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141.
Bichenkova EV Yu X Bhadra P Heissigerova H Pope SJ Coe BJ Faulkner S Douglas KT 《Inorganic chemistry》2005,44(12):4112-4114
Octahedral tris-chelate complexes [M(II)(bpy)(3)](2+) (M = Ru or Os, bpy = 2,2'-bipyridyl), covalently attached to the 3'- and 5'-phosphates of two oligonucleotides, are juxtaposed when hybridized contiguously to a fully complementary DNA target. Visible metal-to-ligand charge-transfer (MLCT) excitation of the [Ru(II)(bpy)(3)](2+) unit leads to resonance energy transfer to the MLCT state of the [Os(II)(bpy)(3)](2+) moiety, with the energy transfer efficiency depending on the degree of hybridization. The extent of attenuation of the intense red luminescence from the Ru(II) chromophore hence allows highly sensitive structural probing of the assembly and constitutes a novel approach to DNA sensing which is capable of detecting mutations. 相似文献
142.
Ammonium salts of five new heteropolytungstates, [NaSb9W21O86M3]12,9− (M=MnII, FeIII, CoII, NiII, CuII) have been prepared and characterized by elemental analysis, visible and i.r. spectroscopy, magnetic susceptibility measurements,
and cyclic voltammetry. Evidence for ligand substitution at the M cation centres is presented, and possible binding sites
for M on the polyanion surface are discussed. 相似文献
143.
The Positive Action conjecture requires that the action of any asymptotically Euclidean 4-dimensional Riemannian metric be positive, vanishing if and only if the space is flat. Because any Ricci flat, asymptotically Euclidean metric has zero action and is local extremum of the action which is a local minimum at flat space, the conjecture requires that there are no Ricci flat asymptotically Euclidean metrics other than flat space, which would establish that flat space is the only local minimum. We prove this for metrics onR
4 and a large class of more complicated topologies and for self-dual metrics. We show that ifR
0 there are no bound states of the Dirac equation and discuss the relevance to possible baryon non-conserving processes mediated by gravitational instantons. We conclude that these are forbidden in the lowest stationary phase approximation. We give a detailed discussion of instantons invariant under anSU(2) orSO(3) isometry group. We find all regular solutions, none of which is asymptotically Euclidean and all of which possess a further Killing vector. In an appendix we construct an approximate self-dual metric onK3 — the only simply connected compact manifold which admits a self-dual metric. 相似文献
144.
Dr. Alex T. O'Neil Jade Pope Prof. John A. Harrison Prof. Jonathan A. Kitchen 《欧洲无机化学杂志》2023,26(30):e202300358
We report the synthesis of a new pyrene, dipicolinic acid-based ligand ( L1H ) and its corresponding multi-emissive and multifunctional europium complex [Eu( L1 )3] that is capable of single component color switchable emission from red to blue and also white. At high concentration (10 mM) the single component system results in near pure white emission (CIE coordinates x,y=0.329, 0.324). Furthermore, the system showed ratiometric oxygen sensing with oxygen significantly quenching the pyrene centered emission but not the Eu3+ emission, resulting in an overall emission color change from blue to red on increasing oxygen content. 相似文献
145.
146.
The first examples of polyoxometalate structures that incorporate embedded chelated heteroatoms point to new possibilities for stereochemical control of applications. 相似文献
147.
We construct the general solution for nonextremal charged rotating black holes in five-dimensional minimal gauged supergravity. They are characterized by four nontrivial parameters: namely, the mass, the charge, and the two independent rotation parameters. The metrics in general describe regular rotating black holes, providing the parameters lie in appropriate ranges so that naked singularities and closed timelike curves (CTCs) are avoided. We calculate the conserved energy, angular momenta, and charge for the solutions, and show how supersymmetric solutions arise in a Bogomol'nyi-Prasad-Sommerfield limit. These have naked CTCs in general, but for special choices of the parameters we obtain new regular supersymmetric black holes or smooth topological solitons. 相似文献
148.
F.W. Büsser L. Camilleri L. Di Lella B.G. Pope A.M. Smith B.J. Blumenfeld S.N. White A.F. Rothenberg S.L. Segler M.J. Tannenbaum M. Banner J.B. Chèze J.L. Hamel H. Kasha J.P. Pansart G. Smadja J. Teiger H. Zaccone A. Zylberstejn 《Physics letters. [Part B]》1975,56(5):482-486
In an experiment performed at the CERN Intersecting Storage Rings (ISR), 11 e+e? pairs of high invariant mass value (> 2.5 GeV/c2) have been observed. Of these events, 9 can be interpreted as arising from the reaction p + p → J (3.1) + anything. the cross-section for this reaction is estimated and compared with the result obtained at lower centre-of-mass energies. 相似文献
149.
When an erbium-doped fluoride fiber was pumped with a red dye laser beam that resonantly excites the (4)F(9/2) state, we detected efficient violet upconversion emission from the (2)P(3/2) state that is much stronger than the green upconversion emission from the (4)S(3/2) state. Such unusual violet emission was found to be due to a three-photon excitation process. 相似文献
150.