Coordination properties of vic-isonitrosoimines in their copper (II) and palladium (II) complexes

Preparation and structural characterization of palladium (II) complexes of ligands III-V and copper (II) complexes of III are reported. The elemental analyses of the complexes show that the metal: ligand ratio is 1:2. The electrical conductance in acetone shows the non-electrolytic nature of the complexes. The diamagnetic character suggests a gross square-planar geometry for the palladium (II) complexes. Copper (II) complexes are paramagnetic with¼eff.～1·90 B.M. Spectral data suggest that in all the complexes the ligand coordinates to the metal (II) symmetrically through isonitroso-nitrogen and imine-nitrogen, forming a five membered chelate ring. Amine-exchange reactions of the complexes are discussed and compared on the basis of their structures.     

Isoxazolo (7,8 -d) flavones

A few isoxazolo (7, 8-d) flavones have been synthesised from 7-hydroxy-8-carbonyl flavones by preparing the oximes and cyclising them with sulphuric acid. The ultraviolet, infrared and mass spectra of some of these compounds have been recorded. The antibacterial activity of these derivatives has also been evaluated.     

Type (II) regions between curves of the Fucik spectrum

The Fucik spectrum for a semilinear problem with asymptotic linearities has been shown to consist, at least locally, of curves emanating from a sequence of points in the plane. Regions between curves emanating from different points (referred to as type (I) regions in this paper) have a different nature than those between curves emanating from the same point (referred to as type (II) regions). Problems for which asymptotic limits fall in regions of type (I) have been solved by several authors, but not those for which the limits fall in a type (II) region. In the present paper we solve problems in which the asymptotic limits fall in type (II) regions. Received March 5, 1996     

Polarography of cobalt (II) in water and 50% methanol

The polarographic behaviour of cobalt (II) in water and 50% methanol in the presence of various supporting electrolytes has been studied. The kinetic parameters and activation energy for the electrode process have been evaluated and compared. The results have been discussed on the basis of selective hydration of cobaltous ion at the electrode surface.     

Spectrophotometric studies of copper (II)—bis-2-pyridyl glycol complex

An aqueous solution ofbis-2-pyridyl glycol forms a deep blue water-soluble complex with an aqueous solution of copper (II) salts. The complex has an absorption maximum at 600–650 mµ between pH range 3·0–8·7. The complex is stable for four days and obeys Lambert-Beer’s law in the concentration range of 5·08–50·80 ppm. of copper (II) in solution. The optical density of the complex remains constant between pH 3·8–5·9. The molar composition as determined by the method of continuous variation and by the slope ratio method has been found to be 1:1. The limits of interference due to some foreign ions during the estimation of copper (II) have been determined.     

Synthesis of some chromono (6, 7) oxazoles and their physiological activity

The synthesis of a few chromono (6, 7) oxazoles has been carried out by condensing 6-amino-8-bromo-7-hydroxy-2-methyl chromone with various aromatic aldehydes in nitrobenzene medium. The ultraviolet and infrared spectral characteristics of these compounds have been described. A study of antibacterial and antifungal activities of these compounds has revealed that 2-m-hydroxyphenyl-7-methyl-9-bromo-chromono (6, 7) oxazole and 2-p-Anisyl-7-methyl-9-bromo-chromono (6, 7) oxazole possess antifungal activity.     

Spectrophotometric and potentiometric investigations of copper (II)-Ethanolamine complexes

Spectrophotometric and potentiometric investigations have been carried out on copper-diethanolamine system. Job plots at 900, 900 and 580 mμ have indicated the formation of CuD⁺⁺, CuD₂ ⁺⁺ and CuD₃ ⁺⁺. Then- pA curves obtained indicate the formation of CuD⁺⁺, CuD₂ ⁺⁺, CuD₃ ⁺⁺, CuDOH⁺, CuD₂OH⁺ and CuD₃OH⁺. Then- pA curves have been analyzed to obtain the stability constants of these complexes. Absorption curves of pure complexes have been computed by a graphical method. Gaussian analysis of the absorption curves of pure and hydroxy complexes show the presence of a second band, indicating that the structure is that of a distorted octahedron.     

Dinuclear copper (II) and nickel (II) systems with planar M2N2O2 bridge

The tridentate ligand systemb (abbreviated as inkR₂) readily yield copper (II) and nickel (II) species of the formula M₂ (inkR₂)₂(CLO₄)₂. 2xH₂O (x=0–1). Dinuclear formulation is based on variable temperature magnetic susceptibility and conductivity data and on the known structure of some related systems. The Cu₂ (inkR₂) ₂ ²⁺ species are strongly antiferromagnetic (?2J=600–800 cm^?1) while the Ni₂(inkR₂) ₂ ²⁺ species are diamagnetic. The major coordination sphere is planar around each metal (II). The metal ions in a dimer are linked by planar M₂N₂O₂ bridge. The copper (II) and nickel (II) species freely form solid solutions. In these statistical scrambling of copper and nickel occur among the metal ion sites of the dimeric structure. Powder epr spectra of such mixed crystals are indicative of axial geometry around copper (II) ion.     

Search for physiologically active compounds: Part XXVIII. Synthesis of 7-chloro-2-methyl and 2-(2-furyl), 3-aryl-4-quinazolones

A number of 2-methyl-3-aryl-7-chloro and 2-(2-furyl)-3-aryl-4-quinazolones have been synthesised by condensing N-acyl anthranilic acids with primary aromatic amines using phosphorus trichloride in dry toluene. All these quinazolone derivatives have been screened for their antibacterial, antifungal and fishtoxic properties.     

The correlations of finite Desarguesian planes, Part III: The classification (II)

This paper continues the classification of the correlations of planes of odd nonsquare order. Part I (Generalities) included introductory definitions and results (Section 1), algebraic preliminaries (Section 2), as well as a discussion of equivalent correlations (Section 3) and of their general properties (Section 4). The classification proper revolves around a special polynomial which can have one, two, or q + 1 zeros, or no zeros at all, and each of these four possibilities leads to different families of correlations. Part II contained Section 5, devoted to the cases in which the correlation is defined by a diagonal matrix (Subsection 5.1) or the polynomial in the preceding paragraph possesses q + 1 zeros (Subsection 5.2), one zero (Subsection 5.3) and two zeros (Subsection 5.4). Subsection 5.5 presented certain results to be used in the subsequent sections. The present article contains Section 6, devoted to the case in which the above-mentioned polynomial has no zeros.     

On the classification of all self-dual additive codes over GF(4) of length up to 12

We consider additive codes over GF(4) that are self-dual with respect to the Hermitian trace inner product. Such codes have a well-known interpretation as quantum codes and correspond to isotropic systems. It has also been shown that these codes can be represented as graphs, and that two codes are equivalent if and only if the corresponding graphs are equivalent with respect to local complementation and graph isomorphism. We use these facts to classify all codes of length up to 12, where previously only all codes of length up to 9 were known. We also classify all extremal Type II codes of length 14. Finally, we find that the smallest Type I and Type II codes with trivial automorphism group have length 9 and 12, respectively.     

New Extremal Type II Codes Over ℤ4

Recently Type II codes over ℤ₄ have been introduced as self-dual codes containing the all-one vector with the property that all Euclidean weights are divisible by eight. The notion of extremality for the Euclidean weight has been also given. In this paper, we give two methods for constructing Type II codes over ℤ₄. By these methods, new extremal Type II codes of lengths 16, 24, 32 and 40 are constructed from weighing matrices.     

Mode I,mode II,and mixed-mode I/II interlaminar fracture toughness of GFRP influenced by fiber surface treatment

The interlaminar fracture behavior of unidirectional glass fiber reinforced composites with fiber surface treatment has been investigated in modes I and II and for fixed mode I to mode II ratio of 1.33. The data obtained from these tests have been analyzed by using different analytical approaches. The present investigation is focused on the influence of the glass fiber surface treatment on the interlaminar fracture toughness of unidirectional laminates. Glass fibers with two different fiber surface treatments have been investigated. fiber surface treatment was carried out by using a polyethylene or silane coupling agent in combination with modifying agents. The glass fibers were embedded in the brittle epoxy matrix. Mode I, mode II, and mixed-mode I/II tests were performed in order to determine critical strain energy release rates. Double cantilever beam (DCB), end-notched flexure (ENF), and mixed-mode flexure (MMF) specimens were used. For both types of fiber surface treatment about the same values of mode I initiation fracture toughness G_IC ^init were obtained. It was observed that in mode I interlaminar crack growth in the DCB test for the composite sized by polyethylene, the crack propagation is accompanied by extensive fiber bridging. For both fiber surface treatments interlaminar fracture toughness increases considerably with increasing of crack length. For the fiber surface treatment with the silane coupling agent, the value of mode II initiation fracture toughness G_IIC ^init was about 2.5-times higher in comparison with that of a composite sized by polyethylene. For both types of fiber surface treatments the mixed-mode I/II test has shown a similar behavior to the mode I DCB test.     

CAT(0) spaces with polynomial divergence of geodesics

We construct a family of finite 2-complexes whose universal covers are CAT(0) and have polynomial divergence of desired degree. This answers a question of Gersten, namely whether such CAT(0) complexes exist.     

Euler-Mahonian statistics on ordered set partitions (II)

[E. Steingrímsson, Statistics on ordered partitions of sets, arXiv: math.CO/0605670] introduced several hard statistics on ordered set partitions and conjectured that their generating functions are related to the q-Stirling numbers of the second kind. In a previous paper, half of these conjectures have been proved by Ishikawa, Kasraoui and Zeng using the transfer-matrix method. In this paper, we shall give bijective proofs of all the conjectures of Steingrímsson. Our basic idea is to encode ordered set partitions by a kind of path diagrams and explore the rich combinatorial properties of the latter structure. As a bonus of our approach, we derive two new σ-partition interpretations of the p,q-Stirling numbers of the second kind introduced by Wachs and White. We also discuss the connections with MacMahon's theorem on the equidistribution of the inversion number and major index on words and give a partition version of his result.     

Hilbert空间中的g-Bessel序列的一些等式与不等式(II)

Hilbert 空间中的g- 框架是框架的自然推广, 它们包含了许多推广的框架, 如子空间框架或fusion 框架、斜框架和拟框架等. 它们有许多与框架类似的性质, 但是并不是所有的性质都是相似的.例如, 无冗框架等价于Riesz 基, 但是无冗g- 框架不等价于g-Riesz 基. 一些作者将Hilbert 空间中的框架和对偶框架的等式和不等式推广到g- 框架和对偶g- 框架. 本文建立Hilbert 空间中的g-Bessel序列或g- 框架的一些新的等式和不等式. 本文还给出这些不等式的等号成立的充要条件. 这些结果推广和改进了由Balan, Casazza 和G?vruta 等得到的著名结果.     

DISTORTION THEOREM FOR BIHOLOMORPHIC MAPPINGS IN TRANSITIVE DOMAINS(Ⅱ)

Based on [1], this paper gives concrete estimates for distortion theorem for biholomorphic convex mappings in classical domains of types Ⅰ, Ⅱ, and Ⅲ including transitive domains which are holomorphically homeomorphic to these domains.     

Spectrophotometric studies of 6-methyl pyridine-2-aldoxime-iron (II) complex

6-Methyl pyridine-2-aldoxime produces with iron (II) solution a deep red complex soluble in 50% (by volume) aqueous acetone. The complex is stable at 10–45°C. and its colour intensity does not vary between pH 7·3 and 10·0. The complex obeys Lambert-Beer’s law at 520 mµ in the concentration range of 1·12 to 28·0 p.p.m. of iron.     

Reguläre Inzidenzkomplexe II

The concept of regular incidence complexes generalizes the notion of regular polyhedra in a combinatorial and grouptheoretical sense. A regular (incidence) complex K is a special type of partially ordered structure with regularity defined by the flag-transitivity of its group A(K) of automorphisms. The structure of a regular complex K can be characterized by certain sets of generators and ‘relations’ of its group. The barycentric subdivision of K leads to a simplicial complex, from which K can be rebuilt by fitting together faces. Moreover, we characterize the groups that act flag-transitively on regular complexes. Thus we have a correspondence between regular complexes on the one hand and certain groups on the other hand. Especially, this principle is used to give a geometric representation for an important class of regular complexes, the so-called regular incidence polytopes. There are certain universal incidence polytopes associated to Coxeter groups with linear diagram, from which each regular incidence polytope can be deduced by identifying faces. These incidence polytopes admit a geometric representation in the real space by convex cones.     

The Beijing Astronomical Observatory supernova survey (II)

Six supernovae (SNe) discovered in 1996 by the Beijing Astronomical Observatory Supernova (SN) Survey (BAOSS) are reported. SN 1996W, the first supernova discovered by the survey, has been monitored photometrically and spectroscopically for a long time. The spectra and photometry showed that it was a typical type II-P supernova. SN 1996cb, the sixth SN discovered in 1996 and a peculiar one like SN 1993J, has also been observed intensively for a long time. Project supported by the National Natural Science Foundation of China (Grant No. 19733020).