拟亚纯映射的充满圆

该文用较简明的方法讨论了平面上K 拟亚纯映射在\{lim[DD(X]r→∞[DD)]\}[TX-][SX(]S(r,f)[]lgr[SX)]=∞ 条件下及有限正级K 拟亚纯映射存在充满圆序列, 同时也证明了零级K 拟亚纯映射的最大型Borel方向及有限正级Borel方向上存在充满圆序列.     

FOURIER TRANSFORM FAR INFRARED SPECTRA AND NORMAL COORDINATE ANALYSIS OF FIFTEEN RARE-EARTH OXALATE HYDRATES

The Fourier transform far infrared spectra of oxalate hydrates of whole rare-earth series except Pm and Sc are investigated in the range of 100-400 cm~(-1). The assignment of vibrational frequencies is made on the basis of normal coordinate analysis using our NORVIB program. The model used for the hghter elements of the lanthanide series (La to Eu) is based on the crystal structure of Nd_2(C_2O_4)_3. 10H_2O, in which each lanthanide ion is surrounded by nine O atoms, six from three oxalate ions and three from Water molecules.The model adopted for the heavier elements of the lanthanide series (Gd to Lu) and Ytterbium is based on the crystal structure of Yb_2(C_2O_4)_3· 6H_2O, in which each ion is surrounded by eight atoms, six from three oxalate ions and two from water molecules. The variation of the metal-ligand frequencies and force constants with the atomic numbers of lanthanides is plotted and discussed.     

On duality between observation and control for implicit linear discrete-time systems

Some results concerning the problem of duality between observationand control for implicit linear discrete-time systems are presented.It is not assumed that the considered systems are regular. Inthis case, some new concepts of observability and controllabilityturn out to be necessary for studying the problem of duality.     

An Object Grammar for Column-Convex Polyominoes

In this paper we propose an object grammar decomposition for the classes of columnconvex, and directed column-convex polyominoes. As a consequence, we obtain the enumeration of such classes according to the semi-perimeter, thus giving a natural explanation of the fact that the generating functions of both the classes are algebraic.AMS Subject Classification: 05A15.     

Uniform-fast-gerade Funktionen mit vorgegebenen Werten,II

For a given sequence n₁ < n₂ < ... of integers satisfying and for a given convergent sequence of complex numbers {a_j}, it was shown in [4] that there is a uniformly-almost-even function assuming the values f(n_j) = a_j. For the proof, Gelfands theory of commutative Banach algebras and Tietzes extension theorem were used. In [3] an incomplete proof [by elementary means] of this result was given.¹⁾The aim of this note is to give some results which can be proved by the method from [3].¹⁾The first-named author is grateful to the second author for pointing out a missing case in the above-mentioned proof.Received: 7 November 2002     

A tantalum electrode coated with graphene nanowalls for simultaneous voltammetric determination of dopamine,uric acid,L-tyrosine,and hydrochlorothiazide

The authors describe a voltammetric sensor for simultaneous determination of dopamine (DA), uric acid (UA), L-tyrosine (Tyr), and the diuretic drug hydrochlorothiazide (HCTZ). The assay is based on the use of graphene nanowalls deposited on a tantalum substrate. The nanowalls are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy, and cyclic voltammetry. The nanowalls are vertically grown on the substrate by direct-current arc plasma jet chemical vapor deposition. The modified electrode is shown to enable simultaneous differential pulse voltammetric determination of DA, UA, Tyr, and HCTZ. The graphene nanowalls display a large specific surface, high conductivity, and a large number of catalytically active sites for oxidation of analytes. Simultaneous detection is performed best at a pH value of 7.0 and at peak potentials of 0.124 V (vs. SCE) for DA, 0.256 V for UA, 0.536 V for Tyr and 0.708 V for HCTZ. The respective detection limits are 0.04 μM, 0.1 μM, 0.6 μM and 0.4 μM. The results show that this graphene wall modified electrode is a promising tool for the design of sensitive, selective, and stable sensors.

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Graphical abstract The graphene-based differential pulse voltammetric sensor for simultaneous determination of dopamine, uric acid, L-tyrosine, and hydrochlorothiazide exhibits high selectivity, sensitivity, and stability.