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排序方式: 共有229条查询结果,搜索用时 31 毫秒
81.
Bilge Taner Pervin Deveci Emine ?zcan Ali Osman Solak 《Journal of inclusion phenomena and macrocyclic chemistry》2012,74(1-4):391-396
A new calix[4]pyrrole functionalized vic-dioxime, 3-(4-methyl-9,9,14,14,19,19-hexaethylcalix[4]pyrrole)benzoaminoglyoxime (LH2) was synthesized from anti-chloroglyoxime and 3-aminophenyl-calix[4]pyrrole at room temperature. The mononuclear complexes {nickel(II), copper(II) and cobalt(II)} of this vic-dioxime ligand were prepared and their structures were confirmed by elemental analysis, IR and UV–Vis spectrophotometry, magnetic susceptibility; the MS, 1H and 13C NMR spectra of the LH2 ligand and its Ni(II) complex were also recorded. The experimental results indicated that the ligand:metal ratio was 2:1 in the cases of Ni(II), Cu(II) and Co(II) complexes as is with most vic-dioximes. Electrochemical properties of the ligand, and its complexes were investigated in DMSO solution by cyclic voltammetry at 200?mV?s?1 scan rate. 相似文献
82.
Gallina ME Baytekin B Schalley C Ceroni P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(5):1528-1535
Two rotaxanes with benzyl ether axles and tetralactam wheels were synthesized through an anion template effect. They carry naphthalene chromophores attached to the stopper groups and a pyrene chromophore attached to the wheel. The difference between the two rotaxanes is represented by the connecting unit of the naphthyl chromophore to the rotaxane axle: a triazole or an alkynyl group. Both rotaxanes exhibit excellent light-harvesting properties: excitation of the naphthalene chromophores is followed by energy transfer to the pyrene unit with efficiency higher than 90% in both cases. This represents an example of light-harvesting function among chromophores belonging to mechanically interlocked components, that is, the axle and the wheel of the rotaxanes. 相似文献
83.
Poly(2-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl) (SNS) acetic acid) was electrochemically deposited on graphite electrodes and functionalized with lysine (Lys) amino acid and poly(amidoamine) derivatives (PAMAM?G2 and PAMAM?G4) to investigate their matrix properties for biosensor applications. Glucose oxidase (GOx) was immobilized onto the modified surface as the model enzyme. X-Ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were used to report the surface properties of the matrices in each step of the biosensor construction. The biosensors were characterized in terms of their operational and storage stabilities and the kinetic parameters (K and I(max)). Three new glucose biosensors revealed good stability, featuring low detection limits (19.0 μM, 3.47 μM and 2.93 μM for lysine-, PAMAM?G2- and PAMAM?G4-functionalized electrodes, respectively) and prolonged the shelf lives (4, 5, and 6 weeks for Lys-, PAMAM?G2- and PAMAM?G4-modified electrodes, respectively). The proposed biosensors were tested for glucose detection on real human blood serum samples. 相似文献
84.
Erhan Albayrak 《Phase Transitions》2013,86(7):541-550
The distinct hysteresis loops (HLs) of ferromagnetic/antiferromagnetic (FM/AFM) two-layer Bethe lattice with the Ising spins of the top layer having only FM interactions and the bottom ones having only AFM interactions with the interlayer coupling is either FM or AFM type are studied by using a pairwise approach. The sublattice magnetizations are studied by increasing and decreasing the external magnetic field (H) to obtain the HLs. The shapes of the HLs are strongly dependent on the competitions among the system parameters and on the phase configurations. The HLs are formed only when the AFM-type interactions are involved. The small loops of hysteresis are also formed because of the reentrant behavior in the FM region. 相似文献
85.
Composites of poly(vinyl chloride) (PVC) filled with micron‐ and nanosized calcium carbonate (CaCO3) particles were prepared by solution blending. The influences of particle size and CaCO3 content on the microstructure and mechanical properties of the PVC composites were investigated by means of polarized optical microscopy and mechanical testing. The polarized optical microscope images revealed that nanosized CaCO3 particles were more agglomerated than micron‐sized CaCO3 particles and the amount of agglomerates increased with increasing particle content. PVC/CaCO3‐0.22 composites (PVC nanocomposite filled with 220‐nm‐particle‐sized CaCO3) 5 phr CaCO3 content had the maximum tensile strength. The Young's modulus of all composites increased with increasing particle content. The energy at break of all composites showed a decreasing trend as a function of CaCO3 content and varied with particle size. 相似文献
86.
Integrated production scheduling and distribution planning in dairy supply chain by hybrid modelling
In this paper we address the production scheduling and distribution planning problem in a yoghurt production line of the multi-product dairy plants. A mixed integer linear programming model is developed for the considered problem. The objective function aims to maximize the benefit by considering the shelf life dependent pricing component and costs such as processing, setup, storage, overtime, backlogging, and transportation costs. Key features of the model include sequence dependent setup times, minimum and maximum lot sizes, overtime, shelf life requirements, machine speeds, dedicated production lines, typically arising in the dairy industry. The model obtains the optimal production plan for each product type, on each production line, in each period together with the delivery plan. The hybrid modelling approach is adopted to explore the dynamic behavior of the real world system. In the hybrid approach, operation time is considered as a dynamic factor and it is adjusted by the results of the simulation and optimization model iteratively. Thus, more realistic solutions are obtained for the scheduling problem in yoghurt industry by using the iterative hybrid optimization-simulation procedure. The efficiency and applicability of the proposed model and approach are demonstrated in a case study for a leading dairy manufacturing company in Turkey. 相似文献
87.
Baytekin B Baytekin HT Grzybowski BA 《Journal of the American Chemical Society》2012,134(17):7223-7226
Although it is known that contact-electrified polymers can drive chemical reactions, the origin of this phenomenon remains poorly understood. To date, it has been accepted that this effect is due to excess electrons developed on negatively charged surfaces and to the subsequent transfer of these electrons to the reactants in solution. The present study demonstrates that this view is incorrect and, in reality, the reactions are driven by mechanoradicals created during polymer-polymer contact. 相似文献
88.
89.
Mustafa Odabaolu idem Albayrak Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(4):o240-o242
Molecules of the title compound, C8H9NO2, are linked into sheets by a combination of C—H·N, O—H·N and O—H·O hydrogen bonds and C—H·π interactions. The hydrogen bonds are arranged as described by the graph‐set ring notations R22(7) and R33(5), and a C8 chain motif. There are two planar symmetry‐independent molecules in the asymmetric unit, with a dihedral angle of 19.24 (5)° between their least‐squares mean planes. 相似文献
90.
Orhan Büyükgüngr Mustafa Odabaolu idem Albayrak Peter Lnnecke 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o470-o472
The title complex, 2C5H7N2+·C4H2O42−·C4H4O4, contains cyclic eight‐membered hydrogen‐bonded rings involving 2‐aminopyridinium and fumarate ions. The fumaric acid molecules and fumarate ions lie on inversion centers and are linked into zigzag chains by O—H⋯O hydrogen bonds. The dihedral angle between the pyridinium ring and the hydrogen‐bonded fumarate ion is 7.60 (4)°. The fumarate anion is linked to the pyridinium cations by intermolecular N—H⋯O hydrogen bonds. The heterocycle is fully protonated, thus enabling amine–imine tautomerization. 相似文献