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41.
Gönül Yenilmez Çiftçi Elif ?enkuytuEsra Tanr?verdi Eçik Adem K?l?çFatma Yuksel 《Polyhedron》2011,30(13):2227-2236
New 1,3-propanediaminocyclotriphosphazene derivatives (7-17) were synthesized from the reactions of spiro-1,3-propanediaminocyclotriphosphazene, N3P3Cl4[NH(CH2)3NH] (1) with the cyclopropanemethylamine (2), cyclohexylamine (3), pyrrolidine (4) cyclohexanol (5), cyclopropylmethanol (6). The structures of the novel compounds (7-17) were characterized by elemental analysis, mass spectrometry, 1H and 31P NMR spectroscopy. The molecular structures of 8, 12 and 13 were determined by X-ray crystallography. The structures of all these three compounds are in the monoclinic crystal system; compounds 8 and 12 have the P21/c space group while compound 13 has the P21/n space group. The ring conformation of the cyclotriphosphazene and other external rings were investigated based on the X-ray crystal structures. 相似文献
42.
S. R. Garaeva Ahmet Alper Aydin Adnan Aydin Bahattin Yalçin P. A. Fatullaeva A. A. Medzhidov 《Russian Journal of Applied Chemistry》2010,83(1):97-101
Structure of products formed in polyethylene oxidation by nitric acid was studied by NMR, IR, and electronic absorption spectroscopies
and derivatography. 相似文献
43.
Aydin Tavman Serkan Ikiz A. Funda Bagcigil N. Yakut Özgür Seyyal Ak 《Russian Journal of Inorganic Chemistry》2010,55(2):215-222
2-Methyl-6-(5-H-methyl-chloro-nitro-1H-benzimidazol-2-yl)-phenols( HL
x
:x= 1-4)ligands and HL1 complexes with Fe(NO3)3, Cu(NO3)2, AgNO3, Zn(NO3)2 have been synthesized and characterized. The structures of the compounds were confirmed on the basis of elemental analysis,
molar conductivity, magnetic moment, FT-IR, 1H-and 13C-NMR. Antibacterial activity of the free ligands, their hydrochloride salts and the complexes were evaluated using the disk
diffusion method in dimethyl sulfoxide as well as the minimum inhibitory concentration dilution method, against nine bacteria.
While HL1 ligand has not any activity, it’s Ag(I) complex show antibacterial effect toward almost to all the bacteria. Zn(II) complex
has antibacterial effect on especially K. pneumoniae, S. epidermidis and S. aureus bacteria. 相似文献
44.
The large ring cyclodextrins (with more than 8 glucose units) existence was first described in the 1950s. Because of their hard purification and low yield, these molecules were little studied until recently. Since large ring cyclodextrins have unique structures compared to α-, β- and γ-cyclodextrin, they could offer new opportunities for specific host-guest complex and thus enlarge the area of cyclodextrin applications. This paper gives a literature survey regarding the synthesis, the purification and the applications of cyclodextrins containing more than eight glucose units. 相似文献
45.
Fatma Başak Aydemir Akın Günay Figen Öztoprak Ş. İlker Birbil Pınar Yolum 《Journal of Global Optimization》2013,57(2):499-519
This paper proposes the use of multiagent cooperation for solving global optimization problems through the introduction of a new multiagent environment, MANGO. The strength of the environment lays in its flexible structure based on communicating software agents that attempt to solve a problem cooperatively. This structure allows the execution of a wide range of global optimization algorithms described as a set of interacting operations. At one extreme, MANGO welcomes an individual non-cooperating agent, which is basically the traditional way of solving a global optimization problem. At the other extreme, autonomous agents existing in the environment cooperate as they see fit during run time. We explain the development and communication tools provided in the environment as well as examples of agent realizations and cooperation scenarios. We also show how the multiagent structure is more effective than having a single nonlinear optimization algorithm with randomly selected initial points. 相似文献
46.
In this study, neutron-emission spectra produced by (n, xn) reactions for some structural fusion materials as 27Al, 51V, 52Cr, 55Mn, and 56Fe have been investigated by a neutron beam up to 16 MeV. Multiple preequilibrium mean-free-path constant from internal transition
and the preequilibrium and equilibrium level-density parameters have been investigated for some (n, xn) neutron-emission spectra calculated in this study. Preequilibrium neutron-emission spectra were calculated by using new-evaluated
hybrid model and geometry-dependent hybrid model, full-exciton model, and cascade-exciton model. The reaction equilibrium
component was calculated by Weisskopf-Ewing model. The obtained results have been discussed and compared with the available
experimental data and found agreement with each other.
The text was submitted by the authors in English. 相似文献
47.
Using Breit-Wigner resonance relation,bounds on the magnetic moment of the tau-neutrino are calculated through the reaction e+e-→v(v)γ at the neutral boson pole in the framework of a superstringinspired E6 model which has one extra low-energy neutral gauge boson and a LRSM. 相似文献
48.
Eker F Cao X Nafie L Schweitzer-Stenner R 《Journal of the American Chemical Society》2002,124(48):14330-14341
We have measured the band profile of amide I in the infrared, isotropic, and anisotropic Raman spectra of L-alanyl-D-alanyl-L-alanine, acetyl-L-alanyl-L-alanine, L-vanyl-L-vanyl-L-valine, L-seryl-L-seryl-L-serine, and L-lysyl-L-lysyl-L-lysine at acid, neutral, and alkaline pD. The respective intensity ratios of the two amide I bands depend on the excitonic coupling between the amide I modes of the peptide group. These intensity ratios were obtained from a self-consistent spectral decomposition and then were used to determine the dihedral angles between the two peptide groups by means of a recently developed algorithm (Schweitzer-Stenner, R. Biophys. J. 2002, 83, 523-532). The validity of the obtained structures were checked by measuring and analyzing the vibrational circular dichroism of the two amide I bands. Thus, we found two solutions for all protonation states of trialanine. Assuming a single conformer, one obtains a very extended beta-helix-like structure. Alternatively, the data can be explained by the coexistence of a 3(1)(PII) and a beta-sheet-like structure. Acetyl-L-alanyl-L-alanine exhibits a structure which is very similar to that obtained for trialanine. The tripeptide with the central D-alanine adopts an extended structure with a negative psi and a positive phi angle. Trivaline and triserine adopt single beta(2)-like structures such as that identified in the energy landscape of the alanine dipeptide. Trilysine appears different from the other investigated homopeptides in that it adopts a left-handed helix which at acid pD is in part stabilized by hydrogen bonding between the protonated carboxylate (donor) and the N-terminal peptide carbonyl. Our result provides compelling evidence for the capability of short peptides to adopt stable structures in an aqueous solution, which at least to some extent reflect the intrinsic structural propensity of the respective amino acids in proteins. Furthermore, this paper convincingly demonstrates that the combination of different vibrational spectroscopies provides a powerful tool for the determination of the secondary structure of peptides in solution. 相似文献
49.
In this correspondence, micro-genetic algorithm (MGA) application results for optimizing the performance of electronic feedback of a laser diode are presented. The goal of optimization is to find the maximum bandwidth of the laser diode with electronic feedback used in fiber optic digital communication. A numerical analysis of the system theory of the single-mode laser diode to obtain numerical results of the gain, the pulse response, and the harmonic distortion for electronic feedback is also presented. The dependence of the system gain on the feedback gain and delay is examined. The pulse response is studied and it is shown that a transmission rate over 1 Gbyte/s can be achieved. 相似文献
50.
Of the chloro-substituted benzoic acids, the 2-chloro and 2,4-dichloro compounds yield higher effective molar absorptivities than benzoic acid does in the Rhodamine B-benzene extractive spectrophotometric procedure for determination of uranium(VI). Carbonyl compounds (especially acetone) in the organic phase enhance the extraction of the ion associate. The stoichiometry of the complexes has been determined, and a method of computing the extraction constants of the ion-associates developed. A spectrophotometric method for determining uranium in the presence of interfering ions has been designed. 相似文献