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51.
The kinetics of hydrolysis of Cu(II)-salicylamide complex have been studied in sodium hydroxide solution (0.5 to 2.5M). The observed pseudo-first-order rate constants vary according to the empirical equation 1/??obs = B1 + B2/[ōH] up to 2.0 M sodium hydroxide concentration. The mechanism of base-catalyzed hydrolysis has been proposed and it is concluded that the reaction proceeds by the interaction of complex with the nucleophile, forming tetrahedral intermediate which then breaks down to products. The rate equation has been derived. Thermodynamic parameters have also been reported.  相似文献   
52.
Iqbal  Mohammad S.  Mughal  Mohammad S.  Arif  Raazia  Fatima  Sadia  Sher  Muhammad 《Chromatographia》2009,70(11):1659-1663

This papers describes the in vitro interaction of copper(II) acetylsalicylate and copper(II) salicylate with genomic DNA isolated from human blood. The two drug substances were found to bind to DNA after incubation with whole blood over night. Bonding was confirmed by detection of separated DNA electrophoresis bands for copper, copper(II) acetylsalicylate, copper(II) salicylate, acetylsalicylic acid and salicylic acid. Drug–DNA interactions were observed during electrophoresis in the form of fragmentation by formation of two bands when compared to controls. Gel permeation chromatography parameters also confirmed the occurrence of fragmentation. The use of gel permeation chromatography parameters as a measure of fragmentation of DNA is discussed. The fragmentation of genomic DNA after incubation with copper(II) acetylsalicylate and copper(II) salicylate suggested that these drug substances might be responsible for cytotoxicity in vivo.

  相似文献   
53.
In laser cutting of sheet metals, thermal stresses are developed in the region of the cutting section. Depending on the cutting conditions and substrate material properties, the thermal stress levels can attain high values. In the present study, thermal stress developed in the region of the laser cut edges is modeled and temperature as well as stress fields are predicted. Temperature predictions are validated through the experimental results. It was found that the temporal variation of the maximum temperature along y-axis follows the laser heating source. However, temporal variation of von-Mises stress deviates slightly from the temporal variation of temperature along the cutting direction. Increase in scanning speed enhances the von-Mises stress levels due to the attainment of high temperature gradients in the substrate material.  相似文献   
54.
We study the coupling of a tetraquark system to an exchanged meson-meson channel, using a pure gluonic theory based four-quark potential matrix model which is known to fit well a large number of data points for lattice simulations of different geometries of a four-quark system. We find that if this minimal-area-based potential matrix replaces the earlier used simple Gaussian form for the gluon field overlap factor f in its off-diagonal terms, the resulting T -matrix and phase shifts develop an angle dependence whose partial-wave analysis reveals D wave and higher angular-momentum components in it. In addition to the obvious implications of this result for the meson-meson scattering, this new feature indicates the possibility of orbital excitations influencing properties of meson-meson molecules through a polarization potential. We have used a formalism of the resonating group method, treated kinetic energy and overlap matrices on model of the potential matrix, but decoupled the resulting complicated integral equations through the Born approximation. In this exploratory study we have used a quadratic confinement and not included the spin dependence; we also used the approximation of equal constituent quark masses.  相似文献   
55.
We propose some extensions of the quark potential model to hybrids, fit them to the lattice data and use them for the purpose of calculating the masses, root mean square radii and wave functions at the origin of the conventional and hybrid charmonium mesons. We treat the ground and excited gluonic field between a quark and an antiquark as in the Born-Oppenheimer expansion, and use the shooting method to numerically solve the required Schrödinger equation for the radial wave functions; from these wave functions we calculate the mesonic properties. For masses we also check through a Crank Nichelson discretization. For hybrid charmonium mesons, we consider the exotic quantum number states with J PC = 0+?, 1?+ and 2+?. We also compare our results with the experimentally observed masses and theoretically predicted results of the other models. Our results have implications for scalar form factors, energy shifts, magnetic polarizabilities, decay constants, decay widths and differential cross-sections of conventional and hybrid mesons.  相似文献   
56.
We present systematic studies that comprise phase connectivity and dielectric, multiferroic (MF) and magnetoelectric (ME) properties of (x) Ni0.8Co0.2Fe2O4+(1−x) Pb(Mg1/3Nb2/3)0.67Ti0.33O3 [where x=0.15, 0.30 and 0.45] ME composites prepared by conventional solid-state reaction method. Scanning electron microscopic images of the composites predict different types of connectivity schemes viz 3-0, 3-1 and 3-3. The phase transition temperature of PMN-PT is independent of Ni0.8Co0.2Fe2O4 content. Room temperature P-E and M-H loops indicate the simultaneous existence of ferroelectric/magnetic ordering. In order to study the possibility of monitoring electrical ordering by means of a magnetic field, ME measurements were carried out. The composition-dependent phase connectivity was well co-related to formation of percolation path and inturn magnetoelectric output.  相似文献   
57.
We present a class of interacting nonlocal quantum field theories, in which the CPT invariance is violated while the Lorentz invariance is present. This result rules out a previous claim in the literature that the CPT violation implies the violation of Lorentz invariance. Furthermore, there exists the reciprocal of this theorem, namely that the violation of Lorentz invariance does not lead to the CPT violation, provided that the residual symmetry of Lorentz invariance admits the proper representation theory for the particles. The latter occurs in the case of quantum field theories on a noncommutative space–time, which in place of the broken Lorentz symmetry possesses the twisted Poincaré invariance. With such a CPT-violating interaction and the addition of a C-violating (e.g., electroweak) interaction, the quantum corrections due to the combined interactions could lead to different properties for the particle and antiparticle, including their masses.  相似文献   
58.
In this paper we find the formula of connections under which an almost complex structure is covariantly constant. These types of connections on anti-Kähler–Codazzi manifolds are described. Also, twin metric-preserving connections are analyzed for quasi-Kähler manifolds. Finally, anti-Hermitian Chern connections are investigated.  相似文献   
59.
We provide a simple physical proof of the reciprocity theorem of classical electrodynamics in the general case of material media that contain linearly polarizable as well as linearly magnetizable substances. The excitation source is taken to be a point-dipole, either electric or magnetic, and the monitored field at the observation point can be electric or magnetic, regardless of the nature of the source dipole. The electric and magnetic susceptibility tensors of the material system may vary from point to point in space, but they cannot be functions of time. In the case of spatially non-dispersive media, the only other constraint on the local susceptibility tensors is that they be symmetric at each and every point. The proof is readily extended to media that exhibit spatial dispersion: For reciprocity to hold, the electric susceptibility tensor χE_mn that relates the complex-valued magnitude of the electric dipole at location rm to the strength of the electric field at rn must be the transpose of χE_nm. Similarly, the necessary and sufficient condition for the magnetic susceptibility tensor is χM_mn = χTM_nm.  相似文献   
60.
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