Non-isotopic symplectic tori in the same homology class

For any pair of integers and , we construct an infinite family of mutually non-isotopic symplectic tori representing the homology class of an elliptic surface , where is the homology class of the fiber. We also show how such families can be non-isotopically and symplectically embedded into a more general class of symplectic -manifolds.

     

Nickel ion as a template in the synthesis of macrocyclic imine-oxime complexes from carbonyl compounds and o-phenylenediamine

A new series of macrocyclic imine-oxime complexes prepared by template condensation of o-phenylenediamine, phthaldialdehyde, 2,6-diacetylpyridine and dichloroglyoxime in MeOH solution, have been characterized by i.r., electronic spectral data, elemental analyses, conductivity and magnetic susceptibility measurements. In the imine moiety of the complexes, the chloride ions coordinate to the nickel ion. From conductivity measurements, it was shown that the complexes are not all electrolytes. Their thermal behaviour has been studied by the t.g. and d.t.a. analysis. They decompose with loss of the organic ligand and halogen to leave the metal oxide.     

Optical phase cloaking of 700 nm light waves in the far field by a three-dimensional carpet cloak

Transformation optics is a design tool that connects the geometry of space and propagation of light. Invisibility cloaking is a corresponding benchmark example. Recent experiments at optical frequencies have demonstrated cloaking for the light amplitude only. In this Letter, we demonstrate far-field cloaking of the light phase by interferometric microscope-imaging experiments on the previously introduced three-dimensional carpet cloak at 700 nm wavelength and for arbitrary polarization of light.     

A review of recent research on green road freight transportation

Road freight transportation is a major contributor to carbon dioxide equivalent emissions. Reducing these emissions in transportation route planning requires an understanding of vehicle emission models and their inclusion into the existing optimization methods. This paper provides a review of recent research on green road freight transportation.     

Yolk-Shell Nanostars@Metal Organic Frameworks as Molecular Sieves for Optical Sensing and Catalysis

Hybrid composites between nanoparticles and metal organic frameworks (MOFs) have been described as optimal materials for a wide range of applications in optical sensing, drug delivery, pollutant removal or catalysis. These materials are usually core-shell single- or multi-nanoparticles, restricting the inorganic surface available for reaction. Here, we develop a method for the preparation of yolk-shells consisting in a plasmonic gold nanostar coated with MOF. This configuration shows more colloidal stability, can sieve different molecules based on their size or charge, seems to show some interesting synergy with gold for their application in photocatalysis and present strong optical activity to be used as SERS sensors.     

Synthesis of Schiff and Mannich bases of isatin derivatives with 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones

Ethyl imidate hydrochlorides 1 were prepared by passing HCl gas through solutions of substituted benzyl cyanides and absolute ethanol. Ethoxycarbonylhydrazones 2 were synthesized from the reaction of compounds 1 with ethyl carbazate. Treatment of 2 with hydrazine hydrate leads to the formation of substituted 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones 3. Isatin and 5-chloroisatin were added to 3 to form Schiff bases 4 and N-Mannich bases 5 of these compounds were synthesized by reacting with formaldehyde and piperidine. Their chemical structures were confirmed by means of IR, (1)H- and (13)C-NMR data and by elemental analysis.     

Copolymer formation of 9-(2-(benzyloxy)ethyl)-9H-carbazole and 1-tosyl-1H-pyrrole coated on glassy carbon electrode and electrochemical impedance spectroscopy

In this work, 9-(2-(benzyloxy)ethyl)-9H-carbazole (BzOCz) and 1-tosyl-1H-pyrrole (TsP) monomers were chemically synthesized and characterized by Fourier transform infrared reflectance (FTIR) and proton nuclear magnetic resonance (¹H-NMR) spectroscopy. BzOCz and TsP were electrocoated on glassy carbon electrode (GCE) in various molar fractions (X _TsP?=?0.5, 0.83, 0.91, and 0.98) in 0.1?M sodium perchlorate/acetonitrile. The detailed characterization of poly(BzOCz-co-TsP) was studied by cyclic voltammetry, FTIR-attenuated total reflection spectroscopy and electrochemical impedance spectroscopy (EIS). The effects of different molar fractions during the preparation of modified electrodes were studied by EIS technique. The AC impedance technique was used to determine the capacitive behaviors of modified GCE via Nyquist, Bode magnitude, and Bode phase plots. The highest low frequency capacitance value was obtained as C _LF?=?23.94?μF?cm^?2 for X _TsP?=?0.98. Therefore, synthesized copolymer has more capacitive behavior than its homopolymers, such as C _LF?=?7.5?μF?cm^?2 for poly(BzOCz) and C _LF?=?9.44?μF?cm^?2 for poly(TsP). In order to interpret the AC impedance spectra, R(Q(RW)) electrical equivalent circuit was employed with linear Kramers–Kronig test. A mechanism for electropolymerization has been proposed for copolymer formation.     

Testing a two-state model of nanoconfined liquids: conformational equilibrium of ethylene glycol in amorphous silica pores

Molecular dynamics simulations of the conformational equilibrium of ethylene glycol in roughly cylindrical nanoscale amorphous silica pores are presented and analyzed in the context of a two-state model of confined liquids. This model assumes that an observable property of a confined liquid can be decomposed into a weighted average arising from two subensembles with distinct physical attributes: molecules at the surface and molecules in the interior of the pore. It is further assumed that the molecules in the interior exhibit behavior that is indistinguishable from that of the bulk liquid. However, the present simulation results are not consistent with this two-state model. Neither the assumption of two distinct subensembles nor the assumption that the interior molecules possess bulk-like behavior is supported.     

Monodisperse porous poly(vinyl acetate-co-divinylbenzene) particles by single-stage seeded polymerization: a packing material for reversed phase HPLC

A single-stage swelling and polymerization method was proposed for the synthesis of monodisperse porous poly(vinyl acetate-co-divinylbenzene) [poly(VAc-co-DVB)] particles with different VAc/DVB feed ratios. The particles obtained with the VAc/DVB feed ratio of 50:50 v/v had a narrow pore size distribution exhibiting a sharp peak at 30 nm. Based on this distribution the mean pore size and the specific volume were determined as 12 nm and 1.39 mL/g, respectively. The specific surface area of poly(VAc-co-DVB) particles was found to be 470 m2/g. These properties make poly(VAc-co-DVB) particles a promising support for potential HPLC applications. Poly(vinyl alcohol-co-divinylbenzene) [poly(VA-co-DVB)] particles were then obtained by the basic hydrolysis of poly(VAc-co-DVB) particles. The hydroxyl groups on poly(VA-co-DVB) particles have a suitably reactive functionality for surface grafting or derivatization protocols aiming at synthesizing various HPLC packings. The examination of poly(VA-co-DVB) particles by confocal laser scanning microscopy showed the homogeneous distribution of hydroxyl functionality in the particle interior. As a starting point, the chromatographic performance of plain material, poly(VAc-co-DVB) particles produced with VAc/DVB feed ratio of 50:50 (v/v) was tested by a commonly utilized chromatographic mode, reversed phase chromatography. Poly(VAc-co-DVB) particles were successfully used as packing material in the RP separation of alkylbenzenes with resolutions higher than 1.5. Theoretical plate numbers up to 17 500 plates/m were achieved. No significant change both in the chromatographic resolution and column efficiency was observed with increasing flow rate. The chromatography showed that poly(VAc-co-DVB) particles were a suitable starting material for the synthesis of chromatographic packings for different modes of HPLC.     

Syntheses, crystal structures, spectral and thermal analysis and biological activities of copper(II)-pyridine-2,5-dicarboxylate complexes with 4-methylimidazole, imidazole, and 3,4-dimethylpyridine

In this study, three novel Cu(II)-pyridine-2,5-dicarboxylate (pydc) complexes with 4-methylimidazole (4-Meim), [Cu(pydc)(H₂O)(4-Meim)₂]·H₂O (1), imidazole (im), {[Cu(μ-pydc)(im)₂]·2H₂O}_n (2), and 3,4-dimethylpyridine (dmpy), [Cu(μ-pydc)(H₂O)(dmpy)]_n (3) have been synthesized. Elemental and thermal analyses, magnetic susceptibilities, IR and UV/vis spectroscopic studies have been performed to characterize the complexes. The molecular structures of mononuclear (1) and polynuclear (2 and 3) complexes have been determined by the single crystal X-ray diffraction technique. In 1 and 2, Cu(II) ions have distorted square planer geometry, while 3 has distorted octahedral coordination. The pyridine-2,5-dicarboxylate exhibits three different coordination modes namely bidentate (1), tridentate (2) and tetradentate (3). The complex 1 is further constructed to form three-dimensional framework by hydrogen bonding, C–Hπ and ππ stacking interactions. The adjacent chains of 2 and 3 are then mutually linked via hydrogen bonding, ππ and C–Hπ interactions, which are further assembled to form three-dimensional framework. 1 exhibits the magnetic moment value of 1.70 BM, which corresponds to one of the unpaired electron, while the polynuclear complexes 2 and 3 exhibit 1.58 and 1.46 BM, which is lower than the spin only value for one unpaired electron, indicates to antiferromagnetic effect. The first thermal decomposition process of all the complexes is endothermic dehydration. This stage is followed by partial (or complete) decomposition of the neutral and pydc ligands. In the later stage, the remained organic residue exothermically burns. The final decomposition products which identified by IR spectroscopy were the CuO.