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41.
42.
Ismail Ercan Filiz Ercan Cengiz Arc Orhan Atakol 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):m137-m138
A new tetranuclear CuII–HgII–HgII–CuII complex, [Cu2Hg2Cl4(C18H18N2O2)2], has been prepared by means of a copper complex found in the literature. The molecular structure of this complex was determined by X‐ray diffraction and the Cu–Hg–Hg–Cu chain was seen to be non‐linear. The change in magnetic susceptibility with temperature was recorded for this complex and observed to abide by the Curie–Weiss law. The coordination around the HgII ions is square pyramidal. The Cu?Hg bridging distance is 3.5269 (7) Å. 相似文献
43.
Enantioselective Brønsted acid catalyzed transfer hydrogenation: organocatalytic reduction of imines 总被引:1,自引:0,他引:1
The first enantioselective Br?nsted acid catalyzed reduction of imines has been developed. This new organocatalytic transfer hydrogenation of ketimines with Hantzsch dihydropyridine as the hydrogen source offers a mild method to various chiral amines with high enantioselectivity. The stereochemistry of the chiral amines can be rationalized by a stereochemical model derived from an X-ray crystal structure of a chiral BINOL phosphate catalyst. [reaction: see text] 相似文献
44.
Scrap car tyre particles can be used as filler or toughening agent in rigid epoxy matrices if the resultant interface is adequate. The objective of this work was to investigate the effects of use of different silane coupling agents (SCAs) to improve the interface between the epoxy resin and recycled rubber particles. For this purpose, seven different SCA were used to modify surfaces of the rubber particles. After the preparation of epoxy-rubber specimens, tensile Charpy impact and plane-strain fracture toughness tests were conducted. Mechanical tests and fractographic studies revealed that some of the SCA can improve of the interface between the epoxy matrix and the rubber particles leading to increases in strength while slight decreases in toughness of the samples. 相似文献
45.
An experimental investigation of the effect of pressure on shape memory behavior of Fe–32%Mn–6%Si–3%Cr alloy was undertaken. There are significant differences in the Gibbs free energy, dislocation density and transformation temperatures of the alloy due to applied pressure. 相似文献
46.
Poly(crotonic acid-co-2-acrylamido-2-methyl-1-propanesulfonic acid) [P(CrA-co-AMPS)] (44.22:55.78) copolymer was prepared in N,N-dimethylformamide solution using the benzoyl peroxide (Bz2O2) as initiator. Cu(II), Ni(II) and Co(II) chelates of the copolymer were prepared and the formation constants of each complex were determined by the mole-ratio method using UV-vis spectroscopy. UV-vis studies showed that the complex formation tendency increased in the followed order: Cu(II) > Ni(II) > Co(II). The copolymer and its metal chelates were characterized by FTIR, TGA, X-ray diffraction and SEM analysis. Also, in vitro antimicrobial activity of the polymers were tested on various bacteria, and yeast. 相似文献
47.
The temperature-dependent phase diagrams of the spin-3/2 Ising model on a two-layer Bethe lattice with ferromagnetic (FM)/antiferromagnetic (AFM) intra-layer and either FM or AFM type inter-layer interactions are investigated under a constant magnetic field (H) and in the presence of a crystal field (D) by using exact recursion equations in a pairwise approach for coordination numbers q=3,4 and 6, in detail. In the light of the ground-state (GS) phase diagrams, the temperature-dependent phase diagrams of the model are obtained by studying the thermal variations of the order parameters, response functions and free energy. Then, they are illustrated on the (kT/J1,J3/J1) and (kT/J1,J2/J1) planes for the given system parameters. It is observed that the system exhibits first- and second-order phase transitions for all q values, and hence, in some cases, tricritical points. The existence of critical-end points and that of isolated points are also observed. The re-entrant behavior owes its presence to the two Néel temperatures, TN, that are present for all q. 相似文献
48.
M.Cengiz Dökmeci 《International Journal of Solids and Structures》1974,10(4):401-409
This paper presents a higher order, linear theory of piezoelectric crystal bars as in the same spirit as that of Mindlin. First, a power series representation in aerial coordinates is employed for both the mechanical displacement and electric potential fields. Next, with the help of a variational theorem deduced from Hamilton's principle, together with these series, the theory is established consistently. A hierarchy of 1-dimensional approximate equations of motion, charge equations of electrostatics, initial and boundary conditions, strain-displacement and electric field-electric potential relations, and macroscopic constitutive equations constitutes the theory, and it governs all the types of motions of piezoelectric crystal bars of uniform cross-section. Further, special cases of interest are pointed out. The solutions of the initial mixed boundary-value problems defined by this theory are proven to be unique. 相似文献
49.
Cengiz Arıcı Dinçer Ülkü Mecit Aksu Orhan Atakol 《Journal of chemical crystallography》2003,33(11):825-829
The title compound, forms crystals which are the orthorhombic system, space group P2
12121, with unit cell dimensions a = 10.3928(12) Å, b = 14.6298(13) Å, c = 15.9514(11) Å, V = 2425.3(4) Å3. The cell contains four molecules. The structure is a heteronuclear dimeric complex with ZnII and CdII ions. The coordination around the ZnII ion is distorted square–pyramid and the CdII ion is distorted tetrahedral coordination. The Zn·sCd distance is 3.3594(7) Å. 相似文献
50.
Cengiz Durucu Muzaffer Kanlikama Semih Mumbuc Yildirim Bayazit Kemal Bakir Erkan Karatas 《Journal of voice》2007,21(5):632-639
Vocal cord paralysis is a disease that can cause voice disability and aspiration problems. Expanded polytetrafluoroethylene (ePTFE; Gore-Tex) has been widely used in cardiovascular and plastic surgery; however, its biocompatibility and safety have not been established precisely in the larynx. In this study, the biocompatibility and safety of ePTFE used in vocal cord medialization in the rabbit larynx were assessed. Type 1 thyroplasty with Gore-Tex was performed on one side of the larynx in eight rabbits. A sham procedure was applied on the contralateral side of their larynx. The rabbits were sacrificed after 6 months, and macroscopic and microscopic evaluations and comparisons were performed. No significant inflammatory response to Gore-Tex or displacement of the implant was seen. There was only a tiny fibrotic capsule surrounding the material in each specimen. Intense eosinophilic cell infiltration was seen surrounding one rabbit specimen. Gore-Tex seems to be a biocompatible, stable, and reversible material that can be safely used in laryngeal framework surgery. 相似文献