutation-specific vascular abnormalities, e.g., type 1 (null) vs. type 2B (murine G518A representing human R167Q). In conditional mutation retina vasculature, Vhl-null mutation (i.e., UBCCreER/+Vhlfl/fl) had little effect on initial vessel branching, but it severely reduced arterial and venous branching at later stages. Interestingly, this mutation accelerated arterial maturation, as observed in retina vessel morphology and aberrant α-smooth muscle actin localization, particularly in vascular pericytes. RNA sequencing analysis identified gene expression changes within several key pathways, including Notch and smooth muscle cell contractility. Notch inhibition failed to reverse later-stage branching defects but rescued the accelerated arterialization. Retinal vessels harboring the type 2B Vhl mutation (i.e., UBCCreER/+Vhlfl/2B) displayed stage-specific changes in vessel branching and an advanced progression toward an arterial phenotype. Disrupting Notch signaling in type 2B mutants increased both artery and vein branching and restored arterial maturation toward nonmutant levels. By revealing differential effects of the null and type 2B Vhl mutations on vessel branching and maturation, these data may provide insight into the variability of VHL-associated vascular changes - particularly the heterogeneity and aggressiveness in ccRCC vessel growth - and also suggest Notch pathway targets for treating VHL syndrome

Tensor Correlations Measured in 3He(e,e'pp)n

We have measured the 3He(e,e'pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum, $p_{tot}$. For pair relative momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low $p_{tot}$ and rises to approximately 0.5 at large $p_{tot}$. This shows the dominance of tensor over central correlations at this relative momentum.Comment: 4 pages, 4 figures, submitted to PR

Measurement of the nuclear multiplicity ratio for Ks0K^0_s hadronization at CLAS

The influence of cold nuclear matter on lepto-production of hadrons in semi-inclusive deep inelastic scattering is measured using the CLAS detector in Hall B at Jefferson Lab and a 5.014 GeV electron beam. We report the $K_s^0$ multiplicity ratios for targets of C, Fe, and Pb relative to deuterium as a function of the fractional virtual photon energy $z$ transferred to the $K_s^0$ and the transverse momentum squared $p_{T}^2$ of the $K_s^0$. We find that the multiplicity ratios for $K^0_s$ are reduced in the nuclear medium at high $z$ and low $p_{T}^2$, with a trend for the $K^0_s$ transverse momentum to be broadened in the nucleus for large $p_{T}^2$.Comment: Submitted to Phys. Lett.

Coherent Photoproduction of pi^+ from 3^He

We have measured the differential cross section for the $\gamma$$^3$He$\rightarrow \pi^+ t$ reaction. This reaction was studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Real photons produced with the Hall-B bremsstrahlung tagging system in the energy range from 0.50 to 1.55 GeV were incident on a cryogenic liquid $^3$He target. The differential cross sections for the $\gamma$$^3$He$\rightarrow \pi^+ t$ reaction were measured as a function of photon-beam energy and pion-scattering angle. Theoretical predictions to date cannot explain the large cross sections except at backward angles, showing that additional components must be added to the model.Comment: 11 pages, 16 figure