Noisy colored point set matching

We propose a process for determining approximated matches, in terms of the bottleneck distance, under color preserving rigid motions, between two colored point sets A,B∈R², |A|≤|B|. We solve the matching problem by generating all representative motions that bring A close to a subset B^′ of set B and then using a graph matching algorithm. We also present an approximate matching algorithm with improved computational time. In order to get better running times for both algorithms we present a lossless filtering preprocessing step. By using it, we determine some candidate zones which are regions that contain a subset S of B such that A may match one or more subsets B^′ of S. Then, we solve the matching problem between A and every candidate zone. Experimental results using both synthetic and real data are reported to prove the effectiveness of the proposed approach.     

Trifluorosulfane ligand as an analogue of the nitrosyl ligand: highly exothermic fluorine transfer reactions from sulfur to metal in the chemistry of SF3 metal carbonyls of the first row transition metals

The variety of known very stable PF(3) metal derivatives analogous to metal carbonyls suggests the synthesis of SF(3) metal derivatives analogous to metal nitrosyls. However, the only known SF(3) metal complex is the structurally uncharacterized (Et(3)P)(2)Ir(CO)(Cl)(F)(SF(3)) synthesized by Cockman, Ebsworth, and Holloway in 1987 and suggested by electron counting to have a one-electron donor SF(3) group rather than a three-electron donor SF(3) group. In this connection, the possibility of synthesizing SF(3) metal derivatives analogous to metal nitrosyls has been investigated using density functional theory. The [M]SF(3) derivatives with [M] = V(CO)(5), Mn(CO)(4), Co(CO)(3), Ir(CO)(3), (C(5)H(5))Cr(CO)(2), (C(5)H(5))Fe(CO), and (C(5)H(5))Ni analogous to known metal nitrosyl derivatives are all predicted to be thermodynamically disfavored with respect to the corresponding [M](SF(2))(F) derivatives by energies ranging from 19.5 kcal/mol for Mn(SF(3))(CO)(4) to 5.4 kcal/mol for Co(SF(3))(CO)(3). By contrast, the isoelectronic [M]PF(3) derivatives with [M] = Cr(CO)(5), Fe(CO)(4), Ni(CO)(3), (C(5)H(5))Mn(CO)(2), (C(5)H(5))Co(CO), and (C(5)H(5))Cu are all very strongly thermodynamically favored with respect to the corresponding [M](PF(2))(F) derivatives by energies ranging from 64.3 kcal/mol for Cr(PF(3))(CO)(5) to 31.6 kcal/mol for (C(5)H(5))Co(PF(3))(CO). The known six-coordinate (Et(3)P)(2)Ir(CO)(Cl)(F)(SF(3)) is also predicted to be stable relative to the seven-coordinate (Et(3)P)(2)Ir(CO)(Cl)(F)(2)(SF(2)). Most of the metal SF(3) complexes found in this work are singlet structures containing three-electron donor SF(3) ligands with tetrahedral sulfur coordination. However, two examples of triplet spin state metal SF(3) complexes, namely, the lowest energy (C(5)H(5))Fe(SF(3))(CO) structure and a higher energy Co(SF(3))(CO)(3) structure, are found containing one-electron donor SF(3) ligands with pseudo square pyramidal sulfur coordination with a stereochemically active lone electron pair.     

Gas sensing of colloidal polyaniline in a chemoresistor consisting of nanometer electrodes

The high conductivity of colloid-conducting polymers is explained by the networking structures and the hopping mechanisms of the metallic particles [1], [2] and [4]. To observe how the metallic region and the networking structures differ in sensing NH₃ gas, E-beam lithography and electromigration were used to make chemoresistors with nanometer-gap electrodes. Colloid Pani was coated on a nanometer gap as a reaction matrix for the gas. The I-V curves were measured in a vacuum and the NH₃ gas was nonlinear. In sensors with a gap of less than 10 nm, there was a two- or threefold increase in the conductivity, and the work function decreased from 600 meV in a vacuum to 250 meV in NH₃ gas. In contrast, the conductivity of sensors with gaps of 200 and 500 nm decreased to 1/1000 in the NH₃ gas environment. The decrease of the conductivity can be explained by electron-hole annihilation, which appears to occur on the surface of the secondary particles. With comb-type electrodes, the operating voltage can be decreased by three orders of magnitude. In electrodes with 200 and 500 nm gaps, the I-V has a step-type response to NH₃ gas.     

SERS spectroscopy and SERS imaging of Shewanella oneidensis using silver nanoparticles and nanowires

Facile and reproducible SERS signals from Shewanella oneidensis were obtained utilizing silver nanoparticles (AgNPs) and silver nanowires (AgNWs). Additionally, SERS images identify the distribution of SERS hot-spots. One important observation is the synergistically enhanced SERS signal when AgNPs and AgNWs are used in conjunction, due to constructively enhanced electromagnetic field.     

垂直加热管外自由降膜流的破断特性

在较宽液膜雷诺数和进口温度范围内对垂直加热管外自由降膜流破断特性进行了实验研究。应用热物理学相似分析的方法整理实验数据，给出新的破断准则数综合关系式，并与１９９３年发表的另一些作者的结果作了比较。实验参数的变化范围如下：ｔｉｎ＝２０～９０℃，最大液膜雷诺数Ｒｅ为１．２１×１０４，最大热流密度达１．３９×１０５ｗ／ｍ２。