Adaptive finite-time prescribed performance control for stochastic nonlinear systems with unknown virtual control coefficients

Nonlinear Dynamics - This paper is devoted to the adaptive finite-time prescribed performance control (FTPPC) for stochastic nonlinear systems with unknown virtual control coefficients (UVCCs),...     

二(邻香草醛缩丙醇胺)异硫氰酸根合锰(Ⅲ)的合成与晶体结构

本文报道了一个新配合物—二(邻香草醛缩丙醇胺根)异硫氰酸根合锰(Ⅲ)的合成及其晶体结构。配合物属于单斜晶系，空间群为P2₁/c，晶胞参数为：a=8.565(1), b=21.814(2), c=12.787(2)?, β=92.80(1)°。锰为六配位，在两个邻香草醛缩丙醇胺Schiff碱配体中，一个为三齿配体，另一个为双齿配体。NCS^-离子以N在轴向上与锰发生配位，由于Jahn-Teller效应，其键长为2.193?。另外晶胞中存在着罕见的H……S-C≡N氢键。     

Search for improved host architectures: application of de novo structure-based design and high-throughput screening methods to identify optimal building blocks for multidentate ethers

This paper presents a computational approach to the deliberate design of improved host architectures. The approach, which involves the use of computer-aided design software, is illustrated by application to cation hosts containing multiple aliphatic ether oxygen binding sites. De novo molecule building software, HostDesigner, is interfaced with molecular mechanics software, GMMX, providing a tool for generating and screening millions of potential bidentate building block structures. Enhanced cation binding affinity can be achieved when highly organized building blocks are used to construct macrocyclic hosts.     

Synthesis and crystal structure of manganese(III) hydroxyl-containing Schiff base complexes: [Mn(III)(Hvanpa)2]N3 (H2vanpa = 1−(3-hydroxysalicylaldeneamino)-3-hydroxypropane)

The manganese complex, [Mn(III)(Hvanpa)₂]N₃ has been prepared and the crystal structure determined using x-ray crystallography. The mononuclear complex has a six-coordinate octahedral geometry. The complex crystallizes in the monoclinic space group P2₁/c with a = 9.867(1), b = 13.316(2), c = 9.0110(1) Å, = 107.870(1)°, V = 1126.8(2) ų, and Z = 2. The Mn-O and Mn-N distances in the equatorial plane are in good agreement with those found for other manganese(III) Schiff base complexes. In the axial direction, the Mn-O distances of 2.274(2) Å is about 0.3 Å longer than those in the equatorial plane due to a Jahn-Teller distortion at the d⁴ manganese(III) center. In the crystal, each azido ion is linked through hydrogen bonding with two hydrogen atoms from the coordinate hydroxyl groups at the apical site.     

Crystal structure of 1-chloroanthraquinone

The X-ray crystal structure of 1-chloroanthraquinone is determined. The compound C₁₄H₇O₂Cl, is monoclinic in P2₁(#4) with a = 7.763(1), b = 3.973(2), c = 16.947(1) Å, = 95.13(1)°, V = 520.6(3) ų, D _calc = 1.548 g/cm³, and Z = 2. In the molecular structure, the Cl atom is obviously repelled by O(1). The major force of crystal formation comes from aromatic ring stacking and C–H-aromatic interaction.     

Six-coordinated zinc complexes: [Zn(H2O)4(phen)] (NO3)2·H2O and [ZnNO3(H2O)(bipy)(Him)]NO3 (phen = 1,10-phenanthroline, bipy = 2,2′-bipyridine, and Him = imidazole)

Two novel six-coordinated zinc complexes, tetra-aqua(1,10-phenanthroline)zinc dinitrate monohydrate, [Zn(H₂O)₄(phen)](NO₃)₂·H₂O (1) and aqua(2,2-bipyridine)(imidazole)-nitratozinc nitrate, [ZnNO₃(H₂O)(bipy)(Him)]NO₃ (2) were prepared. Compound 1 crystallizes in the monoclinic space group P2₁/c with a = 8.780(4), b = 13.609(4), c = 15.368(5) Å, = 93.86(2)°C, V = 1832.1(12) ų. In 1, a phenanthroline molecule chelates the zinc atom and four water molecules complete the octahedral geometry around the metal. Compound 2 crystallizes in the monoclinic space group P2₁/n with a = 7.250(1), b = 24.554(4), c = 10.258(2) Å, = 107.880(10)°, V = 1737.9(5) ų. In 2, a bipyridine molecule and a nitrate anion chelate the zinc atom. An imidazole molecule and a water molecule then complete the six-coordinated geometry around zinc. The intermolecular packing is controlled by hydrogen bonding, especially in 1 and by stacking. The thermal stability of the compounds and the loss of water molecules and ligands was monitored by a thermogravimetric study.     

Bis­[3‐(salicyl­idene­amino‐O,N)propanolato]manganese(III) perchlorate

In the complex [Mn(C₁₀H₁₂NO₂)₂]ClO₄, the Mn atom lies on an inversion centre and the Cl of the perchlorate is on a twofold axis. In the cation, the Mn atom has distorted octahedral coordination with Mn—N 2.206 (3), Mn—O(phenolato) 1.871 (2) and Mn—O(propanolato) 2.300 (2) Å. In the crystal structure, the ions are linked by O—H?O hydrogen bonds [O?O 2.826 (4) Å] between the propanolato O—H group and a perchlorate O atom to form infinite chains. This is not what was proposed from a previous spectroscopic study.     

智能动画创作系统 PNAI 的研究进展

计算机动画制作是一件十分耗费时间的工作,提高计算机动画的效率是一项重要的研究课题.近几年我们研制的计算机动画生成系统中的3个底层子系统以及其中涉及的方法,为计算机动画生成提供了有效的支持.在场景设计方面,我们提出了基于场景实例和场景设计知识的场景设计方法;在自动摄影中,我们提出了一种基于摄影脚本的摄影方法;在脸部动画方面,我们采用了RBF方法以及利用了一些预先编成的MEL脚本     

Design, synthesis, and structure of novel cesium receptors

The podand, bis(2-methoxyphenoxy)m-xylene (1), was designed and synthesized as a potential host for the cesium ion. Its structure was determined by single crystal X-ray diffraction. It crystallizes in P2₁/c with cell dimensions: a = 8.5723(7) Å, b = 8.3931(14) Å, c = 25.2879(26) Å, = 96.224(9), and V = 1808.7(4) ų. A crown derivative, tribenzo-21-crown-6 (2), was also prepared and structurally characterized. It also crystallizes in P2₁/c with cell dimensions: a = 15.5825(13) Å, b = 15.8648(16) Å, c = 8.8266(7) Å, = 95.247(6), and V = 2172.9(3) ų. The structures exhibit hydrogen bonding, and are evaluated in terms of complementarity and preorganization for cesium binding.     

氧络锰(Ⅳ)卟啉与烯烃反应的研究

单加氧酶细胞色素P-450在生物体中温和条件下活化分子氧,选择性地催化氧化碳氢化合物,其活性中间体可能是氧络铁原卟啉Ix的配合物。锰卟啉配合物也在温和条件下活化分子氧,选择性地催化氧化碳氢化合物,其活性中间体也可能是氧络锰卟啉配合物,是细胞色素P-450的很好的模型体系。目前人们已用一系列的氧化剂,诸如氧化碘苯(PhIO)、NaOCl、KHSO_5、RCOOOH、HCIO_4和HIO_4将三价的锰卟啉氧化为氧络锰卟啉。本实验