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71.
A novel quadridentate, N2O2 type Schiff base, synthesized from 1,4‐bis‐(o‐aminophenoxy)butane and 2‐hydroxynaphthalin‐1‐carbaldehyde, forms stable complexes with transition metal ions such as Co(II), Cu(II) and Ni(II) in DMF. Microanalytical data, elemental analysis, magnetic measurements, UV‐visible and IR‐spectra as well as conductance measurements were used to confirm the structures. Electrochemical measurements show that metal complexes undergo quasi‐reversible one‐electron redox processes. The voltammetric results also revealed that the CuL complex has the highest electron transfer rate indicating that both the Cu(II) and Cu(I) forms appear in a similar planar configuration, so the electron transfer does not require larger reorganization of the complex. 相似文献
72.
Soboh Rawan S. M. Al-Masoodi Ahmed H. H. Erman Fuad. N. A. Al-Masoodi Ab. H. H. Arof H. Yasin M. Harun S. W. 《Journal of Russian Laser Research》2022,43(2):193-200
Journal of Russian Laser Research - In this paper, we employ a Zinc Phthalocyanine (ZnPc) organic material to construct a saturable absorber (SA) that is used in a laser cavity to generate... 相似文献
73.
74.
F. Doğan M. Ulusoy Ö. F. Öztürk İ. Kaya B. Salih 《Journal of Thermal Analysis and Calorimetry》2009,96(1):267-276
The thermal decomposition kinetics of sterically hindered salen type ligand (L) and its metal complexes [M=Co(II), Ni(II), Cu(II)] were investigated by thermogravimetric analysis. A direct insertion probe-mass spectrometer (DIP-MS)
was used for the characterization of metal complexes of L and all fragmentations and stable ions were characterized. The thermogravimetry and differential thermogravimetry (TG-DTG)
plots of salen type salicylaldimine ligand and complexes showed a single step.
The kinetic analysis of thermogravimetric data was performed by using the invariant kinetic parameter method (IKP). The values
of the invariant activation energy, E
inv and the invariant pre-exponential factor, A
inv, were calculated by using Coats-Redfern (CR) method. The thermal stabilities and activation energies of metal complexes of
sterically hindered salen type ligand (L) were found as Co(II)>Cu(II)>Ni(II)>L and E
Cu>E
Ni>E
Co>L. Also, the probabilities of decomposition functions were investigated. The diffusion functions (D
n) are most probable for the thermal decomposition of all complexes. 相似文献
75.
We report a detailed analysis of the potential energy surface of N-acetyl-l-tryptophan-N-methylamide, (NATMA) both in the gas phase and in solution. The minima are identified using the density-functional-theory (DFT) with the 6-31g(d) basis set. The full potential energy surface in terms of torsional angles is spanned starting from various initial configurations. We were able to locate 77 distinct L-minima. The calculated energy maps correspond to the intrinsic conformational propensities of the individual NATMA molecule. We show that these conformations are essentially similar to the conformations of tryptophan in native proteins. For this reason, we compare the results of DFT calculations in the gas and solution phases with native state conformations of tryptophan obtained from a protein library. In native proteins, tryptophan conformations have strong preferences for the beta sheet, right-handed helix, tight turn, and bridge structures. The conformations calculated by DFT, the solution-phase results in particular, for the single tryptophan residue are in agreement with native state values obtained from the Protein Data Bank. 相似文献
76.
Salih Djilali 《Journal of Applied Analysis & Computation》2019,9(2):638-654
In this paper, we deal with the effect of the shape of herd behavior on the interaction between predator and prey. The model analysis was studied in three parts. The first, The
analysis of the system in the absence of spatial diffusion and the time delay, where the local stability of the equilibrium states, the existence of Hopf bifurcation have been investigated. For the second part, the spatiotemporal dynamics introduce by self diffusion was determined, where the existence of Hopf bifurcation, Turing driven instability, Turing-Hopf bifurcation point have been proved. Further, the order of Hopf bifurcation points and regions of the stability of the non trivial equilibrium state was given. In the last part of the paper, we studied the delay effect on the stability of the non trivial equilibrium, where we proved that the delay can lead to the instability of interior equilibrium state, and also the existence of Hopf bifurcation. A numerical simulation was carried out to insure the theoretical results. 相似文献
77.
Erman Çineli 《Archiv der Mathematik》2018,111(6):647-656
In this paper we connect algebraic properties of the pair-of-pants product in local Floer homology and Hamiltonian dynamics. We show that for an isolated periodic orbit, the product is non-uniformly nilpotent and use this fact to give a simple proof of the Conley conjecture for closed manifolds with aspherical symplectic form. More precisely, we prove that on a closed symplectic manifold, the mean action spectrum of a Hamiltonian diffeomorphism with isolated periodic orbits is infinite. 相似文献
78.
Jumat Salimon Nadia Salih Emad Yousif Ayad Hameed Ayad Kreem 《Arabian Journal of Chemistry》2010,3(4):205-210
In the present study a new acridone derivatives were synthesized. The newly synthesized compounds were characterized by IR, NMR and C, H, N, S analyses. All newly synthesized compounds were screened for their antibacterial (Staphylococcus aureus, Streptococcus viridans and Escherichia coil) and antifungal (Gibberela, Cercospora arachidicola, Physolospora piricola and Fusarium oxysporum) studies. The results revealed that all synthesized compounds have a significant biological activity against the tested microorganisms. 相似文献
79.
Salih S. Al-Juaid Colin Eaborn Paul D. Lickiss J. David Smith Kayumars Tavakkoli Alexander D. Webb 《Journal of organometallic chemistry》1996,510(1-2):143-151
Mercury compounds of the types HgR1R (R1 = C(SiMe3)3; R = Me, iPr, Bu, tBu or Ph) and HgR2R(R2 = C(SiMe2Ph)3; R = Me, Bu, CH2Ph or Ph) have been prepared. Those containing R1 were made by reactions of the bromides HgR1Br with the Grignard reagents MgRX, and those containing R2 by reaction of HgR2Cl with LiR or, for R = CH2Ph, with Mg(CH2Ph)Cl. Replacement of one R group in HgR2 by the bulky R1 or R2 group leads to a large increase in thermal stability, a marked shift in the 199Hg resonance to lower frequency and an increase in the coupling constant 1J(13C---199Hg) for the Hg---R bond. The compound HgR2Cl does not react further with LiR2 in tetrahydrofuran, but with LiR1 gives HgR1R2; the arrangement of the SiMe2Ph groups in the latter in solution in CH2C12 at low temperature appears to be different from that in the solid. 相似文献
80.
Predicting protein structures from their amino acid sequences is a problem of global optimization. Global optima (native structures) are often sought using stochastic sampling methods such as Monte Carlo or molecular dynamics, but these methods are slow. In contrast, there are fast deterministic methods that find near-optimal solutions of well-known global optimization problems such as the traveling salesman problem (TSP). But fast TSP strategies have yet to be applied to protein folding, because of fundamental differences in the two types of problems. Here, we show how protein folding can be framed in terms of the TSP, to which we apply a variation of the Durbin-Willshaw elastic net optimization strategy. We illustrate using a simple model of proteins with database-derived statistical potentials and predicted secondary structure restraints. This optimization strategy can be applied to many different models and potential functions, and can readily incorporate experimental restraint information. It is also fast; with the simple model used here, the method finds structures that are within 5-6 A all-Calpha-atom RMSD of the known native structures for 40-mers in about 8 s on a PC; 100-mers take about 20 s. The computer time tau scales as tau approximately n, where n is the number of amino acids. This method may prove to be useful for structure refinement and prediction. 相似文献