Photophysics of Genistein isoflavone: Solvent and concentration effects studied by UV–visible spectroscopy and theoretical simulation

Genistein isoflavone is shown to exist in two different conformations which are the 90° completely twisted geometry and the 50° less twisted one. Specific interactions with the solvent cage as well as self-association processes seem shifting the isoflavone from the perpendicular conformation towards the less twisted one. The theoretical simulation, using analytical atom–atom pair potential, predicts a self-dimer in a slipped non-sandwich, face to river, perpendicular structure. From the UV–visible photophysics investigations it is revealed that monomeric species cannot exist alone even at very low solute concentration (10⁻⁶ M), the self-association process occurs already in this concentration range.     

Crystal structure of a dimeric copper(II) complex with N,N -diethylethylenediamine (dien): a model for the thermally and photoinduced violet forms of the bis(dien)copper(II) cation

The molecular structure of the violet dimer bis(μ-hydroxo)bis(N,N-diethylethyl- enediamine)dicopper(II) perchlorate supports the hypothesis that the photoinduced phase of the monomer bis(N,N-diethylethylenediamine)copper(II) perchlorate, similar to the corresponding, high temperature, thermally induced phase, features tetrahedral distortion of the square planar coordination.     

群代数Ore扩张的量子群

本文讨论由Beattie通过群代数的Ore扩张所构造的量子群的中心和Yang－Baxter模范畴．此外,完全刻画了这类量子群的不可约表示．     

关于一致凸空间中联合逼近的一个特征

文中给出了一致凸空间中 Chebyshev中心的一个特征 ,推广了 D.Amir和 J.Mach关于 Hilbert空间中的一个结果 .     

New solutions of classical problems in rigid body dynamics

The equations of motion of a rigid body acted upon by general conservative potential and gyroscopic forces were reduced by Yehia to a single second-order differential equation. The reduced equation was used successfully in the study of stability of certain simple motions of the body. In the present work we use the reduced equation to construct a new particular solution of the dynamics of a rigid body about a fixed point in the approximate field of a far Newtonian centre of attraction. Using a transformation to a rotating frame we also construct a new solution of the problem of motion of a multiconnected rigid body in an ideal incompressible fluid. It turns out that the solutions obtained generalize a known solution of the simplest problem of motion of a heavy rigid body about a fixed point due to Dokshevich.     

Banach upper density recurrent points of <Emphasis Type="Italic">C</Emphasis><Superscript>0</Superscript>-flows

Let X denote a compact metric space with distance d and F:X×R→X or F_t:X→X denote a C⁰-flow. From the point of view of ergodic theory, all important dynamical behaviors take place on a full measure set. The aim of this paper is to introduce the notion of Banach upper density recurrent points and to show that the closure of the set of all Banach upper density recurrent points equals the measure center or the minimal center of attraction for a C⁰-flow. Moreover, we give an example to show that the set of quasi-weakly almost periodic points can be included properly in the set of Banach upper density recurrent points, and point out that the set of Banach upper density recurrent points can be included properly in the set of recurrent points.     

Random Sequential Adsorption on Random Trees

When gas molecules bind to a surface they may do so in such a way that the adsorption of one molecule inhibits the arrival of others. Two models which have frequently been studied are the “dimer model” and the “blocking model”, and rather complete solutions for these are known on fixed tree structures or Bethe lattices. In this paper comparisons are made between the occupation probabilities for vertices between fixed and random trees.     

NMR Study of Hetero‐Association Accompanying Self‐Association of 2‐Hydroxyl‐4‐methyl‐pyridine and 2‐Pyrrolidone in Acetonitrile

This work in vestigated not only the equilibrium of self‐association of 2‐pyrrolidone (A) and that of 2‐hydroxyl‐4‐methyl‐pyridine (B), but also the hetero‐association between A and B in [²H₃]acetonitrile through hydrogen bonding using high‐resolution nuclear magnetic resonance spectroscopy. Dilution shift data for the protons of the NH group of A and OH group of B were measured over a wide range of temperatures and concentrations. In addition, the monomer shifts, dimer shifts and dimerization constants of self‐association and hetero‐association were evaluated using a graphic method operating on the dilution chemical shift data. The enthalpy and entropy of dimerization of self‐association and hetero‐association were also obtained from the van't Hoff plot.     

量子群U_q(sl(2 ) )的非负部分(英文)

设U≥ 0 是量子群Uq(sl(2 ) )的非负部分 .在本文中 ,我们确定了U≥ 0 的中心Z(U≥ 0 )和U≥ 0 的所有不可约表示     

Classroom note: A Generalization of Leibniz rule for higher derivatives

This note provides a simple method to extend the usual Leibniz rule for higher derivatives of the product of two functions to several functions, which is within the reach of freshman calculus students.