716 research outputs found
Electronic structure of the water-oxidation catalyst [(bpy)(2)(OHx)RuORu(OHy)(bpy)(2)](z+): Weak coupling between the metal centers is preferred over strong coupling
No full text
噬菌體xf的抗血清對感染細菌的影響
No full text[[abstract]]當線狀噬菌體xf感染水稻白葉枯病原細菌Xanthomonas Oryjae時，寄主細胞並
不溶解，而仍舊連續生長、增殖，並釋出新生的噬菌體，但是當加入xf之抗血清至
感染細菌中時，感染細菌產生菌落以及產生病毒。（感染中心）的能力喪失。而未
感染的細菌則能於XF抗血清之存在下，正常生長。
抗血清對感染細菌細胞的作用時間是在虹感染後潛伏期之終了（大約感染後２
小時），這個事實表示抗血清作用的地方是在寄主細胞外，或正排出寄主細胞的噬
菌體，以Rifampiuin處理細菌，可以得到吸附噬菌體的細菌細胞、噬菌體因缺少引
導物，不能侵入寄主細胞，即留在細胞表面，和寄主細胞噬菌體的情形相似，加入
Xf抗血清也可以殺死吸附噬菌體的細菌細胞。
以顯微培養技術觀察的結果，發現在培養12小時後，75％的寄主細胞分裂成兩
個細胞，至26小時，大約63％的細胞仍舊停留在二個細胞階段，以放射性測定Xf抗
血清處理的感染細菌，其ＤＮＡ、ＲＮＡ和蛋白質合成能力在二小時以內仍繼續進
行。
因此噬菌體的抗血清處理的感染菌，仍然可以分裂一次。
Exceptionally large room-temperature ferroelectric polarization in the PbNiO3 multiferroic nickelate: First-principles study
No full textWe present a study based on several advanced first-principles methods of the recently synthesized PbNiO3 [J. Am. Chem. Soc. 133, 16920 (2011)], a rhombohedral antiferromagnetic insulator, which crystallizes in the highly distorted R3c crystal structure. We find this compound electrically polarized with a very large electric polarization of similar to 100 mu C/cm(2), thus, even exceeding the polarization of well-known BiFeO3. PbNiO3 is a proper ferroelectric with polarization driven by large Pb-O polar displacements along the [111] direction. Contrary to naive expectations, a definite ionic charge of 4+ for the Pb ion cannot be assigned, and, in fact, the large Pb 6s-O 2p hybridization drives the ferroelectric distortion through a lone-pair mechanism similar to that of other Pb- and Bi-based multiferroics
A study of mu-mu- and e-mu-pairs produced in 450 GeV/c p-Be--collisions in HELIOS, and software development for DELPHI
No full textThe main part of this thesis treats measurements in the HELIOS experiment of the production of e-mu and mu+mu-pairs in 450 GeV/c p-Be collisions. The mumu measurement covers the kinematical covers the kinematical range of 2Mmu < M < 1.5 GeV, 0.03 < xF < 0.25, and 0 < pT < 2 GeV. Production of the vector mesons rho, omega , and phi is observed. The branching ratio omega to mu+mu- is for the first time experimentally measured. The continuum at masses below the mu mass is studied, and compared with the contributions from known sources, normalized to the vector meson peaks in the mu+mu- mass spectrum, and to measurements in this experiment of the mu cross section. The res ult is compared with that of other experiments, discussed in terms of different background estimates used. A significant signal of unlike-sign e-mu-pairs is observed, forming a continuum peaking at a mass below 500 MeV. Correlations between e-mu and neutrino production are studied. The shape of the e-mu mass and missng-energy spectra indicate significant non-charm contributions. A search for lepton-number-violating decays is made, resulting in upper limits on a number of branching ratios. Also discussed here is the author's work in the DELPHI experiment, contributions that are related to analysis of heavy quark production. Keywords: muon. pair, dimuon, dilepton, lepton, low mass, continuum, eta, rho, omega, branching ratio, emu, e-mu, mue, mu-e, muon-electron, electron-muon, electron, charm, neutrino, missing energy</p
A study of mu-mu- and e-mu-pairs produced in 450 GeV/c p-Be--collisions in HELIOS, and software development for DELPHI
No full textThe main part of this thesis treats measurements in the HELIOS experiment of the production of e-mu and mu+mu-pairs in 450 GeV/c p-Be collisions. The mumu measurement covers the kinematical covers the kinematical range of 2Mmu < M < 1.5 GeV, 0.03 < xF < 0.25, and 0 < pT < 2 GeV. Production of the vector mesons rho, omega , and phi is observed. The branching ratio omega to mu+mu- is for the first time experimentally measured. The continuum at masses below the mu mass is studied, and compared with the contributions from known sources, normalized to the vector meson peaks in the mu+mu- mass spectrum, and to measurements in this experiment of the mu cross section. The res ult is compared with that of other experiments, discussed in terms of different background estimates used. A significant signal of unlike-sign e-mu-pairs is observed, forming a continuum peaking at a mass below 500 MeV. Correlations between e-mu and neutrino production are studied. The shape of the e-mu mass and missng-energy spectra indicate significant non-charm contributions. A search for lepton-number-violating decays is made, resulting in upper limits on a number of branching ratios. Also discussed here is the author's work in the DELPHI experiment, contributions that are related to analysis of heavy quark production. Keywords: muon. pair, dimuon, dilepton, lepton, low mass, continuum, eta, rho, omega, branching ratio, emu, e-mu, mue, mu-e, muon-electron, electron-muon, electron, charm, neutrino, missing energy</p
Contractions of Lie bialgebras and quantum algebras
No full textContractions of Lie bialgebras and Hopf algebras are discussed with examples. Especially, it is shown that the Lie bialgebras associated with the compact simple Lie algebras and the quantum doubles associated with the complex simple Lie algebras can be contracted.Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)0ARTICLE2263-2683
FOCK REPRESENTATIONS OF LIE-ALGEBRAS, LOOP ALGEBRAS AND AFFINE LIE-ALGEBRAS
No full textExplicit Fock representations of the classical Lie algebras in terms of boson creation and annihilation operators with an arbitrary highest weight are derived, and a general rule to construct Fock representations of a loop algebra from a boson realization of its corresponding Lie algebra is established. A new kind of lowest weight representations of the affine Lie algebras attached to the classical Lie algebras, which require a zero center, is also presented. Based on these, a simple affinization procedure is given to obtain the Fock representations of level 1 of these affine Lie algebras.Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)0ARTICLE3311-3202
Structural, Electronic, and Ferroelectric Properties of Compressed CdPbO3 Polymorphs
No full textBy means of first-principles calculations based on density functional theory (DFT) and hybrid functional, we studied the structural, electronic, and ferroelectric properties of the two recently synthesized high-pressure perovskite-type (orthorhombic, space group Pnma) and LiNbO3-type (rhombohedral, space group R3c) polymorphs of CdPbO3. Besides providing structural and electronic results in good agreement with available experiments, our results are able to correctly describe the pressure-induced Pnma -> R3c structural phase transition and most importantly predict the realization of proper ferroelectric behavior in LiNbO3-type CdPbO3 with an electric polarization of 52.3 mu C/cm(2). The proper covalent interaction mechanism driving the ferroelectric transition is discussed and explained in terms of the analysis of Born effective charges, potential-energy surfaces, charge density isosurfaces, and electric localization function
DIDACTIC IDEAS AND PEDAGOGICAL CONCEPTS IN THE PARABLES OF XF C. GELLERT
No full text<p>This in the article<strong> </strong>Didactic ideas and pedagogical concepts in the parables of XF C. Gellert about written of C. Gellert " Parable and of the collection of stories " ( " Fabeln und Erzählungen " ). himself of the author classic meaning in the form of parable from the text moving away and allegorical in the form of short instructive poetic parable genre is approaching shows. </p>
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