3,452 research outputs found

    Flat-band and multi-dimensional fermions in Pb10(PO4)6O4

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    Employing a combination of first-principles calculations and low-energy effective models, we present a comprehensive investigation on the electronic structure of Pb10_{10}(PO4_{4})6_{6}O4_{4}, which exhibits remarkable quasi-one-dimensional flat-band around the Fermi level that contains novel multi-dimensional fermions. These flat bands predominantly originate from px/pyp_x/p_y orbital of the oxygen molecules chain at 4e4e Wyckoff positions, and thus can be well-captured by a four-band tight-binding model. Furthermore, the abundant crystal symmetry inherent to Pb10_{10}(PO4_{4})6_{6}O4_{4} provides an ideal platform for the emergence of various multi-dimensional fermions, including a 0D four-fold degenerated Dirac fermion with quadratic dispersion, a 1D quadratic/linear nodal-line (QNL/LNL) fermion along symmetric kk-paths, 1D hourglass nodal-line (HNL) fermion linked to the Dirac fermion, and a 2D symmetry-enforced nodal surface (NS) found on the kzk_z=π\pi plane. Moreover, when considering the weak ferromagnetic order, Pb10_{10}(PO4_{4})6_{6}O4_{4} transforms into a rare semi-half-metal, which is characterized by the presence of Dirac fermion and HNL fermion at the Fermi level for a single spin channel exhibiting 100%\% spin polarization. Our findings reveal the coexistence of flat bands, diverse topological semimetal states and ferromagnetism within in Pb10_{10}(PO4_{4})6_{6}O4_{4}, which may provide valuable insights for further exploring intriguing interplay between superconductivity and exotic electronic states.Comment: 8 pages, 4 figure

    Aqua[N-(2,5-dihydroxybenzyl)imino­diacetato]copper(II)

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    The title complex, [Cu(C11H11NO6)(H2O)], contains a CuII atom in a distorted square-pyramidal geometry. The metal centre is coordinated in the basal sites by one water mol­ecule and two carboxyl­ate O atoms and one N atom of the tetra­dentate ligand [Cu—O range, 1.9376 (11)–1.9541 (12), Cu—N, 1.9929 (12) Å] while the apical site is occupied by a hydro­quinone O donor atom [Cu—O, 2.3746 (12) Å]. Inter­molecular hydrogen bonding inter­actions involving both hydro­quinone hydr­oxy groups and the coordinated water as donors give a three-dimensional framework structure

    Proizvodnja novog probiotičkog sira tipa Cheddar, veće ACE inhibicijske aktivnosti i većeg udjela γ-aminomaslačne kiseline, s pomoću Lactobacillus casei Zhang, izolirane iz fermentiranoga mliječnog napitka

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    Cheddar cheese has been manufactured with Lactobacillus casei Zhang as the dairy starter adjunct. L. casei Zhang had previously been isolated from koumiss collected from Xilin Guole in Inner Mongolia and characterized in detail with regard to their probiotic potential. The addition of L. casei Zhang to Cheddar cheese had no adverse effects on sensory criteria. The cheese made with 0.1, 1 and 2 % of the probiotic strain L. casei Zhang adjuncts contained high levels of the Lactobacillus after 6 months of ripening with final counts of 9.6·10^7, 7.7·10^7 and 1.02·10^8 CFU/g, respectively. In the ripe control cheese, without the addition of probiotic strain L. casei Zhang, the number of Lactobacillus reached 5.7·107 CFU/g. Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) analysis was used to distinguish the added L. casei Zhang from the natural flora of the cheese and to determine whether L. casei Zhang grew in the cheese. ACE-inhibitory activity and γ-aminobutyric acid (GABA) concentrations in the cheese were measured. Compared with control cheese, experimental cheese with 0.1, 1 and 2 % of probiotic strain L. casei Zhang revealed some increase in ACE-inhibitory activity and GABA mass fraction. In the present study, the production of both ACE-inhibitory activity and GABA in the probiotic cheese with the L. casei Zhang adjunct isolated from koumiss has been found for the first time. The results suggest that cheese with the probiotic strain L. casei Zhang showed good potential for application in the management of hypertension.Proizveden je sir tipa Cheddar s pomoću dodane kulture Lactobacillus casei Zhang, prethodno izolirane iz fermentiranoga mliječnog napitka „koumiss“ (Xilin Guole, središnja Mongolija, Kina). Iscrpno su ispitana probiotička svojstva izolirane kulture. Utvrđeno je da dodatak kulture nije bitno promijenio senzorička svojstva sira. Sir pripremljen s 0,1 % probiotičke kulture imao je nakon 6 mjeseci zrenja 9,6·107 CFU/g, sir s 1 % probiotičke kulture 7,7·107 CFU/g, a sir s 2 % probiotičke kulture 1,02·108 CFU/g bakterija roda Lactobacillus. U zrelom je kontrolnom uzorku sira (bez dodatka L. casei Zhang) broj bakterija Lactobacillus bio 5,7·107 CFU/g. Provedbom ERIC-PCR analize razlučena je dodana kultura L. casei Zhang od prirodne mikroflore sira, te utvrđen njezin rast. Također je izmjerena veća ACE inhibicijska aktivnost te veći udio γ-aminomaslačne kiseline u dobivenom siru, u usporedbi s kontrolnim uzorkom. Rezultati pokazuju da se dodatkom probiotičke kulture L. casei Zhang dobiva sir boljih svojstava, čija veća primjena pridonosi liječenju povišenog arterijskog tlaka
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