{μ2-1,4-Bis[2-(4-pyrid­yl)ethen­yl]benzene-κ2 N:N′}bis­[bis­(acetyl­acetonato-κ2 O,O′)copper(II)]

The asymmetric unit of the title compound, [Cu2(C5H7O2)4(C20H16N2)], contains half of a centrosymmetric dinuclear mol­ecule. In the mol­ecule, each Cu center is coordinated by four O atoms from two acetyl­acetonate ligands and one N atom from the bridging linear 1,4-bis­[2-(4-pyrid­yl)ethen­yl]benzene ligand in a square-pyramidal geometry. In the crystal structure, weak inter­molecular C—H⋯O hydrogen bonds link mol­ecules into sheets parallel to the bc plane

Controllable Goos-H\"{a}nchen shifts and spin beam splitter for ballistic electrons in a parabolic quantum well under a uniform magnetic field

The quantum Goos-H\"{a}nchen shift for ballistic electrons is investigated in a parabolic potential well under a uniform vertical magnetic field. It is found that the Goos-H\"{a}nchen shift can be negative as well as positive, and becomes zero at transmission resonances. The beam shift depends not only on the incident energy and incidence angle, but also on the magnetic field and Landau quantum number. Based on these phenomena, we propose an alternative way to realize the spin beam splitter in the proposed spintronic device, which can completely separate spin-up and spin-down electron beams by negative and positive Goos-H\"{a}nchen shifts.Comment: 6 pages, 6 figure

N-(4-Amino­phen­yl)-1,8-naphthalimide hemihydrate

The title compound, C18H12N2O2·0.5H2O, was prepared by the reaction of 1,4-phenyl­enediamine with 1,8-naphthalic anhydride in refluxing dimethyl­formamide. The structure is stabilized by N—H⋯O and O—H⋯O hydrogen bonds. There are π–π stacking inter­actions [centroid-centroid distances of 3.718 (2), 3.510 (2) and 3.546 (2) Å] and C—H⋯π inter­actions between the mol­ecules. The water molecule lies on a twofold rotation axis. Its two H atoms are disordered equally over two positions

A WENO Algorithm of the Temperature and Ionization Profiles around a Point Source

We develop a numerical solver for radiative transfer problems based on the weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive flux corrections, in order to solve the temperature and ionization profiles around a point source of photons in the reionization epoch. Algorithms for such simulation must be able to handle the following two features: 1. the sharp profiles of ionization and temperature at the ionizing front (I-front) and the heating front (T-front), and 2. the fraction of neutral hydrogen within the ionized sphere is extremely small due to the stiffness of the rate equations of atom processes. The WENO scheme can properly handle these two features, as it has been shown to have high order of accuracy and good convergence in capturing discontinuities and complicated structures in fluid as well as to be significantly superior over piecewise smooth solutions containing discontinuities. With this algorithm, we show the time-dependence of the preheated shell around a UV photon source. In the first stage the I-front and T-front are coincident, and propagate with almost the speed of light. In later stage, when the frequency spectrum of UV photons is hardened, the speeds of propagation of the ionizing and heating fronts are both significantly less than the speed of light, and the heating front is always beyond the ionizing front. In the spherical shell between the I- and T-fronts, the IGM is heated, while atoms keep almost neutral. The time scale of the preheated shell evolution is dependent on the intensity of the photon source. We also find that the details of the pre-heated shell and the distribution of neutral hydrogen remained in the ionized sphere are actually sensitive to the parameters used. The WENO algorithm can provide stable and robust solutions to study these details.Comment: 24 pages, 7 figures, accepted in New Astronom

6-Oxobenz[de]isoquinolino[2,1-a]benzimidazolium chloride monohydrate

The title compound, C18H11N2O+·Cl−·H2O, was prepared by the reaction of 1,8-naphthalic anhydride with o-phenyl­ene­diamine in DMF. The dihedral angle formed by the phenyl and naphthalic rings is 177.06°. The structure is stabilized by intra­molecular C—H⋯O hydrogen bonds. There are N—H⋯Cl, O—H⋯Cl, C—H⋯O and C—H⋯Cl hydrogen bonds in the structure

Insights into the Mutation-Induced HHH Syndrome from Modeling Human Mitochondrial Ornithine Transporter-1

Human mitochondrial ornithine transporter-1 is reported in coupling with the hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome, which is a rare autosomal recessive disorder. For in-depth understanding of the molecular mechanism of the disease, it is crucially important to acquire the 3D structure of human mitochondrial ornithine transporter-1. Since no such structure is available in the current protein structure database, we have developed it via computational approaches based on the recent NMR structure of human mitochondrial uncoupling protein (Berardi MJ, Chou JJ, et al. Nature 2011, 476:109–113). Subsequently, we docked the ligand L-ornithine into the computational structure to search for the favorable binding mode. It was observed that the binding interaction for the most favorable binding mode is featured by six remarkable hydrogen bonds between the receptor and ligand, and that the most favorable binding mode shared the same ligand-binding site with most of the homologous mitochondrial carriers from different organisms, implying that the ligand-binding sites are quite conservative in the mitochondrial carriers family although their sequences similarity is very low with 20% or so. Moreover, according to our structural analysis, the relationship between the disease-causing mutations of human mitochondrial ornithine transporter-1 and the HHH syndrome can be classified into the following three categories: (i) the mutation occurs in the pseudo-repeat regions so as to change the region of the protein closer to the mitochondrial matrix; (ii) the mutation is directly affecting the substrate binding pocket so as to reduce the substrate binding affinity; (iii) the mutation is located in the structural region closer to the intermembrane space that can significantly break the salt bridge networks of the protein. These findings may provide useful insights for in-depth understanding of the molecular mechanism of the HHH syndrome and developing effective drugs against the disease

A quartic system and a quintic system with fine focus of order 18

AbstractBy using an effective complex algorithm to calculate the Lyapunov constants of polynomial systems En: z˙=iz+Rn(z,z¯), where Rn is a homogeneous polynomial of degree n, in this note we construct two concrete examples, E4 and E5, such that in both cases, the corresponding orders of fine focus can be as high as 18. The systems are given, respectively, by the following ordinary differential equations:E4:z˙=iz+2iz4+izz¯3+5227820723eiθz¯4, where θ∉{kπ±π6,kπ+π2,k∈Z}, andE5:z˙=iz+3z5+20(c+3)9c2−15z4z¯+zz¯4+20(c+3)c29c2−15z¯5, where c is the root between (−3,−5/3) of the equation4155c6−10716c5−63285c4−18070c3+168075c2+205450c+60375=0