Hydroxy and methoxy substituted N 1,N 4-diarylidene-S-methylthiosemicarbazone iron(III) and nickel(II) complexes

Template reactions of 2,4-dihydroxy-, 2,5-dihydroxy-, 2-hydroxy-3-methoxy- and 2-hydroxy-4-methoxy-benzaldehyde with methoxy- and hydroxy-substituted salicylaldehyde S-methylthiosemicarbazones in the presence of NiCl₂ and FeCl₃ resulted in the corresponding hydroxy- and methoxy-substituted N¹,N⁴-diarylidene-S-methylthiosemi-carbazone complexes. Characterization of the compounds, [Fe(L)Cl] and [Ni(L)], was accomplished by means of elemental analysis, conductivity and magnetic measurements, i.r. and ¹H-n.m.r. spectra. A systematic trend has been observed for the chemical shift values of the aromatic protons in the spectra of complexes.     

Hydrogen-bonded and π-stacked nickel(II) thiosemicarbazone complexes: Synthesis,spectral and structural studies

Transition Metal Chemistry - Mixed ligand Ni(II) complexes were synthesized from triphenylphosphine and S-methyl- or S-ethyl-isothiosemicarbazone ligands derived from...     

Evidence for symplectic symmetry in Ab initio no-core shell model results for light nuclei

Clear evidence for symplectic symmetry in low-lying states of 12C and 16O is reported. Eigenstates of 12C and 16O, determined within the framework of the no-core shell model using the J-matrix inverse scattering potential with A相似文献   

The -theory of toric manifolds

Toric manifolds, a topological generalization of smooth projective toric varieties, are determined by an -dimensional simple convex polytope and a function from the set of codimension-one faces into the primitive vectors of an integer lattice. Their cohomology was determined by Davis and Januszkiewicz in 1991 and corresponds with the theorem of Danilov-Jurkiewicz in the toric variety case. Recently it has been shown by Buchstaber and Ray that they generate the complex cobordism ring. We use the Adams spectral sequence to compute the -theory of all toric manifolds and certain singular toric varieties.

     

A Dielectric Chirped Layered Mirror for Optical Telecommunication Wavelengths

We describe in this paper a design procedure for omnidirectional high reflectors with wide bandwidths for optical telecommunication bands. From the numerical results achieved by the transfer matrix method, it is found that a partial omnidirectional high-reflector covering the optical telecommunication wavelengths 1.3 and 1.55 μm is obtained for a partially deformed quarter-wave stack air/H(LH)¹⁵/glass by using the tellurium as a material of high refractive index (n _H = 4.6). The partially deformed stack is a periodic system deformed by a power law y = x ^1+k. Here y is the coordinates of the deformed object, x is the coordinates of the periodic stack and k is the coefficient defining the deformation degree. The study of this system leads to an omnidirectional high reflector band covering the optical telecommunication wavelengths 1.3 and 1.55 μm for k = 0.2.     

The effect of parasitic boron doping on P-type piezoresistors

Absolute piezoresistive pressure sensors often use direct wafer bonding of SOI with the etched bulk silicon to provide us with sensitive membranes and sealed cavities. The advantage of such a process is that we can easily obtain a thin, monocrystalline silicon membrane with controlled thickness and a vacuum sealed cavity. However, few works have been reported on the electrical quality of this N-type membrane and its influence on performance of the P-type gauges. The problem of parasitic Boron appearance at the Si/SiO₂ interface was only recently shown in BESOI wafers, but it becomes much more significant when creating the component at the bottom side of the device layer, like in the case of an absolute piezoresistive pressure sensor.     

Two new acridone alkaloids from Glycosmis macrantha

Extraction and chromatographic separation of the extracts of dried stem barks of Glycosmis macrantha lead to isolation of two new acridone alkaloids, macranthanine and 7-hydroxynoracronycine, and a known acridone, atalaphyllidine. The structures of these alkaloids were determined by detailed spectral analysis and also by comparison with reported data.     

Two-dimensional quaternion wavelet transform

In this paper we introduce the continuous quaternion wavelet transform (CQWT). We express the admissibility condition in terms of the (right-sided) quaternion Fourier transform. We show that its fundamental properties, such as inner product, norm relation, and inversion formula, can be established whenever the quaternion wavelets satisfy a particular admissibility condition. We present several examples of the CQWT. As an application we derive a Heisenberg type uncertainty principle for these extended wavelets.     

Soulamarin, a new coumarin from stem bark of Calophyllum soulattri

The extracts of the stem bark of Calophyllum soulattri gave a new pyranocoumarin, soulamarin (1), together with five other xanthones caloxanthone B (2), caloxanthone C (3), macluraxanthone (4), trapezifolixanthone (5) and brasixanthone B (6) one common triterpene, friedelin (7), and the steroidal triterpene stigmasterol (8). The structures of these compounds were established based on spectral evidence (1D and 2D NMR).