1,597 research outputs found

    Dibromidobis[1-(2-bromo­benz­yl)-3-(pyrimidin-2-yl)-1H-imidazol-2(3H)-one]copper(II)

    Get PDF
    In the title complex, [CuBr2(C14H11BrN4O)2], the CuII ion is located on an inversion centre and is coordinated by two ketonic O atoms, two N atoms and two Br atoms, forming a distorted octahedral coordination environment. The two carbonyl groups are trans positioned with C=O bond lengths of 1.256 (5) Å, in agreement with a classical carbonyl bond. The Cu—O bond length is 2.011 (3) Å. The two bromo­benzyl rings are approximately parallel to one another, forming a dihedral angle of 70.1 (4)° with the coordination plane

    Experimental high-intensity three-photon entangled source

    Full text link
    We experimentally realize a high-intensity three-photon Greenberger-Horne-Zeilinger (GHZ) entanglement source directly following the proposal by Rarity and Tapster [J. G. Rarity and P. R. Tapster, Phys. Rev. A 59, R35 (1999)]. The threefold coincidence rate can be more than 200 Hz with a fidelity of 0.811, and the intensity can be further improved with moderate fidelity degradation. The GHZ entanglement is characterized by testing the Bell-Mermin inequality and using an entanglement witness operator. To optimize the polarization-entangled source, we theoretically analyze the relationship between the mean photon number of the single-photon source and the probability of parametric down-conversion.Comment: 4 pages, 4 figure

    Bis[2,6-bis­(4,5-dihydro-1H-imidazol-2-yl)pyridine]manganese(II) bis­(per­chlorate) acetonitrile solvate

    Get PDF
    In the cation of the title compound, [Mn(C11H13N5)2](ClO4)2·CH3CN, the metal atom is located on a twofold rotation axis and is six-coordinated by six N atoms from two different 2,6-bis­(4,5-dihydro-1H-imidazol-2-yl)pyridine (bip) ligands in a distorted octahedral geometry. The O atoms of the perchlorate anions are disordered with occupancies in the ratio 0.593 (10):0.407 (10). In the crystal, mol­ecules are stabilized by two N—H⋯O hydrogen bonds, forming zigzag chains along the a axis, which are further inter­connected by N—H⋯O hydrogen bonds and π–π inter­actions [centroid–centroid distance = 3.50 (1) Å] into a three-dimensional network

    1,4-Bis(4,5-dihydro-1H-imidazol-2-yl)benzene–terephthalic acid–water (1/1/4)

    Get PDF
    The asymmetric unit of the title compound, C12H14N4·C8H6O4·4H2O, consists of one half of the 1,4-bis­(4,5-dihydro-1H-imidazol-2-yl)benzene (bib) mol­ecule, one half of the terephthalic acid (TA) mol­ecule and two water mol­ecules. Both the bib and the TA mol­ecules reside on crystallographic inversion centers, which coincide with the centroids of the respective benzene rings. The bib and the TA, together with the water mol­ecules, are linked through inter­molecular O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds, forming a three-dimensional network of stacked layers. Weak inter­molecular C—H⋯O contacts support the stability of the crystal structure

    1,4-Bis(4,5-dihydro-1H-imidazol-2-yl)benzene–4-amino­benzene­sulfonic acid–water (1/2/2)

    Get PDF
    The asymmetric unit of the title compound, C12H14N4·2C6H7NO3S·2H2O, contains one half of a centrosymmetric 1,4-bis­(4,5-dihydro-1H-imidazol-2-yl)benzene (bib) molecule, one 4-amino­benzene­sulfonic acid molecule and one water mol­ecule. In the bib molecule, the imidazole ring adopts an envelope conformation. The benzene rings of bib and 4-aminobenzenesulfonic acid are oriented at a dihedral angle of 21.89 (4)°. In the crystal structure, inter­molecular N—H⋯O, O—H⋯N and O—H⋯O inter­actions link the mol­ecules into a three-dimensional network. Weak π–π contacts between the benzene and imidazole rings and between the benzene rings [centroid–centroid distances = 3.895 (1) and 3.833 (1) Å, respectively] may further stabilize the structure

    Principal Component Regression Analysis of Nutrition Factors and Physical Activities with Diabetes

    Get PDF
    The associations of nutrition factors and physical activities with adult diabetes are inconsistent; while most of these factors are inter correlated. The aims of this study are to overcome the disturbance of the multicollinearity of the risk factors and examine the associations of these factors with diabetes using the principal component analysis (PCA) and regression analysis with principal component scores (PCS). Totally, 659 adults with diabetes and 2827 non-diabetic were selected from the 2012 Health Information National Trends Survey (HINTS 4, Cycle 2). PCA was utilized to deal with multicollinearity of the risk factors. Weighted univariate and multiple logistic regression analyses were used to estimate the associations of potential factors and PCS with diabetes. The odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. The first 3 PCs for nutrition factors and physical activities could explain 70% variances. The first principal component (PC1) is a measure of nutrition factors (fruit and vegetables consumption), PC2 is a measure for physical activities (moderate exercise and strength training), and PC3 is about calorie information use and soda use. Weighted multiple logistic regression showed that African Americans, middle aged adults (45-64 years), elderly (65+), never married, and with lower education were associated with increased odds of diabetes. After adjusting for others factors, the PC1 showed marginal association with diabetes (OR=0.84, 95% CI=0.70-1.01); while PC2 and PC3 revealed significant associations with diabetes (OR=0.73, 95% CI=0.61-0.86 and OR=0.85, 95% CI=0.74-0.99, respectively). In conclusion, PCA can be used to reduce the indicators in complex survey data. The first 3 PCs of nutrition factors and physical activities were associated with diabetes. Promotion of health food and physical activities should be encouraged to help decrease the prevalence of diabetes

    Chemical Composition, Fiber Morphology, and Pulping of P. Bolleana Lauche

    Get PDF
    The chemical composition and fiber morphology of the P. bolleana Lauche was assessed for its suitability for pulping and papermaking. The P. bolleana Lauche used in this study contained a low amount of lignin, but higher quantities of cellulose and hemicelluloses. It was found that morphological indices of P. bolleana Lauche were adequate for pulping and papermaking. The pulping of this wood was carried out using conventional kraft and soda pulping process under varying conditions. The results indicated that at higher sulfidity (24%-32%) with lower EA (14-16%), higher yields, and viscosity of pulping were obtained with an acceptable kappa number. Kraft pulp of P. bolleana Lauche obtained at given conditions (EA 14-16%; sulfidity 24-32%) provided paper sheets with greater tensile strength, burst index and tear index, at the same beating degree
    corecore