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981.
Ernesto Martínez Antonio E. Mucientes Francisco J. Poblete Ana Rodríguez 《Reaction Kinetics and Catalysis Letters》2004,81(2):365-371
The catalytic effect of CO2 on the kinetics and yields of peroxynitrite decomposition in the presence of cyanide complexes
was investigated as a function of pH, substrate, bicarbonate and nitrite concentration.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
982.
Ohne Zusammenfassung 相似文献
983.
R.F. Alvarez‐Estrada 《Annalen der Physik》2006,15(6):379-415
We consider a nonequilibrium statistical system formed by many classical non‐relativistic particles of opposite electric charges (plasma) and by the classical dynamical electromagnetic (EM) field. The charges interact with one another directly through instantaneous Coulomb potentials and with the dynamical degrees of freedom of the transverse EM field. The system may also be subject to external influences of: i) either static, but spatially inhomogeneous, electric and magnetic fields (case 1)), or ii) weak distributions of electric charges and currents (case 2)). The particles and the dynamical EM field are described, for any time t > 0, by the classical phase‐space probability distribution functional (CPSPDF) f and, at the initial time (t = 0), by the initial CPSPDF fin. The CPSPDF f and fin, multiplied by suitable Hermite polynomials (for particles and field) and integrated over all canonical momenta, yield new moments. The Liouville equation and fin imply a new nonequilibrium linear infinite hierarchy for the moments. In case 1), fin describes local equilibrium but global nonequilibrium, and we propose a long‐time approximation in the hierarchy, which introduces irreversibility and relaxation towards global thermal equilibrium. In case 2), the statistical system, having been at global thermal equilibrium, without external influences, for t ≤ 0, is subject to weak external charge‐current distributions: then, new hierarchies for moments and their long‐time behaviours are discussed in outline. As examples, approximate mean‐field (Vlasov) approximations are treated for both cases 1) and 2). 相似文献
984.
Edgar Enochs S. Estrada J. R. García-Rozas L. Oyonarte 《Algebras and Representation Theory》2004,7(4):441-456
The study of flat covers and cotorsion envelopes has turned out to be very useful since their existence was proved in [3] for the category of R-modules. The problem is even more interesting in categories of sheaves on a topological space, because these categories do not have enough projectives. But the existence of flat covers and cotorsion envelopes allow us to form flat and cotorsion resolutions to compute cohomology. 相似文献
985.
Four new highly oxygenated guaiane lactones, menverins A–D ( 1 – 4 ), were isolated from the gorgonian Menella verrucosa (Brundin ) from the South China Sea. Their structures and relative configurations were elucidated on the basis of spectroscopic data. All compounds contain a conjugated α‐methyl‐substituted α, β‐unsaturated γ‐lactone moiety, a C(8)?C(9) conjugated with the γ‐lactone moiety, and an exocyclic methylene group at C(4) (trivial numbering). 相似文献
986.
987.
988.
We prove effective upper bounds for the almost periodicity of polynomial Euler products
L(s){\cal L}(s)
in the half-plane of absolute convergence. From this we deduce estimates for the roots of the equation
L(s) = c{\cal L}(s) = c
, where c is any non-zero complex number which is attained by
L(s){\cal L}(s)
. The method relies mainly on effective diophantine approximation. 相似文献
989.
A non-Euclidean crystallographic group F (NEC group, for short) is a discrete subgroup of isometries of the hyperbolic plane H, with compact quotient space H/Г. These groups uniformize Klein surfaces, surfaces endowed with dianalytic structure. These surfaces can be seen as a generalization of Riemann surfaces.
Fundamental polygons play an important role in the study of parametrizations of the Teichmuller space of NEC groups.
In this work we construct a class of right-angled polygons which are fundamental regions of bordered surface NEC groups. The free parameters used in the construction of the polygons give a parametrization of the Teichmuller space. From the parameters we obtain explicit matrices of the generators of the groups. Finally, we give examples to exhibit how different relations between the parameters reflect the existence of automorphisms on the quotient surfaces. 相似文献
Fundamental polygons play an important role in the study of parametrizations of the Teichmuller space of NEC groups.
In this work we construct a class of right-angled polygons which are fundamental regions of bordered surface NEC groups. The free parameters used in the construction of the polygons give a parametrization of the Teichmuller space. From the parameters we obtain explicit matrices of the generators of the groups. Finally, we give examples to exhibit how different relations between the parameters reflect the existence of automorphisms on the quotient surfaces. 相似文献
990.
Driscoll PF Douglass EF Phewluangdee M Soto ER Cooper CG Macdonald JC Lambert CR McGimpsey WG 《Langmuir : the ACS journal of surfaces and colloids》2008,24(9):5140-5145
Multilayered photocurrent generating thin films were fabricated by templated noncovalent assembly via stepwise assembly of molecular components. Each of films I-IV contained an underlying self-assembled monolayer (SAM) consisting of an alkanethiol linked covalently to a 2,6-dicarboxypyridine ligand that served as a binding site for attaching additional molecular components. The SAM subsequently was functionalized by sequential deposition of Cu(II), Co(II), or Fe(III) ions followed by a variety of substituted 2,6-dicarboxypyridine ligands as a means to incorporate one or more layers of pyrene chromophores into the film. The films were characterized by contact angle measurements, ellipsometry, grazing incidence IR, cyclic voltammetry, and impedance spectroscopy after deposition of each layer, confirming the formation of ordered, stable layers. Following incorporation into a three-electrode system, photoexcitation resulted in the generation of a cathodic photocurrent in the presence of methyl viologen and an anodic photocurrent in the presence of triethanolamine. Using this strategy, systems were fabricated that produced up to 89 nA/cm(2) of reproducible photocurrent. 相似文献