Search results for " solution"
showing 10 items of 3084 documents
Quasilinear Dirichlet Problems with Degenerated p-Laplacian and Convection Term
2021
The paper develops a sub-supersolution approach for quasilinear elliptic equations driven by degenerated p-Laplacian and containing a convection term. The presence of the degenerated operator forces a substantial change to the functional setting of previous works. The existence and location of solutions through a sub-supersolution is established. The abstract result is applied to find nontrivial, nonnegative and bounded solutions.
New planar polynitrile dianion and its first coordination polymer with unexpected short M⋯M contacts (tcno2−=[(NC)2CC(O)C(CN)2]2−)
2008
International audience; A new planar polynitrile dianion ([tcno]2− = [(NC)2CC(O)C(CN)2]2−) has been synthesized as its potassium salt, K2[tcno] (1). The crystallization of 1 by the slow evaporation of an aqueous solution at room temperature gave two types of colourless crystals having two different shapes [1-A: fine plates and 1-B: needles] for which the crystal structure determinations showed similar geometries for the polynitrile anion in both the structures. The combination of this novel dianion with Cu(II) led to the coordination complex [Cu(tcno)2(H2O)2] (2), which constitutes the first coordination complex of this dianion. The structure of 2 can be described as a coordination polymer …
Rational design of aminoanthraquinones for colorimetric detection of heavy metal ions in aqueous solution
2011
A family of water-soluble colorimetric chemosensors incorporating an anthraquinone signalling subunit functionalized with a polyamine chain that bears hydrophilic diethoxyphosphoryl moieties was prepared with the aim of assaying metal cations. The outstanding UV-Vis absorption properties of the 1-aminoanthraquinone chromophore allowed the efficient visual detection and quantification of copper(II) ions by chelators L(1)-L(3) in buffered aqueous solution. Moreover, the visible response of L(2) is not interfered by addition of large excesses of 13 common metal ions, whereas chemosensor L(3) produces also a color change in the presence of equimolar amounts of lead(II). Considering the 134 nm g…
Deuterated Molecular Ruby with Record Luminescence Quantum Yield
2017
The recently reported luminescent chromium(III) complex 13+ ([Cr(ddpd)2]3+; ddpd=N,N’-dimethyl-N,N’-dipyridine-2-yl-pyridine-2,6-diamine) shows exceptionally strong near-IR emission at 775 nm in water under ambient conditions (F=11%) with a microsecond lifetime as the ligand design in 13+ effectively eliminates non-radiative decay pathways, such as photosubstitution, back-intersystem crossing, and trigonal twists. In the absence of energy acceptors, such as dioxygen, the remaining decay pathways are energy transfer to high energy solvent and ligand oscillators, namely OH and CH stretching vibrations. Selective deuteration of the solvents and the ddpd ligands probes the efficiency of these o…
Costs of Using Hybrid Cloud Infrastructure: Towards a General Framework
2012
Cloud computing infrastructure is a state-of-the-art computing as a utility paradigm, offering individuals and organizations instantly-available and scalable computing capacity. Organizations may deploy the cloud infrastructure in own data centers, as a private cloud, or use the public on-demand cloud infrastructure charged on a pay-per-use basis. The organizations may also adopt a hybrid solution, i.e. use public cloud capacity to complement the resources in the private cloud, e.g. during the periods of rapid growth in the demand. One of the important factors that affect the organizations’ decisions to adopt a hybrid cloud is the total cost of acquiring and managing the infrastructure. In …
Electrically Conductive Phthalocyanine Assemblies. Structural and Non-Integer Oxidation Number Considerations
1990
Aggregation is a well-known phenomenon in phthalocyanine chemistry. Interactions can occur between adjacent phthalocyanine rings, both in organic and aqueous phases, resulting in coupling between the electronic states of two, or more, phthalocyanine units [1].
Exchange Coupling in Cyano-Bridged Homodinuclear Cu(II) and Ni(II) Complexes: Synthesis, Structure, Magnetism, and Density Functional Theoretical St…
2001
The synthesis and structural characterization of several new cyano-bridged copper(II) and nickel(II) homodinuclear complexes is presented. The measure of magnetic properties for these complexes is complemented with a computational study of the exchange coupling for several model structures representing this family of compounds. The influence of several factors on the coupling constant has been examined, coordination position occupied by the bridging ligand, distortions of the coordination environment, and relative disposition of the cyanide ion with respect to the M-M vector. Comparison of experimental and calculated coupling constants allows for the rationalization of the most relevant fea…
13C nuclear magnetic resonance study of some phosphinolipids: Assignments and conformational studies
1989
13C chemical shifts and 31P, 13C spin-spin coupling constants are reported for six model phosphinates and eight synthetic phosphinolipids. The complex spectra of the synthetic phosphinolipids could be assigned from increments and couplings derived from the model compounds. Based on these investigations the 3J(PC) couplings of 7–15 Hz indicate a preferential trans orientation of the respective head-group carbon relative to the phosphorus. This behaviour is similar to that of natural phosphatidylcholine lipids.
Non-Markovian master equation for the XX central spin model
2008
The non-Markovian correlated projection operator technique is applied to the model of a central spin coupled to a spin bath through non uniform XX Heisenberg coupling. The second order results of the Nakajima-Zwanzig and of the time-convolutionless methods are compared with the exact solution considering a fully polarized initial bath state.
Existence and multiplicity of periodic solutions for second order Hamiltonian systems depending on a parameter
2013
The existence of at least one nontrivial periodic solution for a class of second order Hamiltonian systems depending on a parameter is obtained, under an algebraic condition on the nonlinearity G and without requiring any asymptotic behavior neither at zero nor at infinity. The existence is still deduced in the particular case when G is subquadratic at zero. Finally, two multiplicity results are proved if G, in addition, is required to fulfill some different Ambrosetti-Rabinowitz type superquadratic conditions at infinity. The approach is fully variational. © Heldermann Verlag.